Wednesday, April 19, 2000 B102 Wells Hall:

• 4:00 pm     Robert Calderbank
                   "Orthogonal Designs and Space-time Codes for Wireless Communication"
• Abstract: Matrices of indeterminates with orthogonal columns appear in the mathematics literature as Orthogonal Designs. The existence of orthogonal designs is a subject that occupied Radon and Hurwitz in the 1920s. This talk describes how these designs are used to construct Space-Time Codes that dramatically improve the throughput and reliability of wireless systems employing multiple antennas at the base station and at the mobile. A Space-Time Code derived from a particular 2X2 Orthogonal Design is incorporated in the wideband CDMA standard that will support 3rd generation wireless services in the 2001-2003 timeframe. There may be as many as 1B mobile phones using this arcane mathematical structure.

For additional information:

Department of Mathematics
Michigan State University
East Lansing, MI 48824-1027
(517)355-9680
ginther@math.msu.edu
http://www.math.msu.edu/Lecture_Series