Detection Performance Analysis for the Multiple-User Cooperative Spectrum Sensing Scheme with the Best Relay over Nakagami Fading Channel

In order to improve the detection performance of cognitive radio networks, the system model is improved based on a multiple-user cooperative spectrum sensing scheme with the best relay in this paper. A cooperative detection border is proposed that whether relay users are needed for cognitive user. Therefore, selecting the best relay is operated according to the quality of channel, and a theoretical analysis is introduced for detection performance of the scheme over Nakagami fading channel, then theoretical expressions of detection time and agility gain for non-cooperative scheme and the proposed scheme are derived. In addition, numerical results are proceeded in according to those theoretical expressions in order to verify the superiority of the proposed scheme. The results show that detection time is reduced substantially and agility gain is also increased greatly by the multiple-user cooperative spectrum sensing scheme over Nakagami fading channel.