31 research outputs found
When UAV Meets IRS: Expanding Air-Ground Networks via Passive Reflection
Thanks to their flexibility and mobility, unmanned aerial vehicles (UAVs) have been widely applied in wireless networks. However, UAV communications may suffer from blockage and eavesdropping in practical scenarios due to the complex environment. Taking the recent advances in intelligent reflecting surface (IRS) to reconfigure the propagation environments, in this article, we employ IRS to enhance the performance of UAV-aided air-ground networks. First, we overview the combination of UAV and IRS, by introducing the diverse applications of IRS and the appealing advantages of UAV, and highlighting the benefits of combining them. Then, we investigate two case studies where the UAV trajectory, the transmit beamforming and the IRS passive beamforming are jointly optimized. In the first case study, by equipping the IRS on a UAV, the average achievable rate of the relaying network is maximized. In the second one, the IRS is deployed to assist the UAV-ground communication while combating the adversarial eavesdropper. Simulation results are provided to demonstrate the performance enhancement resulting from combining UAV and IRS in air-ground networks. Finally, we shed light on some challenging issues to be resolved for practical implementations in this direction
Energy-Aware Resource Allocation and Trajectory Design for UAV-Enabled ISAC
In this paper, we investigate joint resource allocation and trajectory design
for multi-user multi-target unmanned aerial vehicle (UAV)-enabled integrated
sensing and communication (ISAC). To improve sensing accuracy, the UAV is
forced to hover during sensing.~In particular, we jointly optimize the
two-dimensional trajectory, velocity, downlink information and sensing
beamformers, and sensing indicator to minimize the average power consumption of
a fixed-altitude UAV, while considering the quality of service of the
communication users and the sensing tasks. To tackle the resulting non-convex
mixed integer non-linear program (MINLP), we exploit semidefinite relaxation,
the big-M method, and successive convex approximation to develop an alternating
optimization-based algorithm.~Our simulation results demonstrate the
significant power savings enabled by the proposed scheme compared to two
baseline schemes employing heuristic trajectories.Comment: This paper has been accepted for presentation at IEEE GLOBECOM 202
IRS-assisted UAV Communications: A Comprehensive Review
Intelligent reflecting surface (IRS) can smartly adjust the wavefronts in
terms of phase, frequency, amplitude and polarization via passive reflections
and without any need of radio frequency (RF) chains. It is envisaged as an
emerging technology which can change wireless communication to improve both
energy and spectrum efficiencies with low energy consumption and low cost. It
can intelligently configure the wireless channels through a massive number of
cost effective passive reflecting elements to improve the system performance.
Similarly, unmanned aerial vehicle (UAV) communication has gained a viable
attention due to flexible deployment, high mobility and ease of integration
with several technologies. However, UAV communication is prone to security
issues and obstructions in real-time applications. Recently, it is foreseen
that UAV and IRS both can integrate together to attain unparalleled
capabilities in difficult scenarios. Both technologies can ensure improved
performance through proactively altering the wireless propagation using smart
signal reflections and maneuver control in three dimensional (3D) space. IRS
can be integrated in both aerial and terrene environments to reap the benefits
of smart reflections. This study briefly discusses UAV communication, IRS and
focuses on IRS-assisted UAC communications. It surveys the existing literature
on this emerging research topic and highlights several promising technologies
which can be implemented in IRS-assisted UAV communication. This study also
presents several application scenarios and open research challenges. This study
goes one step further to elaborate research opportunities to design and
optimize wireless systems with low energy footprint and at low cost. Finally,
we shed some light on future research aspects for IRS-assisted UAV
communication
IRS-aided UAV for Future Wireless Communications: A Survey and Research Opportunities
Both unmanned aerial vehicles (UAVs) and intelligent reflecting surfaces
(IRS) are gaining traction as transformative technologies for upcoming wireless
networks. The IRS-aided UAV communication, which introduces IRSs into UAV
communications, has emerged in an effort to improve the system performance
while also overcoming UAV communication constraints and issues. The purpose of
this paper is to provide a comprehensive overview of IRSassisted UAV
communications. First, we provide five examples of how IRSs and UAVs can be
combined to achieve unrivaled potential in difficult situations. The
technological features of the most recent relevant researches on IRS-aided UAV
communications from the perspective of the main performance criteria, i.e.,
energy efficiency, security, spectral efficiency, etc. Additionally, previous
research studies on technology adoption as machine learning algorithms. Lastly,
some promising research directions and open challenges for IRS-aided UAV
communication are presented
A Comprehensive Overview on 5G-and-Beyond Networks with UAVs: From Communications to Sensing and Intelligence
Due to the advancements in cellular technologies and the dense deployment of
cellular infrastructure, integrating unmanned aerial vehicles (UAVs) into the
fifth-generation (5G) and beyond cellular networks is a promising solution to
achieve safe UAV operation as well as enabling diversified applications with
mission-specific payload data delivery. In particular, 5G networks need to
support three typical usage scenarios, namely, enhanced mobile broadband
