summary of projects - virginia tech · summary of projects may 2011 ... • runs the cognitive...

Summary of Projects

May 2011

Wireless @ Virginia TechVirginia Polytechnic Institute and State University

432 Durham HallMail Code 0350

Blacksburg, VA 24061Tel: 540-231-2958

http://www.wireless.vt.edu

Anonoloy

Objective /Goals

Impacts Applications

Highlights

• Create statistically verifiable algorithm to tessellate a reporting area into k-anonomyous regions

• Enable high-granularity tessellations if the population is dense enough to support k-anonymity at that granularity

• Allows locational privacy to be protected in numerous systems that require sensor location reporting

• Enables release of datasets containing locational information for use in multiple other types of research

• Developed algorithm uses no a priori data

• Developed algorithm can dynamically re-tessellate as population distribution changes

• Developed algorithm can handle continuous locations, while prior research can only handle a discrete set of location points

Hamilton Turner, Jules White

Developing algorithms to preserve locationalanonymity in any type of field-based data reporting, such as participatory or opportunistic sensing

Antennas for High-Temperature Sensor Measurements

High-Temperture Gas-Flow SensorOperational and Performance Capabilities - SummaryDesign and develop operational antennas for use in a high-temperature sensor environment

Technical Approach:

• Task 1: Design antenna for broadband environment testing to quantify environment gases

• Task 2: Evaluate environment under operation for transmission bands through the gases => Basis for narrowband sensor and antenna design to sense the environment temperature.

• Task 3: Develop measurement and calibration process for measuring temperature sensor using antennas at the design frequency. Evaluate patterns, efficiency, impedance, and multipath performance

• Task 4: Demonstrate sensor system

To Be Developed:• Analysis of performance of selected designs• Environment characteristics• Narrowband antennas to withstand environment at design frequency and sensitive to temperature sensor

Corporate Information:Virginia Tech, Wireless@VT, VA Tech Antenna GroupDr. William A. Davis302 Whittemore Hall (0111), Blacksburg, VA, 24061Tel: 540-231-6307; Fax: 540-231-3362; E-mail: [email protected]://antenna.ece.vt.edu/

• Transmission frequency bands• Antenna performance: VSWR, Pattern, Efficiency• Antenna survivability in the high-temp environment (copper will melt)• Demonstrate operation of the sensor system with corporate partner

Aperiodic Antenna Arrays Benjamin Baggett (Adviser: Tim Pratt)

Objective /Goals

Impacts ApplicationsFuture Work

Highlights

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Max SLL = -16.24 dBMax Gain = -1.62 dBHPBW = 1.00 degPointing Error = 0.00 degOper. Freq = 10.50 GHz

• Utilize aperiodic element spacing in antenna arrays

• Wide bandwidth capabilities• Electronic scanning without grating lobes• Reduced number of antenna elements • Maintain comparable far-field pattern

performance to periodic reference array

• Use optimization algorithm to optimize antenna element locations

• Particle Swarm Optimization (PSO)• Array thinned to 77% of original periodic array

• Axial-mode helix used as antenna element

• Scanning ability to ±30°• 1.5-to-1 bandwidth• Grating lobe reduced by over 8.5 dB• Directivity reduced by only 1.0 dB

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Max SLL = -7.51 dBMax Gain = -1.62 dBHPBW = 1.00 degPointing Error = 0.00 degOper. Freq = 10.50 GHz

Wideband periodic array scanned to +30°

Wideband aperiodicarray scanned to +30°

• Thinning of array elements significantly reduces array cost

• Aperiodicity allows high bandwidth without introduction of grating lobes

• Very useful for any applications requiring high bandwidth arrays

• Theory can be expanded to 2-dimensional arrays

Capacity of Wireless NetworksM. Marathe, G. Pei, A. Vullikanti, VBI, CS and ECE

Objective /Goals

Impacts Highlights

Sponsors: NSF

Characterizing the rate region of a given network and traffic matrixNetwork planning and survivability analysis: estimating potential loss in capacity, and resource allocation to optimize capacity

Develop efficient algorithms for characterizing rate region and quantifying tradeoffs between different objectives, e.g., delays and capacity

Cross-layer optimizationDifferent interference models

Distributed algorithms with low control overhead

Throughput vs long term fairness

Algorithmic framework based on LP framework for approximating rate region

General techniques: linearization and inductive ordering for capturing physical and scheduling constraints

Rigorously provable approximation guarantees for many interference models, including physical interference model based on SINR constraintsCan incorporate a variety of constraints, e.g., power, fairnessDelay throughput tradeoffs with bounds independent of network size

Published in [Pei et al., IEEE INFOCOM 2011], [Chafekar et al., IEEE INFOCOM 2008], [Kumar et al., ACM SIGMETRICS 2005]

Classification of DSA Channel Selection StrategiesTamal Bose, Matthew Rebholz

Objective /Goals

Impacts Highlights

Sponsor: Rockwell Collins Advanced Technology Center

• Further the relationship between Rockwell Collins and Virginia Tech•Develop a Dynamic Spectrum Access (DSA) network simulator•Use the network simulator to analyze different cognitive radio behaviors•Improve the usefulness of different classification techniques to track radios across channels

• Developed and continuously improving the Universal DSA Network Simulator (UDNS)

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• Increased accuracy of radio tracking using naïve Bayesian classification to nearly 80 % with improved scalability

• UDNS will be included in Rockwell Collin’s cognitive engine architecture when completed in July 2011•Potential military and civilian applications •Interface with spectrum sensors and cognitive engines

ClearMobileAdam Antonioli, Steven Byle, Avinash Sridhar, Hamilton Turner, Jules White

Objective /Goals

Impacts Applications

Highlights

• Allow non-programmers to create large-scale data collection applications through a web portal

• Provide storage and visualization of large-scale collected sensor data sets

• Fully usable system creates potential for complex user trials and comparisons to other systems

• Well-defined server API enables expansion to other client systems, such as WP7

• Scalable cloud-based data collection

• Ability to target data collection to specific regions and for user phones to dynamically discover new data collection applications

• Web-based portal to allow researchers to design and deploy data collection apps

Team Lead: Hamilton Turner

Development a framework for rapidly creating applications to collect sensor and other data from users’ smartphones.

NSF-REU: Cognitive CommunicationsTamal Bose, Tonya Smith-Jackson

Objective /Goals

Research Areas

Highlight

To gain hands-on experience in cognitive radios, wireless networking, and their applications;

To develop general research skills and teamwork skills;

To expose the students to the intellectual excitement in emerging wireless communications technology;

To promote creative and independent thinking, a sense of confidence, team spirit, and an appreciation for the potential of interdisciplinary collaboration in creating new knowledge;

To excite the students to pursue graduate studies.

An opportunity for undergraduate students from around the country to participate in the ongoing research activities of Wireless@VT.

Theory and application of algorithms and artificial intelligence for wireless communications;

Signal Processing for software defined radio and cognitive radio communications;

Software framework (OSSIE/GNUradio) and its applications for software defined radio and cognitive radio communications;

Algorithms implementation using a cognitive radio network testbed (VT-CORNET)

Applications of usability/human factors principles, and sociotechnical systems frameworks to cognitive engine and interface design, development, and evaluation.

Sponsor: NSF

Period of Performance: 2009-2012

Cognitive Electronic WarfareM. LaPan, C. Clancy

Sponsor: NRL

Objective /Goals

Applications and Impacts Highlights

Develop highly efficient jamming techniques, as measured by average radiated power

Develop jamming techniques that can learn and track target waveforms

Investigate how learning can be used against intelligent radios, such as cognitive radios using dynamic spectrum access

Apply game theory to optimal jammer design for adaptive waveforms

Investigate non-traditional jamming attacks (targeting implementations rather than protocols)

Support the next generation of electronic warfareBridge the gap between electronic attacks and

computer network attacksFeed future electronic attack platforms with

advanced jamming capabilitiesDevelop attacks that can permanently disable target

devices, rather than simply degrade them temporarily

Cognitive Radar for Spectrum CoexistenceS. Sodagari, M. Marcus, C. Clancy

Sponsor: ICTAS

Objective /Goals


Develop techniques where a radar platform can use its frequency agility and sensing capabilities to steer around commercial communications networks

Develop communications systems that can take cues from radar platforms to operate in the same band with interference tolerance

Apply these approaches to the Navy’s Aegis AN/SPY-1 platform and address key interference issues with commercial WiMAX platforms

Allows for major spectrum savings for DOD if radar and comms can share the same spectrum

Provides greater resolution to radar platforms by allowing them to leverage existing comms bands

Provides added capacity to comms networks by allowing them to operate in the low-duty-cycle radar bands

Help the DOD solve spectrum crunch issues associated with implementation of the National Broadband Plan

Cognitive Radio Network Testbed (CORNET)PIs: Jeff Reed and Tamal Bose

Objectives/Goals

ImpactsHighlights

• Develop and build an open heterogeneous cognitive radio network testbed for the development, testing, and evaluation of cognitive engine techniques and cognitive radio network applications.

