Abstract:

Aiming at the convergence of the belief propagation algorithm for decoding low density parity check (LDPC) codes under SNR mismatch, an analysis method is proposed. In order to analyze the convergence of different codes, channels and SNR mismatch, the method tracks the decoding process with the extrinsic information obtained by calculating the mean and the variance using improved Gaussian approximation theory. The decoder can change the estimated precision adaptively through the result of the analysis method. The steps and the examples are also given. In the end, a flexible SNR estimation algorithm and the validity simulation are presented.