XPM Mitigation in WDM Systems Using Split Nonlinearity Compensation

We propose a simple method to mitigate the cross phase modulation (XPM) effect in wavelength division multiplexing (WDM) systems, which combines the split nonlinearity compensation (NLC) and the receiver-side phase recovery algorithm. In the proposed method, the split NLC can suppress the conversion from the nonlinear phase noise (NLPN) to the Gaussian-like nonlinear interference noise (NLIN), and together with the phase recovery algorithm, which can compensate for the NLPN, the impact of the XPM on the signal is finally mitigated. This method is demonstrated by a transmission simulation with 11 WDM channels and 32 Gbaud 16 QAM modulations. The simulation results show that, due to the XPM mitigation, the proposed method can provide 0.4 dB gain for 500-km transmission, 0.3 dB gain for 2000-km transmission, and about 0.2 dB gain for 3000-km to 10000-km transmissions. The influence of the transmission distance on the gain is also discussed. Moreover, the selection of the phase recovery algorithm for different transmission distances is investigated, and the results show that for a short distance the blind phase search (BPS) is better, but for a long distance the V&V algorithm is more appropriate.