摘要
We study the decoding performance of low-density parity-check （LDPC） code based on Watermark scheme under different percentages of water-mark bits over 100 Gb/s differential quadrature phase shift keying （DQPSK） high-speed optical communication system. We also find the optimum percentage of water-mark bits according to the performance comparison. Simulation result shows an improvement of 0.5 dB net code gain by using the optimum Watermark scheme at a post-forward error correction bit error rate （BER） of 10-9, comparing with the traditional log-likelihood ratios belief propagation decoding algorithm. Also, for the same BER, there is a decrease in the number of iterations used in LDPC decoding.
We study the decoding performance of low-density parity-check （LDPC） code based on Watermark scheme under different percentages of water-mark bits over 100 Gb/s differential quadrature phase shift keying （DQPSK） high-speed optical communication system. We also find the optimum percentage of water-mark bits according to the performance comparison. Simulation result shows an improvement of 0.5 dB net code gain by using the optimum Watermark scheme at a post-forward error correction bit error rate （BER） of 10-9, comparing with the traditional log-likelihood ratios belief propagation decoding algorithm. Also, for the same BER, there is a decrease in the number of iterations used in LDPC decoding.
基金
This work was supported by the National Natural Science Foundation of China （No. 61205065）, the Open Fund of State Key Laboratory of Advanced Optical Communication Systems and Networks （No. 2013GZKF031310）, and the National 863 Program of China （No. 2013AA013401）.