The ICTAS building with the testbed nodes in red

Period of performance:September 2009 – December 2010

Sponsor:Office of Naval Research

• 48 nodes in a modern engineering building• Node hardware:

• Dedicated server for each node• USRP 2• Custom RF DB (100MHz- 4GHz)

• Complete control of the PHY and MAC layer • Remotely accessible• Runs the Cognitive Radio Open Source System(CROSS)

• Enables researchers at Virginia Tech and partner institutions to evaluate independently developed cognitive radio engines, sensing techniques, applications, protocols, performance metrics, and algorithms in a real world wireless environment, in contrast to a computer simulation or single node-to-single node environment• Offers a unique educational environment using real radios

NSF-CCLI: Cognitive Radio Vertical IntegrationTamal Bose, Tonya Smith-Jackson, Carl Dietrich

Objective /Goals

Impacts Highlights

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Introduce Cognitive/Software Radio concepts to Undergraduates.

Move current Graduate level SDR course into the undergraduate curriculum.

Vertically integrate CR/SDR concepts into several undergraduate courses, starting Freshman year.

Adapt and expand current curriculum to better prepare graduates for modern communications topics.

Develop lab activities and workshops to provide hands-on learning.

Development of undergraduate lab activities at VT and NSU

Digital Communications: SDR Using OSSIE Analog AM/FM analysisDigital PSK/QAM/ASK analysis

Engineering Exploration: Communications Intro using Matlab

Intro to digital modulation and BERPulse shaping and channel filters

Trial labs run during Fall semester 2010Vertical integration self assessment

Preliminary integration of lab activities into the undergraduate curriculum provides a basis for the continued vertical integration of advanced communications topics into the undergraduate curriculum.

Cooperation with NSU facilitates a multi-institutional plan for implementing and analyzing amendments to the curriculum across a diverse cross section of students.

Sponsor: NSF

Period of Performance:2009-2011

Collaborative Position LocationBenton Thompson and Dr. R. Michael Buehrer

Objective /Goals

Impacts and ApplicationsHighlights

Sponsored by the Harry Lynde Bradley Fellowship

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Large error Minimal error • Accurately locate all nodes given noisy range estimates between them.

• Improve upon the inexpensive and distributed parallel projection method (PPM).

• Resolve flip ambiguities and large errors using reflected location estimates.

• Exceed performance of existing solvers.

• Characterization of non-collaborative case reveals multiple minima as main source of error.

• Reflected PPM nearly guarantees optimal solution in non-collaborative case.

• Collaborative localization improved by reflected method; more gains to be achieved.

• Wireless network localization made possible with an accurate, distributed, and inexpensive algorithm.

• Applications include• Geotagging scattered sensors• Creating a real-time map of military

personnel locations• Indoor building layout mapping

Cross-Layer Optimization for Video Transport in Wireless Ad Hoc Networks

Investigators: Thomas Hou, Hanif D. Sherali

Objectives

• Support video communications over dynamic ad hoc networks

• Mitigate the impact of network dynamics (topology change, link/node failure) on video quality

• Optimize video quality under network resource constraints

Impacts

• Numerous applications for public safety, military, and general public

• Serves a critical need in ad hoc networking community

• New educational materials for classroom and research opportunities for students

Highlights

• Exploit multiple description video and multipath routing

• Cross-layer optimization with application layer performance objective

• Design of distributed algorithms and protocols

• Testbed prototyping and validation

Graphic or Photo

Period of Performance: 8/2009 – 8/2012Sponsor: NSF

Cryptographic API and Subsystem SimulatorJ. Reed, J. Park, T. Newman, and B. Brisbon

Objectives/Goals

ImpactsHighlights

• Develop a cryptographic API and the security component adapters that interface with a cryptographic subsystem

• Crypto API and adapters are based on the Security Supplement of the SCA 3.0 specification

• Develop a cryptographic subsystem simulator• Create a waveform demonstration using the developed componentsExample block diagram of an OSSIE system using the

Security Adapter and Crypto Subsystem Simulator.

Period of performance:Sep. 20, 2008 – Sep. 20, 2009

Sponsor:SCA Technica

• The cryptographic adapters that we developed in this project have a multitude of uses. Targeted specifically for the OSSIE software radio framework, the security adapters can be used for COMSEC, TRANSEC, and simply encrypting files on the file system. • We have followed the specification as laid out by the SCA 3.0 Security Supplement, and while not officially supported by JTRS, it provides a solid baseline for security adapter frameworks.

• As a result of this project, a security adapter component and several security enhanced components were added to the library of OSSIE components. As a result, many of the current waveforms can have secure alternatives. Along with the OSSIE components, a software based cryptographic subsystem simulator, while not high performance, can assist academic developers and even be used in classrooms for SDR education and security education.

Dynamic Spectrum Access Security M. Whitaker, C. ClancySponsor: Pentagon CIO

Objective /Goals


Military is deploying Dynamic Spectrum Access (DSA) tactical radios without fully understanding the impact of recently-discovered attacks

Virginia Tech developed a vulnerability assessment and spectrum simulation tool to inform policy decisions

Virginia Tech has authored DOD’s policy for tactical radios using DSA technology

Ongoing research seeks to further protect DSA systems from jamming attacks

Quantified risk and developed policy that has allowed DSA radios to be fielded

Proof of concept implementation & demonstration done with Shared

Spectrum Company

Proof of concept implementation & demonstration done with Shared

Spectrum Company

Dynamic Spectrum: Models, Allocation and UsageMadhav Marathe, Achla Marathe, Anil Vullikanti,VBI, CS and Agriculture and Applied Economics

Objective /Goals

Impacts HighlightsSponsors: NSF, DTRA

Significant white spaces in many spectrum bandsCognitive networks for dynamic spectrum accessAuctioning of spectrum bands in primary and secondary markets

Spatio-temporal model of spectrum demandModel should be able to account for behavioral changes Understand the impact of new disruptive technologies (tablets, iphones)

Understand the impact of different kinds of market mechanisms for efficient spectrum use and allocation

Spectrum demand in Portland, 1 pm

First principles modeling framework for modeling time-varying spectrum demand in large urban regions

Depends on underlying cellular infrastructure, user mobility, social network, Models effect of behavioral changes on spectrum demandIntegrates a number of public and commercial data setsAgent based framework for studying different market mechanisms

Can study impact of behavioral changes and homophilies in call patternsSpeculators and secondary market has significant impact on market efficiencyTruthful auction mechanisms such as Ausubel’s ascending auction can be applied for efficient market clearing.

Published in DySPAN’10,11 CRIS’10

Efficient Jammers Using a Cognitive Radio NetworkTamal Bose and Jeffrey H. Reed

Objective /Goals

ResultsHighlights

Proposed Cognitive Jammer

Sponsored by: Center for Advanced Engineering and Research

Automatic modulation classifier (AMC) that is robust to multipath effects was developed as a component of the CJ unit.

CJ unit was implemented using USRP and GNU Radio.

Covert Jamming was demonstrated using the proposed testbed

• Malicious users can easily identify the presence of conventional jamming signals and adapt their operations accordingly.

• The goal of this project is to develop Cognitive Jammers (CJ) that overcome the disadvantages of conventional jammers by covertly jamming the malicious users.

• The CJ must also offer least disturbance to friendly users in the frequency band.

The proposed CJ generates a covert jamming signal by taking into consideration the following

•Modulation type used by the malicious users•Type of users operating in the frequency

band•Channel conditions•Energy in the band•Past experience

A three radio cognitive jamming testbed was proposed to test the proposed CJ unit.

