The Information Lost in Erasures

SPEAKER: Professor Sergio Verdu, Princeton UniversityABSTRACT: In this talk we examine the impact of erasures on the fundamental limits of lossless data compression, lossy data compression, channel coding and denoising. Particular attention is focused on the regime of sporadic erasures.We define the erasure entropy of a collection of random variables as the sum of entropies of the individual variables conditioned on all the rest. The erasure entropy rate is shown to be the minimal amount of bits per erasure required to recover the lost information in the limit of small erasure probability.When we allow recovery of the erased symbols within a prescribed degree of distortion, the fundamental tradeoff is described by the erasure rate-distortion function which we characterize. We also examine the decrease of channel capacity due to sporadic erasures. The fundamental limits when no additional encoded information is available are also studied; in this case the erased and corrupted information is reconstructed by the denoiser solely on the basis of its context.Based on joint work with Prof. Tsachy Weissman (Stanford University).Bio: Sergio Verdu is a Professor of Electrical Engineering at Princeton University. He received the Ph.D. degree in Electrical Engineering from the University of Illinois at Urbana-Champaign in 1984. His 1998 text "Multiuser Detection" earned him the 2000 Frederick E. Terman Award from the American Society for Engineering Education. Elected IEEE Fellow in 1992 for "contributions to multiuser communications and to information theory", he received the IEEE Third Millennium Medal in 2000. In 2005 he was awarded a Doctorate Honoris Causa from the Polytechnic University of Catalonia, Barcelona, Spain.He has received the 1992 IEEE D. Fink Paper Award, the 1998 Information Theory Outstanding Paper Award, a Golden Jubilee Paper Award from the IEEE Information Theory Society, the 2000 Paper Award from the Japan Telecommunications Advancement Foundation, the 2002 Leonard G. Abraham Prize Award from the IEEE Communications Society, and the 2006 Joint IEEE Communications/Information Theory Paper Award.Sergio Verdu served as President of the IEEE Information Theory Society in 1997 and is currently Editor-in-Chief of Foundations and Trends in Communications and Information Theory.Host: Prof. Giuseppe Caire, caire@usc.edu

Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248

Audiences: Everyone Is Invited

Contact: Mayumi Thrasher