A decoding algorithm for low-density parity-check codes in impulse noise environment

The iterative message passing algorithm (MPA) for low-density parity-check (LDPC) codes is effective in the additive white Gaussian noise (AWGN) channels. However, the impulse interference is not negligible in many communication channels, such as power line channels, where the impulse interference greatly deteriorates the performance of MPA based on Gauss optimization. It is necessary to restudy the decoding for LDPC codes in impulse environment. We introduce symmetric alpha-stable (SalphaS) noise into a statistical model of impulse noise environment, and consider that interference in the receiver is a mixture of AWGN and SalphaS noise. Based on this noise model, we analyze the probability density function (PDF) of the mixed noise through the numerical calculation method, and propose a robust MPA (RMPA) to account for the impulse environment. The simulations show that the bit error rate (BER) performance of the proposed RMPA is robust.