An Efficient Jamming System for High Rise BuildingsBei Xie, Majid Manteghi and Tamal Bose

Objective

Impacts, Applications, and OthersHighlights

Ten months’ project

BTS(Femto Cell) BSC

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Multistory Urban Jamming Unit (MUJU)

Fig. 1 Illustration of the new jamming approach

This project investigates a new jamming technique for the GSM system which can reduce the time duration of high-power radiation

in the jamming systemcommunicate with any cellular phone in the

jamming areajam the target cellular phone without being

identified by the user

A SDR (software-defined radio)-based BTS is used• Control the interfaces between MS and BTS

and between BTS and BSC• Control the cellular communications in the

targeted area• Software developing is based on the

OpenBTS and the Asterisk PBX• Off the shelf hardware used as the SDR.

The new jamming concept which can control the cellular communications brings a new level of the jamming techniques The new jamming system can be used for high rise buildings and in many military applicationsThis project is based on the GSM system. Future work includes broadening the new jamming technique to the CDMA system or other systems.

Empower

Objective /Goals

ImpactsHighlights

• Create a tool to simulate large-scale data collection applications deployed to smartphones

• Support high-level metric measurement and monitoring for overall success analysis

• Allows opportunistic or participatory system developers to evaluate the success probability of their developed system in the deployment environment

• The methods of handling smartphone property adaptation can be imported into larger simulation environment for greater awareness and use

• Developed simulation is highly flexible and makes extensive use of the Strategy design pattern

• Simulation environment can flexibly describe a number of environments of interest by loading KML geography files

Hamilton Turner, Jules White

Enhancements to OSSIE Software Defined Radio (SDR) Software and Interface, Carl Dietrich, Stephen H. Edwards, Tamal Bose

Objective /Goals

Impacts Highlights

Period of Performance 2009-2011Sponsor: US ARMY CERDEC

To support ongoing research in OSSIE• The OSSIE project's goals are to enable research and education in SDR and wireless communications. • OSSIE includes:

• an SDR core framework based on the JTRS Software Communications Architecture (SCA)• the Waveform Workshop (tools for rapid development of SDR components and waveforms)• an evolving library of pre-built components and waveform applications.

Improved interface and tools for OSSIE SDR software

A flexible way to demonstrate and use Virginia Tech’s Cognitive Radio Network (CORNET) testbed

Enhanced infrastructure for SDR research and education

To be used in SDR class and research at Virginia Tech and beyond

1 graduate and 3 undergraduate students supported

Explored use of alternative CORBA implementation

Improvements to OSSIE tools

OSSIE/SDR testbed web interface (demo w/CORNET)

Exploring Performance Limits of Multi-hop MIMO Networks via Tractable Models and Optimization

Investigators: Thomas Hou, Scott F. Midkiff

Objective and Approach• Observation: Rapid advances of MIMO

research at the physical layer, but a stagnation of research progress at the network layer

• Our goal: Exploring fundamental understanding of multi-hop MIMO networks

• Approach: Build new tractable and accurate models that are amenable for network level optimization

Impacts• Remove the current barrier facing multi-

hop MIMO network research• Offer new network-level understanding of

MIMO networks• Bridging the gap between wireless

communications research and networking research

• Develop new cross-disciplinary course materials for wireless networking

Highlights

• Develop new tractable and accurate models for MIMO links

• Explore performance limits and optimization for multi-hop MIMO networks

• Design distributed optimization algorithms

Graphic or Photo

Period of Performance: 7/2011 – 6/2014Sponsor: NSF

Flexible Internetwork Stack (FINS) FrameworkA. B. MacKenzie, L. A. DaSilva, and M. S. Thompson (Bucknell U)

ObjectivesDevelopment of an open source reconfigurable protocol stack for experimental research on wireless networks.FINS will provide modules:

To build conventional as well as innovative network stacks using existing or new layers, protocols, and algorithms.To monitor, visualize, and log the behavior of all the stack components.To change the behavior of the networking stack while it is in use by modifying the behavior of individual modules or reconfiguring the stack.To teach networking classes with deeper insight into the network stack.

Why FINS ?

Growing doubt about the fidelity of simulations for the evaluation of network protocols and algorithms.The need to overcome technical and logistical challenges in experimental network research.The lack of well-documented, continuously-supported, and easy-to-use experimental networking tools for research and education. The lack of enabling technologies for the implementation of cyber physical system prototypes.

Use Cases

Prototyping experimental cross-layer solutions.Prototyping delay and disruption-tolerant networking protocols such as bundle and routing protocols. Implementing experiments for reconfigurable cognitive networks as well as cognitive nodes.Implementing wireless ad-hoc network experiments.Prototyping context-aware and localization based solutions.

FINS vs Conventional Stack

Sponsor: National Science Foundation, 9/2009 – 8/2012

Fundamental Limits of Antennas –Quality Factor and Band Performance

Fundamental Limits of Antennas – Quality Factor and Band Performance

Operational and Performance Capabilities - SummaryComplete development of a new limit, correcting fundamental errors of energy velocity in last half-century

Technical Approach:

• Task 1: Complete the development of a new fundamental limit and Add higher-order modes for pattern/gain control• Task 2: Estimate excess stored energy causing interference and added loss• Task 3: Relate band performance to the limit as possible and develop fundamental pole-residue modeling relating the performance and antenna structure in a best estimate sense• Task 4: Construct prototypes to demonstrate beam forming limitations of minimum Q antennas• Task 5: Measure prototype performance in VTAG antenna chamber

Deliverables:• New fundamental limits for multiple spherical modes• Determine the minimum excess stored energy in an antenna system and a potential method for measuring Q• Select prototype antennas and measurements


• Lower bound on antenna Quality factor (Q)• Reduced interference to other systems• Increased efficiency for given size• Maximize bandwidth use• Simpler antenna models for Communication systems• Gain control by mode control

• Reduce inter-ference/Absorbtion

• Improved Efficiency• Simpler Structure• Wideband• Gain

Game Theoretic Models for Cooperation in Wireless Networks

Allen B. MacKenzie

Sponsor: National Science Foundation, 6/2005 –5/2012

The figure shows a network under topology control. Frame (a) shows the network before node j is removed from the network. Frame (b) shows the optimal, network-lifetime-maximizing reconnection of the network. Frame (c) shows a good reconnection solution that relies only on incomplete, local information.

This project is developing a theory of cooperation using game theoretic tools, specifically potential games, to explain how network nodes with disparate and limited information can cooperate to achieve network-wide goals. One application is optimal algorithms for controlling transmission power in a network.A second application is selecting code sequences in a wireless network, so called “interference avoidance.”The project also includes outreach to teach underrepresented middle and high school students about wireless networks.

Objectives

Developed significant new algorithms and proof techniques for interference avoidance in CDMA-like systems.Developed significant new game-theory-inspired algorithms for topology control in wireless networks, which have now been implemented by CERDEC.Currently enhancing these topology control algorithms.Currently working on coalition game-theory based analyses of cooperation in mobile ad hoc networks.Taught hundreds of economically disadvantaged middle school students and high school women about wireless communications through hands on activities.

Highlights Key ReferencesA. B. MacKenzie and L. A. DaSilva, Game Theory for Wireless Engineers. Morgan and Claypool, 2006.R. S. Komali, A. B. MacKenzie, and R. P. Gilles, “Effect of selfish node behavior on efficient topology design,” IEEE Transactions on Mobile Computing, vol. 7, pp. 1057–1070, September 2008.R. Menon, A. B. MacKenzie, J. E. Hicks, R. M. Buehrer, and J. H. Reed, “A game-theoretic framework for interference avoidance,” IEEE Transactions on Communications, vol. 57, pp. 1087–1098, April 2009.R. Menon, R. M. Buehrer, A. B. MacKenzie, and J. H. Reed, “Interference avoidance in networks with distributed receivers,” IEEE Transactions on Communications, vol. 57, pp. 3078–3091, October 2009.R. S. Komali, R. W. Thomas, L. A. DaSilva, and A. B. MacKenzie, “The price of ignorance: Distributed topology control in cognitive networks,”IEEE Transactions on Wireless Communications, vol. 9, no. 4, pp. 1434–1445, 2010.

