Non-linear companding scheme for PAPR reduction in OFDM systems

Abstract High peak-to-average power ratio (PAPR) is one of the critical drawbacks of orthogonal frequency division multiplexing (OFDM). Companding is an efficient scheme to limit the PAPR. Companding operation distorts the shape of OFDM signal, therefore reducing the PAPR with slight degradation in BER performance of OFDM signal. This paper proposes a non-linear companding transform, which transforms the ‘ α th’ power of OFDM signal magnitude into a trigonal distribution. In the proposed scheme, design parameter ‘ α ’ is used to realize a better trade-off between PAPR and BER performance. Proposed scheme provides improved spectral efficiency and BER performance with a reduction in PAPR. We have also calculated the optimal value of design parameter ‘ α ’ to achieve the optimal BER.