Performance Research of Probabilistic Shaping Based on LDPC Coding in High Speed Optical Fiber Communication

Abstract

Because of the dispersion and nonlinear effect of the transmission medium fiber in optical communication, the power of the communication system is always limited. So this paper proposes a probabilistic shaping based on LDPC encoding technology, the optical fiber communication system of the sender to uniform distribution of 32QAM signal probability of plastic processing, make its present Gaussian distribution, the signal main energy is concentrated, circle of the zodiac, improve the inner ring constellation point fire probability, reduce the probability of outer constellation points. Secondly, LDPC code is used to correct the bits of the sender. LDPC code has great advantages in high-speed communication transmission systems, because its encoding and decoding is relatively simple, and LDPC code is close to Shannon limit. The experimental results show that PS-32QAM based on LDPC coding reduces the average transmission power and improves the transmission rate of the system in high-speed optical fiber communication system. Through experimental simulation analysis, PS-32QAM signal at the system rate of 50Gbit/s, the reception performance is good, and PS-32QAM signal compared with uniform distribution of 32QAM signal, the average power of the system transmitter is reduced by 2.164dB.