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التشوه بالتوافقيات في اشارات التدفق للمتحسس السعوي الحيزي المثبت خارجيا == Harmonic Distortion In The Flow Signals of Externally Mounted Capacitive Spatial Filter

Author name: مروه مالك حسوني
Supervisor name: عباس احمد الشالجي
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: This thesis investigates the performance of some windows on the flow signals that are generated from the planar capacitance spatial filter (PCSF) according to the moving of the solid particle in the channel of the filter. The sensor that operates as non - invasive device for solid flow measurement utilizes the thin wall of a dielectric pipe section as a shielding layer to protect the sensor from erosion, rust and moisture, and to make it more versatile.The finite - difference model equations are solved using successive over relaxation (SOR) methods. The waveforms show that the response of the PCSF is spatially - biased towards particle flowing closer to the plane of sensing electrodes and that the resulting flow signal is non - sinusoidal. The SOR method that is used to compute the PCSF potential fields has been investigated using a mesh of 110 by 32 nodes, and the algorithm was programmed in MATLAB (Release 2013a) using an Intel core ™ i3 PC,CPU processor.To study the effect of the total harmonic distortion (THD) content on the flow signals that are calculated with respect to the fundamental frequency of the power spectrum density through a specific quantitative criterion, this work comprises a comparative study among three types of windows; Hanning, Hamming, and a subOptimal window called the Kaiser window.The effect of particle flying heights, relative permittivity and size on the THD of the flow signal were examined. It was found that theTHD of flow signals at heights closer to the plane of sensing electrodes is high and decreasing gradualy when the particle flying height is far above the sensor. All the three windows used in this work have better suppression of harmonics distortion as compared with unwindowed (raw) flow signal.

تمثيل وتنفيذ العاكس ثلاثي الطور رباعي السيقان بواسطة طريقة المتجه الفضائي بتضمين عرض النبضة == Modeling And Implementation of Space Vector PWM Four - Leg Three Phase Inverter

Author name: لؤي كمال عبد القادر
Supervisor name: فاضل عباس مهدي القرملي
Specific topic: Electrical Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: The thesis considers a three - phase four - leg inverter, which is used to supply unequal loads without using a transformer. In the literatures, a three - dimensional modulation technique, requiring complex mathematical algorithms were proposed for this kind of inverter. In this research a different approaches are discussed through two kinds of controller; first type is based on the separation control method of the fourth - leg of the inverter from the other phases for one type for modulation. This research applied to the three - phase inverter of the traditional SVM techniques avoiding the employment of complex procedures. The voltage modulation method based on a triangular carrier waveform for the three - phase four - leg voltage source converter. The four - leg converter can produce three - phase output voltages independently from the additional forth - leg. The proposed modulation method for the four - leg inverter is implemented with a single carrier by a simple useful “offset voltage” concept. The second type is equivalent to the so - called three - dimensional space vector PWM method, but its implementation is much easier. The simultaneously synthesized equations of the maximum magnitude of unbalanced three - phase voltage.The feasibility of the proposed modulation technique types verified by computer simulation and experimental results. These results show that both types of “Carrier - Based Pulse Width Modulation (PWM) technique” and “Three Dimensional Space Vector Modulation Technique” are easier implemented than conventional type by using microcontroller component (PIC16F874A/877A) instead of digital components (DSP & FPGA). So this thesis offers a prototype for this circuit with low cost and low harmonics, but with more complex control circuit.

تحليل الاتصال بين القمر الصناعي والطائرة باستخدام نموذج تعقب الشعاع == Analysis of Satellite - To - Aircraft Communications Using Ray Tracing Model

Author name: علي محمد علي
Supervisor name: جابر سلمان عزيز
Specific topic: Communications Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: While the aircraft flying above the earth surface, the signal transmitted from the satellite to the aircraft suffered from changes in it's characteristics at the aircraft receiver's antenna according to many factors affecting the direct and reflected power from the earth surface such as the distance difference, the nature of the earth surface, elevation angle, Doppler shift, etc… This Thesis introduces a proposed algorithm to analyze and simulate the communication link between the Satellite and the aircraft taking into account all the parameters that affect the magnitude of the power and signal characteristics received at the aircraft antenna. The proposed method uses the ray - tracing technique in this simulation to analyze the communication link between the Satellite and aircraft. The simulation developed in this thesis has minimized the error percentage as much as possible taking into account most of the factors that might affect the characteristics of the signal received by the aircraft from the satellite. This simulation considers the free space loss, specular reflection losses, scattering factor, earth curvature effect, etc…,also the simulation takes into account the Doppler effect that caused by the aircraft movements. The simulation measures the received signal strength and fading characteristics of satellite to aircraft communication to determine the effectiveness of communication and to establish parameters which can be useful to the communication system designer in Iraq and the rest of the world. MATLAB® v6.5 used in the simulation as application software, the simulation also applied to MATLAB® v7.0.

تحليل المسار النازل لنظام الاتصال اللاسلكي التكيفي المتعدد المداخل والمخارج والمستخدمين == Analysis of Adaptive Downlink Multiuser Mimo Wireless Communication System

Author name: عمر جبار ابراهیم
Supervisor name: رعد سامي فياض
Specific topic: Communications Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: Multiple - input multiple - output (MIMO) wireless communication systems have received significant attention due to their enormous channel capacity potential in rich scattering environment. Such systems need to consider multiuser transmission / reception in their design. This thesis investigates theoretically the ergodic capacity of multiuser MIMO systems operating with adaptive techniques to enhance their performance. The ergodic capacity of multiuser MIMO system is analyzed and simulated for three types of channels : additive white Gaussian noise (AWGN) channel, uncorrelated Rayleigh fading (URF) channel, and semicorrelated Rayleigh fading (SRF) channel. The downlink SRF channel for each user is modeled by assuming that the fading is correlated at the transmitter but uncorrelated at the receiver side. The simulation results are compared to those related to a single - user system and used as a guideline to present an adaptivetechnique to enhance the capacity of MIMO system operating in SRF channel. The adaptive technique is based on a tradeoff between time division multiple access (TDMA) and block diagonalization (BD).Simulation results are presented using MATLAB environment to address the dependence of ergodic capacity of a MIMO communication on various system and channel parameters. The results indicate clearly that the threshold level of angle between users ? employed in the adaptive system must be chosen carefully to maximize the ergodic capacity. The optimum threshold ?th is equal to 24°, 42° and 47°, for angle spread ? = 5°, 50° and 75°, respectively

