Study On Weight-based Spectrum Sensing And Allocation Scheme In Cognitive Radio Networks

With the development of wireless communications technology, there has been an increasing number of requirements to spectrum resources. But the mechanism of wireless spectrum distribution available doesn't satisfy the increasing requirements of more and more users', and the problem in scarcity of spectrum resources occurs. The significant reason to this problem is the static principle of spectrum distribution. Cognitive Radio technology creates a new way to resolve the problem caused by increasingly rising radio communication services and limited spectrum resources ultimately.Because basic idea of CR is to make wireless terminals have the ability to detect vacant spectrum and make full use of them, the realization of cognitive radio system depends on the implementation of spectrum sensing technology. With dynamic spectrum access technology, CR system meets with the new security problems, such as primary user emulation (PUE) attacks and spectrum sensing data falsify (SSDF) attacks.In this paper we propose a weighted-based cooperative spectrum sensing scheme in the stage of spectrum sensing after in-depth research on spectrum sensing technology of Cognitive Radio. The scheme can make users with weight have different influence to integrated decision of fusion center, and give all sensing users different weight value. Statistics results indicate that this scheme has a higher efficiency than the traditional cooperative spectrum sensing scheme in actual fading communication environment. Meanwhile, in the case of attackers'SNR decreasing, this scheme can decrease the influence to fusion center's integrated decision from attackers. Otherwise, we propose a scheme based on credit mechanism in spectrum distribution, and the system takes the reputation value as the principle of spectrum distribution. Theoretical analysis shows that this scheme can decrease the probability of the unlawfully occupying free spectrum by attackers and enhance the security of the whole system.