基于等差矩阵的性质特征, 提出了一种QC-LDPC(准循环低密度奇偶校验)码的新颖构造方法。该构造方法易于有效编译码, 具有良好的围长特性, 可有效避免四环, 使生成的码字不受短环的干扰, 且在硬件实现方面可节省存储空间。仿真结果表明: 当误码率达到10-7时, 该构造方法造出的高码率QC-LDPC(3780,3542)码与ITU-T G.975中的RS(255,239)码相比, 其净编码增益提高了约2.1 dB, 具有更好的纠错性能; 与QC-LDPC(4221,3956)码相比, 净编码增益提高了0.35 dB。

On the basis of the property and features of equideviate matrixes, a novel method for constructing Quasi-Cyclic Low-Density Parity-Check (QC-LDPC) codes is presented in this paper. The LDPC codes constructed in this method are easy for effective encoding and decoding, have good girth properties and can avoid the girth-4 effectively, which prevents the generated codes from short cycle interference. Furthermore, it can save the storage space in terms of hardware implementation. The simulation results show that when the bit error rate reaches 10-7, the net coding gain of the high code-rate QC-LDPC (3780, 3542) constructed this way is improved by about 2.1 dB as compared with that of the RS (255, 239) code in ITU-T G.975, proving that the code has a better error correcting performance, and by 0.35 dB as compared with that of regular QC-LDPC (4221, 3956) code.