University of Minnesota
University Relations
myU OneStop

Go to unit's home.

Home | Seminars and Symposia | Past seminars/symposia: Monday, November 25, 2002

DTC Seminar Series

Single and Multi-Carrier UWB


Ahmed H. Tewfik
University of Minnesota
Electrical and Computer Engineering

Monday, November 25, 2002
3:00 pm

402 Walter Library

We describe candidate high-bit rate communication systems for short range networking. The highest bit rate system uses a hybrid ultra-wideband orthogonal frequency division-multiplexing scheme. The transmitted signals are sparse pulse trains modulated by a frequency selected from a properly designed set of frequencies. The train itself consists of frequency modulated ultra-wide pulses. The system achieves good detection by integrating several pulses, and high throughput by transmitting frequencies in parallel and using higher order modulation. Unlike traditional orthogonal frequency division-multiplexing systems, a given tone is transmitted only during parts of the transmission interval. We also describe system implementations that rely on properly designed sigma delta modulators to deal with the stringent A/D and D/A requirements of high speed UWB-OFDM. We conclude with an overview of a lower complexity system, lower bit rate system that uses a one carrier UWB scheme to transmit information.


Ahmed H Tewfik (Fellow IEEE) was born in Cairo, Egypt on October 21, 1960. He received his B.Sc. degree from Cairo University, Cairo Egypt, in 1982 and his M.Sc., E.E. and Sc.D. degrees from the Massachusetts Institute of Technology, Cambridge, MA, in 1984, 1985 and 1987, respectively. Dr. Tewfik has worked at Alphatech, Inc., Burlington, MA in 1987. He is the E. F. Johnson professor of Electronic Communications with the department of Electrical Engineering at the University of Minnesota. He served as a consultant to MTS Systems, Inc., Eden Prairie, MN and Rosemount, Inc., Eden Prairie, MN and worked with Texas Instruments and Computing Devices International. From August 1997 to August 2001, he was the President and CEO of Cognicity, Inc., an entertainment marketing software tools publisher that he co-founded, on partial leave of absence from the University of Minnesota. His current research interests are in signal processing for high performance computing I/O, multimedia and short-range high bit rate wireless communications. Prof. Tewfik is a Fellow of the IEEE. He was a Distinguished Lecturer of the IEEE Signal Processing Society in 1997 - 1999. He received the IEEE third Millennium award in 2000. He was invited to be a principal lecturer at the 1995 IEEE EMBS summer school. He was awarded the E. F. Johnson professorship of Electronic Communications in 1993, a Taylor faculty development award from the Taylor foundation in 1992 and an NSF research initiation award in 1990. He delivered plenary lectures at the 1994 IEEE Int. Conf. on Acoust. Speech and Signal Proc. (ICASSP'94), the 1999 IEEE-EURASIP Workshop on Nonlinear Signal and Image Processing, the 1999 IEEE Turkish Signal Processing Conference (SIU'99), the 1st IEEE International Symposium on Signal Processing and Information Theory (2001) and SSGRR2002w International Conference on Advances in Infrastructure for Electronic Business, Science, and Education on the Internet. He gave an invited tutorial on watermarking at the 1998 IEEE International Conference on Image Processing, and another on wavelets at the 1994 IEEE workshop on Time- Frequency and Time-Scale Analysis. He was selected to be the first Editor-in-Chief of the IEEE Signal Processing Letters from 1993 to 1999. He is a past associate editor of the IEEE Trans. on Signal Proc., was a guest editor of two special issue of that journal on wavelets and their applications and is a guest editor of a special issue of the IEEE Trans. on Multimedia on multimedia databases.