Low-complexity par reduction schemes using SLM and PTS approaches for OFDM-CDMA signals

Abstract

The paper investigates a peak-to-average power ratio (PAR) reduction scheme employing a simple symbol transform in OFDM-CDMA systems. This approach is very simple because of no additional complexity and works without restriction on the allocation of spreading code, maintaining the original transmission efficiency. Simulation results show that the investigated scheme gives a PAR reduction gain of 2-3 dB compared to the original OFDM and OFDM-CDMA signals, and can provide further PAR reduction by combining the selective mapping (SLM) and partial transmit sequence (PTS) schemes, which are less complex compared to the ordinary SLM and PTS approaches.