Anti-Eavesdrop In Cognitive Radio Networks Base On Beamforming And Incentive Mechanism

Wireless spectrum, as a kind of non-renewable resources for human has an irreplaceable role in the development of information technology. But with the development of information technology over the years, the demand for spectrum resource of many new industries and business explosive development, the shortage of spectrum greatly inhibits the development of these new industries. The emergence of cognitive radio technology, offers a new way to solve this contradiction, it uses dynamic spectrum allocation strategy, greatly improving the efficiency of spectrum utilization, easing the shortage of spectrum resources.Because of the reality that the tense and distribution imbalance of spectrum the research of cognitive network has very realistic significance, but at the same time, the cognitive radio technology not only brings new security threats but also more likely to suffer from the traditional network security threats, such as the characteristics of CR amplifies the eavesdropping and jamming of malicious nodes in traditional network. Usually the solution of the communication security stays above the network layer and uses the encryption technology, but it this way, there still has possibility of threats in communication.In this paper we study the eavesdropping of cognitive radio network, and put forward the physical security scheme based on cognitive user collaboration, the primary user’s security capacity has been improved through the secondary users collaboration beamforming, in return, the PU will assign a certain period of time slot to the SU so this system allows the SU to completely use the primary user’s channel to improved it’s channel capacity. To the aspects of resource allocation in combination with system information parameters we study the boundary conditions which affect user collaboration, and so that the necessary constraints of choose for relay has been provided. On the other hand, in the course of the relays’collaboration beamforming we study the security based on with zero space constraints capacity criterion, for the error evaluation of expect eavesdropping channel, we put forward a distributed virtual zero space widened algorithm, improved the system robustness under the condition of the imperfect channel estimation.