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March, 2017

Virginia Tech tackles the DARPA Spectrum Collaboration Challenge


A team of researchers from Virginia Tech has been awarded a $2,000,000 grant from the Defense Advanced Research Projects Agency (DARPA) to participate in the Spectrum Collaboration Challenge. This grand challenge focuses on developing new techniques for collaboration between radios (using machine-learning) to overcome scarcity in the radio frequency spectrum. In this program, teams from around the world will compete to reimagine a new, more efficient wireless paradigm in which radio networks autonomously collaborate to dynamically determine how the spectrum should be used moment to moment.

The team, led by Mike Buehrer, professor of electrical and computer engineering (ECE) and director of Wireless @ Virginia Tech and Bob McGwier, chief scientist at the Hume Center for National Security and Technology, will participate in several rounds of competition through this program, developing unique technologies at each phase. Professors Jeff Reed and Jerry Park (both professors in ECE and well-known researchers in the area of spectrum sharing) are also part of the VT team.

The Virginia Tech team is also sponsored by Lockheed Martin's Advanced Technology Laboratories. The winning team from this multi-year effort could win as much as $3.5M.

Wireless @ Virginia Tech is one of the largest university-based wireless research groups in the United States. The primary mission of Wireless @ Virginia Tech is to develop a research environment that produces high caliber students who will become the future leaders in academia, industry, and government. Wireless @ Virginia Tech continues to take a leadership role in these efforts by conducting research into the opportunities and obstacles in newly emerging wireless technologies. Visit our website at for more information.

The Hume Center was founded in 2010 through an endowment from Ted and Karyn Hume. With support from Virginia Tech's College of Engineering and Institute for Critical Technologies and Applied Sciences (ICTAS), the Hume Center leads the university's education and research ecosystem for national security technologies, with an emphasis on the communication and computation challenges of the defense and intelligence communities. Approximately 150 undergraduate students and 50 graduate students participate in Hume Center programs each year, and most receive scholarships, fellowships, or research assistantships and are vectored toward careers working for the federal government or its industrial base. Visit for more information.


January, 2017

Wireless Students Awarded Travel Grants for the IEEE Wireless Communications and Networking Conference

Wireless@VT graduate students Chiranjib Saha, Mustafa Kishk, and Priyabrata Parida have been awarded competitive travel grants to attend the IEEE Wireless Communications and Networking Conference (WCNC) in San Francisco, CA, in March 2017. All three students are advised by Prof. Harpreet Dhillon. The IEEE WCNC is the world's premier wireless event that brings together industry professionals, academics, and individuals from government agencies and other institutions to exchange information and ideas on the advancement of wireless communications and networking technology. These travel grants are sponsored by the National Science Foundation and the IEEE Communications Society. Prof. Dhillon's group will have a significant presence in IEEE WCNC with the following seven papers:

- M. Afshang and H. S. Dhillon: k-coverage probability in a finite wireless network.
- M. Afshang and H. S. Dhillon: A New Clustered HetNet Model to Accurately Characterize User-Centric Small Cell Deployments.
- M. A. Kishk and H. S. Dhillon: Modeling and Analysis of Ambient RF Energy Harvesting in Networks with Secrecy Guard Zones.
- P. Parida and H. S. Dhillon: New Stochastic Geometry-based Analysis of Uplink Massive MIMO in Asymptotic Antenna Regime.
- S. Krishnan and H. S. Dhillon: Exact Characterization of Spatio-temporal Joint Coverage Probability in Cellular Networks.
- C. Saha and H. S. Dhillon: D2D Underlaid Cellular Networks with User Clusters: Load Balancing and Downlink Rate Analysis.
- P. Parida, H. S. Dhillon, and P. Nuggehalli: Stochastic Geometry Perspective of Unlicensed Operator in a CBRS System.


Wireless @ Virginia Tech Faculty Receives $1.4 Million NSF Research Grant


Dr. Dhillon and Dr. SaadDr. Walid Saad, the Stephen O. Lane Junior Faculty Fellow and assistant professor in electrical and computer engineering and Dr. Harpreet Dhillon, assistant professor of electrical and computer engineering has received a $1.4 million dollar National Science Foundation grant to develop a new planning framework for smart, connected, and sustainable communities also referred to as "smart cities", by developing new methodologies for the efficient use of big data analytics. Dr. Saad and Dr. Dhillon are collaborating with civil and environmental engineers from the University of Miami. Virginia Tech's share of the grant is $953,000. Read more...


Students Ali Talebzadeh and Aidin Ferdowsi Recipients of the 2017 Virginia Wireless Association Merit Fellowship

Ali TalebzadehAli Taleb Zadeh received his BS with honor in Electrical Engineering Communication Systems and Control Systems (double major in both communications and control theory) from the Iran University of Science and Technology and his MS in Communication Systems from University of Tehran. He is currently a PhD student at the Bradley Department of Electrical and Computer Engineering at Virginia Tech. He is working with Dr. Saad on research that is at the intersection of big data analysis, machine learning, control theory, and stochastic/robust optimization, with their applications in communications and networking.