طرائق الكشف للتضمين الترددي المتعامد للرابط النازل في نظام تطور طويل الامد (LTE) == Detection Methods For Ofdm Downlink In Long Term Evolution (LTE) System

Author name: اكرم جبار عبد الحسين حسن
Supervisor name: يمان اسماعيل مجيد
Degree: Master
University: University of Baghdad
Language: English
University location: Baghdad
First pages:
Abstract: GPP3 التطور على المدى الطويل (LTE) هو تقنية الجيل الرابع اللاسلكية ذات النطاق العريض. هدفه الرئيسي هو تعزيز الكفاءة الطيفية باستخدام تقنيات التضمين الترددي المتعامد بالتقسيم (OFDM). ومع ذلك، ياتي هذا التحسن في الاداء بزيادة التعقيد الحسابي في اجهزة الاستق | 3GPP Long Term Evolution (LTE) is the fourth generation mobile wireless broadband technology. Its key objective is to enhanced spectral efficiency by using Orthogonal Frequency Division Multiplexing (OFDM) techniques. However, this performance improvement comes at the cost of increased computational complexity in the receiver. The goal of this work is to introduce a detection method that gives a better performance with reasonable computational complexity for LTE mobile communication system. An approximated linear baseband model for the two modulation techniques used by the LTE system (which is the Quadrature Phase Shift Keying (QPSK) and sixteen - level Amplitude Modulation (16 - QAM)) have been derived. Three receivers have been simulated and tested. The three receivers use Least Square (LS) channel estimator. These receivers uses channel compensator, decision feedback equalizer and perturbation algorithm. The LTE communication system has been simulated using MATLAB®7 programming language. The results of the computer simulation show that the perturbation algorithm gives an enhancement in the receiver performance of about 2 dB in different mobile channels than decision feedback equalizer and about 5 dB than channel compensator at the 10 - 3 of BER.

بناء خوارزمية تزامن لانظمة (OFDM) باستخدام معالجة الاشارة الرقمية == Dsp - Based Synchronization Algorithm Implementation For OFDM System

Author name: رائد ستار جبر
Supervisor name: محمود عبد القادر عبد الستار
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: تعدد الارسال للتردد بالتقسيم المتعامد (OFDM) هو مفتاح تمكين التكنولوجيا لمعظم انظمة الاتصالات اللاسلكية الحالية ذات معدل نقل البيانات العالي. والميزة الرئيسية للـ (OFDM) مقارنة بالطرق التقليدية هو انه يحول القناة ذات النطاق العريض الى قنوات فرعية ضيقة متو | Orthogonal Frequency Division Multiplexing (OFDM) is the key enabling technology for most current high data - rate wireless communication systems. The primary advantage of OFDM over conventional schemes is that it converts a wideband channel into parallel narrowband sub - channels allowing relatively simple channel estimation and frequency domain equalization. It is as an effective technique for coping with channel impairments like multipath propagation and Inter Symbol Interference (ISI) by making use of an appropriate cyclic prefix. One of the major drawbacks of OFDM is that it is more sensitive to synchronization errors than its single carrier counterparts. This thesis describes a real - time implementation of a timing and frequency synchronization for OFDM system using MATLAB software Simulink, DSP processor TMS320C6713 and Code Composer Studio (CCS). The hardware interface converts the baseband signal from the PC to the DSP Processor. Basic transmission and reception performances are evaluated in real time using Real Time data Transfer (RTDX). The practical results and performance evaluation of the synchronization algorithms in OFDM system is presented and discussed. The results are plotted for different offsets of CFO and STO with different values of signal to noise ratio. Also the bit error rate (BER) and the mean square error (MSE) of the system is analyzed. The results show that the time offset more effect than frequency offset because of ISI and ICI occurs when time offset occur in the system. The synchronization algorithm is found to be robust for both CFO and STO simultaneously. It can handle offset of about CFO = 500 Hz and STO = 14 samples simultaneously without wasting extra bandwidth. This algorithm used for synchronization more robust for 16QAM compared with 4QAM modulation.

التركيب السليكوني النانوي في الخلايا الشمسية == Nanostructured Silicon Based On Solar Cells

Author name: نور احمد سلمان
Supervisor name: ثائرة زكريا الطيار
Specific topic: Electronic Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: تعتبر الخلايا الشمسية تكنولوجيا واعدة وقابلة للتجديد حيث ازداد الطلب عليها نتيجة لزيادة الاهتمام بالطاقة الكهروضوئية. ان التحسين المستمر لكفاءة الخلايا الشمسية بايجاد التقنيات والمفاهيم الجديدة يجب ان يمتد على نحو متزايد باعتبارها واحدة من اهم مصادر الط | The demand for solar cells has been growing rapidly with an increasing social interest in photovoltaic energy. The improvement of energy conversion efficiency of solar cells is performed by developing the technology and concepts that have been increasingly extended as one of the key components in our future global energy supplement. But, the main problem of photovoltaic modules are their rather high production and energy cost. Three generations of solar cell technologies have been established in the previous century.Nanostructured silicon substrates based on p - type crystalline Silicon (c - Si) have been prepared in this work. Electrochemical Etching (ECE) of the Silicon (Si) wafers in Hydrofluoric (HF) acid was employed to synthesize porous layers consisting of silicon nanostructures. The process was carried out at different etching time and different current densities which are considered as effective parameters in ECE process. It is found that a homogeneous porous layer could be obtained with porosity value of (87%) when the current density is (60 mA/ cm2) and the etching time of (10 min). Among the Transparent Conductive Oxide (TCO) materials available, Zinc Oxide (ZnO) films show promising electrical and optical properties in combination with low cost alternatives. It can function as Anti - Reflecting Coating (ARC), window material, transparent electrode and active layer in heterojunction solar cells. n - type ZnO thin films are grown on p - type nanostructured silicon substrates by using Pulsed Laser Deposition (PLD) technique with Q - switching Nd : YAG laser beam Second Harmonic Generation (SHG) [?=(532 nm), number of pulses (140) pulses, and laser energy (820 mJ)], vacuum of (10 - 3 Torr), ambient oxygen pressure of (10 - 1 Torr), and substrate temperature of (400 °C). The morphological, optical, chemical and structural properties were investigated using Atomic Force Microscopy (AFM), Ultraviolet - Visible (UV - VIS) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, and X?Ray Diffraction (XRD) techniques, respectively.Surface morphology and optical properties results show densely packed highly crystalline growth of ZnO thin film on nanostructured silicon substrate grown at optimum condition with an average grain size around (88.57 nm). The average roughness, root mean square, and ten - point height estimated from AFM quantitative analysis, are found to be (3.02 nm), (3.62 nm), and (8.76nm) respectively. The thickness is calculated and found to be (100 nm). The film shows high transparency (above 80%) and the estimated Energy - gap (Eg) is found to be about (3.4 eV). This is important for its applications as transparent conductive films and solar cell windows. The chemical and structural properties results characterize ZnO at (420 cm - 1) and (766 cm - 1) absorption bands respectively and the thin film is polycrystalline with hexagonal Wurtzite structure.

