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Coal as a Source of Electrical Energy in Bangladesh

INTRODUCTION

Electrical power is the corner stone of national economy. Electricity can be generated from many sources. Fossil fuel – oil, coal and natural gas dominates power generation. World reserve of fossil fuel resource is fast depleting .Moreover, burning of non fossil fuel is triggering global warming through green house gas emission. Floods, draught, cyclones, tornados, bushfires are causing massive destruction in different countries. People are turning to renewable sources – solar, wind, wave, geothermal, hydroelectricity, nuclear power generation is also getting popularity. Most of the countries have well crafted and professionally managed energy policy. Many countries have regional energy grid for energy trading.

Bangladesh is very lucky that it has got substantial natural gas reserve and significant but almost untapped high quality coal resource. There is also plenty of scope to generate solar power, wind power and energy from bio fuels. Many countries of the world like Japan, Korea do not have any fossil fuel resource yet they are among the top developed nations. They import almost their entire requirement of the fuel for energy generation from highly competitive energy market. Several countries do not have enough basic fuel to meet their huge demand. These countries import energy from energy rich countries to fuel their economy.

Unfortunately our small country Bangladesh of 160 million people has no appropriate strategy. There is an energy policy which is not properly administered.

Electricity generation in Bangladesh is overwhelmingly gas based. More than 85 percent of evening peak demand is catered by natural gas .This is followed at a distant by liquid fuel, and coal with generation shares of 6.76 percent and 5.41 percent respectively. Hydropower accounts for insignificant 2.45 percent of generation. The fuel mix if recalculated using the derated generation capacity, share of gas based generation reduces marginally to 83.45percent; share of liquid fuel and hydro based generation increases to 7.55 percent and 4.60 percent respectively.

The production and supply of natural gas is grossly inadequate. Natural gas is also used as feedstock for fertilizer production, as fuel for many industries, as compressed natural gas for automobiles. It is also used by commercial and domestic consumers. It is said that against a national demand of 2200 MMCFD our production capacity is 1880MMCFD Consequently the deficit is seriously impacting upon power generation and operation of fertilizer plants and other gas using industries. For several years some international oil companies having exploration rights in several exploration blocks did not do any work and now most of them are relinquishing these blocks. Petrobangla companies also failed to implement reservoir reassessment of major gas fields and expand production. So It is not in a position to carry out all its responsibilities. In this situation the remaining 6tcf reserve of natural gas may run out by 2015 if no new discovery is made soon

Bangladesh is now suffering from the worst energy crisis of its history. Entire country is suffering from 8-10 hours load shedding on the average despite of the fact that only 35% of its 15 million people have direct access to power supply. Industrial growth has come to almost standstill due to inadequate gas supply. Existing industries cannot be operated properly due to unsteady supply of energy.

The coal reserves in five fields of Bangladesh are estimated at 3.0 billion tonnes equivalent to 67 tcf of gas, which can conveniently serve the energy needs of Bangladesh for 50 years. Recovery rate of coal from reserves varies with the choice of technology and method of mining. If modern mining technology can be adopted ensuring strong regulatory supervision and monitoring about 85% coal from Barapukuria, Phulbari and Dighipara can be recovered. Khalaspeer can be ideal candidate for Coal Seam methane while we can wait for some years for technological development for mining giant Jamalganj coal mine.

Now, appropriate strategy should be adopted to explore and exploit coal, the only other major energy resource. In the present crisis situation it is felt prudent to discuss about coal situation in Bangladesh. From the information presented in a recent discussion in Dhaka we find Bangladesh does not have any choice but to start coal mining without delay adopting technically appropriate and economically feasible and environmentally friendly mining method.

PRESENT STATE OF ELECTRICITY IN BANGLADESH

Bangladesh is an energy hungry country. Power infrastructure of Bangladesh is small and insufficient but the demand is rapidly increasing. The per capita power consumption in Bangladesh is about 136kwh which is one of the lowest in the world but for huge population density our power sector is in enormous pressure. In Bangladesh, electricity is the major source of power and most of the economical activities depends on electricity.

Generation of electricity

Total electric power generation (installed) capacity of Bangladesh is 5823MW [BPDP, June 2010] and only three-fourth of which is considered to be available. The present [Feb, 2011] effective power generation capacity per day is about 4000 MW and the demand is 5000MW.  Only 40% of our total population has the access to electricity and in rural areas it is less than that .

Table  Electricity generation per year (from 2003 to 2011)

Year Electricity – production(kwh) Percent Change Date of Information
2003 15,330,000,000 2001
2004 15,330,000,000 0.00 % 2001
2005 16,450,000,000 7.31 % 2002
2006 17,420,000,000 5.90 % 2003
2007 18,090,000,000 3.85 % 2004
2008 22,780,000,000 25.93 % 2007 est.
2009 22,780,000,000 0.00 % 2007 est.
2010 22,990,000,000 0.92 % 2007 est.
2011 25,620,000,000 11.44 % 2009 est.

In past few years, generation of electricity have been increases in a considerable amount but demand increases more than that, so our generation plants have been unable to meet system demand for a long time.

 Bangladesh has small reserves of oil and coal, but potentially very large natural gas resources that’s why, most of the generation plant used natural gas as fuel. Some coal, diesel, furnace oil is also used in production of electric power. About 87% of our total electric power is produced by natural gas, 5.75 % by furnace oil, 4.29 % by coal, 3.19 % by diesel and 3.95 % is produced from hydro electric plant.

Generation (installed) capacity by fuel type

Figure Generation (installed) capacity by fuel type(as june 2010)

Distribution and consumption

In Bangladesh, electricity distribution system in controlled by national grid. Total electric power, generated from the power plants is first supplied to the national grid then to the hole counrty through national grid. The Padma-Jamuna-Meghna river divides power distribution sytem  into two zones, East and West. The East contains nearly all of the country’s electric generating capacity, while the West, with almost no natural resources, must import power from the East. Electricity interconnection from the East to the West was accomplished in 1982 by a new, 230-kilovolt (kV) power transmission line. The vast majority of Bangladesh’s electricity consumption takes place in the East, with the entire region west of the Jamuna River accounting for only 22% of the total. There are many organizations to distribute electric power in hole country. Dhaka electric supply authority (desa),   Dhaka electric supply company (desco), dhaka power development corporation (DPDC),  rural electrification board (REB), west zone power development company limited (WZPDCL) etc. All of these companies have their own power demand and the demand is given below in the chart-

 3 Consumption pattern of electric power

Figure  Consumption pattern of electric power (%)

In last few years power consumption in bangladesh is increased in such a high rate that, inspite of  increasing the power generation in a considerable amount , our power system doesn’t meet the goal and still we have a large amount of power shortage. Power consumption of last few years are as following –

Table Yearly power consumption (from 2003 to 2011)

year Electricity – consumption(kwh) Percent Change Date of Information
2003 14,260,000,000 2001
2004 14,250,000,000 -0.07 % 2001
2005 15,300,000,000 7.37 % 2002
2006 16,200,000,000 5.88 % 2003
2007 16,820,000,000 3.83 % 2004
2008 21,370,000,000 27.05 % 2006 est.
2009 21,370,000,000 0.00 % 2006 est.
2010 21,380,000,000 0.05 % 2007 est.
  2011 23,940,000,000 11.97 %                      2009 est.

yearly electric power consumption

Figure : yearly electric power consumption

key problems in power sector

Load shedding and voltage variation

The state-owned Bangladesh Power Development Board (BPDB), which controls nearly three-fourths of the total generation capacity in Bangladesh, has resorted to load shedding as a means to reconcile demand to the available capacity. Load shedding is a significant constraint on growth of the economy.

 Operating Inefficiency

The power sector does not fare well in terms of operating efficiency. For example, Bangladesh requires considerably more employees per customer served than is the case in many countries.

System loss

System loss occurs both for technical reasons and for reasons of inefficiency and corruption in administration. Exact figures of loss are unknown but, at approximately 30 per cent, the net country-wide system loss is probably among the highest in the developing world. The losses incurred differ dramatically across the various utilities.
 Unadjusted tariff structures and ineffective billing procedures

Many countries have been unable to establish tariff structures and billing procedures that enable the power sector to be financially self-supporting. The resulting losses require subsidies from government or donor agencies that divert revenue away from other important programmes,such as education and public health. This problem has afflicted the Bangladesh power sector entities to varying degrees.

Recommendations

Bangladesh is a developing country and most serious challenges we faces is power crisis. What ever we forecast for demand but our calculation failed because if you produce right now 7000 megawatt, it will fulfill with in a very short time because of many development and industries are waiting for power. If power is available, we will see many new projects, industries will consume immediately.

In electricity, when we save power it means we produce power. If somebody save 100 watt, another user can use that power. Therefore energy efficiency is essential in every electric product. All the develop world even India also have energy efficiency authority to motivate and regulating energy efficiency policy.

Now, let’s see in which sector we can reduce use of energy and some policy to motivate the people.

Industrial Sector

Major energy use in industrial sector and there are inductive and non inductive load. In our country, there are no major rules or not applied properly the rules for machine use. Like many industry using motor and sometimes those motor are not efficient at all and may be it will be recondition or old enough to be an efficient motor. Most of the inductive load do not have soft starter. Even in general use of water pump, there are no standard efficient level for selecting pump. Therefore people using 2500 tk water pump and that same 1 hp pump, in good branded one will be 7500 or higher. But people choose low price one which will destroy power and less efficient.

Air condition

Now on days, we are used to use of these products. It is inductive load and consumed good amount of energy. Nobody cares to reduce the temp level or efficient products. Recently, at the same price, many manufacture offering 50% less power but same BTU because they are using DC motor. Therefore high tax, high electricity unit price where higher then 3-5 kilo residential load needed. But it may not be possible due to political and public emotion purpose. But still there are no substitutes to make energy expensive then people will careful to use of energy.

Lighting purpose

We came to new energy saving age and using cfl bulb or tube. It will save energy sure but it cause heavy damage in environmental. Every cfl contain mercury and emit UV. UV is harmful for our skin and mercury is highly radioactive poison. When any bulb damage in our room, we have to keep vacant that room and open door, windows because of mercury vapor. After that we send it outside or sale. If it is goes to river, soil it will damage the water and its poison circle will start. It affect drinking water, fish and we take water or fish and cause cancer, unborn child defect, etc. Some tube light THD level also too high which decrease gird performance. we can use LED light in this purpose. It is environmental friendly, long life (50000 Hrs where cfl is 3000 to 5000 hrs), very less energy consume even one third comparing cfl. As it is still expensive, we can use certified cfl and rules and regulation for recycling cfl. Another thing is still now; customs do not have HS code or tax structure for led light, bulb or tube. Led light must have duty/ tax free access.

BTS for mobile operator

 Bangladesh has rapidly expanding mobile uses and according to that base transmission station also need. Now, 25000 over BTS running and more 7000 or more coming within 2 years. For mobile company, energy unit rate must have different category (high). Every BTS they use 2 pc 1 ton air conditioner which run round the clock. Now, if we calculate everyday 18 hrs air condition running this means 32.4 kilo only air condition. 32.4 times 25000 = 810000 kilo everyday 810 megawatt everyday.

 Future plan

In Bangladesh ,crisis in power sector becomes one of the major problems .some recent steps and a strong and clear forecasting is needed to overcome that problems .power sector is always been one of the major priority for Bangladesh government . To overcome the problems, a large and clear future plan is been taken by Bangladesh government.

It is estimated that power demand of our country will be almost double in upcoming 5 years.

Energy advisors press meet produced some important figures as can be seen below-

Table  Estimated Demand [ MW Per Day ] Supply Gap

Year 2010 2011 2012 2013 2014 2015 2016
Max Demand 6454 6765 7518 8349 9268 10283 11405
New Generation

Public Sector

255 851 838 1040 1270 450 1500
New Generation Private Sector 520 1343 1319 1134 1053 1900 1300
Power Import 500      
Capacity Retired   58 83 161 1292 128 1033
Generation Capacity 5936 8042 10116 12629 13660 15882 17649
NET 5499 7720 9 12124 13114 15247 16543
Dependable Capacity[Dec2010] 4331 5945 7575 9578 10491 12197 13554
Maximum  supply Shortage In Summer 2123 520 57 + 1229 + 1223 + 1914 +2149
               

 

yearly increasing demand ( in MW )

Figure  yearly increasing demand ( in MW )

Bangladesh government will increase power generation to reach their goal of ‘load shedding free Bangladesh ” , for that a large number of power new plant will be installed in next 5 years.

Some of the future projects given below –

Power plant in Sirajgonj

 Prime Minister of Bangladesh Sheikh Hasina recently (4th april,2011) laid foundation stone of 150 megawatt peaking power plant at Saidabad in the district. Hasina also inaugurated expansion works of the Saidabad-Enayetpur road and reopened the much-expected Sirajganj National Jute Mills previously known as Qaumi Jute Mills.

Chittagong power to get Canadian help

A Canadian company has expressed its interest in generating electricity from the domestic waste produced by the Chittagong city people every day. CEO of Canadian Company Technology Not Theory (TNT) Steve Smith expressed the interest to the Mayor of CCC in meeting with the mayor recently. The project is fully environment friendly and pollution free, Smith pointed.

Power Grid Company installing substation

The Power Grid Company of Bangladesh recently signed an agreement with German company Siemens to install a substation that would link about 30 kilometers grid interconnection between Bangladesh and India to import 500MW electricity from 2012.

BGMEA to set up power plant

Bangladesh Garment Manufacturers and Exporters Association (BGMEA), apex body of the readymade garment (RMG) industry, will shortly begin a technical assessment on setting up small, area-based power plants. The BGMEA move came in response to Prime Minister (PM) Sheikh Hasina’s call recently to set up such power plants to meet industry demand.

North West power generation company to install 810 MW power plant

North-West Power Generation Company (NWPGCO), a newly formed state-owned power company, is set to install 810 MW power project in the northwestern part of the country to address nagging power crisis of the area.

Bangladesh and India power transmission deal

Bangladesh and India signed a power transmission agreement for electricity to be imported to energy-starved Bangladesh.

Initially, 250 megawatts of power would be available to Bangladesh from India, with transmission to start in 2012.

Under the deal, state-owned Power Grid Corporation of India Ltd. will invest and construct 50 miles of transmission line, which it will own, operate and maintain. PGCIL will recover the construction costs under a fixed rate over 35 years.

While the agreement is limited to importing 500 megawatts of electricity from India, state-owned Bangladesh Power Development Board Chairman Alamgir Kabir said that more interconnections might be built in the future with Nepal, Bhutan and Myanmar to ensure greater energy security

Bangladesh and Russia deal

In May 2011, Bangladesh and Russia signed a framework agreement for Bangladesh’s first nuclear plant, expected to produce at least 2,000 megawatts of electricity by 2020. Bangladesh aims to have nuclear energy account for 10 percent of its total power generation by that time.

Some other Future power plants

Govern take a plan to produce  4500MW more power by installing some new power plantds. List of the plants and their capacity is given below –

Table Future power plant

Location Fuel Capacity Implementation
Nabiganj , Bibiyana Natural Gas 450 Combined Cycle Plant 2013
Siarjgonj Natural Gas 450 Combined Cycle Plant 2013
Meghnaghat unit 2   & 3 Natural Gas 2 unit each 450 Combined Cycle Plant 2013
Bheramara Natural Gas 450 Combined Cycle Plant 2014
Horipoor Natural Gas 300 MW Combined Cycle 2014
Chanddpoor Dual Fuel 150 MW CCP 2014
Khulna Dual Fuel 250 MW CCP 2014
Siddhiragnj Natural Gas 2×150 = 300 MW Peaking Plants 2014
Phulbari Coal Fired using Clean Coal Technology 2×500= 1000MW 2014
Mongla Coal Fired using Clean Coal Technology 500MW 2014
Total 4750MW 2014

Government to set up coal based power plant

According to Power System Master Plan (PSMP) the government has planned to set up eight new power plants with 4,000MW capacity by the year 2015. The government has primarily identified 13 places to install coal based power plants and now trying to install four plants at Khulna, Mongla, Meghnaghat and Chittagong areas, Taking into consideration the fast-growing demand of power consumption amid scanty supply, the PSMP has also taken up a mega-plan for producing about 20500MW additional electricity in 20 years from 2005 to 2025 by setting up 30 new plants. Bangladesh government needs US dollar six billion to implement coal power projects to meet the increased demand of electricity in the country. Of the plants, eight or more will be installed in the country’s north and northeastern regions where demand for electricity is increasing at a galloping rate of seven percent, in order to achieve this goal the development of Barapukuria and Phulbari should be more intensive.

Natural Gas

Natural gas is a major source of electricity generation through the use of gas turbines and steam turbines. Most grid peaking power plants and some off-grid engine-generators use natural gas. Natural gas burns more cleanly than other fuels, such as oil and coal, and produces less carbon dioxide per unit of energy released. For an equivalent amount of heat, burning natural gas produces about 30% less carbon-dioxide than burning petroleum and about 45% less than burning coal.

In Bangladesh natural gas is most important indigenous source of energy that accounts for 75% of the commercial energy of the country. About 89% of the electricity generated in the country comes from gas fired power plants. Installed capacity of Electricity generation by gas is steam-2638 MW (45.31%), Gas turbines-1466 MW (25.18%), combined cycle-1263 MW (21.69%). So far in Bangladesh 23 gas fields have been discovered with the rate of success ratio is 3.1:1 of which two of the gas fields are located in offshore area. Gas is produced from 17 gas fields (79 gas wells). To reduce the dependency on natural gas, alternative energy resource must be explored. Average daily gas production capacity is about 2000 mmcfd of which International Oil Companies (IOC) produce 1040 mmcfd and State Owned Companies (SOC) produce 960 mmcfd. At present the daily approximate projected gas demand throughout the country is 2500 MMCFD. The demand is increasing day by day. Energy and Mineral Resources Division (EMRD) has already undertaken an array of short, medium, fast track and long term plans to increase gas production to overcome prevailing gas shortage. After completion of these plans production capacity is expected to increase to about 2353 MMCFD gas by December 2015. To increase the gas production more programs will be taken in near future.

Oil

Oil is another source of electricity generation. Bangladesh is not a oil enriched country. Diesel, Furnace oil (HFO) are generally used in Bangladesh to produce electricity. Here 226 MW (3.87%) electricity generates from Diesel.  To meet the total demand of commercial energy, Bangladesh imports annually about 1.3 million metric Tons of crude oil. In addition to this, another 2.7 million metric Tons (approx) of refined petroleum products per annum is imported. Condensate is mixed with crude oil. Major consumer of liquid fuel is transport sector followed by agriculture, industry and commercial sector which is mostly met by imported liquid fuel. Eastern Refinery Limited (ERL), a subsidiary company of Bangladesh Petroleum Corporation (BPC), is capable of processing 1.3 million metric Tons of crude oil per year.

Oil was tested in two of the gas fields (Sylhet and Kailashtila). Crude oil, the liquid form of hydrocarbon, has been discovered in commercial quantity only in the Haripur oil field in Sylhet. The oil field has an estimated in-place oil reserve of about 10 million barrels, with a recoverable reserve of about 6 million barrels. The oil field produced 0.56 million barrels of oil in six years. Khulna Power Company Limited is one of the main oil based power station of Bangladesh. Furnace oil is its main fuel.

Renewable Energy

Renewable energy is the energy which comes from natural resources such as sunlight, wind, rain, tides, water, and geothermal heat, which are renewable (naturally replenished). In 2008, about 19% of global final energy consumption came from renewable, with 13% coming from traditional Biomass, which is mainly used for heating, and 3.2% from hydroelectricity. New renewable (small hydro, modern biomass, wind, solar, geothermal, and bio fuels) accounted for another 2.7% and are growing very rapidly. The share of renewable in electricity generation is around 18%, with 15% of global electricity coming from hydroelectricity and 3% from new renewable.

Hydroelectricity

Karnafuli Hydro Power Station the only hydropower plant in the country is located at kaptai, about 50 km from the port city of chittagong. This plant was constructed in 1962 as part of the ‘Karnafuli Multipurpose Project’, and is one of the biggest water resources development project of Bangladesh. After being commissioned in 1962, the plant could feed the national grid with 80 MW of electricity. In later years, the generation capacity was increased in two phases to a total of 230 MW which is 3.95% of total generated electricity. The plant not only plays an important role in meeting the power demand of the country but is also vital as a flood management installation for the areas downstream.

In future hydroelectricity will be a probable sector of power generation of Bangladesh. Possibility of installing mini and micro level hydro-electric power plant in the hilly areas of Bangladesh would be explored.

Solar Energy 

Solar energy is the energy derived from the sun through the form of solar radiation. Potential of solar energy is good in Bangladesh. Bangladesh is a poor country and it’s a huge cost to established a power plant. Consequently, the only option that is open to Bangladesh at the moment is renewable energy such as solar and hydro-electric. Particularly solar energy is sufficiently abundant in Bangladesh and can fruitfully be harnessed. But due to its higher cost of equipment it has to go a long way to become commercially viable. However, in remote areas of Bangladesh it is gradually becoming popular and government has undertaken lot of scheme to subsidize on it. Presently there are about 2, 64,000 solar panels installed throughout the country.

Now, more than 3 lakh houses (.3m) of 465 upazilla of all the districts and 16 islands are getting the light of solar energy. The beneficiaries of this system are about 30 lacks (3m). 44 megawatt electricity is produced everyday from the solar projects in Bangladesh. In future Bangladesh Government wants to produce 20% of electricity from the solar energy.

Bio-Gas 

Biogas may be the most promising renewable energy resource. Presently there are about 50,000 households and village-level biogas plants in place throughout the country. There is a huge potential for expansion in rural areas.

There is prospect of producing 1,000MW electricity from Biogas and if the opportunity is utilized the growing shortage of electricity could be solved in this power-starved country. The government agency Infrastructure Development Company Limited sources said Bangladesh has 215,000 poultry farms and 15,000 cattle farms. Establishing biogas plants in these farms, electricity could be generated. So far 35,000 biogas plants have been established across the country and these plants are producing gas, which is being used for cooking purposes in the rural areas. At present 33 lack squire feet biogas is being produced in the country daily. The Government agency said they got eight core tons of cow dung in 2004.With this cow dung, 30 lack biogas plants could be run. Government has a target to establishing 60,000 biogas plants by 2012.

Wind Power

Wind power harnesses the power of the wind to propel the blades of wind turbines. 31 At the end of 2009, worldwide wind farm capacity was 157,900 MW, representing an increase of percent during the year. Germany, Spain, Denmark, Portugal, United States are leading wind power producer country.

