ZTE

ZTE Communications ›› 2012, Vol. 10 ›› Issue (1): 23-29.

• Special Topic • Previous Articles     Next Articles

Exploiting the Faster-Than-Nyquist Concept in Wavelength-Division Multiplexing Systems Using Duobinary Shaping

Jianqiang Li, Ekawit Tipsuwannakul, Magnus Karlsson, and Peter A. Andrekson   

  1. Photonics Laboratory, Dept. of Microtechnology and Nanoscience, Chalmers University of Technology, SE-412 96, G?teborg, Sweden
  • Received:2011-11-15 Online:2012-03-25 Published:2012-03-25
  • About author:Jianqiang Li (jqjqlee@gmail.com) received his BE and PhD degrees from Beijing University of Posts and Telecommunications in 2005 and 2009. In July 2009, he joined Fujitsu R&D Center, Beijing, where he researched digital coherent receivers for high-speed optical communication systems. Since June 2011, he has been s postdoctoral researcher at the photonics laboratory, Chalmers University of Technology, Gothenburg, Sweden. His research experience and interests include high-speed and high-spectral-efficiency optical communication systems, and microwave photonics. He has authored and co-authored one book in Chinese and over 50 journal and conference papers on optical transmission systems and microwave photonics. He is a member of IEEE.

    Ekawit Tipsuwannakul (ekawit@chalmers.se) received his BSc degree from Chulalongkorn University, Bangkok, in 2004. He received his MSc degree from the Royal Institute of Technology (KTH), Stockholm, in 2008. He is currently working toward his PhD degree at Chalmers University of Technology, G?teborg, Sweden. From 2004 to 2006, he was a test engineer at the Optical Transmitter/Receiver Manufacturing Group, Fabrinet Co. Ltd, Bangkok. In 2006, he joined Svedice/Northlight AB, Stockholm, and spent two years designing systems for high-speed optical transmitter/receiver characterizations. His research at Chalmers is in the area of high-speed optical transmission systems using multilevel modulation formats and all-optical signal processing.

    Magnus Karlsson (magnus.karlsson@chalmers.se) received his PhD in 1994, and since 2003, has been a professor of photonics at Chalmers University of Technology, Sweden. His research interests are linear and nonlinear fiber transmission effects and multilevel modulation in optical communication systems. He has authored or co-authored around 200 scientific journal and conference papers, served as guest editor for the Journal of Lightwave Technology, and is currently associate editor of Optics Express. He has served in the technical program committee for the Optical Fiber Communication Conference (OFC), and is currently active in the TPCs for the Asia Communications and Photonics Conference (ACP) and the European Conference on Optical Communications (ECOC). He is a fellow of the Optical Society of America.

    Peter Andrekson (peter.andrekson@chalmers.se) received his PhD from Chalmers University of Technology, Sweden, in 1988. After three years with AT&T Bell Laboratories, he returned to Chalmers University of Technology where he is now a full professor in the Department of Microtechnology and Nanoscience. From 200 to 2003, he was director of research at Cenix Inc. in Allentown, PA. From 2003 to 2004, he worked with the newly established Center for Optical Technologies at Lehigh University, Bethlehem, PA. His research interests optical amplifiers, nonlinear pulse propagation, all-optical functionalities, and very high capacity transmission. He is co-founder of the optical test and measurement company, Picosolve Inc., which is now part of EXFO (he is director of EXFO Sweden AB). Andrekson is a fellow of the Optical Society of America and a fellow of the IEEE. He is the author of about three hundred fifty scientific publications and conference papers on optical communications, among which eighty were invited papers at leading international conferences and journals, including two tutorials at the Optical Fiber Communication Conference (OFC) in 2004 and 2011. He is an elected member of the Board of Governors for the IEEE Photonics Society and has served on several technical program committees, including those for OFC and ECOC. He is an international project and candidate evaluator, and has twice served as an expert for the evaluation of the Nobel Prize in Physics. From 2003-2007, he was an associate editor for IEEE Photonics Technology Letter. In 1993 he was awarded a prize from the Swedish government research committee for outstanding work performed by young scientists. In 2000, he was awarded the Telenor Nordic research award for his contribution to optical technologies.

Exploiting the Faster-Than-Nyquist Concept in Wavelength-Division Multiplexing Systems Using Duobinary Shaping

Jianqiang Li, Ekawit Tipsuwannakul, Magnus Karlsson, and Peter A. Andrekson   

  1. Photonics Laboratory, Dept. of Microtechnology and Nanoscience, Chalmers University of Technology, SE-412 96, G?teborg, Sweden
  • 作者简介:Jianqiang Li (jqjqlee@gmail.com) received his BE and PhD degrees from Beijing University of Posts and Telecommunications in 2005 and 2009. In July 2009, he joined Fujitsu R&D Center, Beijing, where he researched digital coherent receivers for high-speed optical communication systems. Since June 2011, he has been s postdoctoral researcher at the photonics laboratory, Chalmers University of Technology, Gothenburg, Sweden. His research experience and interests include high-speed and high-spectral-efficiency optical communication systems, and microwave photonics. He has authored and co-authored one book in Chinese and over 50 journal and conference papers on optical transmission systems and microwave photonics. He is a member of IEEE.

