2012

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A miniaturized interdigital hairpin microstrip bandpass filter design
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Islam, Nafiul; Islam, Istiaque; Haque, Md. Merazul
Modern communication technology is advancing every day. It is becoming more efficient and miniaturized. The efficiency of the communication technology depends upon the performance of the filter used in the system. That’s why extensive research is going on to improve the filter performance as well as to reduce its size. In this thesis we have proposed a four-pole elliptic function band-pass filter designed using compact miniaturized microstrip interdigital hairpin resonator. Miniaturization hairpin resonator is realized by using an interdigital structure having parallel coupled lines. Many works are going on in the field of filter designing. The most recent works has been studied in this thesis to obtain the most suitable design for specific application. We have used the full-wave simulator IE3D to design the interdigital hairpin resonator. We choose RO4003C substrate for our design as it has many advantages in high frequency applications. Finally a filter with chip area of 28.2 * 20.2 mm2 and center frequency at 2.4GHz with a 3db bandwidth of 220 MHz has been proposed. Its upper cutoff and lower cutoff frequencies are respectively 2.53 GHz and 2.31 GHz.
A Unified Approach to Improve the Computation Time and Image Quality of Ultrasound Strain Imaging
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Arfin, Rishad; Ahmed, Rifat; Hossan, Monir
Medical science relies on technology now more than ever. For both diagnosis and treatment blessing of technology is exploited. Diagnosis of disease using technology comes in various forms. Imaging is a particularly attractive diagnosis methodology. Among the existing diagnostic imaging techniques ultrasound has gained much popularity over the years. Apart from the regular ultrasound imaging techniques ultrasound has some special use. Elastography is such an application of ultrasound. It is actually the imaging of the stiffness of the tissue. Elastography is particularly efficient in diagnosing early cancer particularly breast and prostate cancer. For example, breast cancer is diagnosed by invasive biopsy. But elastography can reduce the rate of biopsy since a large fraction of the tumors of breast are found to be benign. Unlike biopsy elastography provides instant result. It relieves the patient from psychological stress to wait for the result. But elastography is much of a qualitative technique. It can be unreliable at some cases. That’s why extensive research is being performed to improve its quality. In our thesis we have worked on two different aspects of the research. We have presented a software tool that can be used for improving the computation time in elastography. Also, we have proposed a concept of using smooth window functions to improve the image quality and presented some experimental results.
Accelerometer based gesture recognition system
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Mahmud, Jisan; Abrar, Murad Mahbub; Toha, Zakaria Rabbi
Comparison among Different Beam Forming Algorithms used in Smart Antenna System for 3G+ Mobile Communications
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Islam, Md. Rezwanul; Wahiduzzaman, Md.; Tanmoy, M. M. Reazul Haque
Smart antenna manipulates the impinging signals on various antenna elements through array processing so that the main lobe is formed towards the desired direction and nulls are placed towards the interference or unwanted directions. Direction of Arrival (DOA) estimation is an important part of direction of arrival based beam forming. The direction of arrival algorithm computes the angle of arrival of all impinging signals. A systemic study of smart antenna system and comparison of the performance of the Bartlett and MUltiple SIgnal Classification(MUSIC) DOA algorithms along with different non blind beam forming algorithms through simulation have been extensively analyzed in this thesis work. Our comparative analysis shows that MUSIC algorithm is highly accurate and stable and provides high angular resolutions compared to Bartlett algorithm. So MUSIC algorithm can be widely used in mobile communication to estimate the DOA of arriving signals. Among LMS, SMI, RLS beam forming algorithms RLS algorithm is the fastest to converge the weights through least computational complexity.
