PTS using novel constellation extension scheme for PAPR reduction of OFDM signals without side information

Abstract

High peak to average power ratio (PAPR) is a major hindrance in the performance of orthogonal frequency division multiplex (OFDM) systems. When OFDM signal with high PAPR passed through high power amplifiers (HPA), it requires a large back-off to operate in linear region, this leads to large dynamic range of HPA, such HPA are costly and complex with poor efficiency. Partial transmit sequence (PTS) is one of the most promising techniques for PAPR reduction. The major drawback of this technique is it requires exhaustive searching of all possible and allowable phase factors to find the optimal phase factor with lowest PAPR. This information is to be sent to a receiver as side information (SI) for decoding purpose. Sending SI puts additional burden on the transmission bandwidth thus reducing bandwidth efficiency. In this paper, a novel constellation extension-based PTS is proposed which uses novel octagonal geometry (OM-PTS) for mapping purpose. This scheme does not require transmission of any side information for decoding purpose at the receiver. Simulations are presented to show that the proposed scheme provides the same PAPR performance as conventional PTS but without need of SI transmission.