2019 Seminars

Spring 2019

Date: March 8, 2019

Speaker:  Parker White, Hume Center at Virginia Tech

Title: "Blind Frequency Hopping Spread Spectrum Source Separation with Constrained Clustering"

Abstract:  Frequency Hopping Spread Spectrum (FHSS) communication is a digital communication technique commonly used for its narrow band interference resistance as well as its low probability of detection. For this reason, FHSS is typically preferred when narrow-band interference is highly probable, or unintended listeners with the intention of jamming may be present. In either case, if a consistent problem interferer is present, the identification of this interferer is crucial for threat analysis and communication link integrity. As machine learning aided spectrum sensing techniques improve, the detection and estimation of frequency hopping characteristic parameters can be used to distinguish signal sources and identify a consistent problem interferer. Classical distance based clustering is a common technique in grouping a set of objects based on the similarity of their parameter sets. However, this technique does not account for any background knowledge that may be present in the problem scenario. Utilizing background knowledge in the form of instance level pairwise constraints can improve clustering performance in the application of frequency hopping signal separation.

Bio: Parker White is currently working on a Master of Science in electrical engineering under Dr. Buehrer and Dr. Headley. He received his undergraduate degree from West Virginia University with an emphasis in communications and signal processing. Parker plans on graduating late summer of this year. 


Date: March 1, 2019

Speaker:  Brad Brannon, Analog Devices

Title: "Challenges and Advancements in Next Generation Integrated Radio Technology"

Abstract:  Radio recently celebrated its 100th anniversary and yet it continues to evolve and change the way it impacts our daily lives.  For much of the last hundred years those architectures remained unchanged, yet in the last few years, the pace of evolution has increased as semiconductor technology removes old barriers and enable new topologies.  What obstacles has radio overcome in the past and what bumps exist in the road ahead?  What might the future of radio look like in the coming years?

Bio: Brad Brannon is a system architect and has worked at Analog Devices for 35 years following his graduation from North Carolina State University. At ADI he has held positions in design, test, applications, and in system engineering. Brad has authored a number of articles and application notes on topics that span clocking data converters, designing radios, and testing ADCs. Currently Brad is responsible for system engineering for 4G and 5G radio architectures.


Date: February 8, 2019

Speaker:  Joel Kees, Virginia Tech

Title: "Robust Blind Spectral Estimation in the Presence of Impulsive Noise"

Abstract: Robust nonparametric spectral estimation involves generating an accurate estimate of the Power Spectral Density (PSD) for a given set of data while trying to minimize the bias due to data outliers. This is applied in the domain of electrical communications and digital signal processing when a PSD estimate of the electromagnetic spectrum is desired (often for the goal of signal detection), and when the spectrum is also contaminated by Impulsive Noise (IN). Power Line Communication (PLC) is an example of a communication environment where IN is a concern because power lines were not designed with the intent to transmit communication signals. There are many different noise models used to statistically model different types of IN, but one popular model that has been used for PLC and various other applications is called the Middleton Class A model, and this model is extensively used in this thesis. The performance of two different nonparametric spectral estimation methods are analyzed in IN: the Welch method and the multitaper method. These estimators work well under the common assumption that the receiver noise is characterized by Additive White Gaussian Noise (AWGN). However, the performance degrades for both of these estimators when they are used for signal detection in IN environments. In this thesis, basic robust estimation theory is used to modify the Welch and multitaper methods in order to increase their robustness.    

Bio: Joel Kees is graduating with a Master of Science in electrical engineering under Dr. Beex. He received his undergraduate degree from Virginia Tech. In the spring, he will begin working full-time for LGS innovations in Northern Virginia. In his free time, he likes to read and mountain unicycle.  


Date: February 1, 2019

Speaker:  Dr. Charles Clancy, Virginia Tech Hume Center

Title: Security and Privacy for the 5G Core Network

Abstract: 5G introduces many new features, including new Radio Access Network (RAN) protocols to support higher data rates.  However, many of the exciting new features of 5G are within the core network.  Completely re-envisioned as a microservices architecture that can be elastically deployed within a cloud environment, 5G goes head-first into the world of Software-Defined Networking (SDN) enabled by Network Function Virtualization (NFV).  Using this toolbox, 5G introduces the concept of network slicing which allows vertical integration of networking services with the cloud and the ability to elastically deploy services.  This talk will provide a tutorial of these new features within 5G, with a specific focus on security and privacy issues associated with them. 

Bio: Dr. Charles Clancy is the Executive Director of Virginia Tech's Hume Center for National Security and Technology and is the Bradley Professor of Electrical and Computer Engineering. With 85 faculty and staff, the Hume Center engages over 400 students annually in research and experimental learning focused in national security and technology. Dr. Clancy is an internationally-recognized expert at the intersection of wireless, cybersecurity, and artificial intelligence.

Prior to joining Virginia Tech in 2010, he served as a researcher at the National Security Agency. Dr. Clancy received his BS in Computer Engineering from the Rose-Hulman Institute of Technology, MS in Electrical Engineering from the University of Illinois, and PhD in Computer Science from the University of Maryland. He is a Senior Member of the IEEE and has over 200 peer-reviewed technical publications and patents, is co-author to five books, and co-founder to four venture-backed startup companies.