Edge-Based Based Dynamic Scheduling for Belief Belief-Propagation Propagation Decoding of LDPC and RS Codes
Abstract: This paper presents two low low-complexity edge-based based scheduling schemes, referred to as the e-Flooding Flooding and ee-Shuffled schedules, for the belief-propagation propagation (BP) decoding of low-density density parity parity-check and Reed-Solomon Solomon codes. The proposed schedules selectively update the edges of the code graph based on the run-time run reliability of variable and check nodes. Specifically, new message update is propagated exclusively along ng the unreliable edges of the code graph. This reduces the decoding complexity of BP algorithm as only a partial set of message updates is computed per decoding iteration. Besides, restricting the flow of message updates may also precludes the occurrence of some short graph cycles, which helps to preserve the BP message independence at certain variable and check nodes. Using numerical simulations, it is shown that the proposed edge-based edge schedules reduce the BP decoding complexity by more than 90% compared with the prior-art art BP schedules, while simultaneously improving the error-rate error performance, at medium medium-to-high signal-to-noise noise ratio over additive white Gaussian noise channel.