محاكاة GSM/EDGE وGSM لنظام الاتصالات المتنقلة == Simulation of GSM And GSM/EDGE Mobile Communication Systems

Author name: اسامة علي عبد الله
Supervisor name: رعد سامي فياض
Specific topic: Communications Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: The introduction of global system for mobile communication (GSM) air interface has undoubtedly created a new area in telecommunications. In view of its extensive use in real world applications, it is highly desirable to further investigate the performance of the GSM system under different operating conditions and environments. Furthermore, there is increasing interest in using high - level modulation to provide enhanced data rate for GSM evolution (EDGE).This thesis investigates the performance of both GSM and GSM/EDGE systems operating in Raleigh fading channel. The results are reported for different models of fading channel in order to describe various environments. A detailed SIMULINK model is developed in MATLAB environment to simulate the GSM system. Furthermore, a MATLAB software package is developed to simulate extensively the EDGE system. Both simulation models are handled to characterize each essential part in these systems. The simulation takes into account channel coding, modulation type, interleaving and burst building, multipath channel effect, channel estimation, and detection process.The simulation results indicate clearly that to achieve a bit error rate (BER) of 1x10P - 5 P in additive white Gaussian noise (AWGN) channel, the signal - to - noise (SNR) ratio should be 5.25, 3.75 and 12.25 dB when GSM, MCS - 1 EDGE (GMSK modulation), and MCS - 7 EDGE (3?/8 - 8PSK modulation) systems are used , respectively. These values are to be compared with R12R.43, R1R0.21 and R2R1.05 dB, respectively, for HT100 - type fading channel. The MSC - 1 system offers the best BER characteristics followed by GSM system. The MCS - 7 offers the worst BER characteristics among the three systems.

تصميم وتنفيذ ذراع الي موجه عن طريق اشارة تخطيط العضلات باستخدام المتحكم الدقيق == Design And Implementation of A Robot Arm Driven By EMG Signal Based On Microcontroller Unit

Author name: انس عبد الحميد كاظم
Supervisor name: خالدة شعبان رجب
Specific topic: Electronic Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: تعتبر اشارة (EMG) هي الاشارة المكتشفة على سطح الجلد فوق العضلة والمتولدة من مصدر المجال الكهريائي عند التقلص العضلي. الاشارة العضلية بصورة رئيسية في مجالين : تشخيص الخلل العضلي واشارة تحكم لسياقة ذراع الي، يستخدم الذراع الالي المساق بواسطة الاشارة العضلي | Electromyogram (EMG) is a signal detected on the skin above a muscle and generated by sources of electric field within the muscle during contraction. EMG signal is used mainly in two fields; Muscle disorder diagnostic and control signal for driving robotic arm. The robot arm driven by EMG is used as a remote control in hazard places or as prosthesis part for limbs of disabled. The first part presents placing array of EMG electrode on two muscles and measure the EMG signal, design acquisition circuit to optimize the EMG signal for two muscles; hardware circuit that designed will eliminate the noise resulting from cable, electrodes, 50Hz and aliasing. In order to monitor and record EMG signal, Data Acquisition System (DAQ) is designed for this purpose using Arduino platform, which gives the ability to deal with signal. The real time signal was taken from three persons with different weights and ages. The second part includes a proposed design of digital filter with windowing and applying to real time signal to compare the results for many times of orders and types of windowing in order to meet the best criteria. The FIR filter with 8th order will be chosen as digital filter with Hann windowing that is apply to eliminate the EMG noise that is caused from many sources and results optimum EMG signal that is used to control robot arm, implementing digital filter characteristic into dsPIC30F4013 which it signal processing microcontroller and using the filtered signal to control the robot arm by interfacing with DC driver to drive robotic arm with two degrees of freedom (2 - DOF). Also, this part includes the technique which simulates the results using MATLAB 2011a to control the movements of the robotic arm. Micro C for dsPIC© is used to write C code for FIR digital filter and loops with control algorithm to enable the controlling robot arm.

تقليل التاثيرات اللاخطية في منظومات التقسيم المتعدد للطول الموجي العالية الكثافة == Mitigation of Fiber Nonlinearity Effects In Ultra High - Dence WDM System

