Speaker:

Dr. Hai Jiang, Assistant Professor

Department of Electrical and Computer Engineering

University of Alberta, Canada

Abstract:

Optimal multi-channel cooperative sensing strategies in cognitive radio networks are investigated. A cognitive radio network with multiple potential channels is considered. Secondary users cooperatively sense the channels and send the sensing results to a coordinator, in which energy detection with a soft decision rule is employed to estimate whether there are primary activities in the channels. An optimization problem is formulated, which maximizes the throughput of secondary users while keeping detection probability for each channel above a pre-defined threshold. In particular, two sensing modes are investigated: slotted-time sensing mode and continuous-time sensing mode. With a slotted time sensing mode, the sensing time of each secondary user consists of a number of mini-slots, each of which can be used to sense one channel. The initial optimization problem is shown to be a nonconvex mixed-integer problem. A polynomial-complexity algorithm is proposed to solve the problem optimally. With a continuous-time sensing mode, the sensing time of each secondary user for a channel can be any arbitrary continuous value. The initial nonconvex problem is converted into a convex bilevel problem, which can be successfully solved by existing methods.

Speaker’s bio:

HAI JIANG received the B.Sc. degree in 1995 and the M.Sc. degree in 1998, both in electronics engineering, from Peking University, China and the Ph.D. degree in 2006 in electrical engineering from the University of Waterloo, Canada. Since July 2007, he has been an Assistant Professor at the Department of Electrical and Computer Engineering, University of Alberta, Canada. His research interests include radio resource management, cognitive radio networking, and cross-layer design for wireless multimedia communications. He received a Best Paper Award from IEEE GLOBECOM 2008. He served as a Co-Chair for the Wireless and Mobile Networking Symposium at the IEEE International Conference on Communications (ICC) 2010. He is an Associate Editor for the IEEE Transactions on Vehicular Technology.