Bangladesh generates a very small amount of electricity from this sector. Windmills are with capacity of 2 MW in operation in the coastal area of Bangladesh. The possibly of this type of power generation is low.

Nuclear Energy

Nuclear power station use nuclear fission to generate energy by the reaction of uranium-235 inside a nuclear reactor. Now a day it’s one of the major sources of electricity. At present in Bangladesh electricity generates from nuclear energy is 0%. Recently we signed an agreement with Russia to install our first nuclear plant at Rooppur in Pabna. The construction cost is initially being put at between US$1.5 billion and $2 billion in the final agreement The Rooppur nuclear power plant (RNPP) will eventually generate around 2,000 megawatts (MW) of electricity, with each of two proposed reactors having a capacity to generate 1,000 MW.

Coal as a source of energy

Coal is a valuable and plentiful natural global resource. Coal, a fossil fuel, is the largest source of energy for the generation of electricity, worldwide. Coal plays a vital role in electricity generation worldwide. Coal-fired power plants currently fuel 41% of global electricity.

Besides natural gas, Bangladesh has significant coal reserve. Coal reserves of about 3.3 billion tons comprising 5 deposits at depths of 118-1158 meters have been discovered so far in the north-western part of Bangladesh. The name of these deposits are-Barapukuria, Phulbari and Dighipara coal field in Dinajpur district, Khalashpir in Rangpur district and Jamalganj in Joypurhat district. Out of which 4 deposits (118-509 meters) are extractable at present. As an alternative fuel to natural gas, coal can be extensively used. The depth of Jamalganj coal deposit is 640-1158 meter with 1053 Million Tones in-situ coal reserve where production may not be viable by present day’s technology due to the depth of the deposits. Possibilities of extraction of Coal Bed Methane (CBM) need to be explored from this coal deposits. Government is actively reviewing law to be applicable for Exploration and Production of Coal Bed Methane. So far, only Barapukuria coal field is under production. Dinajpur Barapukuria coal fired power plant is our first coal based power plant which capacity is 250MW. Then some small power plant was made. Bangladesh has a bright future in coal based power generation if we remove the obstacle of this sector.

Coal fields of Bangladesh

Bangladesh is sleeping on coal mine bed located in the northern districts of Rangpur and Dinajpur, while facing a mounting energy crisis and relies on natural gas as the main source of energy, which is depleting at geometrical progression. In contrast, Bangladesh has proven reserve of 3.0 billion tonnes of low sulphur, low ash, high caloric value bituminous coal in five discovered coal mines – Phulbari, Barapukuria, Jamalganj, Dighipara and Khalsapir.

Bangladesh has 15 tcf (trillion cubic feet) of proven reserve of natural gas; the remaining 6 tcf reserve of natural gas may run out by 2015, if no discovery is made soon.  As against this, the coal reserves in five fields of Bangladesh are estimated at 3.0 billion tonnes equivalent to 67 tcf of gas, which can conveniently serve the energy needs of Bangladesh for 50 years.

Table Coal Reserves in Bangladesh

The depth of the discovered fields ranges between 119 – 506 metres and 150 – 240 metres in Barapukuria and Phulbari respectively. The depth of the largest field at Jamalganj ranges from 900 – 1000 metres.  The area covered by coal fields is rather limited and is about 70 – 80 square kilometres. A total of 1.73 million tonnes of coal has been extracted by underground method from Barapukuria up to December 2008. The present value of coal per tonne in international market is for steam coal US$ 65-115, coking coal US$ 250, metallurgic coke coal US$ 525. The total value of coal will be more than US$ 500 billion.

Barapukuria Coal Field

The Barapukuria coalfield is located at the Parbatipur Upazila of Dinajpur district, at a distance of about 50 km southeast of Dinajpur town. The coalfield has a proved area of about 5.25sq km. The estimated resource of the coalfield is 390 MT.

The government decided to establish an underground coal mine at Barapukuria. In 1993, the government entered into a contract with the Chinese government for technical and financial assistances for establishing the mine. The mine construction by the Chinese contractor started in 1996 and was originally scheduled to be completed by 2001. But this was delayed and finally commercial production started from September 2005.

However, the underground mining operation in Barapukuria has been facing many difficulties from the beginning of its development stage. In 1998, a sudden water inrush flooded the mine and forced to suspend mine development works for two years. The revised mine design reduced both mineable reserve and mine life. In fact, the existing geologic setup: the thick overlying water bearing Upper Dupi Tila  sequence, high jointed thick coal seam (36m) with numerous faults and joints made the situation difficult for smooth economic operation of the mine. The unfavorable underground mining environment with high temperature, very high humidity, and unidentified sources of hot water, spontaneous combustion and lethal gas emission made the situation dangerous and unhygienic for the mine workers. An incident of spontaneous combustion and emission of poisonous carbon monoxide gas led to suspend operation and sealing off a mining face with one of its longwall systems.

Phulbari Coal Field

The Phulbari coalfield was discovered in 1997 by BHP Minerals. The Phulbari coalfield is located about 10 km south of the Barapukuria coal field and in the vicinity of Phulbari township. The coalfield is conveniently located close to the new dual gauge rail line.

Subsequent to the discovery of Phulbari coalfield, BHP Minerals decided to withdraw from Bangladesh and transferred its Contract and existing licenses to another mining company Asia Energy Corporation (Bangladesh) Pty Ltd with the approval of the Government. In this regard, an Assignment Agreement was signed on 11 February 1998.  The pre feasibility study carried out in 2000 confirmed the economic viability of large scale open pit mine in Phulbari Basin. Asia Energy had undertaken a detailed feasibility study including extensive geological, hydro geological, environmental and social studies during the period 2004-05 and established an internationally accepted (JORC Standard) resource of 572 Mt of high quality thermal and metallurgical coal.

The mining area in the Phulbari Basin covers an area of eight kilometers (north-south) by three kilometers (east-west) with coal seam(s) varying between 15-70 meters thick at some 150-270 meters beneath the surface, with average combined thickness of 38 meters. The Phulbari coal is high volatile bituminous coal. It has low ash (average 15%) and low sulfur content (<1%) and therefore suitable for both power generation and for producing semi-soft coking coal.

Asia Energy submitted Scheme of Development on October 2005 to the Government with a plan to develop the Phulbari coal deposit by the open cut mining method. In 5 years three governments failed to either approve the scheme or reject it with technical justifications. Coal resources of  Phulbari remains unexplored.

The mine is estimated to produce 15 million tonnes of coal per year over 35 years of mine life. Asia Energy has also submitted proposal to setup up to 1000 MW mine mouth coal-fired power plant based on Phulbari coal. In addition to coal, the open pit mining method will allow economic extraction of other co-products like kaolin, clay, glass sand rock and aggregate, which are in high demand.

Jamalganj Coal Field

The Jamalganj coalfield is located in Joypurhat district in the vicinity of Jamalganj town and to the west of the north-south broad-gauge railway line. The coalfield was discovered in 1962 by the Geological Survey (of the then Pakistan) under the UN sponsored coal exploration program. Under the program 10 wells were drilled in the Jamaganj-Paharpur area of Joypurhat district. Coal seams were encountered in 9 wells within depth range of 640 to 1158 meter below the surface in Permian Gondwana rocks. The 9 bore holes that penetrated the coal seams are spread over an area having a maximum east-west distance of 12.5 km and a north-south distance of 4.8 km. The coal field has an estimated resource of 1053 Mt bituminous coal.

Following the discovery of the coalfield, several international consultants, were invited to conduct mine feasibility study. These include Fried Krupp Rohstoff (1966), Polwell Daffryn Technical Services (1969) and Robertson Research International (1976). Although rated technically feasible, the economic feasibility of mining Jamalganj coal could not be shown because of the unfavorable depth of coal seams. Eventually, the idea of mining coal from Jamalganj field was abandoned when a large coal deposit was discovered at much shallower depth of about 120 meter below the surface at Barapukuria basin in Dinajpur district. However, developing coal bed methane (CBM) in the Jamalganj coalfield has since been considered a potentially viable option.

 Khalashpir Coal Field

Khalashpir coalfield is located in Pirganj Upazila of Rangpur district, about 13 km west of Pirganj town. Khalashpir coalfield was discovered in 1989 by the Geological Survey of Bangladesh. The coalfield was delineated and defined on the basis of the four drill holes done during 1989-90. The coal was encountered at depths ranging from 257 to 482 meter below the surface in a Gondwana basin. Occurrence of coal has been proved in an area of about 2.52 sq km and a further extension of the basin is estimated. The Khalashpir coalfield has an estimated resource varying from 143-450 Mt.

Dighipara Coal Field

Dighipara coalfield is located in Dighupara Upazila of Rangpur district,  Dighipara coalfield was discovered in 1995 by the Geological Survey of Bangladesh. The coalfield was delineated and defined on the basis of the five drill holes. The coal was encountered at depths is 327meter below the surface. The Dighipara coalfield has an estimated resource of 200 Mt.

Coal mining methods

However, we failed to explore and exploit the natural resources to utilize these for economic development. We have miserably failed to cope up with the increasing energy demand of the country. We have age-old mining policy, mining act and mining regulations. We do not have any exploration and utilization strategy of gas reserve. We are yet to have a coal policy finalized. The Bureau of Mineral Development issued a license to BHP(Broken Hill Proprietary Company), Australia in 1994 for exploration of Phulbari Mine. The license was transferred to Asia Energy in 1997. Bangladesh media quoting responsible sources stated that Asia Energy is yet to obtain mining license. However, the mining could not proceed due to alleged lack of transparency in award of the license and unrest in the area triggered by a motivated group of left leaning intellectuals. The agitations lead to death of 6 protesters in police and paramilitary troops firing.Coal mining at Phulbari and other coal fields now hinges on the Coal Policy under consideration of the government. The Coal Policy is pending for quite some time due to disagreements on some issues, namely,

(a) Open pit versus underground mining

(b) Social environmental impact management

(c) Royalty etc. Government engaged committee having line professionals

Selection of mining methods depend on several things – geology of mine area, terrain condition, topography, soil condition and nature, depth, thickness and nature of coal seam, surface and subsurface soil condition.

One of the major challenges the energy sector is facing is to find out ways how to economically exploit its substantial high quality coal reserve .The predominantly mono fuel –Natural Gas dependent power generation is in limbo. The proven gas resource is widely believed to be exhausted in not too distant future. For confusion and panic set in by inexperienced ill motivated theoreticians and absence of strong political commitment government could not take decision of appropriate mining strategy to economically exploit coal resource. The deficit is widening. The ensuing summer will witness massive load shedding.

The just installed democratic government will face serious embarrassment for failures of incompetent last political and immediately past Care Taker Government. Of the 5 discovered ca coal mines the Jamalgonj coal is at greater depth which cannot be mined in traditional mining methods. Coal at Khalaspeer and Dighipara are also at relatively greater depth. Barapukuria and Phulbari coal are at relative shallower depth. The geology makes these ideal for open pit surface mining which is in practice in the following countries now.

Bangladesh which has limited capacity to purchase petroleum products from volatile world oil market cannot continue to keep its fortune buried underground forever. It cannot also remain confused triggered from myths and ill motivated propaganda of a vested group. The disadvantage is most of our innocent people as well as policy makers do not have much knowledge of mining. There is no scope of learning mining technology in Bangladesh also. During Pakistan days sons of well to do persons who could not get admissions in Ahshanullah Engineering College used to go to Lahore to study mining. This group of mining engineers worked in Gas sector in absence of mining activities in Bangladesh. They could neither become good miners nor good gas engineers. Rather for their control other professionals got frustrated and many left gas sectors. Many mining engineers created controversy in Gas Sector also. There were few outstanding mining engineers as well. But no all of them retired. But unfortunately none of them were included in drafting coal policy.

Bangladesh let a Chinese company start underground mining at Barapukuria. Many mining experts felt the existing geology can never make underground mining technically viable or economically feasible there. Still a vested group of BNP government from 1991-96 allowed to start Barapukuria mining under suppliers credit. Experts now feel that there were several juggleries in the project approval process. It now appears that proper risk assessments of Bapaukuria mining were not done. The possible and probable subsidence impacts were not anticipated and no actions were foreseen to address those impacts. Now after a more that one and a half decade of trouble tone mining with several major set backs at various stage mine subsidence impacts are now visible which may puts future of mining uncertain.

BHP Billiton, the leading Mining Company of the world was given mining lease at Phulabri where very thick seam bituminous coal is lying at shallow depth. At some stage of survey and assessment it transferred lease to Asia Energy Corporation. (AEC) UK.AEC carried out extensive survey, carried out some exploratory drillings, completed extensive Environment Impact Assessment studies. Then it submitted a comprehensive study to Government of Bangladesh in January 2005 after meeting all the contractual requirements. The development plan included surface mining methods. It included proper relocation and rehabilitation plan of the affected people. Bangladesh was due to approve to reject the development plan within the contractual time frame.

He engaged a  so called Energy Expert   to review the Phulbari mining matters. This gentleman stepped out of his assigned responsibility and agitated the people of Phulbari over AEC proposed open pit mining.BNP government should have done community consultations to pacify the situation. But a very arrogant Mahmud let situation go out of control .The local agitation led to unfortunate situation when some innocent misguided local people were killed.

The local situation was to be controlled by signing a compromise agreement by Mayor Rajshahi and MP. This irrelevant piece of paper was signed with a legally unrecognizable organisation. Now based on this the agitators are demanding to scrap AEC contract , banning open pit mining etc, etc & etc. Any sensible person will realize that such an agreement has no legal bearing in dealing with a contract signed between a sovereign government and an international company.

Any contract includes a termination clause. It requires one party to establish default of the other party with evidences. It also requires the party notifying default of the other party to give them to defend its position. If Bangladesh ventures to terminate the AEC contract then this will obviously go to arbitration. Bangladesh will invariably loose and will have to pay huge compensation.

Open pit mining
Open pit mining as defined in open encyclopaedia states, “Open pit mining, also known as opencast mining, open –cut mining, and strip mining, refers to a method of extracting rock or minerals from the earth by their removal from an open pit or borrow. Open –pit mines are used when deposits of commercially useful minerals or rock are found near the surfaces, that is where the overburden (surface material covering the valuable deposit) is relatively thin or the material of interest is structurally unsuitable for tunneling .For minerals that occur deep below the surface –where overburden is thick or minerals occurs as veins in hard rock – underground mining methods extract the valuable material.

Open pit mines are typically enlarged until either the mineral resources are exhausted, or an increasing ratio of overburden to ore makes further mining uneconomic. When this occurs, the exhausted mines are sometimes converted to landfills for disposal of solid wastes. However some form of water control is usually required to keep the mine pit from becoming a lake.

Open Cut mines are dug on benches, which describe vertical levels of the hole. These benches are usually on four meter to sixty meter intervals, depending on the size of the machinery that is being used. Many quarries do not use benches, as they are usually shallow.

Most walls of the pit are generally dug on an angle less than vertical, to prevent and minimize damage and danger from rock falls. This depends on how weathered the rocks are, and the type of rock, and also how many structural weaknesses occur within the rocks, such as a fault, shears, joints or foliations.

The walls are stepped. The inclined section of the wall is known as the batter, and the flat part of the step is known as the bench or perm. The steps in the walls help prevent rock falls continuing down the entire face of the wall. In some instances additional ground support is required and rock bolts, cable bolts and concrete are used. De-watering bores may be used to relieve water pressure by drilling horizontally into the wall, which is often enough to cause failures in the wall by itself.A haul road is situated at the side of the pit, forming a ramp up which trucks can drive, carrying ore and waste rock.

Waste rock is piled up at the surface, near the edge of the open cut. This is known as the waste dump. The waste dump is also tiered and stepped, to minimize degradation. Ore which has been processed is known as tailings, and is generally a slurry. This is pumped to a tailings dam or settling pond, where the water evaporates. Tailings dams can often be toxic due to the presence of unextracted sulfide minerals, some forms of toxic minerals in the gangue, and often cyanide which is used to treat gold ore via the cyanide leach process.
After mining finishes, the mine area must undergo rehabilitation. Waste dumps are contoured to flatten them out, to further stabilize them. If the ore contains sulfides it is usually covered with a layer of clay to prevent access of rain and oxygen from the air, which can oxidize the sulfides to produce sulfuric acid, a phenomenon known as acid mine drainage. This is then generally covered with soil, and vegetation is planted to help consolidate the material. Eventually this layer will erode, but it is generally hoped that the rate of leaching or acid will be slowed by the cover such that the environment can handle the load of acid and associated heavy metals. There are no long term studies on the success of these covers due to the relatively short time in which large scale open pit mining has existed. It may take hundreds to thousands of years for some waste dumps to become “acid neutral” and stop leaching to the environment. The dumps are usually fenced off to prevent livestock denuding them of vegetation. The open pit is then surrounded with a fence, to prevent access, and it generally eventually fills up with ground water. In arid areas it may not fill due to the deep groundwater levels.

Environmentalists in all countries oppose mining; oppose burning of coal. But nowhere they can ride over policy makers to keep mining suspended for years when the energy security is compromised by not adopting economic mining method as is the case in Bangladesh. In this context it will not be out of place to discuss almost a similar situation in Malaysia – a country having almost similar geographical, geological and environmental situation like Bangladesh.

Underground Coal mining

Underground coal gasification (UCG) is an industrial process, which converts coal into product gas. UCG is an in-situ gasification process carried out in non-mined coal seams using injection of oxidants, and bringing the product gas to surface through production wells drilled from the surface. The product gas could to be used as a chemical feedstock or as fuel for power generation. The technique can be applied to resources that are otherwise unprofitable or technically complicated to extract by traditional mining methods and it also offers an alternative to conventional coal mining methods for some resources.

Underground coal gasification converts coal to gas while still in the coal seam (in-situ). Gas is produced and extracted through wells drilled into the un-mined coal seam. Injection wells are used to supply the oxidants (air, oxygen, or steam) to ignite and fuel the underground combustion process. Separate production wells are used to bring the product gas to surface. The high pressure combustion is conducted at temperature of 700–900 °C (1,290–1,650 °F), but it may reach up to 1,500 °C (2,730 °F). The process decomposes coal and generates carbon dioxide (CO2), hydrogen (ḥ), carbon monoxide (CO) and small quantities of methane (CH4) and hydrogen sulfide(H2S). As the coal face burns and the immediate area is depleted, the oxidants injected are controlled by the operator

As coal varies considerably in its resistance to flow, depending on its age, composition and geological history, the natural permeability of the coal to transport the gas is generally not adequate. For high pressure break-up of the coal, hydro-fracturing, electric-linkage, and reverse combustion may be used in varying degrees.

Two methods are commercially available. One uses vertical wells and a method of reverse combustion to open internal pathways in the coal. The process was used in the Soviet Union and was later modified by Ergo Energy. It was tested in Chinchilla site in 1998–2003. Livermore developed another method that creates dedicated inseam boreholes, using drilling and completion technology adapted from oil and gas production. It has a movable injection point known as CRIP (controlled retraction injection point) and generally uses oxygen or enriched air for gasification.

According to the Commonwealth Scientific and Industrial Research Organisation the following coal seam characteristics are most suitable for the underground coal gasification:

  • Depth of 100–600 meters (330–2,000 ft)
  • Thickness more than 5 meters (16 ft)
  • Ash content less than 60%
  • Minimal discontinuities

There are a number of site specific technical factors which are important to the process. Coals with wide range of properties can be utilized, items of significance include

  • The geology of the coal seam must be continuous and preferably thicker than three meters.
  • The overburden should be more than 100m thick, relatively impermeable and with reasonable strength above the coal seam.
  • The water table preferably should be within 20m or from the ground surface to provide cavity water pressure to balance the oxidant injection pressure and limit product gas leak

While each of the above each of the above item is individually important, it is over an appraisal of many technical aspects of the site that govern sits suitability for development. Commercial matters like size of coal reserve and the market for the produced gas are also critical for the development of a project at a particular site.

Comparison between the methods

Bangladeshi policy makers may carry out some research on UCG .It is not very difficult to locate the real pioneers of UCG. Whether or not UCG can be applicable in any Bangladesh coalmine is subjected to extensive feasibility study by truly professional company of proven track record. It is too early to comment on suitability of Bangladeshi coal mines for UCG. Let Government find the most appropriate company from among handful companies involved in UCG in Australia, South Africa and Pakistan. Let there be authentic feasibility study. Minor companies can tell stories but they can do nothing practically. UCG is a highly sophisticated and sensitive technology. One of the early generation UCG pioneer Russian Canadian Mr Blinderman is now living in Canada. Bangladesh must not try amateur attempt to extract UCG from its mines as they did with Barapukuria coalmine pursuing inappropriate underground mining. If any of our mine qualify for UCG that must be established by experts of proven technology. But this must not bring any impediments to mining of coal from reserves which are suitable for traditional mining.

Professionals already mentioned time and again about applicability of Strip Mining [Open Pit] at Barapukuria and Phulbari. Many thinks a combination of Open pit and underground mining can work in Khalaspeer and Dighipara. Unfortunately detail feasibility study could only be carried out at Phulbari by internationally accredited consultants. . Even then policy makers could not take decision on Phulbari after 5 years of receipt of professional mining proposal. The in appropriate mining at Barapukuria has triggered disaster. The most suitable mine for strip mining is an opportunity lost. Barapukuria is proved to be a failed project yet triggered massive subsidence at very early stage of mining. It experienced all impacts of an failed underground long wall mining .Luckily there has been not many causalities so far.

For example:
The existence of the open-pit mine, in Mukah have proven to be a blessing to the Iban community because:
They benefitted directly from the land compensation given by the said mining company for rights to mine on their land. Evidence can be seen from the fact that many of the long houses locating on the Mukah Coalfield have utilised the money to upgrade their longhouses and to purchase other necessities to enjoy comfort of modern living.
Through employment received from the said mining company , the community can supplement their shifting cultivation income by the more consistent monthly wages earned working as mining crew.
A As they are expose to the usage of modern equipment , they are able to accelerate their assimilation into modern world of 21st century and this will augur well for the Iban community in general specially for the younger generation.

The open cut mining project in Mukah have brought substantial benefits to the local community and the State of Srawak, through such contribution as Royalties to the sate for extraction of coal, a better standard of living for the local community through direct and indirect employment and a general increase in business for the local businesses in Mukah Division.