Author name: سيف حسام عبد الواحد
Supervisor name: علي يوسف فتاح
Specific topic: Communications Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: The optical signal is severely degraded when transmitted in the fiber due to both the linear and nonlinear distortions. It is well known that, the linear distortions in single mode fiber include chromatic dispersion (CD) and polarization - mode dispersion (PMD) while self - phase modulation (SPM), cross phase modulation (XPM) and four - wave mixing (FWM) are considered the most among nonlinear distortions. To deal with the nonlinear impairments, a number of techniques, such as electronic equalization, pre - coding, digital back - propagation(BP), pre - chirping, optical phase conjugation (OPC) and nonlinearity management, are developed and improved. In the present work, a method called Fractional Fourier Transform (FRFT) has been applied to mitigate fiber nonlinearity impairments. The Fractional Fourier Transform is a time - frequency distribution and an extension of the classical Fourier transform. Time domain FRFT can be implemented by using time lens according to the optical time - space duality theory. The modulated optical pulses will be pre - distorted by an FRFT module before being launched into fiber links. In this work, 10 Gb/s optical fiber system with five spans, each of length 60 Km, for three types of modulation formats (Return - to - Zero Differential Phase Shift Keying (RZ - DPSK), Return - to - Zero Differential Quaternary Phase Shift Keying (RZ - DQPSK) and Carrier - Suppressed Return - to - Zero (CSRZ)), single and multi - channel transmission systems are designed and simulated using “OptiSystem (2011) version 10.0” software package. In order to analyze the transmission performance of the simulated systems without and with FRFT, a set of eye diagrams, optical spectrum visualizers, Q - factor versus input power and Bite Error Rate (BER) versus Signal to Noise Ratio (SNR) curves are presented to evaluate the influence of FRFTon the system performance. For CSRZ modulation format the Q - factor for single channel system at 0 dBm (input power) was 43.5 without FRFT and 78 with FRFT. The BER of sixteen channel system (channel No.8) at bit rate 10 Gb/s per channel, 300 Km link length of CSRZ modulation format with channel spacing of 50 GHz at SNR 10 dB without FRFT is 10 - 4.8 and 10 - 7.4 with FRFT. The BER of thirty two channel system (channel No.16) at bit rate 10 Gb/s per channel, 300 Km link length of CSRZ modulation format with channel spacing of 50 GHz at SNR 10 dB without FRFT is 10 - 4.6 and 10 - 6.4 with FRFT. The BER of thirty two channel system (channel No.16) at bit rate 10 Gb/s per channel, 300 Km link length of CSRZ modulation format with channel spacing of 25 GHz at SNR 10 dB without FRFT is 10 - 2.56 and 10 - 3.24 with FRFT.

تاثير اللاخطية في الالياف البصرية على اداء نظام تجميع الاطوال الموجية الضوئية المنقسمة باستخدام تقنية الاستقطاب المزدوج لتقسيمات التردد المتعامد الضوئي == Effect of Fiber Nonlinearity On The Performance of WDM Optical Systems Using Dual Polarization CO - OFDM Technique

Author name: بشار مظفر احمد
Supervisor name: رعد سامي فياض
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: The implemented existing high capacity optical networks are based on 50 GHz wavelength - division multiplexing (WDM) channel spacing and carry up to 50 Gb/s data rate per channel. In recent years, there is increasing interest in using dual - polarization (DP) technique to enable future systems with at least 100 Gb/s rate per channel to operate over existing optical networks. The performance of these advanced systems can be enhanced further by using coherent optical orthogonal frequency division multiplexing (CO - OFDM) technique which offers high spectral efficiency and outstanding tolerance of fiber dispersion.This thesis addresses the effect of fiber nonlinear optics on the performance of dual polarization CO - OFDM/WDM system operating with 100 Gb/s per channel. Different modulation formats, namely BPSK, QPSK and 16 - QAM, are used. First, the performance of a single - channel system is investigated in the absence and presence of fiber nonlinearity. The results are compared with those of a conventional (single - polarization) system to identify the key role played by the DP technique. The investigation is then extended to WDM systems incorporating DP - OFDM technique. The results reveal that the effect of fiber nonlinearity can be reduced or cancelled by using optimum transmitter laser power Popt. Further, the value of Popt is a function of transmission distance,number of multiplexed channels, and modulation formats. Popt of - 11, - 12, and - 5 dBm is needed for a ten - channel DP system operating with BPSK, QPSK, and 16 - QAM formats, respectively.Simulation results presented in this thesis are obtained using OptiSystem (version 11.1) which is a commercial software package.

الموقع الامثل للمعوض التزامني الثابث لشبكة الضغط الفائق العراقية باستخدام الخوارزمية الجينية == Optimal Location of Static Synchronous Compensator (STATCOM) For Iraqi National (400kV) Super High Voltage Grid Using Genetic Algorithm

Author name: حسن علي عبد المجيد سلبي البياتي
Supervisor name: Firas Mohammed Tuaimah
Specific topic: Electrical Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: Transmission networks of modern power systems are becoming increasingly stressed because of the growing demand and restrictions on constructions new lines. One of the consequences of such a stressed system is the threat of losing stability following adisturbance. Flexible AC Transmission System (FACTS) devices are found to be very effective in a transmission network for better utilization of its existing facilities without sacrificing the desired stability margin.The Static Synchronous Compensator (STATCOM) is a shunt device which employs one of the latest technologies of FACTS and power electronic switching devices in electric power transmission systems to control the voltage and power flow. The STATCOMregulates the voltage at its terminal by controlling the amount of reactive power injected into or absorbed from the power system.Whilst the Iraqi National (400 kV) Super High Voltage Grid System suffers from voltage stability problems because of the high variation in the reactive power conditions all over the year seasons. Therefore, this thesis proposed an application of the STATCOM devices to maintain the voltages within the specified limits and enhancing voltage stability for all seasons in the year, as well as reducing the apparent power losses. And in order to reduce therequired installation cost of the STATCOM devices, this performance has been done by using minimum possible size of the reactive power injected or absorbed by the STATCOM devices, while satisfying the stability limits.The benefit of the STATCOM devices depends greatly on how these devices can be placed in the system. The general problem focused in this thesis was how to optimally determine the locations and the sizes of the STATCOM devices that to be installed. For thatreason, it was decided to follow an optimization approach such as a Genetic Algorithm (GA), which is one of the heuristic methods to find the optimum location and the value of installed STATCOM devices.The Newton - Raphson load flow method, with the proposed approach has been examined and tested first on the 5 - bus IEEE test system; the results obtained encouraged us to implement the same approach on the 27 - bus Iraqi National (400kV) SHV Grid System.The real data for Iraqi network have been taken from Iraqi National Control Center (INCC), in the Ministry of Electricity.computer program, written in MatLab environment, was developed to represent the proposed method.

