Secure Cognitive Communication via Cooperative Jamming

Nowadays, unmanned aerial vehicles (UAVs) are widely used to ensure the security of wireless communications. In this paper, we propose a cooperative jamming scheme to secure cognitive radio (CR) networks. In the proposed scheme, the source UAV transmits confidential information to ground users. Because of the presence of an eavesdropper (Eve), the UAV jammer sends friendly interference signals to protect private information. It should be noted that the primary transmission of CR networks cannot be disturbed. Therefore, we formulate an optimization problem to maximize the average secrecy rate under the constraint of primary interference. Since trajectory planning and power control are coupled, we propose the alternative optimization (AO) algorithm. Furthermore, as the sub-problems are non-convex, sequential convex approximation (SCA) algorithm is a good choice, which makes our scheme converge to the Karush-Kuhn-Tucker point. Simulation results show that the joint optimization of power and trajectory of our proposed scheme is effective for improving the systematic secure performance.