Covert Communications against UAV Surveillance via Probabilistic Transmission

In this work, we investigate covert communications against UAV surveillance, where a sensor tries to transmit information to its receiver covertly by exploiting the noise uncertainty at the UAV. Specifically, the sensor can adjust its transmit power and transmission probability to make a balance between the communication covertness and quality. To measure the communication covertness and quality, we analytically derive the detection error probability and the effective covert rate, respectively. It is interesting to find that the optimal transmission probability is a moderate value rather than 1/2 to maximize the communication covertness. Then, we formulate an optimization problem to maximize the communication covertness under the requirement of the communication quality. At last, we give the joint optimization solution of the transmit power and probability at the sensor, which can be used as the guidance of the parameter setting in practice.