| 1. |
- Abu-Shaban, Z., et al.
(author)
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Near-field Localization with a Reconfigurable Intelligent Surface Acting as Lens
- 2021
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In: IEEE International Conference on Communications. - 1550-3607. ; June 2021
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Conference paper (peer-reviewed)abstract
- Exploiting wavefront curvature enables localization with limited infrastructure and hardware complexity. With the introduction of reconfigurable intelligent surfaces (RISs), new opportunities arise, in particular when the RIS is functioning as a lens receiver. We investigate the localization of a transmitter using a RIS-based lens in close proximity to a single receive antenna element attached to reception radio frequency chain. We perform a Fisher information analysis, evaluate the impact of different lens configurations, and propose a two-stage localization algorithm. Our results indicate that positional beamforming can lead to better performance when a priori location information is available, while random beamforming is preferred when a priori information is lacking. Our simulation results for a moderate size lens operating at 28 GHz showcased that decimeter-level accuracy can be attained within 3 meters to the lens.
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| 2. |
- Aydogdu, Canan, 1978, et al.
(author)
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Automotive Radar Interference Mitigation via Multi-Hop Cooperative Radar Communications
- 2021
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In: EuRAD 2020 - 2020 17th European Radar Conference. ; , s. 270-273
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Conference paper (peer-reviewed)abstract
- We investigate the interference mitigation performance of cooperative radar communications in dynamic multi-hop vehicular ad-hoc networks, where each automotive radar is not in the field of view of others. This study builds on top of our former proposed cooperative radar communications solution, RadChat, which uses a single hardware for both radar and communication purposes. Simulation results obtained for high-way traffic scenarios show that RadChat functions with quite a low latency while decreasing the interference significantly.
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| 3. |
- Aydogdu, Canan, 1978, et al.
(author)
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Radar Interference Mitigation for Automated Driving : Exploring Proactive Strategies
- 2020
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In: IEEE signal processing magazine (Print). - Piscataway : Institute of Electrical and Electronics Engineers (IEEE). - 1053-5888 .- 1558-0792. ; 37:4, s. 72-84
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Journal article (peer-reviewed)abstract
- Autonomous driving relies on a variety of sensors, especially radars, which have unique robustness under heavy rain/fog/snow and poor light conditions. With the rapid increase of the amount of radars used on modern vehicles, where most radars operate in the same frequency band, the risk of radar interference becomes a compelling issue. This article analyzes automotive radar interference and proposes several new approaches that combine industrial and academic expertise toward the goal of achieving interference-free autonomous driving (AD). © IEEE.
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| 4. |
- Aydogdu, Canan, 1978, et al.
(author)
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Radar Interference Mitigation through Active Coordination
- 2021
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In: IEEE National Radar Conference - Proceedings. - : IEEE. - 1097-5659. ; 2021-May, s. 1-6
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Conference paper (peer-reviewed)abstract
- Intelligent transportation is heavily reliant on radar, which have unique robustness under heavy rain/fog/snow and poor light conditions. With the rapid increase of the number of radars used on modern vehicles, most operating in the same frequency band, the risk of radar interference becomes an important issue. As in radio communication, interference can be mitigated through coordination. We present and evaluate two approaches for radar interference coordination, one for FMCW and one for OFDM, and highlight their challenges and opportunities.
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| 5. |
- Aydogdu, Canan, 1978, et al.
(author)
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RadChat: Spectrum Sharing for Automotive Radar Interference Mitigation
- 2021
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In: IEEE Transactions on Intelligent Transportation Systems. - 1524-9050 .- 1558-0016. ; 22:1, s. 416-429
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Journal article (peer-reviewed)abstract
- In the automotive sector, both radars and wireless communication are susceptible to interference. However, combining the radar and communication systems, i.e., radio frequency (RF) communications and sensing convergence, has the potential to mitigate interference in both systems. This article analyses the mutual interference of spectrally coexistent frequency modulated continuous wave (FMCW) radar and communication systems in terms of occurrence probability and impact, and introduces RadChat, a distributed networking protocol for mitigation of interference among FMCW based automotive radars, including self-interference, using radar and communication cooperation. The results show that RadChat can significantly reduce radar mutual interference in single-hop vehicular networks in less than 80 ms.
