Out-of-Band Filter Compensation - GAMP Algorithm for clipped OFDM Signals

The clipping and filtering (CF) method is commonly used in orthogonal frequency division multiplexing (OFDM) systems to reduce the peak to average power ratio (PAPR). However, CF method also introduces substantial nonlinear distortion to the OFDM signal, leading to significant performance loss at receiver side. In this paper, a filter compensation-generalized approximate message passing (FC-GAMP) algorithm is proposed to mitigate performance losses caused by nonlinear distortions induced by the CF method. The algorithm incorporates a tailored design of out-of-band filtering and refines the approximate equations governing nonlinear processes by analyzing the probability distribution function post-distortion. Compared to the extant GAMP algorithms, the proposed FC-GAMP algorithm yields significant improvement in bit error rate (BER) performance under various conditions while maintaining computational efficiency comparable to traditional OFDM receivers.