Sequential Number-Theoretic Optimization for High-Dimensional Channel Equalization in Coherent Optical Communication Systems

In this paper, we propose to jointly estimate channel distortions including the transmitter and receiver in- phase/quadrature (IQ) mismatch, frequency offset (FO) and phase noise (PN) by sequential number-theoretic optimization (SNTO) in coherent optical communication systems. A decision-feedback signal detection scheme is subsequently proposed after the joint estimation, which guarantees real-time estimation of the PN. The feasibility, accuracy and robustness of the proposed SNTO-based algorithm are verified via simulations.