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| 6. |
- Baquero Barneto, Carlos, et al.
(author)
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Millimeter-wave Mobile Sensing and Environment Mapping: Models, Algorithms and Validation
- 2022
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In: IEEE Transactions on Vehicular Technology. - 0018-9545 .- 1939-9359. ; 71:4, s. 3900-3916
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Journal article (peer-reviewed)abstract
- Integrating efficient connectivity, positioning and sensing functionalities into 5G New Radio (NR) and beyond mobile cellular systems is one timely research paradigm, especially at mm-wave and sub-THz bands. In this article, we address the radio-based sensing and environment mapping prospect with specific emphasis on the user equipment (UE) side. We first describe an efficient $\ell_1$-regularized least-squares (LS) approach to obtain sparse range--angle charts at individual measurement or sensing locations. For the subsequent environment mapping, we then introduce a novel state model for mapping diffuse and specular scattering, which allows efficient tracking of individual scatterers over time using interacting multiple model (IMM) extended Kalman filter and smoother. Also the related measurement selection and data association problems are addressed. We provide extensive numerical indoor mapping results at the 28~GHz band deploying OFDM-based 5G NR uplink waveform with 400~MHz channel bandwidth, covering both accurate ray-tracing based as well as actual RF measurement results. The results illustrate the superiority of the dynamic tracking-based solutions, compared to static reference methods, while overall demonstrate the excellent prospects of radio-based mobile environment sensing and mapping in future mm-wave networks.
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| 7. |
- Bartoletti, Stefania, et al.
(author)
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Positioning and Sensing for Vehicular Safety Applications in 5G and Beyond
- 2021
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In: IEEE Communications Magazine. - 0163-6804 .- 1558-1896. ; 59:11, s. 15-21
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Journal article (peer-reviewed)abstract
- This article presents a shared vision among stakeholders across the value chain on the use of radio positioning and sensing for road safety in the 5G ecosystem. The key enabling technologies and architectural functionalities are explored, focusing on the extremely stringent localization and communication requirements. A case study for joint radar and communication using experimental data showcases the potential of the new enablers that are paving the way toward enhanced road safety in beyond 5G scenarios.
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| 8. |
- Behravan, Ali, 1971, et al.
(author)
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Positioning and Sensing in 6G: Gaps, Challenges, and Opportunities
- 2023
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In: IEEE Vehicular Technology Magazine. - 1556-6080 .- 1556-6072. ; 18:1, s. 40-48
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Journal article (peer-reviewed)abstract
- Among the key differentiators of 6G compared to 5G will be the increased emphasis on radio-based positioning and sensing. These will be utilized not only for conventional location-aware services and for enhancing communication performance but also to support new use case families with extreme performance requirements. This article presents a unified vision from stakeholders across the value chain in terms of both opportunities and challenges for 6G positioning and sensing as well as use cases, performance requirements, and gap analysis. Combined, this motivates the technical advances in 6G and guides system design.
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| 9. |
- Carvajal, Gisela, 1983, et al.
(author)
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Comparison of Automotive FMCW and OFDM Radar Under Interference
- 2020
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In: IEEE National Radar Conference - Proceedings. - New York, NY : IEEE. - 1097-5659. ; 2020-September
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Conference paper (peer-reviewed)abstract
- Automotive radars are subject to interference in spectrally congested environments. To mitigate this interference, various waveforms have been proposed. We compare two waveforms (FMCW and OFDM) in terms of their radar performance and robustness to interference, under similar parameter settings. Our results indicate that under proper windowing both waveforms can achieve similar performance, but OFDM is more sensitive to interference.
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| 10. |
- Chen, Hui, 1992, et al.
(author)
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6G Localization and Sensing in the Near Field: Features, Opportunities, and Challenges
- 2024
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In: IEEE Wireless Communications. - 1536-1284 .- 1558-0687. ; In press
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Journal article (peer-reviewed)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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