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Search Results (398)

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Keywords = beyond 5G communication

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20 pages, 1023 KiB  
Article
Joint Optimization of Radio and Computational Resource Allocation in Uplink NOMA-Based Remote State Estimation
by Rongzhen Li and Lei Xu
Sensors 2025, 25(15), 4686; https://doi.org/10.3390/s25154686 - 29 Jul 2025
Viewed by 152
Abstract
In industrial wireless networks beyond 5G and toward 6G, combining uplink non-orthogonal multiple access (NOMA) with the Kalman filter (KF) effectively reduces interruption risks and transmission delays in remote state estimation. However, the complexity of wireless environments and concurrent multi-sensor transmissions introduce significant [...] Read more.
In industrial wireless networks beyond 5G and toward 6G, combining uplink non-orthogonal multiple access (NOMA) with the Kalman filter (KF) effectively reduces interruption risks and transmission delays in remote state estimation. However, the complexity of wireless environments and concurrent multi-sensor transmissions introduce significant interference and latency, impairing the KF’s ability to continuously obtain reliable observations. Meanwhile, existing remote state estimation systems typically rely on oversimplified wireless communication models, unable to adequately handle the dynamics and interference in realistic network scenarios. To address these limitations, this paper formulates a novel dynamic wireless resource allocation problem as a mixed-integer nonlinear programming (MINLP) model. By jointly optimizing sensor grouping and power allocation—considering sensor available power and outage probability constraints—the proposed scheme minimizes both estimation outage and transmission delay. Simulation results demonstrate that, compared to conventional approaches, our method significantly improves transmission reliability and KF estimation performance, thus providing robust technical support for remote state estimation in next-generation industrial wireless networks. Full article
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24 pages, 4549 KiB  
Review
Research on Tbps and Kilometer-Range Transmission of Terahertz Signals
by Jianjun Yu and Jiali Chen
Micromachines 2025, 16(7), 828; https://doi.org/10.3390/mi16070828 - 20 Jul 2025
Viewed by 537
Abstract
THz communication stands as a pivotal technology for 6G networks, designed to address the critical challenge of data demands surpassing current microwave and millimeter-wave (mmWave) capabilities. However, realizing Tbps and kilometer-range transmission confronts the “dual attenuation dilemma” comprising severe free-space path loss (FSPL) [...] Read more.
THz communication stands as a pivotal technology for 6G networks, designed to address the critical challenge of data demands surpassing current microwave and millimeter-wave (mmWave) capabilities. However, realizing Tbps and kilometer-range transmission confronts the “dual attenuation dilemma” comprising severe free-space path loss (FSPL) (>120 dB/km) and atmospheric absorption. This review comprehensively summarizes our group′s advancements in overcoming fundamental challenges of long-distance THz communication. Through systematic photonic–electronic co-optimization, we report key enabling technologies including photonically assisted THz signal generation, polarization-multiplexed multiple-input multiple-output (MIMO) systems with maximal ratio combining (MRC), high-gain antenna–lens configurations, and InP amplifier systems for complex weather resilience. Critical experimental milestones encompass record-breaking 1.0488 Tbps throughput using probabilistically shaped 64QAM (PS-64QAM) in the 330–500 GHz band; 30.2 km D-band transmission (18 Gbps with 543.6 Gbps·km capacity–distance product); a 3 km fog-penetrating link at 312 GHz; and high-sensitivity SIMO-validated 100 Gbps satellite-terrestrial communication beyond 36,000 km. These findings demonstrate THz communication′s viability for 6G networks requiring extreme-capacity backhaul and ultra-long-haul connectivity. Full article
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20 pages, 5781 KiB  
Article
Performance Evaluation of Uplink Cell-Free Massive MIMO Network Under Weichselberger Rician Fading Channel
by Birhanu Dessie, Javed Shaikh, Georgi Iliev, Maria Nenova, Umar Syed and K. Kiran Kumar
Mathematics 2025, 13(14), 2283; https://doi.org/10.3390/math13142283 - 16 Jul 2025
Viewed by 315
Abstract
Cell-free massive multiple-input multiple-output (CF M-MIMO) is one of the most promising technologies for future wireless communication such as 5G and beyond fifth-generation (B5G) networks. It is a type of network technology that uses a massive number of distributed antennas to serve a [...] Read more.
