| 1. |
- 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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| 2. |
- Davide, Dardari, et al.
(författare)
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Innovative Signal Processing Techniques for Wireless Positioning
- 2012
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Ingår i: Satellite and Terrestrial Radio Positioning Techniques, Davide Dardari, Emanuela Falletti, and Marco Luise, editors. Oxford, Academic Press. - 9780123820846 ; , s. 207-315
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 3. |
- De Lima, Carlos, et al.
(författare)
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Convergent Communication, Sensing and Localization in 6G Systems: An Overview of Technologies, Opportunities and Challenges
- 2021
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Ingår i: IEEE Access. - 2169-3536 .- 2169-3536. ; 9, s. 26902-26925
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Forskningsöversikt (refereegranskat)abstract
- Herein, we focus on convergent 6G communication, localization and sensing systems by identifying key technology enablers, discussing their underlying challenges, implementation issues, and recommending potential solutions. Moreover, we discuss exciting new opportunities for integrated localization and sensing applications, which will disrupt traditional design principles and revolutionize the way we live, interact with our environment, and do business. Regarding potential enabling technologies, 6G will continue to develop towards even higher frequency ranges, wider bandwidths, and massive antenna arrays. In turn, this will enable sensing solutions with very fine range, Doppler, and angular resolutions, as well as localization to cm-level degree of accuracy. Besides, new materials, device types, and reconfigurable surfaces will allow network operators to reshape and control the electromagnetic response of the environment. At the same time, machine learning and artificial intelligence will leverage the unprecedented availability of data and computing resources to tackle the biggest and hardest problems in wireless communication systems. As a result, 6G will be truly intelligent wireless systems that will provide not only ubiquitous communication but also empower high accuracy localization and high-resolution sensing services. They will become the catalyst for this revolution by bringing about a unique new set of features and service capabilities, where localization and sensing will coexist with communication, continuously sharing the available resources in time, frequency, and space. This work concludes by highlighting foundational research challenges, as well as implications and opportunities related to privacy, security, and trust.
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| 4. |
- Duran, Mauricio A. Caceres, et al.
(författare)
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Terrestrial Network-Based Positioning and Navigation
- 2012
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Ingår i: Satellite and Terrestrial Radio Positioning Techniques, Davide Dardari, Emanuela Falletti, and Marco Luise, editors. Oxford, Academic Press. - 9780123820846 ; , s. 75-153
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Gholami, Mohammad Reza, 1976, et al.
(författare)
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Static positioning using UWB range measurements
- 2010
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Ingår i: Future Network & Mobile Summit 2010, Florence, Italy, June 16-18.
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Konferensbidrag (refereegranskat)abstract
- The performance of several existing and partly new algorithms for positioningof sensor node based on distance estimate is compared when the distanceestimates are obtained from a measurement campaign. The distance estimates arebased on time-of-arrival measurements done by ultrawideband devices in an indooroffice environment. Two different positioning techniques are compared: statisticaland geometrical. In statistical category, distributed weighted-multidimensional scaling(dwMDS), least squares, and sum product algorithm are evaluated and in geometricaltechnique projections approach and outer approximation (OA) method areinvestigated. No method shows the best performance in all cases, while in many situations,sum product algorithm, dwMDS, nonlinear least square, projection approach,OA, and weighted least square work well.
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| 6. |
- Gonzalez-Prelcic, Nuria, et al.
(författare)
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The Integrated Sensing and Communication Revolution for 6G: Vision, Techniques, and Applications
- 2024
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Ingår i: Proceedings of the IEEE. - 1558-2256 .- 0018-9219. ; In Press
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Tidskriftsartikel (refereegranskat)abstract
- Future wireless networks will integrate sensing, learning, and communication to provide new services beyond communication and to become more resilient. Sensors at the network infrastructure, sensors on the user equipment (UE), and the sensing capability of the communication signal itself provide a new source of data that connects the physical and radio frequency (RF) environments. A wireless network that harnesses all these sensing data can not only enable additional sensing services but also become more resilient to channel-dependent effects such as blockage and better support adaptation in dynamic environments as networks reconfigure. In this article, we provide a vision for integrated sensing and communication (ISAC) networks and an overview of how signal processing, optimization, and machine learning (ML) techniques can be leveraged to make them a reality in the context of 6G. We also include some examples of the performance of several of these strategies when evaluated using a simulation framework based on a combination of ray-tracing measurements and mathematical models that mix the digital and physical worlds.
