Minimization of Age of Information for Satellite-Terrestrial Covert Communication with a Full-Duplex Receiver

This paper investigates the freshness of information for covert communication in a satellite-terrestrial system consisting of a satellite transmitter Alice, a terrestrial full-duplex receiver Bob, and a terrestrial warden Willie. Particularly, Alice tries to transmit covert information to Bob under the detection of Willie, while Bob emits jamming signals to confuse Willie simultaneously. We first provide theoretical modeling for the average age of information (AOI) of Bob and the covert constraint of Willie. Based on the theoretical model, we then drive a optimal transmit power of Alice to minimize the average AoI with the constraint of covertness requirement. Finally, numerical results are presented to verify the theoretical results and to illustrate the impacts of transmit and jamming power on the covertness and average AoI.