(eMBB), ultra-reliable low-latency communications (URLLC), and massive
machine-type communications (mMTC). On the one hand, UAVs can be leveraged as
cost-effective aerial platforms to provide ground users with enhanced
communication services by exploiting their high cruising altitude and
controllable maneuverability in three-dimensional (3D) space. On the other
hand, providing such communication services simultaneously for both UAV and
ground users poses new challenges due to the need for ubiquitous 3D signal
coverage as well as the strong air-ground network interference. Besides the
requirement of high-performance wireless communications, the ability to support
effective and efficient sensing as well as network intelligence is also
essential for 5G-and-beyond 3D heterogeneous wireless networks with coexisting
aerial and ground users. In this paper, we provide a comprehensive overview of
the latest research efforts on integrating UAVs into cellular networks, with an
emphasis on how to exploit advanced techniques (e.g., intelligent reflecting
surface, short packet transmission, energy harvesting, joint communication and
radar sensing, and edge intelligence) to meet the diversified service
requirements of next-generation wireless systems. Moreover, we highlight
important directions for further investigation in future work.Comment: Accepted by IEEE JSA
Secure and Reliable Resource Allocation and Caching in Aerial-Terrestrial Cloud Networks (ATCNs)
Aerial-terrestrial cloud networks (ATCNs), global integration of air and ground communication systems, pave a way for a large set of applications such as surveillance, on-demand transmissions, data-acquisition, and navigation. However, such networks suffer from crucial challenges of secure and reliable resource allocation and content-caching as the involved entities are highly dynamic and there is no fine-tuned strategy to accommodate their connectivity. To resolve this quandary, cog-chain, a novel paradigm for secure and reliable resource allocation and content-caching in ATCNs, is presented. Various requirements, key concepts, and issues with ATCNs are also presented along with basic concepts to establish a cog-chain in ATCNs. Feed and fetch modes are utilized depending on the involved entities and caching servers. In addition, a cog-chain communication protocol is presented which avails to evaluate the formation of a virtual cog-chain between the nodes and the content-caching servers. The efficacy of the proposed solution is demonstrated through consequential gains observed for signaling overheads, computational time, reliability, and resource allocation growth. The proposed approach operates with the signaling overheads ranging between 30.36 and 303.6 bytes?hops/sec and the formation time between 186 and 195 ms. Furthermore, the overall time consumption is 83.33% lower than the sequential-verification model and the resource allocation growth is 27.17% better than the sequential-verification model. - 2019 IEEE.This work was supported in part by the Institute for Information and Communications Technology Promotion (IITP) grant through the Korean Government (MSIT) (Rule Specification-Based Misbehavior Detection for IoT-Embedded Cyber-Physical Systems) under Grant 2017-0-00664, and in part by the Soonchunhyang University Research Fund.Scopu
Intelligent-Reflecting-Surface-Assisted UAV Communications for 6G Networks
In 6th-Generation (6G) mobile networks, Intelligent Reflective Surfaces
(IRSs) and Unmanned Aerial Vehicles (UAVs) have emerged as promising
technologies to address the coverage difficulties and resource constraints
faced by terrestrial networks. UAVs, with their mobility and low costs, offer
diverse connectivity options for mobile users and a novel deployment paradigm
for 6G networks. However, the limited battery capacity of UAVs, dynamic and
unpredictable channel environments, and communication resource constraints
result in poor performance of traditional UAV-based networks. IRSs can not only
reconstruct the wireless environment in a unique way, but also achieve wireless
network relay in a cost-effective manner. Hence, it receives significant
attention as a promising solution to solve the above challenges. In this
article, we conduct a comprehensive survey on IRS-assisted UAV communications
for 6G networks. First, primary issues, key technologies, and application
scenarios of IRS-assisted UAV communications for 6G networks are introduced.
Then, we put forward specific solutions to the issues of IRS-assisted UAV
communications. Finally, we discuss some open issues and future research
directions to guide researchers in related fields
Secrecy analysis of UAV-based mmWave relaying network
Employing unmanned aerial vehicles (UAVs) in millimeter-wave (mmWave) networks as relays has emerged as an appealing solution to assist remote or blocked communication nodes. In this case, the network security becomes a great challenge due to the presence of malicious eavesdroppers. In this paper, we perform a secrecy analysis for a UAV-based mmWave relaying network. We first investigate the relaying scheme without jamming where the UAV decodes and forwards the information from the source to the destination with malicious eavesdropping. Furthermore, to enhance the secrecy performance, we propose a cooperative jamming scheme via utilizing the destination and an external UAV to cooperatively disrupt the eavesdroppers at the two stages of relaying, respectively. Using the probability of line-of-sight (LoS) between the UAV and ground nodes, the three-dimensional (3D) antenna gain, and the Nakagami-m small-scale fading model, the secrecy outage probability (SOP) of the two schemes with and without jamming is analyzed. Closed-form expressions for the SOP of the two schemes are obtained by employing the Gauss-Chebyshev quadrature. Simulation results are presented to validate the theoretical expressions of SOP and to show the effectiveness of the proposed schemes