An modified beyond belief propagation algorithm over AWGN channel

Recently one decoding algorithm called as beyond belief propagation (BP) algorithm for LDPC Codes is derived using the knowledge of trapping set and different from standard BP algorithm, whose performance outperforms that of the latter over binary symmetric channel (BSC). However, the former is not suitable for additive white Gaussian noise (AWGN) channel. In this paper how to improve bit error rate (BER) performance of Beyond BP Algorithm is investigated over AWGN channel. It is found that this algorithm can be modified through setting appropriate penalty factor and obtains better performance than BP one over AWGN channel. The simulation results show dependently on choosing penalty factor modified Beyond BP Algorithm outperforms BP one over AWGN channel in high signal noise rate (SNR) region or almost whole SNR one and there are some differences for different code rates. Concretely, for medium or low code rate proposed algorithm can obtain more performance gain relative to high one when short frame is used.