[1] Missouri Univ Sci & Technol, Elect & Comp Engn Dept, Rolla, MO 65409 USA
[2] US Air Force, Res Lab, Informat Directorate, Rome, NY 13441 USA
[3] Univ Notre Dame, Dept Comp Sci & Engn, Notre Dame, IN 46556 USA
[4] Univ Notre Dame, Dept Elect Engn, Notre Dame, IN 46556 USA