Broadcasting without Knowing the Channel: Outage-Efficient Transmission

SPEAKER: Dr. Wenyi Zhang, Post-Doc, CSIABSTRACT: A prevailing assumption in multiuser information theory is that the transmitter(s) has perfect channel state information (CSI). However, transmit CSI may not be readily available under certain scenarios, for example, in fading channels, or in lack of an adequate feedback link. In this talk, we investigate a fading Gaussian broadcast channel (BC) without transmit CSI. Specifically, we consider a quasi-static scenario, to model delay-sensitive applications over slowly time-varying fading channels, and characterize system performance by outage achievable rate regions. For scalar-input channels, we propose two coding schemes: blind dirty paper coding (B-DPC), and statistical superposition coding (S-SC). Both schemes lead to the same outage achievable rate region, which always dominates that of time-sharing, irrespective of the particular fading distributions. We also show that the S-SC scheme can be extended to BCs with multiple transmit antennas. (Joint work with S. Kotagiri and J. N. Laneman)BIO: Wenyi Zhang was born in Chengdu, Sichuan, China in 1979. He received B.E. degree in Automation from Tsinghua University, Beijing, China in 2001; and M.S. and Ph.D. degrees in Electrical Engineering both from the University of Notre Dame, in 2003 and 2006, respectively. He is now affiliated with the Communication Sciences Institute (CSI), the University of Southern California (USC), as a postdoctoral research associate. He was awarded the Michael J. Birck Endowed Graduate Fellowship in 2002-2003, and the Center for Applied Mathematics (CAM) Fellowship of the University of Notre Dame in summer 2004 and 2005-2006. He received the Kaneb Graduate Student Award for Excellence in Teaching in 2005. He is a member of IEEE and Sigma Xi.

Location: Hughes Aircraft Electrical Engineering Center (EEB) - 539

Audiences: Everyone Is Invited

Contact: Mayumi Thrasher