Clear paths for information

It's a familiar experience to cell-phone users: Suddenly, in the midst of a call, the voice of the person on the other end starts to fade in and out or, even worse, disappears altogether.

But, now, a College of Engineering researcher is working on a way to eliminate this problem.

"My work focuses on communications, signal processing and bioinformatics," says Javier Garcia-Frias, assistant professor in the Department of Electrical and Computer Engineering. "The common link of all my research is the development of methods and tools for more efficient processing of information."

Garcia-Frias emphasizes the difference between data and information. In wireless communications such as cell phones, the received data has to be processed so that the correct information is obtained. The same is true in bioinformatics, which is the study of the inherent structure of biological information and biological systems.

The human body, for example, houses a wealth of systematic biological data, but it has to be decoded for researchers to extract the information of interest--for instance, how various genes interact and are expressed.

"In both cases, we're trying to extract information from systems in which 'noise' is obscuring the message," Garcia-Frias says.

In the communications field, he explains, the approach to reducing or eliminating that noise is to add redundancy to the system, allowing recovery of data without errors. Digital systems, such as digital televisions, phones and computers, all transmit information through a binary system of zeros and ones.

"A very simple and un-efficient method to achieve protection against the noise is to repeat digits," Garcia-Frias says. "Instead of a single zero, for example, we can put in 10 zeros, so that if some are lost, the message is still transmitted accurately."

Designing and applying error-correcting codes is not as simple as it sounds, he notes. Garcia-Frias began working with these codes when he went to the University of California at Los Angeles as a doctoral student in the mid-1990s. His interest in the field had been sparked when he worked at the research labs of the telephone company in his native Spain after earning
a master's degree at the Polytechnical University
in Madrid.

"The codes that had been developed at that point, in 1993, performed well and were working close to their theoretical limits," he says. "But, they were designed for simple channels, while wireless channels are not at all simple. They're characterized by bursts of errors." His contribution has been to modify the codes so that they work on more realistic channels, such as those encountered in wireless phones and computers, ultimately preventing lost connections and enabling clearer communication.

Garcia-Frias says his work is quite basic, involving modeling and computation, but its potential applications are wide-ranging. In a related project, he is working to exploit the correlations among sensors in a network to reduce the power requirement needed to transmit data from the network. Currently, the information from the various sensors is treated as independent, even though it actually all has a common focus. Identifying and capitalizing on the correlations is, however, an extremely complex problem, Garcia-Frias says.

In addition to his appointment in the Department of Electrical and Computer Engineering, Garcia-Frias is affiliated with the Delaware Biotechnology Institute, where he is collaborating with researchers from UD and other institutions, including Thomas Jefferson University Medical School in Philadelphia. Just as the data transmitted across a telephone line is intended to send a message to the receiver, the genes in the body follow a pathway of information expression.

"When we extract information from the genome," Garcia-Frias says, "we can use it to make predictions about a person's predisposition toward disease. That same information can also be the basis for the design of new medicines and drug delivery systems."

Since joining the UD faculty in 1999, Garcia-Frias has been awarded two prestigious grants for young faculty from the National Science Foundation--the Faculty Early Career Development, or CAREER, Award and the Presidential Early Career Award for Scientists and Engineers. These and other grants are supporting his research program, providing funding for six graduate students.

Garcia-Frias is no stranger to awards. In 1993, he was selected by the Spanish government as one of the top three electrical engineering graduates in the country.

Today, Garcia-Frias stands to play an important role in how information is processed in the 21st century, by pathways as basic as those in the human body and as high-tech as those in the latest wireless devices.

--Diane Kukich, AS '73, '84M