A new LDPC decoding scheme for PDM-8QAM BICM coherent optical communication system

• 作 者: 刘怡 张文博 席丽霞 唐先锋 张晓光
• 机 构: State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Post
• 出 处: Optoelectronics Letters
• 发表日期: 2015年06期
• 关键词: decoding multiplexing coherent decoder quadrature parity coded iteration formula

A new log-likelihood ratio(LLR) message estimation method is proposed for polarization-division multiplexing eight quadrature amplitude modulation(PDM-8QAM) bit-interleaved coded modulation(BICM) optical communication system.The formulation of the posterior probability is theoretically analyzed,and the way to reduce the pre-decoding bit error rate(BER) of the low density parity check(LDPC) decoder for PDM-8QAM constellations is presented.Simulation results show that it outperforms the traditional scheme,i.e.,the new post-decoding BER is decreased down to 50%of that of the traditional post-decoding algorithm.

A new log-likelihood ratio (LLR) message estimation method is proposed for polarization-division multiplexing eight quadrature amplitude modulation (PDM-8QAM) bit- interleaved coded modulation (BICM) optical communication system. The formulation of the posterior probability is theoretically analyzed, and the way to reduce the pre-decoding bit error rate (BER) of the low density parity check (LDPC) decoder for PDM-8QAM constellations is presented. Simulation results show that it outperforms the traditional scheme, ie, the new post-decoding BER is decreased down to 50% of that of the traditional post-decoding algorithm.