Spectrum sensing has been identified as the fundamental issue in cognitive radio networks(CRNs). To improve the overall sensing performance, the mechanisms of cooperative spectrum sensing are investigated. Specifically, aiming at the sensing scenario of channel searching, a joint optimized channel-searching scheme is proposed. In this scheme, the base station chooses the optimal searching sequence according to the channels’ static probabilities of being idle, and meanwhile, sets the searching durations of each candidate with different weights. Utilizing this optimal mechanism, the channels with higher idle probabilities can be guaranteed to be searched with higher priorities and longer durations, and thus, the delay due to channel switching and the corresponding QoS loss are minimized. The simulation results show that the average time for finding a new available channel by the proposed searching scheme is always much shorter than that of two existing schemes, and thus, visible performance improvement can be obtained.
