Resource Allocation for Covert Wireless Transmission in UAV Communication Networks

Abstract

In this paper, we propose an improper Gaussian signaling (IGS) empowered covert communication strategy in unmanned air vehicle (UAV) assisted communication systems. The ground user (Alice) covertly transmits confidential messages to the UAV amounted based station (Bob) by superimposing over an overt channel, which is licensed to an existing communication system. To alleviate the inner-system interference caused by the superimposed waveforms, we design the IGS as the waveform of the covert communication system and the proper Gaussian signaling (PGS) as the waveform of the existing communication system. We derive closed-form expressions for the outage prob-ability of the overt and covert transmission links, respectively. Moreover, we formulate a joint transmit power and IGS factor optimization problem to maximize the outage performance of the covert communication system constraining the covertness requirement and quality of service of the existing communication system. The optimal solution is derived by leveraging the mono-tonic properties of objective function and constraints. Finally, simulation results are provided to verify the effectiveness of the proposed covert communication strategy.