Cell-free massive multiple-input multiple-output (CF M-MIMO) is one of the most promising technologies for future wireless communication such as 5G and beyond fifth-generation (B5G) networks. It is a type of network technology that uses a massive number of distributed antennas to serve a large number of users at the same time. It has the ability to provide high spectral efficiency (SE) as well as improved coverage and interference management, compared to traditional cellular networks. However, estimating the channel with high-performance, low-cost computational methods is still a problem. Different algorithms have been developed to address these challenges in channel estimation. One of the high-performance channel estimators is a phase-aware minimum mean square error (MMSE) estimator. This channel estimator has high computational complexity. To address the shortcomings of the existing estimator, this paper proposed an efficient phase-aware element-wise minimum mean square error (PA-EW-MMSE) channel estimator with QR decomposition and a precoding matrix at the user side. The closed form uplink (UL) SE with the phase MMSE and proposed estimators are evaluated using MMSE combining. The energy efficiency and area throughput are also calculated from the SE. The simulation results show that the proposed estimator achieved the best SE, EE, and area throughput performance with a substantial reduction in the complexity of the computation. Full article
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20 pages, 3269 KiB  
Article
Simulation Investigation of Quantum FSO–Fiber System Using the BB84 QKD Protocol Under Severe Weather Conditions
by Meet Kumari and Satyendra K. Mishra
Photonics 2025, 12(7), 712; https://doi.org/10.3390/photonics12070712 - 14 Jul 2025
Viewed by 308
Abstract
In response to the increasing demands for reliable, fast, and secure communications beyond 5G scenarios, the high-capacity networks have become a focal point. Quantum communication is at the forefront of this research, offering unmatched throughput and security. A free space optics (FSO) communication [...] Read more.
In response to the increasing demands for reliable, fast, and secure communications beyond 5G scenarios, the high-capacity networks have become a focal point. Quantum communication is at the forefront of this research, offering unmatched throughput and security. A free space optics (FSO) communication system integrated with fiber-end is designed and investigated using the Bennett–Brassard 1984 quantum key distribution (BB84-QKD) protocol. Simulation results show that reliable transmission can be achieved over a 10–15 km fiber length with a signal power of −19.54 dBm and high optical-to-signal noise of 72.28–95.30 dB over a 550 m FSO range under clear air, haze, fog, and rain conditions at a data rate of 1 Gbps. Also, the system using rectilinearly and circularly polarized signals exhibits a Stokes parameter intensity of −4.69 to −35.65 dBm and −7.7 to −35.66 dBm Stokes parameter intensity, respectively, over 100–700 m FSO range under diverse weather conditions. Likewise, for the same scenario, an FSO range of 100 m incorporating 2.5–4 mrad beam divergence provides the Stokes power intensity of −6.03 to −11.1 dBm and −9.04 to −14.12 dBm for rectilinearly and circularly polarized signals, respectively. Moreover, compared to existing works, this work allows faithful and secure signal transmission in free space, considering FSO–fiber link losses. Full article
(This article belongs to the Section Quantum Photonics and Technologies)
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25 pages, 2908 KiB  
Article
Secure and Scalable File Encryption for Cloud Systems via Distributed Integration of Quantum and Classical Cryptography
by Changjong Kim, Seunghwan Kim, Kiwook Sohn, Yongseok Son, Manish Kumar and Sunggon Kim
Appl. Sci. 2025, 15(14), 7782; https://doi.org/10.3390/app15147782 - 11 Jul 2025
Viewed by 427
Abstract
We propose a secure and scalable file-encryption scheme for cloud systems by integrating Post-Quantum Cryptography (PQC), Quantum Key Distribution (QKD), and Advanced Encryption Standard (AES) within a distributed architecture. While prior studies have primarily focused on secure key exchange or authentication protocols (e.g., [...] Read more.
