Submit to Special Issue Submit Abstract to Special Issue Review for Drones Propose a Special Issue

Journal Menu

Journal Browser

► Journal Browser

Technologies and Applications of UAV Channel Models in Communications and Spectrum Awareness

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Benefits of Publishing in a Special Issue
Published Papers

A special issue of Drones (ISSN 2504-446X). This special issue belongs to the section "Drone Communications".

Deadline for manuscript submissions: 26 March 2025 | Viewed by 12772

Share This Special Issue

Special Issue Editors

Prof. Dr. Qiuming Zhu

E-Mail Website
Guest Editor

Department of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
Interests: UAV channel modeling; UAV channel hardware emulation; spectrum sensing and mapping; UAV communications
Special Issues, Collections and Topics in MDPI journals

Prof. Dr. César Briso-Rodríguez

E-Mail Website
Guest Editor

School of Telecommunication Engineering, Technical University of Madrid, 28031 Madrid, Spain
Interests: channel modeling; UAV technologies; antenna design
Special Issues, Collections and Topics in MDPI journals

Prof. Dr. Mou Chen

E-Mail Website
Guest Editor

Department of Automatic Control, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
Interests: control systems engineering; electrical engineering; aerospace engineering
Special Issues, Collections and Topics in MDPI journals

Prof. Dr. Zhenyu Na

E-Mail Website
Guest Editor

School of Information Science and Technology, Dalian Maritime University, Dalian 116026, China
Interests: space-air-ground networks; UAV Communications; MEC; AI based communications
Special Issues, Collections and Topics in MDPI journals

Dr. Kai Mao

E-Mail Website
Guest Editor

College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China
Interests: UAV Channel sounding; UAV channel modeling; radar sensing

Special Issue Information

Dear Colleagues,

Unmanned Aerial Vehicles (UAVs) have become significant tools in various domains, including communication, spectrum sensing, and environmental monitoring. To ensure robust data transmission in these applications, a deep understanding and accurate description of UAV channel models is fundamental for designing a reliable communication system, which can ensure the reliability and stability of UAV-related navigation, remote control, remote sensing, and data transmission. This Special Issue aims to highlight the recent advancements in UAV channel techniques and their applications across diverse disciplines, especially communication and spectrum awareness. Furthermore, this issue is dedicated to promoting a multidisciplinary dialogue among researchers and policymakers, shedding light on future directions in UAV technologies and applications. The focus is on enhancing UAV capabilities for communication and spectrum awareness.

This Special Issue will cover, but is not limited to, the following topics:

Channel sounding technologies and system for A2G scenarios
UAV channel models for mmWave and sub-Terahertz bands.
AI-driven channel modelling technologies.
AI-driven UAV control technologies.
UAV integrated sensing and communication (ISAC) systems.
UAV-aided spectrum sensing and awareness.
UAV mmWave communications technologies.
UAV trajectory planning and optimization.
Other applications of UAV channel model and communication.

We look forward to receiving your original research articles and reviews.

Prof. Dr. Qiuming Zhu
Prof. Dr. César Briso-Rodríguez
Prof. Dr. Mou Chen
Prof. Dr. Zhenyu Na
Dr. Kai Mao
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Drones is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

UAV channel model
UAV channel sounding
UAV ISAC
UAV communication
UAV spectrum sensing
UAV trajectory planning

Benefits of Publishing in a Special Issue

Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Published Papers (10 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

15 pages, 2582 KiB

Open AccessArticle

A Long-Range and Low-Cost Emergency Radio Beacon for Small Drones

by Juana M. Martínez-Heredia, Jorge Olivera, Francisco Colodro, Manuel Bravo and Manuel R. Arahal

