Adaptive Hybrid PAPR Reduction in OFDM System

Abstract

High Peak to Average Power Ratio (PAPR) is still one of the most important challenges in Orthogonal Frequency Division Multiplexing (OFDM) system. In this paper, we propose a novel scheme based on Selected Mapping (SLM) technique for PAPR reduction in OFDM system. The proposed scheme is an adaptive hybrid scheme, which is based on the SLM technique and multiple transformation techniques. In the proposed scheme, instead of using only Discrete Fourier Transform (DFT) in OFDM system, we suggest to use Discrete Sine Transform (DST) and Discrete Cosine Transform (DCT) as well to get the lowest PAPR. In addition, the multiplied phase in the SLM is adapted to reduce the PAPR to an acceptable low PAPR level. Simulation results show that the proposed scheme technique can reduce the PAPR to about 4 dB in case of 256 sub-carriers and in case of 512 sub-carriers at clipping probability of 10 -3 .