GLRT Based Active Spectrum Sensing for Cognitive Radio Systems

In this paper, we have proposed an active spectrum sensing method which benefits from primary user´s closed loop power control. The idea of active sensing let the cognitive transmitter to use the spectrum by estimating the maximum power of cognitive Radio transmitter that doesn´t lead to harmful interference to primary receiver in the range of primary transmitter. So a cognitive radio can communicate through spatial holes of spectrum. Our work is based on generalized likelihood ratio test (GLRT) model. Using a probabilistic modeling of power profile of primary transmitter and employing energy detection as a channel measurement metric for power statistics, we have developed a GLRT based decision metric for spectrum decision process.