Thursday, September 17, 1998
4:30 - 5:30 PM
1311 EECS
Abstract -
We look closely at the code design criteria for fading channels
(maximizing effective length and product distance). Based
on these results, trellis coded modulation using asymmetric
PSK signal sets for fading channels are considered.
Simulation results are presented to show that improved
performance may be obtained.
For the AWGN channel when using codes over M-ary signal
constellations the performance depends on the square of
their minimum Euclidean distance. We obtain a lower
achievable asymptotic bound for Euclidean space codes over
uniform signal sets (a signal set in which the distance
profile looking from any signal point is the same). We
obtain bounds for a number of 2, 3 and 4 dimensional signal
sets and compare them based on the bound.
Biosketch -
Education:
1991, B.E. in Electronics and Communication Engg. from
University of Mysore, India.
1993, M.S. in Electrical Engineering from Washington Univ.,
St. Louis, USA.
1998, Ph.D. from Indian Institute of Technology (IIT),
Delhi, India.
Since July 1998 working in IBM, Solutions Research Center,
Delhi, India, as a technical staff member.
Currently visiting IBM, T. J. Watson Research Center in
Yorktown Heights, NY, USA.
Currently working on multimodal speech recognition
problems.