Xiugang Wu (Stanford)
Feb 22, 2016.
Title and Abstract
Improving on the Cut-Set Bound via Geometric Analysis of Typical Sets
Our approach for developing the new bound significantly deviates from the standard information-theoretic approach for proving upper bounds on the capacity of multi-user channels. We build on measure concentration to analyze the geometric probabilistic relations between the typical sets of the n-letter random variables associated with a reliable code for communicating over the channel. These relations translate to new entropy inequalities between the n-letter random variables involved. Our approach can be extended to the discrete memoryless relay channel, and in particular, can be used to obtain surprising insights on a long-standing open problem posed by (Cover, 1987), namely, what is the minimum required relay-to-destination communication rate in order for the capacity of the relay channel to be equal to that of the broadcast cut.
Xiugang Wu is a postdoctoral fellow in the Department of Electrical Engineering at Stanford University. He received the B.Eng. degree in electronics and information engineering from Tongji University, Shanghai, China, in 2007, and the M.A.Sc. and Ph.D. degrees in electrical and computer engineering from the University of Waterloo, Waterloo, Ontario, Canada, in 2009 and 2014 respectively. His research interests are in information theory and wireless networks