A Physical Approach to Multiple Antenna Communication

SPEAKER: Professor Massimo Franceschetti, UC San DiegoAbstract: In multiple antenna (MIMO) systems communication is performed through the act of propagation of electromagnetic (EM) waves. EM research typically focuses on the physical aspects of propagation, while information theory (IT) focuses mainly on the communication aspects, often considering random channel models. In this talk we attempt to address the gap between these two approaches. We formally relate the concept of information transmission to the amount of diversity that EM waves can carry. Such diversity lies in two different dimensions: time and space. The classical view of Shannon's information theory considers only the time dimension along with its transformed counterpart: the frequency spectrum. However, Shannon's theory can also be applied to the space dimension which, analogous to time, becomes a capacity bearing object.The spatial information content can be quantified in a similar fashion than its temporal counterpart, by reducing the inverse problem of field reconstruction to a communication problem in space, and determining the relevant communication modes of the channel by rigorously applying the sampling theorem on the field's vector space.One consequence, for narrow-band frequency transmission, is that space and time can be decoupled, leading to a space-time information duality principle in the computation of the capacity of the radiating system. Interestingly, in the case of wide-band frequency transmission, a much more complex scenario arises, as it turns out that time and space cannot be decoupled and they jointly characterize the wave's information content.Bio: Massimo Franceschetti is assistant professor in the Department of Electrical and Computer Engineering of University of California at San Diego. He received the Laurea degree, magna cum laude, in Computer Engineering from the University of Naples in 1997, and the M.S. and Ph.D. degrees in Electrical Engineering from the California Institute of Technology in 1999, and 2003. Before joining UCSD, he was a post-doctoral scholar at University of California at Berkeley for two years.Prof. Franceschetti was awarded the C.H. Wilts Prize in 2003 for best doctoral thesis in Electrical Engineering at Caltech; the S.A Schelkunoff award in 2005 (jointly with profs. J. Bruck and L. J. Shulman) for best paper in the IEEE Transactions on Antennas and Propagation; and an NSF CAREER award in 2006.He has held visiting positions at at the Vrije Universiteit Amsterdam in the Netherlands, the Ecole Polytechnique Federale de Lausanne in Switzerland, and the University of Trento in Italy.His research interests include random networks for communication, wave propagation in random media, and control over networks. He is currently associate guest co-editor of the IEEE Transactions on Information Theory, special issue on relay and cooperation in networks and the IEEE Journal on Selected Areas in Communications, special issue on Communication and Control.Host: Urbashi Mitra, ubli@usc.edu

Location: Frank R. Seaver Science Center (SSC) - 319

Audiences: Everyone Is Invited

Contact: Mayumi Thrasher