Robert Calderbank
Director, AT&T Research Laboratory
Biography
Robert Calderbank is Director of the Information Sciences Research Laboratory at AT&T Labs in Florham Park, New Jersey. The Laboratory is responsible for fundamental innovation in the way AT&T uses information to operate and compete, one example being the AT&T system for International Toll Fraud Detection. It is widely known for innovation in signal processing that will enable new wireless services and speed Internet access, and for breakthrough science, like quantum computing, that is associated with the magic of discovery.
Dr. Calderbank joined AT&T Bell Laboratories in 1980 where he directed the effort that created the V.34 modem standard, and research on advanced read channel architectures that was fundamental to a highly successful strategic partnership between AT&T Microelectronics and certain disk drive manufacturers. He is one of the inventors of Space-Time codes, a breakthrough wireless technology that uses a small number of antennas to provide data rates and/or reliability far exceeding systems employed today. Dr. Calderbank's work on quantum computing with colleagues at AT&T Labs has attracted considerable coverage in the scientific and popular press.
Ingrid Daubechies
Professor, Princeton University
Biography
Ingrid Daubechies received both her Bachelor's and Ph.D. degrees (in 1975 and 1980) from the Free University in Brussels, Belgium. She held a research position at the Free University until 1987. From 1987 to 1994 she was a member of the technical staff at AT&T Bell Laboratories, during which time she took leaves to spend six months (in 1990) at the University of Michigan, and two years (1991--93) at Rutgers University. She is now at the Mathematics Department and the Program in Applied and Computational Mathematics at Princeton University. Her research interests focus on the mathematical aspects of time-frequency analysis, in particular wavelets, as well as applications.
In 1998 she was elected to be a member of the National Academy of Sciences and a Fellow of the Institute of Electrical and Electronics Engineers. The American Mathematical Society awarded her a Leroy P. Steele prize for exposition in 1994 for her book "Ten Lectures on Wavelets," as well as the 1997 Ruth Lyttle Satter Prize. From 1992 to 1997 she was a fellow of the John D. and Catherine T. MacArthur Foundation. She is a member of the American Academy of Arts and Sciences, the American Mathematical Society, the Mathematical Association of America, the Society for Industrial and Applied Mathematics, and the Institute of Electrical and Electronics Engineers.
Lecture Schedule
Tuesday, April 18, 2000 B102 Wells Hall: (Robert Calderbank)
Abstract: Quantum effects are seldom evident in today's electronic devices since the quantum states of many millions of atoms are averaged together blurring their discreteness. But in quantum computing the foundations of quantum mechanics are finding direct and visible application in information processing. The unreasonable effectiveness of quantum computing is founded on coherent quantum superposition or entanglement which allows a large number of calculations to be performed simultaneously. This coherence is lost as a quantum system interacts with its environment and an important challenge today is to devise means of preserving it.
A quantum error correcting code is a way of encoding quantum states into qubits so that error or decoherence in a small number of individual qubits has little or no effect on the encoded data. This talk will describe a beautiful group theoretic framework that simplifies the presentation of known quantum error correcting codes and greatly facilitates the construction of new examples.
This is joint work with Eric Rains, Peter Shor, and Neil Sloane.
Wednesday, April 19, 2000 B102 Wells Hall: (Robert Calderbank)
Abstract: Matrices of indeterminates with orthogonal columns appear in the mathematics literature as Orthogonal Designs. The existence of orthogonal designs is a subject that occupied Radon and Hurwitz in the 1920s. This talk describes how these designs are used to construct Space-Time Codes that dramatically improve the throughput and reliability of wireless systems employing multiple antennas at the base station and at the mobile. A Space-Time Code derived from a particular 2X2 Orthogonal Design is incorporated in the wideband CDMA standard that will support 3rd generation wireless services in the 2001-2003 timeframe. There may be as many as 1B mobile phones using this arcane mathematical structure.
Thursday, April 20, 2000 B102 Wells Hall: (Ingrid Daubechies)
Abstract: Redundant representations are often superior to bases in order to extract features, and even to denoise signals. For compression purposes, the redundancy seems a handicap, however, mostly because we don't yet know how to "quantize" these expansions effectively. (Note: quantization stands here for something very different from the transition from classical mechanics to quantum mechanics - it is, rather, the transition from coefficients that can take a continuum of values to coefficients that are restricted to a discrete ("quantized") range.)
For bandlimited signals, redundant representations have been used for a while in A/D conversion, via sigma-delta quantizers, which give an approach to quantize efficiently highly redundant samples. The talk will give an overview, from a mathamatical point of view, discuss some recent results, obtained jointly with Ron DeVore, and list open problems (of which there are many).
Friday, April 21, 2000 B102 Wells Hall: (Ingrid Daubechies)
Abstract: Because wavelets are unconditional bases for many function spaces, they give rise to good nonlinear approximation bounds. These have been viewed by mathematicians as the "explanation" of why wavelets work well for compression in a variety of settings. Yet the practice of compression is different from the question of how well we can approximate in a given basis if we are allowed to keep any N terms we choose - in practice, one has to measure the (expected) distortion as a function of the total number of bits used to convey the information. It turns out that in order to exploit the nonlienar approximation results, one has to combine them with "smart" coding strategies (invented already by the engineers!). This is joint work with Albert Cohen, Onur Guleryuz and Michael Orchard.