Abstract: This talk addresses one of the main issues in half-duplex relay systems: the well-known multiplexing loss due to the causality of relays. We propose relay selection methods to recover the multiplexing loss in decode-and-forward (DF) relay networks. A key feature of this work is that the interference of relays on each other are fully taken into account. Two network topologies are studied: relaying with and without direct source-destination links. For the former topology we design relay selection methods that achieve the MISO upper bound on the Diversity-Multiplexing Tradeoff (DMT) with very little feedback and no carrier synchronization requirements. For the latter topology we propose non-orthogonal DF methods that feature an unequal error protection ability via an embedded family of DMT curves. Even considering the latter method's minimal DMT, a marked improvement over previous DF methods is observed, especially in high spectral efficiencies. By addressing one of the most prominent drawbacks of relay systems, it is hoped that this work will pave the way to a more widespread acceptance of the usage of DF relays in communication networks.

Biography: Aria Nosratinia is professor of Electrical Engineering at the University of Texas at Dallas. His research interests are in the broad area of signal processing and communications. In particular, his recent work has been in the area of relays and cooperative and opportunistic communications and cross-layer issues. He received a Ph.D. in Electrical and Computer Engineering from the University of Illinois at Urbana-Champaign, and has held visiting positions in Princeton University, Rice University, and UCLA. He is an officer and member of board of governors of the IEEE Information Theory society, as well as associate editor for the IEEE Transactions on Information Theory and IEEE Transactions on Wireless Communications. In the past he has served as associate editor for IEEE Signal Processing Letters, IEEE Transactions on Image Processing, and IEEE Wireless Communications (magazine). Dr. Nosratinia is a recipient of the National Science Foundation career award and is a fellow of IEEE.