2010 REU


Richard Adjogah - University of Maryland, Baltimore

MayPat Beaufait - University of Michigan, Ann Arbor

Stephanie Bruzek - Virginia Tech

Duyun Chen - University of Pennsylvania

Tyshawn Colter - St. Augustine College

Matthew Gallant - Virginia Tech

Fitwi Hailegiorgis - Virginia Techv

Ludwig Lopez Cortes - University of Puerto Rico, Mayaguez

John Newman - Virginia Tech

Takuya Otani - Cooper Union

Natali Pujois - University of Puerto Rico, Mayaguez

John Roper - Virginia TEch

Luis Santiago Roman - Univeristy of Puerto Rico, Mayaguez

Nilda Trujilo - University of Puerto Rico

Garreti Vanhoy - University of Arizona



2010 Group PhotoThe Research Experiences for Undergraduates (REU) program supports active research participation by undergraduate students in any of the areas of research funded by the National Science Foundation. Our REU site is focused on cognitive communications. This is the second year of a three year program. This year we are hosting 15 students, 5 of which are Virginia Tech undergraduates, and the rest are from across the United States and Puerto Rico. Three of the REU students are supported by a gift from Northrop Grumman given to the ECE Department. Each student is assigned a mentor who will supervise their research. Dr. Tamal Bose is the Principal Investigator on the project and Dr. Tonya Smith-Jackson is the Co-Principal Investigator. Other mentors are Dr. Carl Dietrich, Dr. Kay Thamvichai, and Dr. Tim Newman.

The students are assigned to teams. After discussions with the faculty, each student team will select an innovative problem-focused project, conduct a literature search and trade analysis, read assigned research papers, and write a detailed prospectus for their proposed research project. Each student team will work directly with the faculty members who are supervising his/her project to code the research questions and hypotheses to test in simulation and/or experimental platforms and to demonstrate the workability of the specific ideas. After the research project is complete, they will present their results in a conference setting. Various social activities are arranged so REU participants and faculty members can establish camaraderie. So far, the students have met students from other REU programs at Virginia Tech at a pizza party. The students and mentors also went on a hike to the Cascades recreation area, where we could highlight the region’s natural beauty.

The REU participants are expected to contribute and advance their chosen research with the help of their relevant teams of faculty mentors and to gain appreciation for and an interest in graduate school and a future research career. The final results from the summer research activities will be a project in cognitive communications and a research paper, to be submitted as part of a larger work to a research journal or conference for publication.



Student Papers, 2010

Digital Modes for Ionospheric Radio Network ( Paper – Presentation)

Ludwig López, Inter American University of Puerto Rico – Bayamón Campus

Abstract—This paper presents a recommendation of a modern digital mode to transmit textual information over the HF band. This mode will be used in an interstation communication system for a network of geophysical measurement stations in the Antarctic. An HF channel simulator was used to develop effective comparative tests for all selected digital modes. The results from the channel simulator helped in choosing the correct digital mode according to the most reliable text transmission.

Development of a detection strategy of ionosphere irregularities using GPS measurements ( Paper – Presentation)

Luis J. Santiago-Román, Inter American University of Puerto Rico-Bayamón Campus

Abstract— In this paper we present a strategy for the detection of ionospheric scintillations based on Global Positioning System (GPS) signal measurements. Many parameters derivable from GPS signal can be considered for the detection of scintillation. ,, decorrelation time and complex power spectral density are some of them. In this paper, we propose an algorithm based on and computation. The algorithm requires a set of threshold values for Threshold values were determine by testing the proposed algorithm on simulated and real data set of threshold values.

Dynamic Spectrum Access: A Radio Security Perspective (Paper)

Stephanie M. Bruzek, John M. Newman, and Fitwi Hailegiorgis

Abstract—Dynamic Spectrum Access (DSA) is a newtechnology that is swiftly becoming the solution to the depletionof available spectrum. With programs such as the DARPA XGworking to study and develop this technology, it has grownincreasingly in the past several years and has been making itsway into the U.S. Department of Defense’s equipment. ThoughDSA technology was developed to solve this problem of spectrumusage, it has also created another: equipment security.In this paper we provide a security analysis on the DSA 2100radio, a radio developed by Shared Spectrum Company underthe DARPA XG program. Our analysis demonstrates thesecurity vulnerabilities that exist within DSA technology andidentifies several unique attacks that are easily reproducible by amalicious user. We also identify several mitigation techniquesthat could be used to prevent these attacks.

