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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 17, Iss. 16 — Aug. 3, 2009
  • pp: 13395–13401

MAP detection for impairment compensation in coherent WDM systems

J. Zhao and A. D. Ellis  »View Author Affiliations

Optics Express, Vol. 17, Issue 16, pp. 13395-13401 (2009)

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We propose a novel recursive-algorithm based maximum a posteriori probability (MAP) detector in spectrally-efficient coherent wavelength division multiplexing (CoWDM) systems, and investigate its performance in a 1-bit/s/Hz on-off keyed (OOK) system limited by optical-signal-to-noise ratio. The proposed method decodes each sub-channel using the signal levels not only of the particular sub-channel but also of its adjacent sub-channels, and therefore can effectively compensate deterministic inter-sub-channel crosstalk as well as inter-symbol interference arising from narrow-band filtering and chromatic dispersion (CD). Numerical simulation of a five-channel OOK-based CoWDM system with 10Gbit/s per channel using either direct or coherent detection shows that the MAP decoder can eliminate the need for phase control of each optical carrier (which is necessarily required in a conventional CoWDM system), and greatly relaxes the spectral design of the demultiplexing filter at the receiver. It also significantly improves back-to-back sensitivity and CD tolerance of the system.

© 2009 OSA

OCIS Codes
(060.2330) Fiber optics and optical communications : Fiber optics communications
(060.4080) Fiber optics and optical communications : Modulation

ToC Category:
Fiber Optics and Optical Communications

Original Manuscript: March 6, 2009
Revised Manuscript: May 27, 2009
Manuscript Accepted: June 2, 2009
Published: July 20, 2009

J. Zhao and A. D. Ellis, "MAP detection for impairment compensation in coherent WDM systems," Opt. Express 17, 13395-13401 (2009)

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  1. W. Shieh, H. Bao, and Y. Tang, “Coherent optical OFDM: theory and design,” Opt. Express 16(2), 841–859 (2008). [CrossRef] [PubMed]
  2. A. Lowery, and J. Armstrong, “Adaptation of orthogonal frequency division multiplexing to compensate impairments in optical transmission systems,” European Conference on Optical Communication, paper 4.2.1 (2008).
  3. F. C. G. Gunning, T. Healy, X. Yang, and A. D. Ellis, “0.6Tbit/s capacity and 2bit/s/Hz spectral efficiency at 42.6Gsymbol/s using a single DFB laser with NRZ coherent WDM and polarization multiplexing,” European Conference on Lasers and Electro-Optics (E-CLEO), paper C18–5-FRI (2007).
  4. F. C. G. Gunning, T. Healy, and A. D. Ellis, “Dispersion tolerance of coherent WDM,” IEEE Photon. Technol. Lett. 18(12), 1338–1340 (2006). [CrossRef]
  5. J. Zhao, and A. D. Ellis, “Performance improvement using a novel MAP detector in coherent WDM systems,” European Conference on Optical Communication (2008), paper Tu.1.D.2.
  6. J. Proakis, Digital Communication, 4th Edition, McGraw-Hill, 2001.
  7. M. Cavallari, C. R. S. Fludger, and P. J. Anslow, “Electronic signal processing for differential phase modulation formats,” in Proc. Optical Fiber Communication Conference (2004), paper TuG2.
  8. J. Zhao, L. K. Chen, and C. K. Chan, “Joint maximum likelihood sequence estimation for chromatic dispersion compensation in ASK-DPSK modulation format,” IEEE Photon. Technol. Lett. 19(1), 73–75 (2007). [CrossRef]
  9. A. D. Ellis and F. C. G. Gunning, “Spectral density enhancement using coherent WDM,” IEEE Photon. Technol. Lett. 17(2), 504–506 (2005). [CrossRef]

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