There seems to be lot of similarities of Mukah region of Malaysia with our Phulbari, Barapukuria region. We can definitely try to learn lessons and try to replicate the good works. Malaysia is not very far from Bangladesh. Government can organize sending its officials, mining professionals, environmentalists to eye witness the mining activities, and management of social and environmental impacts of open pit mining. It is not a rocket science. We talk about digital Bangladesh. We still do not know what open pit mining is. Silly and ridiculous to keep our fortune buried while nation continues to suffer from serious energy crisis

COAL IN PROUCTION OF ELECTRICITY

Modern life is unimaginable without electricity. It lights houses, buildings, streets, provides domestic and industrial heat, and powers most equipment used in homes, offices and machinery in factories. Improving access to electricity worldwide is critical to alleviating poverty.

How is Coal Converted to Electricity

Steam coal also known as thermal coal is used in power stations to generate electricity.

Coal is first milled to a fine powder which increases the surface area and allows it to burn more quickly. In these pulverized coal combustion (PCC) systems the powdered coal is blown into the combustion chamber of a boiler where it is burnt at high temperature (see diagram below). The hot gases and heat energy produced converts water – in tubes lining the boiler – into steam.

The high pressure steam is passed into a turbine containing thousands of propeller-like blades. The steam pushes these blades causing the turbine shaft to rotate at high speed. A generator is mounted at one end of the turbine shaft and consists of carefully wound wire coils. Electricity is generated when these are rapidly rotated in a strong magnetic field. After passing through the turbine the steam is condensed and returned to the boiler to be heated once again.

The electricity generated is transformed into the higher voltages (up to 400,000 volts) used for economic efficient transmission via power line grids. When it nears the point of consumption, such as our homes the electricity is transformed down to the safer 100-250 voltage systems used in the domestic market.

 Electricity sector in Bangladesh

Bangladesh’s energy infrastructure is quite small insufficient and poorly managed. The per capita energy consumption in Bangladesh is one of the lowest (136 kWH) in the world. Noncommercial energy sources such as wood, animal wastes, and crop residues are estimated to account for over half of the country’s energy consumption. Bangladesh has small reserves of oil and coal but very large natural gas resources. Commercial energy consumption is mostly natural gas (around 66%) followed by oil, hydropower and coal.

Electricity is the major source of power for country’s most of the economic activities. Bangladesh’s installed electric generation capacity was 4.7 GW in 2009 only three-fourth of which is considered to be ‘available’. Only 40% of the population has access to electricity with a per capita availability of 136 kWh per annum. Problems in the Bangladesh’s electric power sector include corruption in administration, high system losses, delays in completion of new plants, low plant efficiencies, erratic power supply, electricity theft, blackouts, and shortages of funds for power plant maintenance. Overall the country’s generation plants have been unable to meet system demand over the past decade.

In generating and distributing electricity the failure to adequately manage the load leads to extensive load shedding which results in severe disruption in the industrial production and other economic activities. A recent survey reveals that power outages result in a loss of industrial output worth $1 billion a year which reduces the GDP growth by about half a percentage point in Bangladesh. A major hurdle in efficiently delivering power is caused by the inefficient distribution system. It is estimated that the total transmission and distribution losses in Bangladesh amount to one-third of the total generation the value of which is equal to US $247 million per year.

Developing Thar Coal  In Bangladesh

Coal is the cheapest source of energy consumed the world over playing a pivotal role in the generation of power for the smooth operation of industries. Thar coal is said to be one of the largest coal reserves in the world situated in Tharparkar Sindh. Coal is the most important source used for generating electricity in most of the developed and developing countries.

The authentic statistics of the World Coal Institute, London published in 2006 say that the share of the coal in the production of power in the United States is about 52.2 per cent while China produces 77.5 per cent of its total electricity by using coal.

The share of coal in the production of electricity is 92.2 per cent in South Africa. Our closest neighbor (India) meets approximately 70 per cent of its power needs through coal whereas we are using just five per cent of our coal for energy production.

Several MoUs were signed between the past government of the PPP and multinational exploration companies which even invested and began working on the infrastructural development of the area but after the removal of the PPP government Mian Nawaz Sharif scrapped those coal development projects on political grounds.

During the Musharraf regime a Chinese company was invited to invest in the project aimed at generating 600 MW of electricity but due to unfriendly attitude of Wapda and Nepra the Chinese company had to quit.

Now when we are facing the worst-ever energy crisis we must start developing Thar coalfields. The Sindh Coal and Energy Board has been established under the chairmanship of the Sindh Chief Minister which has still to show its performance. To end the energy crisis once for all development of Thar coal is the most feasible option available.

Power Generation In Bangladesh

In November 2010 Reuters reported that the Bangladesh Power Development Board (BPDB) had announced the aim of generate 9,000 megawatts of electricity by 2015. The country currently produces approximately 4,000 MW of electricity a day “against peak hourly demand of over 6,000 MW.

The BPDB called for tender bids on a number of new power plants including two coal-fired plants. One is a 300MW coal plant to be built near Chittagong port. The tender closes at the end of January 2011. The board has also sought tenders for a 650MW coal plant to be built near Mawa. Both projects are proposed to be constructed on a build own and operate basis for 25 years. Reuters reported that BPDB officials stated that in the near future thwy would call for bids for 10 new power plants to add another 4,000 megawatts of electricity to the national grid.

Local coal for power generation

THE Power Development Board (PDB) has reportedly proposed last week to form a public limited company to install coal-based power plants in future. According to PDB sources four mega coal-based power plants having capacity of producing 500 megawatt of electricity each would be established under the supervision of the proposed company by 2014. Several companies have already expressed interest to establish the plants under Public Private Partnership.

The country suffers from a serious shortage of electricity. According to sources the total generation comes to 3,200mw of electricity against the demand for 4,600mw. The crisis has reached a point of seriously hampering production in mills and factories. Several power plants are reportedly producing electricity less than their capacities. Some others have stopped production due to short supply of gas that fuels 80 percent of power generation. According to a projection, the country will need about 10,000mw and 14,000mw electricity by 2015 and 2020 respectively. But except for limited reserves of gas there is only coal to fuel power plants. So the proposal for installation of coal-based power plants is a step in the right direction.

It has been reported that PDB would use imported coal to run the proposed plants. Bangladesh has a proven reserve of 2,086 million tons of high quality coal. According to experts this coal is enough to generate 5,000mw of electricity for up to 90 years. It will also save about US$500 million that the country spends annually to import coal. Petrobangla had in June even proposed to export two lakh tons of coal from Barapukuria due to storage problem. Then what is the reason behind the idea of using imported coal instead of the local coal. The country should go for early extraction of its own coal resource.

New company to be set up to increase coal-based power generation

The government will form a new company styled ‘Bangladesh Coal Power Company’ to set up the planned coal-fired power plants and increase the country’s electricity generation by using the mineral officials. The power ministry has already decided to create the company after enlisting it with the Registrar of the Joint Stock Companies and Firms (RJSCF).

The proposed new company will boost electricity generation from coal which is abundant in northern Bangladesh. Immediately after formation of the company it will be engaged to facilitate setting up four coal-fired power plants to generate 2,000 megawatts (mw) of electricity each having generation capacity of 500 mw.

The power ministry has taken up the program for installing four coal-fired
power plants under the new concept of the private public partnership (PPP) where the government will own only a fraction of its shares for offering land and infrastructure. It will require around US$ 3.0 billion (Tk 210 billion) for setting up these coal plants. When contacted Chairman of Bangladesh Power Development Board (BPDB) ASM Alamgir Kabir said the board is now working on the formation of the new company to augment electricity generation from the coal-fired power plants.

The company will be constituted with the efficient people where some BPDB officials will also get appointment. The BPDB has already initiated the groundbreaking work and is now selecting sites for setting up the plants. It has primarily selected – Karnaphuli river bank in Chittagong near Mongla seaport in Khulna, Jazira on the bank of Padma and at Meghnaghat on the bank of Meghna – for setting up the plants for smooth transportation of coal.

Initially the planned power plants will be run with the imported coal from the global markets including the key exporting countries like Indonesia, Australia and India. The existing infrastructure like drafting in waterways and expansion of railway tracks will be required for efficient coal transportation, said a power ministry official. All the four proposed coal-fired power plants along with some independent power producer (IPP) projects will be put on offer during the road shows in three key important locations – New York, London and Singapore – in December next.

The major task of the proposed company will be to arrange finance necessary coal supply and develop required infrastructure. Despite having enormous coal reserves of around 3.0 billion tones in five different mines the country’s coal-fired power generation is limited to only one plant at Barapukuria having the generation capacity of 250 mw. Even the Barapukuria plant is struggling to generate electricity to half of its installed capacity.

The country is waiting for adoption of a national coal policy to start coal extraction from the mineral-rich northern region. The country’s overall electricity generation is now hovering around 3,800mw against the peak hour demand for over 5,500mw.

Bangladesh seeks bids for 300 MW coal-fired plant

Bangladesh has invited bids for a 300-megawatt coal-fired power plant to be set up on a build, own and operate basis (BOO) for 25 years. The tender for the plant to be built near the country’s main Chittagong port 300 km (188 miles) southeast of the capital will close on Jan. 31, next year. The bids have been invited as part of a government initiative to generate 9,000 MW of electricity by 2015.The BPDB is the regulator for power generation and distribution in the country where the gap between demand and generation has been growing.

Bids for a short-list of viable firms have also been invited for another 650 MW coal-fired plant to be set up at Mawa 50 km (31 miles) east of the capital, Dhaka also on a BOO basis and for 25 years. The bids for the short-list will close on Dec. 30.Energy-starved Bangladesh which faces a deficit of 2,000 MW of power aims to set up a number of power plants to cover the shortfall as quick as possible.

BPDB awarded a $114 deal to a Chinese firm — China National Machinery Import and Export Corporation to set up a 150 MW power plant in northern Sirajganj by May 2012. BPDB in the recent months signed deals with several foreign and local firms to set up plants or to buy electricity from their rental plants. Britain’s Aggreko PLC and seven other local firms were given deals to supply some 870 megawatts of power to the national grid for five years starting later this year.

Aggreko has already started generating 200 MW from two fuel oil-fired rented generator from August at $0.21 per kilowatt-hour. The British firm also won another deal last month to supply more 150 MW to the Bangladesh national grid from its two small gas-fired plant from February for three years at $0.07 per kilowatt-hour. Bangladesh will soon seek bids for 10 new power plants to add another 4,000 megawatts of electricity to the national grid.

US firms keen to invest in coal sector

American companies are keen to invest in Bangladesh’s coal sector. The US envoy apprised him that American energy companies are interested to help Bangladesh in developing energy sector. They particularly want to invest in coal mining after finalization of the coal policy by the government.

Moriarty noted that the United States would provide necessary assistance for the victims if Bangladesh side seek any help.A number of US companies including oil major Chevron have been operating in the country’s energy and power sector. But this is the first time it was learned that US energy companies are also interested in the coal mines.

Bangladesh has about five coal mines in the country’s northern region, having a total coal deposit of 2.5 billion tons.

Coal  In  Electrical Power System

World  coal  fired  power  plant  capacity  will  grow  from  1,759,000  MW  in  2010  to  2,384,000  MW  in  2020.Some  80,000  MW  will  be  replaced.So  there  will  be  705,000  MW  of  new  coal  fired  boilers  sales  will  average  70,000  MW.

Coal  fired  power  plants  generate  approximately  56%  of the U.S  electricity.A  healthy  economy  requires  the  effective  utilization  of  the  existing  infrastructure  as  new technologies  are  introduced.Coal  plays  a  vital  role  in  electricity  generation worldwide.Coal  fired  power  plant  currently  fuel  41%  of  global  electricity.In  some  countries  coal  fuels  a  higher  percentage  of  electricity.Germany  is  one  of  the  major  nation  who  converts  coal  in  electricity  generation.In  2008  the  gross  electric  power  generation  in  Germany  totalled  639  billion  KWH.A  major  proportion  of  the  electricity  supply  is  based  on  lignite (23.5%), nuclear  energy (23.3%)  and  hard  coal (20.1%).Natural  gas  has  a  share  of  13%  renewables (wind,water,biomass)  account  for  15.1%.

Table Coal  In  Electricity  Generation Outside Bangladesh

Name  Of  The  Country Total  Generation
                 South  Africa                                 93%
                 Australia                                77%
                 USA                                49%
                 India                                69%
                 Germany                                46%

Kogan  creek  power  station  of  Australia  has  a  capacity  of  7636 MW  and  it  produces  2.46%  of  electricity.Hassyan  power  station  of  Arab  Emirates  has  a  capacity  of  9000 MW  and  it  produces  1.35%  of  electricity.Altbach  power  station  of  Germany  has  a  capacity  of  1200 MW  and  it  produces  0.18%  of  electricity.Cottam  power  station  of  United  Kingdom  has  a  capacity  of  2000 MW  and  it  produces  3.5%  of  electricity.

Improvements  continue  to  be  made  in  conventional  power  station  design  and  new  combustion  technologies  are  being  developed.These  allow  more  electricity  to  be  produced  from  less  coal  known  as  improving  the  thermal  efficiency  of  the  electrical  power  station.Coal  will  continue  to  be  a  valued  resource  with  over  100 GW  of  new  coal  plants  projected  by  2020.Advanced  technology  is  required  to  meet  economic  and  environmental  goals.It  also  maintaining  diversity  manufacturing  capabilities  also  mention  environmental  goals as  its  security  concern.

Carbon Dioxide  Emission  Factors  For  Coal Across The World

Coal  is  an  important  source  of  energy  across  the  world  and  the  whole  world  depends on  this  fossil  fuel  for  electricity  generation  is  growing.The  combustion  of  coal  also  adds  a  significant  amount  of  carbon  dioxide  to  the  atmosphere  per  unit  of  heat  energy.In  modern  days  a  growing  concern  over  the  possible  consequences  of  global  warming which may  be  caused  in  part  by  increases  in  atmospheric  carbon  dioxide (a  major  greenhouse  gas)  and  also  because  of  the  need  for  accurate  estimates  of  carbon  dioxide  emissions .The  Energy  Information  Administration (EIA)  has  a  developed  factors  for  estimating  the  amount  of  carbon  dioxide  emitted  as  a  result  of  coal  consumption. EIA’s  emission  factors  will  improve  the  accuracy  of  estimates  of  carbon  dioxide  emissions  because  they  reflect  the  difference  in  the  ratio  of  carbon  to  heat  content  by  rank  of  coal  and  state  of  origin.

Two types of carbon dioxide emission factors have been developed. First are basic emission factors covering the various coal ranks by State of origin. These basic emission factors are considered as “fixed” for the foreseeable future until better data become available. Second are emission factors for use in estimating carbon dioxide emissions from coal consumption by State with consuming-sector detail. These emission factors are based on the mix of coal consumed and the basic emission factors by coal rank and State of origin. These emission factors are subject to change over time, reflecting changes in the mix of coal consumed.

EIA’s emission factors will not only enable coal-generated carbon dioxide emissions to be estimated more accurately than before but they will also provide consistency in estimates. Energy and environmental analysts will find EIA’s emission factors useful for analyzing and monitoring carbon dioxide emissions from coal combustion, whether they are estimated by the State of origin of the coal, consuming State, or consuming sector.

West of the Mississippi River the emission factors for bituminous coal range from more than 201 pounds of carbon dioxide per million Btu in Missouri, Iowa, and Nevada to more than 209 in Arizona, Arkansas, and Montana. About 16 percent of the 1992 coal output west of the Mississippi was bituminous coal with production chiefly from Utah, Arizona, Colorado and New Mexico.

Sub bituminous coal is the predominant rank of coal produced west of the Mississippi River accounting for 62 percent of the region’s total coal output in 1992. Sub bituminous coal in Wyoming’s Powder River Basin the principal source of this rank of coal, has an emission factor of 212.7 pounds of carbon dioxide per million Btu. This is the same as for sub bituminous coal in Colorado, but slightly below that in Montana. The lowest emission factor for sub bituminous coal is in Utah (207.1) and the highest is in Alaska (214.0).

 Coal Costs

On the heels of President Obama’s speech supporting clean coal it doesn’t seem that this energy source is leaving anytime soon. But while advocates often tout the inexpensiveness of coal a new study reveals that the substance may be costing the U.S. up to $500 billion per year.

Harvard professor and Huffington Post contributor Paul Epstein( M.D., M.P.H.) has just announced the release of a new study in the Annals of the New York Academy of Sciences entitled “Full Cost Accounting For the Life Cycle Of Coal.”

According to Tree Hugger Epstein’s study is considered one of the first to examine the costs of coal in its entirety – from extraction to combustion. So how did Epstein reach the astronomical number of $500 billion/yr.

First, public health costs. In Appalachian communities alone health care, deaths, and injuries from coal mining and transporting cost $74 billion per year. Beyond Appalachia, the health costs of cancer, lung disease, and respiratory illnesses related to pollutant emissions totals $187.5 billion per year. According to Climate Progress, processing coal releases heavy metal toxins and carcinogens which in turn may lead to long-term health problems. The American Lung Association reports on a study finding that coal-powered electricity caused over 13,000 premature deaths in 2010.

Beyond health problems add the cost of coal’s effect on land use energy consumption and food prices plus the cost of toxic waste spills and cleanup… $500 billion. The public is unfairly paying for the impacts of coal use. Accounting for these ‘hidden costs’ doubles to triples the price of electricity from coal per kWh, making wind, solar, and other renewable very economically competitive.

According to Epstein, we must focus more on green city planning. Most importantly, “We need to phase out coal rapidly.”

Tapping Coal For Clean And Low-cost electricity In Bangladesh

Australian firm proposes to generate 400MW power from Bangladesh’s unmineable coal by 2015. An Australian company with expertise in underground coal gasification (UCG) technology has proposed to produce 400 megawatts of clean coal power from Bangladesh’s unmineable coal within five years at a very low cost.

Making a presentation to Petrobangla  Mitchell Group of Australia said it could undertake a pilot project at its own cost in the deeper part of Barapukuria coal mine or in Jamalganj.

The first phase delivery of 10 to 40 MW power from the pilot project is possible within two years — 2011-12. By 2015, the company will be able to deliver 400 MW power.

Sources present at the presentation said it is very lucrative as power generated from such a plant will be as cheap as that produced by using gas. A part of Barapukuria is presently unmineable by using open pit or underground mining methods as coal rests at a depth of 500 metres.

On the other hand the coal deposit in Jamalganj is by far the biggest one discovered in the country. Jamalganj has more than one billion tones of coal. Unfortunately the deposit rests between 600 and 1,100 metres below the surface making it inaccessible using conventional mining methods.

The Costs of Generating Electricity

• Coal plant

• Pulverized fuel (PF) steam plant.

• Circulating fluidized-bed combustion (CFBC) plant.

• Integrated gasification combined-cycle (IGCC) plant.

• Gas plant.

• Open-cycle gas turbine (OCGT) plant.

• Combined-cycle gas turbine (CCGT) plant.

• Nuclear fission plant.

• Biomass (poultry litter)

• Bubbling fluidized-bed combustion (BFBC) plant;

• Wind turbines

The cost of generating electricity, as defined within the scope of this study, is expressed in terms of a unit cost (pence per kWh) delivered at the boundary of the power station site. This cost value, therefore, includes the capital cost1 of the generating plant and equipment; the cost of fuel burned (if applicable); and the cost of operating and maintaining the plant in keeping with UK best practices. Within the study, however, the ‘cost of generating electricity’ is deemed to refer to that of providing a dependable (or ‘firm’) supply. For intermittent2 sources of generation, such as wind, an additional amount has been included for the provision of adequate standby generation.

Comparing Per Kilowatt-Hour Cost Estimates for Multiple Types of Energy Production

Hydroelectric is the most cost effective at $0.03 per kWh. Hydroelectric production is naturally limited by the number of feasible geographic locations and the huge environmental infringement caused by the construction of a dam. Nuclear and coal are tied at $0.04 per kWh. This comes as a bit of a surprise because coal is typically regarded as the cheapest form of energy production. Another surprise is that wind power ($0.08 per kWh) came in slightly cheaper than natural gas ($0.10 per kWh). Solar power was by far the most expensive at $0.22 per kWh—and that only represents construction costs because I could not find reliable data on production costs. Also, there is a higher degree of uncertainty in cost with wind and solar energy due to poor and varying

data regarding the useful life of the facilities and their capacity factors. For this analysis the average of the data points are used in the calculations.

Table  Extrapolation of Results

Energy Source % of Total Cost per kWh Weighted Avg Cost
Nuclear 19.7% $0.04 $0.008
Hydro 6.1% $0.03 $0.002
Coal 48.7% $0.04 $0.022
Natural Gas 21.4% $0.10 $0.022
Petroleum 1.1% $0.10 $0.001
Other Renewables 3.0% $0.15 $0.005
100% $0.059

Least-Cost Analysis of Bangladesh

About 85% of electricity in Bangladesh is produced from gas-based power plants. Coal,

Hydropower, heavy fuel oil (HFO) and diesel are the other sources of energy for power generation. Inadequate investment in upstream gas field development in recent years has resulted in a shortage of gas for the industrial sector and for electricity generation. This has constrained power generation with electricity utilities resorting to load shedding while industrial consumers have been using captive generation facilities that require diesel. As an immediate measure to reduce gas shortage the government has decided not to provide assured gas supply to a number of new power projects and has asked promoters to develop these projects on a dual fuel model (to be run on diesel or HFO).

Table indicates the cost of power generation using various fuels in Bangladesh:

Fuel Source Economic Generation Cost Per Unit Tk/kWh
Gas 4.2
Coal (local) 3.7
Coal (Imported) 5.4
HFO 12.1
Diesel 25.2
Hydropower 1.4

Bangladesh has sizable coal reserves in the north-west region, currently only one coal-based power plant is operating and it has been facing fuel shortages given constraints in coal production. The development of domestic coalfields will take time and will require significant investment. Imported coal-based power generally costs about Tk 5.4/kwh ($0.077) at current coal prices. In the current situation, power imports fromIndia3 are expected to be the most feasible least-cost way of overcoming existing power shortages in Bangladesh.

Cost of Barapukuria Coal Mine Project

Total Cost :                                          US$ 197million

US$:                                                    172 million in F.C.

US$:                                                     25 million in L.C.