We propose a secure and scalable file-encryption scheme for cloud systems by integrating Post-Quantum Cryptography (PQC), Quantum Key Distribution (QKD), and Advanced Encryption Standard (AES) within a distributed architecture. While prior studies have primarily focused on secure key exchange or authentication protocols (e.g., layered PQC-QKD key distribution), our scheme extends beyond key management by implementing a distributed encryption architecture that protects large-scale files through integrated PQC, QKD, and AES. To support high-throughput encryption, our proposed scheme partitions the target file into fixed-size subsets and distributes them across slave nodes, each performing parallel AES encryption using a locally reconstructed key from a PQC ciphertext. Each slave node receives a PQC ciphertext that encapsulates the AES key, along with a PQC secret key masked using QKD based on the BB84 protocol, both of which are centrally generated and managed by the master node for secure coordination. In addition, an encryption and transmission pipeline is designed to overlap I/O, encryption, and communication, thereby reducing idle time and improving resource utilization. The master node performs centralized decryption by collecting encrypted subsets, recovering the AES key, and executing decryption in parallel. Our evaluation using a real-world medical dataset shows that the proposed scheme achieves up to 2.37× speedup in end-to-end runtime and up to 8.11× speedup in encryption time over AES (Original). In addition to performance gains, our proposed scheme maintains low communication cost, stable CPU utilization across distributed nodes, and negligible overhead from quantum key management. Full article
(This article belongs to the Special Issue AI-Enabled Next-Generation Computing and Its Applications)
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41 pages, 2392 KiB  
Review
How Beyond-5G and 6G Makes IIoT and the Smart Grid Green—A Survey
by Pal Varga, Áron István Jászberényi, Dániel Pásztor, Balazs Nagy, Muhammad Nasar and David Raisz
Sensors 2025, 25(13), 4222; https://doi.org/10.3390/s25134222 - 6 Jul 2025
Viewed by 692
Abstract
The convergence of next-generation wireless communication technologies and modern energy infrastructure presents a promising path toward sustainable and intelligent systems. This survey explores how beyond-5G and 6G communication technologies can support the greening of Industrial Internet of Things (IIoT) systems and smart grids. [...] Read more.
The convergence of next-generation wireless communication technologies and modern energy infrastructure presents a promising path toward sustainable and intelligent systems. This survey explores how beyond-5G and 6G communication technologies can support the greening of Industrial Internet of Things (IIoT) systems and smart grids. It highlights the critical challenges in achieving energy efficiency, interoperability, and real-time responsiveness across different domains. The paper reviews key enablers such as LPWAN, wake-up radios, mobile edge computing, and energy harvesting techniques for green IoT, as well as optimization strategies for 5G/6G networks and data center operations. Furthermore, it examines the role of 5G in enabling reliable, ultra-low-latency data communication for advanced smart grid applications, such as distributed generation, precise load control, and intelligent feeder automation. Through a structured analysis of recent advances and open research problems, the paper aims to identify essential directions for future research and development in building energy-efficient, resilient, and scalable smart infrastructures powered by intelligent wireless networks. Full article
(This article belongs to the Special Issue Feature Papers in the Internet of Things Section 2025)
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26 pages, 389 KiB  
Review
Recent Advancements in Millimeter-Wave Antennas and Arrays: From Compact Wearable Designs to Beam-Steering Technologies
by Faisal Mehmood and Asif Mehmood
Electronics 2025, 14(13), 2705; https://doi.org/10.3390/electronics14132705 - 4 Jul 2025
Viewed by 916
Abstract
Millimeter-wave (mmWave) antennas and antenna arrays have gained significant attention due to their pivotal role in emerging wireless communication, sensing, and imaging technologies. With the rapid deployment of 5G and the transition toward 6G networks, the demand for compact, high-gain, and reconfigurable mmWave [...] Read more.
