| 1. |
- Barros da Silva Jr., José Mairton, Dr. 1990-, et al.
(författare)
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Full-Duplex and Dynamic-TDD: Pushing the Limits of Spectrum Reuse in Multi-Cell Communications
- 2021
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Ingår i: IEEE wireless communications. - : IEEE Communications Society. - 1536-1284 .- 1558-0687. ; 28:1, s. 44-50
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Tidskriftsartikel (refereegranskat)abstract
- Although in cellular networks full duplex and dynamic time-division duplexing promise increased spectrum efficiency, their potential is so far challenged by increased interference. While previous studies have shown that self-interference can be suppressed to a sufficient level, we show that the cross-link interference for both duplexing modes, especially from base station to base station, is the remaining challenge in multi-cell networks, restricting the uplink performance. Using beamforming techniques of low complexity, we show that this interference can be mitigated, and that full duplex and dynamic time-division duplexing can substantially increase the capacity of multi-cell networks. Our results suggest that if we can control the cross-link interference in full duplex, we can almost double the multi-cell network capacity as well as user throughput. Therefore, the techniques in this article have the potential to enable a smooth introduction of full duplex into cellular systems.
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| 2. |
- Basharat, Sarah, et al.
(författare)
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Reconfigurable Intelligent Surface-Assisted Backscatter Communication : A New Frontier for Enabling 6G IoT Networks
- 2022
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Ingår i: IEEE wireless communications. - 1536-1284 .- 1558-0687. ; 29:6, s. 96-103
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Tidskriftsartikel (refereegranskat)abstract
- Backscatter Communication (BackCom), which is based on passive reflection and modulation of an incident radio-frequency (RF) wave, has emerged as a cutting-edge technological paradigm for self-sustainable Internet-of-things (IoT). Nevertheless, contemporary BackCom systems are limited to short-range and low data rate applications only, rendering them insufficient on their own to support pervasive connectivity among the massive number of IoT devices. Meanwhile, wireless networks are rapidly evolving toward the smart radio paradigm. In this regard, reconfigurable intelligent surfaces (RISs) have come to the forefront to transform the wireless propagation environment into a fully controllable and customizable space in a cost-effective and energy-efficient manner. Targeting the sixth-generation (6G) horizon, we anticipate the integration of RISs into BackCom systems as a new frontier for enabling 6G IoT networks. In this article, for the first time in the open literature, we provide a tutorial overview of RIS-assisted BackCom (RIS-BackCom) systems. Specifically, we introduce the three different variants of RIS-Back- Com and identify the potential improvements that can be achieved by incorporating RISs into Back- Com systems. In addition, owing to the unrivaled effectiveness of non-orthogonal multiple access (NOMA), we present a case study on a RIS-assisted NOMA-enhanced BackCom system. Finally, we outline the way forward for translating this disruptive concept into real-world applications.
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| 3. |
- Basharat, S., et al.
(författare)
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Reconfigurable Intelligent Surfaces : Potentials, Applications, and Challenges for 6G Wireless Networks
- 2021
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Ingår i: IEEE wireless communications. - : Institute of Electrical and Electronics Engineers Inc.. - 1536-1284 .- 1558-0687.
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Tidskriftsartikel (refereegranskat)abstract
- Reconfigurable intelligent surfaces (RISs), with the potential to realize smart radio environments, have emerged as an energy-efficient and a cost-effective technology to support the services and demands foreseen for coming decades. By leveraging a large number of low-cost passive reflecting elements, RISs introduce a phase-shift in the impinging signal to create a favorable propagation channel between the transmitter and the receiver. In this article, we provide a tutorial overview of RISs for sixth-generation (6G) wireless networks. Specifically, we present a comprehensive discussion on performance gains that can be achieved by integrating RISs with emerging communication technologies. We address the practical implementation of RIS-assisted networks and expose the crucial challenges, including the RIS reconfiguration, deployment and size optimization, and channel estimation. Furthermore, we explore the integration of RIS and non-orthogonal multiple access (NOMA) under imperfect channel state information (CSI). Our numerical results illustrate the importance of better channel estimation in RIS-assisted networks and indicate the various factors that impact the size of RIS. Finally, we present promising future research directions for realizing RIS-assisted networks in 6G communication. IEEE
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| 4. |
- Chen, Hui, 1992, et al.
(författare)
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6G Localization and Sensing in the Near Field: Features, Opportunities, and Challenges
- 2024
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Ingår i: IEEE Wireless Communications. - 1536-1284 .- 1558-0687. ; In press
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Tidskriftsartikel (refereegranskat)abstract
- The far-field channel model has historically been used in wireless communications due to the simplicity of mathematical modeling and convenience for algorithm design. With the need for high data rates, low latency, and ubiquitous connectivity in the sixth generation (6G) of communication systems, new technology enablers such as extremely large antenna arrays (ELAAs), reconfigurable intelligent surfaces (RISs), and distributed multiple-input-multiple-output (D-MIMO) systems will be adopted. These enablers not only aim to improve communication services but also have an impact on localization and sensing (L&S), which are expected to be fundamentally built-in functionalities in future wireless systems. Despite appearing in different scenarios and supporting different frequency bands, such enablers share the so-called near-field (NF) features, which will provide extra geometric information conducive to L&S. In this work, we describe the NF features, namely, the spherical wave model, spatial non-stationarity, and beam squint effect. After discussing how L&S see NF differently from communication, the opportunities and open research challenges are provided.
