Dynamic Double Threshold Spectrum Sensing Algorithm Based on Block Chain

The realization of spectrum sensing is becoming more and more possible with the development of technologies such as artificial intelligence and software radio. While we are paying attention to its performance, we cannot ignore the security problems it faces. This paper proposes an optimization scheme to defend against spectrum sensing data falsification (SSDF) attacks based on the double threshold energy detection and block chain technology. First, to reduce the impact of noise uncertainty on spectrum sensing results, we assume that the judgment threshold value will be dynamically determined according to the actual SNR of the receiver; Secondly, the block chain is introduced to consider as a spectrum sharing platform, and build the reputation classification mechanism for the cognitive users (CUs). We use a reward and penalty mechanism similar to the bitcoin system for CU's trust value statistics. Only users in the reliable zone can participate in sensing fusion; the rest will be in the waiting or discarding zone. We use MATLAB to carry out simulation experiments on the proposed algorithm. The experimental results show that the proposed algorithm can achieve the probability of false alarm to 0.1, the probability of detection to 0.93, and effectively avoid the interference of malicious users.