IRS Assisted Covert Communication of UAV through Phase Shift and Trajectory Optimization

The unmanned aerial vehicle (UAV) combined with intelligent reflecting surface (IRS) could greatly improve the electromagnetic propagation environment to enhance the quality of the wireless communication. However, with the development of the technology, the issue of information security in wireless communication has become very important. Therefore, a covert communication scheme for UAV assisted by IRS is proposed in this paper, aiming to maximize the transmission rate. The scheme achieves covertness by utilizing a full-duplex receiver to interfere with the eavesdropper. The optimal detection threshold and minimum error detection probability are derived, which could represent the worst-case situation for the legitimate transmission. Subsequently, adhering to the covertness requirement, the UAV's trajectory and IRS's phase shift are optimized to maximize the covert transmission rate. Numerical results demonstrate the effectiveness of the proposed covert communication scheme.