A Scheme Against The Malicious Primary User Emulation Attack In The Cognitive Radio Networks

Cognitive radio technology enhance the utilization rate of spectrum resources.That can alleviate the problem of spectrum resource constraints. It requires the secondary users not interfere with the primary users and dynamic opportunistic access authorization spectrum spectrum holes, in order to make full use of the scarce spectrum resource. At the same time,it has introduced some security problems. The primary user emulation attack(Primary User Emulation, PUE) is a great potential security threats in the cognitive radio network, it can lead to severe Do S(Denial of Service) problem. The PUE attack problem in cognitive radio networks has already been research. But most of the research of PUEA are based on position information and distance breakdown model. The research on conventional model under the PUE attack is also defective. We mainly to research the conventional model under the PUE attack and defense strategies in cognitive radio networks.Firstly,We analyze several technology against PUE attack. The energy detection method as a non coherent detection method is a simple, widely used. The most important is the energy detection algorithm is optimal algorithm when the signal is unknown. According to the improved energy algorithm,we found that the improved energy detection is not only suitable for very low signal-to-noise ratio situations.By the simulation,we found the improved energy detection algorithm is also suitable for the high SNR.Secondly, in the traditional model we analyze the impact of malicious primary user emulation on the system.The PUE attack will make a system existence "detection performance bound" in the cognitive system and makes the system detection performance deterioration and interference to primary users. In this paper, the improved optimal weighting scheme is proposed based on the improved energy detection algorithm and the soft fusion strategy. The simulation results show that: the scheme proposed in this paper can reduce the impact of malicious primary user emulation attack on the the system effectively.