Using 'smart antennas' for better cellular communication

Researchers with the Canadian Institute for Telecommunications Research (CITR), a federal Network of Centres of Excellence, have come up with a way to increase the quality and capacity of service in cellular communications systems by using 'smart antennas.'

Dr. Steven Blostein, associate professor of electrical and computer engineering at Queen's University, leads the smart antenna project. Several students work under his direction and two are publishing their respective PhD and Master's theses about different aspects of the project.

"If you improve the signals, you can get the same information more reliably, or you can get more information for the same reliability," says Dr. Steven Blostein, of the increase in cellular service quality their work could bring.

As for increasing capacity, smart antenna technology can lead to one of two things: it can either increase the number of users a cellular system can handle, or expand the range of services a cellular system can provide for the same number of users.

Increased quality, more users and/or more services is good news for cellular equipment manufacturers such as Nortel. It could also potentially lower costs to service providers and enable them to have more customers with a wider range of services.

Moreover, a greater range of cellular services means we could see new compact multimedia devices for wireless communication in both voice and data entering the marketplace.

For instance, with a future wireless personal communicator that combined high-quality phone and Internet access, you could sit in the park, surfing the web or faxing a document as you talk to a friend on the phone.

We don't have these innovative tools today because existing cellular systems can't support them. However, as a result of Dr. Blostein's work, manufacturers will know that cellular service providers can accommodate their multimedia equipment and many are wasting no time getting to work on designing such technologies.

"Nortel sees the timely availability of smart antenna technology as providing a competitive advantage for its products in the marketplace," says Mr. Bob Matyas, manager of advanced wireless systems technology for Nortel. "With this technology, everyone can win."

Dr. Blostein was able to increase the quality and capacity of cellular systems by implementing the recent idea of digital beam-forming in an innovative way.

Cellular service is provided by base stations -- central radio towers that receive and transmit cellular signals. By adding an array of antennas with the appropriate spacing to these base stations, and by using sophisticated digital signal processing, Dr. Blostein says it is possible to form beams of energy directed to individual users without knowing where these users are.

"It's sort of like a tracking device . . . a spatial signature," says Dr. Blostein. "It would be like each cell phone having its own wireless wire."

By directing the energy right to and from a user's cell phone (or other future gadget), you would have less ambient noise and less interference from other users and barriers like road underpasses.

"The base station would be able to concentrate on one individual signal instead of listening in all directions," says Dr. Blostein. "And it takes less energy to direct a signal horizontally over 20 degrees than over the full 360 degrees. This energy savings increases a phone's battery life as well."

"If you have twice the coverage, you would logically need half the base stations," adds Dr. Blostein. "This costs less for cellular service providers and it's more aesthetically pleasing."

Technologically, we are just now beginning to produce digital signal processors advanced enough to do the necessary processing -- another reason Dr. Blostein's theory could not be put to use before.

Dr. Blostein's early research results are promising and he is now pursuing patents. He says we could see this smart antenna technology in cellular code division multiple access (CDMA) systems as soon as three to five years down the road. Many of the students who have worked on the project are also finding jobs with such high-tech giants as Nortel, who are keeping a close eye on developments.

"We started the ball rolling with Alexander Graham Bell," says Dr. Nigel Lloyd, of the Natural Sciences and Engineering Research Council, which administers the Networks of Centres of Excellence (NCE). "Today, Canadian researchers are still at the forefront of exciting new tele- phone technology and Canada has become a globally competitive leader in telecommunications."

CITR, which links over 320 of Canada's leading researchers and graduate students in 18 universities with some 15 industrial affiliates, is one of 14 federal NCEs. The $47.4 million-a-year NCE program is jointly funded by Industry Canada, the Natural Sciences and Engineering Research Council, the Social Sciences and Humanities Research Council, and the Medical Research Council.

For more information visit the CITR Web Site.