Cooperative Spectrum Sensing in Cognitive Radio Networks with Weighted Decision Fusion Scheme

Abstract

In cognitive radio networks, both the sensing time and the fusion schemes used for cooperative spectrum sensing affect the detection probabilities of the primary users and the throughput of the secondary users. Therefore, joint optimization of the sensing time and the cooperative fusion scheme has been studied before in terms of sensing-throughput tradeoff design. In this paper, different from the previous studies, we consider the case that each secondary user may have different detection signal- to-noise ratio (SNR), and requires different threshold for energy detection. Weightings are used to weigh the decisions from the secondary users before combining. A new algorithm is proposed to compute the thresholds for the secondary users and the optimal weightings for the decisions are shown. Computer simulations are presented to show the performance of the proposed algorithm.