| 1. |
- Harrysson, Fredrik, et al.
(författare)
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Evaluation of an Outdoor-to-In-Car Radio Channel with a Four-Antenna Handset and a User Phantom
- 2011
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Ingår i: Vehicular Technology Conference VTC 2011-Fall.
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Konferensbidrag (refereegranskat)abstract
- Based on static outdoor channel measurements we evaluate the influence of a vehicle on the MIMO radio channel, from a base station antenna array, to a multiple antenna handset in the hand of a user placed inside a test car. The measurement scenario is chosen to mimic a 2.6 GHz (LTE) macro-cell urban or rural scenario with two locations and orientations of the car, one at an open parking lot with a strong line-of-sight component, and one between buildings with no line-of-sight. The measurements are repeated several times with the user phantom plus handset positioned at the same spot within the car and with the car absent. Figures of the penetration loss, impact on fading statistics, mean delay, delay spread, terminal antenna correlation, eigenvalue distributions, as well as the performance of various hybrid diversity combining and spatial multiplexing schemes, are evaluated and compared with and without the vehicle present. It is found that the car make the channel statistics become more Rayleigh like and increases multipath channel richness, improving the potential of diversity gain and, to some extent, spatial multiplexing.
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| 2. |
- Harrysson, Fredrik, et al.
(författare)
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Experimental Investigation of the Directional Outdoor-to-In-Car Propagation Channel
- 2013
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Ingår i: IEEE Transactions on Vehicular Technology. - 1939-9359. ; 62:6, s. 2532-2543
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Abstract in UndeterminedThe demand for wireless channel models including realistic user environments is increasing. This motivates work on more detailed models that are reasonably simple and tractable but with adequatestatistical performance. In this paper, we present an investigation of the spatial outdoor-to-in-car radio channel at 2.6 GHz. Specifically, we investigate the performance of a multiple antenna smartphone mockup in the hand of a user. We evaluate and utilize a composite channel approach to combine measured antenna radiation patterns with an estimated spectral representation of the multipath channel outside and inside the car in two different scenarios. The performance of the method is investigated and comparisons with direct channel measurements are performed. Statistical and directional properties of the outdoorto-in-car channel are presented and analyzed. It is found that the composite method, despite nearfieldproblems when estimating plane-wave channel parameters in a very narrow environment, constitutes a tool that provides reasonably viable statistical results. In addition, we have found that the introduction of the car in the propagation environment increases scattering and eigenvalue dispersion while it decreases pairwise antenna signal correlation. These statistical properties are found to slightly increase the possible diversity and the spatial multiplexing gains of multiple antenna terminals when located inside cars. Thispositive effect, however, is small compared to the negative effect of car penetration loss.
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| 3. |
- Hult, Tommy, et al.
(författare)
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Analytical dual-link MIMO channel model using correlated correlation matrices
- 2010
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Ingår i: Proceedings of the Fourth European Conference on Antennas and Propagation. - 9788476534724 - 9781424464319
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Konferensbidrag (refereegranskat)abstract
- Analytical Multiple-Input Multiple-Output (MIMO) models are often attractive due to their low complexity when analyzing possibilities and limitations in the system. In this paper we outline a a possible dual link extension of an analytical MIMO channel model and investigate its suitability based on measurements of a dual link MIMO scenario. The extension is based on the correlation matrix distance (CMD) as a gauge to generate correlation matrices for the additional links of the multi-link scenario.
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| 4. |
- Kolmonen, Veli-Matti, et al.
(författare)
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Measurement-based evaluation of interlink correlation for indoor multi-user MIMO Channels
- 2010
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1548-5757. ; 9, s. 311-314
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in UndeterminedThe properties of the single-link multiple-input-multiple- output (MIMO) propagation channels have been analyzed in many studies based on extensive propagation measurements. In this letter, we extend the measurement-based analysis to dual-link MIMO propagation channels. Here, we examine interlink correlation by evaluating the correlation of eigenvectors obtained from multiple MIMO links. We also investigated how the physical propagation phenomena produced the interlink correlation. Results indicate that interlink correlation may exist. Sometimes it is found to be very high also for far separated receive units, depending on similarity of dominant propagation mechanisms between multiple MIMO links and also on antenna array properties.
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| 5. |
- Poutanen, Juho, et al.
(författare)
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Significance of common scatterers in multi-link indoor radio wave propagation
- 2010
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Ingår i: Proceedings of the Fourth European Conference on Antennas and Propagation. - 9788476534724 - 9781424464319
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Konferensbidrag (refereegranskat)abstract
- Correlation between different links is an essential characteristic for many of the forthcoming radio communication systems that utilize the multiple-input-multiple-output (MIMO) technology. This paper investigates the physical phenomena that cause the inter-link correlation by introducing a measure to quantify how large amount of energy propagates via similar propagation mechanisms in different links. The conditions for the so-called significance of common scatterers are derived and two dynamic dual-link indoor MIMO channel measurements are used to provide experimental results. The present work forms the indispensable basis for the channel modeling of multiuser MIMO communications.
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| 6. |
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