A Low Complexity Selected Mapping Scheme by Use of Time Domain Sequence Superposition Technique for PAPR Reduction in OFDM System

By using the time domain sequence superposition (TDSS) technique, in this paper, we propose a low complexity selected mapping (LC-SLM) scheme for the peak-to-average power ratio (PAPR) reduction of the orthogonal frequency division multiplexing (OFDM) system. Unlike the conventional selected mapping (SLM) scheme which needs several inverse fast Fourier transform (IFFT) operations for an OFDM signal, the proposed scheme requires to implement two IFFT operations only. Thus, it can remarkably reduce the computational complexity. Simulation results show that the proposed scheme can achieve similar PAPR performance as the conventional SLM scheme.

I. Introduction

Orthogonal Frequency Division Multiplexing (OFDM) is an attractive technique for high-speed data transmission of the future wireless communications systems. However, OFDM has some drawbacks in transmission system. The main disadvantage of the OFDM system is the potentially high peak to-average-power ratio (PAPR) at the transmitter, which may result in significant inter-modulation and out-of-band radiation due to the nonlinearity of power amplifier. Thus, it is highly desirable to reduce the PAPR of an OFDM signal.