Research On Security Technology In Cognitive Radio Network

Cognitive radio technology solves the problem of shortage of spectrum resources, and improves the utilization of radio frequency spectrum. However, the security problem of cognitive radio network is increasing, which seriously restricts the application and development of cognitive radio technology. The research of security technology in cognitive radio network is of great significance to ensure the security of network, improve the performance of the network, and promote the development of cognitive radio technology.The research work in this paper is as follows:1. studied the cognitive radio network spectrum sensing and security technology. First of all, the spectrum detection of single cognitive user is analyzed, from two aspects of the primary user receiver detection and the primary user transmitter detection, and compares their advantages and disadvantages. Then analyzed the multi cognitive user cooperation detection and data fusion criterion. Finally, summarized the existing defense technology, including the primary user location detection, channel feature detection, fingerprint detection and so on.2. Basing on the advanced encryption standard to defend the primary user emulation attack. Firstly, the impact of PUE attacks on the legitimate users and network performance is studied, and then the AES encryption and encryption processes are studied to explain the high security of AES encryption. At last, the AES encryption technology is applied to defend the PUE attack. The method can detect the attacker by the cross correlation of the signals, the simulation results show that this strategy can reduce the probability of false detection, effectively defend PUE attacks.3. Basing on the wireless channel characteristics to defend the PUE attack. Firstly, the propagation characteristics of the wireless channel are studied, and the Doppler expansion and delay propagation of the small scale fading are analyzed, and the commonly used statistical models are summarized. This strategy is based on the characteristics that impulse response is approximate invariant in the channel coherence time. The channel is different between attacker and legitimate users, and the impulse response also has a big difference. Then the least square channel estimation and the least mean square error channel estimation are studied and the advantages and disadvantages of the two are compared. At last, the method of PUE attack detection by channel impulse response is studied, which using channel estimation algorithm to extract impulse response and determine the user's identity. Simulation results show that this method can effectively identify the attacker, achieve the purpose of defending PUE attacks.