Millimeter-wave (mmWave) antennas and antenna arrays have gained significant attention due to their pivotal role in emerging wireless communication, sensing, and imaging technologies. With the rapid deployment of 5G and the transition toward 6G networks, the demand for compact, high-gain, and reconfigurable mmWave antennas has intensified. This article highlights recent advancements in mmWave antenna technologies, including hybrid beamforming using phased arrays, dynamic beam-steering enabled by liquid crystal and MEMS-based structures, and high-capacity MIMO architectures. We also examine the integration of metamaterials and metasurfaces for miniaturization and gain enhancement. Applications covered include wearable antennas with low-SAR textile substrates, conformal antennas for UAV-based mmWave relays, and high-resolution radar arrays for autonomous vehicles. The study further analyzes innovative fabrication methods such as inkjet and aerosol jet printing, micromachining, and laser direct structuring, along with advanced materials like Kapton, PDMS, and graphene. Numerical modeling techniques such as full-wave EM simulation and machine learning-based optimization are discussed alongside experimental validation approaches. Beyond communications, we assess mmWave systems for biomedical imaging, security screening, and industrial sensing. Key challenges addressed include efficiency degradation at high frequencies, interference mitigation in dense environments, and system-level integration. Finally, future directions, including AI-driven design automation, intelligent reconfigurable surfaces, and integration with quantum and terahertz technologies, are outlined. This comprehensive synthesis aims to serve as a valuable reference for advancing next-generation mmWave antenna systems. Full article
(This article belongs to the Special Issue Recent Advancements of Millimeter-Wave Antennas and Antenna Arrays)
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29 pages, 3813 KiB  
Article
Addressing Climate Resilience in the African Region: Prioritizing Mental Health and Psychosocial Well-Being in Disaster Preparedness and Response Planning for Mainstream Communities and Migrants
by Belayneh Fentahun Shibesh and Nidhi Nagabhatla
Climate 2025, 13(7), 139; https://doi.org/10.3390/cli13070139 - 3 Jul 2025
Viewed by 589
Abstract
Climate change represents a complex and multifaceted challenge for health systems, particularly in the African region, where the research has predominantly focused on physical health impacts while overlooking critical mental health dimensions. Our central hypothesis is that integrating culturally adapted mental health and [...] Read more.
Climate change represents a complex and multifaceted challenge for health systems, particularly in the African region, where the research has predominantly focused on physical health impacts while overlooking critical mental health dimensions. Our central hypothesis is that integrating culturally adapted mental health and psychosocial support (MHPSS) into climate resilience frameworks and disaster response planning will significantly reduce psychological distress (e.g., anxiety, depression, and trauma) and enhance adaptive capacities among both mainstream and migrant communities in disaster-prone African regions. This rapid review methodology systematically explores the intricate relationships between climate change, mental health, and migration by examining the existing literature and identifying significant information gaps. The key findings underscore the urgent need for targeted research and strategic interventions that specifically address mental health vulnerabilities in the context of climate change. This review highlights how extreme weather events, environmental disruptions, and forced migration create profound psychological stressors that extend beyond immediate physical health concerns. This research emphasizes the importance of developing comprehensive adaptation strategies integrating mental health considerations into broader climate response frameworks. Recommendations emerging from this assessment call for immediate and focused attention on developing specialized research, policies, and interventions that recognize the unique mental health challenges posed by climate change in African contexts. We also note the current limitations in the existing national adaptation plans, which frequently overlook mental health dimensions, thereby underscoring the necessity of a more holistic and nuanced approach to understanding climate change’s psychological impacts. In this exploratory study, we intended to provide a crucial preliminary assessment of the complex intersections between climate change, mental health, and migration, offering valuable insights for policymakers, researchers, and healthcare professionals seeking to develop more comprehensive and responsive strategies in an increasingly challenging environmental landscape. Full article
(This article belongs to the Special Issue Coping with Flooding and Drought)
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20 pages, 2749 KiB  
Article
ROVs Utilized in Communication and Remote Control Integration Technologies for Smart Ocean Aquaculture Monitoring Systems
by Yen-Hsiang Liao, Chao-Feng Shih, Jia-Jhen Wu, Yu-Xiang Wu, Chun-Hsiang Yang and Chung-Cheng Chang
J. Mar. Sci. Eng. 2025, 13(7), 1225; https://doi.org/10.3390/jmse13071225 - 25 Jun 2025
Viewed by 538
Abstract
This study presents a new intelligent aquatic farming surveillance system that tackles real-time monitoring challenges in the industry. The main technical break-throughs of this system are evident in four key aspects: First, it achieves the smooth integration of remotely operated vehicles (ROVs), sensors, [...] Read more.
