Noise Equalization of Nonlinear Frequency Division Multiplexing Wavelength Division Multiplexing System Based on Probabilistic Shaping

A noise equalization scheme with probabilistic shaping (PS) at the transmitter side is proposed for amplified spontaneous emission (ASE) noise, nonlinear Fourier transform (NFT) processing noise, and phase noise in nonlinear frequency division multiplexing wavelength division multiplexing (NFDM-WDM) systems. The effectiveness of the scheme is verified by building a 5-channel PS-NFDM-WDM simulation system. For the transmission scenarios with ASE noise figure of 4, 5 and 6, the proposed scheme can realize performance improvements of 0.28 dB, 0.31 dB and 0.41 dB, respectively, while for the processing noise, this scheme can achieve a maximum performance gain of 0.23 dB with different launch power. The phase noise caused by different linewidths of the laser can be effectively compensated by our PS scheme, and a maximum equalization gain of 0.42 dB can be achieved.