Aidin Ferdowsi received his BS in Electrical Engineering from the University of Tehran, Iran. He is currently a Ph.D. student at the Bradley department of Electrical and Computer Engineering at Virginia. He is working with Dr. Saad on a project pertaining to creating a fundamental science for resilient smart cities. In particular, his research is at the intersection of cyber-physical systems, system security, and game theory.

December, 2016

27th Annual Wireless Symposium and Summer School News!

We are excited to announce that this year the 27th Annual Wireless Symposium & Summer School is moving to Arlington, VA! The 2017 Wireless Symposium will be hosted at the Virginia Tech Research Center on Glebe Road in Arlington, VA on May 16 - 17, 2017. Wireless @ Virginia Tech would also like to announce our keynote speakers, Ms. Ellen Purdy, with the Department of Defense and Mr. Paul Tilghman, with DARPA. Read more about our symposium, our new location, new format and registration fee schedule at our 2017 Symposium web page.

Dr. Walid Saad Elected to ComSoc Technical Committee

Dr. SaadDr. Walid Saad has been elected as the Vice-Chair of the Americas for the IEEE Communications Society (ComSoc) Technical Committee on Cognitive Networks. The goal of Technical Committee on Cognitive Networks (TCCN) is to provide a platform for its members and the cognitive networking research, development, policy making and standardization community in general, to interact and exchange technical ideas to identify major challenges and also drive solutions in the development of cognitive networking technologies. The term is effective January 1, 2017, for 2 years.


Wireless @ Virginia Tech Hosts "FCC Day"

On Monday, November 21, Wireless @ Virginia Tech hosted an all day workshop, dubbed "FCC Day", primarily for staff of the Federal Communications Commission at the Virginia Tech Research Center in Arlington. Five Wireless @ Virginia Tech faculty made presentations on elements of ongoing research projects, sponsored by the National Science Foundation and others, with implications for the future regulation of radio spectrum in the United States. Twenty-two FCC personnel attended the event, from four different FCC bureaus/offices, as well as a handful of representatives from other agencies and institutions.

Dr. ReedThe discussion was moderated by Prof. Jeff Reed and focused on four questions:

• What research aspects presented today are of most interest and use to the FCC?
• Where are there gaps in our research that we should attempt to address?
• How can we be more effective in technology transfer?
• How can we more actively engage with the FCC on an ongoing basis?



FCC photosIn addition to the faculty presentations, Julie Knapp, Chief of the FCC Office of Engineering & Technology gave a presentation on technical issues of interest to the FCC. The day also included some demonstrations by Wireless @ Virginia Tech graduate students, showing FCC personnel some of our work regarding vulnerabilities in LTE as well as some of the technology that we use to teach the next generation of wireless engineers about software defined radio. The day concluded with an hour-long discussion that summarized major technical issues and explored ways that Virginia Tech and the FCC can work together in the future.

Dr. Harpreet Dhillon Wins IEEE Communications Society’s Heinrich Hertz Award 

Harpreet Dhillon won the IEEE Communications Society’s Heinrich Hertz Award for Best Communications Letter for his paper titled “Downlink Rate Distribution in Heterogeneous Cellular Networks under Generalized Cell Selection” (IEEE Wireless Communications Letters, volume 3, no. 1, pp. 42-45, February 2014). The Heinrich Hertz Award is given to an outstanding manuscript published in any letter journal financially sponsored or co-sponsored by the IEEE Communications Society (ComSoc) during the previous three calendar years which opens new lines of research, envisions bold approaches to communication, formulates new problems to solve, and essentially enlarges the field of communications engineering. The selection of the award is based on the paper’s quality, exposition, novelty and impact. This is the fifth best paper award for Harpreet. His earlier best paper awards included the 2014 IEEE ComSoc Leonard G. Abraham Prize and the 2015 IEEE ComSoc Young Author best paper award. Congratulations to Dr. Dhillon!

Dr. Allen MacKenzie Appointed to the Commerce Spectrum Management Advisory Committee

Dr. MacKenzie Allen MacKenzie has been appointed to a two-year term on the Commerce Spectrum Management Advisory Committee (CSMAC) of the US Commerce Department’s National Telecommunications & Information Administration (NTIA). CSMAC advises the Assistant Secretary for Communications and Information at NTIA on a broad range of spectrum policy issues. The members are spectrum policy experts, appointed as "Special Government Employees," from outside the Federal government. Committee members offer expertise and perspective on reforms to enable new technologies and services, including reforms that expedite the American public's access to broadband services, public safety, and long-range spectrum planning.


Wireless @ Virginia Tech Postdoctoral Associate Selected to Attend Rising Starts Workshop in CMU

MehrnazMehrnaz Afshang, a postdoctoral associate advised by Prof. Harpreet S. Dhillon, was recently selected to attend the Rising Stars Workshop that recognizes the brightest women in electrical engineering and computer sciences (EECS). Rising Stars is an annual academic career workshop that brings together world's top sixty brightest female Ph.D. students, postdocs, and engineers/scientists, for scientific interactions and career-oriented discussions aimed at navigating the early stages of careers in academia. This year, the workshop was hosted and sponsored by Carnegie Mellon University's Department of Electrical and Computer Engineering, College of Engineering Center for Faculty Success, and the School of Computer Science, in collaboration with the MIT EECS department. This program was launched by MIT in 2012 to bring together the emerging women researches in the field of EECS.

