摘要
Based on the optimization and improvement for the construction method of systematically constructed Gallager (SCG) (4, k) code, a novel SCG low density parity check (SCG-LDPC)(3969, 3720) code to be suitable for optical transmission systems is constructed. The novel SCG-LDPC (6561,6240) code with code rate of 95.1% is constructed by increasing the length of SCG-LDPC (3969,3720) code, and in a way, the code rate of LDPC codes can better meet the high requirements of optical transmission systems. And then the novel concatenated code is constructed by concatenating SCG-LDPC(6561,6240) code and BCH(127,120) code with code rate of 94.5%. The simulation results and analyses show that the net coding gain (NCG) of BCH(127,120)+SCG-LDPC(6561,6240) concatenated code is respectively 2.28 dB and 0.48 dB more than those of the classic RS(255,239) code and SCG-LDPC(6561,6240) code at the bit error rate (BER) of 10 -7 .
Based on the optimization and improvement for the construction method of systematically constructed Gallager （SCG） （4, k） code, a novel SCG low density parity check （SCG-LDPC）（3969, 3720） code to be suitable for optical transmission systems is constructed. The novel SCG-LDPC （6561,6240） code with code rate of 95.1% is constructed by increasing the length of SCG-LDPC （3969,3720） code, and in a way, the code rate of LDPC codes can better meet the high requirements of optical transmission systems. And then the novel concatenated code is constructed by concatenating SCG-LDPC（6561,6240） code and BCH（127,120） code with code rate of 94.5%. The simulation results and analyses show that the net coding gain （NCG） of BCH（127,120）＋SCG-LDPC（6561,6240） concatenated code is respectively 2.28 dB and 0.48 dB more than those of the classic RS（255,239） code and SCG-LDPC（6561,6240） code at the bit error rate （BER） of 10-7.
基金
supported by the National Natural Science Foundation of China (Nos.61071117, 61275077 and 61003256)
the Natural Science Foundation of Chongqing CSTC (No.2010BB2409)
the Science and Technology Foundation of Chongqing Municipal Education Commission(No.KJ110519)
