ABSTRACT: Cognitive radio networks enable secondary users to utilize spare bandwidth of primary users by limiting their interference. Moving beyond the traditional listen-before-talk paradigm, we propose a cognitive access methodology that exploits the feedback channel in two-way primary communication links for better spectrum utility and protection of primary users against secondary interference. We let secondary users dynamically control access and power based on primary ACK/NACK messages. We develop an optimal access policy applicable to multiple secondary user pairs. We also devise a distributed power control policy for multiple secondary users to maximize their individual throughput without significant cumulative interference to the primary link. Our distributed access and power control schemes can effectively provide good SU performance and primary protection without requiring central coordination.
SPEAKER: Dr. Ding is a Professor of Electrical and Computer Engineering. He received the B.S. degree from Nanjing Institute of Technology in 1982, M.A.Sc. degree from the University of Toronto in 1987, and the Ph.D. degree from Cornell University in 1990, all in electrical engineering. He is currently Professor of Electrical and Computer Engineering, University of California, Davis, CA. His research contributions cover a broad range of signal processing and communication problems including wireless transceiver optimization, blind channel estimation and equalization, multi-input-multi-output communications, multiuser detection, source separation, adaptive signal processing, parameter estimation, radar target discrimination, multimedia wireless communications, and cross-layer wireless communications. He has published over 200 refereed papers and book chapters. Dr. Ding has served on a number of technical programs for SPS workshops and conferences. He was associate editor for IEEE Transactions on Signal Processing from 1994-1997 and again from 2001-2004. He also served as associate editor of IEEE Signal Processing Letters from 2002-2005. He was a member of technical committee on Statistical Signal and Array Processing, member of technical committee on Signal Processing for Communications (1994-2003), and a member of the IEEE SPS Technical Committee on Multimedia Signal Processing(2001-2006). He was a member of the Editorial Board for the IEEE Signal Processing Magazine. Dr. Ding was on the Organization Committee of ICASSP 2005 in Philadelphia. He was the Technical Program Chair of the 2006 IEEE Globecom. Dr. Ding is a Fellow of the IEEE. Dr. Ding is named 2004-06 Distinguished Lecturer by the IEEE Circuits and Systems Society. He also received the IEEE Outstanding Instructor of the Year Award in 2002 for contributions to electrical engineering education from the IEEE student section in University of California, Davis. Dr. Ding has held visiting positions in Australian National University, Hong Kong University of Science and Technology, NASA Lewis Research Center, and USAF Wright Laboratory. Prof. Ding has active collaboration with researchers from several regions including Australia, China, Japan, Canada, Taiwan, Korea, Singapore, and Hong Kong. He is also a visiting professor of the Southeast University in Nanjing, China.