Geolocating MIMO SignalsDr. R. Michael Buehrer, Jacob Overfield

Objectives

ApplicationsDetails

• Determine how MIMO signals will impact Cross-Ambiguity Function (CAF) • Investigate how Time Difference of Arrival (TDOA) and Frequency Difference of Arrival (FDOA) methods for geolocation are impacted by MIMO signals• Investigate methods for improving geolocation for MIMO signals

• Civilian:• Assisted GPS technologies• Aircraft & Satellite Tracking• Rescue Beacon

• Military:• Locating friends/foes• Tracking

MIMO reduces the max correlation

Intelligence Community Center of Academic Excellence (ICCAE)Reed, Bose, Amanna

Objective /Goals

Impacts Highlights

Period of Performance 2009-2014Sponsor: ODNI

• Develop critical thinking and core competencies in new graduates• Increase awareness of the missions of the IC and National Security• Sponsor study abroad to increase cultural awareness• Develop new curriculum• Host symposiums on IC / National Security Topics• Encourage and assist with internship applications• Sponsor pre-collegiate outreach• Engage with IC for guest speakers and student mentoring

I just wanted to give you a big ‘thank you’ for all that you’ve done with the IC-CAE program. I know that you’ve put a lot of time and effort into helping us out as students and as young professionals. I can’t explain how helpful this program has been and how many doors it truly has opened for me.” – Lucas W

“Again, thank you for all your support and guidance over the pastyear! I feel like IC CAE assisted me so much in my job search process and has been such a fantastic program to be a part of, I've enjoyed every minute. Please let me know if I can assist in any other way or if you have any advice for me as I continue in my career after graduation.” –Kammy M.

21 students sent on study abroad since 2009

104 applications to IC agencies for 2011

Over 100 office hours for 2011

9 IC Guest Speakers for 2011

6 COE to Govt. agencies

4 new courses, 1 certificate, 1 minor, in proposal

STEM outreach to Middle school

Information Theoretic Analysis of MIMO Pilot Nulling Attacks S. Sodagari, C. Clancy

Sponsor: ICTAS

Objective /Goals


Introducing pilot singularity attack for the first timeShowing the effect of jamming MIMO channel sounding

symbols is more destructive than current jamming methods:

e.g. barrage or pilot jamming

Attack attempts to reduce the rank of the channel gain matrix estimate by the receiver

Studying effects on channel bit error rate, capacity, and eigenvalues.Multi-Antenna Pilot Jamming

Attack on MIMO Systems

(a) Mutual Information between MIMO channel matrix and its estimate with no jamming (b) Jammer’s ideal goal in manipulating MIMO CSI at the receiver

Pilots in a 2 × 2 WiMAX OFDM.

Developing constraints associated with jamming MIMO sounding channels

Describing how these attacks specifically impact data symbol estimates for OFDM pilot-based sounding systems

Comparison of perceived MIMO capacity in a 4 × 4 WiMAX vs. SNR with and without differentjamming strategies (20% error in jammer’s CSI estimation)

AUSTIN: An Initiative to Assure Software Radios have Trusted Interactions

Jeff Reed, Tom Hou, Jung-Min Park, Cameron Patterson

Objective /Goals

Impact and ScopeHighlights

• Examine the theoretical underpinnings related to distributed system regulation for software radios

• Develop an architecture that includes trusted components and a security management plane for enhanced regulation

• Research onboard defense mechanisms that involve hardware and software-based security

• Study algorithms that conduct policy regulation, anomaly detection/punishment, and secure accounting of resources

• Holistic approach for regulating software radios• Execution Integrity of Critical Software Modules in CRs

• Using Power Fingerprinting to detect illegal execution• Policy Reasoning Algorithms and Policy Reasoners

• Policy reasoning algorithms and software engines for real-time policy interpretation, process, and enforcement

• Network Resource Optimization for CR Networks• Unifying analytical framework for the multi-dimensional

cross-layer design space of CR for tractability• Configurable Hardware-Assisted Rule Enforcement

Controller for CR reconfigurable platforms• Automatically integrates PHY- and MAC-level policy

enforcement into CR reconfigurable hardware blocks

Period of performance: Sep 2009 – Aug 2011Sponsor: National Science Foundation

• Ensure the trustworthy operation of software radios

• Support the next generation of wireless technology

• Holistic system view

• Deeper understanding of security for highly-programmable wireless devices

• Reduce interference risks and increase trust in CR Technology

• Diverse, multi-disciplinary team

• WINLAB at Rutgers University

• Wireless @ Virginia Tech

• University of Massachusetts

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Inter-dependent Infrastructures: Reliability, Failures and Human-mediated interactions

C. Barrett, .M. Marathe, A. Marathe, A. Vullikanti: VBI, CS, Ag& App. Economics

Objective /Goals

Impacts HighlightsSponsors: NSF, DTRA

Need tools to study interdependencies in the networked infrastructures. End to end simulation system that can not only model and simulate multiple infrastructures but also capture the points of interdependencies among them.

Systematic study of human-initiated disruption, resulting in cascading failures in infrastructures:

Modeling framework to study cascading failures in inter-dependent infrastructures

Activity based framework for modeling traffic congestion, revised cell usage patterns in face of evacuation caused by a chemical plumeTransportation networks, social phone call networks and cellular networksNetwork planning: model effect of changes in call patterns during evacuation and its impact on transportation and spectrum demand

Study how altered human behavior at the time to crisis causes altered activities, travel, route planning and calling behavior. Study the cascading effect of congestion in transportation network on overloading of base stations and altered spectrum demand.

Published in Beckman et al., DySPAN’10, DySPANCRIS’10, CRIS’09

Low-cost Cognitive Radio Technology for Enhanced Communication

and Situational Awareness for Networks of Small UAVsCharles W. Bostian

Objective /Goals

ApplicationsHighlights

This material is based on research sponsored by Air Force Research Laboratory

under Agreement #FA8750-09-2-0128. The views and conclusions contained herein

are those of the authors and should not be interpreted as necessarily representing

the official policies or endorsements, either expressed or implied, of Air Force

Research Laboratory or the U.S. Government.

• Implement CSERE cognitive engine (CE) on

BeagleBoard single board computer

• Provide USAFRL Rome with prototype flight

model CE and cognitive radio CR called UAV

CSERE, suitable for deployment on USAFRL

UAVs

• Cooperate with USAFRL to develop and conduct

live-flight UAV CR experiments for UAV CSERE

• CSERE: CWT’s self-modifiable,

modular cognitive engine

• BeagleBoard: lightweight

compact single board

computer

• Result: flexible multi-band multi-mode adaptive

radio communications for UAV mission success

• Mission resource

conservation: UAVs

share responsibility

for data backhaul

• Link reliability: UAVs with poor link performance

hand off to with better link performance

• Mission Optimization: UAVs optimize link and

position to ensure optimal mission performance

Low Cost Internet Access for Rural IndiaKaran Desai (Adviser: Tim Pratt)

Objective

Highlights

• Create a low-cost alternative to existing satellite based Internet system for villages in India costing users $ 1.00 per month

• Use an aging Ku band communication satellite in inclined geosynchronous orbit to access a village hub station. Link to users with WiFi.

