Reducing Peak-to-average Power Ratio in Ofdm Systems by Adaptive Dynamic Range Companding

–The high peak-to-average-power-ratio (PAPR) of OFDM systems introduces inevitable nonlinear distortion in the transmitter and reduces the performance dramatically. In this paper we propose a novel scheme to reduce the PAPR with an adaptive dynamic range companding (ADRC) technique. Based on the examination of the distribution of OFDM signal amplitude, reduction of the PAPR is achieved by using a companding transformation and changing the distribution of the amplitude. Small signals are enlarged and large signals are compressed. This scheme has adaptation to signal levels with better performance than simple clipping by jointly considering the baseband signal characteristics and the RF non-linearity.