ECE Department Calendar
Dr. Harpreet Dhillon, Postdoctoral Research Associate
University of Southern California – Los Angeles
When: Friday, February 28, 2014 at 3:05 p.m.
Where: Warnock 1230
The increasing complexity of heterogeneous cellular networks (HetNets) due to the irregular deployment of small cells demands significant rethinking in the way cellular networks are perceived, modeled and analyzed. In addition to threatening the relevance of classical models, this new network paradigm also questions the feasibility of state-of-the-art simulation-based approach for system design. In this talk, I will discuss an alternate approach based on random spatial models that is not only tractable but also captures current deployment trends fairly accurately.
First, I will present a general baseline model consisting of K different types of base stations (BSs) that may differ in terms of transmit power, deployment density and target rate. Modeling the locations of each class of BSs as an independent Poisson Point Process (PPP) allows the derivation of surprisingly simple expressions for key performance metrics. One interpretation of these results is that adding more BSs or tiers does not necessarily change the coverage probability, which indicates that the fears of “interference overload” in HetNets are probably overblown.
Second, I will discuss how the baseline model can be generalized to study self-powered HetNets, where each BS is powered solely by a self-contained energy harvesting module that may differ across tiers in terms of the energy harvesting rate and energy storage capacity. Since a BS may not always have sufficient energy, it may not always be available to serve users. This leads to a notion of “availability region”, which characterizes the fraction of time each type of BS can be made available under a variety of operational strategies. The availability region also provides a way to quantify performance degradation due to the unreliability associated with energy harvesting.
Time permitting, I will also discuss a few more topics of current interest, most notably: (i) multi-antenna HetNets, and (ii) ongoing work on wireless backhaul networks.
Harpreet S. Dhillon received the B.Tech. in Electronics and Communication Engineering from Indian Institute of Technology (IIT) Guwahati, India, in 2008, the M.S. in Electrical Engineering from Virginia Tech, Blacksburg, VA, in 2010, and the Ph.D. in Electrical Engineering from the University of Texas (UT) at Austin, TX, in 2013. Since Fall 2013, he is a postdoctoral research associate in the Communication Sciences Institute (CSI), Department of Electrical Engineering, University of Southern California (USC), Los Angeles, CA. He has held summer internships at Alcatel-Lucent Bell Labs in Crawford Hill, NJ, Samsung Research America in Dallas, TX, Qualcomm Inc. in San Diego, CA, and Cercom, Politecnico di Torino in Italy.
Dr. Dhillon is a recipient of the IEEE International Conference in Communications (ICC) 2013 best paper award in Wireless Communications Symposium, UT Austin’s Wireless Networking and Communications Group (WNCG) leadership award 2013, UT Austin’s Microelectronics and Computer Development (MCD) fellowship, and the Agilent Engineering and Technology Award 2008, a national award for the best undergraduate research thesis in India. His research interests are broadly in communication theory, stochastic geometry, and wireless ad hoc and cellular networks. For more details, please refer to: https://webspace.utexas.edu/hd3496/www/.
Dr. Gonzalo Mateos, Visiting Scholar
Carnegie Mellon University
When: Monday, March 3, 2014 at 3:05 p.m.
Where: Warnock 1230
The information explosion propelled by the advent of personal computers, the Internet, and the global-scale communications has rendered statistical learning from “Big Data” increasingly important for analysis and processing. Along with data adhering to postulated models, present in large volumes of data are also those that do not — and are referred to as outliers. In this talk, I will start with an approach to outlier-resilient principal component analysis, which establishes a neatlink between the seemingly unrelated notions of sparsity and robustness to outliers, even when the signals involved are not sparse. I will argue that controlling sparsity of model residuals leads to statistical learning algorithms that are computationally affordable and universally robust. The impact of these ideas will be demonstrated in applications as diverse as identification of aberrant responses in personality assessment surveys, and unveiling communities in social networks, as well as intruders from video surveillance data. In the second part of the talk, I will switch focus towards the important task of unveiling and mapping-out network traffic anomalies given link-level traffic measurements. Leveraging the low intrinsic-dimensionality of end-to-end network flows and the sparse nature of anomalies, I will construct an estimated map of anomalies in real time to aid in monitoring the network health state. If time allows, I will finally highlight anew additional domains that include predicting network-wide path latencies, and load curve cleansing and imputation — a critical task in green grid analytics and energy management with renewables.
Gonzalo Mateos was born in Montevideo, Uruguay, in 1982. He received his B.Sc. degree in Electrical Engineering from Universidad de la Republica, Uruguay, in 2005, and the M.Sc. and Ph.D. degrees in Electrical Engineering from the University of Minnesota (UofM), Twin Cities, in 2009 and 2011.From 2004 to 2006, he worked as a Systems Engineer at Asea Brown Boveri (ABB), Uruguay. Currently, he is a visiting scholar with the Computer Science Department at Carnegie Mellon University. He also holds an appointment as a post-doctoral research associate with the Department of Electrical and Computer Engineering (ECE) and the Digital Technology Center, UofM. His research interests lie in the areas of statistical learning from Big Data, network science, wireless communications, and signal processing. His current research focuses on algorithms, analysis, and application of statistical signal processing tools to dynamic network health monitoring, social, power grid, and Big Data analytics. Since 2012, he serves on the Editorial Board of the EURASIP Journal on Advances in Signal Processing. He received the Best Student Paper Award at the 13th IEEE Workshop on Signal Processing Advances in Wireless Communications, 2012 held at Cesme, Turkey, and was also a finalist of the Student Paper Contest at the 14th IEEE DSP Workshop, 2011 held at Sedona, Arizona, USA. His doctoral work has been recognized with the 2013 UofM’s Best Dissertation Award (Honorable Mention) across all Physical Sciences and Engineering areas.
Dr. Masoud Honarvar Nazari, Post Doctoral Fellow
Georgia Institute of Technology
When: Friday, March 7, 2014 at 3:05 p.m.
Where: Warnock 1230
In this talk, I will first discuss needs for transforming today’s fossil-fuel dependent and highly polluting electric power systems into sustainable, efficient, and reliable electric energy systems, which have functionalities similar to Internet.
Next, I will present my recent efforts to design a distributed decision-making and control architecture for internet-like energy systems. I will discuss the fundamental differences between internet-like distribution energy systems and conventional transmission power systems, regarding dynamic behavior under a high penetration of distributed generators.
Then, I will present a novel distributed frequency regulation architecture, whereby frequency regulators communicate with their neighbors in the network in order to improve performance. I will show that despite the frequency regulators being distributed, stability can be ensured while avoiding inter-area oscillations using a limited control effort. The efficacy of the proposed frequency regulation framework is shown through simulations on two real-world electric energy systems of different scale and complexity.
Masoud Honarvar Nazari is a Post Doctoral Fellow in the School of Electrical and Computer Engineering at Georgia Institute of Technology. He received his first Ph.D. in Electrical and Computer Engineering in a joint program between Carnegie Mellon University and the University of Porto, Portugal in 2012 and obtained his second Ph.D. in Engineering and Public Policy from Carnegie Mellon in the same year. He was a visiting scholar at MIT Energy Initiative in 2010. He was also awarded the five-year international FCT (Fundação para a Ciência e a Tecnologia) fellowship in 2007. His research interests include Power System and Smart Grid operation; Distributed Control Architecture for Internet-like Energy Systems; Large-scale Integration of Distributed Energy Sources, and; Policy implication and regulation design for modernizing Electric Power Systems. He has several book chapters, journals, and conference papers in the subject of Power System Stability and Control.
Mr. Tom Armstrong, Chief Technologist for Broadband Communication Systems
Applied Signal Technology – Raytheon Space and Airborne Systems
When: Monday, March 17, 2014 at 3:05 p.m.
Where: Warnock 1230
The Global Telecommunication Network touches our lives daily, and many do not appreciate the complexity of the network. This talk introduces fundamental engineering concepts of the network in a simplified view, and shows that the evolution of the core network in meeting today’s communication needs has not changed since the late 1800s.
Tom Armstrong is the chief technologist for Broadband Communication Systems in the Applied Signal Technology mission area of Raytheon Space and Airborne Systems. In this role, he provides direction and vision in all technical aspects of signal communications and intelligence product and system development and deployment: aspects including product design, system integration and test, operations and maintenance, and mission management and analysis. He is also a Raytheon Applied Signal Technology Senior Fellow and in such capacity he directs research and development in advanced modulation, high speed switching, error correction, signal multiplexing, communication protocols, and signal processing technologies.Prior to joining Raytheon Applied Signal Technology in 1999, Armstrong enjoyed a twelve-year career at the U.S. Department of Defense. He served in many technical capacities. In his final position with the DoD, he served as Technical Director of one of the operational divisions where he oversaw all aspects of design, development, and deployment of multiple signal communications systems. Mr. Armstrong earned his bachelor and master degrees in electrical engineering from the University of Utah in 1986 and 1987, respectively. On two different occasions—in 1997 and again in 2004—he received a Meritorious Citation from the US Government for exceptional achievement and superior performance which contributed significantly to the deployment of a major technical system of national importance.