• Determine availability, link budgets, define implementation strategies to make the project economically feasible

• Analyze use of Intelsat 906 in an inclined geosynchronous orbit. Visibility, look angles and availability calculated using simulations and link budget calculations

• It is possible to provide basic Internet access to 96,000 villages on a best effort basis at a cost of $1 per customer per month using one satellite, one central hub and one unmanned earth station per village

Impact• System can help bridge disparity in

Internet penetration in rural India• Design is generic and can be

replicated in any market using different satellites

• Work performed 8/2010 through 4/2011

• Sponsor: Virginia Tech

Machine Learning for LocalizationJavier Schloemann & Dr. R. Michael Buehrer

Objective /Goals

Current Research FocusPotential Applications

Research sponsored through the Bradley Foundation

Trilateration

θ

Triangulation

TDOA Positioning• Improve localization performance

through the use of machine learning techniques

• Utilize intelligent sensor fusion to improve position estimate using all reliable available data

• Fault detection and isolation/exclusion• Dynamic propagation models• Path delay profiling• Integration of multiple localization

techniques• Integration of map knowledge• Localization of sensors in sensor

networks

Localization

Bayesian networks•Exploit conditional independence relationships between random variables to simplify full joint PDFs•Techniques exist which allow for the inferring of unknown data based on the available known data

Mobile Cognitive Radio TestbedPI: Tamal Bose and Jeff Reed

Objectives/Goals

ImpactsHighlights

• Study research issues pertaining to the mobility of nodes •Test developed algorithms, protocols, and applications in a realistic mobile wireless environment • Reconfigurable mobile network• Connect with the network testbed of fixed CR nodes to have larger scale heterogeneous testbed

Example scenarios that can be evaluated with the proposed mobile nodes

Period of performance:May 2010 – December 2011

Sponsor:Army Research Office

• Custom mobile node that includes:• A Small Laptop PC• Pico Expresscard (Virtex-5 FPGA)• Custom RF board (100Mhz to 4GHz)

• Will facilitate the evaluation of scenarios that involve mobile nodes• Will enhance the capabilities of the existing fixed node testbed, CORNET• Can be used both for educational and research purposes

Modeling and analysis of malware in 3G+ networksM. Marathe, A. Vullikanti, VBI and CS, K. Channakesava (Ericsson)

Objective /Goals

Impacts Highlights

Sponsors: NSF, DTRA

Efficient techniques for detection, analysis and control of the spread of malwareNew approaches to capture heterogeneous and mobile networks

Realistic multi-scale models of mobile networks – proximity based (BlueTooth) and InternetScalable tools for simulation and analysis of malware spread on very large networks

Spread of malware in Activity-based networks

Spread of malware in Random mobility models

New ways to control the spread, detect the onset and finding vulnerable devices Mobility matters - Realistic networks are structurally different than simple random networks.Structural differences affect how malware spreads.Underscores the importance of studying human mobility and its impact on wireless networks

EpiCure: HPC-modeling framework that can represent and study malware over urban scale (with millions of nodes), time varying and heterogeneous networks1000 times faster than prior approachesApproach based on epidemics on social contact networks, BlueTooth specific states abstracted out

Approximation error less than 5%

Published in: IPDPS’11, Simutools’09, BioWire’09

Time

Spac

e

Internet worms

Human worms

DaysSeconds

Mobileworms

Threat of malware increasing with smart phones and mobile devicesChallenges: multiple-scales, self forming networks, need to model user behavior

CAREER: Non-Conventional Solutions forEnsuring Security in Cognitive Radio Networks

Objective

Impact and ApplicationsHighlights

PI: Jung-Min “Jerry” Park

• Robust control channel establishment using channel hopping (CH) in Cognitive Radio (CR) networks

• Multiple rendezvous channels per node pair– Robust to link breakage caused by

licensed users or jamming attackers• Bound for time-to-rendezvous (TTR)

– Small channel access delay• No need for global clock synchronization

• A systematic framework of designing CH-based rendezvous protocols using quorum systems (QS)

• Properties of QS properties of CH systems• Optimal CH system designs for rendezvous

– Maximum # of rendezvous channels per pair of CH sequences

– Minimum CH period (Min bound for TTR)– Maintained rendezvous given clock drift

• Jamming-resistant key establishment using frequency hopping

• Fast neighbor discovery and link establishment in multi-channel environments

• Reliable control channel for comm. between heterogeneous wireless devices/networks

TV White Space ~700MHz

Open Source GSM DevelopmentT. Tsou, T. Cooper, S. Carver, C. Clancy, T. Bose

Sponsor: JHU-APL, Army CERDEC

Objective /Goals


Supporting further open-source development of the open-source GSM base station platform, OpenBTS

Has numerous potential applications in federal, commercial, and military scenarios

Project goals:Integrate OpenBTS with OpenBSC to support broader

core network for GSMSupport advanced features, such as Cell BroadcastDevelop a command and control infrastructure for

OpenBTSSupport embedded platforms

Supports R&D into cellular security issues allowing full experimentation with the GSM L1/L2/L3 stack

Educational tool allowing students to develop/deploy cellular infrastructure

Applications in developing and prototyping secure cellular infrastructure by adding advanced features to the cellular network

Interested in expanding work to look at GPRS, UMA, and other cellular technologies

OpenBTS system operating on a

USRP2 software-defined radio

platform

OpenBTS system operating on a

USRP2 software-defined radio

platform

Open Source GSM for White SpacesTamal Bose, Jeffrey H. Reed, T. Charles Clancy

Objective/Goals

Related Software to Be UsedHighlights

Period of Performance: 2010-2011Sponsor: U.S. Army CERDEC

• Develop GSM/DSA single-cell network for white spaces• Test network in GSM-900 (unlicensed ISM-900) band• Study cell loading, call quality, and other metrics

affected by white spaces to assess operation feasibility• Determine feasibility of operating GSM network in white

spaces• Lower costs of GSM network operation

• Cheaper hardware (USRP)• Free open source software• Unlicensed spectrum

Proposed GSM Network in Software:• OpenBTS – BTS with SIP L3 (VoIP via Asterisk) and

Um air interface (via USRP)• Osmocom:

• osmo-bts – BTS with Abis-over-IP and no Um air interface

• OpenBSC – Minimal BSC, MSC, HLR, VLR, EIR, and AUC with Abis-over-IP

Power Fingerprinting Monitor

Pow

er T

race

Software Modules

t

Power Fingerprinting in SDR and CR Integrity AssessmentJeffrey. H Reed and Carlos R. Aguayo Gonzalez

Objective /Goals

Applications and ImpactHighlights

Period of performance: Sep 2009 – Oct 2011Sponsor: National Science Foundation

Match real-time power

traces against trusted

signatures

Malicious intrusions cause deviations from the signatures

• Fine-grained, real-time monitoring of power consumption

• Independent, physically separated sensor

• Embedded or external monitor

• Signatures from trusted implementations or models provide a baseline reference

• Obtained during validation phase in controlled environment

• Feature extraction and anomaly detection

• Compare how closely the observed power consumption matches the signatures

• Demonstrate the feasibility of PFP on commercial platforms

• Identify the best discriminatory features to uniquely identify software execution

• Develop optimal classifiers that include multiple features

• Investigate methodologies to profile software modules and extract reference signatures

• Evaluate the expected performance in terms of detect

• Develop a framework to perform regulatory policy enforcement using power fingerprinting

• Effective mechanism to enforce regulatory policy in SDR and CR

• Detect unauthorized modifications in certified radios

• Intrusion detection and integrity assessment in wireless and embedded systems

• Smart phones industrial control

• Independent of platform, OS, and application

• Effective against zero-day attacks

• Inherent physical protection for the monitor

• Minimal overhead

Predicting Future Locations and Arrival Times of IndividualsIngrid Burbey, PhD

Objective /Goals

ContributionsHighlights

Portions of this research were supported by the U.S. National Science Foundation under Grant DGE-9987586.

1. Predict where someone will be at a future time (e.g. Where will you be at 10:00am?)

2. Predict when someone will be at a future location (e.g. When can I find you in your office?)

3. Do the above with sparse data (non-continuous tracking)

Predicting where someone will be at a future time is straightforward, done with a low-order Markov model.

Predicting when someone will be at a future location can be done using a heuristic model.

• Use of sparse data in location prediction. Existing research assumes continuous location tracking.

• Future location prediction. Current work predicts next location, not future locations.

• Time of arrival prediction.

To support applications which are• contextually-intelligent• proactive instead of reactive• support ubiquitous/pervasive computing

Public Safety Cognitive Radio on a DSP PlatformQinqin Chen, Almohanad Fayez, Alex Young, Nicholas Kaminski, Hedieh Alavi,

Charles Bostian, Michael Hsiao

Objective /Goals

• Recognize all public safety waveforms, 150MHz to 700MHz

• Interoperate with all public safety radios• Provides gateway between incompatible networks• Serves as repeater if desired• Open Source• Modular Architecture• Embedded System

• Low cost• Small size

This chart present work done by Virginia Tech’s Center for Wireless Telecommunications Cognitive Wireless Technologies (CWT) team under National Institute of Justice Award No. 2009-SQ-B9-K011.

• Intelligent and affordable solution to public safety communications interoperability problems• Suitable for manufacture by the LMR industry

During an emergency situation like hurricane Katrina, public safety first responders from different agencies need to communicate effectively with each other, but personnel from different jurisdictions and services frequently use incompatible radios.

