Flexible decision-aided maximum likelihood phase estimation in coherent optical phase-shift-keying systems

Xiaodi You, Jian Chen, Ping Wang, Changyuan Yu, Pengfei Li

Research output: Journal article publicationJournal articleAcademic researchpeer-review

3 Citations (Scopus)

Abstract

ÂDecision-aided maximum likelihood (DA-ML) phase estimation has been applied in coherent optical communication systems due to its high computational efficiency. However, conventional DA-ML scheme only assumes constant phase noise within each observation block, thus causing block length effect (BLE) which degrades system performance. In this paper, we take into account the time-varying laser phase noise and propose a flexible DA-ML phase estimation method for carrier phase recovery in coherent optical phase-shift-keying systems so as to eliminate BLE. Weighted coefficients based on ML criterion are introduced to strengthen the estimation accuracy. The statistical property of phase estimation error is derived, and the bit error rate (BER) performance is also evaluated. Numerical simulation results show that our flexible DA-ML scheme is very robust against time-varying phase noise. Compared with conventional DA-ML receiver, it can significantly reduce the phase estimation variance, improve the BER performance and increase the laser linewidth tolerance. By adopting the flexible DA-ML method with a relatively larger block length, BLE can be effectively eliminated. Thus, the BER performance can be significantly improved without carefully finding out the optimum block length or the optimum forgotten factor.
Original languageEnglish
Pages (from-to)204-212
Number of pages9
JournalPhotonic Network Communications
Volume32
Issue number2
DOIs
Publication statusPublished - 1 Oct 2016
Externally publishedYes

Keywords

  • Block length effect (BLE)
  • Coherent optical communication
  • Decision-aided maximum likelihood (DA-ML)
  • Phase estimation
  • Weighted coefficients

ASJC Scopus subject areas

  • Software
  • Atomic and Molecular Physics, and Optics
  • Hardware and Architecture
  • Computer Networks and Communications
  • Electrical and Electronic Engineering

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