Drones 2024, 8(12), 785; https://doi.org/10.3390/drones8120785 - 23 Dec 2024

Viewed by 826

Abstract

The increasing use of unmanned aerial vehicles (UAVs) in the commercial and recreational sectors has led to a heightened demand for effective recovery solutions after a crash, particularly for lightweight drones. This paper presents the development of a long-range and low-cost emergency radio beacon designed specifically for small UAVs. Unlike traditional emergency locator transmitters (ELTs), our proposed beacon addresses the unique needs of UAVs by reducing size, weight, and cost, while maximizing range and power efficiency. The device utilizes a global system for mobile (GSM)-based communication module to transmit location data via short message service (SMS), eliminating the need for specialized receivers and expanding the operational range even in obstacle-rich environments. Additionally, a built-in global navigation satellite system (GNSS) receiver provides precise coordinates, activated only upon impact detection through an accelerometer, thereby saving power during normal operations. Experimental tests confirm the extended range, high precision, and compatibility of the prototype with common mobile networks. Cost-effective and easy to use, this beacon improves UAV recovery efforts by providing reliable localization data to users in real time, thus safeguarding the UAV investment. Full article

(This article belongs to the Special Issue Technologies and Applications of UAV Channel Models in Communications and Spectrum Awareness)

► Show Figures

Figure 1

23 pages, 1529 KiB

Open AccessArticle

Robust Task Offloading and Trajectory Optimization for UAV-Mounted Mobile Edge Computing

by Runhe Wang, Yang Huang, Yiwei Lu, Pu Xie and Qihui Wu

Drones 2024, 8(12), 757; https://doi.org/10.3390/drones8120757 - 14 Dec 2024

Viewed by 569

Abstract

Mobile edge computing (MEC) deployed in unmanned aerial vehicles (UAVs) has shown special strength by enhancing computational capacity and prolonging the battery lives of terrestrial user equipment (UE). Nevertheless, current research lacks studies of robust offloading scheme scheduling and trajectory planning using terrestrial random channels. The state-of-the-art joint task-offloading and trajectory-planning optimization techniques for UAV-mounted MEC are focused on scenarios where only air–ground channels exist rather than time-varying terrestrial channels. By contrast, this paper considers the scenario where both the time-varying/random terrestrial channels and the line-of-sight air–ground channels occur. Aiming at robust resource scheduling for energy-efficient UAV-assisted MEC, we formulate a novel joint optimization of UAV trajectory planning and task offloading, which, however, is highly nonconvex. As a countermeasure, the original optimization is recast as subproblems related to task offloading and trajectory planning and solved by a novel robust iterative optimization algorithm that combines the methods of weighted minimum mean square error, S-procedure, successive convex approximation, etc. Numerical results indicate that, compared to various baselines, the proposed algorithm can effectively reduce energy consumption and optimize the trajectory in the presence of a large number of input tasks. In addition, in terms of stability and effectiveness, the proposed robust iterative optimization algorithm can reduce energy consumption more stably in time-varying/random channels compared to non-robust schemes. Full article

(This article belongs to the Special Issue Technologies and Applications of UAV Channel Models in Communications and Spectrum Awareness)

► Show Figures

Figure 1

22 pages, 3514 KiB

Open AccessArticle

UAV-Mounted RIS-Aided Multi-Target Localization System: An Efficient Sparse-Reconstruction-Based Approach

by Jingjing Li, Jianhui Wang, Weijia Cui and Chunxiao Jian

Drones 2024, 8(11), 694; https://doi.org/10.3390/drones8110694 - 20 Nov 2024

Viewed by 686

Abstract

Unmanned Aerial Vehicle (UAV) technology is increasingly gaining attention in localization systems due to its flexibility and mobility. However, traditional localization techniques often fail in complex environments where line-of-sight paths are obstructed. To address this challenge, this paper presents an innovative UAV-assisted high-precision multi-target localization system. The system utilizes UAVs equipped with Reconfigurable Intelligent Surfaces to create a reflective signal path, allowing a receiver sensor to capture these signals, creating favorable conditions for multi-target localization. Exploiting the sparsity of signals, we introduce a direct positioning algorithm that leverages Atomic Norm Minimization (ANM) to estimate the target’s location. To address the high complexity of traditional ANM methods, we propose a novel Coyote-ANM-based direct localization (CADL) approach. This method combines the coyote optimization algorithm with the alternating direction method of multipliers to achieve high-accuracy positioning with reduced computational complexity. Simulation results across various signal-to-noise ratio scenarios demonstrate that the proposed algorithm significantly improves localization accuracy, achieving lower root mean square error values and faster execution times compared to traditional methods. Full article