Mehrnaz Afshang has been working in Dr. Dhillon’s group within Wireless @ Virginia Tech since January 2015; first as a visiting Ph.D. student and most recently as a postdoctoral associate. She received the B.E. degree in Electrical Engineering from Shiraz University of Technology, Iran, in 2011 and the Ph.D. degree from Nanyang Technological University, Singapore, in 2016. During her Ph.D., she was a recipient of the SINGA Fellowship, which partly supported her visit to Virginia Tech in 2015. Her research interests are in mathematical modeling and analysis of complex communication systems, such as the worldwide cellular communication system and emerging ad hoc communication networks. In particular, her work has focused on the analysis of small cell deployments and device-to-device (D2D) networking, which have both emerged as promising solutions to handle ever-increasing mobile data traffic in future 5G communication systems. In collaboration with Dr. Dhillon, she has been developing tools with foundation in stochastic geometry to expose fundamental design tradeoffs in these systems. Key technical innovations include sophisticated new models that allow to incorporate inter-point interactions in these emerging networks using ideas from Poisson cluster process and Poisson hole process.


November, 2016

Dr. Michel Buehrer and Dr. Jerry Park Members of the Class of 2017 IEEE Fellows

The Bradley Department of Electrical and Computer Engineering and Wireless @ Virginia Tech is pleased to announce that the IEEE Fellow Committee has selected two Wireless @ Virginia Tech faculty members, Dr. Michael Buehrer, Director of Wireless @ Virginia Tech and Dr Jung-Min "Jerry" Park, Associate Director for Affiliate Relations as well as the site director for the Virginia Tech Broadband Wireless Access and Applications (BWAC), for promotion to the level of IEEE Fellow.

The IEEE Grade of Fellow is conferred by the IEEE Board of Directors upon a person with an outstanding record of accomplishments in any of the IEEE fields of interest. The total number selected in any one year cannot exceed one-tenth of one- percent of the total voting membership. IEEE Fellow is the highest grade of membership and is recognized by the technical community as a prestigious honor and an important career achievement.

Dr. BuehrerR. Michael Buehrer, Professor and Director of Wireless @ Virginia Tech is being recognized for his contributions to wideband signal processing in communications and geolocation More specifically, his work had a direct impact on Second and Third Generation (2G and 3G) cellular phone systems during a critical time in the development of that technology. During his career (first at Bell Laboratories and later at Virginia Tech) Dr. Buehrer has risen to become a world-class researcher in wireless communications.  To date, he has published 300 journal and conference papers, many of which are widely cited.  He has over 5700 citations and an h-index of 39.   He holds 11 patents in the field of cellular communication networks.  Over the past 20 years he has made several fundamental contributions to the understanding and use of wireless communication systems and in particular has advanced the understanding of fundamental aspects of communications and geolocation systems that rely on wideband (e.g., spread spectrum or ultra-wideband) signals.  Among his accomplishments are techniques for increasing the capacity of Code Division Multiple Access (CDMA) cellular networks and improving localization performance in sensor networks.   He has received numerous awards for his research including multiple best paper awards.  He is also an active participant and organizer of IEEE conferences and workshops and has served as an editor for several IEEE journals, including IEEE Transactions on Communications, IEEE Transactions on Wireless Communications, IEEE Communications Letters, and IEEE Transactions on Signal Processing among others.

Dr. ParkJung-Min "Jerry" Park  is being recognized for his contributions to dynamic spectrum sharing, cognitive radio networks, and security issues. Dr. Park received his Ph.D. degree in Electrical and Computer Engineering from Purdue University, West Lafayette, IN, USA in 2003. He is currently the Site Director of a National Science Foundation (NSF) Industry-University Cooperative Research Center (I-UCRC) called Broadband Wireless Access & Applications Center (BWAC). Park is also an Executive Committee Member of the National Spectrum Consortium. His research interests include cognitive radio networks, dynamic spectrum sharing, networking, wireless security and privacy, and applied cryptography. Current or recent research sponsors include the NSF, National Institutes of Health (NIH), Defense Advanced Research Projects Agency (DARPA), Army Research Office (ARO), Office of Naval Research (ONR), and several industry sponsors. Park is a recipient of a 2014 Virginia Tech College of Engineering Faculty Fellow Award, a 2008 NSF Faculty Early Career Development (CAREER) Award, a 2008 Hoeber Excellence in Research Award, and a 1998 AT&T Leadership Award. He is currently serving on the editorial boards of the IEEE Transactions on Wireless Communications and the IEEE/KICS Journal of Communications and Networks.

The IEEE is the world’s leading professional association for advancing technology for humanity. Through its 400,000  plus members in 160 countries, the association is a leading authority on a wide variety of areas ranging from aerospace systems, computers and telecommunications to biomedical engineering, electric power and consumer electronics.

