Scheme for High-rate LDPC Codes Based on Dual–Diagonal Matrix with Girth-6

This paper presents a novel scheme to construct a large class of high-rate low-density parity-check (LDPC) codes based on dual-diagonal matrix (DDM). After estimating the feasible sizes of the submatrices, we introduce two principles and two important parameters (interval and increment), based on which the parity-check matrices (PCMs) with 4-cycle free are constructed successfully. The designed PCMs can be used to generate high performance LDPC codes. Experiments confirm that the proposed scheme has better performance in waterfall and error floor region than the advanced LDPC coding methods. Our method can construct a large number of PCMs of similar decoding performance, which increases reliability and security during high speed communication.