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

This paper investigates the 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 an original transmission efficiency. Simulation results show that the investigated scheme gives the PAR reduction gain of 2~3 dB compared to the original OFDM and OFDM-CDMA signals, and can provide the 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, respectively. Index Terms--OFDM-CDMA, Peak-to-Average Power Ratio (PAR), Selective Mapping (SLM), Partial Transmit Sequence (PTS).