FENS SEMINAR ANNOUNCEMENT

"Interference Prediction, Avoidance and Mitigation in Multihop Wireless
Networks"

Ufuk Tureli, Ph.D.
November 26, 2010, FENS L067, 13:40
 
Abstract:

Interference in the physical layer of wireless networks is due frequency
reuse. We present novel analytical and experimental studies on dynamic
spectrum reuse. For effective resource allocation which uses scheduling
for 3G cellular systems, we developed analytic expressions for the
distribution of predicted signal to interference ratio in an
uncoordinated multi-cell 3G EVDO network with a frequency reuse factor
of 1 and verified prediction with real world data collected by Lucent.
This has been used to develop a practical scheduler with minimal
capacity loss subject to an outage constraint.  

Multiple hopping can be used to enhance the throughput, network coverage
and capacity for indoors and outdoors in infrastructure networks. We
examine improvement in outage capacity with a single relay for indoor
coverage with significant building insertion loss first. Recently,
hybrid wireless networks which take on the best features of
infrastructure and ad hoc networks have been proposed for 4G networks.
Spatial variability of spectrum use observed in broadband spectrum
occupancy measurements  motivate a novel framework exploit spectrum
which allows a significant improvement in bandwidth efficiency and
capacity by considering spectrum holes in the spatial domain as well as
the temporal domain. We examine  an outdoor cognitive network can be
implemented within a primary system, to assist disadvantaged users while
minimizing interference and satisfying protection constraints by
judicious power control and scheduling.

Multiple hopping is a key feature of ad hoc networks, but lacking a
centralized controller, interference mitigation is a major problem. This
problem can be avoided using multiple antennas at transmitters and
receivers. Closed loop feedback multiple input multiple output (MIMO) ad
hoc network can greatly improve system performance at a cost of
significant signaling overhead and/or exploiting reciprocity between
transmitter and receiver channels, limiting suitability to dynamic
interference and information. Reduced feedback MIMO in an ad hoc network
is implemented. A distributed game is formulated and is shown to
converge using numerical analysis. Open problems and preliminary work
for next generation ad hoc networks with multiple radio frequency (RF)
chains suitable  for dynamic channel and MIMO configuration.

Short Biography:
Ufuk Tureli  received the B.Sc. degree from Bogazici University,
Istanbul, Turkey and the M.S. and Ph.D. degrees from the University of
Virginia, Charlottesville, Virginia in 1998 and 2000 respectively, all
in electrical engineering. Since January 2008, he is an associate
professor and Director of the Radio Frequency Laboratory in the
Department of Electrical and Computer Engineering, West Virginia
University Institute of Technology, Montgomery, WV.
From July 2000- December 2007, Dr. Tureli was an assistant professor,
director of wireless research laboratory in the  Electrical and Computer
Engineering Department and From Sep 2005-December 2007 associate
director of the Wireless Network Security Center, Stevens Institute of
Technology, Hoboken, NJ,  His research is scalable and robust wireless
networks from  physical  to network layers. His current research focuses
on interference prediction, cross layer design, and spatial reuse of
spectrum .

Dr. Tureli is a member of the IEEE Communications Society, serves in
technical program committees (TPC) for IEEE Globecom, Milcom, ICC and
WCNC conferences as well as the IEEE Communications Society (COMSOC)
Radio Communications Committee. He is on the Editorial Board of the
Elsevier Physical Communication (PHYCOM)  Journal and serves as an
Associate Editor. Dr. Tureli was an Associate Editor for IEEE
Transactions on Vehicular Technology in 2009.