Ofdm Papr Reduction By Switching Null Subcarriers Among Data-Subcarriers

Abstract

Traditional single carrier modulation techniques can achieve only limited data rates due to the restrictions imposed by the multipath effect of wireless channel and the receiver complexity. High data-rate is desirable in many recent wireless multimedia applications. However, as the data-rate in communication system increases, the symbol duration gets reduced. Therefore, the communication systems using single carrier modulation suffer from severe intersymbol interference (ISI) caused by dispersive channel impulse response, thereby needing a complex equalization mechanism. Orthogonal Frequency Division Multiplexing (OFDM) is an attractive modulation technique for transmitting large amount of digital data over radio waves. High PAPR of the transmit signal is major drawback of OFDM. Proposed method promises PAPR reduction by shifting and switching null subcarrier with data subcarrier. When it is compared with existing reduction techniques (Such as Shifting Null Subcarrier among Data Subcarrier, Interleaving Technique, PTS, SLM, Tone rejection etc), the proposed method is compatible with current commercial system. The MATLAB simulation shows a PAPR reduction of around 1.4 dB using the proposed method than the existing methods also BER performance of proposed method is much better than that of existing methods.