Gaussian basis expansion-based phase noise suppression for polarization division multiplexing coherent optical UFMC system

Abstract

As a form of multi-carrier modulation, universal filter multicarrier (UFMC) combined with optical communication systems provides significant advantages for long-distance transmission, including large bandwidth, low attenuation, and flexible spectrum resource allocation. While polarization division multiplexing (PDM) enhances system capacity, it concurrently introduces various interference leading to signal distortion. Notably, phase noise has a profound impact on the performance of multi-carrier modulation systems. Phase noise results in stochastic variations to the signal, making the recovery of receiver signals challenging. In this paper, we propose a phase noise suppression method based on Gaussian Basis Expansion (GBE), specifically designed for PDM coherent optical universal filter multicarrier (CO-UFMC) system. We analyze the fundamental principles of phase noise suppression using GBE and validate its effectiveness in optical UFMC transmission systems. In comparison to traditional phase noise suppression methods, our approach exhibits superior phase noise robustness, while maintaining comparable computational complexity. The GBE method significantly enhances the system’s tolerance to laser phase noise and improves its robustness against phase noise. The theoretical analysis is corroborated through numerical simulations of a 16-quadrature amplitude modulation (QAM) optical UFMC system.