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Events for December 07, 2005
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Geographic Random Forwarding (GeRaF) for Ad Hoc and Sensor Networks
Wed, Dec 07, 2005 @ 10:30 AM - 11:30 AM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
CENG SEMINAR SERIES"Geographic Random Forwarding (GeRaF) for Ad Hoc and Sensor Networks"Prof. Michele ZorziSchool of EngineeringUniversity of Padova, ItalyABSTRACT:In this talk, we describe a novel forwarding technique based on geographical location of the nodes involved and random selection of the relaying node via contention among receivers. We first provide a description of the basic idea and study the multihop performance of the scheme. We then provide a detailed description of a MAC scheme based on these concepts and on collision avoidance, and report on its energy and latency performance. Using analysis and simulation, we show that the proposed technique is able to achieve significantly better performance than current schemes in some useful scenarios. Extension to more general metrics is also discussed.BIO:Michele Zorzi is a Professor of Telecommunications at the School of Engineering of the University of Padova, Italy. After obtaining his Ph.D. at the University of Padova, he was an Assistant Professor at Politecnico di Milano, a Research Scientist at UC San Diego, and a Professor at the University of Ferrara. His research interests are focused on wireless communications and networking. He is the Editor-in-Chief of the IEEE Wireless Communications Magazine, and has been on the Editorial Board of many journals and on the TPC of many conferences.Hosts: Prof. Ahmed Helmy, x11329 and Prof. Bhaskar Krishnamachari, x12528
Location: Hughes Aircraft Electrical Engineering Center (EEB) - -248
Audiences: Everyone Is Invited
Contact: Rosine Sarafian
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Pizza Day for EE Students (only)
Wed, Dec 07, 2005 @ 11:30 AM - 12:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
University Calendar
Please come for lunch
Pizza and soda
Location: Between EEB and RTH
Audiences: EE Department Only
Contact: Diane Demetras
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Protograph Based LDPC Codes with Minimum Distance Linearly Growing with Block Size
Wed, Dec 07, 2005 @ 02:15 PM - 03:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speakers: Dariush Divsalar and Chris Jones, Jet Propulsion LaboratoryAbstract: We propose several LDPC code constructions that simultaneously achieve good threshold and error floor performance. By considering ensemble average weight enumerators, minimum distance is shown to grow linearly with block size (similar to regular codes of variable degree at least 3). Our constructions are based on projected graph, or protograph, structures that support high-speed decoder implementations. As with irregular ensembles, our constructions are sensitive to the proportion of degree-2 variable nodes. A code with too few such nodes tends to have an iterative decoding threshold that is far from the capacity threshold while a code with too many such nodes tends to not exhibit a minimum distance that grows linearly in block length. In this paper we also show that precoding can be used to lower the threshold of regular LDPC codes. A family of low to high rate codes with minimum distance linearly increasing in block size and with capacity approaching performance thresholds is presented. FPGA simulation results for a few example codes show that the proposed codes perform as predicted. Encoders for the proposed codes will be discussed.Research presented is the work of D. Divsalar, C. Jones, S. Dolinar, and J. Thorpe of Jet Propulsion Laboratory, California Institute of Technology.Bios: Dariush Divsalar received Ph.D. degree in EE from UCLA in 1978. Since then, he has been with the Jet Propulsion Laboratory, California Institute of Technology, where he is a principal scientist. During past 20 years, he taught graduate courses at UCLA and Caltech. He has published over 150 papers, coauthored three books and holds ten U.S. patents in the above areas. Recently, one of his papers has been selected as one of the key research papers published by the IEEE Communications Society during the past five decades. He has received over 25 NASA Tech Brief awards and a NASA Exceptional Engineering Achievement Medal in 1996. He served as Editor for the IEEE Transactions on Communications from 1989 to 1996. Dr. Divsalar is a Fellow of IEEE.Christopher R. Jones received BS, MS, and Ph.D. degrees in Electrical Engineering from UCLA in 1995, 1996, and 2003. From 1997 to 2002 Dr. Jones worked with Broadcom Corporation in the area of VLSI architectures for communications systems. Since Jan. 2004 he has been with the Jet Propulsion Laboratory where he works on problems related to modulation, code design, hardware architectures for encoding/decoding, synchronization, and modulation. Dr. Jones has published a combination of 40 papers and patents.Host: Professor Giuseppe Caire, caire@usc.edu, x.04683
Location: Hughes Aircraft Electrical Engineering Center (EEB) - -248
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
