September 20, 2017
Numerical Investigation and Scaling Rules for the Estimation of Nonlinear Interference Variability of Dispersion Managed and Unmanaged Systems in Presence of PMD and Kerr Effects
We estimate the Kerr nonlinear noise variance for WDM-PDM QPSK links and its variability in presence of PMD. Results specify rules giving the PMD-based NLI statistics and its evolution with distance for both legacy and recent coherent link designs. Introduction Prediction of Quality of Transmission (QoT) has been actively investigated, encouraged by the efficiency of Gaussian Noise (GN) modeling to estimate the Kerr-induced NonLinear Interference (NLI) in the context of coherent systems 1,2 . However the variability of QoT due to the interplay between Polarization Mode Dispersion (PMD) and Kerr effects is not captured by the GN model and was shown to exceed 1.5 dB Q-factor fluctuations using Split Step Fourier Method (SSFM) 3 . Motivated by the network layer needs for the accurate knowledge of system margins and the potential reduction of excessive opto-electrical regenerations, here we further quantify the PMDKerr induced QoT variability and its evolution with distance. Our study is performed for both legacy and recent system designs, by replicating simulations in Dispersion Managed (DM) and Dispersion Unmanaged (DU) configurations, different typical PMD coefficients and considering links either based on Standard Single-Mode Fiber (SMF) or Large Effective Area Fiber (LEAF). NLI assessment method and system setup We perform simulations using Central and Graphics Processing Unit (CPU/GPU) computations to emulate the system setup shown in Fig. 1. Our investigation is made using a classical 21 channels Wavelength Division Multiplexed (WDM) Polarization Division Multiplexed Quadrature Phase Shift Keying (PDM-QPSK) system.