A novel construction method of QC-LDPC codes based on CRT for optical communications

• Published in: Optoelectronics letters 2016-05, Vol.12 (3), p.208-211
• Main Author: 袁建国 梁梦琪 王永 林金朝 庞宇
• Format: Article
• Language: English
• Subjects: CRT; ITU-T; Lasers; Optical Devices; Optics; Photonics; Physics; Physics and Astronomy; 代码率; 低密度奇偶校验码; 光通信; 准循环LDPC码; 构造方法; 阴极射线管
• ISSN: 1673-1905; 1993-5013
• DOI: 10.1007/s11801-016-5238-8

A novel construction method of quasi-cyclic low-density parity-check （QC-LDPC） codes is proposed based on Chi- nese remainder theory （CRT）. The method can not only increase the code length without reducing the girth, but also greatly enhance the code rate, so it is easy to construct a high-rate code. The simulation results show that at the bit error rate （BER） of 10-7, the net coding gain （NCG） of the regular QC-LDPC（4 851, 4 546） code is respectively 2.06 dB, 1.36 dB, 0.53 dB and 0.31 dB more than those of the classic RS（255, 239） code in ITU-T G975, the LDPC（32 640, 30 592） code in ITU-T G.975.1, the QC-LDPC（3 664, 3 436） code constructed by the improved combining construction method based on CRT and the irregular QC-LDPC（3 843, 3 603） code constructed by the construction method based on the Galois field （GF（q）） multiplicative group. Furthermore, all these five codes have the same code rate of 0.937. Therefore, the regular QC-LDPC（4 851, 4 546） code constructed by the proposed construction method has excellent error-correction performance, and can be more suitable for optical transmission systems.