A training-based channel estimation algorithm is proposed for the faster-than-Nyquist PDM-mQAM (m = 4, 16, 64) systems with Tomlinson-Harashima precoding (THP). This is robust to the convergence failure phenomenon suffered by the existing algorithm, yet remaining format-transparent. Simulation results show that the proposed algorithm requires a reduced optical signal-to-noise ratio (OSNR) to achieve a certain bit error rate (BER) in the presence of first-order polarization mode dispersion and phase noise introduced by the laser linewidth.
@article{arxiv.1801.01433,
title = {Robust Faster-than-Nyquist PDM-mQAM Systems with Tomlinson-Harashima Precoding},
author = {Deyuan Chang and Oluyemi Omomukuyo and Xiang Lin and Shu Zhang and Octavia A. Dobre and Ramachandran Venkatesan},
journal= {arXiv preprint arXiv:1801.01433},
year = {2018}
}