    Ekawit Tipsuwannakul (ekawit@chalmers.se) received his BSc degree from Chulalongkorn University, Bangkok, in 2004. He received his MSc degree from the Royal Institute of Technology (KTH), Stockholm, in 2008. He is currently working toward his PhD degree at Chalmers University of Technology, G?teborg, Sweden. From 2004 to 2006, he was a test engineer at the Optical Transmitter/Receiver Manufacturing Group, Fabrinet Co. Ltd, Bangkok. In 2006, he joined Svedice/Northlight AB, Stockholm, and spent two years designing systems for high-speed optical transmitter/receiver characterizations. His research at Chalmers is in the area of high-speed optical transmission systems using multilevel modulation formats and all-optical signal processing.

    Magnus Karlsson (magnus.karlsson@chalmers.se) received his PhD in 1994, and since 2003, has been a professor of photonics at Chalmers University of Technology, Sweden. His research interests are linear and nonlinear fiber transmission effects and multilevel modulation in optical communication systems. He has authored or co-authored around 200 scientific journal and conference papers, served as guest editor for the Journal of Lightwave Technology, and is currently associate editor of Optics Express. He has served in the technical program committee for the Optical Fiber Communication Conference (OFC), and is currently active in the TPCs for the Asia Communications and Photonics Conference (ACP) and the European Conference on Optical Communications (ECOC). He is a fellow of the Optical Society of America.

    Peter Andrekson (peter.andrekson@chalmers.se) received his PhD from Chalmers University of Technology, Sweden, in 1988. After three years with AT&T Bell Laboratories, he returned to Chalmers University of Technology where he is now a full professor in the Department of Microtechnology and Nanoscience. From 200 to 2003, he was director of research at Cenix Inc. in Allentown, PA. From 2003 to 2004, he worked with the newly established Center for Optical Technologies at Lehigh University, Bethlehem, PA. His research interests optical amplifiers, nonlinear pulse propagation, all-optical functionalities, and very high capacity transmission. He is co-founder of the optical test and measurement company, Picosolve Inc., which is now part of EXFO (he is director of EXFO Sweden AB). Andrekson is a fellow of the Optical Society of America and a fellow of the IEEE. He is the author of about three hundred fifty scientific publications and conference papers on optical communications, among which eighty were invited papers at leading international conferences and journals, including two tutorials at the Optical Fiber Communication Conference (OFC) in 2004 and 2011. He is an elected member of the Board of Governors for the IEEE Photonics Society and has served on several technical program committees, including those for OFC and ECOC. He is an international project and candidate evaluator, and has twice served as an expert for the evaluation of the Nobel Prize in Physics. From 2003-2007, he was an associate editor for IEEE Photonics Technology Letter. In 1993 he was awarded a prize from the Swedish government research committee for outstanding work performed by young scientists. In 2000, he was awarded the Telenor Nordic research award for his contribution to optical technologies.

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Abstract: This paper begins with Nyquist wavelength-division multiplexing (WDM) and then introduces faster-than-Nyquist. In faster-than-Nyquist, a certain amount of inter-symbol interference (ISI) is accepted, which violates the fundamental principle of Nyquist WDM. This results in much-relaxed transceiver bandwidth and simpler spectral design. However, in faster-than-Nyquist, implementation complexity is shifted from the transmitter side to the receiver side. Therefore, successful application of faster-than-Nyquist depends on innovation in the receiver structure. In this paper, we discuss the guidelines for implementing suboptimum, low-complexity receivers based on faster-than-Nyquist. We suggest that duobinary shaping is a good technique for trading off achievable spectral efficiency, detection performance, and implementation complexity and might be preferable to Nyquist WDM. Experiments are conducted to verify robustness of the proposed technique.

Key words: coherent detection, digital signal processing, optical fiber communications, spectral-efficiency, wavelength division multiplexing

摘要： This paper begins with Nyquist wavelength-division multiplexing (WDM) and then introduces faster-than-Nyquist. In faster-than-Nyquist, a certain amount of inter-symbol interference (ISI) is accepted, which violates the fundamental principle of Nyquist WDM. This results in much-relaxed transceiver bandwidth and simpler spectral design. However, in faster-than-Nyquist, implementation complexity is shifted from the transmitter side to the receiver side. Therefore, successful application of faster-than-Nyquist depends on innovation in the receiver structure. In this paper, we discuss the guidelines for implementing suboptimum, low-complexity receivers based on faster-than-Nyquist. We suggest that duobinary shaping is a good technique for trading off achievable spectral efficiency, detection performance, and implementation complexity and might be preferable to Nyquist WDM. Experiments are conducted to verify robustness of the proposed technique.

关键词: coherent detection, digital signal processing, optical fiber communications, spectral-efficiency, wavelength division multiplexing