This study presents a new intelligent aquatic farming surveillance system that tackles real-time monitoring challenges in the industry. The main technical break-throughs of this system are evident in four key aspects: First, it achieves the smooth integration of remotely operated vehicles (ROVs), sensors, and real-time data transmission. Second, it uses a mobile communication architecture with buoy relay stations for distributed edge computing. This design supports future upgrades to Beyond 5G and satellite networks for deep-sea applications. Third, it features a multi-terminal control system that supports computers, smartphones, smartwatches, and centralized hubs, effectively enabling monitoring anytime, anywhere. Fourth, it incorporates a cost-effective modular design, utilizing commercial hardware and innovative system integration solutions, making it particularly suitable for farms with limited resources. The data indicates that the system’s 4G connection is both stable and reliable, demonstrating excellent performance in terms of data transmission success rates, control command response delays, and endurance. It has successfully processed 324,800 data transmission events, thoroughly validating its reliability in real-world production environments. This system integrates advanced technologies such as the Internet of Things, mobile communications, and multi-access control, which not only significantly enhance the precision oversight capabilities of marine farming but also feature a modular design that allows for future expansion into satellite communications. Notably, the system reduces operating costs while simultaneously improving aquaculture efficiency, offering a practical and intelligent solution for small farmers in resource-limited areas. Full article
(This article belongs to the Special Issue Design and Application of Underwater Vehicles)
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12 pages, 272 KiB  
Review
Tools for Diagnosing and Managing Sport-Related Concussion in UK Primary Care: A Scoping Review
by Sachin Bhandari, Soo Yit Gustin Mak, Neil Heron and John Rogers
Sports 2025, 13(7), 201; https://doi.org/10.3390/sports13070201 - 23 Jun 2025
Viewed by 399
Abstract
Background: The UK Department for Digital, Culture, Media, and Sport (DCMS) grassroots concussion guidance, May 2023, advised that all community-based sport-related concussions (SRCs) be diagnosed by a healthcare practitioner. This may require that general practitioners (GPs) diagnose and manage SRCs. Diagnosing SRCs in [...] Read more.