Dedicated to the advancement of technology, the IEEE publishes 30 percent of the world’s literature in the electrical and electronics engineering and computer science fields, and has developed more than 1300 active industry standards.  The association also sponsors or co-sponsors nearly 1700 international technical conferences each year.  If you would like to learn more about IEEE or the IEEE Fellow Program, please visit

October, 2016

Wireless @ Virginia Tech Faculty Member Dr. Walid Saad Releases New Book

Dr. Walid Saad has a new book titled Overlapping Coalition Formation Games in Wireless Communication Networks available through SpringerBriefs Press. "This brief introduces overlapping coalition formation games (OCF games), a novel mathematical framework from cooperative game theory that can be used to model, design and analyze cooperative scenarios in future wireless communication networks.

The concepts of OCF games are explained, and several algorithmic aspects are studied. In addition, several major application scenarios are discussed. These applications are drawn from a variety of fields that include radio resource allocation in dense wireless networks, cooperative spectrum sensing for cognitive radio networks, and resource management for crowd sourcing. For each application, the use of OCF games is discussed in detail in order to show how this framework can be used to solve relevant wireless networking problems.

Overlapping Coalition Formation Games in Wireless Communication Networks provides researchers, students and practitioners with a concise overview of existing works in this emerging area, exploring the relevant fundamental theories, key techniques, and significant applications."

Dr. Saad is an assistant professor and Steven O. Lane Junior Faculty Fellow with the Bradley Department of Electrical and Computer Engineering and a core faculty member of Wireless @ Virginia Tech. Co-authors of this book are T. Wang, L. Song, and Z. Han.



Wireless @ Virginia Tech Faculty Member Dr. Walid Saad Receives New Grant

Dr. Walid Saad, in collaboration with civil engineers from the University of Miami, received a two-year, $500,000 National Science Foundation grant to design new computational, mathematical, and simulation frameworks to protect the critical infrastructure of coastal cities against natural disasters. The project, supported by the Critical Resilient Interdependent Infrastructure Systems and Processes program, is titled "Collaborative Research: A Human-Centered Computational Framework for Urban and Community Design of Resilient Coastal Cities." Coastal cities are critical for the global economy, yet they are so frequently exposed to hurricanes, flooding, sea level rise, and other natural disasters. When infrastructure -- water, energy, sewer, and transportation systems as well as the built environment -- is compromised, the well-being of a city's residents is in jeopardy. Current emergency plans that spell out how coastal cities can endure and recover from natural disasters have no comprehensive strategy for infrastructure. Walid Saad and co-principle investigator Anamaria Bukvic from the Department of Geography are designing new frameworks to address these issues. Read more.

In addition, Dr. Saad's Ph. D. student, Omid Semiari, received an NSF Student Travel Grant award to attend IEEE GLOBECOM 2016. Wireless @ Virginia Tech faculty and students will be presenting papers and posters at Globecom. A list will be provided in the near future.

Wireless @ Virginia Tech Faculty Member Dr. Steve Ellingson Releases New Book

Dr. Steve EllingsonDr. Steve Ellingson, Associate Professor, has a new book on Radio Systems Engineering, released through Cambridge University Press. "Using a systems framework, this textbook provides a clear and comprehensive introduction to the performance, analysis and design of radio systems for students and practicing engineers. Presented within a consistent framework, the first part of the book describes the fundamentals of the subject: propagation, noise, antennas and modulation. The analysis and design of radios, including RF circuit design and signal processing, is covered in the second half of the book."

Dr. Ellingson received his PhD in Electrical Engineering from Ohio State University and is a core faculty member of Wireless @ Virginia Tech leading the research thrusts in RF Analysis and Technologies. Dr. Ellingson is also an avid amateur radio operator.

September, 2016

New Dealine for the Spectrum-ShaRC Challenge Registration

The new deadline is October 7, 2016 to submit your team registrations for the 2017 Spectrum ShaRC Challenge team registrations. We are also moving out the deadline to submit your code for the first round of competition to November 18. The remaining deadlines remain the same, round two is February 20, 2017 and the final round is April 7, 2017. Registration can be completed here. For more information on the Spectrum-ShaRC Challenge, please visit

Wireless @ VirginiaTech Student Sudeep Bhattarai Contributes in the Design and Deployment of the First Prototype ESC

Sudeep Bhattarai, a PhD student advised by Professor Jerry Park in the Department of Electrical and Computer Engineering, actively contributed in the design, development and deployment of the first prototype Environmental Sensing Capability (ESC) in San Francisco during his summer research at Google. This deployment is the first step towards enabling shared usage of 150 MHz of the radio spectrum in the 3.5 GHz band, also known as the Citizens Broadband Radio Service (CBRS) band.

The U.S. Federal Communications Commission (FCC) has recently opened the 3.5 GHz band for sharing between the Navy’s shipborne radars (incumbent users) and broadband communication systems (CBRS devices). A fundamental requirement for shared use of this band is that a dedicated network of sensors called ESCs must detect incumbent operations and alert the spectrum manager. The spectrum manager for the CBRS band is called the Spectrum Access System (SAS). SAS maintains orderly use of the band while protecting incumbents and coordinating spectrum use among CBRS devices. Upon receiving an alert from the ESC, the SAS reconfigures CBRS devices under its control to avoid harmful interference to the Navy radar.

