A Novel Edge Connection Optimizing Scheme for DP-LDPC Codes

The joint source-channel coding (JSCC) scheme consisted of double protograph low-density parity-check (DP-LDPC) codes and was optimized in recent years, but there is still a lack of effective optimization algorithms for the edge connection matrix B
L2
. In this paper, through the analysis of adding edge connections at different positions of the edge connection matrix in B
L2
and calculating the decoding threshold, it is concluded that adding edge connections will not necessarily improve the waterfall and the error floor of the JSCC scheme. Since the system performance improvement by adding edge connections in B
L2
is limited, a novel efficient algorithm with minimum cost is proposed based on a differential evolutionary algorithm. Simulation results and joint protograph extrinsic information transfer (JPEXIT) calculated value have shown that the performance of the algorithm is effectively optimized for the edge connections in B
L2
.