학술논문
Joint Maximum Likelihood Sequence Estimation for Chromatic-Dispersion Compensation in ASK-DPSK Modulation Format
Document Type
Periodical
Author
Source
IEEE Photonics Technology Letters IEEE Photon. Technol. Lett. Photonics Technology Letters, IEEE. 19(2):73-75 Jan, 2007
Subject
Language
ISSN
1041-1135
1941-0174
1941-0174
Abstract
We determine the fundamental impairment mechanism in the chromatic-dispersion (CD)-limited hybrid amplitude shift keying (ASK)–differential phase-shift keying (DPSK) modulation format and propose the employment of joint maximum likelihood sequence estimation (J-MLSE) for CD compensation to extend the transmission reach of such format. We find that it is not the intrasubchannel interference of the ASK or DPSK subchannel but the interaction between these two subchannels that limits the transmission distance. Therefore, electronic equalization of the two subchannels separately cannot improve the overall CD tolerance of the ASK-DPSK signal. J-MLSE, however, exploits the correlation information between the detected ASK and DPSK signals and is numerically shown to improve the CD tolerance of the ASK-DPSK signal significantly.