| 1. |
- Abdulla, Mouhamed, 1979, et al.
(författare)
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Fine-Grained vs. Average Reliability for V2V Communications around Intersections
- 2017
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Ingår i: IEEE Global Communications Conference (GLOBECOM'17). - 9781538639207 ; 2018-January, s. 1-5
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Konferensbidrag (refereegranskat)abstract
- Intersections are critical areas of the transportation infrastructure associated with 47% of all road accidents. Vehicle-to-vehicle (V2V) communication has the potential of preventing up to 35% of such serious road collisions. In fact, under the 5G/LTE Rel.15+ standardization, V2V is a critical use-case not only for the purpose of enhancing road safety, but also for enabling traffic efficiency in modern smart cities. Under this anticipated 5G definition, high reliability of 0.99999 is expected for semi-autonomous vehicles (i.e., driver-in-the-loop). As a consequence, there is a need to assess the reliability, especially for accident-prone areas, such as intersections. We unpack traditional average V2V reliability in order to quantify its related fine-grained V2V reliability. Contrary to existing work on infinitely large roads, when we consider finite road segments of significance to practical real-world deployment, fine-grained reliability exhibits bimodal behavior. Performance for a certain vehicular traffic scenario is either very reliable or extremely unreliable, but nowhere in relative proximity to the average performance.
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| 2. |
- Abdulla, Mouhamed, 1979, et al.
(författare)
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Vehicle-to-Vehicle Communications with Urban Intersection Path Loss Models
- 2016
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Ingår i: 2016 IEEE Globecom Workshops, GC Wkshps 2016 - Proceedings. ; , s. 1-6
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Konferensbidrag (refereegranskat)abstract
- Vehicle-to-vehicle (V2V) communication can improve road safety and traffic efficiency, particularly around critical areas such as intersections. We analytically derive V2V success probability near an urban intersection, based on empirically supported line-of-sight (LOS), weak-line-of-sight (WLOS), and nonline-of-sight (NLOS) channel models. The analysis can serve as a preliminary design tool for performance assessment over different system parameters and target performance requirements.
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| 3. |
- Abu-Shaban, Zohair, et al.
(författare)
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Distributed Two-Way Localization Bounds for 5G mmWave Systems
- 2018
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Ingår i: GLOBECOM - IEEE Global Telecommunications Conference.
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Konferensbidrag (refereegranskat)abstract
- Recently, localization for 5G millimeter-wave communication systems has been shown to provide high-accuracy performance, with error being in the order of tens of centimeters. However, most of the literature assumes a high level of synchronization, which is not always the case practically. To address this matter, we investigate a distributed two-way localization protocol (DLP) that relieves the need for tight timing synchronization. We derive the position and orientation bounds, when localization is initiated and carried out by the base station. Our simulation results show that the performance of DLP is identical to that of the synchronized one-way localization. We thus conclude that the considered 5G localization is limited by the estimation of the angles rather than the delay. The results also imply that orientation estimation is more challenging than position estimation.
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| 4. |
- Abu-Shaban, Z., et al.
(författare)
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Error Bounds for Uplink and Downlink 3D Localization in 5G Millimeter Wave Systems
- 2018
-
Ingår i: IEEE Transactions on Wireless Communications. - 1558-2248 .- 1536-1276. ; 17:8, s. 4939-4954
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Tidskriftsartikel (refereegranskat)abstract
- Location-aware communication systems are expected to play a pivotal part in the next generation of mobile communication networks. Therefore, there is a need to understand the localization limits in these networks, particularly, using millimeter-wave technology (mm-wave). Towards that, we address the uplink and downlink localization limits in terms of 3D position and orientation error bounds for mm-wave multipath channels. We also carry out a detailed analysis of the dependence of the bounds on different system parameters. Our key findings indicate that the uplink and downlink behave differently in two distinct ways. First of all, the error bounds have different scaling factors with respect to the number of antennas in the uplink and downlink. Secondly, uplink localization is sensitive to the orientation angle of the user equipment (UE), whereas downlink is not. Moreover, in the considered outdoor scenarios, the non-line-of-sight paths generally improve localization when a line-of-sight path exists. Finally, our numerical results show that mm-wave systems are capable of localizing a UE with sub-meter position error, and sub-degree orientation error.
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| 5. |
- Abu-Shaban, Z., et al.
(författare)
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Near-field Localization with a Reconfigurable Intelligent Surface Acting as Lens
- 2021
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Ingår i: IEEE International Conference on Communications. - 1550-3607. ; June 2021
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Konferensbidrag (refereegranskat)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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| 6. |
- Abu-Shaban, Z., et al.