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| 7. |
- Jiang, Fan, 1987-, et al.
(författare)
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Two-Timescale Transmission Design and RIS Optimization for Integrated Localization and Communications
- 2023
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Ingår i: IEEE Transactions on Wireless Communications. - Piscataway : IEEE. - 1536-1276 .- 1558-2248. ; 22:12, s. 8587-8602
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Tidskriftsartikel (refereegranskat)abstract
- Reconfigurable intelligent surfaces (RISs) have tremendous potential to boost communication performance, especially when the line-of-sight (LOS) path between the user equipment (UE) and base station (BS) is blocked. To control the RIS, channel state information (CSI) is needed, which entails significant pilot overhead. To reduce this overhead and the need for frequent RIS reconfiguration, we propose a novel framework for integrated localization and communications, where RIS configurations are fixed during location coherence intervals, while BS precoders are optimized every channel coherence interval. This framework leverages accurate location information obtained with the aid of several RISs as well as novel RIS optimization and channel estimation methods. Performance in terms of localization accuracy, channel estimation error, and achievable rate demonstrates the effectiveness of the proposed approach. © 2023 IEEE.
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| 8. |
- Jiang, Fan, 1987, et al.
(författare)
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Two-Timescale Transmission Design and RIS Optimization for Integrated Localization and Communications
- 2023
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Ingår i: IEEE Transactions on Wireless Communications. - 1558-2248 .- 1536-1276. ; 22:12, s. 8587-8602
-
Tidskriftsartikel (refereegranskat)abstract
- Reconfigurable intelligent surfaces (RISs) have tremendous potential to boost communication performance, especially when the line-of-sight (LOS) path between the user equipment (UE) and base station (BS) is blocked. To control the RIS, channel state information (CSI) is needed, which entails significant pilot overhead. To reduce this overhead and the need for frequent RIS reconfiguration, we propose a novel framework for integrated localization and communications, where RIS configurations are fixed during location coherence intervals, while BS precoders are optimized every channel coherence interval. This framework leverages accurate location information obtained with the aid of several RISs as well as novel RIS optimization and channel estimation methods. Performance in terms of localization accuracy, channel estimation error, and achievable rate demonstrates the effectiveness of the proposed approach.
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| 9. |
- Koirala, Remun, et al.
(författare)
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Direction Aided Multipath Channel Estimation for Millimeter Wave Systems
- 2021
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Ingår i: IEEE Vehicular Technology Conference. - 1550-2252. ; 2021-April
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Konferensbidrag (refereegranskat)abstract
- In this paper, we present a low-latency direction assisted channel estimation algorithm suitable for millimeter wave (mm-Wave) systems. First, during the beam training procedure, we perform angle of departure (AoD) and angle of arrival (AoA) measurements with their corresponding variances and based on them, we design both downlink and uplink beams. We then perform signal measurements with these beams and accordingly design the sensing matrix, while also iteratively refining the angle estimation and the beams for the next measurements accordingly. Finally, exploiting both the sparseness and the intrinsic geometric nature of the mm-Wave channel, we apply compressive sensing tools so as to complete the estimation procedure. Simulations show that the corresponding estimation error decreases rapidly in comparison with other conventional approaches.
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| 10. |
- Koirala, Remun, et al.
(författare)
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Localization and communication resource budgeting for multi-user mm-wave MIMO
- 2019
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Ingår i: 2019 16th Workshop on Positioning, Navigation and Communication, WPNC 2019.
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Konferensbidrag (refereegranskat)abstract
- In this paper, we study the trade-off between data and localization services while dividing time and frequency resources in a multi-user millimeter-wave system. In this multi-service system, budgeting more resources for the data service than for localization would indeed imply higher data rates but also, adversely, higher position and orientation estimation errors. Based on theoretical localization performance bounds and on the expression of the average data rate per user, we herein investigate and compare various ways the two different services could be operated.
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