Expected annual production:               1.2 million tons

Market price:                                       US$ 90 million

Annual production cost:                      US$ 40.8 million

Foreign currency worth:                      US$ 45 million will be saved per annum

64 years will be required to extract     300 million tons of coal at the above rate

The discovery of such huge deposits of coal and hard rock is a blessing for Bangladesh and proper development of these resources will open a new era for the country to enter the industrial world. In the modern world the sustainable economic conditions of any nation depend on how developed that country’s industrial is especially in the field of mineral resources. So minerals based industries are an important factor for accelerating the economic growth of a country. Now Bangladesh has an opportunity to build up mineral-based industries as she has sufficient mineral resources on which industries can develop. Full-capacity exploitation of these resources will create thousands of new jobs at the mine sites and later on at industrial sites which will help to alleviate the country’s poverty by providing jobs. All these together will accelerate the country’s economic development. It may be concluded that proper development and utilization of these resources will help us to save a considerable amount of foreign currency and will contribute a great deal to the national economy and reshape our socio-economic infrastructure.

Merits of coal fired power plant

1.         Coal is a stable energy source

2.         Coal is a key source of power generation

3.         High efficiency

4.         Low cost

5.         Low maintenance

Looking at other countries, coal makes up 50% of power generation in the USA, the largest consumer of energy, and 80% in China, where rapid growth in energy consumption is forecast. As coal accounts for 41% of the world’s power generation, it will continue to play a major role for the foreseeable future.

Emissions to air

The principal emissions from burning coal are carbon dioxide (CO2), sulphur dioxide (SO2), oxides of nitrogen (NOX), hydrogen chloride (HCl), and particulates (dust). Our generating units have all been retrofitted with Flue Gas Desulphurization (FGD) equipment which removes at least 90% of SO2 and HCl emissions before the flue gas is released via the chimney into the atmosphere.

We maintain investment in our emissions abatement equipment and consider this to be a high priority. Our FGD plant already complies with known future SO2 emissions limits to 2016. In 2008 we completed a programme to retrofit all units with low NOX technology – Boosted Over Fire Air systems – in order to ensure compliance with the NOX requirements of the Large Combustion Plant Directive (LCPD) which were strengthened in 2008.

Discharges to water

Procedures are in place to ensure that all discharges and drainage to water are monitored and treated where necessary to meet our discharge consent limits. There are a number of sources of discharge and drainage as part of the electricity generation process, including the cooling water used to cool the condensers, which as part of the steam cycle condense steam to water after it leaves the turbines and before returning to the boilers. Cooling water is abstracted mainly from the River Ouse and boiler feed water originates from two boreholes on site. Approximately half of the water is returned to the River Ouse at a few degrees warmer than the river water.

The FGD process produces effluent water which is treated in a specially designed plant before it is discharged to the river, and there is also drainage from the main plant, coal plant and roads.

 Disposals to land

When coal is burnt, ash is left as a residue. The finer particles of ash, pulverised fuel ash (PFA,) are collected from the flue gas by electrostatic precipitators; the heavier ash, furnace bottom ash (FBA) falls to the bottom of the boiler. The majority of ash is sold to the construction industry with the remainder sent for landfill at the power station’s adjacent Barlow Mound ash disposal site, which over time has been developed into farmland, woodland and wetland features providing a haven to many species of wildlife and birdlife.

We pay landfill tax on the PFA disposed of to the Barlow Mound. Through the Landfill Tax Credit Scheme, we are able to claim a tax credit against our donations to recognised Environmental Bodies. We have worked with Groundwork Selby since 2001 on projects designed to help mitigate the effects of landfill upon our local community.

 Environmental impacts of coal power

Burning coal is a leading cause of smog, acid rain, global warming, and air toxics. In an average year, a typical coal plant generates:

  1. 3,700,000 tons of carbon dioxide (CO2), the primary human cause of global warming–as much carbon dioxide as cutting down 161 million trees.
  2. 10,000 tons of sulfur dioxide (SO2), which causes acid rain that damages forests, lakes, and buildings, and forms small airborne particles that can penetrate deep into lungs.
  3. 500 tons of small airborne particles, which can cause chronic bronchitis, aggravated asthma, and premature death, as well as haze obstructing visibility.
  4. 10,200 tons of nitrogen oxide (NOx), as much as would be emitted by half a million late-model cars. NOx leads to formation of ozone (smog) which inflames the lungs, burning through lung tissue making people more susceptible to respiratory illness.

5.   720 tons of carbon monoxide (CO), which causes headaches and place additional stress on people with heart disease.

6.   220 tons of hydrocarbons, volatile organic compounds (VOC), which form ozone.

7.   170 pounds of mercury, where just 1/70th of a teaspoon deposited on a 25-acre lake can make the fish unsafe to eat.

8.   225 pounds of arsenic, which will cause cancer in one out of 100 people who drink water

Background

Geological Survey of Bangladesh (GSB) discovered presence of extensive coal reserve at relatively shallow depth in April 1985 in Barapukuria under Parbatipur-Upazilla of Dinajpur. GSB undertook further investigation in 1986 and 1987, involving more detailed gravimetric, magnetic and geophysical surveys to confirm the presence of approximately 303 million tones of high quality coal in six horizons over an area of 6.68 square kilometers. Subsequently, Bangladesh oil, Gas and Mineral Corporation (Petrobangla) with the assistance of Overseas Development Administration (ODA), UK concluded a detailed Techno- economic feasibility study by engaging M/S War dell Armstrong, UK in May 1991. The Major findings were as under

Reserve of Coal                          : 390 Million tones
Depth of coal                              : 118-509 meter.
Nos. of coal layer                        : 6
Average thickness of coal Seam : 36 m (6th Seam)
Composition of coal                    : Ash12.4%, Sulphur 0.53%, Noisture 10%
Rank of coal                                : Bituminous (high volatile).
Calorific value of coal                  : 25.68 MJ/KG (11040 BTU/Ib.)
Yearly Production                        : 1 million tones.
Coal extraction method                : Multi- Slice Long wall.

During development of Barapukuria Coal Mine as well as load testing/trial run, coal as obtained from the mine, on Chemical Analysis, confirmed composition of coal, Rank of coal and Calorific value of coal as predicted.

Objective

The Mine would produce 1 million tones of coal per annum when commercial production will commence out of which 65% will be used in 250 MW coal fired power station and remaining 35% will be used in brick fields and other domestic purposes.

Project implementation

M/s China National Machinery Import and Export Corporation (CMC) as lead partner of Consortium proposed supplier’s credit for the implementation of Barapukuria Coal Mine Project. The Project Concept Paper (PCP) was approved by ECNEC on 11th March 1992 and Project Proforma was approve by DPEC on 21st April 1993 at a total estimated cost of Tk.8873.55 Million including foreign exchange component of Tk.4868.76 million .The contract between M/S China National Machinery Import and Export Corporation (CMC) as lead partner of Consortium and Petrobangla was signed at the total lump-sum amount of US $ 194.91 million including supplier’s credit amounting to US$ 109.235 million on 7th February 1994. CMC commenced physical works on 1st June 1996 for the implementation of Barapukuria Coal Mine Project. As per contract the scheduled completion date was June 2001. On completion of installation works of two shafts, when development works of Pit Bottom were in progress underground mine inundated due to on rush of water. Consequently underground development works on mine was suspended for about 30(thirty) months.

This was necessitated to carry out additional geological & hydro-geological investigation in order to acquire additional date based on which CMC had to modify earlier approved mine design/layout. The underground mine development works restarted from October 2000. The PP was revised on the basis of modified mine design/layout and approved by ECNEC on 15th August 2004 at the estimated cost of Tk. 14311.27 million (Equivalent to US $ 251.08 Million). The project was scheduled for completion by December 2004 as per revised PP. The original Contract was amended by contract amendment keeping the original contract value unchanged with re- appropriation of item – wise costs. As per the revised schedule the completion period was fixed at 20th October 2004.

Management and production  contract

After completion of construction of Barapukuria coal mine on 31st may 2005, a Production Management and Maintenance (M&P) contract was signed with China National Machinery Import and Export Corporation (CMC) led consortium with Xuzhou Coal Mining Group Company Limited (XMC) on 4th June, 2005 for a period of 71 months to produce 4.75 million metric ton of coal from the 1st slice of underground mine at a total cost of USD 82.30 million. As per the terms of contract, CMC already paid Performance Security Guarantee (10% of total contract price) and Down Payment Guarantee (10% of total contract) for effecting the Contract, BCMCL paid Down Payment of local currency portion (10%) on 08-09-2005 and foreign currency portion (10%) on 15-11-2005. Since the M&P contract is fully effective, CMC-XMC produced coal from the Long Wall Face No. 1106 and 1101.

Present status                                                                                                                                                                   

Two Long wall Faces were constructed and two sets of Face Equipment were provided under the Construction Contract. One Long wall Face (1110) with incomplete production along with a set of Face Equipment had to be sealed off due to gas emission. To reopen 1110 Long wall Face, preparation work for Nitrogen Injection has been taken by CMC.

With only one set of Long wall Face Equipment available, the mine started its production from 1109 Long wall Face since March 2007. Production from this face started on 7 March 2007 after a gap of 6 months due to the following reasons:

I. 1109 Long wall Face development work delayed due to the fact of encountering unexpected geological and environmental problems. 176 meters excavated roadway had to be abandoned due to large roof fall and hot strata water ingress. 1109 Face required a redesign.

II. Installation and commissioning of Long wall equipment were delayed due to non availability of materials and spares needed importing from China.

Production from this Face is adversely affected by the following reasons:

a) Due to geological condition of the coal seam, Long wall Face open off cut developed inclined at an angle of 220-230. Equipment like heavy Hydraulic Powered Roof Support (HPRS) set on this inclined floor has great tendency to slip and tilt downward.

b) Adverse strata condition. Coal is friable and prone to caving.

c) Adverse environmental conditions. High temperature (390 Celsius) and humidity (100%) made the working condition difficult.

d) Relatively high strata water inflow washing down the floor of Long wall Face and causing instability to the HPRS.

e) Miners are getting fainted, heat stroke, and sick due to adverse environment.

Having adverse condition and lot of constrains, CMC successfully started the recovery work of 1110 Longwall Face from 18 August 2007.

Hardgrove Grindability Index (HGI)

Coal grind ability indicates the ease for grinding coal to power.The bigger of grind ability index, the easier to be grinded. Hard grove Grind ability Indices indicate that the coal is moderately hard, but not unusually so for Gondwana coal .

Chemical Properties (Proximate Analysis)

The Proximate analyses of coal samples have been done by War dell 1991. Average results of chemical analysis of Barapukuria Coal, Dianjpur, Bangladesh is given below.

Table Proximate Analysis of Design Coal Sample

SeamVI

Zone

Approzimate Thickness (m) Estimated Coal Quality (At 10% Moisture)
Rang Mean Ash(%) VolatileMetter

(%)

FixedCarbon

(%)

TotalSulphur

(%)

MJ/Kg Btu/Ib
B 3.7-6.5 5.4 9.0 29.9 51.1 0.61 26.81 11525
C 3.2-5.3 4.3 16.2 28.2 45.6 0.58 24.27 10435
D 3.1-4.3 3.9 10.8 30.2 49.0 0.57 26.33 11320
E 3.5-7.2 4.9 13.3 29.3 47.4 0.54 25.39 10915
G 4.2-7.5 5.5 16.9 26.5 46.6 0.56 23.74 10205

Ultimate Analysis

Elementary Analysis of coal samples of seam VI of GDH 38 has been done by GSB. The results of analysis are given in the Table 3, 4 & 5.

Table Elementary Analysis of coal samples

Seam No %C %11 %N % Ash Remarks
VI 77.35 4.95 2.30 3.55 In Whole Sample
VI 78.70 5.30 2.45 2.15
VI 72.75 4.75 2.20 8.95
VI 77.85 5.00 2.45 1.75 Vitrinite Concentration
VI 78.60 5.05 2.50 0.72
VI 78.95 5.10 2.50 1.15
VI 80.20 4.70 2.35 0.08
Geological Survey of Bangladesh 1996

Coal Sale

Up to June 2006, a total of 4, 81,196.53 metric ton of coal has been produced, which includes the production of 3, 03,015.93 metric ton in the fiscal year of 2005-06. The production resulting from the coal produced during roadway development, during the Acceptance Tests of two Long wall and four Road header systems and commercial production from Long wall face. Up to June 2006, 1,89,919.58 metric ton of coal has been sold to the coal-fired industries. This includes the sale of 45,020.44 metric ton of coal during the fiscal year of 2005-06. Total revenue earned from the sale of coal for domestic uses up to June 2006 was Taka 75.85 crore. Up to June 2006, a total of 2, 09,234.57 metric ton of coal has been delivered to Power Development Board at the rate of US Dollar 60.00 Per MT as fixed by the Government.

Applying for purchasing coal

For purchasing coal, an application will have to be made addressed to the Managing Director of Barapukuria Coal Mining Company Limited. Application can be made on a plain paper or on a form available at Markrting Section, Head Office, Barapukuria Coal Mining Company Limited, Chowhati, Parbatipur, Dinajpur. For any assistance regarding this, personnel of the Marketing Section can be contacted.

Payment Method

Payment is accepted in the form of bank draft payable to BARAPUKURIA COAL MINE PROJECT and no cash money is accepted. Bank draft made at Sonali Bank, Barapukuria Coal Mine Project Branch, Parbatipur, Dinajpur or Janata Bank, Phulbari Branch, Dinajpur is preferred to that made at other different banks for quick issuance of delivery order for sale of coal. Delivery order for sale of coal against bank draft made at other than above-mentioned two branches is issued after the confirmation of transfer of money to the the company account, which sometimes may delay up to 48 hours the issuance of delivery order. Payment in the form of bank draft will have to be submitted to the Accounts Section of the Company. For any query regarding this, personnel of the Marketing Section can be contacted.

Measuring Method

At the delivery point, that is, at the mine site, coal is measured by using Computer Controlled and BSTI certified UK made Avery weighing scale.

Coal Loading

Coal can be loaded on the trucks/vehicle by using mechanized pay loading facility provided at the delivery point by Barapukuria Coal Mining Company Limited. Using of the company’s loading facility will cost Taka15.00 (fifteen only) per ton. Coal can also be loaded on the trucks/vehicle by using different facilities provided by other than Barapukuria Coal Mining Company Limited, which may cost approximately Taka 27.00(twenty seven only) per ton.

Transport Facility

For transporting coal, trucks may be available on hire at Phulbari, about 7 km away from the delivery point. Rate of transportation will vary depending up on the destination, route and season of use of coal. As a rough estimate, transportation cost from the delivery point to Dhaka for per tonne of coal may be around Taka500.00.

CONCLUSION

 Power Crisis has been a long clamor in Bangladesh and this seems to persist for the coming decade or so. Beyond optimistic illusions, facts and realities are too fierce to be accepted. Energy infrastructure of Bangladesh is quite small and insufficient but the demand is very high. The per capita energy consumption in Bangladesh is one of the lowest (136 kWH) in the world. Electricity is the major source of power for country’s most of the economic activities. In our country, only 40% of the population has access to electricity because of the shortage of our power generation and this lacking can be filled by using some coal based power plant. From the research we have seen that the environment and transportation system of Bangladesh is positive to establish a coal based power plant. In our country we have few coal pits and the quality of our coal is quite rich and it can be used easily to produce Electricity. In a coal based power plant the Major equipments are 3 units of steam generator, 3 units of steam turbine generator and other associated systems in line with specific tender document taken as reference and as per the scope of work. Besides, fuel details, water arrangements, layout, pollution standards, logistics planning, power evacuation arrangements, water requirements, plant layout, pollution, logistics arrangements and land are required. Now if we focus on our transportation system we will find that most of our transportation route is on plain land. So if any electric power company doesn’t have their own coal manufacture plant then it can easily be transported by road, rail or water transport. Though this transportation costs are a little expensive. Proposals have been made to build a few coal based power plants in our country. Because of some difficulties yet it is not implemented. Growing economies always need a proportional need for power. Considering the recent condition of our country it may be seen that the lack of electricity has been increased day by day. Country like Bangladesh has a required growth in power sector close to 15 %. In order to match the accelerated need of country, there is urgent need to take the challenge to squeeze the time and cost required to complete a coal based power project. It would be a great relief to fund hungry  power projects.

energy

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EEEScience

Report on Electronic Media

 Introduction:

Television is a medium which attract a wide audience. It is an ideal tool for information, communication, education, entertainment and news etc. Television is like a window to see outer world. Through this window we can see what is happening around us. In Bangladesh there are many television channels. These televisions channels are working as strong electronic media in our country. These channels have created so much competitive field among them that continuously surfing those channels has become a habit for us. Thus a research was conducted through questionnaire survey to extract the information based on the perception of the audience about the electronic media in our country.

This report entitled ‘Urban Based Electronic Media Preferences Analysis’ is a fundamental requirement for the completion of the course Marketing Research (MKT-409). The main purpose of this report is to extract the information of the electronic media in the context of Bangladesh using specific research method. Under the instruction and guidance of the course instructor Mr. Shamsad Ahmed, we have taken the initiative to conduct the research and prepare this report with much precision and by being completely unbiased.

Electronic Media

The general objective of this report is to provide a synopsis of the electronic media of Bangladesh. It is also required for the completion of this course. Beside the general objective, the objectives behind this report are given below:

Primary objective:

The primary objective of the report is—

      To analyze on the issue ‘Urban Based Electronic Media Preferences Analysis’.

      To disclose the precise scenario of the electronic media through survey and SPSS software.

      To analyze and recommend on the mentioned issues.

Secondary objective:

The secondary objective to prepare this report is—

      To fulfill the requirements of our course Marketing Research.

      To have a clear understanding about the activity of specific research technique that is survey.

      To illustrate the position of Electronic Media based companies.

      To analyze the audiences demographic profile.

      To identify the audiences preference.

      To have a clear understanding about the SPSS software.

      To fulfill the requirements of our course “Marketing Research”.

      To gather experience and knowledge of doing a professional report.

This research study will cover the topic “Urban Based Electronic Media Preferences Analysis’” and its related issues. It also includes recommendations against the selected issues. This report can be used as a secondary source for the Electronic Media based companies.

To fulfill the objective of this report collection of relevant, accurate, standardized and needful information was required. To make this report reliable we have collected data from both primary sources and secondary sources. Special consideration was given so that chances of biasness could not arise. Special consideration was given so that chances of biasness could not arise. The sources used were:

Primary sources:

Primary data is defined as data which originates as a result of that particular investigation. We have collected primary data through questionnaire survey with various people. The primary data related to Electronic Media of Bangladesh was collected from the audiences by the method of survey that we conducted. Structured close ended questions were constructed to extract the primary data.

Secondary sources:

Secondary data represents the data which are made by others but it is useful for another purpose or research. As a part of collecting data from secondary sources, we have referred different books of Marketing Research. We collected our data from the magazine, news paper, libraries and also from the websites.

No study is beyond any limitations. While doing this research study we had to face some difficulties. The limitations of the research activities are as follows—

      We did not have so much experience for conducting research and preparing the report very frequently, though we are in learning position.

      In questionnaire survey some participants were unenthusiastic to provide enough information.

      The respondents hid their personal information.

      There was lack of precise information; both primary and secondary.

      There was not enough time to analyze the selected issues.

      Our resources (such as, human resource, financial resource, etc) were limited. So it was hard for us to prepare a professional report with our limited resources.

      First time ever we are using the SPSS software.

Research Design:

The design of the research that we carried to explore the opinion of the audiences of electronic media was conclusive to large extent. The research was formal and structured. It is based on large, representative sample, and the data obtained from the research will be used for Managerial decision making.

Sampling Design:

The size of the sample for the research was 500 respondents. The procedure adopted for sampling was Non Probabilistic Quota Sampling. The quota was formed based on occupations. The numbers of respondents was restricted by ten categories of occupations.

 Instruments:

The basic instruments used for the research were:

 SPSS software

      Structured Close Ended Questionnaire

      Computer

      MS Words

      Printer

Data Analysis Method:

For analyzing the data, we used SPSS software. The questionnaire consisted of ten close ended questions. The questions were basically formed with the purpose of providing descriptive information regarding the electronic media of Bangladesh. The data analyzed provided the information regarding the channel preference, program preference, factor preference, ranking of the channels, favorable program, unfavorable program and demographic profile of the respondents.

The factors for influencing the audiences were analyzed by factor reductions. This was done to separate the factors in two groups based on similarities in meaning.

The demographic profile of the respondents was used to formulate three clusters. The clusters were differentiated by the characteristics like gender, age, occupation, family members and family income.

Gender Distribution

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

342

68.4

68.4

68.4

2

158

31.6

31.6

100.0

Total

500

100.0

100.0

We have surveyed total 500 respondents (audiences). 342 of them were male and rests of 158 were female. That is out of the total respondents who were surveyed, 68 per cent of them turned out to be male whereas the rest 32 per cent were female. This vast difference is due to the number of respondents that were kept under each occupation.

Initial Cluster Centers

Cluster

1

2

3

Gender

1

2

1

Age

6

4

3

Education

7

4

1

Occupation

7

1

5

Family member

4

3

1

Monthly family income

500000

3000000

1500

Iteration History (a):

Iteration

Change in Cluster Centers

1

2

3

1

.000

.000

28042.266

2

.000

.000

.000

a. Convergence achieved due to no or small change in cluster centers. The maximum absolute coordinate change for any center is .000. The current iteration is 2. The minimum distance between initial centers is 498500.000.

Final Cluster Centers:

Cluster

1

2

3

Gender

1

2

1

Age

6

4

5

Education

7

4

6

Occupation

7

1

5

Family member

4

3

3

Monthly family income

500000

3000000

29542

Number of Cases in each Cluster:

Cluster

1

1.000

2

1.000

3

459.000

Valid

461.000

Missing

39.000

 

 

Bangla Channel Viewer:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid Viewer

478

95.6

95.6

95.6

Non viewer

22

4.4

4.4

100.0

Total

500

100.0

100.0

From the surveyed prople about 95.6% of the audiences watch Bangladesh TV channels and rests of the 4.4 % do not watch Bangladeshi TV Channels.

Statistics:

r1

r2

r3

r4

r5

r6

r7

r8

r9

r10

N Valid

429

438

452

458

451

383

412

400

367

414

Missing

71

62

48

42

49

117

88

100

133

86

Mean

5.12

7.12

3.32

2.62

2.78

6.80

5.81

5.62

7.61

5.73

Mode

5

10

1

2

1

8

5

7

10

7

BanglaVision is a new satellite TV channel that pledges to play a positive role in building the nation through healthy entertainment. It’s program lineup includes dramas, talk shows, feature films, entertainment programs etc and eight news bulletins in Bangla and one in English.

