Non-Parametric Phase Tracking in Demodulation and Decoding of QAM Signals Affected by Phase Noise

Digital optical and radio transmission systems based on high order modulations can be severely impaired by phase noise affecting the local oscillators used for up-conversion and down-conversion. Pilot symbols can be of help in mitigating the impact of phase noise. This paper proposes a pilot-aided demodulation scheme where phase noise tracking is performed by a trellis-based algorithm. The benefits in terms of achievable information rate and bit error rate compared to adversary schemes are demonstrated by computer simulations for strong phase noise with coded 4096-QAM.