Comparison among different migration paths for cellular deployment in Bangladesh in collaboration with grameenphone
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-10-15) Ahmed, Tanjir; Mosleh, Md. Mukib; Ibrahim, Touheed
The thesis work is a collaboration between Islamic University of Technology and the leading cellular operator of Bangladesh, Grameenphone Ltd. (Telenor) and aims to provide a thorough technological analysis and business case comparison for different migration paths to the next generation technology for the operator. There has been a tremendous growth in service quality and competition among the cellular operators and a continuous demand for network up gradation to a better and efficient cellular technology. Worldwide 3G networks roll out began since 2000 to cater the ever increasing data demand for mobile broadband solution. But unfortunately in Bangladesh, due to regulatory issues, 3G technology couldn’t have been implemented till now. After so many years, The Bangladesh Telecom Regulatory Commission (BTRC) has finished all the required ground works and is expected to arrange a spectrum frequency auction in Q1 of 2013 where in total 5 concessions will be allocated in 2.1 Ghz band, 10 MHz each. Each concession will be a technology neutral one. All the cellular operators of the country are expected to bid on that auction including Grameenphone. Technology neutrality allows the operator to choose and deploy the technology best suited for their business. Till now (October 2012), the next generation technology LTE has been successfully rolled out in 105 networks. So, whether to deploy 3G or go for the next generation technology LTE bypassing 3G/UMTS remains a question any operator, in this case Grameenphone. This thesis tries to answer this question in accordance with Bangladesh’s cellular market perspective taking into considerations the technological aspects as well as a cost revenue analysis done by data provided by Grameenphone Ltd. for both migration paths- 3G (UMTS/HSPA) and LTE.
Design and implementation of an aerial surveillance unit using wireless communication scheme
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-10-15) Islam, Riasat Siam; Hussain, Nafis; Ibrahim, Ismail Bin
In recent times, a wide variety of applications for Aerial Surveillance are being introduced. This project has been aimed to design and implement an Aerial Surveillance Unit that will be used for further research on applications of Aerial Surveillance to traffic management, crime management, pollution control, protection and security. The preliminary prototype will consist of a camera device that will provide live video feed at the remote end and the complete system will be teleoperated. The main control system consists of ATmega2560, for the surveillance system we have used a low power serial camera, the secured communication system consists of a Wi-Fi router connected to Arduino Ethernet Shield, the flight mechanism is accomplished using a high rpm bldc motor and servo motors has been used to control lift, yaw and landing. The surveillance mechanism had worked successfully receiving video at 640x 480 and 320x 240 resolutions. Since, it is a preliminary device there is definite scope for further development to design an Aerial Surveillance Unit for the desired purpose
Design and implementation of digital controllers for buck converter using linear and nonlinear control methods
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Ali, Majid; Khan, Safiullah; Waleed, Muhamad
DC-DC power converters play an important role in powering telecom and computing systems. With the speed improvement and cost reduction of digital control, digital controller is becoming a trend for DC-DC converters in addition to existed digital monitoring and management technology. In this thesis, digital control is investigated for DC-DC converters applications. To deeply understand the whole control systems, DC-DC converter models are investigated based on averaged state-space modeling. Considering Buck DC-DC converter, the thesis takes it as an example for digital control modeling and implementation. In Chapter 3, unified steady-state DC models and small-signal models are developed for DC-DC buck converters. Based on the models, digital controller design is implemented. In Chapter 4, digital modeling platforms are established based on Matlab, Digital PID design and corresponding simulation results are provided. Also some critical issues and practical requirements are discussed. In Chapter 6, a DSP-based digital controller is implemented with the TI‘s DSP chip TMS320F2812. Related implementation methods and technologies are discussed.
