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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 18, Iss. 5 — Mar. 1, 2010
  • pp: 4776–4782

Equalization of nonlinear transmission impairments by maximum-likelihood-sequence estimation in digital coherent receivers

Md. Khairuzzaman, Chao Zhang, Koji Igarashi, Kazuhiro Katoh, and Kazuro Kikuchi  »View Author Affiliations

Optics Express, Vol. 18, Issue 5, pp. 4776-4782 (2010)

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We describe a successful introduction of maximum-likelihood-sequence estimation (MLSE) into digital coherent receivers together with finite-impulse response (FIR) filters in order to equalize both linear and nonlinear fiber impairments. The MLSE equalizer based on the Viterbi algorithm is implemented in the offline digital signal processing (DSP) core. We transmit 20-Gbit/s quadrature phase-shift keying (QPSK) signals through a 200-km-long standard single-mode fiber. The bit-error rate performance shows that the MLSE equalizer outperforms the conventional adaptive FIR filter, especially when nonlinear impairments are predominant.

© 2010 OSA

OCIS Codes
(060.1660) Fiber optics and optical communications : Coherent communications
(060.2330) Fiber optics and optical communications : Fiber optics communications
(060.2920) Fiber optics and optical communications : Homodyning

ToC Category:
Fiber Optics and Optical Communications

Original Manuscript: November 18, 2009
Revised Manuscript: February 18, 2010
Manuscript Accepted: February 18, 2010
Published: February 23, 2010

Md. Khairuzzaman, Chao Zhang, Koji Igarashi, Kazuhiro Katoh, and Kazuro Kikuchi, "Equalization of nonlinear transmission impairments by maximum-likelihood-sequence estimation in digital coherent receivers," Opt. Express 18, 4776-4782 (2010)

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