خوارزمية جديدة لنظام اخفاء المعلومات == New Algorithm For A Steganography System

Author name: مروة جليل محسن
Supervisor name: اثير علاء صبري
Specific topic: Communications Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: This thesis presents a new steganographic algorithm for embedding encrypted secret image in grayscale and color images to provide high level security of data for communication over unsecured channels.The proposed algorithm combine the features of Cryptography and Steganography. The hidden secret message capacity, stego - image quality and security are three important conditions for data hiding technology. According to these requirements, an effective security protection with high hiding capacity steganographic algorithms are proposed based on frequency domain of the cover and the secret image.The proposed algorithm first analyzes the secret image into its frequency components using Discrete wavelet transform (DWT) , Wavelet packet transform(WPT) , Multiwavelet transform(MWT) , and slantlet transform(SLT) , respectively. Then the low frequencycomponent of the secret image is encrypted using Advanced encrypted standard (AES) method and then embedded in the insensitive mid and high sub - bands obtained from the cover image after applying these transformations (mentioned earlier) on it. The embedding method used in this thesis is LSB (Least significant bit ) method. The resulting stego image from different algorithms are then compared..The effectiveness of the proposed algorithm has been estimated by computing Mean square error (MSE) ,signal to noise ratio (SNR), Peak Signal to Noise Ratio (PSNR) and the capacity.The best algorithm is obtained by using 2level - DWT for cover image and 1level - DWT or WPT for secret image because the capacity of the hidden secret data and stego image quality are improved. The embedding image reaches to half the size of cover image at same time PSNR reach to 62 dB and MSE about 0.036 and this is better than many other existence algorithms.By both objective and subjective observations, the resultant stegoimage that will be transmitted does not draw any suspicion, so the main goal of steganography is achieved..The language used for testing the algorithms is MATLAB R2013a, with a computer of the following specification ; Processor : Intel(R) Core(TM) i5 CPU M430 @ 2.27GHz and RAM - 3GBytes.

اخفاء العلامة المائية الرقمية باستخدام تحويل الموجيات ذات عامل جودة قابل للتعديل == Digital Watermarking Based On Tunable Q - Wavelet Transform

Author name: هاجر احمد ابراهيم
Supervisor name: اثير علاء صبري
Specific topic: Communications Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: لقد دخلنا عصر حيث المعدات غير المكلفة متوفرة ويمكن من خلالها انتاج نسخ كاملة من المواد المتعددة الوسائط الرقمية مثل صوتيات بجودة القرص المضغوط ونشر صور عالية الجودة او مقاطع الفيديو الرقمية. من خلال هذه البيئة اصبح من السهل على الجهات غير المختصة انتاج ن | We have entered an era where inexpensive and readily available equipment can produce perfect copies of digital multimedia materials, such as CD - quality audio, publication - quality images, or digital video. In this environment, it has become easier for malicious parties to make salable copies of copyrighted content without compensation to the content owner.Many media content owners are concerned about the potential loss of revenue from multimedia piracy, especially when the content will be exposed to the Internet. Digital watermarking is seen by many as a potential solution to this problem.In this thesis, two proposed methods one for grayscale image watermarking and the other for color image watermarking are suggested. They require the original image for watermark extraction and they are belonging to the wavelet domain watermarking. They exploit the Tunable Q_Wavelet Transform. Therefore, different cases are performed to identify the best among them for the proposed application. As a result of the testing process, the best case is founded when ( Q=4, r=8, J=28). The first proposed method can be used with applications requiring high degree of imperceptibility and high security. The embedding process of this method is based on adding the pseudorandom watermark bits in the largest TQWT coefficient.The second proposed method is more robust against distortions than the first proposed method and is characterized by an acceptable degree of imperceptibility and high security. The embedding process of this method is based on adding the compound watermark image to the original color image.They are performed using MATLAB7 programming language. Different images are tested and the watermark is extracted exactly from the watermarked images.The Peak Signal to Noise Ratio “PSNR” using best case for the two proposed methods is found (77.97) dB for the first method and (51.14) dB for the second method.

تحديد منظومة كفوءة للقدرة الفوتوضوئية المستقلة بناءا على الاجواء العراقية == Investigation Into Efficient Stand - Alone Photovoltaic System Based On Iraq Climate

Author name: انسام صبحي جبار
Supervisor name: محمد مؤنس عز الدين
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: الطاقة الشمسية هي احدى الطاقات المتجددة التي تمتاز بانها امنة وصديقه للبيئة. عالميا هناك توجه كبير لهذة الانواع من الطاقات للحد من مشاكل التلوث والاحتباس الحراري. شهدت السنوات الاخيرة انخفاض في اسعار منظومات الطاقة الشمسية وكذلك ارتفاع كفائتها مما ساعد وب | Solar energy is safe as well as clean. It is one type of renewable energy , the energy does not cause pollutions and is not harmful to the environment. It is gaining importance now with the increases in global warming and pollution causing the adoption of renewable energy sources as alternative energy sources. For these reasons, the technological advance seeks to reduce the cost of renewable energy and increase efficiency to expand its reach.This work investigates the best strategy for design the solar energy system of stand - alone type. The stand - alone system consists of the PV array, maximum power point tracking, DC - DC converters, charge controller, battery, load and inverter. Standard specifications are used to ensure the successful operation of any system designed according to this method.The proposed method in this work includes calculation by using Microsoft Excel and simulation of long term periods especially during the autonomy days operation by using Matlab/Simulink. Many cases are studied, a suitable PV power system is introduced for each case. The results of the design of the case study are quite in agreement with published results.The objective of this work is to design solar energy systems for hypothetical loads according to Iraqi climate, this aim is achieved because the designed system passed many tests, especially for the worst case of operation. The investigation shows that the system is capable of exhibiting a reliable operation for any weather condition.

