IRS-Assisted Secure UAV Transmission via Joint Trajectory and Beamforming Design

Abstract

Despite the wide utilization of unmanned aerial vehicles (UAVs), UAV communications are susceptible to eavesdropping due to air-ground line-of-sight channels. Intelligent reflecting surface (IRS) is capable of reconfiguring the propagation environment, and thus is an attractive solution for integrating with UAV to facilitate the security in wireless networks. In this paper, we investigate the secure transmission design for an IRSassisted UAV network in the presence of an eavesdropper. With the aim at maximizing the average secrecy rate, the trajectory of UAV, the transmit beamforming, and the phase shift of IRS are jointly optimized. To address this sophisticated problem, we decompose it into three sub-problems and resort to an iterative algorithm to solve them alternately. First, we derive the closedform solution to the active beamforming. Then, with the optimal transmit beamforming, the passive beamforming optimization problem of fractional programming is transformed into corresponding parametric sub-problems. Moreover, the successive convex approximation is applied to deal with the non-convex UAV trajectory optimization problem by reformulating a convex problem which serves as a lower bound for the original one. Simulation results validate the effectiveness of the proposed scheme and the performance improvement achieved by the joint trajectory and beamforming design.

Robust Trajectory and Communication Design in IRS-Assisted UAV Communication under Malicious Jamming

“…Thanks to the appealing advantages, IRS has been exploited as a promising choice for improving the performance of UAV communication for combating security threats. In [10], the average secrecy rate was maximized by jointly optimizing the UAV trajectory, the transmit beamforming and the phase shift of IRS. In [11] and [12], the UAV equipped with one IRS serves as a passive relay is proposed to maximize the secrecy rate of the system.…”

Graph Layer Security: Encrypting Information via Common Networked Physics

“…Physical layer security (PLS) has been proposed in recent years as a way to overcome many of the aforementioned challenges, which can be categorised as key-less PLS [ 8 , 9 ] and physical layer secret key generation (PL-SKG) [ 10 , 11 , 12 ]. Key-less PLS leverages the superiority of legitimate channels over wiretap ones, and tries to maximise the secrecy rate or signal to interference plus noise ratio (SINR) by steering the variables, e.g., beamforming vectors [ 13 ], trajectory of autonomous system [ 14 ], and even the phases of a reconfigurable intelligent surface (RIS) [ 15 ]. One challenge lies in that the superiority of the legitimate channel may not be always satisfied.…”

Channel Estimation with Simultaneous Reflecting and Sensing Reconfigurable Intelligent Metasurfaces

“…By properly adjusting the reflection properties of the metamaterial elements, RISs can constructively strengthen/destructively weaken the desired/undesired signals at the target receiver(s). This ability of RISs has been exploited in various promising communication systems, such as multi-user Multiple-Input Multiple-Outputs (MIMOs) communications [7], [8], simultaneous wireless information and power transfer systems [9], [10], and physical-layer security [11],…”