Cooperation in Wireless Networks: Node Assignment Strategies

Featuring:
Aria Nosratinia, Associate Professor of Electrical Engineering
University of Texas at Dallas

Abstract:

We consider cooperative wireless networks, in particular the non-altruistic variety where there are no pure relays and all nodes that are "on" have data of their own to transmit. In this context, we begin by presenting a coded cooperation framework, where cooperation is achieved in the context of channel coding. We then talk about node assignment strategies. In general, not all nodes in a wireless network wish to be involved in every transmission. So for a multi-node cooperation protocol, one needs strategies of grouping the nodes. We examine such strategies under two types of constraints:  distributed control and centralized control. We show that there exist simple distributed strategies that guarantee full diversity (in the number of decoding attempts) over the network. Since the distributed strategies already achieve full diversity, centralized control does not provide any additional diversity gain, however, based on various amounts of channel state information being available to the central controller, significant gains are still possible over and above distributed control. We characterize these gains under a variety of conditions.

About the Speaker:

Aria Nosratinia received his Ph.D. in Electrical and Computer Engineering from the University of Illinois at Urbana-Champaign. During the academic year 1995-96, he was with Princeton University, Princeton, New Jersey. From 1996 to 1999, he was a visiting professor and faculty fellow at Rice University, Houston, Texas. Since July 1999, he has been on the faculty of the University of Texas at Dallas, where he is now Associate Professor of Electrical Engineering. Currently he is spending a sabbatical leave at UCLA. His interests lie in the broad area of information theory, coding, and signal processing, in particular various problems related to wireless networks. He received the National Science Foundation career award in January 2000.  He serves as associate editor for the IEEE Transactions on Image Processing and IEEE Wireless Communications.