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.