ABSTRACT
Cognitive radio technology is proposed to solve the problem of low utilization rate of spectrum. With the rapid development of cognitive radio technology, security threat appears. The primary user emulation attack is a common attack in the security threat [1]. It is divided into selfish and malicious attacks. The selfish attack is actualized by a pair of users, who communicate by sending out a signal similar to the primary user’s signal in this band. The malicious attack is caused by the attacker who sends out signal continuously to prevent other users’ access. One of the important issues in Cognitive Radio Network is to distinguish between the primary user signal and the attacker signal. Yunfei-Chen proposed the improved energy detector [2][3]. It can improve the performance of the detection, compared with the traditional energy detector. The cooperative spectrum sensing sends the sensory information to the fusion center [4] [5] to determine the presence of primary user through a fusion criterion. Hard fusion and soft fusion are the main methods to fuse the sensory information. The soft fusion is better than the hard fusion in fusion effect. The soft fusion is used in the scheme. Due to the impact of MPUEA, the detection performance of system declines sharply. It cannot be improved by increasing the transmission power of PU. The optimal weighing coefficients are obtained by maximizing the probability of detection and minimizing influence of MPUEA on the system.
