A low complexity nonlinearity impairment compensation scheme assisted by label propagation algorithm

Nonlinear Impairment Compensation Using Transfer Learning-Assisted Convolutional Bidirectional Long Short-Term Memory Neural Network for Coherent Optical Communication Systems

“…Meanwhile, a balance between the performance and algorithm complexity needs to be guaranteed. The number of triplets can be determined by the range of symbol indexes m and n, so each symbol will contain N t triplets at t-th time by determining the values of m and n. According to perturbation theory, the contribution degree of triplets is mainly determined by the nonlinear perturbation coefficient C m,n in Equation (2). Figure 2a,b show the normalized perturbation coefficients C m,n for 28/85 GBaud PDM-16/64QAM after 1600/400 km transmission, respectively, and their cutoff threshold is -35 dB, namely 20 log 10 (|C m,n |/|C 0,0 |) ≥ −35.…”

“…However, the transmission capacity and distance of the current optical fiber communication system are jointly limited and constrained by both linear and nonlinear impairment of optical fiber, especially the nonlinear impairment. By increasing the input fiber power, it will cause a significant accumulation of the Kerr nonlinear effect in fiber channel, resulting in serious nonlinear phase modulation and leading to an obvious degradation in signal quality [2]. At present, the linear impairment of optical fiber can be effectively compensated, while the nonlinear impairment becomes the main obstacle for further development of optical fiber communication due to the difficulty of compensation processes [3].…”