Gradient-Based Threshold Adaptation for Energy Detector in Cognitive Radio Systems

Cognitive Radio (CR) systems have been proposed to enable flexible use of the frequency spectrum in future generations of wireless networks. These are expected to detect spectrum bands that are not actively used by licensed (primary) users and provide unlicensed (secondary) users access to these bands. In this context it is important for the CR systems to promptly react to changes in the operating environment and to adapt to the changing patterns of spectrum use. This motivates the work presented in this paper, which studies adaptation of the detection threshold for energy-based spectrum sensing in dynamic scenarios under constraints imposed on the probabilities of missed detection and false alarm.