SLM and PTS Method with Clipping for Reducing Complexity of PAPR Reduction in OFDM

Abstract: Orthogonal frequency division multiplexing (OFDM) also referred as multicarrier communication systems, have become a key technology in current and for future communication systems. Due to OFDM’s immunity to many channel imperfections, it is the ideal modulation scheme for many applications which transmit signals in hostile envi- ronments. A major drawback of OFDM is the high peak-to-average-power ratio (PAPR) problem, which can lead to low power efficiency and nonlinear distortion at the transmitter power amplifier. Selected mapping (SLM) and Partial transmit sequences (PTS) are powerful and distortion less peak power reduction schemes for OFDM. Both reduce the PAPR by generating alternative subcarrier vector that are statistically independent OFDM symbols for a given data frame and transmitting the symbol with the lowest peak power. As we increase alternative subcarrier vector, PAPR still reduces but computational complexity also increases. In this paper the technique of clipping is used in conjunction with SLM and PTS to reduce computational complexity.

Keywords: Orthogonal frequency division multiplexing (OFDM), Peak-to-Average Power Ratio (PAPR), Clipping Ratio (CR), Selected mapping (SLM), Partial transmit sequences (PTS).