Early stopping for the iterative decoding for Q-LDPC

Q-ary low-density parity-check (Q-LDPC) codes have a better performance than those of the binary low-density parity-check (B-LDPC) codes, at short and medium block lengths, but the decoder of Q-LDPC has more complexity. In this article, a new stop criterion is proposed. By analyzing the changes of the maximum posteriori probability of the variable node, the criterion decides whether the iteration of the decoder must be stopped. The simulation results show that the stop criterion can effectively reduce the computation complexity of the Q-LDPC decoder with negligible performance loss.