Collaborative Research: FRG: Time Reversal Techniques in Radar and Radio Communications

Stanford University, Stanford CA

Investigators

Abstract

Proposal: DMS-0354674 PI: George Papanicolaou PI: Institution: Stanford University Title: Collaborative Research: FRG: Time Reversal Techniques in Wireless Communications ABSTRACT This Focused Research Group project is a closely knit Math-EE collaboration that involves, in addition to the PI's, several students and postdoctoral visitors. Our goals cover physical channel modeling, experimental measurements, algorithm design and simulation of wireless communication systems in large delay spread environments. Physical modeling will help understand large delay spread channels in wireless environments. Experimental measurements will use a new, specially designed by this research group, wireless time reversal sounder to verify theoretical time reversal predictions. Mathematical algorithm design will deal with equalization complexity, working with imperfect channel estimates, pre-coding, etc., that arise in such problems. Systems simulations will help understand overall performance of time reversal communications in different deployment scenarios. In time reversal, signals transmitted with a time reversed filter back propagate and focus tightly in space-time near the intended receiver. The phenomena rely on large delay spread (rich multipath) channels. The space-time focusing is even more tight and robust when the propagation medium is randomly inhomogeneous. Recent experimental and theoretical studies have firmly established this remarkable effect and have motivated applications to detection, imaging and communications. We believe that these space-time focusing properties of time reversal can lead to a new class of wireless communications systems with significant advantages over current approaches. This technique converts a problem in wireless posed by multipath (which induces fading) into an opportunity for improved performance. There are many potential applications of these ideas in commercial wireless as well as in specialized systems, such as communication systems that demand low probability of intercept. Companion Proposal: 0354658 PI: Liliana Borcea Institution: Rice University