This talk presents recent results on relay selection and cooperative partner selection, under various amounts of channel state information. I first consider non-altruistic cooperation in orthogonal channels (no dedicated relays) with only receive-side channel-state information (CSI). Each node is unaware of location and channel gains of other nodes. I show that even under these conditions, local node selection strategies exist to guarantee network-wide full diversity. Then I discuss increasing amounts of CSI and how they improve cooperative gains. Performance bounds under an omniscient network controller are demonstrated.

Time permitting, I will talk about opportunistic cooperation with limited feedback, where it is shown that only two bits of information per user is sufficient to ensure optimal diversity-multiplexing tradeoff, in the case of opportunistic cooperation with dedicated relays. This is a significant advancement over previous methods that required network-wide full CSI at the nodes to achieve opportunistic cooperation.

Hosts: Behnaam Aazhang and Ashu Sabharwal

Biography of Aria Nosratinia:
Aria Nosratinia is associate professor of electrical engineering at the University of Texas at Dallas. He attended University of Tehran (BS), University of Windsor (MS), and University of Illinois at Urbana-Champaign (PhD). He has had visiting stints at Princeton, Rice University, and UCLA. He was the recipient of NSF Career award and two chapter awards for service to IEEE, and is on the editorial board of several IEEE journals. His general interests are in information theory, coding, signal processing, and their applications in wireless networks.