Rotatable Antenna Array Enabled UAV mmWave Massive MIMO Communication

Zhang X, Xiang L, Wang J, Gao X, Ng DWK, Schober R (2025)

Publication Type: Journal article

Publication year: 2025

Journal

IEEE Transactions on Communications Institute of Electrical and Electronics Engineers (IEEE)

DOI: 10.1109/TCOMM.2025.3622962

Abstract

Unmanned aerial vehicle (UAV) assisted millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO) is a transformative technology for realizing seamless air-space-ground integrated communications in future wireless networks. Most existing studies on UAV MIMO assume isotropic antennas with fixed orientations. However, since practical mmWave antennas inherently exhibit directional radiation patterns, fixed antenna orientations (FAOs) may cause some users to fall within the sidelobe regions of the directional antennas and experience severe signal attenuation. Moreover, FAOs may lead to highly correlated user channels and excessive inter-user interference. To address these issues, we introduce a novel scheme employing a rotatable antenna array (RAA) at the UAV base station (BS) while explicitly accounting for the antenna radiation pattern for enhanced mmWave massive MIMO transmission. The RAA can not only steer the main lobe of the directional antennas towards the users to enhance the signal transmission, but also effectively mitigate channel correlations among users by adjusting the steering vectors, unleashing additional degrees of freedom (DoFs) for precise precoding to enhance the transmission efficiency. We first consider a finite number of antennas at the UAV-BS and propose an efficient method to jointly design the hybrid digital-analog precoding and the RAA orientation under the quality-of-service (QoS) constraints. Then we theoretically reveal that, unlike FAOs, the RAA enables the channel vectors of different users to be asymptotically orthogonal. This allows us to derive the asymptotically optimal hybrid precoder in closed form and further develop a low-complexity approach to determine the optimal RAA orientation. Simulation results show that our proposed RAA enabled transmission scheme significantly outperforms FAOs, and our asymptotic design achieves near-optimal performance with minimal complexity.

Authors with CRIS profile

Robert Schober Lehrstuhl für Digitale Übertragung (IDC)

Involved external institutions

Southeast University / 东南大学 CN China (CN) University of New South Wales (UNSW) AU Australia (AU) Technische Universität Darmstadt DE Germany (DE)

How to cite

APA:

Zhang, X., Xiang, L., Wang, J., Gao, X., Ng, D.W.K., & Schober, R. (2025). Rotatable Antenna Array Enabled UAV mmWave Massive MIMO Communication. IEEE Transactions on Communications. https://doi.org/10.1109/TCOMM.2025.3622962

MLA:

Zhang, Xuzhong, et al. "Rotatable Antenna Array Enabled UAV mmWave Massive MIMO Communication." IEEE Transactions on Communications (2025).

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