An iterative screening strategy based on detection performance for multi-channel cooperative spectrum sensing

Cooperative spectrum sensing´s false alarm probability and detection probability can be affected seriously when certain SUs with poor detection performance or some malicious SUs exist. To solve this problem, an iterative screening strategy based on detection performance (ISDP) strategy is proposed for multi-channel cooperative spectrum sensing in distributed CR networks. We divide time into fixed-length slots, during each slot, SU first senses channels by energy detection, and then broadcasts its local binary results to others using the common control channel (CCC). Once having received all of the other SU´s binary sensing results, SU immediately executes the SU Adjust strategy to make its own decision on whether to continue sensing in next time slot or not. Finally, a two-slot forgetting function is executed to improve SU´s local detection performance. In this manner, these SUs with poor detection performance can be screened out quickly one by one as time going on. Performance analysis and simulation results demonstrate that under a very easy condition, the ISDP strategy can effectively eliminate these sensing users with poor detection performance, decrease the number of cooperative users, and greatly improve the CR system´s detection performance.