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Joint Beamforming and Phase Shift Design for Hybrid IRS and UAV-Aided Directional Modulation Networks

Dong, Rongen, He, Hangjia, Shu, Feng, Zhang, Qi, Chen, Riqing, Yan, Shihao, Wang, Jiangzhou (2023) Joint Beamforming and Phase Shift Design for Hybrid IRS and UAV-Aided Directional Modulation Networks. Drones, 7 (6). Article Number 364. E-ISSN 2504-446X. (doi:10.3390/drones7060364) (KAR id:101570)


Recently, intelligent reflecting surfaces (IRSs) and unmanned aerial vehicles (UAVs) have been integrated into wireless communication systems to enhance the performance of air–ground transmission. To balance performance, cost, and power consumption well, a hybrid IRS and UAV-assisted directional modulation (DM) network is investigated in this paper in which the hybrid IRS consisted of passive and active reflecting elements. We aimed to maximize the achievable rate by jointly designing the beamforming and phase shift matrix (PSM) of the hybrid IRS subject to the power and unit-modulus constraints of passive IRS phase shifts. To solve the non-convex optimization problem, a high-performance scheme based on successive convex approximation and fractional programming (FP) called the maximal signal-to-noise ratio (SNR)-FP (Max-SNR-FP) is proposed. Given its high complexity, we propose a low-complexity maximal SNR-equal amplitude reflecting (EAR) (Max-SNR-EAR) scheme based on the maximal signal-to-leakage-noise ratio method, and the criteria of phase alignment and EAR. Given that the active and passive IRS phase shift matrices of both schemes are optimized separately, to investigate the effect of jointly optimizing them to improve the achievable rate, a maximal SNR majorization-minimization (MM) (Max-SNR-MM) scheme using the MM criterion to design the IRS PSM is proposed. Simulation results show that the rates harvested by the three proposed methods were slightly lower than those of the active IRS with higher power consumption, which were 35% higher than those of no IRS and random phase IRS, while passive IRS achieved only about a 17% rate gain over the latter. Moreover, compared with the Max-SNR-FP, the proposed Max-SNR-EAR and Max-SNR-MM methods caused obvious complexity degradation at the price of slight performance loss.

Item Type: Article
DOI/Identification number: 10.3390/drones7060364
Uncontrolled keywords: hybrid intelligent reflecting surface, unmanned aerial vehicle, directional modulation, phase shift, beamforming
Subjects: T Technology > TA Engineering (General). Civil engineering (General)
Divisions: Divisions > Division of Computing, Engineering and Mathematical Sciences > School of Engineering and Digital Arts
Funders: National Natural Science Foundation of China (
SWORD Depositor: JISC Publications Router
Depositing User: JISC Publications Router
Date Deposited: 08 Jun 2023 13:32 UTC
Last Modified: 04 Mar 2024 15:38 UTC
Resource URI: (The current URI for this page, for reference purposes)

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