Lei Cao, left. Photo by Kevin Bain/Ole Miss Digital Imaging Services Ramanarayanan Viswanathan, right. Photo by Thomas Graning/Ole Miss Digital Imaging Services
Researcher Lei Cao wins NSF award for work in wireless communications
by Clara Turnage
University of Mississippi engineering professor Lei Cao has been awarded more than $597,000 to improve sensor networks, devices often used by the military to collect and transmit data about their environment.
Cao, a professor of electrical and computer engineering, plans to use his National Science Foundation grant to improve sensor networks by making them more accurate while using less bandwidth and energy. Ramanarayanan Viswanathan, retired professor and former chair of electrical and computer engineering, also contributed to the proposal.
“This new technology proposed for 6G communications is asking, ‘How do we use the available (radio frequency) spectrum most efficiently?'” Cao said. “We know the spectrum is a very precious resource. Companies put in a lot of money to use it to transmit signals.”
Sensor networks can include a broad collection of interconnected devices that pick up and transmit data such as light, vibrations, movement, and temperature to give a broader understanding of the area they observe.
“In the military, it’s used very widely because for a specific area, we can disperse a bunch of sensors and these sensors will be battery-powered and monitor the area if an anomaly happens,” Cao said.
“If, suddenly, there is an object inside this area, the sensors can see that and send that information back.”
Current sensor networks are often battery-powered, use a lot of energy and have trouble transmitting on busy channels, which can pose a security risk in military uses. Cao hopes to use wireless transmission more effectively to make networks more efficient and precise.
“We recently found that if the reporting channel is noisy, it will have errors, and things can be very different,” he said. “What we propose is we try to find the optimal form to transform the sensor information into something else, then transmit the transformed information. This way, we can get the optimal results.”
By transforming the data into a more concise and error-resilient signal, there will be less likelihood of disrupted data or data with errors, he said.
Cao’s work will also involve plans for 6G wireless communications. Sixth-generation mobile networks promise improved data speeds, but the technology is still being developed, he said.
“6G is better than 5G, and 5 is better than 4, but in what?” he said. “In how fast it is and how much data it can transmit. We want to achieve both high power efficiency and high spectral efficiency—to be faster with less use of energy—but there is always a tradeoff between the two.
“The biggest difference between 6G and 5G is in 6G, we’re using a high-frequency spectrum in addition to the spectrum we’re using in 5G, such as the terahertz range—it will be big. But we don’t see any prototypes yet.”
Sensor networks in 6G will provide “near optimal” transmissions, greatly improving the 6G technology by enhancing the shared use of the spectrum among a great number of users, he said.
Outside of military uses, sensor networks can also help researchers monitor the condition of infrastructure and changes to the environment, he said. These civilian applications have not been explored as thoroughly, but could make a big difference in everyday safety, he said.
“Say we want to use multiple sensors to monitor bridge vibrations, then we process this information in a central computing area,” he said. “Then we can see whether the bridge is robust or not.
“You can see, this is related to the environment and the safety of society.”
This material is based on work supported by the National Science Foundation award no. 2408981.
