A Comparative Secrecy Study of Flying and Ground Eavesdropping in UAV Based Communication Systems

Abstract

In this paper, we study the strictly positive secrecy outage probability (SOP) and the ergodic secrecy capacity of a wiretap unmanned aerial vehicle (UAV) system where a UAV transmitter (Alice) is trying to send a message to a ground receiver (Bob) while an eavesdropper (Eve) is attempting to eavesdrop on the legitimate communication link. We study the performance of the system in two cases, first, when Eve is on the ground and an Air-to-Ground channel model is adopted between Alice, Bob and Eve. In the second case, Eve is a UAV drone that is located at the same altitude as Alice and the channel between Alice and Eve follows an Air-to-Air channel model. We derive closed form expressions of the SOP and ergodic secrecy capacity for the two scenarios. Simulation results verify the analytical derivations, where the results highlight the importance of the derived secrecy metrics, especially the impact of the distance between Alice and Eve on the overall performance. - 2019 IEEE.