Medium Access Control in Wireless Networks with Multipacket Reception: Signal Processing and Optimal Protocol

EECS Joint Colloquium Distinguished Lecture Series

Qing Zhao
Cornell University
Faculty Candidate

Wednesday, March 14, 2001
Hewlett Packard Auditorium, 306 Soda Hall
4:00-5:00 p.m.


High throughput networking has been approached solely via the medium access control (MAC) layer under a collision channel model where a concurrent transmission of two or more packets results in the destruction of all the transmitted information. Realizing that throughput is affected by the reception capability of the channel as well as the efficiency of the MAC protocol, we approach high performance networking from both the physical layer and the MAC layer. At the physical layer, we introduce multipacket reception (MPR) by developing signal processing techniques that enable the separation of packets simultaneously transmitted through dispersive channels. At the MAC layer, we design an optimal protocol to fully exploit this MPR capability. In this talk, we focus on the problem of optimal protocol design for general MPR channels, which has not been addressed in the literature. We propose a protocol that, by optimally exploiting the feedback information, maximizes the per-slot throughput under a set of heterogeneous delay constraints. It is capable of handling users with different Quality-of-Service (QoS) requirements. It achieves the maximum possible throughput among all protocols at heavy traffic load and has small delay when the traffic load is light.


Qing Zhao is currently a Ph.D. student at the School of Electrical and Computer Engineering, Cornell University. She received the B.S. degree in Electrical Engineering in 1994 from Sichuan University, Chengdu, China, and the M.S. degree in 1997 from Fudan University, Shanghai, China. Her research interests lie in the intersection of signal processing, wireless communications, and communication networks. She has been working on adaptive receiver design for wireless communication systems, signal processing for communication networks, and optimal medium access protocol design for multiaccess communication networks. She was recently selected to receive the IEEE Signal Processing Society 2000 Young Author Award.