Events Calendar

Secure Collision-Free Frequency Hopping for STC-OFDM Based Wireless Networks

Speaker: Leonard E. Lightfoot,
Michigan State University,
Department of Electrical & Computer EngineeringAbstract: With the majority of today's transactions and communications relying heavily on wireless networks, the security threats of malicious jamming, detection, and interception are no longer limited to military applications. In fact, security is the key enabler for present and future high speed wireless networks. Patching or add-on security maybe effective in short term, but is far from adequate for addressing the needs on wireless security and can greatly complicate the communication systems. In our research, we focus on the fundamental study of developing a spectrally efficient and inherently secure wireless system by exploiting multiple diversity techniques.We propose an innovative spectrally efficient, jamming-resilient wireless scheme by exploiting the joint space-time and frequency diversity. Existing anti-jamming systems such as frequency hopping (FH) rely heavily on rich time-frequency diversity over large spread spectrums. Mainly limited by multiuser interference, the spectral efficiency of existing jamming resistant systems are very low due to inefficient use of the large bandwidth. While these systems work reasonably well for voice centric communications which only requires relatively narrow bandwidth, their low spectral efficiency can no longer provide sufficient capacity for today's high speed multimedia wireless services. In this research, (i) we develop a collision-free frequency hopping (CFFH) system based on the orthogonal frequency division multiplexing (OFDM) framework and the secure subcarrier assignment algorithm. The proposed subcarrier assignment algorithm is designed to ensure that malicious users cannot predict or repeat the hopping pattern of the authorized users and hence cannot launch follower jamming attacks; (ii) We improve the performance of the CFFH system under random jamming, by enhancing the system diversity through space-time coding, and introduce the space-time coded collision-free frequency hopping (STC-CFFH) system. Our analysis indicates that the proposed scheme is both highly efficient and very robust under various jamming scenarios. The proposed approach breaks new ground in the design and development of secure high speed wireless communication systems. Biography: Dr. Leonard Lightfoot received his B.S degree in Computer Engineering from Xavier University of Louisiana, New Orleans, LA in May 2004. Upon completing his B.S. degree in 2004, he began his graduate studies at Michigan State University, East Lansing, MI, where he received his M.S and Ph.D. degrees in Electrical Engineering in December 2006 and March 2010, respectively. In July 2010, Leonard will join the research team in the Sensors Directorate at the Air Force Research Laboratory located in Dayton, Ohio. Leonard's current research interest includes developing and designing highly efficient and reliable wireless communications, and network security.Host: Michael Neely, neely@usc.edu, EEB 520, 213-740-3505

Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248

Audiences: Everyone Is Invited

Contact: Gerrielyn Ramos