533 research outputs found
A Survey of Physical Layer Security Techniques for 5G Wireless Networks and Challenges Ahead
Physical layer security which safeguards data confidentiality based on the
information-theoretic approaches has received significant research interest
recently. The key idea behind physical layer security is to utilize the
intrinsic randomness of the transmission channel to guarantee the security in
physical layer. The evolution towards 5G wireless communications poses new
challenges for physical layer security research. This paper provides a latest
survey of the physical layer security research on various promising 5G
technologies, including physical layer security coding, massive multiple-input
multiple-output, millimeter wave communications, heterogeneous networks,
non-orthogonal multiple access, full duplex technology, etc. Technical
challenges which remain unresolved at the time of writing are summarized and
the future trends of physical layer security in 5G and beyond are discussed.Comment: To appear in IEEE Journal on Selected Areas in Communication
RIS-assisted Scheduling for High-Speed Railway Secure Communications
With the rapid development of high-speed railway systems and railway wireless
communication, the application of ultra-wideband millimeter wave band is an
inevitable trend. However, the millimeter wave channel has large propagation
loss and is easy to be blocked. Moreover, there are many problems such as
eavesdropping between the base station (BS) and the train. As an emerging
technology, reconfigurable intelligent surface (RIS) can achieve the effect of
passive beamforming by controlling the propagation of the incident
electromagnetic wave in the desired direction.We propose a RIS-assisted
scheduling scheme for scheduling interrupted transmission and improving quality
of service (QoS).In the propsed scheme, an RIS is deployed between the BS and
multiple mobile relays (MRs). By jointly optimizing the beamforming vector and
the discrete phase shift of the RIS, the constructive interference between
direct link signals and indirect link signals can be achieved, and the channel
capacity of eavesdroppers is guaranteed to be within a controllable range.
Finally, the purpose of maximizing the number of successfully scheduled tasks
and satisfying their QoS requirements can be practically realized. Extensive
simulations demonstrate that the proposed scheme has superior performance
regarding the number of completed tasks and the system secrecy capacity over
four baseline schemes in literature.Comment: 15 pages, 10 figures, to appear in IEEE Transactions on Vehicular
Technolog
Intelligent Reflective Surface Deployment in 6G: A Comprehensive Survey
Intelligent reflecting surfaces (IRSs) are considered a promising technology
that can smartly reconfigure the wireless environment to enhance the
performance of future wireless networks. However, the deployment of IRSs still
faces challenges due to highly dynamic and mobile unmanned aerial vehicle (UAV)
enabled wireless environments to achieve higher capacity. This paper sheds
light on the different deployment strategies for IRSs in future terrestrial and
non-terrestrial networks. Specifically, in this paper, we introduce key
theoretical concepts underlying the IRS paradigm and discuss the design aspects
related to the deployment of IRSs in 6G networks. We also explore
optimization-based IRS deployment techniques to improve system performance in
terrestrial and aerial IRSs. Furthermore, we survey model-free reinforcement
learning (RL) techniques from the deployment aspect to address the challenges
of achieving higher capacity in complex and mobile IRS-assisted UAV wireless
systems. Finally, we highlight challenges and future research directions from
the deployment aspect of IRSs for improving system performance for the future
6G network.Comment: 16 pages, 3 Figures, 7 table
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