_*Notice and Invitation*_ Oral Defense of Doctoral Dissertation The Volgenau School of Engineering, George Mason University *Hossein Roufarshbaf* Bachelor of Science, Isfahan University of Technology, 1999 Master of Science, Amirkabir University of Technology, 2002 *A Tree Search Approach to Detection and Estimation with Application to**Communications and Tracking* Wednesday, July 20, 2011, 1:00pm-3:00pm Nguyen Engineering Bldg., Room 3507 All are invited to attend. _*Committee*_ Jill K. Nelson, Chair Andre Manitius Kuo Chu Chang Gerald Cook _*Abstract*_ A novel approach to detection and estimation problems using tree search techniques is presented. The problem is framed as a generalized sequential detection problem in which every possible sequence of system states is mapped to a path through the search tree. The stack algorithm and the M-algorithm that are originally used in decoding of the convolutional codes are implemented to reduce the computational complexity of the tree search technique. The proposed tree search technique can be viewed as approximating the full Bayesian inference approach by computing the posterior distribution only in regions in which it has significant mass. Unlike approaches that build on Kalman filtering techniques, the proposed stack-based tracker suffers no performance loss in the presence of nonlinear and/or non- Gaussian system state space model. The proposed algorithm is successfully applied to blind channel equalization, modulation classification and target trackingproblems. A copy of this doctoral dissertation is on reserve at the Johnson Center Library.