I. Introduction
Orthogonal frequency division multiplexing (OFDM) is an attractive technology due to the immunity effect of frequency selective fading channel for high rate data transmission and it has potential applications in broadband wireless communication systems [1]. OFDM has been adopted in different application systems such as wireless LANs and digital audio/video broadcasting systems [2]. However, one main drawback is the high peak-to-average power ratio (PAPR) of OFDM transmitted signals than single carrier signal because OFDM signal in time domain is the sum of many narrowband signals [3]. Due to power amplifier nonlinearity the high PAPR can lead out-of-band radiation and inter-modulation. To face the problem, the transmission amplifier must work within its linear region to prevent the degradation of the bit error rate (BER) and spectral distortion. High linearity usually means large power dissipation and low efficiency, which is expensive for use in portable wireless applications [4].