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Peak to Average Power Ratio Reduction of OFDM Signals Using Clipping and Iterative Processing Methods
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One of the serious problems in any wireless communication system using multi carrier modulation technique like Orthogonal Frequency Division Multiplexing (OFDM) is its Peak to Average Power Ratio (PAPR).It limits the transmission power due to the limitation of dynamic range of Analog to Digital Converter and Digital to Analog Converter (ADC/DAC) and power amplifiers at the transmitter, which in turn sets the limit over maximum achievable rate.

        This issue is especially important for mobile terminals to sustain longer battery life time. Therefore reducing PAPR can be regarded as an important issue to realize efficient and affordable mobile communication services.

        This paper presents an efficient PAPR reduction method for OFDM signal. This method is based on clipping and iterative processing. Iterative processing is performed to limit PAPR in time domain but the subtraction process of the peak that over PAPR threshold with the original signal is done in frequency domain, not in time like usual clipping technique. The results of this method is capable of reducing the PAPR significantly with minimum bit error rate (BER) degradation.

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Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
PAPR Reduction of OFDM Signals Using Clipping and Coding
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The problem of the high peak to average ratio (PAPR) in OFDM signals is investigated with a brief presentation of the various methods used to reduce the PAPR with special attention to the clipping method. An alternative approach of clipping is presented, where the clipping is performed right after the IFFT stage unlike the conventional clipping that is performed in the power amplifier stage, which causes undesirable out of signal band spectral growth. In the proposed method, there is clipping of samples not clipping of wave, therefore, the spectral distortion is avoided. Coding is required to correct the errors introduced by the clipping and the overall system is tested for two types of modulations, the QPSK as a constant amplitude modul

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Publication Date
Tue Dec 31 2013
Journal Name
Al-khwarizmi Engineering Journal
The Power Enhancement of a Mini-Gas Turbine by Adding Ethanol to the Compressor Inlet Air
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An experimental study is conducted on the utilization of the inlet ethanol injection technique in order to evaluate its impact on the performance of a two-shaft T200D mini-gas turbine engine. The maximum degradation recorded in power output was 32.8% at the climate temperature of 45oC. Nevertheless, at that temperature, adding ethanol with Eth/LPG ratio of 20% by volume brought an enhancement in power output of 19.2% compared to normal LPG run. SFC of the dual-fuel engine ranked a level of 22% higher than that with pure LPG consumption. The overall efficiency suffered a maximum reduction of 14.4% with Eth/LPG fuel ratio of 20%, but when the loading was raised beyond 70% of the engine full load; the efficiency of dual-fuel engi

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Publication Date
Fri Jan 01 2016
Journal Name
Proceedings Of The Eleventh International Network Conference (inc 2016)
A review on power consumption reduction techniques on OFDM
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Publication Date
Thu Oct 31 2013
Journal Name
Al-khwarizmi Engineering Journal
Enhancement of a Power System Transient Stability Using Static Synchronous Series Compensator SSSC
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Static Synchronous Series Compensator (SSSC) is a well known device for effectively regulating the active power flow in a power system. In this paper, the SSSC linearized power flow equations are incorporated into Newton-Raphson algorithm in a MATLAB written program to investigate the control of active poweer flow and the transient stability of a five bus and a thirty bus IEEE test systems, during abnormal conduction (three phase fault near buses). A comparison of the results obtained for the base case without SSSC and with it to investigate the effectiveness of the device on both of the active power flow and the transient stability.

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Publication Date
Sun Dec 03 2017
Journal Name
Al-khwarizmi Engineering Journal
A theoretical study for increasing production of electric power from Iraqi steam power plants.
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This article conclude a theoretical study for the possibility to produce additional electric power from Iraqi steam power plants by  cutting – off high-pressure feed water heaters .  Three separated steam power plants which Dura , south –Baghdad and Nasria were studied . The investigation showed the possibity of increasing the electric power from 10 to 15% for Dura and Nasria , whereas 6% for south – Baghdad . According to the nowadays of operation to Iraqi steam power plants , the results showed that by cutting–off high  pressure feed water heaters we can generate additional electric power about 250 MW during 3-4 hrs. daily. In addition, the fuel consumption can be reduced in comparison with diesel generat

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Publication Date
Tue Dec 13 2005
Journal Name
Iraqi Journal Of Laser
Clinical Observation and Performance of High Power Diode Laser in the Treatment of Oral Lesions
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In this work, oral lesions belong to 17 patients, 7 males and 10 females. Their ages range between 15 and 45 years. Follow up was conducted after one day, 7 days, 14 days, one month, and finally 3 months postoperatively. The study lasted for 1.5 year. Surgical diode laser with wavelength of 810 ± 20 nm, with two power levels of 10 and 15 W were used in contact and in non-contact mode via optical fiber. The postoperative outcome revealed; greater haemostatic capability, dry, sealed wound and noticeable lack in pain sensation

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Publication Date
Mon Jan 02 2012
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Evaluation of lung ventilation in relation to the waist/hip ratio among healthy adults.
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Background: lung function is closely related to anthropometric variables. Anegative relationship between different adiposity markers and lung function has been well established.

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Publication Date
Sat Mar 01 2008
Journal Name
Al-khwarizmi Engineering Journal
Minimizing error in robot arm based on design optimization for high stiffness to weight ratio
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In this work the effect of choosing tri-circular tube section had been addressed to minimize the end effector’s error, a comparison had been made between the tri-tube section and the traditional square cross section for a robot arm, the study shows that for the same weight of square section and tri-tube section the error may be reduced by about 33%.

A program had been built up by the use of MathCAD software to calculate the minimum weight of a square section robot arm that could with stand a given pay load and gives a minimum deflection. The second part of the program makes an optimization process for the dimension of the cross section and gives the dimensions of the tri-circular tube cross section that have the same weight of

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Publication Date
Sun Apr 01 2012
Journal Name
Journal Of The Faculty Of Medicine Baghdad
The relationship of Adiponctin / Leptin ratio with metabolic syndrome
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Background: Metabolic syndrome is a cluster of risk factors for atherosclerotic cardiovascular disease caused by abdominal obesity, such as hyperglycemia, hypertension, dyslipidemia, and insulin resistance.Adiponectin is a protein hormone that modulates a number of metabolic processes, including glucose regulation and fatty acidcatabolism. Adiponectin is exclusively secreted from adipose tissue into the bloodstream. Leptin, a hormone synthesized by fat tissue had been noted to regulate energy balance and metabolism.In this study investigated the relationships of adiponectin/leptin ratio with metabolic syndrome in apparently healthy Iraqi male adults.
Objective: This study was designed to investigate the r

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Publication Date
Mon Feb 01 2021
Journal Name
International Journal Of Electrical And Computer Engineering (ijece)
OFDM PAPR reduction for image transmission using improved tone reservation
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High peak to average power ration (PAPR) in orthogonal frequency division multiplexing (OFDM) is an important problem, which increase the cost and complexity of high power amplifiers. One of the techniques used to reduce the PAPR in OFDM system is the tone reservation method (TR). In our work we propose a modified tone reservation method to decrease the PAPR with low complexity compared with the conventional TR method by process the high and low amplitudes at the same time. An image of size 128×128 is used as a source of data that transmitted using OFDM system. The proposed method decrease the PAPR by 2dB compared with conventional method with keeping the performance unchanged. The performance of the proposed method is tested with

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Scopus (6)
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