Capabilities/Features

Problem

•Improve robustness, reliability, and potential for interoperability of wireless communications for PTC

•Develop a Cognitive Radio (Rail CR) engine and integrate it with a Software Defined Radio (SDR)

•Sense spectrum and performance changes, decide on radio mitigation strategies, implement changes, and learn from past decisions.

•Develop Rail-CR concept of operations, functional requirements, and test case scenarios in simulation and SDR hardware platform

Railway Cognitive Radio to Enhance Safety, Security, and Performance of Positive Train Control (PTC)

Project Objectives

Railroad Impact: Safety & Oversight

Sponsor: Federal Railway Administration Period of Performance: 2009-2011

Enhanced communications with…•Other companies, Base Stations, Signal Switches

Protection against…•Interference (multipath, attenuation)•Intentional jamming

Improved…•Radio link performance, spectrum efficiency

Status

• Rail-CR Concept of Operations 100% complete

• Cognitive Engine 75% complete• Rail-CR simulation 90% complete• SDR test-bed platform 50% complete• Test Plan 10% complete• SDR Integration Manual 10%

complete

PI : Dr. Jeff Reed, Ashwin Amanna

RFID Concepts and Applications-- Currently with Dr. Manteghi --

RFID Concepts and Applications Operational and Performance Capabilities - SummaryAdapt small tag designs to weapon systems and consider design processes without chip to reduce power requirements in the presence of ordance

Technical Approach:

• Task 1: For a given footprint, optimize the design of RFID tags to approach the fundamental limit in bandwidth and gain using appropriate meander techniques• Task 2: Improve the efficiency of small tag structures to improve response to minimal power• Task 3: Develop chipless RFID tags based on pole-residue concepts of antenna structures to minimize power requirements in the system.• Task 4: Design a reader concept to optimize low power operation of a tag in the presence of ordance• Task 5: Build and Measure sample tag structures to demonstrate the performance characteristics

To Be Developed:• Optimized tag antenna design for given footprint limitations• Techniques for improving efficiency• Demonstration of a tagless RFID structure and ID differentiation

Corporate Information:Virginia Tech, Wireless@VT, VA Tech Antenna GroupDr. William A. Davis / Dr. Majid Manteghi302 Whittemore Hall (0111), Blacksburg, VA, 24061Tel: 540-231-6307; Fax: 540-231-3362; E-mail: [email protected]://antenna.ece.vt.edu/

• Maximize bandwidth to the fundamental limits of antennas• Improve efficiency of structure• Minimize power requirements• Evaluate performance in new frequency bands and determine the tradeoffs

• Reduce Size of tag• Maximize Efficiency• Chipless Tags• Minimal Power (in presence of ordance)

SDR Technology DevelopmentJeffrey H. Reed, Carl Dietrich, Peter Athanas

Objective /Goals

Impacts Highlights

Period of Performance 2010-2012Sponsor: US Department of Defense

To investigate and develop SDR related technology

•RF front end and related hardware and APIs

• Requirements and fundamental limitations of wireless communications standards

• Implementations of selected standards

RF front end, related hardware, and APIs will facilitate SDR research

Improved understanding of challenges for SDR implementation of communications standards, perspective for designing new standards

SDR implementations/components for use in research

Several students supported

Hardware and APIs under development

Requirements and limitations investigation and implementations in progress

Secrecy CapacityAnnie Martin, R. Michael Buehrer

Project Goals

Determine the secrecy capacity of MIMO systems.Determine how we achieve this rate, or what rates can we actually achieve.

• If Tx has no channel information• If Tx knows only its intended receiver's channel• If Tx knows only where the wiretapper is• If Tx knows all channel state information

Determine how a transmitter increases this capacity.Determine how a receiver increases this capacity.Determine how wiretapper decreases this capacity.

Highlights

The secrecy capacity is generally the difference between the two channel capacities, which are factors of the channel coefficients, H_r towards the receiver and H_w towards the wiretapper.

MIMO communications are technically using multiple spatial channels, which makes the analysis more complex, as we can choose to use only some of the channels based on our knowledge of the channel statistics.

Why worry about physical layer security?Doesn't need encryption computation:

• Less Hardware• Faster

Additional Layer of SecurityCan hide additional factors of a transmission:

• Presence of signal• Modulation of signal

Disadvantages compared to encryption:Based on stochastic processSignificantly lower data rates

Sponsored by Aerospace Corp.

IntendedDestination

Wiretapper

H_r

H_w

Simulation and Design for Handheld Antennas

Small Handheld System Operational and Performance Capabilities - SummarySimulate candidate antenna and design new antennas for use as UHF embedded antennas on handheld.

Technical Approach:

• Task 1: Evaluate potential antenna solutions for an embedded antenna.

• Task 2: Simulate solutions, possibly with active switching to adaptively tune antenna (Narrowband application over a wide user band)

• Task 3: Evaluate Patterns: Gain and efficiency (Efficiency and Q impact the interaction with the user)

• Task 4: Evaluate Impedance and VSWR

To Be Developed:• Analysis of performance of selected designs• Effect produced by platform• Omni-directional patterns for land-based communications and also arial communications


• Reliability• Performance

• VSWR• Pattern

• Relevant software or hardware specifications

• Low to Mid UHF

• 1Watt

• Efficiency - ?

Simulations for Small Antennas on Combatant Craft

Antenna Simulations for Combatant Craft Operational and Performance Capabilities - SummarySimulate a monopole type structure for use at HF in a small antenna category.

Technical Approach:

• Task 1: Simulation of a loaded monopole structure for mounting on a platform and to be used at HF.

• Task 2: Evaluate Vertical and Azimuthal Patterns

• Task 3: Evaluate Impedance and VSWR

• Task 4: Evaluate different methods of analysis for best numerical simulation performance relative to time and accuracy trade-offs.

To Be Developed:• Analysis of performance of selected design• Effect produced by platform• Elevation pattern needs for vertical radiation

(mechanisms)


• Reliability• Performance

• VSWR• Pattern

• Relevant software or hardware specifications

• Small HFmonopole

• Communications• Low Elevation

• Omni• High Elevation

• Arial

NEXT GENERATION SECURE, SCALABLE COMMUNICATION NETWORK FOR SMART GRID

PI: Jeff Reed, Co-Pis: Mike Buehrer and Haris Volos

Objectives/Goals

ImpactsHighlights

• The core objective is to conduct research, development, and demonstrations leading to next generation secure and scalable communication network for smart grid

Virginia Tech will investigate:• Spreading code and multiple access design for

CDMA mesh networks;• Interference/jamming mitigation techniques;• Multiuser detection techniques; and• Combined communication and position location

using spread spectrum waveforms.

Period of performance:February 2010 – October 2011

Sponsor:Oak Ridge National Laboratory (ORNL)

• A new Smart Grid for the generation, transmission, and distribution of electricity is under development• The Smart Grid is depended on wireless technologies for facilitating its operations• The wireless technologies used must be secure and robust•ORNL has a patented Hybrid Spread Spectrum Direct Sequence and Frequency Hopping waveform• Virginia Tech will assist ORNL with applying their waveform to the needs of the Smart Grid

• Meeting the goals of this project, would provide better support to enhance the cyber-security of communication and control systems specific-to smart grid to efficiently perform the production and distribution of electricity.

A Singularity Expansion Method (SEM) based Space-Time-Frequency (STF) Detection Technique

Late Time: The above time-frequency graph shows how to find the beginning of the late time and time of arrival (time-step 350 for this case).

Increasing Accuracy: The real and imaginary parts of each pole can be fund more accurately in presence of noise

This technique allows us to detect an object using its natural resonances and find its xyz position

MAIN ACHIEVEMENT:• A set of poles (natural

resonances) is added to an object as identification code.

• These poles in addition to the native poles of the structure have been detected from the time

QU

AN

TIT

AT

IVE

IM

PA

CT

EN

D-O

F-P

HA

SE

GO

AL

ST

AT

US

QU

ON

EW

IN

SIG

HT

S

Majid Manteghi, Wireless @ Virginia Tech, [email protected]

Challenges associated with the late-time/early-time issues prevented people to use SEM efficiently and effectively. This work tries to address this issue and integrate it with antenna array to create a space-time-frequency detection technique. One can encode a particular object with a known set of poles to be identified uniquely.

