Engineers Develop Wireless Spectrum-Sensing Algorithms

Researchers at Virginia Tech in Blacksburg have developed a set of mathematical rules to help build more reliable and efficient spectrum-sensing techniques needed to meet the expanding demand for wireless technologies. This first phase of a more than two-year study is funded by wireless technology developer InterDigital of King of Prussia, Pennsylvania.

Spectrum-sensing technologies are expected to support high speed internet in rural areas, enable the creation of super Wi-Fi networks, and support the implementation of smart grid technologies, but the task is considered daunting. In a recent report by the Federal Communications Commission on the need to ensure all Americans have access to broadband capability, it was called “the greatest infrastructure challenge of the 21st century.”

Virginia Tech engineering professor Claudio da Silva says a key part of solving this challenge is in the design of wireless systems that more efficiently use the limited radio spectrum resources. “Devices first identify underutilized spectrum with the use of spectrum databases and/or spectrum-sensing,” says da Silva, adding, that following pre-defined rules, they then “dynamically access the ‘best’ frequency bands on an opportunistic and non-interfering basis.

William Headley, one of the Ph.D. students working on this project, describes the first phase of the team’s work. “By exploiting location-dependent signal propagation characteristics,” says Headley, “we have developed efficient sensing algorithms that enable a set of devices to work together to determine spectrum opportunities.”

“The U.S. government has plans to release even more spectrum for unlicensed broadband wireless access,” adds da Silva. “While sensing is not a requirement for television band access, the Federal Communications Commission is encouraging the continued development of spectrum-sensing techniques for potential use in these new bands.”

Photo: Richard Smith/Flickr

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