Burst-Error-Propagation Suppression for Decision-Feedback Equalizer in Field-Trial Submarine Fiber-Optic Communications

Ji Zhou, Chengkun Yang, Dawei Wang, Qi Sui, Haide Wang, Shecheng Gao, Yuanhua Feng, Weiping Liu, Yuelin Yan, Jianping Li, Changyuan Yu, Zhaohui Li

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

In this paper, we present a field-trial C-band 72Gbit/s optical on-off keying (OOK) system over 18.8 km dispersion-uncompensated submarine optical cable in the South China Sea. Chromatic dispersion (CD) of 18.8 km submarine optical cable causes four spectral nulls on the 36 GHz bandwidth of 72Gbit/s OOK signal, which is the main obstacle for achieving an acceptable bit-error-rate (BER) performance. Decision feedback equalizer (DFE) is effective to compensate for the spectral nulls. However, DFE has a serious defect of burst-error propagation when the burst errors emerge due to the unstable submarine environment. Weighted DFE (WDFE) can be used to mitigate the burst-error propagation, but it cannot fully compensate for the spectral nulls because only a part of feedback symbols is directly decided. Fortunately, maximum likelihood sequence estimation (MLSE) can be added after the WDFE to simultaneously eliminate the residual spectral distortions and implement optimal detection. Compared to the joint DFE and MLSE algorithm, the joint WDFE and MLSE algorithm can effectively suppress the burst-error propagation to obtain a maximum 2.9 dB improvement of \boldsymbol{Q} factor and eliminate the phenomenon of BER floor. In conclusion, the joint WDFE and MLSE algorithm can solve the burst-error propagation for the field-trial fiber-optic communications.

Original languageEnglish
Article number9420243
Pages (from-to)4601-4606
Number of pages6
JournalJournal of Lightwave Technology
Volume39
Issue number14
DOIs
Publication statusPublished - 15 Jul 2021

Keywords

  • burst-error propagation
  • chromatic dispersion
  • field-trial submarine fiber-optic communications
  • Weighted decision-feedback equalizer

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this