Accurate two-stage frequency offset estimation for coherent optical systems

Dezhao Huang, Tee Hiang Cheng, Changyuan Yu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

22 Citations (Scopus)


We present a two-stage feedforward frequency offset estimation (FOE) algorithm on the basis of the phase-difference method. The first stage of the proposed FOE generates a rough FOE through averaging the phase difference between two adjacent symbols and compensates the signals. The second stage of the FOE estimates the residual FO through averaging the phase difference of two symbols with distance L , which provides a significantly larger noise-tolerance and thus improves system performance. The proposed FOE can be applied to both quadrature phase-shift keying and 16-quadrature amplitude modulation systems. Simulations show that the mean square error of the proposed FOE can be reduced through an order of two in magnitude under small laser linewidth situation compared with the classic phase-difference-based FOE. The experimental result shows that the proposed FOE gives 0.6-dB optical-signal-to-noise-ratio improvement against the classic FOE, which validates its usefulness.
Original languageEnglish
Article number6376097
Pages (from-to)179-182
Number of pages4
JournalIEEE Photonics Technology Letters
Issue number2
Publication statusPublished - 21 Jan 2013
Externally publishedYes


  • Coherent optical communication
  • digital signal processing
  • frequency offset estimation

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering

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