Abstract

Electronic chromatic dispersion compensation employing maximum-likelihood sequence estimation (MLSE) has recently been the topic of extensive research and a range of commercial products. It is well known that MLSE provides a considerable benefit for amplitude modulated modulation formats such as on-off keying (OOK) and optical duobinary. However, when applied to optical phase modulation formats, such as differential phase-shift keying (DPSK) and differential quadrature phase-shift keying (DQPSK), it has been shown that the benefit is only marginal. This paper investigates joint-decision MLSE (JD-MLSE) detection applied to 10.7-Gb/s DPSK. It demonstrates that a JD-MLSE using the constructive and destructive components preserves the 3-dB optical signal-to-noise ratio (OSNR) advantage of DPSK over OOK in dispersion-limited optical systems. Furthermore, we demonstrate that the use of a shortened MZDI with MLSE for the 10.7-Gb/s DPSK modulation can equalize an accumulated chromatic dispersion of 4000 ps/nm. In addition, we discuss in this paper different MLSE schemes applied to 2$\,\times\,$10.7-Gb/s DQPSK modulation. It is shown that a joint-symbol MLSE (JS-MLSE) on the balanced outputs of the in-phase and quadrature components gives the best performance.

© 2009 IEEE

Three-chip differential phase-shift keying maximum likelihood sequence estimation for chromatic-dispersion and polarization-mode-dispersion compensation

Jian Zhao and Lian-Kuan Chen
Opt. Lett. 32(12) 1746-1748 (2007)

Maximum likelihood sequence estimation for optical complex direct modulation

Di Che, Feng Yuan, and William Shieh
Opt. Express 25(8) 8730-8738 (2017)

Chromatic dispersion and PMD mitigation at 10 Gb/s using Viterbi equalization for DPSK and DQPSK modulation formats

Wei Chen, Fred Buchali, Xingwen Yi, William Shieh, Jamie S. Evans, and Rodney S. Tucker
Opt. Express 15(9) 5271-5276 (2007)

Signal statistics and maximum likelihood sequence estimation in intensity modulated fiber optic links containing a single optical preamplifier

Nikola Alić, George C. Papen, Robert E. Saperstein, Laurence B. Milstein, and Yeshaiahu Fainman
Opt. Express 13(12) 4568-4579 (2005)

All-optical modulation format conversion from on-off-keying to multiple-level phase-shift-keying based on nonlinearity in optical fiber

Ken Mishina, Satoru Kitagawa, and Akihiro Maruta
Opt. Express 15(13) 8444-8453 (2007)