围长为8的QC-LDPC码的显式构造及其在CRT方法中的应用

Explicit construction of girth-eight QC-LDPC codes and its application in CRT method

对于任意码长PL(P≥3L2/4+L 1),利用完全确定的方式构造出一类围长为8的(4,L)QC-LDPC码。将这类码作为分量码,结合中国剩余定理(CRT)构造出一类围长至少为8且码长非常灵活的合成QC-LDPC码。在1/2码率和中等码长条件下的仿真结果表明,这种合成码在AWGN信道下具有优异的性能。

For arbitrary code lengths of the form PL（P≥3L2/4＋L？1）,a new family of（4,L）-regular quasi-cyclic（QC） low-density parity-check（LDPC） codes was proposed explicitly with girth eight.Employing the new code as a compo-nent code in the construction method of Chinese remainder theorem（CRT）,a novel class of compound QC-LDPC codes was presented with both girth at least eight and very flexible code lengths.Simulation results show that the new compound codes with rate 1/2 and moderate code lengths perform very well over the additive white Gaussian noise（AWGN） channel.