Design and simulation of a 2.4 ghz microstrip patch antenna
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Sifat, M.I.K.; Musarrat, Md. Nahin; Rashel, Iftakhar Hossain
In this thesis, an optimization method based on IE3D is used to design an Inset Feed Linearly Polarized Rectangular Microstrip Patch Antenna. The aim of the thesis is to design an inset fed rectangular Microstrip Antenna and study the effect of antenna dimensions length (L) , width (W) and substrate parameters relative dielectric constant (εr) , substrate thickness on Radiation parameters of band width. low dielectric constant substrates are generally preferred for maximum radiation. The conducting patch can take any shape but rectangular and circular configurations are the most commonly used configuration. Other configurations are complex to analyze and require heavy numerical computations. The length of the antenna is nearly half wavelength in the dielectric; it is a very critical parameter, which governs the resonant frequency of the antenna. In view of design, selection of the patch width and length are the major parameters along with the feed line depth. Desired Patch antenna design is initially simulated by using IE3D simulator. And Patch antenna is realized as per design requirements. With this design slightly modified, dual band frequencies can be obtained. In this thesis, the resonant frequency is 2.4 GHz. At first, the dimensions of the rectangular patch antenna have been calculated. With those quantitative results then the simulation has been done. While doing simulation in practical case there has been a slight deviation in the desired frequency bandwidth. An optimization was taken to the dimensions for re-establish the frequency band at 2.4 GHz.
Design and Simulation of an Aircraft & Missile System & Optimal Tuning of both Using Pid & Differential Algorithm (DE)
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Shahin, Md. Zahidul Islam; Iftekhar, Ahmed Tashfin; Mahmud, Tanvir Hassan
This thesis tries to develop a model for the missile and for the aircraft simply using those dynamic force model and transfer function and to explore the potential of using soft computing methodologies such as Evolutionary algorithm(EA) –Differential algorithm(DE) in controllers and their advantages over conventional methods. PID controller, being the most widely used controller in industrial applications, needs efficient methods to control the different parameters of the plant. This thesis asserts that the conventional approach of PID tuning is not very efficient due to the presence of nonlinearity in the system of the plant. The output of the conventional PID system has a quite high overshoot and settling time. Two problem has been taken from a paper which has been considered as the dynamic model for missile and aircraft ,based on those problem the project progress. The main focus of this project is to apply evolutionary algorithm such as differential algorithm to design and tuning of PID controller to get an output with better dynamic and static performance. The application of differential algorithm(DE) to the PID controller imparts it the ability of tuning itself automatically in an on-line process makes it give an optimum output by searching for the best set of solutions for the PID parameters. The project also discusses the benefits and the short-comings of both the methods. The simulation outputs are the MATLAB results obtained for a step input .
Design and test of ds89s52 based trainer board
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-10-15) Quader, Md.Irfanul; Zaman, Tanzeeb; Islam, Yazdani Ul
The main difference between a microprocessor and microcontroller is that a Microcontroller has inbuilt peripherals like Timers, USART, Interrupt controller etc whereas in a Microprocessor these have to be interfaced as separate ICs. In this project we use the Microcontroller AT89s52 from the ATMEL corp. The AT89s52 is a low power; high performance CMOS 8-bit microcontroller with 4Kbytes of Flash programmable and erasable read only memory (EPROM) .The device is manufactured using Atmel’s high density nonvolatile memory technology and is compatible with the industry standard MCS-51 instruction set and pin out. The on-chip Flash allows the program memory to be reprogrammed in-system or by a nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash on monolithic chip, the Atmel At89s52 is a powerful microcomputer which provides a highly-flexible and cost effective solution to many embedded control applications.
Design of microcontroller based baby incubator
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Abid, Fahim; Patoary, Shajjied Hossan; Rahman, Md. Salman
Infant incubator provides a controlled environment for newborns needing special care, such as those born prematurely. By placing an infant in an incubator, doctors and nurses can set and monitor different aspects of the child’s environment in order to create ideal conditions for survival and moreover it protect infants from pollutants and infection. Infant incubators and other advances in medical technology have made it possible for small or premature babies to survive in higher numbers than they did in the middle of the 20th century. Design and development of microcontroller based temperature and humidity controller for an infant incubator monitors and controls these two parameters constantly which are very critical for the normal growth of the new born (premature) babies In this thesis work, focus has been to develop: 1. Hardware for temperature and humidity control 2. Compatible software This system can automatically control the infant’s temperature at optimum level usingPID concept and to maintain high relative humidity so as to minimize the thermal loss. The developed system must be user friendly, cost effective and accurate.
