A study on the PAR reduction by hybrid algorithm based on the PTS and SLM techniques

An application of orthogonal frequency division multiplexing (OFDM) signal for high-bit rate transmission is limited by the high peak-to-average power ration (PAR). Recently, two techniques for improving the PAR statistics of OFDM signal have been proposed: selective mapping (SLM) and partial transmit sequences (PTS) methods. However, the complexity of these two methods has limited its PAR reduction capability. In this paper we analyze the problems of the conventional SLM and PTS schemes and propose a hybrid algorithm to reduce the complexity PAR reduction system by using the SLM method and the PTS method with the different phase searching algorithms. The results obtained indicate that the complexity of the system can be significantly reduced when the PAR statistics degradation is negligible. Also, we propose a threshold control algorithm (TCA) for the further reducing processing time in the scheme. We show that the hybrid system with the TCA has an additional capability for the use of a large number of side information bits resulting in better PAR reduction even compared to the PTS and SLM.