Improvement of Detection Performance Using Cooperative Diversity in Multiple-User Cognitive Radio Networks

Cognitive radio has been proposed recently as the means to improve spectrum utilization, where the cognitive users (also referred to as secondary users) are permitted to share spectrum resource with the primary user. In this paper, we investigate the spectrum sensing by using cooperative diversity in multiple-user cognitive radio networks. A novel cooperative spectrum sensing scheme based on the best relay selection is proposed to improve the detection performance. We develop the closed-form expressions of detection probability for traditional non-cooperative scheme and the proposed cooperative scheme over Rayleigh fading channels. Numerical results show that our scheme outperforms the traditional non-cooperative scheme in terms of detection probability. Furthermore, the improvement of detection performance increases with the growth of the number of potential users in cognitive radio networks.