Posted Sep. 20/04

By Peter Severinson

Whenever a cell phone connects two people, or one computer links to another through the Internet, information is always lost.

Saied Hemati (right), Ph.D. student in Systems and Computer Engineering, with Professor Amir Banihashemi

Compensating for the loss is a major challenge in the development of communication systems. Saied Hemati, a Ph.D. student in Carleton’s School of Systems and Computer Engineering, however, is working on a way to do it faster and for less money.

A common way of solving the problem is to add redundancy to the information being sent. “[It’s like] trying to spell a strange name over the telephone,” Hemati explains. “You say, for instance, ‘C like Circle’.”

This gives the receiver the directions it needs to understand a message even though some of it is missing. In the case of electronics, this is done through coding. The receiver first has to decode the message before it can be understood, which can require a lot of computation.

The standard method for decoding is with digital circuits, where a group of transistors deal with a series of ones and zeros.

Instead, Hemati is designing an analogue circuit that allows each transistor to issue a range of values instead of just one at a time. It means reducing the number of transistors required to communicate a message, making the process more efficient.

“By moving toward analogue, it’s much smaller...it’s less expensive and it consumes less power,” says Hemati.