Background: The UK Department for Digital, Culture, Media, and Sport (DCMS) grassroots concussion guidance, May 2023, advised that all community-based sport-related concussions (SRCs) be diagnosed by a healthcare practitioner. This may require that general practitioners (GPs) diagnose and manage SRCs. Diagnosing SRCs in primary care settings in the United Kingdom (UK) presents significant challenges, primarily due to the lack of validated tools specifically designed for general practitioners (GPs). This scoping review aims to identify diagnostic and management tools for SRCs in grassroots sports and primary care settings. Aims: To identify tools that can be used by GPs to diagnose and manage concussions in primary care, both adult and paediatric populations. Design and Methods: A scoping review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScRs). Five databases (MEDLINE, EMBASE, CINAHL, Cochrane Library, Google Scholar) were searched from 1946 to April 2025. Search terms included “concussion”, “primary care”, and “diagnosis”. Studies that discussed SRCs in community or primary care settings were included. Those that exclusively discussed secondary care and elite sports were excluded, as well as non-English studies. Two reviewers independently screened titles, abstracts, and full texts, with a third resolving any disagreements. Data were extracted into Microsoft Excel. Studies were assessed for quality using the Joanna Briggs critical appraisal tools and AGREE II checklist. Results: Of 727 studies, 12 met the inclusion criteria. Identified tools included Sport Concussion Assessment Tool 6 (SCAT6, 10–15 min, adolescent/adults), Sport Concussion Office Assessment Tool 6 (SCOAT6, 45–60 min, multidisciplinary), the Buffalo Concussion Physical Examination (BCPE, 5–6 min, adolescent-focused), and the Brain Injury Screening Tool (BIST, 6 min, ages 8+). As part of BCPE, a separate Telehealth version was developed for remote consultations. SCAT6 and SCOAT6 are designed for healthcare professionals, including GPs, but require additional training and time beyond typical UK consultation lengths (9.2 min). BIST and BCPE show promise but require UK validation. Conclusions: SCAT6, SCOAT6, BIST, and BCPE could enhance SRC care, but their feasibility in UK primary care requires adaptation (e.g., integration with GP IT systems and alignment with NICE guidelines). Further research is required to validate these tools and assess additional training needs. Full article
(This article belongs to the Special Issue Sport-Related Concussion and Head Impact in Athletes)
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40 pages, 3342 KiB  
Article
Enhancing Infotainment Services in Integrated Aerial–Ground Mobility Networks
by Chenn-Jung Huang, Liang-Chun Chen, Yu-Sen Cheng, Ken-Wen Hu and Mei-En Jian
Sensors 2025, 25(13), 3891; https://doi.org/10.3390/s25133891 - 22 Jun 2025
Viewed by 355
Abstract
The growing demand for bandwidth-intensive vehicular applications—particularly ultra-high-definition streaming and immersive panoramic video—is pushing current network infrastructures beyond their limits, especially in urban areas with severe congestion and degraded user experience. To address these challenges, we propose an aerial-assisted vehicular network architecture that [...] Read more.
The growing demand for bandwidth-intensive vehicular applications—particularly ultra-high-definition streaming and immersive panoramic video—is pushing current network infrastructures beyond their limits, especially in urban areas with severe congestion and degraded user experience. To address these challenges, we propose an aerial-assisted vehicular network architecture that integrates 6G base stations, distributed massive MIMO networks, visible light communication (VLC), and a heterogeneous aerial network of high-altitude platforms (HAPs) and drones. At its core is a context-aware dynamic bandwidth allocation algorithm that intelligently routes infotainment data through optimal aerial relays, bridging connectivity gaps in coverage-challenged areas. Simulation results show a 47% increase in average available bandwidth over conventional first-come-first-served schemes. Our system also satisfies the stringent latency and reliability requirements of emergency and live infotainment services, creating a sustainable ecosystem that enhances user experience, service delivery, and network efficiency. This work marks a key step toward enabling high-bandwidth, low-latency smart mobility in next-generation urban networks. Full article
(This article belongs to the Special Issue Sensing and Machine Learning Control: Progress and Applications)
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21 pages, 1329 KiB  
Article
DDPG-Based UAV-RIS Framework for Optimizing Mobility in Future Wireless Communication Networks
by Yasir Ullah, Idris Olalekan Adeoye, Mardeni Roslee, Mohd Azmi Ismail, Farman Ali, Shabeer Ahmad, Anwar Faizd Osman and Fatimah Zaharah Ali
Drones 2025, 9(6), 437; https://doi.org/10.3390/drones9060437 - 15 Jun 2025
Viewed by 501
Abstract
The development of beyond 5G (B5G) future wireless communication networks (FWCN) needs novel solutions to support high-speed, reliable, and low-latency communication. Unmanned aerial vehicles (UAVs) and reconfigurable intelligent surfaces (RISs) are promising techniques that can enhance wireless connectivity in urban environments where tall [...] Read more.