تصميم مضخمات قدرة راديوية التردد بتقنية CMOS مع محولات جامعة للقدرة == Design of RF Power Amplifiers With Power Combining Transformers

Author name: سهاد حسين جاسم
Supervisor name: احمد سعدون عز الدين
Specific topic: Electronic Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: باستخدام تقنية CMOS، تواجه تكامل مضخمات القدرة العديد من التحديات بمستوى الواط والمستخدمة لتطبيقات الاتصالات اللاسلكية. وللتغلب على هذه المحددات، يمكن استخدام عدد من الوسائل واطئة الفولتية ودمجها بكفاءة باستخدام المحولات على الرقاقة لزيادة قدرة الخرج النا | In CMOS technology, many challenges face the integrated watt level power amplifiers (PAs) used in wireless applications. Consequently, to overcome these limits, several low voltage devices should be combined efficiently with on - chip transformers in order to increase the resulting output power. In this work, two high - performance Radio - Frequency (RF) power amplifiers for watt level applications are designed and simulated in deep submicron (0.13 µm) CMOS process technology using “Agilent Advanced Design System ADS 2011.10 with “BSIM4” as a simulation module for Metal - Oxide - Semiconductor Field - Effect Transistor (MOSFET) devices. The design includes a comparison for the conventional transformer combining techniques SCT, PCT and the hybrid type PSCT. The amplifiers incorporate a parallel combination of four differential PA cores to generate high output power with good efficiency and linearity. The first part of the work presents a design for a watt - level class - AB power amplifier based on transformer type power combiner PSCT for WLAN applications. The PA delivers an Output Power (Pout) of 30 dBm, Power Gain (Gp) of 30 dB and 40% Power Added Efficiency (PAE) under 2.5 V supply. In the second part of the work, a class - E PA based on transformer type power combiner PSCT is designed. The power amplifier provides an output power of 30 dBm, power gain of 30 dB, and 54% PAE at 2.45 GHz under 1.6 V supply. Finally, in the third part of this work, an on - chip output transformer layout for the proposed power amplifiers is designed and simulated with momentum RF EM simulator of ADS 2011.10 in order to realize a fully integrated power amplifier. The simulated efficiency of the PSCT was 78% with minimum insertion losses (ILmin) 0.87 dB.

تصميم متحكم ذكي لنظام تتبع شمسي بالاعتماد على مصفوفة البوابات الرقمية القابلة للبرمجة == Design of Intelligent Controller For Solar Tracking System Based On FPGA

Author name: ياسر محمد عبد
Supervisor name: حنان عبد الرضا عكار
Specific topic: Electronic Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: ان الحاجة لزيادة توليد الطاقة الكهربائية جعل استخدام الخلايا الشمسية تلعب دورا هاما في الحياة اليومية، وعليه من المهم استخدام نظام يسمح بتتبع الخلايا الشمسية لضوء الشمس لزيادة او الحصول على القيمة المثلى للطاقة الكهربائية من الخلايا الشمسية. تم في هذا ا | The need to increase the energy generation makes the use of solar cells plays an important role in the daily life. For this reason, it is important to use solar tracking system to increase or getting almost optimum value from solar cells. In this thesis, solar cells model was implemented using MATLAB to show the characteristics of any solar cell depending on data sheet. Intelligent controllers was designed and used to make solar cells facing the sun all days. The proposed controller was trained by two ways; the first was trained by supervised feed forward neural network and the second by Particle Swarm Optimization (PSO) and then comparing the results obtained. The controller was trained using MATLAB and the converting it to simulink model in order to test it, and converts, it to a Very high speed integrated circuit Hardware Description Language (VHDL) language using MATLAB tool box in order to download it on Spartan 3A Field Programmable Gate Arrays (FPGAs) card. This makes the implementation of the intelligent controller more efficient and easy to use because of its reprogram - ability and the high speed performance. The controller was designed to a fully controlled DC motor driver which is used to rotate two DC motors in X - axis and Y - axis directions respectively.The experimental results show that tracking sun increases the efficiency of the system to produce energy from solar cell about 44.3778 % more energy than the solar cell without tracking system.

الغاء تداخل المسا ارت التخميني في انظمة الوصول المتعدد باستخدام تقسيم الترميز الواسع الطيف لشبكات الاتصال اللاسلكية == Multipath Interference Cancellation Investigation In Wcdma Communication Networks

Author name: نور محمد خليل
Supervisor name: منال جميل الكندي
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: Bit Error Rate (BER) and Bit Energy to Noise Ratio(?????????) performance of the 1 - D RAKE receiver without , with Space Time Transmit Diversity (STTD) and 2 - D RAKE without , with (STTD) and also without and with beamforming for WCDMA over RayleighChannel in presence of Additive White Gaussian Noise (AWGN) channel is demonstrated with purpose of making simulation of m - files developed in Matlab.Results are evaluated in terms of BER and ????????? considering the number of Base Station (BS) transmit antennas (1 - D RAKE and 2 - D RAKE receivers), and the number of RAKE fingers (1 - D RAKE receiver) and the number of Mobile Station (MS) receive antennas (2 - DRAKE receiver). The performance results of 1 - D RAKE and 2 - D RAKE receivers showed that the receivers have satisfactory BER performance and the performance of RAKE receivers is more improved by increasing the number of RAKE fingers, performance is even better when beamforming was applied.The performance results of the three receive diversity of 2 - D RAKE receiver schemes : Selection Combining (SC), Equal Gain Combining (EGC) or Maximal Ratio Combining (MRC)) of 2 - D RAKE showed that there are significant improvements in BER and ?????????performance over the 1 - D RAKE. BER of 10???? can be obtained at ????????? ? 5 dB performance with four fingers of 2 - D RAKE receiver with STTD and beamforming and MRC scheme for five receive antenna elements.

تحسين جودة الصورة التوموغرافية المعاد تركيبها باستخدام خوارزمية التسقيط العكسي المرشحة == Enhancement of Tomographic Image Quality Reconstructed By Filter Backprojection Technique

Author name: دعاء نوفل حازم
Supervisor name: محمد حسين الحياني
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: Computed tomography refers to the imaging of slices of an object by exposing them to X - ray in different directions. Measurement of image quality is one of great importance in the field of medical applications. In applications such as CT and MRI scanning, most of the time the quality of reconstructed image is assessed qualitatively by radiologist or domain experts which are purely subjective evaluation.The FBP algorithm produces excellent quality and high performance reconstruction compared with other reconstruction algorithms. This thesis presents different projection types (fan beam geometry, and cone beam geometry) for the image reconstruction, the geometries are calculated analytically by specified 2D head phantom for fan beam and 3D head phantom for single slice spiral cone beam geometry with different ranges covering angle.In the thesis the FBP algorithm was applied with the fan beam and single slice geometries. Different types of filters (Hann, Hamming, Kaiser, Cosine, Ram - Lak, and Gaussian) are used in the algorithm and a new window filter is proposed in the algorithm. Comparisons are made between the new window and different common windows by quality measurement to get a reconstructed image with high quality and high performance suitable for the implementation of the FBP.A computer programs has been designed, written, and implemented in this work using MATLAB 7.1, for fan beam and single slice projections. Good results of quality and performance were obtained for the tomographic reconstructed image from its projection on CT scanner.