For the first time ever you can watch uninterrupted coverage of Asia’s leading international TV channels, over the Internet.

Jump TV proudly presents bangla language channels from Bangladesh. Enjoy an enticing palate of top quality programs ranging from news, entertainment, popular drama serials, musical programs, movies, documentaries, children’s programs to cultural programs and much more!

Amaar Ami

Bangla vision:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

25

5.0

5.8

5.8

2

43

8.6

10.0

15.9

3

56

11.2

13.1

28.9

4

62

12.4

14.5

43.4

5

65

13.0

15.2

58.5

6

54

10.8

12.6

71.1

7

33

6.6

7.7

78.8

8

44

8.8

10.3

89.0

9

34

6.8

7.9

97.0

10

13

2.6

3.0

100.0

Total

429

85.8

100.0

Missing System

71

14.2

Total

500

100.0

One of the main types of broadcast media in Bangladesh is TV, namely: “Bangladesh Television”. Bangladesh Television is the only terrestrial channel in the country. Several satellite TV stations have also made headway in Bangladesh.

Bangladesh Television is a government owned TV station. Very few broadcasts contain information about the political opposition until the general elections become nearer and the government in power takes control.

BTV:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

31

6.2

7.1

7.1

2

24

4.8

5.5

12.6

3

14

2.8

3.2

15.8

4

36

7.2

8.2

24.0

5

31

6.2

7.1

31.1

6

26

5.2

5.9

37.0

7

29

5.8

6.6

43.6

8

33

6.6

7.5

51.1

9

64

12.8

14.6

65.8

10

150

30.0

34.2

100.0

Total

438

87.6

100.0

Missing System

62

12.4

Total

500

100.0

ATN Bangla is the first Bengali digital cabletelevision channel. It transmits from its studio in Dhaka, Bangladesh. The channel is transmitted in South Asia, the Middle-east, Europe, and North America. The channel offers a wide variety of programming including news, movies, dramas, talk shows, and more.

ATN:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

98

19.6

21.7

21.7

2

93

18.6

20.6

42.3

3

88

17.6

19.5

61.7

4

62

12.4

13.7

75.4

5

42

8.4

9.3

84.7

6

30

6.0

6.6

91.4

7

17

3.4

3.8

95.1

8

8

1.6

1.8

96.9

9

9

1.8

2.0

98.9

10

5

1.0

1.1

100.0

Total

452

90.4

100.0

Missing System

48

9.6

Total

500

100.0

Channel-i, a Bangla-language channel, offers entertainment for the whole family and was the first digital Bangla channel in Bangladesh. Channel-i, one of the most highly rated Bangla channels, has become very popular among views for its wide range of programming including dramas, mega serials, musical programs, live interactive talk shows, magazine programs, agricultural programs and informative news bulletins broadcast 4 times a day.

Channel i

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

126

25.2

27.5

27.5

2

140

28.0

30.6

58.1

3

98

19.6

21.4

79.5

4

48

9.6

10.5

90.0

5

16

3.2

3.5

93.4

6

10

2.0

2.2

95.6

7

6

1.2

1.3

96.9

8

4

.8

.9

97.8

9

7

1.4

1.5

99.3

10

3

.6

.7

100.0

Total

458

91.6

100.0

Missing System

42

8.4

Total

500

100.0

NTV is a Bengali language satellite television channel based in Bangladesh. It started operation in 2003. It was founded by Mosaddeq Ali Falu, a politician and former Member of Parliament from the ruling Bangladesh Nationalist Party. It is one of the most popular Bengali TV channels in the country. In the anniversary of the channel, the founder expressed interest in creating NTV2 to satisfy the watchers further, but however it is a matter of fun now that he is in jail and, all of his properties have been seized by the government. The channel broadcasts excellent coverage of news, soap shows, educational, religious and politics related programs.

NTV:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

143

28.6

31.7

31.7

2

105

21.0

23.3

55.0

3

82

16.4

18.2

73.2

4

60

12.0

13.3

86.5

5

22

4.4

4.9

91.4

6

16

3.2

3.5

94.9

7

3

.6

.7

95.6

8

9

1.8

2.0

97.6

9

4

.8

.9

98.4

10

6

1.2

1.3

99.8

21

1

.2

.2

100.0

Total

451

90.2

100.0

Missing System

49

9.8

Total

500

100.0

Boishakhi Media Lid. is a private sector effort, dedicated to the creative presentation of television technology for Bangla speaking people all over the world. The company has established round-the clock satellite television channel aimed at the a worldwide audience with programming depicting Bangla culture, history, geography, people, language, and faiths responding to both national and international needs and demands. The name of the channel is “BOISHAKHI”.

Boishakhi has a very experienced team of programmed makers, technical and management consultants with intimate knowledge and experienced of running a television station. Boishakhi has its own digital facilities with a large scale studio, a dedicated news studio, news room with its own independent news

gathering facilities, computerized editing facility and in house transmission/broadcast facility based in

Dhaka, Bangladesh.

Boishakhi will maintain a high-level of quality, technical efficiency and reliability while keeping up to date with state of the art technology. Given the need for a widely accessible platform Boishakhi intends to broadcast Globally, reaching out to a language group that is the world’s”4th most widely spoken” as declared by the United Nations.

It can be safely said that “Boishakhi” as a global and Bangla speaking channel will be available to 210 Million Bangalis worldwide.

Boishakhi:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

5

1.0

1.3

1.3

2

7

1.4

1.8

3.1

3

15

3.0

3.9

7.0

4

25

5.0

6.5

13.6

5

48

9.6

12.5

26.1

6

62

12.4

16.2

42.3

7

64

12.8

16.7

59.0

8

66

13.2

17.2

76.2

9

57

11.4

14.9

91.1

10

34

6.8

8.9

100.0

Total

383

76.6

100.0

Missing System

117

23.4

Total

500

100.0

RTV is a satellite television channel broadcast from Bangladesh. It started operation on 26 December2005.[1] It mainly broadcasts programmed in Bengali language.

RTV:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

14

2.8

3.4

3.4

2

16

3.2

3.9

7.3

3

27

5.4

6.6

13.8

4

40

8.0

9.7

23.5

5

85

17.0

20.6

44.2

6

77

15.4

18.7

62.9

7

64

12.8

15.5

78.4

8

45

9.0

10.9

89.3

9

29

5.8

7.0

96.4

10

15

3.0

3.6

100.0

Total

412

82.4

100.0

Missing System

88

17.6

Total

500

100.0

Ekushey Television (ETV) was the first private terrestrial channel in Bangladesh. Official transmission began on April 14, 2000, after a very short time of transmission it became the voice of the nation and the most popular TV channel in Bangladesh through its news and other innovative programs. However, it was closed down on August 29, 2002, when Managing Director Simon Dring and three other executives were charged with fraud. Dring, a British journalist, had his visa and work permit cancelled.

However, permission for the station to continue transmission once more was granted on April 14, 2005, and transmission was resumed, on December 1, 2006. Its official transmission started 29 March 2007 and, started 24 hour transmission on June 1.

ETV

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 0

1

.2

.3

.3

1

20

4.0

5.0

5.3

2

19

3.8

4.8

10.0

3

38

7.6

9.5

19.5

4

54

10.8

13.5

33.0

5

56

11.2

14.0

47.0

6

57

11.4

14.3

61.3

7

63

12.6

15.8

77.0

8

48

9.6

12.0

89.0

9

28

5.6

7.0

96.0

10

16

3.2

4.0

100.0

Total

400

80.0

100.0

Missing System

100

20.0

Total

500

100.0

Islamic TV

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 0

2

.4

.5

.5

1

6

1.2

1.6

2.2

2

8

1.6

2.2

4.4

3

10

2.0

2.7

7.1

4

19

3.8

5.2

12.3

5

25

5.0

6.8

19.1

6

30

6.0

8.2

27.2

7

39

7.8

10.6

37.9

8

58

11.6

15.8

53.7

9

78

15.6

21.3

74.9

10

92

18.4

25.1

100.0

Total

367

73.4

100.0

Missing System

133

26.6

Total

500

100.0

Channel One is a Bengali language satellite television channel from Bangladesh. It started broadcasting from Dhaka on 24 January2006. [1]

It is owned by the Masud Entertainment Limited, a sister concern of One Group.

This third generation television channel is the 8th private television in Bangladesh. This is an infotainment channel by nature. Its office is in Gulshan of Dhaka city. News times are 8 am, 12 pm, 2.30 pm, 6.30 pm, 7.30 pm, 10.00 pm, 12.30 am and 3.00 am in Bangladesh Time.

The channel’s journalists include Saiful Hasan, Saiful A Chowdhury, Shujon Mehedi, Shamim Al Amin and K U Biplob. Its producers include AKM Nazim, MAK Tuhin, Rana Islam and Iqbal Khokon. It uses final cut pro machines for video editing, and is the only channel that uses ENPS for news networking.

Channel One

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 0

1

.2

.2

.2

1

13

2.6

3.1

3.4

2

20

4.0

4.8

8.2

3

45

9.0

10.9

19.1

4

56

11.2

13.5

32.6

5

60

12.0

14.5

47.1

6

49

9.8

11.8

58.9

7

63

12.6

15.2

74.2

8

49

9.8

11.8

86.0

9

45

9.0

10.9

96.9

10

13

2.6

3.1

100.0

Total

414

82.8

100.0

Missing System

86

17.2

Total

500

100.0

Correlation Matrix

   

fa1

fa2

fa3

fa4

fa5

fa6

fa7

fa8

fa9

fa10

fa11

Correlation fa1

1.000

.178

.000

.026

-.018

.064

.153

.158

.187

.015

-.048

  fa2

.178

1.000

-.002

.101

.037

.036

.103

.084

.125

.082

.004

  fa3

.000

-.002

1.000

-.097

.664

.751

-.071

-.079

-.102

-.123

.019

  fa4

.026

.101

-.097

1.000

-.088

-.098

.150

.180

.183

.056

-.052

  fa5

-.018

.037

.664

-.088

1.000

.687

-.012

-.060

-.055

-.068

.017

  fa6

.064

.036

.751

-.098

.687

1.000

-.062

-.107

-.092

-.111

.048

  fa7

.153

.103

-.071

.150

-.012

-.062

1.000

.166

.314

.194

-.025

  fa8

.158

.084

-.079

.180

-.060

-.107

.166

1.000

.300

.226

.053

  fa9

.187

.125

-.102

.183

-.055

-.092

.314

.300

1.000

.182

-.046

  fa10

.015

.082

-.123

.056

-.068

-.111

.194

.226

.182

1.000

.162

  fa11

-.048

.004

.019

-.052

.017

.048

-.025

.053

-.046

.162

1.000

The positive value that the two variables have a correlation. The maximum value that can be extracted is 1 which states the strongest relation among the variables.

KMO and Bartlett’s Test:

Kaiser-Meyer-Olkin Measure of Sampling Adequacy. .715
Bartlett’s Test of Sphericity Approx. Chi-Square 971.211
df 55
Sig. .000

The suitability of data for factor analysis depends on two measures: KMO index and Bartlett’s test. To be a suitable data, a data need to have a KMO index with minimum value of 0.6 and the Bartlett’s test for sphericity should be less than less than .05.

The data out here have KMO index value of .715 which is less than 0.6 but close enough to 0.6, and the Bartlett’s test for sphericity value is .000 which is less than.05.

Therefore, we can go for the Factor extraction.

Communalities

Initial

Extraction

fa1

1.000

.701

fa2

1.000

.812

fa3

1.000

.811

fa4

1.000

.827

fa5

1.000

.768

fa6

1.000

.830

fa7

1.000

.476

fa8

1.000

.422

fa9

1.000

.560

fa10

1.000

.569

fa11

1.000

.708

Extraction Method: Principal Component Analysis.

Total Variance Explained

Component Initial Eigenvalues Extraction Sums of Squared Loadings
Total % of Variance Cumulative % Total % of Variance Cumulative %
1 2.544 23.130 23.130 2.544 23.130 23.130
2 1.846 16.777 39.907 1.846 16.777 39.907
3 1.175 10.686 50.593 1.175 10.686 50.593
4 .998 9.072 59.666 .998 9.072 59.666
5 .920 8.368 68.033 .920 8.368 68.033
6 .851 7.733 75.766
7 .774 7.037 82.802
8 .686 6.238 89.040
9 .623 5.664 94.704
10 .342 3.105 97.809
11 .241 2.191 100.000

Extraction Method: Principal Component Analysis.

By the Kaiser’s criterion, the factors with eigenvalue equal to or greater to 1 are retained for further investigation. The eigenvalue of a factor represents the amount of the variance explained by that factor.

Out here, there are four components with eigenvalue greater to 1.

Therefore, these values will be taken for further analysis.

As we know that Kaiser’s criterion results in the retention of too many factors, therefore we need to go through Scree test. By the Scree test the factors above the elbow, or break in the plot, as the factors are considered to be the factors that contribute the most to the explanation of the variance in the set.

In this case, there are two factors that are above the elbow.

Component Matrix (a)

Component

1

2

3

4

5

fa1

-.088

.449

-.343

.556

-.253

fa2

-.066

.406

-.164

.548

.562

fa3

.851

.278

.018

-.098

.000

fa4

-.271

.323

-.190

-.480

.619

fa5

.801

.332

.047

-.116

.000

fa6

.856

.312

.015

-.015

.007

fa7

-.258

.550

-.043

-.168

-.278

fa8

-.312

.529

.171

-.121

-.034

fa9

-.332

.609

-.094

-.161

-.208

fa10

-.293

.367

.586

-.006

-.070

fa11

.030

.041

.780

.256

.177

Extraction Method: Principal Component Analysis. a 5 components

News

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

226

45.2

52.4

52.4

2

42

8.4

9.7

62.2

3

25

5.0

5.8

68.0

4

21

4.2

4.9

72.9

5

19

3.8

4.4

77.3

6

5

1.0

1.2

78.4

7

13

2.6

3.0

81.4

8

15

3.0

3.5

84.9

9

11

2.2

2.6

87.5

10

7

1.4

1.6

89.1

11

8

1.6

1.9

91.0

12

4

.8

.9

91.9

13

5

1.0

1.2

93.0

14

4

.8

.9

94.0

15

2

.4

.5

94.4

16

3

.6

.7

95.1

17

3

.6

.7

95.8

18

4

.8

.9

96.8

19

1

.2

.2

97.0

20

2

.4

.5

97.4

21

4

.8

.9

98.4

23

2

.4

.5

98.8

24

1

.2

.2

99.1

25

1

.2

.2

99.3

27

3

.6

.7

100.0

Total

431

86.2

100.0

Missing System

69

13.8

Total

500

100.0

  Statistics:

Bangla Cinema:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

49

9.8

13.4

13.4

2

12

2.4

3.3

16.7

3

21

4.2

5.8

22.5

4

19

3.8

5.2

27.7

5

28

5.6

7.7

35.3

6

21

4.2

5.8

41.1

7

20

4.0

5.5

46.6

8

13

2.6

3.6

50.1

9

4

.8

1.1

51.2

10

15

3.0

4.1

55.3

11

9

1.8

2.5

57.8

12

11

2.2

3.0

60.8

13

5

1.0

1.4

62.2

14

8

1.6

2.2

64.4

15

7

1.4

1.9

66.3

16

15

3.0

4.1

70.4

17

11

2.2

3.0

73.4

18

7

1.4

1.9

75.3

19

6

1.2

1.6

77.0

20

12

2.4

3.3

80.3

21

12

2.4

3.3

83.6

22

7

1.4

1.9

85.5

23

5

1.0

1.4

86.8

24

9

1.8

2.5

89.3

25

8

1.6

2.2

91.5

26

11

2.2

3.0

94.5

27

20

4.0

5.5

100.0

Total

365

73.0

100.0

Missing System

135

27.0

Total

500

100.0

Drama

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

67

13.4

15.6

15.6

2

99

19.8

23.1

38.7

3

80

16.0

18.6

57.3

4

43

8.6

10.0

67.4

5

35

7.0

8.2

75.5

6

17

3.4

4.0

79.5

7

15

3.0

3.5

83.0

8

10

2.0

2.3

85.3

9

9

1.8

2.1

87.4

10

10

2.0

2.3

89.7

11

7

1.4

1.6

91.4

12

8

1.6

1.9

93.2

13

6

1.2

1.4

94.6

14

4

.8

.9

95.6

15

4

.8

.9

96.5

16

5

1.0

1.2

97.7

18

2

.4

.5

98.1

19

1

.2

.2

98.4

20

2

.4

.5

98.8

22

1

.2

.2

99.1

23

2

.4

.5

99.5

25

1

.2

.2

99.8

27

1

.2

.2

100.0

Total

429

85.8

100.0

Missing System

71

14.2

Total

500

100.0

Drama Serial

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

50

10.0

12.1

12.1

2

104

20.8

25.2

37.3

3

56

11.2

13.6

50.8

4

48

9.6

11.6

62.5

5

25

5.0

6.1

68.5

6

24

4.8

5.8

74.3

7

18

3.6

4.4

78.7

8

12

2.4

2.9

81.6

9

10

2.0

2.4

84.0

10

10

2.0

2.4

86.4

11

5

1.0

1.2

87.7

12

6

1.2

1.5

89.1

13

8

1.6

1.9

91.0

14

2

.4

.5

91.5

15

3

.6

.7

92.3

16

4

.8

1.0

93.2

17

6

1.2

1.5

94.7

18

1

.2

.2

94.9

19

5

1.0

1.2

96.1

21

3

.6

.7

96.9

22

3

.6

.7

97.6

23

3

.6

.7

98.3

25

3

.6

.7

99.0

26

3

.6

.7

99.8

27

1

.2

.2

100.0

Total

413

82.6

100.0

Missing System

87

17.4

Total

500

100.0

Entertainment Magazine Program:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

21

4.2

5.1

5.1

2

28

5.6

6.7

11.8

3

62

12.4

14.9

26.7

4

61

12.2

14.7

41.4

5

60

12.0

14.5

55.9

6

37

7.4

8.9

64.8

7

27

5.4

6.5

71.3

8

17

3.4

4.1

75.4

9

18

3.6

4.3

79.8

10

17

3.4

4.1

83.9

11

9

1.8

2.2

86.0

12

7

1.4

1.7

87.7

13

8

1.6

1.9

89.6

14

7

1.4

1.7

91.3

15

5

1.0

1.2

92.5

16

4

.8

1.0

93.5

17

5

1.0

1.2

94.7

18

3

.6

.7

95.4

19

2

.4

.5

95.9

20

3

.6

.7

96.6

21

3

.6

.7

97.3

23

3

.6

.7

98.1

24

1

.2

.2

98.3

25

4

.8

1.0

99.3

26

2

.4

.5

99.8

27

1

.2

.2

100.0

Total

415

83.0

100.0

Missing System

85

17.0

Total

500

100.0

News Related Magazine Program:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

4

.8

1.3

1.3

2

8

1.6

2.5

3.8

3

22

4.4

7.0

10.8

4

21

4.2

6.7

17.5

5

17

3.4

5.4

22.9

6

21

4.2

6.7

29.6

7

20

4.0

6.4

36.0

8

13

2.6

4.1

40.1

9

12

2.4

3.8

43.9

10

16

3.2

5.1

49.0

11

15

3.0

4.8

53.8

12

11

2.2

3.5

57.3

13

6

1.2

1.9

59.2

14

13

2.6

4.1

63.4

15

18

3.6

5.7

69.1

16

7

1.4

2.2

71.3

17

7

1.4

2.2

73.6

18

8

1.6

2.5

76.1

19

14

2.8

4.5

80.6

20

12

2.4

3.8

84.4

21

11

2.2

3.5

87.9

22

12

2.4

3.8

91.7

23

5

1.0

1.6

93.3

24

8

1.6

2.5

95.9

25

6

1.2

1.9

97.8

26

5

1.0

1.6

99.4

27

2

.4

.6

100.0

Total

314

62.8

100.0

Missing System

186

37.2

Total

500

100.0

Religious Program:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

7

1.4

2.2

2.2

2

26

5.2

8.0

10.2

3

27

5.4

8.3

18.5

4

23

4.6

7.1

25.6

5

17

3.4

5.2

30.9

6

22

4.4

6.8

37.7

7

10

2.0

3.1

40.7

8

8

1.6

2.5

43.2

9

13

2.6

4.0

47.2

10

11

2.2

3.4

50.6

11

10

2.0

3.1

53.7

12

14

2.8

4.3

58.0

13

6

1.2

1.9

59.9

14

5

1.0

1.5

61.4

15

6

1.2

1.9

63.3

16

10

2.0

3.1

66.4

17

10

2.0

3.1

69.4

18

16

3.2

4.9

74.4

19

12

2.4

3.7

78.1

20

13

2.6

4.0

82.1

21

6

1.2

1.9

84.0

22

8

1.6

2.5

86.4

23

6

1.2

1.9

88.3

24

8

1.6

2.5

90.7

25

6

1.2

1.9

92.6

26

8

1.6

2.5

95.1

27

16

3.2

4.9

100.0

Total

324

64.8

100.0

Missing System

176

35.2

Total

500

100.0

Cooking Program:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

6

1.2

1.9

1.9

2

6

1.2

1.9

3.7

3

9

1.8

2.8

6.5

4

9

1.8

2.8

9.3

5

25

5.0

7.7

17.0

6

17

3.4

5.2

22.2

7

12

2.4

3.7

25.9

8

12

2.4

3.7

29.6

9

14

2.8

4.3

34.0

10

7

1.4

2.2

36.1

11

7

1.4

2.2

38.3

12

10

2.0

3.1

41.4

13

12

2.4

3.7

45.1

14

8

1.6

2.5

47.5

15

10

2.0

3.1

50.6

16

6

1.2

1.9

52.5

17

12

2.4

3.7

56.2

18

9

1.8

2.8

59.0

19

10

2.0

3.1

62.0

20

20

4.0

6.2

68.2

21

13

2.6

4.0

72.2

22

15

3.0

4.6

76.9

23

16

3.2

4.9

81.8

24

9

1.8

2.8

84.6

25

9

1.8

2.8

87.3

26

18

3.6

5.6

92.9

27

23

4.6

7.1

100.0

Total

324

64.8

100.0

Missing System

176

35.2

Total

500

100.0

                         

