A Generalization of Residual Belief Propagation for Flexible Reduced Complexity LDPC Decoding

Beside the well known iterative Belief Propagation algorithm several alternative decoding schemes for Low-Density Parity-Check (LDPC) codes providing better performance in terms of residual error rate, convergence speed or computational complexity have been developed in the last years. Recently, Informed Dynamic Scheduling has been proposed in [1] providing different decoding strategies that dynamically decide which messages are passed throughout the decoding process. It was shown that the overall convergence can be sped up considerably and also more errors can be corrected compared to other (non-dynamic) decoding strategies. However, these improvements are somehow overshadowed by a significant amount of additional computational complexity that is needed for the selection of the messages to be updated in each decoding step. We propose two novel dynamic decoding strategies that allow for a flexible adaptation of the decoder´s dynamics and reduce the additional complexity remarkably while maintaining, and in some cases even exceeding, the convergence speed and error rate performance of currently known dynamic schedules.