تقنيات النمذجة الذكية في تنبوء حمل الطاقة الكهربائية == Intelligent Modeling Techniques of Electric Power Load Forecasting

Author name: يونس محي نصيف
Supervisor name: حنان ميخائيل داود
Specific topic: Electrical Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: As far as electrical power system is concerned, there has been a need to find out the future load in advance. Load forecasting has played an important role in the generation, transmission and distribution system planning. Load forecasting of future load demand is significant for an economic and secured operation of power systems. In general, the objective of high - precision load forecasting is difficult to achieve due to complex effects on load by a variety of factors.This thesis focuses on the study of long term load forecasting by using multiple linear regression (MLR) method and using different types of computational intelligence methods such as feed forward Neural Network with back - propagation (BP) tuning algorithm (FNN - BP), feed forward Neural Network with particle swarm optimization (PSO) tuning algorithm (FNN - PSO) and Elman Neural Network with back - propagation (BP) tuning algorithm (ENN - BP). Such forecasts will be highly useful in proper system planning and operations. The algorithms have been demonstrated using simulation programs in MATLAB environment.The usefulness of the five forecasting techniques was tested on a test system data for a Big Utility Company (Egyptian Unified Network). The obtained results showed that the ENN - PSO method takes advantage of accuracy and efficiency in prediction.The ENN - PSO method was performed using population growth data on the Iraqi National Grid for the duration from 2014 to 2030.

النظام المضبب للتحكم بمشكلة التزاحم لبروتوكول (التحكم في الارسال) في الشبكات المختلطة == A Fuzzy Based TCP Congestion Control For Hybrid Networks

Author name: سارة رعد قاسم
Supervisor name: زينب توفيق باقر
Specific topic: Electrical Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: Transmission Control Protocol (TCP) is designed to deliver seamless and reliable end - to - end data transfer across unreliable networks and is offered connection - oriented, byte - stream service. The Internet’s TCP is probably the most widely used protocol; it is also the most carefully tuned since performance of Internet is largely based on TCP. However, throughput in TCP degrades notably when operated in erroneous networks. In erroneous networks, TCP misinterprets random packet losses and the subsequent packet reordering due to high bit error rate as congestion and invokes congestion control by triggering to fast retransmission and fast recovery, leading to under - utilization of the network resources and affecting TCP performance critically.Many proposals have been used to improve TCP performance in wireless networks. Most of these proposals were based on changing the TCP header and add more complications to the main mechanism. Means of improving performance of TCP over erroneous links were proposed using fuzzy controller in a simple manner (without changing the header) by tracking the delay and the frequencies of the occurrences of timeouts and triple duplicate acknowledgement (3dupacks) to differentiate congestion loss from bit error loss. The first proposal was FReno (Fuzzy+NewReno) but this new algorithm failed to achieve good efficiency. The second proposal was FVegas (Fuzzy+Vegas) and it also failed to improve TCP’s resource utilization. The third proposal was FWestwood (Fuzzy+Westwood) which significantly improved TCP performance. The proposed algorithm was compared against standard TCP variants for different error rates using OMNET++4 version 4.3.1 IDE simulator. FWestwood algorithm helped TCP to distinguish between congestion and packet loss and increase the performance in erroneous wired network, heterogeneous networks, wireless networks and mobile network. Results from simulations showed that in a congested network with (1% to 10%) of random packet loss rate, FWestwood achieved significant improvements in different erroneous networks over other TCP schemes. Also it achieved friendliness fair share of the link with other TCP standards.

المسار الامثل للجراحة الروبوتية الطبية باستخدام الخوارزمية الجينية == Path Optimization For Medical Surgery Robotic Using Genetic Algorithm

Author name: زهراء داود حسين
Supervisor name: مهند زيدان خليفة | ايمان صالح كريم
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: تناولت هذه الرسالة دراسة تصميم امثل لموديل مختار للانسان الالي المستخدم في مجال الجراحة البشرية (جهاز التنظير البطني الجراحي ) المستخدم في مستشفى الصدر التعليمي في محافظة ميسان والمصنع من قبل شركة (KARL STORZ) من خلال زيادة عدد درجات الحرية لتصل سبعة درج | This thesis presents a study for optimal design of a robot to be used in human surgery (Laparoscope device). It was done in Al - Sader educational hospital in Maysan Governorate. The robot was manufactured by Karl Storz company. Connecting linkages were increased to get seven degrees of freedom. It is operated by the surgeon hand (complete rotation 360o , rotation in two opposite directions perpendicular to each other ,transformation along the major axes , triple joint (pitch ,roll, and yaw). Optimization has been done to these models after making analysis to the surgical robot (forward kinematic, inverse kinematic, dynamitic analysis). The optimal design was obtained by using genetic algorithm method to choose the optimal path planning in the working area. This was with the presence of obstacles to tip of end - effector motion that exists, in mechanical arm to the new model that used in this thesis. This was done by making an integrated computer program through MATLAB (R2013a). The results of best path planning would shorten length without hitting any obstacle, assuming the surrounding environment will be variable. The position and obstacle shapes would be random. We found that the best path planning in every environment depends on maximize objective function that presented by shortest length of the path. This is important from the medical point of view. This was applied successfully in practice on an industrial robot and the resulted optimal parameters to that robot with matching of the theoretical side with practical side in robot motion. The practical side was made in laboratory of the Research Unit of Automation and Robotics in the Control and Systems Engineering Department, University of Technology. The robot used was the Lab - Volt Servo Robot System Model 5250 (RoboCIM5250). This thesis includes studying the tools used in laparoscope and focuses on recent types of graspers with parallel jaws connected to the chosen design. It was noticed that the maximum entrance force for the abdominal tracar must not exceed 5N. The force on the last point of jaws is 0.42N. It was found that this force will not cause bleeding in the tissue during procedure. And that this type of small size grasper can be bent during operation in the allowed field of workspace while maintaining good strength.

