Fiber-Optic Communication via the Nonlinear Fourier Transform

Tuesday, October 4, 2016 - 4:00pm

Event Calendar Category

LIDS Seminar Series

Speaker Name

Frank Kschischang


University of Toronto

Building and Room Number



The vast majority of the world's telecommunications and Internet traffic is carried, for at least part of its journey, over a network of land-based and under-sea fiber-optic cables that span the globe.  Recent decades have witnessed steady improvements in our ability to harness the information-carrying capability of optical fibers, and continued improvements rely increasingly on ever more sophisticated coding, modulation, and signal processing techniques, which are needed to approach fundamental information-heoretic limits.  Lightwave propagation in optical fibers is well modelled by the generalized nonlinear Schrödinger (NLS) equation, a partial differential equation that describes the interplay between loss, noise, dispersion, and Kerr nonlinearity, providing a challenging, yet commercially important, channel model for communication engineers and information theorists. In this work we explore the data communications applications of the nonlinear Fourier transform, a signal analysis technique that simplifies (for the NLS in lossless and noiseless fibers) the complicated nonlinear spatio-temporal signal evolution to the action of a multiplicative "filter" in the nonlinear frequency domain.  We propose a nonlinear analogue of linear frequency-division multiplexing that, unlike many other fiber-optic transmission strategies, deals with both dispersion and nonlinearity unconditionally and without the need for dispersion or nonlinearity compensation methods.  

Joint work with Mansoor Yousefi and Siddarth Hari.


Frank R. Kschischang holds the title of Distinguished Professor of Digital Communication in the Department of Electrical and Computer Engineering at the University of Toronto, where he has been a faculty member since 1991.   While on sabbatical leave, he visited MIT, Cambridge, MA in 1997-98 and ETH, Zürich, in 2005.  While on research leave, supported by both a Killam Research Fellowship and a Hans Fischer Senior Fellowship of TUM/IAS, he visited the Technical University of Munich in 2011, and in 2012-13.  Kschischang's research interests are focused primarily on the area of channel coding techniques, applied to wireline, wireless and optical communication systems and networks.  In 1999 he was a recipient of the Ontario Premier's Excellence Research Award and in 2001 (renewed in 2008) he was awarded the Tier I Canada Research Chair in Communication Algorithms at the University of Toronto.  Jointly with Ralf Kötter he received the 2010 Communications Society and Information Theory Society Joint Paper Award.  He received the 2012 Canadian Award in Telecommunications Research.  He is a Fellow of IEEE, of the Engineering Institute of Canada, and of the Royal Society of Canada.  He has received six departmental teaching awards, the 2006 Faculty Teaching Award, and the 2010 University of Toronto Faculty Award of Excellence.