Prof. Ram Zamir (TAU)

Monday, November 7⋅15:00 – 16:00

Physical meeting (011 hall, Wolfson Building of Electrical Engineering-Kitot)

Speaker: Prof. Ram Zamir, Department of EE- Systems, Tel Aviv University

Title: Over-complete Bases for Analog Coding 

Abstract:
Over-complete bases (frames) play the role of analog codes for compression (compressed sensing) and redundant signaling (erasure correction). Applications include CDMA communications, multiple descriptions, coding for unreliable distributed computation, and more. The spectrum (eigenvalue distribution) of a subset of the frame vectors determines the code performance in the presence of noisy observations. In contrast to earlier worst-case analysis of frames, we take an "information-theoretic" approach. For the highly symmetric class of equiangular tight frames (ETF), we show that if we keep the frame aspect ratio Gamma and the frame-vector selection probability P fixed, then the spectrum converges asymptotically to the MANOVA(Gamma,P) distribution known from random matrix theory. The MANOVA distribution is strictly better than the Marcenko-Pastur spectrum associated with random (i.i.d.) frames, for common performance measures (such as noise enhancement, Shannon capacity, and the statistical restricted-isometry property). In fact, we give indications that MANOVA is the best possible subframe spectrum with respect to all (deterministic or random) frames. It follows that ETFs are the most robust analog codes for a variety of applications.

Joint work with Marina Haikin and Matan Gavish

Bio:
Ram Zamir was born in Ramat-Gan, Israel in 1961. He received his B.Sc., M.Sc. (summa cum laude) and D.Sc. (with distinction) degrees from Tel-Aviv University, Israel, in 1983, 1991, and 1994, respectively, all in electrical engineering. In the years 1994 - 1996 he spent a post-doctoral period at Cornell University, Ithaca, NY, and at the University of California, Santa Barbara. In 2002 he spent a Sabbatical year at MIT, and in 2008 and 2009 short Sabbaticals at ETH and MIT. Since 1996 he has been with the department of Elect. Eng. - Systems at Tel Aviv University. Currently he is heading the School of Electrical Engineering.

Ram Zamir has been consulting in the areas of radar and communications (DSL and WiFi), where he was involved with companies like Orckit and Actelis. During the period 2005-2014 he was the Chief Scientist of Celeno Communications. He has been teaching information theory, data compression, random processes, communications systems and communications circuits at Tel Aviv University.
He is an IEEE fellow since 2010. He served as an Associate Editor for Source Coding in the IEEE transactions on Information Theory (2001-2003), headed the Information Theory Chapter of the Israeli IEEE society (2000-2005), was a member of the BOG of the society
(2013-2015), and he organized the information theory workshop ITW 2015 in Jerusalem. His research interests include information theory (in particular: lattice codes for multi-terminal problems), source coding, communications and statistical signal processing. His book "Lattice coding for signals and networks" was published in Cambridge University Press in 2014.