Reducing peak-to-average power ratio (PAPR) using partial transmit sequence in OFDM systems

OFDM is a multicarrier system supporting high data rate transmission and generally requires no equalization at the receiver, making it simple and efficient. However, a drawback of this system is the large peak-to-average-power ratio (PAPR) of the transmit signal, which makes its straightforward implementation quite costly. There are several techniques to attack this problem, but most of them are suited for specific applications or small numbers of subcarriers. Selected mapping (SLM) is one of these; however, this method becomes inefficient, if the number of subcarriers or the vector-size is large. The partial transmit sequence (PTS) method was proposed as an improved strategy to tackle the problem. In this work, four variants of PTS, in terms of subblock partitioning, are discussed and the results of the implementations are presented.

1. Introduction

Orthogonal Frequency Division Multiplexing (OFDM) is one of the MultiCarrier Modulation (MCM) techniques that have now gain importance as an alternative for wireless communication. When applied in a wireless environment such as radio broadcasting, it is usually referred to as OFDM. However in a wired environment, such asin Asymmetric Digital Subscriber Lines (ADSL), the term Discrete Multilane (DMT) is more appropriate.