3) Thu, 3/30/06, 10:40 am, NEB 201

Moe Z. Win:
Fundamental Limits on Wide Bandwidth Signal Acquisition (A Convexity and Optimization Perspective)

Abstract:
We propose a search technique that takes advantage of multipath, which has long been considered deleterious for efficient communication, to aid the sequence acquisition in dense multipath channels.  We consider a class of serial-search strategies and use optimization and convexity theories to determine fundamental limits of achievable mean acquisition times (MATs).  In particular, we derive closed-form expressions for both the minimum and maximum MATs and the conditions for achieving these limits.  We prove that a fixed-step serial search, a form of non-consecutive serial search, achieves the near-optimal MAT.  We also prove that the conventional serial search, in which consecutive cells are tested serially, should be avoided as it results in the maximum MAT.  Our results are valid for all signal-to-noise ratio values, regardless of the specifics of the detection layer and the fading distributions.

Biography:
Moe Win is an Associate Professor at the Laboratory for Information & Decision Systems (LIDS), Massachusetts Institute of Technology.  Prior to joining LIDS, he spent 5 years at AT&T Research Laboratories and 7 years at the Jet Propulsion Laboratory.  His main research interests are the application of mathematical and statistical theories to communication, detection, and estimation problems.  Specific current research topics include measurement and modeling of time–varying channels, design and analysis of multiple antenna systems, ultra–wide bandwidth (UWB) communications systems, optical communications systems, and space communications systems. 

Dr. Win has been involved actively in organizing and chairing a number of international conferences.  He is the current chair and past secretary (2002-2004) for the Radio Communications Committee of the IEEE Communications Society.  He currently serves as Area Editor for Modulation and Signal Design and Editor for Wideband Wireless and Diversity, both for the IEEE TRANSACTIONS ON COMMUNICATIONS.  He served as a Guest–Editor for the 2002 IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS (Special Issue on Ultra–Wideband Radio in Multiaccess Wireless Communications).  He received the IEEE Antennas and Propagation Society Sergei A. Schelkunoff Transactions Prize Paper Award in 2003.  In 2004, he received the Fulbright Fellowship, the Institute of Advanced Study Natural Sciences and Technology Fellowship, and the Presidential Early Career Award for Scientists and Engineers from the White House.  He was honored with the 2006 IEEE Eric E. Sumner Award “for pioneering contributions to ultra-wide band communications science and technology.”  Professor Win is an IEEE Distinguished Lecturer and elected Fellow of the IEEE, cited “for contributions to wideband wireless transmission.”