The study on carrier phase estimation (CPE) approaches, involving a one-tap normalized least-mean-square (NLMS) algorithm, a block-wise average algorithm, and a Viterbi-Viterbi algorithm has been carried out in the long-haul high-capacity dispersion-unmanaged coherent optical systems. The close-form expressions and analytical predictions for bit-error-rate behaviors in these CPE methods have been analyzed by considering both the laser phase noise and the equalization enhanced phase noise. It is found that the Viterbi-Viterbi algorithm outperforms the one-tap NLMS and the block-wise average algorithms for a small phase noise variance (or effective phase noise variance), while the three CPE methods converge to a similar performance for a large phase noise variance (or effective phase noise variance). In addition, the differences between the three CPE approaches become smaller for higher-level modulation formats.
@article{arxiv.1603.02106,
title = {Carrier Phase Estimation in Dispersion-Unmanaged Optical Transmission Systems},
author = {Tianhua Xu and Polina Bayvel and Tiegen Liu and Yimo Zhang and Gunnar Jacobsen and Jie Li and Sergei Popov},
journal= {arXiv preprint arXiv:1603.02106},
year = {2017}
}