The present invention discloses a device-to-device
covert communication system assisted by a
drone and an intelligent reflecting surface, establishes a
drone and intelligent reflecting surface UIRS joint-assisted D2D
covert communication model, including communication links between various entities, calculates the average minimum error detection probability and the maximum communication rate; the sender sends a covert
signal to the UIRS, and the UIRS forwards it to the
receiver. Among them, the UIRS changes the angles of the corresponding incident covert
signal and the reflected covert
signal through its constituent elements; the spectrum-sharing cellular user sends a cellular signal to the
base station, and at the same time the
base station sends an interference signal, introducing an
uncertainty factor at the
receiver of the eavesdropper Willie to achieve the covertness of the UIRS joint-assisted D2D
communication link; the eavesdropper Willie monitors whether the UIRS joint-assisted D2D
communication link transmits a covert signal; the covertness is measured by the average minimum error detection probability; under the multiple constraints of satisfying the average minimum error detection probability, the
cellular communication link
outage probability, the transmission power, and the transmission power of the interference signal, etc., the maximum communication rate of the UIRS joint-assisted D2D
communication link is obtained, and the communication rate of the
system is effectively improved under the joint assistance of the
drone and the intelligent reflecting surface UIRS.