Electrical mitigation techniques for polarization mode dispersion in optical fiber systems

Electronic equalization for the mitigation of the impairments due to nonlinear and linear effects in optical fiber communication systems, including polarization mode dispersion (PMD), has become commonly used in optical fiber systems. The receiver-side equalizers applied to PMD mitigation are typically based on minimum mean-square error (MMSE) criterion and have been implemented with feedforward (FFE) and decision feedback (DFE) structures. In this paper, we use Monte Carlo method with multiple importance sampling to accurately evaluate and compare the performance of MMSE equalizers in the first-and second-order PMD plane for a realistic system dominated by ASE noise. We also discuss properties and implementation issues of the MMSE equalizers when implemented for PMD mitigation.