Sennur Ulukus U of Maryland, Coll Park
The increase in the number of users, and proliferation of the services which require high bit-rates, combined with the scarcity of the wireless bandwidth, make it more important than ever to develop technologies, techniques and algorithms to make the most efficient use of the available resources. The goal of this research is to understand and determine the ultimate capacity limits of wireless communication networks, and develop techniques and algorithms to achieve or approach these capacity limits. An important consequence of this research will be the development of principles and guidelines for the design of future wireless networks.
The focus of this research is the design of, and algorithm development for, the physical and medium access control (MAC) layers of multiuser vector multiple access channels. This research targets realistic and important system conditions of multiple-transmitter multiple-receiver networks (multi-cell cellular, and more generally, ad-hoc networks), asynchronous reception, dispersive channels with nter-symbol-interference(ISI), and fading channels. The investigator studies the design of optimum multiuser transmit strategies with the aim of maximizing the overall network capacity. Here, the transmit strategy means, for each user, the decision of the user to transmit or not, at any given fading and interference state, and the power and the vector it uses in its transmission, if it decides to transmit. The receiver optimization is incorporated as well, when applicable. The investigator studies the development of feedback- and measurement-based, highly-adaptive, distributed and iterative algorithms for the construction of network-wide optimum transmit strategy ensembles.
