Joint Deployment Design and Power Control for UAV-enabled Covert Communications

Unmanned aerial vehicle (UAV) communications have become a promising technique to provide flexible and cost-effective connective service. However, due to its high chance of line-of-sight (LOS) links, UAV communications tend to be detected by the illegal adversaries, which degrades its safety level especially in military scenarios. In this paper, we investigate covert data transmission for UAV communications under the air-to-ground channel model with both LOS and non-line-of-sight components. We aim to maximize the transmit rate of UAV communications while prevent the existence of the transmission from being discovered by the adversary via joint the UAV deployment and transmit power control. We prove the transmit power control and the UAV deployment in the original optimization problem can be decoupled, and derive the closed-form optimal solutions to each sub-problem. Numerical results verify the effectiveness of the proposed algorithm.