Offset-QAM based coherent WDM for spectral efficiency enhancement


Optically multiplexed multi-carrier systems with channel spacing reduced to the symbol rate per carrier are highly susceptible to inter-channel crosstalk, which places stringent requirements for the specifications of system components and hinders the use of high-level formats. In this paper, we investigate the performance benefits of using offset 4-, 16-, and 64-quadrature amplitude modulation (QAM) in coherent wavelength division multiplexing (CoWDM). We compare this system with recently reported Nyquist WDM and no-guard-interval optical coherent orthogonal frequency division multiplexing, and show that the presented system greatly relaxes the requirements for device specifications and enhances the spectral efficiency by enabling the use of high-level QAM. The achieved performance can approach the theoretical limits using practical components.

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Additional Information: © 2011 OSA This paper was published in Optics Express and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.
Uncontrolled Keywords: Atomic and Molecular Physics, and Optics
Publication ISSN: 1094-4087
Last Modified: 20 May 2024 07:10
Date Deposited: 07 Jan 2013 10:03
Full Text Link: http://www.opti ... =oe-19-15-14617
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2011-07-18
Authors: Zhao, Jian A.
Ellis, Andrew D. (ORCID Profile 0000-0002-0417-0547)



Version: Published Version

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