Parallel Compensation Method for Nonlinear Impairments of Optical Fiber Based on Regular Perturbation Theory

With an increase in the transmission capacity and transmission distance of optical fiber transmission systems, the nonlinear impairments in signals induced during the optical fiber transmission process have become one of the key factors in limiting the performance of optical fiber communication systems. Therefore, finding effective methods to compensate nonlinear impairments quickly and efficiently is of crucial importance for improving optical fiber communication systems. In this paper, a parallel compensation method for compensating nonlinear impairments of optical fiber based on regular perturbation theory is proposed. The proposed method is obtained by applying the regular perturbation to the nonlinear coefficient of the nonlinear Schrodinger equation (NLSE). The newly proposed simulation method and the numerical simulation method that uses the split-step Fourier method to realize digital back-propagation (DBP) use normalized square deviation (NSD) to perform quantization, achieving relatively high accuracy in low nonlinear links. In addition, the split-DBP method is used to perform signal pre-compensation at the transmitter end. When the pre-compensation ratio is 40%, the input optical power increases by 1dB and the bit error rate reduces to 32.1% as compared with the scenario of no pre-compensation. Finally, the running efficiencies of the two compensation methods are tested and compared. The result indicates that the compensation method based on regular perturbation (40 steps) is 67 times faster than the compensation method based on the split-step Fourier method (SSFM) (2 steps).