Performance Analysis for UAV-Jammer Aided Covert Communication

This paper investigates the performance analysis for a novel covert communication system, where a friendly UAV-jammer is used to protect the covert transmission from Alice to Bob against the eavesdropping from Dave. In particular, by exploiting the spatial diversity, the UAV can emit artificial noise (AN) to complicate the noise uncertainty at Dave. In this letter, two scenarios are studied, where the channels from Alice to Bob and Dave experience 1) AWGN and 2) Nakagami- $m$ fading. The closed-form expression for privacy rate expression under AWGN is derived, where evaluating the condition for achieving a positive gain of using UAV-jammer. Furthermore, under the Nakagami- $m$ fading scenario, an approximate expression of ergodic privacy rate is obtained by using Taylor expansion. In the end, simulation results show that significant performance gain in terms of privacy rate can be achieved by employing UAV-jammer for covert communication.