A threshold companding scheme for reducing peak-to-average power ratio of OFDM signals

A companding technique based on threshold is proposed to reduce the PAPR of OFDM signals. In this technique, only the signals, whose amplitudes are higher than the threshold, are compressed in the transmitter. Using a simple judgment process, the expanding operation is executed to the compressed signals in the receiver. Compared with other scheme, the threshold companding scheme effectively improves the performance of PAPR by introducing a simple threshold judgment process.

I. Introduction

Orthogonal Frequency Division Multiplexing (OFDM) technology has been used in the high-rate digital communication systems because of its tolerance of multipath fading and high spectral efficiency. In Europe, OFDM has been regarded as digital modulation method in systems such as DVB-T (Digital Video Broadcasting-Terrestrial) and DAB (Digital Audio Broadcasting) standards [1]. It has also been used to physical layer in wireless LAN standards such as IEEE802.11a, 802.11g [2].