Efficient design of sum product decoding in log domain for LDPC codes in wireless network
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Rashid, Tahmid; Refayet, Sami; Ovee, Shahriar Arefin
A coding and modulation technique is studied where the coded bits of an irregular low-density parity-check (LDPC)code are passed directly to a modulator .At the receiver, the variable nodes of the LDPC decoder graph are connected to detector nodes, and iterative decoding is accomplished by viewing the variable and detector nodes as one decoder. The code is optimized by performing a curve fitting on extrinsic information transfer charts. Low Density Parity Check Codes (LDPC) gives groundbreaking performance which is known to approach Shannon‟s limits for sufficiently large block length. Historically and recently, LDPC have been known to give superior performance than concatenated coding. In this paper we propose a very simple but powerful method for the Sum Product decoding of LDPC codes. A simple, yet effective decoding algorithm is proposed for low-densitya parity-check (LDPC) codes, which significantly simplifies the check node update computation of the optimal sum-product algorithm. It achieves essentially optimal performance by applying scaling in the decoder‟s extrinsic information. If no such scaling is applied, then the proposed algorithm has small performance degradation. Our method improves the performance of the existing log-domain sum product coding. This is done by introduction of a difference to sum ratio factor, in the check to bit node updating process. In this paper we compare the two methods and show that our proposed algorithm is better than the existing one. Our proposed algorithm gives us better signal to noise ratio for a reasonable complexity. Simulation results demonstrate that the proposed algorithms are effective in imparting a better performance in terms of a lower bit error rate (BER) at medium to high signal to noise ratio (SNR) when compared to the traditional sum product algorithm while adding fair amount of complexity
Electrical and magnetic transport properties of Iron-based metallic glass (FINEMET)
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Muhammad, Deen; Farabi, Hussain Muhammad; Alam, MD. Jubaer
Electrical and Magnetic transport properties of Fe78B10Si12 (FINEMET) metallic ribbons prepared by standard melt-spinning technique have been investigated. Fe78B10Si12 shows conventional anisotropic magneto resistance (MR) which is found to vary from 0 - 15% with the external magnetic field. An external transducer is used to vibrate the sample in an external magnetic field and to investigate the dynamic behavior of the sample. It is observed that a small self-induced ac voltage is super imposed on the dc response of the sample. This small ac signal is observed to be periodic in nature and may be attributed to the presence of non-magnetic metallic species in the ribbon. The effect of temperature (ranging from 30o- 550o) on the resistivity of the sample is measured and the glass transition temperature, Tg of the alloy is estimated from the dc resistivity anomaly observed at the elevated temperature. The frequency dependent response of impedance, phase angle, permeability, permittivity, Quality factor, Dissipation factor are also studied by Wayne Kerr Impedance Analyzer with frequency range of 100Hz-100MHz. The observed electrical and magnetic properties of the material indicate that the alloy in its ribbon form is suitable for its potential use in electrical and magnetic switching devices.
Electricity Sustainability and Nuclear Power: Perspective Bangladesh
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Reyadul, Islam Mahmud; Hasan, Khan Jabid; Shahriar, Md Shihab
Adequate and quality electricity at an affordable price is a key element for socio-economic development of a country. Electricity is secondary or delivered form of energy produced from the primary sources e.g. fossil fuels, fissile materials, and renewable sources like hydro, wind, solar, tide, geothermal, bio-mass, ocean current etc. About 65% of global electricity currently is produced from fossil fuels: coal, gas and oil. The reserves of the fossil fuels are finite, geographically not uniformly distributed and in some counties the reserves are maturing. The prices of fossil fuels often fluctuate partly due to demand and supply imbalance and partly on geopolitics. The use of fossil fuels release enormous amount of greenhouse gases resulting global warming and climate change. Environmental pollution and transportation of large quantities of fossil fuels for bulk electricity generation are also issues of concerns. The thesis primarily presents electricity and nuclear power from the perspective of sustainability. Bangladesh scenario has also been touched.
