Shuffled belief propagation decoding

In this paper, we propose a shuffled version of the belief propagation (BP) algorithm for the decoding of low-density parity-check (LDPC) codes. We show that when the Tanner graph of the code is acyclic and connected, the proposed scheme is optimal in the sense of MAP decoding and converges faster (or at least no slower) than the standard BP algorithm. Interestingly, this new version keeps the computational advantages of the forward-backward implementations of BP decoding. Both serial and parallel implementations are considered. We show by simulation that the new schedule offers better performance/complexity trade-offs.