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| 5. |
- Chen, Hao, et al.
(författare)
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Satellite-Based Computing Networks with Federated Learning
- 2022
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Ingår i: IEEE wireless communications. - : Institute of Electrical and Electronics Engineers (IEEE). - 1536-1284 .- 1558-0687. ; 29:1, s. 78-84
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Tidskriftsartikel (refereegranskat)abstract
- Driven by the ever increasing penetration and proliferation of data-driven applications, a new generation of wireless communication, the sixth generation (6G) mobile system enhanced by artificial intelligence, has attracted substantial research interests. Among various candidate technologies of 6G, low Earth orbit (LEO) satellites have appealing characteristics of ubiquitous wireless access. However, the costs of satellite communication (SatCom) are still high, relative to their counterparts of ground mobile networks. To support massively interconnected devices with intelligent adaptive learning and reduce expensive traffic in SatCom, we propose federated learning (FL) in LEO-based satellite communication networks. We first review the state-of-the-art LEO-based SatCom and related machine learning (ML) techniques, and then analyze four possible ways of combining ML with satellite networks. The learning performance of the proposed strategies is evaluated by simulation and results reveal that FL-based computing networks improve the performance of communication overheads and latency. Finally, we discuss future research topics along this research direction.
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| 6. |
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| 7. |
- Guo, Zhiwei, et al.
(författare)
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Deep Federated Learning Enhanced Secure POI Microservices for Cyber-Physical Systems
- 2022
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Ingår i: IEEE wireless communications. - : Institute of Electrical and Electronics Engineers (IEEE). - 1536-1284 .- 1558-0687. ; 29:2, s. 22-29
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Tidskriftsartikel (refereegranskat)abstract
- An essential consideration in cyber-physical systems (CPS) is the ability to support secure communication services, such as points of interest (POI) microservices. Existing approaches to support secure POI microservices generally rely on anonymity and/or differential privacy technologies. There are, however, a number of known limitations with such approaches. Hence, this work presents a deep-federated-learning-based framework for securing POI microservices in CPS. In order to enhance data security, the system architecture is designed to isolate the cloud center from accessing user data on edge nodes, and an interactive training mechanism is introduced between the cloud center and edge nodes. Specifically, edge nodes pre-train reliable deep-learning-based models for users, and the cloud server coordinates parameter updating via federated learning. The connected and isolated structure between cloud center and edges facilitates deep federated learning. Finally, we implement and evaluate the performance of our proposed approach using two real-world POI-related datasets. The results show that our proposed approach achieves optimal scheduling performance and demonstrates its practical utility.
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| 8. |
- Liu, Liang, et al.
(författare)
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MASSIVE MACHINE-TYPE COMMUNICATIONS FOR IOT
- 2021
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Ingår i: IEEE wireless communications. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 1536-1284 .- 1558-0687. ; 28:4, s. 56-56
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
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| 9. |
- Masouros, Christos, et al.
(författare)
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Guest Editorial: Integrated Sensing and Communications for 6G
- 2023
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Ingår i: IEEE Wireless Communications. - 1536-1284 .- 1558-0687. ; 30:1, s. 14-15
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- 6G networks have been envisioned as key enablers for numerous emerging applications, including smart cities and homes, intelligently connected vechiles, smart manufactoring, and industrial Internet-of-Things (IoT). These applications require both extreme wireless connectivity as well as highly accurate and reliable sensing capability. Indeed, among many 6G visions, a common theme is that sensing will play a more significant role than ever before. By equipping wireless systems with the sensing functionality, 6G networks will go beyond classical communication and provide ubiquitous sensing services to measure, or to image, surrounding environments. This sensing functionality and the corresponding ability of the network to collect sensory data from the environment are seen as the foundation for building intelligence in the future smart world. Toward that end, there is a strong need to jointly design sensing and communication operations in 6G networks, which motivates the recent research of Integrated Sensing and Communications (ISAC).
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| 10. |
- Nikonowicz, Jakub, et al.
(författare)
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Indoor Positioning in 5G-Advanced : Challenges and Solution toward Centimeter- Level Accuracy with Carrier Phase Enhancements
- 2024
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Ingår i: IEEE wireless communications. - : Institute of Electrical and Electronics Engineers (IEEE). - 1536-1284 .- 1558-0687. ; 31:4, s. 268-275
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Tidskriftsartikel (refereegranskat)abstract
- Like robust connectivity, precise positioning is evolving into an innovative component of 5G service offerings for industrial use-cases and verticals with challenging indoor radio environments. Therefore, the 3GPP Rel-16 standard has been a tipping point in specifying critical innovations, followed by enhancements in Rel-17 and Rel-18. In this article, we discuss the 5G positioning framework, measurements, and procedures before shifting the focus to recently identified carrier-phase (CP) measurements in Rel-18 as a complementary measure for time- and angular-based positioning methods. We discuss the associated challenges and potential solutions for exploiting CP, including integer ambiguity, multipath sensitivity, and signaling aspects. Furthermore, we study the ways in which phase-continuous reference signaling can counter noisy phase measurements using realistic simulations to achieve centimeter-level accuracy in indoor factory (InF) scenarios.
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