•This work proposes a mathematical technique to use special information in addition to the frequency domain and time domain data to:1. Accurately identify a particular object2.Find its three dimensional position.•The current Singularity Expansion Method (SEM) based detection techniques are not able to distinguish between the early time and the late time response of a particular object from its impulse response. This has been a challenge during last 40 years.

A short-time Matrix-Pencil Method is introduced with a multiple antenna configuration to:

1.Increase the accuracy of the detection method in presence of noise.

2.Separate the early-time and the late-time response from the impulse response of an object.

3.Use the time of arrival of each group of poles at different antenna in a triangulation algorithm to find the position of a particular object

-3 -2.5 -2 -1.5 -1 -0.5 0x 109-15

-10

-5

0

5

10

15

Damping

Freq

, GH

z

domain scattered signal resulting from an impulsive illumination (frequency sweep) using both measurement and simulation data by matrix pencil method.

• The real and imaginary parts of poles have been computed much more accurately using this new technique.

0 1 2 3 4-10

-5

0

5

10

Time (nsec)Scat

tere

d si

gnal

mv/

mHOW IT WORKS: A time window moves from the beginning of the received signal to the end sample by sample. The poles of each time window are computed using MPM. The late-time starts when poles show stable behavior with moving time window.

ASSUMPTIONS AND LIMITATIONS:• The frequency range of the illuminator must

include all the resonant frequencies. Therefore, to detect small objects we need very short pulses.

The starting point

of the late time

0 5 10 15 20 250100200300400500600

Imaginary parts of the poles (GHz)

Tim

e w

indo

w

Throughput Optimization of Cooperative Relaying in Wireless Networks

Investigators: Thomas Hou, Scott F. Midkiff, Hanif D. Sherali

Objectives

• Exploit cooperative communications (CC) in a multi-hop ad hoc network

• Optimize network level throughput via cooperative relaying

• Understand potential and performance limits of cooperative relay networks

Impacts• Advancing a key technology to increase

throughput and reliability of wireless networks

• Offer solutions at the network layer for cooperative relay networks

• Develop new mathematical models and tools

• Develop cross-disciplinary course materials for wireless networking

Highlights

• Optimal use of network coding (NC) in cooperative relay networks

• Relay node selection for throughput maximization

• Explore performance bounds of cooperation in multi-hop relay networks

Graphic or Photo

Period of performance: 7/2011 – 6/2014Sponsor: NSF

Thwarting Software Attacks on Data-intensive Platforms Using Configurable Hardware-assisted Application Rule Enforcement (CHARE)

Mohammed M. Farag, Lee W. Lerner and Cameron D. Patterson

Objective /Goals

Cognitive Radio ApplicationHighlightsSponsor: NSF Period of Performance: 9/1/09 – 8/31/12

Architect a Tailored Trustworthy Space (TTS) on a configurable embedded platform

Want cross-layer enforcement: don’t rely solely on SW integrityMain tool is separation, since sharing is the attacker’s best friendHW oversight of certain SW responsibilitiesSynthesis of rule-enforcing HW controllers on HW/SW

boundariesFormal modeling of controllers enables formal verification of rule

enforcementDesign for performance and design for security are quite

compatible with HW implementation

Construct system partitions and module interfaces from a security perspective

Controllers insulate SW from knowledge of or access to:• Datapath structure, configuration, or parameters• Cryptographic keys• Decrypted HW IP configurations

Application-aware controllers scrutinize SW (even OS) requests and monitor data transfers in real time

• Suits networking, communication, defense, high-reliability, and safety critical applications

Developing tools to automatically embed a subset of application-specific rules into FSM-based HW controllers that are formally modeled, synthesized, and verified

Example of physical layer policies enforced / monitored by an automatically synthesized and formally verified hardware controller (“DREC”) wrapping the baseband datapath:

Tightly Coupled Arrays-- Current PhD Research (USCGA) --

Tightly Coupled ArraysOperational and Performance Capabilities - SummaryApply structure design to a typical Navy scenario and design theelement to optimize bandwidth and gain performance

Technical Approach:

To address the needs of satellite or other directed beam needs with broadband performance

• Task 1: Evaluate the source of surface wave creation and related standing waves within the array• Task 2: Optimize array designs to achieve a 4:1 impedance bandwidth and pattern consistent to equivalent uniform aperture• Task 3: Develop feed networks, including physical supports for phased feeding• Task 4: Employ loading strategies to suppress array guided surface wave• Task 5: Demonstrate wideband performance through simulation


• Reduce array element spacing for wider beam scan• Increase the effective element area over the practical physical

size• Allow for multifunctional array usage by specific element

selection (adaptive array!)• Maximize bandwidth use of planar array (target 4:1)

• Smaller elementspacing

• Larger Effective Areaof element

• Wideband Array• Improved grating lobe

performance

Surface Wave

Resonance

0.9 1.88 3 4 5 6 7 8 9 101

2

3

4

5

6

7

8

9

10

Frequency (GHz)

VSW

R

Dual-band PIFA (simulation)Dual-band PIFA (measurement)Spoon UWB (simulation)Spoon UWB (measurement)

Wideband Antennas

WIdeband Antnneas Operational and Performance Capabilities - SummaryRelate the antenna size to bandwidth, specifically evaluating the related upper and lower frequency limits (Note: typical UWB antenna is a high-pass filter)

Technical Approach:

• Task 1: Based on fundamental limits, develop a characteristic lower bound for frequency, with/without tuning• Task 2: Based on fundamental limits, develop a characteristic upper bound for frequency, with/without tuning• Task 3: Relate pole residue structure of antenna to antenna type: narrowband, UWB, and frequency-independent• Task 4: Relate structural properties that denote narrowband, UWB, and frequency-independent structures• Task 5: Develop and measure prototypes to demonstrate concepts and improved performance

To Be Developed:• New methods for estimating minimum and maximum

frequency limits on antennas• Structural relationship to pole response• Sample antennas and measurements


• Obtain lower frequency bound, with/without tuning• Obtain upper frequency bound, with/without tuning• Pole structure types for frequency description• UWB versus Freq.-indep. Design: performance and pole structure

• Small size limitations• Band Performance

vs size• UWB Concepts• Frequency-Indep.

Concepts• Pole Distribution

Wireless Distributed and Social Computing : Architecture, Protocols & PrimitivesC. Kuhlman, M. Khan, M. Marathe, A. Vullikanti,

Virginia Bio-informatics Institute and Dept. Computer Science

Objective /Goals

Impact Highlights

Sponsors: DTRA, NSF, DARPA

Model driven architectures that scale and exploit context (what, when, where and who)

Bio-inspired paradigms Efficient and robust distributed primitives

Time, message and energy efficientAbility to deal with dynamic networks

HPC-based modeling environments to design and analyze WDC systems

Networks with 100,000 nodes and more

• DASim: An HPC-based modeling environment to study distributed protocols, primitives &contagion in wireless social networks

• Algorithms and Statistical techniques to measure performance of large wireless networks

• CoSMO: Cognitively-inspired architecture for distributed sensing, situation assessment and control

• Efficient distributed algorithms, e.g.Topology controlMinimum spanning tree (MST)Broadcast

Challenges:• Interference• Dynamic topology• Energy is crucial• Time critical • Must be scalable to

large number of nodes

New methods for opportunistic offloading that reduce backbone traffic by 50%Methods for targeting nodes to improve the scope and efficiency information diffusionModels suggest ways to develop wireless architectures that can support energy efficient network primitives

Results published in: IEEE JSAC’09, TPDS’09, INFOCOM’08, WINET’11 MONET.

