Certain investigations on reduction Of peak to average power ratio in OFDM systems

Abstract

Multi carrier Modulation techniques forms an integral part of any real newlinetime application which can support high speed broadband data transmission newlinebetween wireless systems In particular due to its ability to achieve high newlinespeed data transmission in frequency selective fading channels the bandwidth newlineefficient Orthogonal Frequency Division Multiplexing OFDM scheme is the newlinemajor contender for the fourth generation 4G wireless standards However newlinelarge Peak to Average Power Ratio of OFDM signals demands highly newlineexpensive High Power Amplifiers HPA with large dynamic range and this newlinestrict requirement makes the overall modulation process inefficient Hence newlinereduction of PAPR in OFDM system is of great interest for designing newlinecomputationally efficient and cost effective wireless systems this topic has newlinereceived wide attention among researchers and several solutions were newlineprovided by them newlineIn this thesis five prospective schemes for PAPR reduction in OFDM newlinesystems are introduced and their simulation results are compared with that of newlinethe conventional methods over three different communication channels newlinenamely Additive White Gaussian Noise AWGN Fading and Stanford newlineUniversity Interim 5 SUI 5 Channel Both Quadrature Phase Shift Keying newlineQPSK and 16 Quadrature Amplitude Modulation 16 QAM modulated newlineOFDM signal are considered to evaluate the proposed schemes in terms of newlinePAPR reduction and Bit Error Rate BER performance newlineThe first method is a non iterative Clipping and Filtering CF newlinealgorithm which eliminates the need for iterative filtering to reduce the noise newlineintroduced by the clipping process newline newline