(This article belongs to the Special Issue Technologies and Applications of UAV Channel Models in Communications and Spectrum Awareness)

► Show Figures

Figure 1

21 pages, 2928 KiB

Open AccessArticle

Robust Multi-UAV Cooperative Trajectory Planning and Power Control for Reliable Communication in the Presence of Uncertain Jammers

by Fan Wang, Zhiqiang Zhang, Lingyun Zhou, Tao Shang and Rongqing Zhang

Drones 2024, 8(10), 558; https://doi.org/10.3390/drones8100558 - 8 Oct 2024

Viewed by 791

Abstract

Unmanned aerial vehicles (UAVs) have become a promising application for future communication and spectrum awareness due to their favorable features such as low cost, high mobility, and ease of deployment. Nevertheless, the jamming resistance appears to be a new challenge in multi-UAV cooperative communication scenarios. This paper focuses on designing trajectory planning and power allocation for efficient control and reliable communication in a ground control unit (GCU)-controlled UAV network, where the GCU coordinates multi-UAV systems to execute tasks amidst multiple jammers with imperfect location and power information. Specifically, this paper formulates a nonconvex semi-infinite optimization problem to maximize the average worst-case signal-to-interference-plus-noise ratio (SINR) among multiple UAVs by designing robust flight paths and power control strategy under stringent energy and mobility constraints. To efficiently address this issue, this paper proposes a powerful iterative algorithm utilizing the S-procedure and the successive convex approximation (SCA) method. Extensive simulations validate the effectiveness of the proposed strategy. Full article

(This article belongs to the Special Issue Technologies and Applications of UAV Channel Models in Communications and Spectrum Awareness)

► Show Figures

Figure 1

16 pages, 1699 KiB

Open AccessArticle

Characteristics Analysis and Modeling of Integrated Sensing and Communication Channel for Unmanned Aerial Vehicle Communications

by Xinru Li, Yu Liu, Xinrong Zhang, Yi Zhang, Jie Huang and Ji Bian

Drones 2024, 8(10), 538; https://doi.org/10.3390/drones8100538 - 1 Oct 2024

Viewed by 1113

Abstract

As an important part of 6th generation (6G) communication, integrated sensing and communication (ISAC) for unmanned aerial vehicle (UAV) communication has attracted more and more attention. The UAV ISAC channel model considering the space-time evolution of joint and shared clusters is the basis of UAV ISAC system design and network evaluation. This paper introduces the UAV ISAC channel characteristics analysis and modeling method. In the UAV ISAC network, the channel consists of a communication channel and a sensing channel. A joint channel parameter is a combination of all (communication and sensing) multiple path component (MPC) parameter sets, while a shared path is the intersection of the communication path and sensing path that have some of the same MPC parameters. Based on the data collected from a ray-tracing (RT) UAV-to-ground scenario, the joint paths and shared paths of ISAC channels are clustered. Then, by introducing the occurrence and disappearance of clusters based on the birth–death (B–D) process, the space-time evolution of different clusters is described, and the influence of the addition of sensing clusters and the change in flight altitude on the B–D process is explored. Finally, the effects of the sensing cluster and flight altitude on the UAV ISAC channel characteristics, including the angle, time–varying characteristics, and sharing degree (SD), are analyzed. The related UAV ISAC channel characteristics analysis can provide reference for the future development of UAV ISAC systems. Full article

(This article belongs to the Special Issue Technologies and Applications of UAV Channel Models in Communications and Spectrum Awareness)

► Show Figures

Figure 1

19 pages, 5025 KiB

Open AccessArticle

Measurement-Based Tapped Delay Line Channel Modeling for Fixed-Wing Unmanned Aerial Vehicle Air-to-Ground Communications at S-Band

