OFDM Improved Performance That Uses the Technology Selected For Mapping and an Overview of The Different Plans To Limit Paper Signals

Abstract

Orthogonal frequency division multiplexing has drawn explosive attention as a new type of high data rate transmission scheme for wireless communication system. OFDM allow the transmission of high data rates over broadband channel due to the spectral bandwidth efficiency, robustness to the multipath delay etc. However OFDM signal are very sensitive to nonlinear effects due to the high peak-to-average power radio (PAPR), which is one of the major drawback of OFDM system. which results in significant inter modulation, inter carrier interference(ICI) ,bit error rate(BER) performance degradation and undesirable out-of-band radiation when an OFDM signal passes through nonlinear devices such as high power amplifier(HPA). The complexity of analogto-digital converter (ADC) and digital-to- analog converter (DAC) also get increased if the PAPR of OFDM signal is high. Thus in OFDM system one of the important research areas is reduction of PAPR, which concern with OFDM signal performance. In this paper we describe the PAPR reduction techniques and PAPR of OFDM by using selected mapping (SLM).