On IRS-Aided Covert Communications of D2D-Enabled Cellular Networks

This paper investigates covert communications in device-to-device (D2D)-enabled networks, where a D2D transmitter intends to covertly transmit message to its receiver with the aid of an intelligent reflecting surface (IRS). To model the fundamental covert rate performance, we first derive the outage probabilities for D2D and cellular links. Then, we formulate the covert rate maximization as an optimization problem subject to the constraints of the transmit powers of D2D and cellular transmitters as well as the IRS reflection coefficient. We further solve the optimization problem. Finally, the simulation results are presented to illustrate the effectiveness of IRS-aided D2D covert communications in such networks with severe shadow fading.