by Yue Lyu, Yuanfeng He, Zhiwei Liang, Wei Wang, Junyi Yu and Dan Shi

Drones 2024, 8(9), 492; https://doi.org/10.3390/drones8090492 - 17 Sep 2024

Viewed by 1149

Abstract

Fixed-wing unmanned aerial vehicles (UAVs) are widely considered as a vital candidate of aerial base station in beyond Fifth Generation (B5G) systems. Accurate knowledge of air-to-ground (A2G) wireless propagation is important for A2G communication system development and testing where, however, there is still a lack of A2G wideband channel models for such a purpose. In this paper, we present a wideband fixed-wing UAV-based A2G channel measurement campaign at 2.7 GHz, and consider typical flight phases, based on which a wide-sense stationary uncorrelated scattering (WSSUS)-based tapped delay line (TDL) wideband channel model is proposed. Parameters of individual channel taps are analyzed in terms of gain, amplitude distribution, Rice factor and delay-Doppler spectrum. It is shown that UAV flight phases significantly influence the channel tap parameters. Particularly, the “Bell”-type spectrum is found to be the most suitable model for the delay-Doppler spectrum under various flight scenarios for A2G propagation. The proposed channel model can provide valuable assistance and guidance for UAV communication system evaluation and network planning. Full article

(This article belongs to the Special Issue Technologies and Applications of UAV Channel Models in Communications and Spectrum Awareness)

► Show Figures

Figure 1

22 pages, 893 KiB

Open AccessFeature PaperArticle

Unlicensed Spectrum Access and Performance Analysis for NR-U/WiGig Coexistence in UAV Communication Systems

by Zhenzhen Hu, Yong Xu, Yonghong Deng and Zhongpei Zhang

Drones 2024, 8(9), 439; https://doi.org/10.3390/drones8090439 - 28 Aug 2024

Viewed by 992

Abstract

Unmanned aerial vehicles (UAVs) are extensively employed in pursuit, rescue missions, and agricultural applications. These operations necessitate substantial data and video transmission, requiring significant spectral resources. The unlicensed millimeter wave (mmWave) spectrum, especially in the 60 GHz frequency band, offers promising potential for UAV communications. However, WiGig users are the incumbent users of the 60 GHz unlicensed spectrum. Therefore, to ensure fair coexistence between UAV-based new radio-unlicensed (NR-U) users and WiGig users, unlicensed spectrum-sharing strategies need to be meticulously designed. Due to the beam directionality of the NR-U system, traditional listen-before-talk (LBT) spectrum sensing strategies are no longer effective in NR-U/WiGig systems. To address this, we propose a new cooperative unlicensed spectrum sensing strategy based on mmWave beamforming direction. In this strategy, UAV and WiGig users cooperatively sense the unlicensed spectrum and jointly decide on the access strategy. Our analysis shows that the proposed strategy effectively resolves the hidden and exposed node problems associated with traditional LBT strategies. Furthermore, we consider the sensitivity of mmWave to obstacles and analyze the effects of these obstacles on the spectrum-sharing sensing scheme. We examine the unlicensed spectrum access probability and network throughput under blockage scenarios. Simulation results indicate that although obstacles can attenuate the signal, they positively impact unlicensed spectrum sensing. The presence of obstacles can increase spectrum access probability by about 60% and improve system capacity by about 70%. Full article

(This article belongs to the Special Issue Technologies and Applications of UAV Channel Models in Communications and Spectrum Awareness)

► Show Figures

Figure 1

19 pages, 6305 KiB

Open AccessArticle

Deep Reinforcement Learning-Based 3D Trajectory Planning for Cellular Connected UAV

by Xiang Liu, Weizhi Zhong, Xin Wang, Hongtao Duan, Zhenxiong Fan, Haowen Jin, Yang Huang and Zhipeng Lin

Drones 2024, 8(5), 199; https://doi.org/10.3390/drones8050199 - 15 May 2024

Cited by 6 | Viewed by 1866

Abstract

To address the issue of limited application scenarios associated with connectivity assurance based on two-dimensional (2D) trajectory planning, this paper proposes an improved deep reinforcement learning (DRL) -based three-dimensional (3D) trajectory planning method for cellular unmanned aerial vehicles (UAVs) communication. By considering the 3D space environment and integrating factors such as UAV mission completion time and connectivity, we develop an objective function for path optimization and utilize the advanced dueling double deep Q network (D3QN) to optimize it. Additionally, we introduce the prioritized experience replay (PER) mechanism to enhance learning efficiency and expedite convergence. In order to further aid in trajectory planning, our method incorporates a simultaneous navigation and radio mapping (SNARM) framework that generates simulated 3D radio maps and simulates flight processes by utilizing measurement signals from the UAV during flight, thereby reducing actual flight costs. The simulation results demonstrate that the proposed approach effectively enable UAVs to avoid weak coverage regions in space, thereby reducing the weighted sum of flight time and expected interruption time. Full article

