Parameter-adjustable piecewise exponential companding scheme for peak-to-average power ratio reduction in orthogonal frequency division multiplexing systems

High peak-to-average power ratio (PAPR) is a major drawback of orthogonal frequency division multiplexing (OFDM) systems. A new companding scheme is proposed to reduce PAPR by transforming the statistics of the companded signal into exponential distribution with adjustable parameters. The proposed scheme can enhance the bit error rate (BER) performance significantly by minimising the companding distortion in the reduction of PAPR. Moreover, with the introduction of an inflexion point and transform parameters, the proposed scheme can offer more flexibility in the PAPR reduction, and therefore achieves a better tradeoff among the PAPR reduction, BER and power spectral density (PSD) performance. With a theoretical analysis presented, the parameter selection criteria are derived. Simulation results verify that the proposed scheme can significantly improve the BER and PSD performance while reducing PAPR effectively.