Improving Security in Cooperative Communication Networks by Using UAV-assisted Proactive Eavesdropping

In this paper, an unmanned aerial vehicles (UAV)s is used to improve the physical layer security of a cooperative communication network. More specifically, in the proposed surveillance system a UAV acts as a legitimate monitor to eavesdrop on a dubious decode-and-forward relaying communication. To maximize the effective eavesdropping rate, two adaptive scenarios are suggested for the legitimate monitor: scenario I) jammer-eavesdropper, and scenario II) eavesdropper-helper/eavesdropper-eavesdropper/ eavesdropper-jammer. For each strategy, the received signal-to-interference-plus-noise ratios SINRs are derived. Numerical results reveal that the proposed strategies achieve better performance than intuitive benchmark schemes. Moreover, as a simple criterion, UAV should employ scenario II when it is close to source, and employ scenario I when it is close to relay.