Proactive Eavesdropping in UAV-Aided Suspicious Communication Systems

This paper considers a new wireless information surveillance scenario, where a legitimate monitor tries to eavesdrop on the suspicious messages sent by an unmanned aerial vehicle aided suspicious transmitter. By using the characteristic of the suspicious system, we propose an effective proactive jamming scheme to maximize the achievable eavesdropping rate. A successive convex approximation based iterative algorithm is first developed to solve the original non-convex optimization problem. Based on this result, the eavesdropping rate maximization problem is then solved by applying the one-dimensional search method. Moreover, we also study the special case of two suspicious receivers for gaining more useful insights on designing the optimal jamming transmission strategy. Numerical results show that the proposed proactive jamming approach can significantly enhance the achievable eavesdropping rate compared to the reference scheme.