A Low Complexity PAPR Reduction Scheme without Side Information for Pilot Assisted OFDM Systems

Abstract

Selected Mapping (SLM) is a well known distortionless phase control Peak-to-Average-Power-Ratio (PAPR) reduction technique for Orthogonal Frequency Division Multiplexing (OFDM) systems. A major limitation of SLM-OFDM systems is that the receiver requires exact information of the phase set used at the transmitter. Usually side information (SI) is either transmitted explicitly at the loss of data rate or avoided using Blind SLM (BSLM) techniques at the expense of computational complexity. In the present work we investigate four SLM based PAPR reduction techniques and propose a new technique for pilot based SLM-OFDM systems which avoids the requirement of SI with low complexity. The proposed scheme involves cyclic shifting of pilots for each of the independent mapping in SLM systems. We compute a minimum distance vector at the receiver to detect the exact phase set used in the transmitter and avoid explicit transmission of SI. Bit Error Rate (BER) performance of the proposed scheme is evaluated in AWGN channels.