Department of Statistics, The Ohio State University
Chhotey Lal and Mohra Devi Rustagi Memorial Distinguished Lecture

Statistics in Signal Detection: The Structure of Likelihood Ratios

Dr. Thomas Kailath
Hitachi America Prof. of Electrical Engineering,
Stanford University

3:30PM - Tuesday, May 29, 2001
Room 170, Eighteenth Avenue Bldg.

Abstract

Signal Detection Theory deals with the problem of deciding from noisy observations which of a set of (deterministic or random) signals is present. As a statistics problem, this is quite straightforward: under a variety of criteria, the optimum decision rule is to compare "likelihood ratios" against suitable thresholds. However from an engineering point of view, the problem is just beginning. The issue is not so much numerical computation of the LR, but what to do with poorly specified models, how much to make intelligent approximations and simplifications, hardware implementations, etc. So engineers (and statisticians) study a variety of specific problems in order to obtain "structural information" on the form of the likelihood ratio.

We shall illustrate this process and show how fairly advanced tools from martingale theory help in this effort. Among other results, we shall encounter the important role of mean-square-error estimation in the detection problem, and surprising parallels between detection problems for random signals with "additive" Gaussian noise and with "multiplicative" Poisson-type noise.

Biography

Dr. Thomas Kailath is the Hitachi America Professor of Egineering, in the Department of Electrical Engineering, Stanford University. He is a member of the National Academy of Science, as well as the National Academy of Engineering. Prof. Kailath is a Fellow of the IEEE and the Institute of Mathematical Statistics. He is also a Past President of the IEEE Information Theory Group.

Dr. Kailath is a Co-founder, Member and ex-Chairman of the Board of Directors, Integrated Systems, Inc., which is now a publicly held company. He has received numerous best paper awards. His research intrests include Information Theory, Communication, Computation, Control, Linear Systems, Statistical Signal Processing and VLSI systems.