Talk Show

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

2

.4

.6

.6

2

16

3.2

4.9

5.5

3

24

4.8

7.4

12.9

4

22

4.4

6.8

19.7

5

21

4.2

6.5

26.2

6

25

5.0

7.7

33.8

7

18

3.6

5.5

39.4

8

14

2.8

4.3

43.7

9

13

2.6

4.0

47.7

10

14

2.8

4.3

52.0

11

18

3.6

5.5

57.5

12

15

3.0

4.6

62.2

13

12

2.4

3.7

65.8

14

7

1.4

2.2

68.0

15

8

1.6

2.5

70.5

16

3

.6

.9

71.4

17

6

1.2

1.8

73.2

18

9

1.8

2.8

76.0

19

5

1.0

1.5

77.5

20

8

1.6

2.5

80.0

21

7

1.4

2.2

82.2

22

7

1.4

2.2

84.3

23

8

1.6

2.5

86.8

24

9

1.8

2.8

89.5

25

12

2.4

3.7

93.2

26

12

2.4

3.7

96.9

27

10

2.0

3.1

100.0

Total

325

65.0

100.0

Missing System

175

35.0

Total

500

100.0

Band Show Program:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

4

.8

1.2

1.2

2

9

1.8

2.7

4.0

3

7

1.4

2.1

6.1

4

11

2.2

3.4

9.5

5

15

3.0

4.6

14.0

6

24

4.8

7.3

21.3

7

12

2.4

3.7

25.0

8

16

3.2

4.9

29.9

9

16

3.2

4.9

34.8

10

8

1.6

2.4

37.2

11

14

2.8

4.3

41.5

12

13

2.6

4.0

45.4

13

17

3.4

5.2

50.6

14

10

2.0

3.0

53.7

15

14

2.8

4.3

57.9

16

9

1.8

2.7

60.7

17

14

2.8

4.3

64.9

18

11

2.2

3.4

68.3

19

14

2.8

4.3

72.6

20

4

.8

1.2

73.8

21

8

1.6

2.4

76.2

22

13

2.6

4.0

80.2

23

12

2.4

3.7

83.8

24

8

1.6

2.4

86.3

25

12

2.4

3.7

89.9

26

12

2.4

3.7

93.6

27

21

4.2

6.4

100.0

Total

328

65.6

100.0

Missing System

172

34.4

Total

500

100.0

Tele Film:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

12

2.4

3.1

3.1

2

7

1.4

1.8

4.9

3

23

4.6

5.9

10.8

4

30

6.0

7.7

18.5

5

22

4.4

5.6

24.1

6

39

7.8

10.0

34.1

7

28

5.6

7.2

41.3

8

28

5.6

7.2

48.5

9

25

5.0

6.4

54.9

10

19

3.8

4.9

59.7

11

19

3.8

4.9

64.6

12

16

3.2

4.1

68.7

13

16

3.2

4.1

72.8

14

15

3.0

3.8

76.7

15

17

3.4

4.4

81.0

16

14

2.8

3.6

84.6

17

8

1.6

2.1

86.7

18

6

1.2

1.5

88.2

19

12

2.4

3.1

91.3

20

2

.4

.5

91.8

21

7

1.4

1.8

93.6

22

3

.6

.8

94.4

23

3

.6

.8

95.1

24

9

1.8

2.3

97.4

25

1

.2

.3

97.7

26

4

.8

1.0

98.7

27

5

1.0

1.3

100.0

Total

390

78.0

100.0

Missing System

110

22.0

Total

500

100.0

 

Correlation Matrix

 

RON1

RON2

RON3

RON4

RON5

RON6

RON7

RON8

RON9

RON10

Correlation Bangla Vision

1.000

.177

.070

.140

.163

.133

.224

.044

.157

.307

BTV

.177

1.000

-.020

.047

-.116

.173

.181

.095

.290

.172

ATN

.070

-.020

1.000

.158

.137

.053

-.008

.164

.004

.000

Channel i

.140

.047

.158

1.000

.218

.040

.110

.179

.117

.190

NTV

.163

-.116

.137

.218

1.000

.045

.144

.038

.115

.190

Baishakhi

.133

.173

.053

.040

.045

1.000

.290

.131

.210

.241

RTV

.224

.181

-.008

.110

.144

.290

1.000

.205

.147

.292

ETV

.044

.095

.164

.179

.038

.131

.205

1.000

.080

.151

Islamic TV

.157

.290

.004

.117

.115

.210

.147

.080

1.000

.172

Channel One

.307

.172

.000

.190

.190

.241

.292

.151

.172

1.000

KMO and Bartlett’s Test

 

 

 

 

 

Kaiser-Meyer-Olkin Measure of Sampling Adequacy.

.693

Bartlett’s Test of Sphericity Approx. Chi-Square

329.400

df

45

Sig.

.000

Communalities:

Initial

Extraction

Bangla Vision (RON 1)

1.000

.477

BTV (RON 2)

1.000

.713

ATN (RON 3)

1.000

.716

Channel I (RON 4)

1.000

.628

NTV (RON 5)

1.000

.704

Baishakhi (RON 5)

1.000

.732

RTV (RON 6)

1.000

.601

ETV (RON 7)

1.000

.749

Islamic TV (RON 8)

1.000

.671

Channel One (RON 10)

1.000

.561

Extraction Method: Principal Component Analysis

Total Variance Explained:

Component

Initial Eigenvalues

Extraction Sums of Squared Loadings

Total

% of Variance

Cumulative %

Total

% of Variance

Cumulative %

1

2.297

22.974

22.974

2.297

22.974

22.974

2

1.336

13.355

36.329

1.336

13.355

36.329

3

1.076

10.758

47.087

1.076

10.758

47.087

4

.972

9.720

56.808

.972

9.720

56.808

5

.871

8.709

65.516

.871

8.709

65.516

6

.854

8.543

74.059

7

.722

7.223

81.283

8

.677

6.773

88.055

9

.630

6.300

94.355

10

.565

5.645

100.000

Extraction Method: Principal Component Analysis.                                

Component Matrix (a)

Component

1

2

3

4

5

ron1

.546

.011

-.368

.131

-.162

ron2

.436

-.536

.224

.398

-.164

ron3

.180

.548

.448

.213

.369

ron4

.419

.487

.062

.272

-.370

ron5

.356

.564

-.432

.016

.268

ron6

.525

-.259

.147

-.315

.519

ron7

.611

-.125

-.026

-.459

-.026

ron8

.397

.195

.640

-.252

-.283

ron9

.498

-.266

.005

.521

.284

ron10

.648

-.013

-.259

-.180

-.203

Extraction Method: Principal Component Analysis.

a 5 components extracted.

  • 7 – 9 am ……………………………….. (1)
  • 9 am – 1 pm ………………………….. (2)
  • 1 – 5 pm ……………………………….. (3)
  • 5 – 7 pm ……………………………….. (4)
  • 7 – 8.5 pm …………………………….. (5)
  • 8.5 – 10 pm …………………………… (6)
  • 10 – 12 pm ……………………………. (7)
  • After 12 am …………………………… (8)

Statistics:

N

Valid

482

Missing

18

Mode

6

Std. Deviation

1.151

Range

7

Preferable Time:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

2

.4

.4

.4

2

5

1.0

1.0

1.5

3

21

4.2

4.4

5.8

4

26

5.2

5.4

11.2

5

55

11.0

11.4

22.6

6

238

47.6

49.4

72.0

7

125

25.0

25.9

97.9

8

10

2.0

2.1

100.0

Total

482

96.4

100.0

Missing System

18

3.6

Total

500

100.0

Time of Watching Bangladeshi Channels:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid

1

99

19.8

20.5

20.5

2

140

28.0

29.0

49.6

3

126

25.2

26.1

75.7

4

98

19.6

20.3

96.1

5

19

3.8

3.9

100.0

Total

482

96.4

100.0

Missing

System

18

3.6

Total

500

100.0

Foreign Movie (Action, science fiction, comedy etc)

      Sports Channel

      Talent Hunting Program

      Children Related Program

      Comedy Type Program

      Adventure Program

      Computer / Technological Program

      Cultural Program

      Award Show

      Science Related Program

      Animal Life Program

Statistics:

N Valid

500

Missing

0

Mode

4

Variance

1.627

Age:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid 1

1

.2

.2

.2

2

9

1.8

1.8

2.0

3

46

9.2

9.2

11.2

4

240

48.0

48.0

59.2

5

96

19.2

19.2

78.4

6

53

10.6

10.6

89.0

7

38

7.6

7.6

96.6

8

17

3.4

3.4

100.0

Total

500

100.0

100.0

  • Illiterate ……………………………………………………… (1)
  • Literate ……………………………………………………. (2)
  • Secondary Level ……………(Bangali)………………….(3)
  • Ordinary Level …………………………………………… (4)
  • Higher Secondary Level ……..(Bangali)…………….. (5)
  • Advanced Level ………………………………………….. (6)
  • Under Graduate …………………………………………..(7)
  • Post Graduate ……………………………………………..(8)

Statistics

                                                Edu

N Valid

500

Missing

0

Std. Error of Mean

.099

Std. Deviation

2.216

Range

7

Minimum

1

Education:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid

1

16

3.2

3.2

3.2

2

55

11.0

11.0

14.2

3

68

13.6

13.6

27.8

4

4

.8

.8

28.6

5

87

17.4

17.4

46.0

6

5

1.0

1.0

47.0

7

165

33.0

33.0

80.0

8

100

20.0

20.0

100.0

Total

500

100.0

100.0

      1 Person …………………………. (1)

      2 – 3 Person ………………………(2)

      4 – 5 Person ………………………(3)

      6 – 8 Person ………………………(4)

      8 + …………………………………. (5)

Statistics:

N Valid

498

Missing

2

Mode

3

Range

4

Percentiles 25

3.00

50

3.00

75

4.00

Family Member:

Frequency

Percent

Valid Percent

Cumulative Percent

Valid

1

3

.6

.6

.6

2

71

14.2

14.3

14.9

3

283

56.6

56.8

71.7

4

118

23.6

23.7

95.4

5

23

4.6

4.6

100.0

Total

498

99.6

100.0

Missing

System

2

.4

Total

500

100.0

CONCLUSION:

Television is playing a good role in our country. Though several television channels are operating in our country all of them are not providing same services. They have to count every nick of time in news presenting and other programs presenting. Analyzing the urban based electronic media preference the following result can be summarized in conclusion—

      As per the survey done through structured questionnaire 95.6 % of the watch Bangladeshi TV channels and the rests of 4.4 % do not watch Bangladeshi TV channels.

      Out of the 500 respondents, who participated in the survey, most of them turned out to be audiences of NTV and their first preference was also NTV as it provides realistic news and quality programs.

      Audiences spend about 60 % time in seeing Bangladeshi channels.

      Preferable time slot of the audiences is 8. 30 pm to 10 pm.

      Most of the audiences mentioned that news is their first preference.

      Most of the audiences stated that NTV are presenting realistic news.

      According to the audiences magazine program Ittady is their most favourite program.

      Talkshow programs are the most disliked by the audiences.

      Audiences want to watch programs with clear picture and sound.

      Audiences want to watch programs that started at the mentioned time.

      Audiences dislike govt. follower programs

      So much commercial Ad is not expected by the audience.

      TV channels involved in public welfare are expected by the audiences.

The 10 television companies those are broadcasting in our country are very alluring and competitive. But to be a realistic and preferable channel in context of the audiences they have to provide according to the demand of the audiences. These TV channels have to provide such programs that the audiences want to watch. TV channels should not concern only about programs but also preferable time slot for the target audiences should be concerned by those TV channels.

We are very pleased to have such a wonderful experience in getting this report to existence, and we feel inculcated to do such a report on such an interesting topic. This study will help us to explore the preferences of the audiences of the TV channels.

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EEEScience

Report on Digital Communication System

Executive Summery

In this project, Digital Communication System using QPSK Modulation is analyzed and simulated. The main aim of the thesis is to achieve the best digital communication using QPSK modulation and reduce the effect of noises in the communication channel. This thesis details the software implementation of a modern digital communication system and digital modulation methods. The digital modulation schemes considered here include both baseband and Quadrature Phase Shift Keying (QPSK) techniques. The proposed communication system will serve as a practical tool useful for simulating the transmission of any digital data. We use the MATLAB programming to simulate the communication project and simulated portion are attached and discuss briefly. There are some steps of any digital communication model. We discuss each of the steps using necessary diagram and try to understand the reader nicely about digital communication system where we told about Linear Predictive Coding (LPC) in source coding, PLL and all the modulation technique specially the Quadrature Phase Shift Keying (QPSK) in detail for using in the digital communication. The proposed communication system will serve as a practical tool useful for simulating the transmission of any digital data. The various modules of the system include analog to digital converters, digital to analog converters, encoders/decoders and modulators/demodulators. The results show the viability of a QPSK modulated digital communications link.

INTRODUCTION

Communication has been one of the deepest needs of the human race throughout recorded history. It is essential to forming social unions, to educating the young, and to expressing a myriad of emotions and needs. Good communication is central to a civilized society.

The various communication disciplines in engineering have the purpose of providing technological aids to human communication. One could view the smoke signals and drum rolls of primitive societies as being technological aids to communication, but communication technology as we view it today became important with telegraphy, then telephony, then video, then computer communication, and today the amazing mixture of all of these in inexpensive, small portable devices.

Initially these technologies were developed as separate networks and were viewed as having little in common. As these networks grew, however, the fact that all parts of a given network had to work together, coupled with the fact that different components were developed at different times using different design methodologies, caused an increased focus on the underlying principles and architectural understanding required for continued system evolution.

The possible configurations of the link are numerous, so focus was maintained on a typical system that might be used in satellite communications. For this reason convolution channel coders and QPSK modulation were chosen. Additionally, channel effects were primarily modeled as the combination of band laired additive white Gaussian noise (AWGN) and signal attenuation. The results of this link on speech transmission show the various gains and tradeoffs that are realized as data passes through the entire system; the quantitative performance is measured by the probability of bit error, Pe, and the effect various signal to noise ratios have on this probability.

The idea of converting an analog source output to a binary sequence was quite revolutionary in 1948, and the notion that this should be done before channel processing was even more revolutionary. By today, with digital cameras, digital video, digital voice, etc., the idea of digitizing any kind of source is commonplace even among the most technophobic. The notion of a binary interface before channel transmission is almost as commonplace. For example, we all refer to the speed of our internet connection in bits per second.

There are a number of reasons why communication systems now usually contain a binary interface between source and channel (i.e., why digital communication systems are now standard). These will be explained with the necessary qualifications later, but briefly they are as follows:

– Digital hardware has become so cheap, reliable, and miniaturized, that digital interfaces are eminently practical.

– A standardized binary interface between source and channel simplifies implementation and understanding, since source coding/decoding can be done independently of the channel, and, similarly, channel coding/decoding can be done independently of the source.

This thesis studies the Digital Communication System for Quadrature Phase Shift Keying (QPSK) modulation used in digital communications. Software implementation is performed in the MATLAB programming languages and consists of separately coding and interfacing the various functions of the system. By modularizing the various functions which are performed on the data from source to destination, it becomes convenient to change individual sections of the link and model the effects of different transmission conditions on data as it is passed through the channel. The modules of the link include source encoders/decoders, channel encoders/decoders, modulators/demodulators, and channel effects.

ORGANIZATION OF THE THESIS

We use Quadrature Phase Shift Keying (QPSK) Technique in the Digital communication system for better signal transmit and receive in the communication model.

In chapter one, the use and necessary of digital communication in our life has been presented in brief.

In chapter two, we describe the basic digital communication system and channel model which is use in this thesis.

In chapter three, source coding is described briefly. The source encoder is responsible for producing the digital information which will be manipulated by the remainder of the system.

In chapter four, we describe the channel coding in brief and the goal of channel coding is told which allows the detector at the receiver to detect and/or correct errors which might have been introduced during transmission. We use AWGN in the channel coding and it is also presented.

In chapter five, we describe the modulation technique of the digital communication in which Quadrature Phase Shift Keying (QPSK) is described elaborately.

In chapter six, the channel equalization and adaptive filtering are presented in brief.

In chapter seven, we described the demodulation of the communication model used in the thesis.

In chapter eight, we demonstrate the simulation result of QPSK modulation. The software for the simulation, we use the MATLAB platform.

A conclusion was made in chapter nine.

Literature Review

Chapter 2

DIGITAL COMMUNITION MODEL

In this chapter, we describe the basic digital communication system and channel model which is use in this thesis. The model is a simple model of digital communication system. The model is broken into its constituent functions or modules, and each of these is in turn described in terms of its affects on the data and the system. Since this model comprises the entire system, both the source coding and channel equalization are briefly described. In chapters 3 through 8, these two areas will be covered in detail, and the specific algorithms and methods used in the software implementation will be addressed in detail.

We organize this chapter as follows. First, we review some basic notions from digital communications. We present one basic model of digital communication system. We then talk about source encoding and decoding, channel encoding and decoding, modulation, digital interface and channel effects.

2.1 DIGITAL COMMUNICATION

Communication systems that first convert the source output into a binary sequence and then convert that binary sequence into a form suitable for transmission over particular physical media such as cable, twisted wire pair, optical fiber, or electromagnetic radiation through space.

Digital communication systems, by definition,are communication systems that use such a digital sequence as an interface between the source and the channel input (and similarly between the channel output and final destination).

digital-communication-module
Figure 2.1 in the basic digital communication model the first three blocks of the diagram (source encoder, channel encoder, and modulator) together comprise the transmitter .The source represents the message to be transmitted which includes speech, video, image, or text data among others. If the information has been acquired in analog form, it must be converted into digitized form to make our communication easier. This analog to digital conversion (ADC) is accomplished in the source encoder block. Placing a binary interface between source and channel. The source encoder converts the source output to a binary sequence and the channel encoder (often called a modulator) processes the binary sequence for transmission over the channel.

The last three blocks consisting of detector/demodulator, channel decoder, and source decoder form the receiver. The destination represents the client waiting for the information. This might include a human or a storage device or another processing station. In any case, the source decoder’s responsibility is to recover the information from the channel decoder and to transform it into a form suitable for the destination. This transformation includes digital to analog conversion (DAC) if the destination is a human waiting to hem or view the information or if it is an analog storage device. If the destination is a digital storage device, the information will be kept in its digital state without DAC. The channel decoder (demodulator) recreates the incoming binary sequence (hopefully reliably), and the source decoder recreates the source output.

2.2 SOURCE ENCODING AND ECODING

The source encoder and decoder in Figure 2.1 have the function of converting the input from its original form into a sequence of bits. As discussed before, the major reasons for this almost universal conversion to a bit sequence are as follows: inexpensive digital hardware, standardized interfaces, layering, and the source/channel separation theorem.
The simplest source coding techniques apply to discrete sources and simply involve representing each successive source symbol by a sequence of binary digits. For example, letters from the 27symbol English alphabet (including a space symbol) may be encoded into 5-bit blocks. Since there are 32 distinct 5-bit blocks, each letter may be mapped into a distinct 5-bit block with a few blocks left over for control or other symbols. Similarly, upper-case letters, lower-case letters, and a great many special symbols may be converted into 8-bit blocks (“bytes”) using the standard ASCII code.

For example the input symbols might first be segmented into m – tupelos, which are then mapped into blocks of binary digits. More generally yet, the blocks of binary digits can be generalized into variable-length sequences of binary digits. We shall find that any given discrete source, characterized by its alphabet and probabilistic description, has a quantity called entropy associated with it. Shannon showed that this source entropy is equal to the minimum number of binary digits per source symbol required to map the source output into binary digits in such a way that the source symbols may be retrieved from the encoded sequence.

Some discrete sources generate finite segments of symbols, such as email messages, that are statistically unrelated to other finite segments that might be generated at other times. Other discrete sources, such as the output from a digital sensor, generate a virtually unending sequence of symbols with a given statistical characterization. The simpler models of Chapter 2 will correspond to the latter type of source, but the discussion of universal source coding is sufficiently general to cover both types of sources, and virtually any other kind of source.

The most straight forward approach to analog source coding is called analog to digital (A/D) conversion.

2.3 CHANNEL ENCODING AND DECODING

The channel encoder and decoder box in Figure 2.1 has the function of mapping the binary sequence at the source/channel interface into a channel waveform.

One of the advantages of digital communications over analog communications is its robustness during transmission. Due to the two state nature of binary data (i.e. either a 1 or a 0), it is not as susceptible to noise or distortion as analog data. While even the slightest noise will corrupt an analog signal, small mounts of noise will generally not be enough to change the state of a digital signal from I to 0 or vice versa and will in fact be ‘ignored’ at the receiver while the correct information is accurately recovered.
Nevertheless, larger amounts of noise and interference can cause a signal to be demodulated incorrectly resulting in a bit stream with errors at the destination. Unlike an analog system, a digital system can reduce the effect of noise by employing an error control mechanism which is used prior to modulation. The channel encoder performs this error control by systematically introducing redundancy into the information bit stream after it has been source encoded but prior to its transmission. This redundancy can then be used by the receiver to resolve errors that might occur during transmission due to noise or interference.

The channel decoder performs the task of decoding the received coded bit stream by means of a decoding algorithm tailored for the encoding scheme. Error control of this variety that allows a receiver to resolve errors in a bit stream by decoding redundant information introduced at the transmitter is known as Forward Error Correction (FEC). The price paid for employing FEC is the increased bit rate and complexity of the transmitter and receiver.

2.4 MODULATION

The digital modulator serves as an interface between the transmitter and the channel. It serves the purpose of mapping the binary digital information it receives into waveforms compatible with the channel. In baseband modulation, the output waveforms we simple voltage pulses which take predefined values corresponding to a 1 or 0. However, many channels, such as a satellite channel, are not suited for backhand communication and require the incoming data to be modulated to a higher frequency, referred to as the carrier frequency, so it can be converted to an electromagnetic wave that will propagate through space to its destination ( a satellite or a ,round station) This type of modulation, known as band pass modulation, varies one of the following three parameters of the carrier frequency based on the incoming digital bit stream: amplitude, frequency or phase. These modulation types are commonly known as Amplitude Shift Keying (ASK). Frequency Shift Keying (FSK) and Phase Shift Keying (PSK) respectively.

The digital detector/demodulator reverses the process and extracts the binary baseband information from the received modulated signal which has been subjected to noise, interference, loss, and other distortions. The demodulator produces a sequence of binary values which are estimates of the transmitted data and passes it on to the channel decoder.

2.5 DIGITAL INTERFACE

The interface between the source coding layer and the channel coding layer is a sequence of bits. However, this simple characterization does not tell the whole story. The major complicating factors are as follows:

– Unequal rates: The rate at which bits leave the source encoder is often not perfectly matched to the rate at which bits enter the channel encoder.

