On Adaptive Zero Forcing for Integrated Polarization Sensing and Coherent Optical Communications

We analyze the impact of noise and polarization-dependent loss on polarization sensing with LMS equalizers, which are commonly used for optical fiber communications. For this analysis we introduce a simplified channel model, which represents the current use of the state-of-polarization (SOP) measurements for sensing with optical fiber communications equipment. The results of adaptive equalization deviate from true channel inversion, and we quantify the amount of deviation for different equalization algorithms. Potential improvements using adaptive ZF equalization are discussed, highlighting tradeoffs between channel estimation accuracy and communication performance.