Analytical Intrachannel Nonlinear Models to Predict the Nonlinear Noise Waveform

Intrachannel nonlinearity is considered as a major distortion in high capacity transmission systems. To better understand the nonlinear distortion, the nonlinearity modeling is an essential technology. Most of current nonlinear models focus on the statistical characteristics of nonlinear noise. In this paper, we investigate the analytical models that predict the time-varying nonlinear noise waveform. For the return-to-zero (RZ) pulse-shaped system, the “power weighted, additive-multiplicative model” is investigated under various system conditions for quadrature phase shift keying and 16 quadrature amplitude modulation formats, with dispersion managed and unmanaged link composed of standard single mode fiber or nonzero dispersion-shifted fiber. For the non-RZ and Nyquist pulses, the Nyquist nonlinear model is investigated. Both two models achieved 95% accuracy which is defined as the absolute value of the cross correlation between the noise waveform obtained by split step Fourier simulation and the waveform calculated by the model. Simulation also shows that the model functions well for the most optical power range of commercial communication systems.