A.G. Cepni, "Time-Reversal Methods for Broadband Wireless Systems"
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  • A.G. Cepni, "Time-Reversal Methods for Broadband Wireless Systems"

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Faculty of Engineering and Natural Sciences
FENS SEMINARS

Time-Reversal Methods for Broadband Wireless Systems

Ahmet Gürkan Cepni,
Research Staff Member, Microwave Tech. Research Lab, Motorola, Schaumburg, IL, USA

 
Time-reversal is a novel method to utilize the multipath components in a cluttered environment for super-resolution focusing. The conventional thought about the adverse effects of multipaths on communication systems has been changing based on recent findings showing how to use multipath components to create independent paths between transmitter and receiver. Time-reversal schemes are one of these recent techniques which can convert the traditionally hostile multipaths into performance-boosting elements in a two-way communication system as well as target detection, and localization methods in a radar system.

Time-reversal techniques utilize the scattering of waves in the medium to improve the resolution of spatial and temporal focusing in multipath rich channels. The successful demonstrations of time-reversal experiments using low frequency waveforms in acoustics and ultrasonics have generated interest in time-reversal methods using radio-frequency electromagnetic waves. Time-reversal system performance depends on the available bandwidth, the multipath structure of the propagation channel and the number of sensors. These parameters present several challenges in the context of wireless applications and the optimum solution can be achieved by a trade-off analysis among the resources.

In this talk, we will investigate time-reversal methods using electromagnetic waves. We will show the experimental results on super-resolution focusing and nulling of radio signals and discuss applications to radar systems and wireless networks like 802.16 systems, UWB and sensor networks.

Ahmet Gürkan Cepni is currently a research staff member at Motorola Labs where he investigates RF smart antenna systems for next generation wireless devices. He received his B.S. degree in electrical and electronics engineering and in physics, both from Bogazici University, Istanbul, Turkey, in 2000 and the M.S. and PhD degrees in electrical and computer engineering from Carnegie Mellon University (CMU), Pittsburgh, PA, in 2002, and 2005 respectively. His research interests are intelligent radio architectures, RF/microwave systems, and propagation models.


November 29, 2006, 13:40, FENS G032