Spectrum Sensing Techniques Based on Primary Transmitter Detection (Paper – Presentation)

Natali Pujols and Nilda Trujillo Wireless@VT, Virginia Polytechnic Institute and State University {natali.pujols, nilda.trujillo}@upr.edu

Abstract— Frequency bands are a scarce resource at the moment. Efficient use of them could lead to better spectrum sharing between primary and secondary users, in particular cognitive radios. To achieve this, spectrum sensing techniques are implemented. Four of these techniques, Energy Detection, Matched Filter Detection, Covariance Based Filter Detection, and Cyclostationary Based Detection, are evaluated in this paper for different modulations schemes.

A novel approach in modulation classification using higher-order statistics and the discrete wavelet transform (Paper – Presentation)

Takuya Otani, Matthew Gallant, and Tyshawn Colter

Abstract— A modulation classification method based on a combination of higher-order statistics and the discrete wavelet transform is proposed. Conventionally, the discrete wavelet transform is used to identify the modulation scheme (i.e. PSK, QAM, FSK) of an unknown signal, but is not used to determine the modulation order. Higher-order statistics are used to determine both the modulation scheme and modulation order. In the proposed classifier, higher-order statistics and the discrete wavelet transform are used in conjunction to create a hierarchical method in which the discrete wavelet transform is used to classify the modulation scheme, and then a combination of discrete wavelet transform and higher-order statistics are used t determine the modulation order. This method successfully works in low SNR conditions to find both the modulation scheme as well as the modulation order of an unknown signal.

Using Case Based Reasoning in a Cognitive Engine (Paper– Presentation)

Richard Adjogah, John Roper, NSF REU: Cognitive Radio

Abstract—A cognitive radio is made up of many parts, but the most complicated is the cognitive engine that coordinates everything else. The engine has to be able to monitor its own performance and yield an optimized output to the transmitter based on inputs from the environment. This paper documents an approach to using jCOLIBRI as a case based reasoning system for use in a cognitive radio engine. It was tested using simulated data packets sent in an OSSIE waveform.

OSSIE/GNU Radio Generic Component (Paper – Presentation)

, Garrett Vanhoy, and MaryPat Beaufait Advisor: Dr. Carl Dietrich

Abstract—A Generic Component (GC) was created to combine OSSIE and GNU Radio (GR), two widely used development suites for Software-Defined Radio. The GC is an OSSIE component which can encapsulate one or more GR blocks and provide the necessary data conversions to interface OSSIE I/O with the GR blocks. The GC was designed to change the encapsulated GR blocks and the GR block properties in near real-time. Preliminary tests were performed on the GC to evaluate the time it takes to reconfigure. The tests demonstrated that the GC can be reconfigured in near real-time without adding significant processing overhead. Possible applications for the GC are discussed.

Presentations, 2010

The work culminated in a symposium and presentation of certificates of completion. The conference gave the students experience that they can use during the rest of their undergraduate studies and beyond. The final presentations included:

“Interstation Communication Method Based on Dynamic Data Collection”

•Group Members: Ludwig Lopez Cortes and Luis Santiago Roman

“A Reconfigurable OSSIE/GNU Radio Component and WBAN Applications”

•Group Members: Duyun Chen, MaryPat Beaufait, and Garrett Vanhoy

“Automatic Modulation Classifier”

•Group Members: Takuya Otani, Tyshawn Colter, and Matthew Gallant

“Using Case Based Reasoning in a Cognitive Radio Engine”

•Group Members: John Roper and Richard Adjogah

“Spectrum Sensing Techniques”

•Group Members: Natali Pujols and Nilda Trujillo Reyes

“Dynamic Spectrum Access: A Radio Security Perspective”

•Group Members: John Newman, Stephanie Bruzek, and Fitwi Hailegiorgis Roper and Adjogah Beaufait, Vanhoy, and Chen Dietrich and Smith-Jackson (mentors) Nealy and Santiago Roman (mentor)

2010 REU Symposium Photos: