Message passing algorithm with MAP decoding on zigzag cycles for non-binary LDPC codes

In this paper, we propose a decoding algorithm which lowers decoding erasure rates in the error floor regions for non-binary low-density parity-check codes transmitted over the binary erasure channels. This decoding algorithm is a combination with belief propagation (BP) decoding and maximum a posteriori (MAP) decoding on zigzag cycles, which cause decoding erasures in the error floor region. We show that MAP decoding on the zigzag cycles is realized by means of a message passing algorithm. A simulation result shows that the decoding erasure rates in the error floor regions by the proposed decoding algorithm are lower than those by the BP decoder.