Adaptive operation scheme for quiet period in IEEE 802.22 system

In IEEE 802.22 system, the quiet period for spectrum sensing consists of a series of consecutive energy detections followed by feature detection. In this paper, an adaptive operation scheme for quiet period in the IEEE 802.22 system is proposed and its performance is investigated, where the length of sensing interval is adaptively varied depending on the number of alarms by the energy detection. The effect of intra-frame cycle length is also investigated. Numerical results show that the proposed scheme may improve the channel utilization of cognitive radio system by 5% to 20%.