ECE Telecommunications Seminar

"Trellis Processing Algorithms for Sensing-Based Dynamic Spectrum Access in Wireless Networks"

J. Nicholas Laneman
University of Notre Dame

Abstract:
The explosive growth of wireless data services has created pressure for even more effective utilization of the radio spectrum.  Dynamic or opportunistic spectrum access is a recent class of wireless communication and networking approaches that allows secondary users to share spectrum left under-utilized by primary users.  Key system components for efficient dynamic spectrum access are accurate and robust spectrum sensing as well as limited-interference access protocols for secondary users.

In this talk, we motivate Markov models for the access patterns of certain primary users and develop optimal sequence detection algorithms for spectrum sensing of a Markov chain observed in noise.  Our algorithms take full advantage of the process memory and allow trading off missed detections, which lead to interference with the primary user, and false alarms, which lead to reduced throughput for the secondary user.  We point out connections to the well-known Forward-Backward and Viterbi sequence detection algorithms, and illustrate significant performance gains over energy detectors conventionally used for spectrum sensing.  We also develop secondary access algorithms that build upon the sensing algorithms, and finally provide an overview of an experimental demonstration of the techniques. 

Bio:
J. Nicholas Laneman is Founding Director of the Wireless Institute in the College of Engineering, an Associate Professor of Electrical Engineering, and a Fellow of the John J. Reilly Center for Science, Technology, and Values at the University of Notre Dame.  He earned Ph.D. and M.S. degrees in Electrical Engineering from the Massachusetts Institute of Technology, Cambridge, MA, in 2002 and 1997, respectively, and B.S. degrees in Electrical Engineering and in Computer Science from Washington University, St. Louis, MO, in 1995.  Laneman's research interests are in communications architecture---a combination of information theory, signal processing for communications, network protocols, and hardware design---specifically for wireless systems.  He received a PECASE and NSF CAREER Award in 2006, a ORAU Ralph E. Powe Junior Faculty Enhancement Award in 2003, and the MIT EECS Harold L. Hazen Teaching Award in 2001.  He is a member of IEEE, ASEE, and Sigma Xi.

Information:

Cordai Farrar, cordai.farrar@ece.gatech.edu, 404-894-7890 or Matthieu Bloch, matthieu.bloch@ece.gatech.edu