Google, among others, has applied to the FCC to operate both a SAS and an ESC, and has been actively developing software and hardware capabilities to detect incumbent radars. The goal is to deploy a network of ESCs along the U.S. coastline and allow CBRS devices to operate in the coastal areas provided that they do not cause harmful interference to the incumbent users.

Wireless @ Virginia Tech's Dr. Mike Bueher and Former Student SaiDhiraj Amuru Published on IEEE Xplore Innovation Spotlight

Dr. Michael Buerer, Director of Wireless @ Virginia Tech and former student SaiDhiraj Amuru, and co-author Mihaela van der Schaar, professor of electrical engineering at UCLA, are featured on IEEE's Xplore Innovation Spotlight for their paper "Advertising Algorithms Could Be the Solution to Gaining Communication Network Intelligence". The paper can be located at

The IEEE Xplore Innovation Spotlight features articles on cutting-edge topics handpicked from the IEEE Xplore digital library of over 3 million technical documents. Research found in IEEE Xplore solves critical industry issues, keeps technology professionals at top organizations up to date, and helps develop the technologies of tomorrow.


August, 2016

Spectrum Sharing Radio Challenge 2 (Spectrum-ShaRC 2) Has Begun!

Spectrum ShaRC 2The Spectrum-ShaRC 2 Radio Challenge will begin to accept registrations on September 6, 2016. Registration forms are available now through their website at, and are due September 20, 2016. This year we have made several changes. There will be 3 phases instead of 4. The final competition is one day, April 7, 2017. The challenge will start earlier and end earlier to avoid conflicts with students who may have summer jobs or internships. The new Rules and Regulations are also now available. The first place prize is $5,000; second place is $3,000, and third place is $1,500. 4th place is an Ettus Research radio front end valued at $750. This year the limit is 10 students per team, and a limit of 18 teams in total; 15 teams will be US based and 3 teams will be international. Registration opens on September 6, 2016 and closes on September 20, 2016. Please visit their website for complete information.

July, 2016

Wireless @ Virginia Tech Receives $2.5 Million in Grants

NSF has awarded Wireless @ Virginia Tech $2.5 million in grants to support several research projects that seek to address critical issues concerning emerging wireless communication networks and technology in support of the new White House Advanced Wireless Initiative.

"The five research projects awarded to Virginia Tech are intended to propel the technological revolution of wireless for decades ahead, from spectrum management to the Internet of Things,” said NSF program director Thyaga Nandagopal. “The White House initiative aims to deploy and use four city-scale testing platforms for advanced wireless research over the next decade with Platforms for Advanced Wireless Research, a program designed to develop wireless research platforms conceived by the U.S. academic and industrial wireless research community."


June, 2016

Virginia Tech Student Researchers Make the News on Smart Grid Security

Dr. Saad and Anibal SanjabA recent report on Smart Grid Security co-authored by Virginia Tech student Anibal Sanjab was covered in the news on The report was the first comprehensive report on smart grid scurity released by educational researchers at the the Network Science, Wireless and Security lab at Virginia Tech. Other co-authors include Dr. Walid Saad, Assistant Professor, Wireless @ Virginia Tech and Anibal Sanjab's advisor; Dr. Ismail Guvenc, and student Arif Sarwat, Dept. of Electrial and Computer Engineering, Florida International University, Miami, FL. and Saroj Biswas, Dept. of Electrical and Computer Engineering, Temple University, Philadelphia, PA. The full report is available here. Congratulations to Anibal and Dr. Saad.

ASEE Workshop on June 26, 2017

Virginia Tech is organizing a workshop at ASEE 2016 in New Orleans, LA, on Visualization and Gamification for Radio Engineering Education, to be held from 1-4 p.m. on Sunday, June 26. The workshop will present intermediate results of an NSF IUSE grant for enhancing Undergraduate STEM Education, which we described in a paper at the ASEE conference in Seattle last year (

We plan to demonstrate interactive educational and visualization tools that we have developed for experimental learning, solicit feedback and suggestions, discuss synergies and the possible applications of our tools to serve the needs of other schools. The abstract can be found at

Registration is $25 in advance and $35 on site.

Shankar Krishnan Successfully Defends His Master's Thesis

Dr. Dhillon and ShankarCongratulations to Shankar Krishnan for successfully defending his thesis "Spatio-Temporal Correlation in the Performance of Cache-Enabled Cellular Networks". Shankar will begin his new job as a Systems Integration & Test Engineer at Qualcomm R&D, San Diego in July. Shankar joined Virginia Tech in Fall 2014 and did his Masters in Electrical Engineering specializing in wireless communication. His Master's thesis advisor is Dr. Harpreet Dhillon. Shankar's thesis abstract is listed below. This thesis investigates the fundamental problem of studying spatio-temporal correlation in cellular networks and develops a new analytical framework to characterize the network performance in terms of joint coverage probability and interference correlation coefficient. While developing models and analytical expressions for studying the two extreme cases of spatio-temporal correlation - i) uncorrelated scenario and ii) fully correlated scenario are easier, studying the intermediate case is non-trivial. Using tools from stochastic geometry, we study this non-trivial correlation in cellular networks to characterize the joint network performance at any two spatial locations. After providing generic results for traditional cellular networks, we study two applications exploiting spatio-temporal correlation in cache-enabled cellular networks. First, we determine the optimal cache content to be stored in the cache of a small cell network that maximizes the hit probability and minimizes the reception energy for the two extreme cases of correlation. Second, we look at a distributed caching scenario in user devices and show that spatio-temporal correlation can be exploited to improve the network performance significantly.