– Errors: Source decoders are usually designed to decode an exact replica of the encoded sequence, but the channel decoder makes occasional errors.

– Networks: Encoded source outputs are often sent over networks, traveling serially over several channels; each channel in the network typically also carries the output from a number of different source encoders.

The first two factors above appear both in point-to-point communication systems and in networks. They are often treated in an ad hoc way in point-to-point systems, whereas they must be treated in a standardized way in networks. The third factor, of course, must also be treated in a standardized way in networks.

2.6 CHANNEL EFFECTS

During transmission, the signal undergoes various degrading and distortion effects as it passes through the medium from the transmitter to the receiver. This medium is commonly referred to as the channel. Channel effects include, but are not limited to, noise, interference, linear and non linear distortion and attenuation. These effects are contributed by a wide variety of sources including solar radiation, weather and signals front adjacent channels. But many of the prominent effects originate from the components in the receiver. While many of the effects can be greatly reduced by good system design, careful choice of filter parameters, and coordination of frequency spectrum usage with other users, noise and attenuation generally cannot be avoided and are the largest contributors to signal distortion.

In digital communication systems, a common quantity used to determinate whether a signal will be detected correctly is the ratio of energy per bit to spectral noise power density, Eb / No, measured at the detector. The higher the Eb, the lower the resulting bit error rate (BER), the probability of bit error, Pb Unfortunately, a high Eb demands greater power consumption at the transmitter; in some cases, it may be unfeasible to obtain a high Eb due to transmitter size or power limitations as in the case of satellite transmission.

The digital communication system described consists of an ordered grouping of various modules which operate on an input data sequence. In practice, these modules or resources are not dedicated to a single source/destination, but they me shared by multiple sources and their destinations to achieve optimum utilization.

In a digital system, the transmission bit rate is an important system resource. A given information source of bandwidth B, sampled at 2B samples/second using q bits per sample results in a data rate, R, of 2Bq bits per second. With a compression ratio C, the data rate from the source encoder is Rs = RIC bits per second. Channel coding by a factor n leads to a coded data rate of Rc = Rs n bits per second; R, is the system transmission bit rate. These bits we then used by the modulator to form the transmission waveforms which have to be accommodated within the available bandwidth. At the receiver these steps m performed in the reverse order to recover the information sequence.

Chapter 3

SOURCE CODING

In the digital communication system model described previously, the source encoder is responsible for producing the digital information which will be manipulated by the remainder of the system. After the digital signal is acquired from the analog information, the source encoder subjects it to a wide range of processing functions, the goals of which are to compactly represent the information. Speech, image, and textual information each have their own unique characteristics that require different source encoding techniques. Depending on the information source, different digital signal processing functions are implemented to remove the redundancies inherent in the given signal. The specifics of the speech compression techniques used in this thesis are detailed below.

In this chapter we describe the source coding and then its related speech compression, Linear predictive coding (LPC) and Code excited linear prediction (CELP).The use of these in digital communication in source coding. And we also describe the LPC in large as we use it in the source coding in our digital communication thesis.

3.1 SPEECH COMPRESSION

Since the frequency content of spoken language is confined to frequencies under 4000 Hz, it is reasonable to use a sampling frequency of 8000 Hz. Using 16 bit linear Pulse code modulation (PCM) as the quantization method results in a bit rate of 128 kbps. Subsequent analysis, coding, and compression of speech are performed on segments or frames of 20 to 30 ms duration.

There are two broad categories of speech coding/compression. Both categories are concerned with representing the speech with the minimum number of applicable parameters while also allowing the speech to be intelligibly reproduced; both are loss in nature.

The first category deals with waveform coders which manipulate quantities in the speech signal’s frequency representation. Typical analysis tools of waveform coders are the Discrete Fourier Transform (DFT) and the Discrete Wavelet Transform (DWT), both of which transform the time signal to its frequency domain representation. In this case, compression might potentially be achieved by retaining the frequency components with the largest magnitudes.

The second category of speech compression deals with voice coders, or vocoders for short. Vocoders attempt to represent speech as the output of a linear system driven by either periodic or random excitation sequences as shown in Figure 3.1.

basic-model-of-vocoder
A periodic impulse train or a white noise sequence, representing voiced or unvoiced speech, drives an all pole digital filter to produce the speech output. The all pole filter digital filter models the vocal tract.

Additionally, estimates of the pitch period and gain parameters are necessary for accurate reproduction of the speech. Due to the slowly changing shape of the vocal tract over time, vocoders successfully reproduce speech by modeling the vocal tract independently for each frame of speech and driving it by an estimate of a separate input excitation sequence for that frame. Most vocoders differ in performance principally based on their methods of estimating the excitation sequences.

3.2 LINEAR PREDICTIVE CODING (LPC)

Linear Predictive Coding (LPC) is one of the most powerful speech analysis techniques, and one of the most useful methods for encoding good quality speech at a low bit rate. It provides extremely accurate estimates of speech parameters, and is relatively efficient for computation. This document describes the basic ideas behind linear prediction, and discusses some of the issues involved in its use.

Linear prediction model speech waveforms are same by estimating the current value from the previous values. The predicted value is a linear combination of previous values. The linear predictor coefficients are determined such that the coefficients minimize the error between the actual and estimated signal. The basic equation of linear prediction is given as follows:
aaa
theory
LPC starts with the assumption that the speech signal is produced by a buzzer at the end of a tube. The glottis (the space between the vocal cords) produces the buzz, which is characterized by its intensity (loudness) and frequency (pitch). The vocal tract (the throat and mouth) forms the tube, which is characterized by its resonances, which are called formants. For more information about speech production, see the Speech Production OLT.
LPC analyzes the speech signal by estimating the formants, removing their effects from the speech signal, and estimating the intensity and frequency of the remaining buzz. The process of removing the formants is called inverse filtering, and the remaining signal is called the residue.
The numbers which describe the formants and the residue can be stored or transmitted somewhere else. LPC synthesizes the speech signal by reversing the process: use the residue to create a source signal, use the formants to create a filter (which represents the tube), and run the source through the filter, resulting in speech.
Because speech signals vary with time, this process is done on short chunks of the speech signal, which are called frames. Usually 30 to 50 frames per second give intelligible speech with good compression.

A. Speech Production

When a person speaks, his or her lungs work like a power supply of the speech production system. The glottis supplies the input with the certain pitch frequency (F0). The vocal tract, which consists of the pharynx and the mouth and nose cavities, works like a musical instrument to produce a sound. In fact, different vocal tract shape would generate a different sound. To form different vocal tract shape, the mouth cavity plays the major role. To produce nasal sounds, nasal cavity is often included in the vocal tract. The nasal cavity is connected in parallel with the mouth cavity. The simplified vocal tract is shown in Fig 3.2.

vocal-tract
The glottal pulse generated by the glottis is used to produce vowels or voiced sounds. And the noise-like signal is used to produce consonants. ..or unvoiced sounds.

B. Linear Prediction Model

An efficient algorithm known as the Levinson-Durbin algorithm is used to estimate the linear prediction coefficients from a given speech waveform.

Assume that the present sample of the speech is predicted by the past M samples of the speech such that

Where the prediction of is is the kth step previous sample, and ak are called the linear prediction coefficients.

The transfer function is given by

Because ε(n), residual error, has less standard deviation and less correlated than speech itself, smaller number of bits is needed to quantize the residual error sequence. Equation can be rewritten as the difference equation of a digital filter whose input is ε (n) and output is s (n) such that

The implementation of the above equation is called the synthesis filter and is shown in Figure 3.5.

If both the linear prediction coefficients and the residual error sequence are available, the speech signal can be reconstructed using the synthesis filter. In practical speech coders, linear prediction coefficients and residual error samples need to be compressed before transmission. Instead of quantizing the residual error, sample by sample, several important parameters such as pitch period, code for a particular excitation, etc are transmitted. At the receiver, the residual error is reconstructed from the parameters.

3.3 CODE EXCITED LINEAR PEDICTION (CELP)

Although the data rate of plain LPC coders is low, the speech reproduction, while generally intelligible, has a metallic quality, and the vocoder artifacts are readily apparent in the unnatural characteristics of the sound. The reason for this is because this algorithm does not attempt to encode the excitation of the source with a high degree of accuracy. The CELP algorithm attempts to resolve this issue while still maintaining a low data rate.

Speech frames in CELP are 30 ms in duration, corresponding to 240 samples per frame using a sampling frequency of 8000 Hz. They are further partitioned into four 7.5 ms sub frames of 60 samples each. The bulk of the speech analysis/synthesis is performed over each sub frame.

The CELP algorithm uses two indexed codebooks and three lookup tables to access excitation sequences, gain parameters, and filter parameters. The two excitation sequences are scaled add summed to form the input excitation to a digital filter created from the LPC filter parameters. The codebooks consist of sequences which are each 60 samples long, corresponding to the length of a sub frame.

CELP is referred to as an analysis by synthcsis technique.
celp-analyzer
Figure 3.6 shows a schematic diagram of the CELP analyzer/coder. The stochastic codebook is fixed containing 512 zero mean Gaussian sequences. The adaptive codebook has 256 sequences formed from the input sequences to the digital filter and updated every two sub frames. A code from the stochastic codebook is scaled and summed with a gain scaled code from the adaptive codebook.

The result is used as the input excitation sequence to an LPC synthesis filter. The output of the filter is compared to the actual speech signal, and the weighted error between the two is compared to the weighted errors produced by using all of the other codewords in the two codebooks. The codebook indices of the two codewords (one each from the stochastic add adaptive codebooks), along with their respective gains, which minimize the error are then coded for transmission along with the synthesis filter (LPC) parameters. Because, the coder passes each of the adaptive and stochastic codewords through the synthesis filter before selecting the optimal codewords.

Chapter 4

CHANNEL CODING

We considered the problem of digital modulation by means of M=2k signal waveforms, where each waveform conveys k bits of information. We observed that some modulation methods provide better performance than others. In particular, we demonstrated that orthogonal signaling waveforms allow us to make the probability of error arbitrarily mail by letting the number of waveforms M → ∞ provided that the SNR per bit γb ≥ 1.6 dB. Thus, we can operate at the capacity of the Additive White Gaussian Noise channel in the limit as the bandwidth expansion factor Be =W/R→∞. This is a heavy price to pay, because Be grows exponentially with the block length k. Such inefficient use of channel bandwidth is highly undesirable.

In this and the following chapter, we consider signal waveforms generated from either binary or no binary sequences. The resulting waveforms are generally characterized by a bandwidth expansion factor that grows only linearly with k. Consequently, coded waveforms offer the potential for greater bandwidth efficiency than orthogonal M ary waveforms. We shall observe that. In general, coded waveforms offer performance advantages not only in power limited applications where RIW<1, but also in bandwidth limited systems where R/W > 1.

We begin by establishing several channel models that will be used to evaluate the benefits of channel coding, and we shall introduce the concept of channel capacity for the various channel models, then, we treat the subject of code design for efficient communications.

4.1 CHANNEL MODEL

In the model of a digital communication system described in chapter 2, we recall that the transmitter building block; consist of the discrete input, discrete output channel encoder followed by the modulator. The function of the discrete channel encoder is to introduce, in a controlled manner, some redundancy in the binary information sequence, which can be used at the receiver to overcome the effects of noise and interference encountered in the transmission of the signal through the channel. The encoding process generally involves taking k information bits at a time and mapping each k bit sequence into a unique n bit sequence, called a code word. The amount of redundancy introduced by the encoding of the data in this manner is measured by the ratio n/k. The reciprocal of this ratio, namely k/n, is called the code rate.

The binary sequence at the output of the channel encoder is fed to the modulator, which serves as the interface to the communication channel. As we have discussed, the modulator may simply map each binary digit into one of two possible waveforms, i.e., a 0 is mapped into s1 (t) and a 1 is mapped into S2 (t). Alternatively, the modulator may transmit q bit blacks at a time by using M = 2q possible waveforms.

At the receiving end of the digital communication system, the demodulator processes the channel crurrupted waveform and reduces each waveform to a scalar or a vector that represents an estimate of the transmitted data symbol (binary or M ary).The detector, which follows the demodulator, may decide on whether the ‘transmitted bit is a 0 or a 1. In such a case, the detector has made a hard decision. If we view the decision process at the detector as a form of quantization, we observe that a hard decision corresponds to binary quantization of the demodulator output. More generally, we may consider a detector that quantizes to Q > 2 levels, i.e. a Q ary detector. If M ary signals are used then Q ≥ M. In the extreme case when no quantization is performed, Q = M. In the case where Q > M, we say that the detector has made a soft decision.

A. Binary Symmetric Channel

Figure 4.1: A composite discrete-input, discrete output channel

Let us consider an additive noise channel and let the modulator and the demodulator/detector be included as parts of the channel. If the modulator employs binary waveforms and the detector makes hard decisions, then the composite channel, shown in Fig. 4.1, has a discrete-time binary input sequence and a discrete-time binary output sequence. Such a composite channel is characterized by the set X = {0, 1} of possible inputs, the set of Y= {0, 1} of possible outputs, and a set of conditional probabilities that relate the possible outputs to the possible inputs. If the channel noise and other disturbances mum statistically independent errors in the transmitted binary sequence with average probability P then,

P(Y = 0 / x = 1) = P(Y = 1 / x = 0) = P

P(Y = 1 / x = 1) = P(Y = 0 / X = 0) = 1- P
Thus, we have reduced the cascade of the binary modulator, the waveform channel, and the binary demodulator and detector into an equivalent discrete-time channel which is represented by the diagram shown in Fig 4.1. This binary-input, binary-output, symmetric channel is simply called a binary symmetric channel (BSC).

B. Discrete Memory Less Channel

The BSC is a special can of a more general discrete-input, discrete-output channel. Suppose that the output form the channel encoder are q ary symbols, i.e., X={x0, x1,…,xq -1) and the output of the decoder consists of q ary symbols, where Q ≥M =2q.

Figure 4.2: Binary symmetric channels

If the channel and the modulation are memory less, then the input-output characteristics of the composite channel, shown in Fig. 4.1, are described by a set of qQ conditional probabilities.

C. Waveform Channels

We may separate the modulator and demodulator from the physical channel, and consider a channel model in which the inputs are waveforms and the outputs are waveforms. Let us assume that such a channel has a given bandwidth W, with ideal frequency response C(f) =1 within the bandwidth W, and the signal at its output is corrupted by additive white Gaussian noise. Suppose that x (t) is a band-limited input to such a channel and y (t) is the corresponding output, then,

y(t) = x(t) + n(t)

Where n(t) represents a sample function of the additive noise process.

4.2 CONVOLUTIONAL CODES

For (n,1) convolution codes, each bit of the information sequence into the encoder results in an output of n bits. However, unlike block codes, the relationship between information bits and output bits is not a simple one-to-one mapping. In fact, each input information bit is ‘convolved’ with K-1 other information bits to form the output n bit sequence. The value K is known as the constraint length of the code and is directly related to its encoding and decoding complexity as described below in a brief explanation of the encoding process.

For each time step, an incoming bit is stored in a K stage shift register, and bits at predetermined locations in the register are passed to n modulo 2 adders to yield the n output bits. Each input bit enters the first stage of the register, and the K bits already in the register are each shifted over one stage with the last bit being discarded from the last stage.

The n output bits produced by the entry of each input bit have a dependency on the preceding K-1 bits. Similarly, since it is involved in the encoding of K-1 input bits in addition to itself, each input bit is encoded in nK output bits. It is in this relationship that convolutional coding derives its power. For larger values of K, the dependencies among the bits increased the ability to correct more errors rises correspondingly. But the complexity of the encoder and especially of the decoder also becomes greater.

convolutional code encoder
Shown in Figure 4.3 is the schematic for a (2,1) encoder with constraint length K= 3 which will serve as the model for the remainder of the development of convolutional coding. In the coder shown, the n = 2 output bits are formed by modulo 2 addition of the bits in stages one and three and the addition of bits in stages one, two, and three of the shift register.

Chapter 5

MODULATION

In this chapter, we describe the basic Modulation Technique and emphasis on QPSK Modulation which is use in this thesis. We are trying to show how QPSK Modulation is used in digital communication system. In digital transmission systems, the data sequence from the channel encoder is partitioned into L bit words, and each word is mapped to one of M corresponding waveforms according to some predetermined rule, where M = 2L. We shall see later, in a QPSK modulation system, the incoming sequence is separated into words of L = 2 bits each and mapped to M = 22 = 4 different waveforms. During transmission, the channel causes attenuation and introduces noise to the signal. The net result is the formation of a version of the original signal which may not be detected correctly by the receiver. If the errors are too numerous, the channel decoder may not be able to resolve the information correctly. Baseband modulation using the simple binary symmetric channel model is briefly discussed, and the details of QPSK modulation are then presented.

We organize this chapter as follows. First, we review some basic from Modulation Technique. We present basic modulation of Amplitude Shift-keying (ASK), Frequency Shift-keying(FSK),Phase Shift-keying(PSK), Binary Phase Shift-keying (BPSK) and Quadrature Phase Shift-keying(QPSK). We then talk about Quadrature Phase Shift-keying(QPSK) in detail and try to show the use of QPSK in digital communication system.

5.1 AMPLITUDE SHIFT KEYING (ASK)

In many situations, for example in radio frequency transmission, data cannot be transmitted directly, but must be used to modulate a higher frequency sinewave carrier. The simplest way of modulating a carrier with a data stream is to change the amplitude of the carrier every time the data changes. This technique is known as amplitude shift -keying.

The simplest form of amplitude shift-keying is on- off keying, where the transmitter outputs the sinewave carrier whenever the data bit is a ‘1’, and totally suppresses the carrier when the data bit is ‘0’. In other words, the carrier is turned ‘on’ for a ‘1’, and ‘off ‘ for a ‘0’.This form of amplitude shift-keying is illustrated in figure below:

Figure 5.1: an ASK signal (below) and the message (above)

In order to generate an amplitude shift-keyed (ASK) wave form at the Transmitter a balanced modulator circuit is used (also known as a linear multiplier). This device simply multiplies together the signals at its two inputs, the output voltage at any instant in time being the product of the two input voltages. One of the inputs is a.c. coupled; this is known as the carrier input. The other is d.c. coupled and is known as the modulation (or signal) input.

In order to generate the ASK waveform, all that is necessary is to connect the sine wave carrier to the carrier input, and the digital data stream to the modulation input, as shown in figure below:

Figure 5.2: ASK generation method

The data stream applied to the modulator’s modulation input is unipolar, i.e. its ‘0’ and ‘1’ levels are 0 volts and +5volts respectively. Consequently.

(1) When the current data bit is a ‘1’ , the carrier is multiplied by a constant, positive voltage, causing the carrier to appear, unchanged in phase, at the modulator’s output.

(2) When the current data bit is a ‘0’, the carrier is multiplied by 0 volts, giving 0 volt as at the modulators output.

At the Receiver, the circuitry required to demodulate the amplitude shift- keyed wave form is minimal.The filter’s output appears as a very rounded version of the original data stream, and is still unsuitable for use by the “Receiver’s digital circuits. To overcome this, the filter’s output wave form is squared up by a voltage comparator.

5.2 Frequency Shift-keying

In frequency shift -keying, the signal at the Transmitter’s output is switched from one frequency to another every time there is a change in the level of the modulating data stream For example, if the higher frequency is used to represent a data ‘1’ and the lower ferquency a data ‘0’, the reasulting Frequency shift keyed (FSK) waveform might appear as shown in Figure below:

Figure 5.3 An ASK waveform

The generations of a FSK waveform at the Transmitter can be acheived by generating two ASK waveforms and adding them together with a summing amplifier.

At the Receiver, the frequency shift-keyed signal is decoded by means of a phase-locked loop (PLL) detector. The detector follows changes in frequency in the FSK signal, and generates an output voltage proportional to the signal ferquency.

The phase-locked loop’s output also contains components at the two carrier frequencies; a low-pass fillter is used to filter these components out.

The filter’s output appears as a very rounded version of the original data stream, and is still unsuitable for use by the Receiver’s digital circuits. To overcome this, the filter’s output waveform is squared up by a voltage comparator. Figure below shows the functional blocks required in order to demodulate the FSK waveform at the Receiver.

5.3 Phase Shift keying (PSK)

In phase shift keying the phase of the carrier sinewave at the transmitter’s output is switched between 0 º and 180 º, in sympathy with the data to be transmitted as shown in figure below:

Figure 5.3: phase shift keying

The functional biocks required in order to generate the PSK signal are similar to those required to generate an ASK signal. Again a balanced modulator is used, with a sinewave carrier applied to its carrier input. In contscast to ASK generation, however, the digital signal applied to the madulation input for PSK generation is bipolar, rather than unipolar, that is it has equal positive and negative voltage levels.

When the modulation input is positive, the modulator multiplies the carier input by this constant level. so that the modulator’s output signal is a sinewave which is in phase with the carrier input.

When the modulation input is negative, the modulator multiplies the carrier input by this constant level, so that the modulatior’s autput signal is a sinewave which is 180 º out of phase with the carier input.

At the Receiver, the frequency shift-keyed signal is decoded by means of a squaring loop detector. This PSK Demodulator is shown in figure below:

5.4 BINARY PHASE-SHIFT KEYING (BPSK)

In binary phase shift keying (BPSK), the transmitted signal is a sinusoid of fixed amplitude it has one fixed phase when the data is at one level and when the data is at the other level the phase is different by 180 º . If the sinusoid is of Amplitude A it has a power :

Ps = 1/2 A2
A = Root over (2 Ps)

BPSK(t) = Root over (2 Ps) Cos (ω0t)
BPSK(t) = Root over (2 Ps) Cos (ω0t+π )
= – Root over (2 Ps) Cos (ω0t)

In BPSK the data b(+) is a stream of binary digits with voltage levels which, we take to be at +1V and – 1 V. When b(+) =1V we say it is at logic 1 and when b(+)= -1V we say it is logic 0. Hence, BPSK(t) can be written as:

BPSK(t) = b(t) Root over (2 Ps) Cos (w0t)

In practice a BPSK signal is generated by applying the waveform Coswo as a carrier to a balanced modulator and applying the baseband signal b(+) as the modulating signal. In this sense BPSK can be thought of as an AM signal similar as PSK signal.

5.5 Quadrature Phase Shift Keying (QPSK)

In this section the topics of QPSK modulation of digital signals including their transmission, demodulation, and detection, are developed. The material in this section and the related coding of this system are both based on transmission using an AWGN channel model which is covered at the end of this section. Some of the techniques discussed below are specifically designed for robustness under these conditions.

