Analytical study on the estimation of primary activity distribution based on spectrum sensing

Cognitive Radio (CR) systems utilize spectrum sensing to decide transmission time in an opportunistic manner. Spectrum sensing can also be used not only to determine the instantaneous on/off state of the channel but also to monitor the statistics of primary user to gain information on occupancy pattern. This knowledge can be exploited in many ways to improve CR systems. In this paper, we propose an analytical model to link the sensing period with the observed spectrum occupancy. Moreover, the effect of spectrum sensing periods on the estimated primary activity pattern is analysed. Simulation results show that the proposed model captures with reasonable accuracy the spectrum occupancy observed at the CR.