May, 2016

Dr. Carl Dietrich Receives NSF Travel Grant for the Spectrum Sharing Radio Challenge (Spectrum-ShaRC)

Dr. Carl Dietrich has received a National Science Foundation travel grant to help offset the travel expenses for the students participating in the Spectrum Sharing Radio Challenge (Spectrum-ShaRC) that is taking place on June 1 - 2, 2016 at the 26th Annual Wireless Symposium and Summer School. Out of the original 18 teams that submitted code in the first round of the challenge, we are now down to the final six teams from the United States and Greece that are competing for the top 3 cash prizes, 1st place is $5,000, 2nd place is $3,000 and third place is $1,500. For more information on the Spectrum Sharing Radio Challenge, please visit For more information on our 26th Annual Symposium & Summer School, please visit our agenda page.

Amos Ajo Successfully Defends His Master's Thesis

Amos AjoCongratulations to Amos Ajo for successfully defending his thesis "Design and Implementation of a Constant Envelope OFDM Waveform in a Software Defined Radio Platform". Amos will begin his new job with the Naval Research Laboratory in June while he continues his education as a Ph.D. student with the Wireless @ Virginia Tech research group. Amos was a 2013 Research Experience for Undergraduates participant with Wireless @ Virginia Tech. Amo's advisor is Dr. Carl Dietrich. His thesis abstract is listed below.


This thesis examines the high peak-to-average-power ratio (PAPR) problem of OFDM and other spectrally-efficient multicarrier modulation schemes, specifically their stringent requirements for highly linear, power-inefficient amplification. The thesis then presents a most intriguing answer to the PAPR-problem in the form of a constant-envelope OFDM (CE-OFDM) waveform, a waveform which employs phase modulation to transform the high-PAPR OFDM signal into a constant envelope signal, like FSK or GMSK, which can be amplified with non-linear power amplifiers at near saturation levels of efficiency. A brief analytical description of CE-OFDM and its suboptimal receiver architecture is provided in order to define and analyze the key parameters of the waveform and their performance impacts. The primary contribution of this thesis is a highly tunable software-defined radio (SDR) implementation of the waveform which enables rapid-prototyping and testing of CE-OFDM systems. The digital baseband processing of the waveform is executed on a general purpose processor (GPP) in the Linux Ubuntu 14.04 operating system, and programmed using the GNU Radio SDR software framework with a mixture of Python and C++ routines. A detailed description of the software implementation is provided, and baseband simulations of the SDR CE-OFDM receiver in additive white Gaussian noise (AWGN) validate the performance of the implemented signal processing. A fully-functional CE-OFDM radio system is proposed in which GPPs executing the software defined transmitter and receiver routines are interfaced with Ettus Universal Software Radio Peripheral (USRP) transceiver front ends. A software ‘test bench’ is created to enable rapid configuration and testing of the CE-OFDM waveform over all permutations of its parameters, over both simulated and physical RF channels, to draw deeper insights into the characteristics of the waveform and the necessary design considerations and improvements for further development and deployment of CE-OFDM systems.

Amos's research interests for the future are: Software Defined Radio, FPGA Implementation of PHY layer, PAPR Reduction in OFDM systems, applications of constant-envelope multicarrier waveforms in next-generation wireless protocols.


Eric Sollenberger Successfully Defends His Master's Thesis

Eric SollenbergerCongratulations To Eric Sollenberger for successfully defending his thesis "Iterative Leakage-Based Precoding for Multiuser-MIMO Systems" (abstract below). Eric will begin his new job as a systems engineer for Qualcomm in Boulder, Colorado, June 27, 2016. You can follow Eric on LinkedIn. Eric's advisor was Dr. Michael Buehrer.


Abstract: This thesis investigates the application of an iterative leakage-based precoding algorithm to practical multiuser-MIMO systems. We consider the effect of practical impairments including imperfect channel state information, transmit antenna correlation, and time-varying channels. Solutions are derived which improve performance of the algorithm with imperfect channel state information at the transmitter by leveraging knowledge of the second-order statistics of the error. From this work we draw a number of conclusions on how imperfect channel state information may impact the system design including the importance of interference suppression at the receiver and the selection of the number of co-scheduled users. We also demonstrate an efficient approach to improve the convergence of the algorithm when using interference-rejection-combining receivers. Finally, we conduct simulations of an LTE-A system employing the improved algorithm to show its utility for modern communication systems.

April, 2016

Dr. Harpreet Dhillon Wins IEEE Communications Society’s Heinrich Hertz Award 

Harpreet Dhillon won the IEEE Communications Society’s Heinrich Hertz Award for Best Communications Letter for his paper titled “Downlink Rate Distribution in Heterogeneous Cellular Networks under Generalized Cell Selection” (IEEE Wireless Communications Letters, volume 3, no. 1, pp. 42-45, February 2014). The Heinrich Hertz Award is given to an outstanding manuscript published in any letter journal financially sponsored or co-sponsored by the IEEE Communications Society (ComSoc) during the previous three calendar years which opens new lines of research, envisions bold approaches to communication, formulates new problems to solve, and essentially enlarges the field of communications engineering. The selection of the award is based on the paper’s quality, exposition, novelty and impact. This is the fifth best paper award for Harpreet. His earlier best paper awards included the 2014 IEEE ComSoc Leonard G. Abraham Prize and the 2015 IEEE ComSoc Young Author best paper award. Congratulations to Dr. Dhillon!

Wireless @ VT Researchers Win Best Paper Award at IEEE WCNC IWSS

Dr. Dietrich, Mo Kim, Junsung ChoiThe award, presented at the 2nd IEEE WCNC 2016 International Workshop on Smart Spectrum in Doha, Qatar, recognized the following paper: Seungmo Kim, Junsung Choi, and Carl B. Dietrich, “Coexistence between OFDM and Pulsed Radars in The 3.5 GHz Band with Imperfect Sensing,” IEEE WCNC 2016, Doha, Qatar, 3-6 April 2016.


Mo Kim

Mr. Kim, shown accepting the award was awarded a travel grant to WCNC, where he also presented a sole-authored paper, “A TDMA-Based MAC between Gateway and Devices in M2M Networks” at the Green and Sustainable 5G Wireless Networks (GRASNET) workshop.


Dr. Dhillon is organizing workshop on Green Networks in WiOpt 2016

Dr. DhillonTogether with Prof. Kaibin Huang of University of Hong Kong and Prof. Aylin Yener of Penn State University, Dr. Harpreet Dhillon is organizing a workshop on Green Networks in WiOpt 2016. Wireless networks, especially radio access networks, are a major consumer of electricity worldwide, thus contributing significantly to global warming. While the exact numbers may vary across sources, it is generally agreed that this energy consumption amounts to a few percent of the total consumption worldwide. Despite improvements in energy efficiency, the total energy consumption by wireless networks is escalating due to rapid densification and expansion of radio access networks, which is necessary to cope with the exponential growth of mobile Internet traffic. As a result, the sustainability of the growth of mobile Internet applications and services is under threat. In the past decade, the fast expanding carbon footprint of wireless networks has motivated researchers to conduct active research on energy efficient and sustainable networks, which is generally referred to as "green networks" and is the theme of this workshop. The workshop is co-located with the 14th International Symposium on Modeling and Optimization in Mobile, Ad Hoc and Wireless Networks (WiOpt) to be held in Arizona State University, Tempe, Arizona, USA, during May 2016.

Chiranjib Saha Receives Inaugural Wireless Fellowship

SahaThrough a contribution from the Virginia Wireless Association, Wireless @ Virginia Tech has established a Merit Fellowship starting Fall 2015. The first recipient of this fellowship is Chiranjib Saha, a Wireless @ VT Ph.D. student advised by Dr. Harpreet Dhillon. Saha joined Virginia Tech in Fall 2015 after completing his B.E. degree in Electronics and Telecommunication Engineering from Jadavpur University, India. He is working with Dr. Dhillon on developing new models for the analysis of heterogeneous cellular networks using tools from stochastic geometry. His research during the first semester focused on incorporating non-uniform user distributions in the state-of-the-art stochastic geometry models, which may also be correlated with the BS distributions. The preliminary results will be presented at the IEEE International Conference on Communications (ICC) 2016 in Kuala Lumpur, Malaysia.


March, 2016

Dr. Yaling Yang Receives the College of Engineering Faculty Fellow's Award

Dr. YangDr. Yaling Yang has been awarded one of the College of Engineering Faculty Fellow's award. This prestigious honor includes a $15,000 monetary award that will support Dr. Yang's research for the next three years. The awards ceremony is scheduled for May 03, 2016 from 5:00 - 7:00 pm at the Inn at Virginia Tech. Congratulations Dr. Yang!



Dr. Walid Saad Receives Outstanding New Assistant Professor Award

Dr. SaadWireless @ Virginia Tech is pleased to announce that Dr. Walid Saad has received the College of Engineering Dean’s Award for Outstanding New Assistant Professor this year. The award ceremony will take place on May 03, 2016, 5:00-7:00 pm at the Inn at Virginia Tech. Congratulations, Dr. Saad!



Congratulations to Ph.D. Student Marc Lichtman on his Recent Publications

Marc LichtmanPh.D. student Marc Lichtman has had two papers published by the IEEE. The first paper was published in February, 2016 in IEEE Security and Privacy titled "A Communications Jamming Taxonomy" co-authored by Jeffrey D. Poston; SaiDhiraj Amuru; Chowdhury Shahriar; T. Charles Clancy; R. Michael Buehrer; and Jeffrey H. Reed. The second paper is titled "Antifragile Communications" in the IEE Systems Journal. Congratulations to Marc! Marc's advisor is Dr. Jeffrey Reed.



