MINI-SYMPOSIUM:

INFORMATION THEORY

Organized by the IEEE Benelux Information Theory Chapter

Date: Monday January 28, 2008

Time: 10h15-13h00

Location: TU Eindhoven, Van Trier Zaal, Traverse (Campus map)

Program

10.15 - 11.00    Prof. Emre Telatar, EPFL, "Bounds on the Capacity Region of Certain Interference Channels"

11.00 - 11.15    Break

11.15 - 12.00    Prof. Edward van der Meulen, KUL, "The Relay Channel With and Without Delay"

12.00 - 12.15    Break

12.15 - 13.00    Prof. Sergio Verdu, Princeton University, "The Information Lost in Erasures"

Abstracts:

Prof. Emre Telatar, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland, "Bounds on the Capacity Region of Certain Interference Channels."

ABSTRACT: I will describe an outer bound on the capacity region of certain interference channels and quantify the gap between it and the Han-Kobayashi inner bound. The characterization of the capacity region of certain deterministic interference channels by El Gamal and Costa follows easily from the bound, so does the "1 bit" gap for Gaussian channels of Etkin, Tse and Wang. Time permitting, I'll discuss the polyhedral structure of the Han-Kobayashi region for "cyclic" channels that permit easy generalizations of the first part. [Based on joint work (separately) with D. Tse and E. Sasoglu.]
 

Prof. Edward van der Meulen, Katholieke Univertsiteit Leuven, Leuven, Belgium, "The Relay Channel With and Without Delay"

ABSTRACT: The relay channel was introduced in 1971 and important bounds on its capacity and several capacity results were established in 1979 and following years. Since around 2000 there has been an upsurge in interest in the relay channel due to its possible usefulness in wireless communication. This has led to many new results and developments during the past few years. In this talk we revisit the classical relay channel, discuss the decode-and-forward lower bound and mention several techniques for proving this bound. We review the capacity results for some well-known cases, such the degraded and semi-deterministic relay channel, but will mention some other results as well. Then we move on to the recently introduced model of a relay-channel without delay. We will present several bounds on the capacity of this channel obtained in the recent literature. Next we return to an example of 1971 and prove that for this example the capacity without delay is strictly larger than the classical relay capacity with delay. References: van der Meulen (1971), Cover and El Gamal (1979), El Gamal and Aref (1982), Willems(1982), Kramer, Gastpar, and Gupta (2005), El Gamal and Hassanpour (2005), Willems (2006), van der Meulen and Vanroose (2007).

Prof. Sergio Verdu, Princeton University, Princeton, New Jersey, "The Information Lost in Erasures"

ABSTRACT: 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 erasures, and give general results in the sporadic erasure regime. In the case of Gaussian channels with intersymbol interference, observed through erasure channels, we obtain some new results on random matrices that enable us to find the capacity and show the optimality of waterfilling for arbitrary erasure rates. [Based on joint work with Prof. Tsachy Weissman, and on joint work with Prof. Antonia Tulino, Prof. Giuseppe Caire and Prof. Shlomo Shamai.]

MORE INFORMATION: Frans Willems, (email: f.m.j.willems@tue.nl, phone: 040-2473539).