Fabrication and Characterization of a Nano Crystalline Natural Dye-Sensitized Solar Cell and Design of an Artificial Solar Simulator
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Anam, Khairul; Haque, Radif Rildad; Asif, Omar
The present thesis investigates the performance of a dye-sensitized solar cell (DSC) under both idealized and outdoor conditions. Different electrical behavior under varying compositions of TiO2 is found. An understanding of the cell behavior with respect to the change in different compositions of TiO2 paste has been sought by experimental investigations and following data analysis. The efficiency, behavior of the cell with different molarity of acid, effect of using industrial grade TiO2 instead of laboratory grade TiO2, life time of the cell with variation of the film thickness of electrolyte are also carried out in this chapter. The performance of Red Spinach (Amaranthus cruentus) has been investigated for the first time ever. The experimental investigations have been carried out in the laboratory under controlled conditions and the influence of one performance parameter could be determined. The cells investigated show very different electrical behavior under varying conditions. An artificial solar simulator has been built using a 450W Xenon lamp that produces a light of intensity from 200W/m2 to 1200W/m2. It has been made using all the cheap materials available in Bangladesh. The system can produce AM 1.5G which is the standard to measure the solar cell performance in a condition with no sunlight. The main purpose of making this solar simulator is to measure cell performance under AM 1.5G as most of the time around the year it is very difficult to get continuous solar radiation of 1000W/m2 in Bangladesh.
Fuel Cell Inverter System: A Sustainable Energy Source
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Rahman, Md. Mostafizur; Rahman, Md. Ashifur; Hossain, Md. Shafayet
The necessity of new or alternative power sources gives rise to the fuel cells which can be sustainable energy sources. The research and development in the area of fuel cells are becoming popular day by day due to their various advantages. But the conversion process needs to be modified to connect the fuel cells to the grid. The dc voltage from the cells should be efficiently converted to ac as the voltage gives higher amount of fluctuation. New types of inverters like Z-source inverters which are efficient, EMI noise free and employed to reduce the ac output voltage fluctuation can meet these demands. This type of inverters also eliminates the necessity of additional boost converters. This paper tries to develop an adaptive control mechanism of the Z-source inverters using DSP board (DS- 1104) so that a quality power from fuel cells can be supplied to the grid.
Introduction, Characterization and Efficiency Optimization of an AlxGa1-xAs / AlxIn1-xAs Heterojunction Solar cell with GaxIn1-xAs Back Surface Field (BSF) Layer Using ADEPT/F
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Haque, K.A.S.M. Ehteshamul; Ferdaous, Mohammad Tanvirul; Quddus, Tahmid Nahian Bin
Energy conversion efficiency is a major issue for photovoltaic cells today. Researchers are continuously trying to improve the efficiency level of photovoltaic devices by introducing new materials and advanced concepts. The target is to reach a high efficiency level within affordable cost, which will lead to a mass generation of electricity using photovoltaic devices. In this work, a III-V heterojunction solar cell has been introduced and characterized, which uses an AlxGa1-xAs/AlxIn1-xAs heterojunction as the working p-n junction. ADEPT/F, a 1D simulation software, was used throughout the whole work for the simulation of light J-V characteristics for different designs. Energy conversion efficiency for each design was calculated from its corresponding light J-V characteristics curve. An illumination level of 1000 W/m2 (AM1.5G standard) and a concentration level of 1 sun was considered for all the simulations in the work. The photovoltaic cell has an n-on-p structure, where the n-type Al0.7Ga0.3As (x=0.7) layer acts as an emitter, and the p-type Al0.48In0.52As (x=0.48) layer serves as the base (absorber). The base thickness was kept at 10 μm in the first simulation, and an energy conversion efficiency of 6.78% was obtained. Then, a lightly doped third layer (p-type) of Ga0.67In0.33As was introduced (in contact with the base layer). This resulted in an efficiency of 15.3%, which was further increased to 16.79% after allowing a very high doping level (1×1019 cm-3) in the Ga0.67In0.33As layer. Germanium (Ge) substrate (p-doped) was used for the structure. Afterwards, efficiency variation with change in device parameters (layer thickness and doping concentration) was investigated for the device. Variation in efficiency was plotted against a particular changing parameter, keeping every other parameter fixed at some default value. After analysing the variation curves, two optimized designs were proposed, which yield 19.57% and 20.56% efficiency, respectively. In the later part of the work, variation in energy conversion efficiency was studied by changing the alloy composition at different layers of the device. Simulations were done for different combinations of alloy composition at device layers. The study was conducted by analyzing the efficiency values resulting for different combinations. The best results were obtained for x= 0.9, 0.48 and 0.9 in the top, middle and 9 bottom layer, respectively. For optimized values of layer thickness and doping concentration at different layers, this particular combination of alloy composition yielded an efficiency of 21.39%. This particular design for the device had some drawbacks in practical fabrication. These drawbacks were addressed with appropriate solutions, and a number of changes were brought in the highest efficiency design. The modified design, which is fully feasible for fabrication, yields an efficiency of 17.03%. Considering the high fabrication cost of III-V solar cells, a thin film solar cell design was proposed, which is only 2 μm thick (excluding the substrate thickness), and yields an efficiency of 12.16%. This efficiency was raised to 13.84% by using InP substrate, instead of Ge.