January, 2016

 Papers from Dr. Jerry Park’s Group Featured in IEEE Communications Society (ComSoc) Best Readings in Cognitive Radio (CR)

Dr. ParkThe IEEE Communications Society (ComSoc) has selected two papers from Dr. Jerry Park’s ARIAS (Advanced Research in Information Assurance and Security) research group for inclusion in the ComSoc’s Best Readings in Cognitive Radio (CR) list. The first paper entitled “Defense against primary user emulation attacks in cognitive radio,” written by R. Chen, J. Park and J. H. Reed was originally published in January 2008 in the IEEE Journal on Selected Areas in Communications. This paper systematically shows that “primary user emulation” attacks can result in severe interference and significantly reduce spectrum utilization. To address the problem, the authors propose a transmitter verification scheme that is able to identify whether a signal is being transmitted from primary users or not by using an estimate of the transmitter’s location and the characteristics of the signal itself.

The second paper entitled “Toward secure distributed spectrum sensing in cognitive radio networks,” was coauthored by R. Chen, J. Park, Y. T. Hou, and J. H. Reed, and was originally published in April, 2008 in the IEEE Communications Magazine. This paper introduced pioneering work on mitigating security threats such as incumbent emulation and spectrum sensing data falsification threats in cognitive radio networks. The paper also described countermeasures for addressing those threats. The IEEE ComSoc’s Best Readings in Cognitive Radio (CR) list is a recommended reading list of books, articles and papers on Cognitive Radio Communications and Networking that are of interest to the IEEE ComSoc readership. IEEE ComSoc’s Best Readings in Cognitive Radio (CR) list is available here.


Jerry Park Awarded Major NSF Grant To Address Dynamic Exclusion Zones in Radio Spectrum

Dr. ParkThe Federal Communications Commission is opening up bands of spectrum that were previously restricted to a few priority users, including the military. Virginia Tech College of Engineering professor Jung-Min “Jerry” Park is leading a $730,000 National Science Foundation grant collaboration with William Lehr from the Massachusetts Institute of Technology, to find ways to make this transition as smooth as possible. The FCC’s plans to provide incumbent users with a wide, insulating boundary, often called an exclusion zone, separating them from new users. In this type of environment, incumbent users have first dibs on the spectrum, and the secondary users can access what’s left over. 

Park, of the Bradley Department of Electrical and Computer Engineering, and his collaborators intend to develop a new strategy supporting blueprints for flexible exclusion zones, or an adjustable boundary, that can respond dynamically to the incumbent protection requirements and the interference environment. In this way, incumbent users will still have safe, clear access to their frequencies, but secondary users will be able to make efficient use of the spectrum when it’s free. Read more

Dr. Michael Buehrer, Director of Wireless @ Virginia Tech, and Dr. Harpreet Dhillon Co-Chair at GLOBECOM, 2015

Dr. Buehrer and DhillonDr. Michael Buehrer and Dr. Harpeet Dhillon co-chaired a workshop on geolocation at the recent IEEE GLOBECOM 2015 Workshop on Localization for Indoor, Outdoors, and Emerging Networks (LION) on December 6, 2015. Drs. Buehrer and Dhillon along with Ph.D student Javier Schloemann, also presented a paper as part of that workshop titled "Effect of Collaboration on Localizability in Range-Based Localization Systems". For more information on the GLOBECOM conference please visit




Jerry Park Elected to Serve on Executive Committee of the National Spectrum Consortium

Dr. ParkJerry Park, professor in the Department of Electrical and Computer Engineering, has been elected to a three-year term serving as an academia representative on the Executive Committee of the National Spectrum Consortium (NSC).

The NSC is a non-profit organization formed in 2014, whose mission is to improve collaboration between industry, government, and academia to advance research and development of technologies to better use the electromagnetic spectrum. The Executive Committee is the NSC leadership and governance body authorized to oversee the activities of the Consortium.

New wireless technologies and applications have skyrocketed the demand for spectrum, which is a finite natural resource. The ability to efficiently manage that resource is critical to the national economy and the military’s ability to secure wireless communications. The NSC has signed a $1.25 billion, five-year contract with the Office of the Deputy Assistant Secretary of Defense, Emerging Capabilities and Prototyping Office, to develop a research and development program designed to maximize utilization of the spectrum by broadening the commercial use of available spectrum while protecting the U.S. military’s access to select radio frequencies.

As an Executive Committee member of the NSC, Park will work with the other members of the committee to develop policy to govern the development of research and business opportunities that will meet the Consortium’s goal. Over $500 million dollars will be available to help Consortium members finance and advance the research and development, and transfer the resulting technology to the marketplace.

Jerry Park is the associate director for affiliate relations of Wireless @ Virginia Tech, a research group within the Bradley Department of Electrical and Computer Engineering, dedicated to the development of wireless technology, as well as the site director of the Broadband Wireless Access and Applications Center (BWAC), an NSF-funded Industry-University Cooperative Research Center (I-UCRC) whose primary mission is to advance research collaboration between researchers in academia and industry partners and promote the transfer of technology from universities to the industry. ECE Link