Research Of PAPR Reduction Schemes In Wideband OFDM System Based On Companding Transform

This paper mainly studies the Peak-to-Average Power Ratio(PAPR)reduction schemes in wireless OFDM transmission system based on the nonlinear companding transform.First of all,the paper introduces the background and significance of research on the PAPR technology,and reviews the development and evolution of related technology in domestic and foreign research field.Secondly,the basic principle of OFDM transmission system and its high PAPR problem are introduced,and the existing PAPR solutions are analyzed and evaluated deeply.Finally,in order to overcome the drawbacks of the existing nonlinear companding methods,this paper proposes four nonlinear companding schemes based on the nonlinear curve design and the optimization of signal amplitude distribution respectively.The sufficient simulation results show that the proposed schemes have a better PAPR reduction,Bit Error Rate(BER)and Power Spectral Density(PSD)performance than traditional companding schemes.Meanwhile,the proposed schemes can also maintain the average power constant.Therefore,the efficiency of the power amplifier can be improved.In addition,the proposed schemes can deliver a good trade-off between the PAPR reduction and the BER.The specific performance of the proposed schemes can be achieved by properly choosing transform parameters,to fulfill the performance requirements of various OFDM systems.