The development of beyond 5G (B5G) future wireless communication networks (FWCN) needs novel solutions to support high-speed, reliable, and low-latency communication. Unmanned aerial vehicles (UAVs) and reconfigurable intelligent surfaces (RISs) are promising techniques that can enhance wireless connectivity in urban environments where tall buildings block line-of-sight (LoS) links. However, existing UAV-assisted communication strategies do not fully address key challenges like mobility management, handover failures (HOFs), and path disorders in dense urban environments. This paper introduces a deep deterministic policy gradient (DDPG)-based UAV-RIS framework to overcome these limitations. The proposed framework jointly optimizes UAV trajectories and RIS phase shifts to improve throughput, energy efficiency (EE), and LoS probability while reducing outage probability (OP) and HOF. A modified K-means clustering algorithm is used to efficiently partition the ground users (GUs) considering the newly added GUs as well. The DDPG algorithm, based on reinforcement learning (RL), adapts UAV positioning and RIS configurations in a continuous action space. Simulation results show that the proposed approach significantly reduces HOF and OP, increases EE, enhances network throughput, and improves LoS probability compared to UAV-only, RIS-only, and without UAV-RIS deployments. Additionally, by dynamically adjusting UAV locations and RIS phase shifts based on GU mobility patterns, the framework further enhances connectivity and reliability. The findings highlight its potential to transform urban wireless communication by mitigating LoS blockages and ensuring uninterrupted connectivity in dense environments. Full article
(This article belongs to the Special Issue UAV-Assisted Mobile Wireless Networks and Applications)
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38 pages, 15283 KiB  
Article
A Fast Convergence Scheme Using Chebyshev Iteration Based on SOR and Applied to Uplink M-MIMO B5G Systems for Multi-User Detection
by Yung-Ping Tu and Guan-Hong Liu
Appl. Sci. 2025, 15(12), 6658; https://doi.org/10.3390/app15126658 - 13 Jun 2025
Viewed by 393
Abstract
Massive multiple input–multiple output (M-MIMO) is a promising and pivotal technology in contemporary wireless communication systems that can effectively enhance link reliability and data throughput, especially in uplink scenarios. Even so, the receiving end requires more computational complexity to reconstitute the signal. This [...] Read more.
Massive multiple input–multiple output (M-MIMO) is a promising and pivotal technology in contemporary wireless communication systems that can effectively enhance link reliability and data throughput, especially in uplink scenarios. Even so, the receiving end requires more computational complexity to reconstitute the signal. This problem has emerged in fourth-generation (4G) MIMO system; with the dramatic increase in demand for devices and data in beyond-5G (B5G) systems, this issue will become yet more obvious. To take into account both complexity and signal-revested capability at the receiver, this study uses the matrix iteration method to avoid the staggering amount of operations produced by the inverse matrix. Then, we propose a highly efficient multi-user detector (MUD) named hybrid SOR-based Chebyshev acceleration (CHSOR) for the uplink of M-MIMO orthogonal frequency-division multiplexing (OFDM) and universal filtered multi-carrier (UFMC) waveforms, which can be promoted to B5G developments. The proposed CHSOR scheme includes two stages: the first consists of successive over-relaxation (SOR) and modified successive over-relaxation (MSOR), combining the advantages of low complexity of both and generating a better initial transmission symbol, iteration matrix, and parameters for the next stage; sequentially, the second stage adopts the low-cost iterative Chebyshev acceleration method for performance refinement to obtain a lower bit error rate (BER). Under constrained evaluation settings, Section (Simulation Results and Discussion) presents the results of simulations performed in MATLAB version R2022a. Results show that the proposed detector can achieve a 91.624% improvement in BER performance compared with Chebyshev successive over-relaxation (CSOR). This is very near to the performance of the minimum mean square error (MMSE) detector and is achieved in only a few iterations. In summary, our proposed CHSOR scheme demonstrates fast convergence compared to previous works and as such possesses excellent BER and complexity performance, making it a competitive solution for uplink M-MIMO B5G systems. Full article
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59 pages, 4517 KiB  
Review
Artificial Intelligence Empowering Dynamic Spectrum Access in Advanced Wireless Communications: A Comprehensive Overview
by Abiodun Gbenga-Ilori, Agbotiname Lucky Imoize, Kinzah Noor and Paul Oluwadara Adebolu-Ololade
AI 2025, 6(6), 126; https://doi.org/10.3390/ai6060126 - 13 Jun 2025
Viewed by 1860
Abstract
This review paper examines the integration of artificial intelligence (AI) in wireless communication, focusing on cognitive radio (CR), spectrum sensing, and dynamic spectrum access (DSA). As the demand for spectrum continues to rise with the expansion of mobile users and connected devices, cognitive [...] Read more.
