In real-time voice and high-speed data applications,  limited delay is a key design constraint; indeed,  packet sizes as short as a few hundred bits are common in wireless systems. Traditional results on the fundamental limits of data compression and data transmission through noisy channels apply to the asymptotic regime as delay (or blocklength) goes to infinity. In this talk, I review our recent progress on the analysis of the fundamental limits as a function of blocklength. Going beyond traditional refinements to the fundamental asymptotic information theoretic limits, we investigate the backoff from capacity (in channel coding) and the overhead over entropy (in lossless compression) and the rate-distortion function (in lossy source coding) incurred by coding at a given blocklength.

Requiring new proof techniques transcending traditional ones, our approach has dual components:  computable upper/lower bounds  tight enough to reduce the uncertainty on the non-asymptotic fundamental limit to a level that is negligible compared to the gap to  the long-blocklength asymptotics; and analytical approximations to the bounds that are accurate even for short blocklengths.

Speaker's Bio :

Sergio Verdú has been on the Faculty of Princeton University since 1984. He teaches and conducts research in the School of Engineering and Applied Science where he is the Eugene Higgins Professor of Electrical Engineering. A member of the Information Sciences and Systems group and the Program in Applied and Computational Mathematics, his research interests are in Information Theory, Data Compression and Transmission.

Sergio Verdú was elected Fellow of the IEEE in 1992 and member of the U. S. National Academy of Engineering in 2007. He received the 2000 Frederick E. Terman Award from the American Society for Engineering Education, and the IEEE Third Millennium Medal in 2000. In 2005, he received a Doctorate Honoris Causa from the Polytechnic University of Catalonia. He is the recipient of the 2007 Claude E. Shannon Award, and the 2008 IEEE Richard W. Hamming Medal.

In 1998, Cambridge University Press published his book “Multiuser Detection.” His papers have received several awards: the 1992 IEEE Donald Fink Paper Award, the 1998 Information Theory Outstanding Paper Award, a IEEE Information Theory Golden Jubilee Paper Award, the 2000 Paper Award from the Japan Telecommunications Advancement Foundation, the 2002 Leonard G. Abraham Prize Award in the field of Communications Systems, the 2007 IEEE Joint Communications/Information Theory Paper Award, the 2009 Stephen O. Rice Prize in the Field of Communications Theory, and the EURASIP 2004-2007 Journal of Wireless Communications and Networking Best Paper Award.

Sergio Verdú served as President of the IEEE Information Theory Society in 1997. He is currently Editor-in-Chief of Foundations and Trends in Communications and Information Theory

(IEEE Information Theory Society Spain Chapter)