| 1. |
- Fantini, R, et al.
(author)
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EU FP7 INFSO-ICT-317669 METIS, D3.2 First performance results for multi-node/multi-antenna transmission technologies
- 2014
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Reports (other academic/artistic)abstract
- This deliverable describes the current results of the multi-node/multi-antenna technologies investigated within METIS and analyses the interactions within and outside Work Package 3. Furthermore, it identifies the most promising technologies based on the current state of obtained results. This document provides a brief overview of the results in its first part. The second part, namely the Appendix, further details the results, describes the simulation alignment efforts conducted in the Work Package and the interaction of the Test Cases. The results described here show that the investigations conducted in Work Package 3 are maturing resulting in valuable innovative solutions for future 5G systems.
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| 2. |
- Carvalho, E. de, et al.
(author)
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EU FP7 INFSO-ICT-317669 METIS, D3.1 Positioning of multi-node/multi-antenna technologies
- 2013
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Reports (other academic/artistic)abstract
- This document describes the research activity in multi-node/multi-antenna technologies within METIS and positions it with respect to the state-of-the-art in the academic literature and in the standardization bodies. Based on the state-of-the-art and as well as on the METIS objectives,we set the research objectives and we group the different activities (or technology components) into research clusters with similar research objectives. The technologycomponents and the research objectives have been set to achieve an ambidextrous purpose. On one side we aim at providing the METIS system with those technological components that are a natural but non-trivial evolution of 4G. On the other side, we aim at seeking for disruptivetechnologies that could radically change 5G with respect to 4G. Moreover, we mapped the different technology components to METIS’ other activities and to the overall goals of theproject.
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| 3. |
- Apelfröjd, Rikke, 1986-
(author)
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Design Aspects of Coordinated Multipoint Transmission : A Study of Channel Predictions, Resource Allocation, User Grouping and Robust Linear Precoding for Coherent Joint Transmission
- 2014
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Licentiate thesis (other academic/artistic)abstract
- Shadowed areas and interference at cell borders pose great challenges for future wireless broadband systems. Coordinated Multipoint (CoMP) coherent joint transmission has shown the potential to overcome these challenges by turning harmful interference into useful signal power. However, there are obstacles to overcome before coherent joint transmission CoMP can be deployed. Some of these are the investigated in this thesis.First, coherent joint transmission requires very accurate Channel State Information (CSI), but unfortunately long system latencies cause outdating of the CSI. This can to some extend be counteracted by channel predictions. Two schemes are here investigated for predicting downlink Frequency Division Duplex (FDD) Orthogonal Frequency Division Multiplexing (OFDM) channels; Kalman filters and “predictor antennas”. The first is well suited for slow moving users, e.g. pedestrians or cyclists, as it does not require any special antenna setup. The second, which utilizes an extra antenna, located in front of the main receive antennas, is well suited for vehicular users, such as buses or trams, as these require long spatial prediction horizon.Second, a user grouping and resource allocation scheme is investigated. This scheme forms CoMP groups by local resource allocations and provides multi-user diversity gains very close to the optimal gains, found through an extensive combinatorial search. It has very low complexity, requires less feedback capacity than other schemes and places no demands on backhaul capacity.Finally, a linear precoder, which is robust to errors in the CSI, is investigated. This precoder takes the covariances of the channel errors into account while optimizing a Mean Squared Error (MSE) criterion. The MSE criterion includes design parameters that can be used as flexible tools for low dimensional searches with respect to an arbitrary optimization criterion, e.g. a weighted sum-rate criterion. The precoder design is also extended to handle backhaul constraints.Results show that with the combination of these three schemes: channel predictions, the proposed user grouping and resource allocation scheme and the robust linear precoder, then coherent joint transmission will indeed provide large capacity gains.
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| 4. |
- Phan-Huy, D.T., et al.
(author)
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5G on Board: How Many Antennas Do We Need on Connected Cars?
- 2016
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In: 2016 IEEE Globecom Workshops (GC Wkshps), 4-8 Dec. 2016. - New York : IEEE. - 2166-0069. - 9781509024827
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Conference paper (peer-reviewed)abstract
- Mobile networks will support increasing numbers of connected vehicles. Successive generations of mobile networks have reduced the cost of data rate, in terms of spectrum usage and power consumption at the base station, by increasingly exploiting the concept of channel state information at the transmitter. Unfortunately, beyond a limiting velocity (which depends on the carrier frequency), networks are no longer cost efficient, since such information is not usable. Recently, channel prediction techniques requiring several antennas on the car roof have been introduced to solve this problem. In this paper, for the first time, we determine the most cost efficient configurations, in terms of numbers of antennas on the car roof and carrier frequency, in various scenarios (highway and dense urban). Our studies show that with a simple prediction technique based on predictor antennas, the network can use twice less spectrum and around 20 dB less power, for cars with 3 antennas on their tops than for cars with the same number of antennas and not using prediction.
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| 5. |
- Phan-Huy, D.T., et al.
(author)
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Adaptive large MISO downlink with Predictor Antenna array for very fast moving vehicles
- 2013
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In: 2013 International Conference on Connected Vehicles and Expo, ICCVE 2013 - Proceedings. ; , s. 331-336
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Conference paper (peer-reviewed)abstract
- Recently, a 'Separate Receive and Training Antenna' technique has been proposed to provide energy efficient and robust wireless downlink data transmission towards antennas placed upon fast moving vehicles. Energy efficiency is attained thanks to Large Multiple Input Single Output Beamforming. Robustness to beamforming mispointing at high speed is obtained by using the recent 'Predictor Antenna' concept. However, for some speeds, the Separate Receive and Training Antenna technique suffers from residual mispointing. To improve the robustness of this technique, we propose three new schemes: the 'Border Switch Off Scheme', the 'Random Switch Off Scheme' and the 'Polynomial Interpolation' scheme. The two first schemes dynamically mute transmit antennas selectively when the residual mispointing is too severe. The third scheme generalizes the Predictor Antenna concept and uses all antennas upon the vehicle as a Predictor Antenna Array. These schemes are here assessed over spatially correlated channels. The two first schemes reduce energy saving to slightly improve robustness, whereas the third scheme perfectly compensates all speeds up to 300 kmph with maximum energy saving, at the cost of extra complexity. © 2013 IEEE.
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| 6. |
- Phan Huy, D-T, et al.
(author)
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Adaptive massive MIMO for fast moving connected vehicles : It will work with predictor antennas!
- 2018
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Conference paper (peer-reviewed)abstract
- Predicting the channel between a massive multiple input multiple output antenna and a car is a challenge, due to the short-term fading. It becomes essentially impossible by conventional extrapolation from past estimates if the car has moved by half a wavelength or more in space at the time when the channel estimate will be needed. This problem would prevent us from using the best fifth generation adaptive antenna downlink precoding schemes for very fast moving connected vehicles. A potential solution is to add another vehicle antenna, a "predictor antenna", which senses the channel in advance. In this paper, based on drive tests and channel measurements from a 64- element antenna to a car, we for the first time show that this concept works for massive MIMO downlinks. Thanks to the use of a predictor antenna, the complex OFDM downlink channels can be predicted with an accuracy that enables maximum ratio transmit beamforming with close to ideal beamforming gain for non-line-of-sight channels. Zero forcing transmission to two users results in a signal-to-interference ratio of 20 dB to 30 dB when predicting non-line-of-sight channels up to three wavelengths ahead in space. These first experiment shows that the predictor antenna concept is a potential solution to make fifth generation adaptive antennas work for very fast moving connected vehicles.
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