In a cognitive radio network, cooperative spectrum sensing is conducted among the secondary users so as to improve the sensing performance. However, it's not necessary to cooperate all users to perform spectrum sensing while achieve a given error bound. In this paper, we investigate the problem of optimal number of secondary users in cooperative spectrum sensing. Moreover, an efficient and robust cooperative spectrum sensing algorithm is presented. A few secondary users are selected to cooperative based on reputation, while guarantee an error bound. Simulation results show the improvement of t...
