A new side-information free PTS scheme for PAPR reduction in OFDM systems

Partial transmit sequences (PTS) is an efficient technique to reduce the peak-to-average power ratio (PAPR) for orthogonal frequency division multiplexing (OFDM) systems. One main drawback of the conventional PTS method is the need of side information. When the side information is lost, the received data cannot be decoded correctly by the receiver. In this paper, we propose a new side-information free PTS scheme, where a difference vector along with an input data block is generated by using an extended constellation. After dividing the difference vector into some disjoint subblocks, the inverse fast Fourier transform of the input data block and that of each subblock of the difference vector are combined optimally to form a low-PAPR OFDM signal for transmission. Simulation results show that the proposed PTS scheme can achieve better PAPR reduction performance than the conventional PTS scheme, but it has lower computational complexity and does not need side information.

1. Introduction

Orthogonal frequency division multiplexing (OFDM) is an attractive technique for high-data-rate transmission because of its high spectral efficiency and robustness with respect to multipath fading [1]. OFDM has been widely adopted in many modern transmission systems, such as wireless local area networks (WLANs) [2], digital video broadcasting (DVB) [3], wireless metropolitan area networks (WMANs) [4], and 3GPP Long Term Evolution (LTE) systems [5]. However, OFDM systems may suffer from a high peak-to-average power ratio (PAPR) at the transmitter's output. When a high-PAPR OFDM signal passes through a nonlinear device (for example, a power amplifier), it may cause undesired in-band distortion and out-of-band radiation.