Abstract

We propose a feed-forward frequency domain adaptive linear equalizer that can track fast state-of-polarization (SOP) transients in the fiber. In the proposed method, we rely on the pilot symbols that are inserted into the DSP frame to estimate the channel response and then compensate for it. Unlike the decision-directed least mean squares (DD-LMS) algorithm, the proposed circuit is designed in a feed-forward fashion and avoids the latencies involved in DD-LMS feedback loop in order to achieve the best possible SOP tracking capabilities. The proposed algorithm is shown to be robust against high order differential group delay (DGD) and polarization dependent loss (PDL) and offers a significant tracking improvement compared to DD-LMS.

Blind, fast and SOP independent polarization recovery for square dual polarization–MQAM formats and optical coherent receivers

Mathieu Chagnon, Mohamed Osman, Xian Xu, Qunbi Zhuge, and David V. Plant
Opt. Express 20(25) 27847-27865 (2012)

Feed-forward frequency offset estimation for 32-QAM optical coherent detection

Fei Xiao, Jianing Lu, Songnian Fu, Chenhui Xie, Ming Tang, Jinwen Tian, and Deming Liu
Opt. Express 25(8) 8828-8839 (2017)

Window-split structured frequency domain Kalman equalization scheme for large PMD and ultra-fast RSOP in an optical coherent PDM-QPSK system

Zibo Zheng, Nan Cui, Hengying Xu, Xiaoguang Zhang, Wenbo Zhang, Lixia Xi, Yuanyuan Fang, and Liangchuan Li
Opt. Express 26(6) 7211-7226 (2018)

Performance of momentum-based frequency-domain MIMO equalizer in the presence of feedback delay

Wenting Yi, Eric Sillekens, Domaniç Lavery, Hubert Dzieciol, Sujie Zhou, Kevin Law, Jack Chen, Polina Bayvel, and Robert I. Killey
Opt. Express 28(13) 19133-19143 (2020)

Joint tracking and equalization scheme for multi-polarization effects in coherent optical communication systems

Yiqiao Feng, Linqian Li, Jiachuan Lin, Hengying Xu, Wenbo Zhang, Xianfeng Tang, Lixia Xi, and Xiaoguang Zhang
Opt. Express 24(22) 25491-25501 (2016)