Distinguished Prof. Athina Petropulu, ECE Department at Rutgers, to speak at ECE-NTUA on February 4, 2020, at 12:00 (Multimedia amphitheater, Central Library of NTUA)
Lecture Title: Model-based and Model Free Mobile Relay Beamforming Networks
Abstract: Distributed, networked communication systems, such as relay beamforming networks are typically designed without considering how the positions of the respective nodes might affect the quality of the communication. That is, network nodes are either assumed to be stationary in space, or, if some of them are moving while communicating, their trajectories are assumed to be independent of the respective communication task. However, in most cases, the Channel State Information (CSI) observed by each network node, per channel use is both spatially and temporally correlated. One could then ask whether the performance of the communication system could be improved by predictively controlling the positions of the network nodes (e.g., the relays), based on causal CSI estimates and by exploiting the spatiotemporal dependencies of the communication medium. In this talk, we address the problem of enhancing Quality-of-Service (QoS) in power constrained, mobile relay beamforming networks, by optimally exploiting relay mobility. We consider a time slotted system, where the relays update their positions before the beginning of each time slot. Adopting a spatiotemporal stochastic field model of the wireless channel, we present a novel 2-stage stochastic programming formulation for specifying the relay positions at each time slot, such that the QoS of the network is maximized on average, based on causal CSI and under a total relay transmit power budget. The motion control problem considered is shown to be approximately equivalent to a set of simple subproblems, which can be solved in a distributed fashion, one at each relay. The motion control problem is also formulated as a model-free reinforcement learning problem, based on Q-learning. The model-free policy exhibits performance that is slightly inferior to that of the model-based, however, its reduced computational complexity and the fact that it does not require CSI estimates may be more important in practical applications.
Short Bio: Athina P. Petropulu is Distinguished Professor at the Electrical and Computer Engineering (ECE) Department at Rutgers, having served as chair of the department during 2010-2016. Prior to joining Rutgers she was a Professor of ECE at Drexel University (1992-2010). She held Visiting Scholar appointments at SUPELEC, Universite’ Paris Sud, Princeton University and University of Southern California. Dr. Petropulu's research interests span the area of statistical signal processing, wireless communications, signal processing in networking, physical layer security, and radar signal processing. Her research has been funded by various government industry sponsors including the National Science Foundation (NSF), the Office of Naval research, the US Army, the National Institute of Health, the Whitaker Foundation, Lockheed Martin and Raytheon.
Dr. Petropulu is Fellow of IEEE and AAAS and recipient of the 1995 Presidential Faculty Fellow Award given by NSF and the White House. She is President-Elect for the IEEE Signal Processing Society for 2020-2021. She has served as Editor-in-Chief of the IEEE Transactions on Signal Processing (2009-2011), IEEE Signal Processing Society Vice President-Conferences (2006-2008), and is currently member-at-large of the IEEE Signal Processing Board of Governors. She was the General Chair of the 2005 International Conference on Acoustics Speech and Signal Processing (ICASSP-05), Philadelphia PA, and is General Co-Chair of the 2018 IEEE International Workshop on Signal Processing Advances in Wireless Communications (SPAWC). She is recipient of the 2005 IEEE Signal Processing Magazine Best Paper Award, and the 2012 IEEE Signal Processing Society Meritorious Service Award. She was Distinguished Lecturer for the Signal Processing Society for 2017-2018, and is currently Distinguished Lecturer for the IEEE Aerospace & Electronics Systems Society.
The event is organized by the Division of Signals, Control and Robotics of ECE-NTUA.