Because this is a digital implementation of a digital system, it is important to note that the only places where analog quantities occur are after the DAC, prior to the actual transmission of the signal, and before the ADC at the receiver. All signal values between the source encoder input and modulator output are purely digital. This also holds for all quantities between the demodulator and the source decoder.

A. Background

QPSK modulation is a specific example of the more general M ary PSK. For M ary PSK, M different binary words of length L = log2 M bits are assigned to M different waveforms. The waveforms we at the same frequency but separated by multiples of φ = 2π/M in phase from each other and can be represented as follows:

, =

with i = 1, 2, … M. The carrier frequency and sampling frequency are denoted by fc and fs respectively.

Since an M ary PSK system uses L bits to generate a waveform for transmission, its symbol or baud rate is 1IL times its bit rate. For QPSK, there we M = 4 waveforms separated by multiples of ( = ) radians and assigned to four binary words of length L = 2 bits. Because QPSK requires two incoming bits before it can generate a waveform, its symbol or baud rate, D, is one half of its bit rate, R.

B. Transmitter

Figure 5.2 illustrates the method of QPSK generation. The first step in the formation of a QPSK signal is the separation of the incoming binary data sequence, b, into an in phase bit stream, b1, and a quadratic phase bits ream, bQ, as follows. If the incoming data is given by b = bo, b1, b2, b3, b4…. where bi are the individual bits in the sequence, then, bI = bo, b2, b4 ……(even bits of b) and bQ= b1, b3, b5 …… (odd bits). The digital QPSK signal is created by summing a cosine function modulated with the bI, stream and a sine function modulated by the bQ stream. Both sinusoids oscillate at the same digital frequency, ω0=2π fc / fs radians. The QPSK signal is subsequently filtered by a band pass filter, which will be described later, and sent to a DAC before it is finally transmitted by a power amplifier.

Figure 5.4 QPSK Modulator
B.1 Signal Constellation

It is often helpful to represent the modulation technique with its signal space representation in the I Q plane as shown in Figure 5.3. The two axes, I and Q, represent the two orthogonal sinusoidal components, cosine and sine, respectively, which are added together to form the QPSK signal as shown in Figure 5.2. The four points in the plane represent the four possible QPSK waveforms and me separated by multiples of n/2 radians from each other. By each signal point is located the input bit pan which produces the respective waveform. The actual I and Q coordinates of each bit pair are the contributions of the respective sinusoid to the waveform. For example, the input bits (0, 1) in the second quadrant correspond to the (I,Q) coordinates, ( 1,1). This yields the output waveform I + Q = cos (ω0n) + sin (ω0n). Because all of the waveforms of a QPSK have the same amplitude, all four points are equidistant from the origin. Although the two basis sinusoids shown in Figure 5.2 are given by cos (ω0n) and sin (ω0n), the sinusoids can be my two functions that are orthogonal.

Figure 5.3 Signal Constellation of QPSK

B.2 Filtering

The QPSK signal created by the addition of the two sinusoids has significant energy in frequencies above and below the carrier frequency. This is due to the frequency contributions incurred during transitions between symbols which are either 90 degrees or 180 degrees out of phase with each other. It is common to limit the out of band power by using a digital band pass filter (BPF) centered at ωo. The filter has a flat pass band and a bandwidth which is 1.2 to 2 times the symbol rate.

C. Receiver

The receiver’s function consists of two steps: demodulation and detection. Demodulation entails separating the received signal into its constituent components. For a QPSK signal, these are the cosine and sine waveforms carrying the bit information. Detection is the process of determining the sequence of ones and zeros those sinusoids represent.

C.1 Demodulator

The demodulation procedure is illustrated below in Figure 5.4. The first step is to multiply the incoming signal by locally generated sinusoids. Since the incommoding signal is a sum of sinusoids, and the receiver is a linear system, the processing of the signal can be treated individually for both components and summed upon completion.

Figure 5.4: QPSK Demodulator and Detector

Assuming the received signal is of the form

r(n) = AI cos(ω0 n) + AQ sin (ω0 n)

where AI and AQ are scaled versions of the bI and bQ bitstreams used to modulate the signal at the transmitter. The contributions through the upper and lower arms of the demodulator due to the cos(ω0 n) input alone are

rci = AI cos(ω0 n) cos (ω0 n+ ө)

rcQ = AI cos(ω0 n) sin (ω0 n+ ө)

where ө is the phase difference between the incoming signal and locally generated sinuso¬ids. These equations can be expanded using trigonometric identities to yield.

C.2 Detection

After the signal r(n) has been demodulated into the bitstreams dj(n) and dQ(n), the corresponding bit information must be recovered. The commonly used technique is to use a matched filter at the output of each LPF as shown in Figure 5.4. The matched filter is an optimum receiver under AWGN channel conditions and is designed to produce a maximum output when the input signal is a min or image of the impulse response of the filter. The outputs of the two matched filters are the detected bitstreams bdj and bdO, and they are recombined to form the received data bitstream. The development of the matched filter and its statistical properties as an optimum receiver under AWGN conditions can be found in various texts.

5.6 AWGN Channel

The previously introduced BSC channel modeled all of the channel effects with one parameter, namely the BER; however, this model is not very useful when attempting to more accurately model a communication system’s behavior. The biggest drawback is the lack of emphasis given to the noise which significantly corrupts all systems.

The most commonly used channel model to deal with this noise is the additive white Gaussian noise (AWGN) channel model. The time results because the noise is simply added to the signal while the term ‘white’ is used because the frequency content is equal across the entire spectrum. In reality, this type of noise does not exist and is confined to a finite spectrum, but it is sufficiently useful for systems whose bandwidths are small when compared to the noise power spectrum.

Chapter 6

CHANNEL EQUALIZATION

Equalization is partitioned into two broad categories. The first category, maximum likelihood sequence estimation (MLSE), entails making measurements of impulse response and then providing a means for adjusting the receiver to the transmission environment. The goal of such adjustment is to enable the detector to make good estimates from the demodulated distorted pulse sequence. With an MLSE receiver, the distorted samples are not reshaped or directly compensated in any way; instead, the mitigating techniques for MLSE receiver is to adjust itself in such a way that it can better deal with the distorted samples such as Viterbi equalization.
The second category, equalization with filters, uses filters to compensate the distorted pulses. In this second category, the detector is presented with a sequence of demodulated samples that the equalizer has modified or cleaned up from the effects of ISI. The filters can be distorted as to whether they are linear devices that contain only feed forward elements (transversal equalizer), or whether they are nonlinear devices that contain both feed for ward and feedback elements (decision feedback equalizer) the can be grouped according to the automatic nature of their operation, which may either be preset or adaptive.
They are also grouped according to the filter’s resolution or update rate.
Symbol spaced
Pre detection samples provided only on symbol boundaries, that is, one sample per symbol. If so, the condition is known.
Fractionally spaced
Multiple samples provided for each symbol. If so, this condition is known.

6.1 ADAPTIVE EQUALIZATION
An adaptive equalizer is an equalization filter that automatically adapts to time-varying properties of the communication channel. It is frequently used with coherent modulations such as phase shift keying, mitigating the effects of multipath propagation and Doppler spreading. Many adaptation strategies exist. A well-known example is the decision feedback equalizer, a filter that uses feedback of detected symbols in addition to conventional equalization of future symbols. Some systems use predefined training sequences to provide reference points for the adaptation process.
Adaptive equalization is capable of tracking a slow time varying channel response. It can be implemented to perform tap weight adjustments periodically or continually. Periodic adjustments are accomplished by periodically transmitting a preamble or short training sequence of digital data that is known in advance by the receiver. The receiver also detects the preamble to detect start of transmission, to set the automatic gain control level, and to align internal clocks and local oscillator with the received signal. Continual adjustments are accomplished by replacing the known training sequence with a sequence of data symbol estimated from the equalizer output and treated as known data. When performed continually and automatically in this way, the adaptive procedure is referred to as decision directed. Decision directed only addresses how filter tap weights are adjusted-that is with the help of signal from the detector. DFE, however, refers to the fact that there exists an additional filter that operates on the detector output and recursively feed back a signal to detector input. Thus with DFE there are two filters, a feed forward filter and a feed back filter that processes the data and help mitigate the ISI.
Adaptive equalizer particularly decision directed adaptive equalizer, successfully cancels ISI when the initial probability of error exceeds one percent. If probability of error exceeds one percent, the decision directed equalizer might not converge. A common solution to this problem is to initialize the equalizer with an alternate process, such as a preamble to provide good channel error performance, and then switch to the decision directed mode. To avoid the overhead represented by a preamble many systems designed to operate in a continuous broadcast mode use blind equalization algorithms to form initial channel estimates. These algorithms adjust filter coefficients in response to sample statistics rather than in response to sample decisions.
Automatic equalizer use iterative techniques to estimate the optimum coefficients. The simultaneous equations do not include the effects of channel noise. To obtain a stable solution to the filter weights, it is necessary that the data are average to obtain, stable signal statistics or the noisy solution obtained from the noisy data must be averaged considerations of algorithm complexity and numerical stability most often lead to algorithms that average noisy solutions. The most robust of this class of algorithm is the least mean square algorithm.
6.2 LMS ALGORITHM FOR OEFICIENT ADJUSTMENT

Suppose we have an FIR filter with adjustable coefficient {h(k),0<k<N-1}. Let x(n) denote the input sequence to the filter, and let the corresponding output be {y(n)}, where
y(n) = n=0,….M

Suppose we also have a desired sequence d(n) with which we can compare the FIR filter output. Then we can form the error sequence e(n) by taking the difference between d(n) and y(n). That is,
e(n)=d(n)-y(n), n=0,….M
The coefficient of FIR filter will be selected to minimize the sum of squared errors.
Thus we have

+
where, by definition,
rdx(k)= 0 ≤ k ≤ N-1
rxx(k)= 0 ≤ k ≤ N-1
We call rdx(k) the cross correlation between the desired output sequence d(n) and the input sequence x(n), and rxx(k) is the auto correlation sequence of x(n).
The sum of squared errors ε is a quadratic function of the FIR filter coefficient. Consequently, the minimization of ε with respect to filter coefficient h(k) result in a set of linear equations. By differentiating ε with respect to each of the filter coefficients, we obtain,

∂ε /∂h(m)=0, 0 ≤ m ≤ N-1
and, hence
rxx(k-m)=rdx(m), 0 ≤ k ≤ N-1
This is the set of linear equations that yield the optimum filter coefficients.
To solve the set of linear equations directly, we must first compare the autocorrelation sequence rxx(k) of the input signal and cross correlation sequence rdx(k) between the desired sequence d(n) and input sequence x(n).
The LMS provides an alternative computational method for determining the optimum filter coefficients h(k) without explicitly computing the correlation sequences rxx(k) and rdx(k). The algorithm is basically a recursive gradient (steepest-descent) method that finds the minimum of ε and thus yields the optimum filter coefficients.
We begin with the arbitrary choice for initial values of h(k), say h0(k). For example we may begin with h0(k)=0, 0 ≤ k ≤ N-1,then after each new input sample x(n) enters the adaptive FIR filter, we compute the corresponding output, say y(n), from the error signal e(n)=d(n)-y(n), and update the filter coefficients according to the equation
hn(k)=hn-1(k)+ Δ.e(n).x(n-k), 0 ≤ k ≤ N-1, n=0,1,…..
where Δ is called the step size parameter, x(n-k) is the sample of the input signal located at the kth tap of the filter at time n, and e(n).x(n-k) is an approximation (estimate) of the negative of the gradient for the kth filter coefficient. This is the LMS recursive algorithm for adjusting the filter coefficients adaptively so as to minimize the sum of squared errors ε.
The step size parameter Δ controls the rate of convergence of the algorithm to the optimum solution. A large value of Δ leads to a large step size adjustments and thus to rapid convergence, while a small value of Δ leads to slower convergence. However if Δ is made too large the algorithm becomes unstable. To ensure stability, Δ must be chosen to be in the range
0< Δ < 1/10NPx
Where N is length of adaptive FIR filter and Px is the power in the input signal, which can be approximated by
Px ≈ 1/(1+M)

Figure 6.1: LMS ALGORITHM FOR OEFICIENT ADJUSTMENT

6.3 ADAPTIVE FILTER FOR ESTIMATING AND SUPPRESSING AWGN INTERFERENCE

Let us assume that we have a signal sequence x(n) that consists of a desired signal sequence, say w(n), computed by an AWGN interference sequence s(n). The two sequences are uncorrelated.

The characteristics of interference allow us to estimate s(n) from past samples of the sequence x(n)=s(n)+w(n) and to subtract the estimate from x(n).

The general configuration of the interference suppression system is shown in the entire block diagram of the system. The signal x(n) is delayed by D samples, where delay is chosen sufficiently large so that the signal components w(n) and w(n-D), which are contained in x(n) and x(n-D) respectively, are uncorrelated. The out put of the adaptive FIR filter is the estimate

s(n) =

The error signal that is used in optimizing the FIR filter coefficients is e(n)=x(n)-s(n). The minimization of the sum of squared errors again leads to asset of linear equations for determining the optimum coefficients. Due to the delay D, the LMS algorithm for adjusting the coefficients recursively becomes,
hn(k)=hn-1(k)+ Δ.e(n).x(n-k-D), k=0,1,…..N-1

Chapter 7

DEMODULAITON

Function of receiver consists of two parts:

A. Demodulation

B. Detection

Demodulation is the act of extracting the original information-bearing signal from a modulated carrier wave. A demodulator is an electronic circuit used to recover the information content from the modulated carrier wave. Coherent Demodulation is accomplished by demodulating using a local oscillator (LO) which is at the same frequency and in phase with the original carrier. The simplest form of non-coherent demodulation is envelope detection. Envelope detection is a technique that does not require a coherent carrier reference and can be used if sufficient carrier power is transmitted.

Although the structure of a non-coherent receiver is simpler than is a coherent receiver, it is generally thought that the performance of coherent is superior to non-coherent in a typical additive white Gaussian noise environment. Demodulation entails separating the received signal into its constituent components. For a QPSK signal, these are cosine and sine waveforms carrying the bit information. Detection is the process of determining the sequence of ones and zeros those sinusoids represent.

7.1 DEMODULATION

The first step is to multiply the incoming signal by locally generated sinusoids. Since the incoming signal is a sum of sinusoids, and the receiver is a linear system, the processing of the signal can be treated individually for both components summed upon completion. Assuming the received signal is of the form

r(n)=Ai cos(ω0n)+Aq sin(ω0n)

where Ai and Aq are scaled versions of the bi and bq bit stream used to modulate the signal at the transmitter. Due to cos(ω0n) input alone,

rci(n)= Ai cos(ω0n) cos(ω0n+Ө)

and

rcq (n)= Ai cos(ω0n) sin(ω0n+Ө)

where Ө is the phase difference between incoming signal and locally generated sinusoids. Similarly for sin(ω0n) portion of the input r(n),

rsi(n)= Ai sin(ω0n) cos(ω0n+Ө)……….7.1

and

rsq(n)= Ai sin(ω0n) sin(ω0n+Ө)………..7.2

7.2 SYNCHRONIZATION

For the received data to be interpreted and detected correctly there needs to be coordination between the receiver and transmitter. Since they are not physically connected, the receiver has no means of knowing the state of the transmitter. This state includes both the phase argument of the modulator and the bit timing of the transmitted data sequence. The receiver must therefore extract the desired information from the received digital signal to achieve synchronization. A common means of accomplishing synchronization is with a PLL. A phase-locked loop or phase lock loop (PLL) is a control system that generates a signal that has a fixed relation to the phase of a “reference” signal. A phase-locked loop circuit responds to both the frequency and the phase of the input signals, automatically raising or lowering the frequency of a controlled oscillator until it is matched to the reference in both frequency and phase. PLL compares the frequencies of two signals and produces an error signal which is proportional to the difference between the input frequencies. The error signal is then low-pass filtered and used to drive a voltage-controlled oscillator (VCO) which creates an output frequency. The output frequency is fed through a frequency divider back to the input of the system, producing a negative feedback loop. If the output frequency drifts, the error signal will increase, driving the frequency in the opposite direction so as to reduce the error. Thus the output is locked to the frequency at the other input. This input is called the reference and is often derived from a crystal oscillator, which is very stable in frequency. At first the received signal is raised to 4th power. Then it is passed through a 4th order band pass filter and frequency divider. Thus the two sinusoid outputs used to demodulate the received signal are produced.

7.3 DETECTION

The signals [equation (7.1) and (7.2)] are passed through corresponding envelop detector and threshold comparator to obtain I data and Q data. An envelope detector is an electronic circuit that takes a high-frequency signal as input, and provides an output which is the “envelope” of the original signal. The capacitor in the circuit stores up charge on the rising edge, and releases it slowly through the resistor when the signal falls. The diode in series ensures current does not flow backward to the input to the circuit. Then threshold comparators compare the signals with their values and generate the I data and Q data. These are recombined by switching device to form received bit stream.

detection

Figure 7.1: DETECTION

7.4 AWGN Channel

During transmission, the signal undergoes various degrading and distortion effects as it passes through the medium from transmitter to receiver. This medium is commonly referred to as the channel. Channel effects include but are not limited to noise, interference, linear and non linear distortion and attenuation. These effects are contributed by a wide verity of sources including solar radiation, weather and signal from adjacent channels. But many of the prominent effects originate from the components in the receiver. While many of the effects can be greatly reduced by good system design, careful choice of filter parameters and coordination of frequency parameter usage with other users, noise and attenuation generally can not be avoided and are the largest contributors to signal distortion.

The most commonly used channel model to deal with noise is the additive white Gaussian noise (AWGN) channel model. The name results because the noise is simply added to the signal while the term white is used because the frequency content is equal across the entire spectrum. In reality this type of noise does not exists and is confined to a finite spectrum, but it is sufficiently useful for systems whose bandwidth are small compared to the noise power spectrum. When modeling a system across an AWGN channel, the noise must first be filtered to the channel prior to addition.

Chapter 8

RESULTS

8.1 SIMULATION

The section describes the performance of QPSK Modulation for speech.The simulation was done using MATLAB 7 platform.

All codes for this chapter are contained in Appendix A. An adaptive filter is used in these routines. All of the repeatedly used values such as cosine and sine are retrieved from look up tables to reduce computation load.

8.2 TRANSMITTER

A speech signal is transmitted through the entire system. In each case speech signals are obtained from the internet. These are short segments of speech data of 6-7 seconds. From the speech signal 30874 samples are taken.

These samples are then quantized. Here 4 bit PCM is used (as 8 bit or higher PCM takes longer time during the simulation) to obtain a total of 123496 bits from 30874 samples.

The bits are divided into even bits and odd bits using flip flop. Here for simplicity and for the purpose of better understanding only 8 bits are shown on the figure instead of 123496 bits. Consider that the bit sequence is 11000110.

The even bits (1010) are modulated using a carrier signal (sine wave) and odd bits (1001) are modulated using the same carrier signal with 90 degree phase shift (cosine wave). The modulation process is explained explicitly in the previous sections. In the case of odd data cosine wave represents 1 while cosine wave with 180 degree phase shift represents 0. On the other hand in the case of even data sine wave represents 1 and sine wave with 180 degree phase shift represents 0. The odd data and even data are modulated separately in this way and then added using a linear adder to obtain QPSK modulated signal. This signal is passed through a band pass filter and transmitted through the channel.

8.3 Channel and receiver

In this system AWGN channel is considered. As the signal passes through the channel it is corrupted by AWGN noise. AWGN command in MATLAB is used to generate this noise. Here SNR is taken sufficiently large to avoid possibility of bit errors. Bit error rate and the performance of the system depend highly on the SNR which is discussed later in this chapter. To remove this AWGN interference sequence from the received signal the signal is passed through an adaptive filter. The adaptive filter uses LMS algorithm which is explained explicitly in the previous sections. Then the desired signal is obtained.

This desired signal is then passed through the demodulation process. At first it is passed through a PLL to obtain necessary carrier signal. Here for simplicity the angle generated by PLL is considered zero. At one side this desired signal is demodulated with sine wave to obtain even data while on the other side it is demodulated by cosine wave to obtain odd data.

Then these signals are passed through corresponding envelop detector and threshold comparator to obtain odd data and even data. When data is greater than .75 then it detected as 1 on the other hand when data is less than .75 then it is detected as 0. After that a switching device is used to combine odd data and even data.

Then this bit stream is passed through the decoder and the received speech signal is obtained. This received signal can be heard using soundsc command

Here theoretical Eb/N0 vs. BER curve for QPSK is shown

CHAPTER-9

CONCLUSION

In this project the details of a digital communication system implementation using QPSK modulation and adaptive equalization have been discussed. Pulse-code modulation (PCM) is a digital representation of an analog signal where the magnitude of the signal is sampled regularly at uniform intervals, then quantized to a series of symbols in a numeric (usually binary) code. PCM can facilitate accurate reception even with severe noise or interference. An adaptive equalizer is an equalization filter that automatically adapts to time-varying properties of the communication channel. It is frequently used with coherent modulations. It is useful for estimating and suppressing AWGN interference. Lastly, QPSK is an efficient modulation scheme currently used by modem satellite communication links.
We studied QPSK modulation technique through out the project. Instead of using other modulation techniques such MSK, 8-QPSK, 16-QPSK etc we used 4-QPSK in this project. QPSK is a quaternary modulation method, while MSK is a binary modulation method. In QPSK, the I and Q components may change simultaneously, allowing transitions through the origin. In a hypothetical system with infinite bandwidth, these transitions occur instantaneously; however, in a practical band-limited system (in particular, a system using a Nyquist filter) these transitions take a finite amount of time. This results in a signal with a non-constant envelope. MSK performed in such a way that the transitions occur around the unit circle in the complex plane, resulting in a true constant-envelope signal. Using 8-QPSK and 16-QPSK techniques higher data rate and higher spectral efficiency can be achieved but BER also increases. The performance of MSK, 8-QPSK, 16-QPSK techniques is better but implementation of these techniques is complex. 4-QPSK is simpler and easy to implement. Its spectral efficiency is not higher than that of 8-QPSK, 16-QPSK but it provides lower BER. In this project we performed the simulation of 4-QPSK modulation technique using MATLAB platform accurately and without any error. The system is flexible enough in accommodating any speech signal or analog signal. Digital communication systems can be implemented using QPSK modulation.

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