Spectrum Agile Radio: Detecting Spectrum Opportunities

The opening up of the unlicensed bands for commercial use has been a tremendous success. Wireless communications in computing, mobile, medical and consumer electronics market segments have grown rapidly in the past few years. Due to this success, radio resources in the unlicensed bands are progressively becoming scarce. Recently, the Spectrum Policy Task Force (SPTF) within the FCC has recommended that the FCC regulate spectrum allocation based on market principles. Such regulation implies radio networks wherein radios sense their environment and make opportunistic use of available radio resources while not interfering with the operation of existing licensed networks. In this paper, we focus on a key component of such Spectrum Agile Radio (SARA) systems, namely, the detection of spectrum opportunities. We present results of simulation studies of the use of Hough Transform and autocorrelation function for the detection of spectrum opportunities.