This review paper examines the integration of artificial intelligence (AI) in wireless communication, focusing on cognitive radio (CR), spectrum sensing, and dynamic spectrum access (DSA). As the demand for spectrum continues to rise with the expansion of mobile users and connected devices, cognitive radio networks (CRNs), leveraging AI-driven spectrum sensing and dynamic access, provide a promising solution to improve spectrum utilization. The paper reviews various deep learning (DL)-based spectrum-sensing methods, highlighting their advantages and challenges. It also explores the use of multi-agent reinforcement learning (MARL) for distributed DSA networks, where agents autonomously optimize power allocation (PA) to minimize interference and enhance quality of service. Additionally, the paper discusses the role of machine learning (ML) in predicting spectrum requirements, which is crucial for efficient frequency management in the fifth generation (5G) networks and beyond. Case studies show how ML can help self-optimize networks, reducing energy consumption while improving performance. The review also introduces the potential of generative AI (GenAI) for demand-planning and network optimization, enhancing spectrum efficiency and energy conservation in wireless networks (WNs). Finally, the paper highlights future research directions, including improving AI-driven network resilience, refining predictive models, and addressing ethical considerations. Overall, AI is poised to transform wireless communication, offering innovative solutions for spectrum management (SM), security, and network performance. Full article
(This article belongs to the Special Issue Artificial Intelligence for Network Management)
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14 pages, 1230 KiB  
Opinion
The Anatomical and Evolutionary Impact of Pain, Pleasure, Motivation, and Cognition: Integrating Energy Metabolism and the Mind–Body BERN (Behavior, Exercise, Relaxation, and Nutrition) Framework
by George B. Stefano, Pascal Buttiker, Maren M. Michaelsen and Tobias Esch
Int. J. Mol. Sci. 2025, 26(12), 5491; https://doi.org/10.3390/ijms26125491 - 8 Jun 2025
Cited by 1 | Viewed by 617
Abstract
In this manuscript, we highlight the evolutionary origins of mitochondria from bacterial endosymbionts and explore their contributions to health, energy metabolism, and neural–immune communication. Mitochondrial adaptability and the roles played by these organelles in promoting oxygen-dependent ATP production provide critical regulation of cognition, [...] Read more.
In this manuscript, we highlight the evolutionary origins of mitochondria from bacterial endosymbionts and explore their contributions to health, energy metabolism, and neural–immune communication. Mitochondrial adaptability and the roles played by these organelles in promoting oxygen-dependent ATP production provide critical regulation of cognition, motivation, and inflammation. Hypoxia has been identified as an important initiator of inflammation, neurodegeneration, and mitochondrial dysfunction, emphasizing the overall importance of oxygen homeostasis to health and well-being. The Behavior, Exercise, Relaxation, and Nutrition framework highlights these observations as tools that can be used to optimize mitochondrial efficiency. Interestingly, mitochondrial dysfunction may also be linked to psychiatric disorders (e.g., schizophrenia), a hypothesis that focuses on energy dynamics, a proposal that may extend our understanding of these disorders beyond traditional neurotransmitter-focused concepts. Collectively, these perspectives underscore the critical contributions of mitochondria to health and disease and offer a novel framework that may help to explain the connections featured in mind–body medicine. Full article
(This article belongs to the Section Molecular Endocrinology and Metabolism)
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