التوزيع الامثل للمتحسسات في شبكة المتحسسات اللاسلكية باستخدام خوارزمية الامثلية المستوحاة من نظرية الاسراب == Optimum Sensors Deployment In Wireless Sensor Networks Using Swarm Based Bio - Inspired Optimization Algorithms

Author name: هيثم سعدون عفتان
Supervisor name: نزار هادي عباس
Specific topic: Electrical Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: The increased demand for Wireless Sensor Networks (WSNs) in different areas of application has intensified studies dedicated to the deployment of sensor nodes in the recent past. The deployment of sensor nodes required that some of the key objectives should be satisfied, which are the coverage ratio of the monitoring area and the lifetime of the network.In this thesis, a mathematical model to optimize the coverage ratio and the lifetime of network is developed to ensure a better utility of the WSN. The model is formulated based on several parameters such as the size of the monitoring area, network models, the total number of sensor nodes, visibility requirements, sensing/communication radius, etc.Popular swarm based bio inspired algorithms have been used to optimize the WSN deployment. The coverage optimization process has been carried out by single objective optimization algorithms such as the Ant Colony Optimization (ACO) algorithm, modified version of Particle Swarm Optimization called Discrete PSO (DPSO), Discrete Artificial Bee Colony (DABC) algorithm and a new proposed algorithm called Quantum Artificial Bee Colony (QABC). QABC is based on quantum physical concepts to improve the local search capability of standard ABC algorithm. Thereafter, a multi objective optimization algorithm has been utilized to optimize the coverage ratio and lifetime of WSN. The multi objective optimization has been carried out by Non - dominated Sorting Genetic Algorithm (NSGA - II). All of these algorithms are simple, effective and computationally efficient optimization techniques.The WSN deployment has been simulated using MATLAB 7.12.0 (R2011a) package, NetBeans 7.4 Java integrated development environments, JMETAL 4.5 and Java Universal Network/Graph (JUNG 2.0.1) frameworks. The computer simulation results showed that the proposed algorithm for coverage ratio maximization was up to two times faster than the others. Furthermore, the conducted simulation indicated that the QABC algorithm offered (6%) better solution in terms of coverage in comparison with the others in some cases. Also the results showed that the deterministic deployment can achieve up to (25%) better coverage ratio than the random deployment. In addition, QABC outperformed GA, PSO and ABC algorithms when applied to several test problems. Additionally, the results showed that the NSGA - II algorithm could effectively optimize the network lifetime and coverage ratio and produced good convergent solutions to the Pareto front and was uniformly distributed along it.

نظام كشف وتمييز لوحة الرخصة للسيارات العراقية == License Plate Detection And Recognition System For Iraqi Cars

Author name: ثائر عذار هاشم
Supervisor name: اياد ابراهيم عباس
Specific topic: Electronic Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: نظام كشف وتمييز لوحات ارقام السيارات هو تقنية في معالجة الصور يستخدم للتعرف على السيارات من خلال لوحات الارقم الخاصة بها, او بكلمات اخرى هي تقنية تستخدم لتحويل نص صورة لوحة ارقام السيارات الرقمية الى ملف نص ممكن ان يحرر ويستخدم في اي برنامج او تطبيق اخر | Automatic License Plate Detection and Recognition (ALPDR) system is an image processing technology used to identify vehicles by their license plates, or in other words, is a technology used to convert the text on digital images of vehicle license plates to a text file that can be edited and used as such by any other program or application that needs it.License Plate Detection and Recognition system for Iraqi cars have a wide range of applications; it is used to extract plate number to create automated solutions for various problems. Among these applications : parking, border crossing, traffic control, access control and stolen cars tracking.This system consists of two main parts : the first is a practical implementation of how to take a picture automatically for cars passes, this was done by two sensors type (GP2Y0A21YK0F sensor) connected with each other and interfaced with a camera (A4tech USB camera), this camera is interfaced using Matlab with the PC. The camera is attached using USB port. The second part is image processing, this part includes four basic stages : The first stage is image preprocessing which involves image normalization and RGB to gray image conversion. Second stage is detection of a possible license plate using edge detection technique and extracts these LP using region growing technique, detection rates reach to 95%. Third stage is alphanumeric character segmentation to isolate each character, numbers and words of the license plate using Otsu's and Hough transforms technique for subsequent recognition. The last stage reads the alphanumeric character and words by correlation template matching, which is a simple, fast and given a recognition rate reach to 98.245%.

محاكاة تضمين تقسيم التردد المتعامد المتعدد المستخدمين المشفر في الخط النازل == Simulation of Coded Multiuser Ofdm Downlink

Author name: دﻧﻴﺎ ﻓﺆاد فاروق النعيمي
Supervisor name: رعد سامي فياض
Specific topic: Communications Engineering
Degree: Master
Language: English
University location: Baghdad
First pages:
Abstract: The orthogonal frequency division multiple access (OFDMA) scheme adopts orthogonal frequency division multiplexing (OFDM) subcarriers, which are particularly suited for transmition over broadband frequency selection channels, to support multiusers. The scheme considered usually assigns a subset of subcarriers to each user and adopted adaptive techniques for the allocation of available resources/subcarriers according to the channel state information (CSI) estimated at the transmitter using a reverse link. This thesis proposed three coded multiuser OFDM schemes based on spreading the data of each user over all subcarriers without CSI at the transmitter. The idea behind these schemes is to split the OFDM transceiver into two stages : one common to all users while the other consists of identical parallel units with each unit is used to process the data related to an individual user. The two stages are separated by a multiplexer/demultiplexer unit whose position can be chosen to yield different schemes. The three schemes considered here are : user multiplexed scheme, inner coded multiplexing scheme, and mapper multiplexing scheme. The proposed schemes implemented are using MATLAB simulink (version 7) to investigate their performance under different operating conditions related to number of users, Rayleigh fading channel, and serial concatenated codes. The results are compared with those related to two conventional schemes, subcarrier mapping scheme and outer coded multiplexing scheme. The simulation results indicate that the proposed user multiplexing scheme may offer performance as high as that offered by the conventional outer coded multiplexing scheme but with reduced number of equipments.
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