Joint channel response, phase noise estimation and decoding in time-selective flat Rayleigh fading channels

In this paper, we propose a joint channel impulse response (CIR), phase noise (PHN) estimation and decoding algorithm for time-selective flat Rayleigh fading channels. Building on the first-order autoregressive model approximation for both the time evolutions of CIR and PHN, a factor graph of the joint a posteriori probability function is constructed and the sum-product algorithm is applied to derive messages on factor graph. Implementation complexity is reduced by utilizing canonical distribution approach to approximate the messages as Gaussian and Tikhonov distributions. Simulation results show that the proposed joint estimation and decoding algorithm significantly outperforms the existing methods in fading channels impacted by PHN.