Future wireless networks cannot be effectively designed, analyzed and controlled in isolation without taking into account the social context

Wireless Distributed Computing (WDC)PI: Jeff Reed

Objectives/Goals

ImpactsHighlights

Develop•Preliminary mathematical models•System level architecture;•Standardized APIs•Algorithms and protocols

Demonstration•Using USRPs (Virginia Tech)•Using WNaN radios (BBN)

Period of performance:August 2010 – August 2011

Sponsor:DARPA

• WDC enables low cost/capability devices to perform demanding tasks to

• Improve computational latency• Improve battery life

• Improves security, a captured device doesn’t have all the data and code• Redundancy, no single point of failure• The wireless channel and battery levels pose a challenge

• Resource management and optimization is required

• Replace expensive nodes with many inexpensive and possibly disposable nodes• Use currently available, but under utilized SDR resources to reduce processing time• New applications can be developed based on the WDC architecture and APIs• The code developed will be available as open source enabling further development of the methods implemented

Wireless Grid Innovation Testbed (WiGiT)Tamal Bose, Xuetao Chen

Objective /Goals

Impacts Highlights

• Develop a wireless grid innovation testbed coordinated by Virginia Tech and Syracuse University with academic, government and corporate partners.• Spur growth of new companies and transformative wireless grid applications.• Facilitate people-to-people, people-to-resources, and people-to-facilities interactions.• Create a Virtual organization by using edgeware and cognitive radio.• Encompass wide-range and geographically dispersed activities and group through VO partnership.

Create four 4 new applications

Emergence notification system

Wireless distributed computing

Distributed Learning

4 Universities joined as VO

2 new graduate courses, 1 in proposal

Several media reports

Wireless Power Via Near Field Magnetic CouplingMajid Manteghi, Devin Williams

Objective/Methodology

Applications

• Achieve strong near field coupling (0dB to -10dB)• Analyze effects of coupler structure on efficiency• Investigate geometric displacement on degradation of coupling strength

-38

-36

-34

-32

-30

-28

-26

-24

-22

-20

dBW/m2

• Difference with prototype due to loss within feeding networks• Research currently investigating high Q replacement networks (coax)• Current prototyping efficiencies: 19-23%

•Single: 22.6%•Array: 20.9%•Strip (pictured): 19.1%

• Electro-mobility Applications

•Biomedical Sensors

•Robotics

•Electric (autonomous) vehicles “charge on the go”

78 79 80 81 82 83 84-50

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0

Frequency (MHz)

S12

(dB

)

SimulationPrototypeSimulation (distributed)

-.35dB

-7.2dB

-4.7dB

200mm

50mm

Analyzing and Improving OFDM for Acoustic Channels

Sponsored by Currently open

Principal Investigator A. A. (Louis) Beex

Researcher/Collaborator Arjun Thottappilly

Project Duration

Ongoing

OFDM (orthogonal frequency division multiplex) communication is useful for the underwater acoustic channel as it can combat the severe multipath that occurs in littoral environments and the Doppler shift that occurs between moving platforms. We completed the DSP implementation of an OFDM communication system using the over-the-air channel. Due to room acoustics, the channel is subject to multipath and – when microphones are moving, with respect to the transmitting speaker – subject to Doppler shift as well. Our efforts are directed towards analyzing the effects of various environmental parameters, as well as towards making improvements in the overall design of the system, such as different approaches to packet and symbol synchronization and to modeling and estimation of the Doppler variations. Experiments show interactions between the presence of Doppler effects and the performance of synchronization algorithms; currently, domains of performance are being established. Ultimately we hope to follow up with measurements and experiments in a large pool and then a lake.

Increasing Utilization of Legacy Channels



Student Researcher

TBD

Project Duration Ongoing

When a particular channel is assigned to a particular user, that channel can – presumably – not be used by someone else. The particular utilization of such a channel can then be quite low, as it remains idle until it is needed. Considering the dearth of bandwidth, or number of channels, it would be good to find a way to use available bandwidth that is not currently in use by the legacy, or primary, user(s). Of course, a secondary user must not interfere with the primary user. Also, the existence of the secondary user should be transparent to the legacy user, i.e. the latter need not be concerned with the existence of the former. It is the secondary user who needs to insure that the channel is only used when it is not in primary use. When the legacy user uses a known modulation format, this creates some a priori information that can be used to facilitate a secondary user. For example, a communications burst often consists of a known synchronization pattern followed by the modulated burst carrying the actual information. The secondary user must sense the synchronization pattern in order to vacate the channel before interfering with the primary user. The detection of the synchronization pattern must therefore be quick. If necessary, the detection process for the start of the primary burst can have a large probability of false alarm to insure that the channel is being vacated in time. Once the channel is being used by the primary user, the sensing task of the secondary user becomes one of detecting when the modulation portion of the CPM burst is over. Generally a different detector is needed to detect the modulation portion of the signal, especially when the signal bandwidth approaches the channel bandwidth. To detect the end of the primary burst, the probability of false alarm (deciding modulation has ended when in fact it has not) must be very low while now the probability of detection need not be very high. We are looking into various modulation detection approaches. Another aspect of this project is to determine to what extent collisions of the legacy and secondary communications bursts impact the performance of the legacy system.

Mitigation of Time-Varying Narrowband Interference and Multipath from CPM



Student Researcher

TBD


Mitigation of time-varying narrowband interference is the first goal of this project. Initial efforts were based on predictive modeling with time-varying coefficients. As CPM signals are finitely correlated, this required decorrelating time-varying prediction. The time-varying prediction system causes signal distortion, expressed in ISI, which can be compensated for because the predictive system parameters are continually estimated and thus “known.” We have shown that this approach can effectively mitigate the interference over some range of ISR (interference-to-signal ratio), to the point where the raw SER (symbol-error-rate) is sufficiently good for a Viterbi decoder to work. Towards extending the usable ISR range, we recently concentrated on a time-varying model for the narrowband interference (i.e. no longer predictive). This approach was indeed successful in expanding the range of performance, even though this came at an increased expense in terms of computational effort. Future efforts are towards jointly modeling the interference and the signal, as well as finding the most practical approaches towards (approximately) solving the resulting optimization problems.

Modeling & Recognition of Transients in Speech



Student Researcher

Areg Baghdasaryan

Project Duration Starting

If we can determine appropriate models for the transients in speech vowels, then the onset of the transient can be detected and the specific vowel identified or recognized. Characterization of the transients in speech is expected to be beneficial for the enhancement of speech coder quality. Another application of the identification task is to be able to associate the particular vowel with the particular person speaking that vowel. This aspect of the project is aimed at speaker identification/verification.

Nonlinear Effects in Adaptive Filtering



Researcher/Collaborator

Takeshi Ikuma (LSU)

Student Researcher TBD

Project Duration

Ongoing

Adaptive algorithms for noise cancellation, prediction, and equalization may exhibit nonlinear effects when operating in environments with strong narrowband interference present. The nonlinear effects are expressed by time-varying or dynamic behavior of the weights of the transversal adaptive filter, even in a wide-sense stationary environment, and performance that exceeds that of the Wiener filter with the corresponding structure. We’ve shown – and analyzed – recently that the mean of the adaptive equalizer filter weights does not correspond to the Wiener weights. The mean-square error of the adaptive equalizer is significantly smaller than that of the fixed Wiener equalizer, and we’ve shown that this performance improvement is borne out in a lower bit-error-rate. An adaptive algorithm for the above environment has been developed for equalization applications and realizes improved performance. We are looking to extend our previous results in terms of applicability to more encompassing environments and to investigate whether – and how – further performance improvements can be achieved.

Robust Automatic Modulation Classification



Student Researcher

Amy Malady


Knowing whether spectrum is being used and to some extent in what fashion – without actually demodulating a received signal – depends on being able to classify what type of modulation is seen, if any. The main approaches are based on time-spectral features and on statistical features. The latter category often exploits any cyclostationarity properties the signal may exhibit. We are looking at the latter approaches and – in particular – towards extending their range of performance, i.e. lowering the SNR required for achieving a certain high probability of correct classification at or below some low level of missed detection. Use of the robust estimator has led to detection, and classification, at lower SNR, for the same or better probability of detection and false alarm as the non-robust approach. The robust approach is also less sensitive to a mismatch between the receiver bandwidth and the signal bandwidth. Importantly, early results indicate that the robust approach achieves the same performance as the non-robust approach using only one tenth the number of observations. CPM signals exhibit cyclo-stationarity of different order, depending on the modulation indices involved. A more practical detector for CPM signals has been designed that is based on second-order cyclo-stationarity only. Next we aim to extend the SNR range of performance for the detection of CPM by making the estimator robust. Further extension will then aim to widen the class of modulations to include CPM.

summary of projects - virginia tech · summary of projects may 2011 ... • runs the cognitive...

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