Estimation and Capacity of Channels in Smart Antenna Wireless Communication Systems

Tuesday, August 3rd, 2:00 PM, ENS 602

torlak@ece.utexas.edu

Abstract

The proliferation of digital wireless communication services has been stimulating unprecedented demand for scarce radio spectrum. As the number of subscribers grows, spectral crowding and co-channel interference are becoming increasingly important issues. To alleviate such problems and to achieve the ambitious requirements introduced for existing and future wireless systems, attention has recently turned to spatial filtering methods using advanced antenna techniques: smart antennas. Smart antennas exploit the spatial dimension as a hybrid multiple access technique (space division multiple access-SDMA) for complementing FDMA, TDMA and CDMA to improve the quality and spectral efficiency of communications over wireless channels.

This talk develops new signal processing methods and drives upper bounds on capacity for smart antenna wireless communication systems. In particular, I study channel estimation for uplink and optimum weight vector design to maximize the downlink channel capacity. For uplink, I focus on blind multi-user channel estimation in code division multiple access wireless communication systems. For downlink, I investigate multi-transmitter broadcast systems. A multi-transmitter broadcast channel is a communication channel in which an antenna array system is transmitting to two or more receiving users. In order to optimize performance of the communications system, I must find the optimal weight vector for each message signal that maximizes the overall channel capacity.

A list of Telecommunications and Signal Processing Seminars is available at from the ECE department Web pages under "Seminars". The Web address for the Telecommunications and Signal Processing Seminars is http://anchovy.ece.utexas.edu/seminars