Coding: from Information Theory to Hardware

SPEAKER: Dr. Oliver Collins, University of Notre DameABSTRACT: This talk presents new results in both the outer (channel coding) and inner (transmitter hardware) layers of communication systems. The first part of the talk introduces the concept of coding for variable channel coherence. The need for this type of coding arises naturally in the multi-user broadcast channel since the more mobile a terminal, the harder it is for it to maintain coherence. The talk shows that non-coherent users can be accommodated without loss to the overall capacity, as long as there are not too many of them. This argument leads naturally to an efficient (capacity lossless) method of using codes designed for memoryless channels on channels with memory and to new ways of calculating the capacity of fading channels.The second part of the talk explains how a low rate purely digital code labeling a trellis can be used to perform modulation as well as coding. This new approach allows for a completely digital transmitter. There are no analog up-conversion stages required at the transmitter; the binary stream coming out of the modulator is simply filtered and directly radiated. The talk concludes with experimental results, i.e., real RF measurements for GMSK and BPSK and a demonstration of a working prototype.Bio: Oliver M. Collins (Fellow 2002) was born in Washington, DC. He received the B.S. degree in Engineering and Applied Science in 1986, and the M.S. and Ph.D. degrees in Electrical Engineering in 1987 and 1989, all from the California Institute of Technology in Pasadena, CA.From 1989 to 1995 he was an Assistant Professor and later an Associate Professor in the Department of Electrical and Computer Engineering at the Johns Hopkins University in Baltimore, MD. In September 1995 he accepted appointment as Associate professor in the Department of Electrical Engineering of the University of Notre Dame, Notre Dame, IN. He was promoted to full professor in 2001 and teaches courses in Communications, Information Theory, Coding, and Complexity Theory. He received the 1994 Thompson prize paper award from the IEEE, the 1994 Marconi Young Scientist Award from the Marconi Foundation, and the 1998 Judith Resnik Award from the IEEE.Host: Dr. P. Vijay Kumar, vijayk@usc.edu

Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248

Audiences: Everyone Is Invited

Contact: Mayumi Thrasher