Advanced Networks Colloquium: Gerhard Kramer, "A Study of the Capacity of Optical Fiber Channels"
Friday, March 25, 2016
1146 A.V. Williams Building
The Advanced Networks Colloquium
A Study of the Capacity of Optical Fiber Channels
Alexander von Humboldt Professor
Head of the Institute for Communications Engineering
Technische Universität München
Roundtable: Thursday, March 24, 11:00 a.m. – 2168 AV Williams
The capacity of optical fiber channels seems difficult to compute or even bound. Existing capacity lower bounds are based on numerical simulations using the split-step Fourier method. Representative lower bounds are reviewed. A recent capacity upper bound applies two basic tools: maximum entropy under a correlation constraint and Shannon’s entropy power inequality (EPI). The main insight is that the non-linearity that is commonly used to model waveform propagation does not change the differential entropy of a signal. As a result, the spectral efficiency of a basic fiber model is at most log(1+SNR) per mode, where SNR is the receiver signal-to-noise ratio. The results extend to other channels, including basic models of multi-mode fiber.
Gerhard Kramer is Alexander von Humboldt Professor and Head of the Institute for Communications Engineering at the Technische Universität München (TUM). He received the B.Sc. and M.Sc. degrees in electrical engineering from the University of Manitoba, Winnipeg, MB, Canada in 1991 and 1992, respectively, and the Dr. sc. techn. (Doktor der technischen Wissenschaften) degree from the ETH Zürich, Switzerland, in 1998. From 1998 to 2000, he was with Endora Tech AG, Basel, Switzerland, as a communications engineering consultant. From 2000 to 2008 he was with the Math Center, Bell Labs, Alcatel-Lucent, Murray Hill, NJ, as a Member of Technical Staff. He joined the University of Southern California (USC), Los Angeles, CA, as a Professor of Electrical Engineering in 2009. He joined TUM in 2010.
Gerhard Kramer’s research interests are primarily in information theory and communications theory, with applications to wireless, copper, and optical fiber networks. He is a Fellow of the IEEE since 2010. In 2008, he was the founding co-chair of the Annual Schools of Information Theory that today run in Australia, East Asia, Europe, India, and North America. He served as technical program co-chair of the 2008 and 2014 IEEE International Symposia of Information Theory (ISIT) and he is general co-chair of ISIT 2017. Gerhard Kramer served as the 2013 President of the IEEE Information Theory Society. He was elected a Full Member of the Bavarian Academy of Sciences and Humanities in 2015.