(författare)
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Performance Analysis for Autonomous Vehicle 5g-Assisted Positioning in GNSS-Challenged Environments
- 2020
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Ingår i: 2020 IEEE/ION Position, Location and Navigation Symposium, PLANS 2020. ; , s. 996-1003
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Konferensbidrag (refereegranskat)abstract
- Standalone Global Navigation Satellite Systems (GNSS) are known to provide a positioning accuracy of a few meters in open sky conditions. This accuracy can drop significantly when the line-of-sight (LOS) paths to some GNSS satellites are obstructed, e.g., in urban canyons or underground tunnels. To overcome this issue, the general approach is usually to augment GNSS systems with other dedicated subsystems to help cover the gaps arising from obscured LOS. Positioning in 5G has attracted some attention lately, mainly due to the possibility to provide cm-level accuracy using 5G signals and infrastructure, effectively imposing no additional cost. In this paper, we study the hybridization of GNSS and 5G positioning in terms of achievable position and velocity error bounds. We focus on scenarios where satellite visibility is constrained by the environment geometry, and where the GNSS and 5G positioning systems fail to perform individually or provide prohibitively large error.
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| 7. |
- Abu-Shaban, Z., et al.
(författare)
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Performance of location and orientation estimation in 5G mmWave systems: Uplink vs downlink
- 2018
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Ingår i: IEEE Wireless Communications and Networking Conference, WCNC. - 1525-3511. ; 2018-April, s. 1-6
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Konferensbidrag (refereegranskat)abstract
- The fifth generation of mobile communications (5G) is expected to exploit the concept of location-aware communication systems. Therefore, there is a need to understand the localization limits in these networks, particularly, using millimeter-wave technology (mmWave). Contributing to this understanding, we consider single-anchor localization limits in terms of 3D position and orientation error bounds for mmWave multipath channels, for both the uplink and downlink. It is found that uplink localization is sensitive to the orientation angle of the user equipment (UE), whereas downlink is not. Moreover, in the considered outdoor scenarios, reflected and scattered paths generally improve localization. Finally, using detailed numerical simulations, we show that mmWave systems are in theory capable of localizing a UE with sub-meter position error, and sub-degree orientation error.
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| 8. |
- Abu-Shaban, Z., et al.
(författare)
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Random-phase beamforming for initial access in millimeter-wave cellular networks
- 2016
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Ingår i: Proceedings - IEEE Global Communications Conference, GLOBECOM. - 2334-0983 .- 2576-6813.
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Konferensbidrag (refereegranskat)abstract
- The utilization of the millimeter-wave frequency band (mm-wave) in the fifth generation ({5G}) of mobile communication is a highly-debated current topic. Mm-wave MIMO systems will use arrays with large number of antennas at the transmitter and the receiver, implemented on a relatively small area. With the inherent high directivity of these arrays, algorithms to help the user equipment find the base station and establish a communication link should be carefully designed. Towards that, we examine two beamforming schemes, namely, random-phase beamforming (RPBF) and directional beamforming (DBF), and test their impact on the Cram\'er-Rao lower bounds (CRB) of jointly estimating the direction-of-arrival, direction-of-departure, time-of-arrival, and the complex channel gain, under the line-of-sight channel model. The results show that the application of RPBF is more appropriate in the considered scenario as it attains a lower CRB with fewer beams compared to DBF.
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| 9. |
- Abu-Shaban, Z., et al.
(författare)
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Single-anchor two-way localization bounds for 5G mmWave systems
- 2020
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Ingår i: IEEE Transactions on Vehicular Technology. - 0018-9545 .- 1939-9359. ; 69:6, s. 6388-6400
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Tidskriftsartikel (refereegranskat)abstract
- Recently, millimeter-wave (mmWave) 5G localization has been shown to be to provide centimeter-level accuracy, lending itself to many location-aware applications, e.g., connected autonomous vehicles (CAVs). One assumption usually made in the investigation of localization methods is that the user equipment (UE), i.e., a CAV, and the base station (BS) are time synchronized. In this paper, we remove this assumption and investigate two two-way localization protocols: (i) a round-trip localization protocol (RLP), whereby the BS and UE exchange signals in two rounds of transmission and then localization is achieved using the signal received in the second round; (ii) a collaborative localization protocol (CLP), whereby localization is achieved using the signals received in the two rounds. We derive the position and orientation error bounds applying beamforming at both ends and compare them to the traditional one-way localization. Our results show that mmWave localization is mainly limited by the angular rather than the temporal estimation and that CLP significantly outperforms RLP. Our simulations also show that it is more beneficial to have more antennas at the BS than at the UE.
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| 10. |
- Ahmad, Suhail, 1992, et al.
(författare)
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Predictive Resource Allocation Evaluation with Real Channel Measurements
- 2017
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Ingår i: IEEE International Conference on Communications. - 1550-3607.
-
Konferensbidrag (refereegranskat)abstract
- Mobile services, especially video streaming, has seen a rapid usage increase in recent years. Base stations (BSs) need to employ smarter and efficient resource allocation strategies to maintain high quality of service (QoS) to users at all the times. Predictive resource allocation (PRA), is one such novel scheme, in which BSs seek to anticipate the user demands and offer service to users in advance. As a result, the QoS can be improved, network load can be distributed over time, while at the same time offering efficient utilization of BS power. In location-aware PRA, the BS exploits location information of the users to predict the channel expected variations and adapt the BS resources accordingly. We evaluate PRA strategies based on an empirical study of the radio channel variation from measured location-aided channel radio maps using a smart phone. We observed that gains offered by the PRA scheme are highly dependent on user mobility patterns.
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