Linear and non linear controller design for DC-DC converter
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Aslam, Muhammad Faizan; Fateh, Saif-Al-Islam; Anwar, Muhammad Usman
DC-DC power converters play an important role in powering telecom and computing systems. With the speed improvement and cost reduction of digital control, digital controller is becoming a trend for DC-DC converters in addition to existed digital monitoring and management technology. In this thesis, digital control is investigated for DC-DC converters applications. To deeply understand the whole control systems, DC-DC converter models are investigated based on averaged state-space modeling. Considering Buck DC-DC converter, the thesis takes it as an example for digital control modeling and implementation. In Chapter 2, unified steady-state DC models and small-signal models are developed for DC-DC buck converters. Based on the models, digital controller design is implemented in Chapter 3. In Chapter 4, Fuzzy logic control is introduced and based on that knowledge Fuzzy controller is designed for the control of buck converter. It should be noted that Fuzzy logic control provides superior performance than conventional PI and PID controller especially during under load transient condition.
LTE Radio Parameters and Network Planning
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Harouna, Mugumya Twarik; Muhammed, Rammah; Salele, Na fiu
The ever growing need for data transmission capacity drives the network service providers to build Mobile LTE networks in the urban areas. The 3GPP LTE is the evolution of the UMTS in response to ever-increasing demands for high quality multimedia services according to users' expectations. LTE promises to deliver an unrivalled user experience with ultra-fast broadband and very low latency and at the same time, a very compelling business proposition for operators with exible spectrum bandwidth, smooth migration and the ability to deliver low cost per bit voice and data services. LTE is designed to have wider channels up to 20MHz, with low latency and packet optimized radio access technology. The peak data rate envisaged for LTE is 100 Mbps in downlink and 50 Mbps in the uplink. LTE has very promising features, like bandwidth scalability and both FDD and TDD duplexing methods. This thesis introduces the radio parameters required for e cient LTE radio network planning through numerous simulations, and then after we establish a radio network using Dhaka as a case study
Microcontroller Based Joystick Controlled Wheelchair
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2012-11-15) Mahmud, Md. Salek; Rahman, Towfiq-ur-; Hossain, Md. Delwar
When people are unable to walk properly due to old age or as a result of some accident or paralysis due to stroke they may often lose their ability to control their movement and means to travel from one place to another.The prime objective of this research was to develop a prototype system which can provide mobility assistance to individuals.This thesis investigates the method of locomotion via a wheelchair which is controlled using input from a joystick and is analyzed via a microcontroller and out drives the motor. This thesis also consider the design consideration of a simple, low cost battery driven wheelchair where the control is achieved using a microcontroller. Two dc motors are differentially driven using PWM signal from microcontroller which provide easy control over speed and direction. There are further proposed design consideration which includes self-sustaining power supply using PV cells with the wheelchair and also long distance wireless control and use of sensors for autonomous control of the wheelchair.