Operating Point for MIMO Multiple Access Channel with Delay Sensitive Bursty Traffic

SPEAKER: Professor Tara Javidi, UC San DiegoAbstract: Multiple antennas at the transmitters and receivers in a multiple access channel (MAC) can provide simultaneous diversity, spatial multiplexing, and space-division multiple access gains. The fundamental tradeoff in the asymptotically large SNR regime is shown by Tse et al (2004). On the other hand, MAC scheduling can provide a statistical multiplexing gain to improve the delay performance as shown by Bertsimas et al (1998).In this talk, we provide a combined analysis in an attempt to unify the gains provided by a MIMO MAC. In partiucalr, we formulate and analytically derive an order optimal operating point for MIMO-MAC channel for bursty sources with delay constraints. Our system model brings together the four types of gains: diversity, spatial multiplexing, space-division multiple-access provided at the PHY layer, and statistical multiplexing gains at the MAC scheduler. Our objective is to minimize the end-to-end performance as defined by the delay bound violation probability as well as the channel decoding error probability. We first find the order optimal diversity gain for a point-point MIMO communication and then extend the result to the case of MAC. Considering a MIMO MAC with CSI at the receiver, we find the optimal diversity gain and rate region in which the system should operate. In this, we arrive at an interesting interplay between the intensity of the traffic and resource pooling with regard to both multiple-access and statistical multiplexing gains.Bio: Tara Javidi studied electrical engineering at Sharif University of Technology, Tehran, Iran from 1992 to 1996. She received the MS degrees in electrical engineering (systems), and in applied mathematics (stochastics) from the University of Michigan, Ann Arbor, in 1998 and 1999, respectively. She received her Ph.D. in electrical engineering and computer science from the University of Michigan, Ann Arbor, in May 2002. From 2002 to 2004, she was an assistant professor at the Electrical Engineering Department, University of Washington, Seattle. She joined University of California, San Diego, in 2005, where she is currently an assistant professor of electrical and computer engineering. She was a Barbour Scholar during 1999-2000 academic year and received an NSF CAREER Award in 2004.Her research interests are in communication networks, stochastic resource allocation, stochastic control theory, and wireless communications. Host: Bhaskar Krishnamachari, bkrishna@usc.edu

Location: Frank R. Seaver Science Center (SSC) - 319

Audiences: Everyone Is Invited

Contact: Mayumi Thrasher