Research On Optimization Technology Of Cooperative Spectrum Sensing With Malicious Nodes

Cognitive radio technology is one of the important technologies to solve the problem of spectrum scarcity at the present stage. Spectrum sensing technology as the core of cognitive radio technology, the accuracy of spectrum sensing process will directly affect the utilization of the spectrum, so it is very important to ensure the accuracy of spectrum sensing process. There are a lot of factors that affect the spectrum sensing process. In comparison, the existence of malicious nodes is the biggest threat, because we can not accurately locate the position of malicious nodes, effectively detect and remove malicious nodes. In this paper, we focus on analyzing the attack modes of malicious nodes in the cooperative spectrum sensing process, and for the spectrum sensing data falsification attack to do the following research:By improving the crowd internal trust mechanism, we propose a segmented trust value update and defense scheme after considering a more practical cognitive radio network, where malicious users are capable to camouflage themselves. First, we choose slow growth and fast recovery of trust update mechanism, define the energy interval, and then determine which energy interval the reporting energy value of the node belongs to, and finally reduce the malicious node trust value by periodic dynamically updating the trust value table, warn malicious and urge the poor performance node to improve their sensing efficiency. Respectively, which the sensor nodes using two spectrum access modes of the overlay and interweave, the simulation analysis using Monte Carlo method is given to show the effectively of defense malicious attack, guarantee the network performance and throughput.