Evaluation of energy detection for spectrum sensing based on the dynamic selection of detection-threshold

Cognitive radios (CRs) have been proposed as a possible solution to improve spectrum utilization by enabling opportunistic spectrum sharing. The main requirement for allowing CRs to use licensed spectrum on a secondary basis is not causing interference to primary users. Spectrum sensing allows cognitive users to autonomously identify unused portions of the radio spectrum, and thus avoid interference to primary users. In this work, energy detection technique is considered for spectrum sensing, and the performance evaluation of an energy detector is presented. The process of threshold selection for energy detection is addressed by the Constant False Alarm Rate (CFAR) method and selection is carried out considering present conditions of noise levels. Our results show that if we dynamically adjust detection-threshold based to the noise level present during detection process, the detection probability will be higher than the one obtained when a fixed threshold value is considered.