(This article belongs to the Special Issue Technologies and Applications of UAV Channel Models in Communications and Spectrum Awareness)

► Show Figures

Figure 1

22 pages, 1272 KiB

Open AccessArticle

A Novel UAV Air-to-Air Channel Model Incorporating the Effect of UAV Vibrations and Diffuse Scattering

by Wenzhe Qi, Ji Bian, Zili Wang and Wenzhao Liu

Drones 2024, 8(5), 194; https://doi.org/10.3390/drones8050194 - 12 May 2024

Cited by 1 | Viewed by 1778

Abstract

In this paper, we propose a geometric channel model for air-to-air (A2A) unmanned aerial vehicle (UAV) communication scenarios. The model is established by incorporating line-of-sight, specular reflection, and diffuse scattering components, and it can capture the impacts of UAV vibrations induced by the propeller’s rotation. Based on UAV heights and ground scatterer density, a closed-form expression is derived to jointly capture the zenith and azimuth angular distributions of diffuse rays. The power of diffuse rays is modeled according to the grazing angle of the rays and the electrical properties and roughness of the ground materials. Key statistics, including the temporal autocorrelation function, spatial cross-correlation function, Doppler power spectrum density, and coherence time are derived, providing an in-depth understanding of the time-variant characteristics of the channel. The results indicate that the presented model is capable of capturing certain A2A channel characteristics, which align with the corresponding theoretical analysis. The findings suggest that the scattering effect of the A2A channel is significantly influenced by the altitude of the UAV. Additionally, it is shown that UAV vibrations can introduce extra Doppler frequencies, notably decreasing the temporal correlation and coherence time of the channel. This effect is more prominent when the system operates at high-frequency bands. The effectiveness of the presented model is confirmed through a comparison of its statistics with those of an existing model and with available measurement data. Full article

(This article belongs to the Special Issue Technologies and Applications of UAV Channel Models in Communications and Spectrum Awareness)

► Show Figures

Figure 1

16 pages, 4877 KiB

Open AccessArticle

Channel Knowledge Map Construction Based on a UAV-Assisted Channel Measurement System

by Yanheng Qiu, Xiaomin Chen, Kai Mao, Xuchao Ye, Hanpeng Li, Farman Ali, Yang Huang and Qiuming Zhu

Drones 2024, 8(5), 191; https://doi.org/10.3390/drones8050191 - 11 May 2024

Cited by 1 | Viewed by 1748

Abstract

With the fast development of unmanned aerial vehicles (UAVs), reliable UAV communication is becoming increasingly vital. The channel knowledge map (CKM) is a crucial bridge connecting the environment and the propagation channel that may visually depict channel characteristics. This paper presents a comprehensive scheme based on a UAV-assisted channel measurement system for constructing the CKM in real-world scenarios. Firstly, a three-dimensional (3D) CKM construction scheme for real-world scenarios is provided, which involves channel knowledge extraction, mapping, and completion. Secondly, an algorithm of channel knowledge extraction and completion is proposed. The sparse channel knowledge is extracted based on the sliding correlation and constant false alarm rate (CFAR) approaches. The 3D Kriging interpolation is used to complete the sparse channel knowledge. Finally, a UAV-assisted channel measurement system is developed and CKM measurement campaigns are conducted in campus and farmland scenarios. The path loss (PL) and root mean square delay spread (RMS-DS) are measured at different heights to determine CKMs. The measured and analyzed results show that the proposed construction scheme can effectively and accurately construct the CKMs in real-world scenarios. Full article

(This article belongs to the Special Issue Technologies and Applications of UAV Channel Models in Communications and Spectrum Awareness)

► Show Figures

Journal Menu

Journal Browser

Technologies and Applications of UAV Channel Models in Communications and Spectrum Awareness

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (10 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI