Low complexity carrier phase estimation for m-QAM optical communication systems

  • Yuan Li
  • Qiang Zheng
  • Yao Xie
  • Jilong Han
  • Wei LiEmail author
Original Paper


A low complexity carrier phase estimation (CPE) algorithm for M-ary quadrature amplitude modulation (m-QAM) optical communication systems is investigated in this paper. In the proposed CPE algorithm, a two-stage CPE method is adopted. In the first stage, the QPSK points of the constellation are picked out to achieve a coarse phase estimation using the traditional Viterbi and Viterbi algorithm. In the second stage, all the points of the constellation are used for a fine phase estimation. In addition, the fourth-power operation is replaced by the 4-level absolute operation for the removal of modulated data phase, which greatly reduced the complexity. The proposed method was investigated through simulation, with 16-QAM, 32-QAM and 64-QAM modulation formats, respectively. The simulation results show that the proposed algorithm has both good linewidth tolerance and amplified spontaneous emission noise tolerance as well as low complexity. Moreover, when the equalization enhanced phase noise is considered, the proposed method also has better performance than traditional algorithm.


Coherent optical communication Carrier phase estimation m-QAM 



This work was supported by Open Foundation of State Key Laboratory of Optical Communication Technologies and Networks (Wuhan Research Institute of Posts & Telecommunications), and China Southern Power Grid Projects. The authors wish to thank Dr. Shaohua Yu from Wuhan Research Institute of Posts & Telecommunications for his help.


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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  • Yuan Li
    • 1
  • Qiang Zheng
    • 2
  • Yao Xie
    • 3
  • Jilong Han
    • 2
  • Wei Li
    • 2
    Email author
  1. 1.Department of Computer ScienceCentral China Normal UniversityWuhanPeople’s Republic of China
  2. 2.Wuhan National Lab for OptoelectronicsHuazhong University of Science and TechnologyWuhanPeople’s Republic of China
  3. 3.China Southern Power GridGuangzhouPeople’s Republic of China

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