Direction Modulation Design for UAV Assisted by IRS with discrete phase shift

TL;DR

This paper proposes a joint optimization scheme for IRS-assisted UAV communication to enhance security and transmission rate by manipulating digital weights, UAV positioning, and IRS phase shifts, including novel algorithms for phase shift optimization.

Contribution

It introduces new algorithms (CE-VT and BCD-VT) for optimizing IRS phase shifts in UAV communications, improving security and transmission performance.

Findings

CE-VT and BCD-VT algorithms outperform traditional methods.

The optimization scheme effectively enhances UAV communication security.

Numerical results confirm the scheme's effectiveness.

Abstract

As a physical layer security technology, directional modulation (DM) can be combined with intelligent reflect-ing surface (IRS) to improve the security of drone communications. In this paper, a directional modulation scheme assisted by the IRS is proposed to maximize the transmission rate of unmanned aerial vehicle (UAV) secure communication. Specifically, with the assistance of the IRS, the UAV transmits legitimate information and main-tains its constellation pattern at the location of legitimate users on the ground, while the constellation pattern is disrupted at the eavesdropper's location. In order to solve the joint optimization problem of digital weight coefficients, UAV position, and IRS discrete phase shift, firstly, the digital weight vector and UAV position are optimized through power minimization. Secondly, three methods are proposed to optimize IRS phase shift, namely vector trajectory (VT) method, cross entropy vector trajectory (CE-VT) algorithm, and block coordinate descent vector trajectory (BCD-VT) algorithm. Compared to traditional cross entropy (CE) methods and block coordinate descent (BCD) methods, the proposed CE-VT and BCD-VT algorithms can improve transmission rate performance. The numerical results validate the effectiveness of the optimization scheme in IRS assisted UAV communication.