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.