Reduction of PAPR of OFDM Signal by SLM and Clipping Techniques Using RS Codes

Multicarrier modulations have become broadened and Orthogonal Frequency Division Multiplexing (OFDM) has been widely implemented in high speed digital modulations. OFDM is a multicarrier transmission technique which divides the available spectrum into many carriers, each one being modulated by a low rate data stream. One major disadvantages of OFDM is that the time domain OFDM signal which is a sum of several sinusoidal leads to high peak to average power ratio (PAPR). Selected Mapping (SLM) and Clipping Technique are the promising PAPR reduction techniques for OFDM. Almost all PAPR reducing techniques degrade the BER Performance. In this paper we used SLM and Clipping techniques with Reed-Solomon Codes to improve BER. A brief comparison of performances of the system with and without the algorithm are also has been done. The code rate used is 1⁄2 and the channel considered is AWGN with QAM and BPSK.