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Events for May 24, 2007
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Optimizing Frequency Reuse in Ad-Hoc Networks
Thu, May 24, 2007 @ 02:00 PM - 03:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
SPEAKER: Prof. Nihar Jindal, University of MinnesotaAbstract: The issue of frequency reuse is investigated for ad-hoc networks in which many uncoordinated transmissions occur over shared spectrum. The following question is considered: given a fixed total bandwidth and a fixed rate requirement for each single-hop transmitter-receiver link in the network, what fraction of the total available bandwidth should be utilized by each transmission (or alternatively, at what point along the bandwidth-SINR tradeoff-curve should the system operate at) in order to maximize the spatial density of transmissions? Using stochastic geometry based results on ad hoc networks, it is shown that the optimal spectral efficiency lies between the low-SNR (power-limited) and high-SNR (bandwidth-limited) regimes and is a (increasing) function only of the path loss exponent. The network operates at this optimal point by dividing the system bandwidth into appropriately sized sub-bands and having each transmission occur over one of the sub-bands at the optimal spectral efficiency. Using this result, it is possible to derive simple relationships between information density and various system parameters such as communication range, outage probability, and rate. This work was jointly conducted with Jeff Andrews of UT Austin and Steven Weber of Drexel University.Joint work with Jeff Andrews and Steven WeberBio: Nihar Jindal received the B.S. degree in Electrical Engineering and Computer Science from U.C. Berkeley in 1999, and the M.S. and Ph.D. degrees in Electrical Engineering from Stanford University in 2001 and 2004. He is an assistant professor in the Department of Electrical and Computer Engineering at the University of Minnesota, where he holds a McKnight Land-Grant Professorship from 2007-2009. His research spans the fields of information theory and wireless communication, with specific interests in multiple-antenna/multi-user channels, dynamic resource allocation, and sensor and ad-hoc networks. Dr. Jindal was the recipient of the 2005 IEEE Communications Society and Information Theory Society Joint Paper Award.Host: Giuseppe Caire, caire@usc.edu
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
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On Three Water Waves Problems
Thu, May 24, 2007 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker:Professor Frederic Dias,
Head of the Fluid Mechanics Group,
Centre de Mathematiques et de Leurs Application,
Ecole Normale Superiuere de CachanOn Three Water Waves Problems1) Fault dynamics and tsunami generation
2) Boussinesq System of internal waves
3) Effects of viscosity on water wavesLocation: Kaprielian Hall (KAP) - rielian Hall, 203
Audiences: Everyone Is Invited
Contact: Evangeline Reyes