| 1. |
- Bourdoux, Andre, et al.
(författare)
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D1.2 MaMi Channel Characteristics: Measurement Results
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This deliverable presents channel measurement results for the scenariosOpen exhibition and Crowded auditiorium. The measurement procedureand equipment are described. Massive MIMO (MaMi) channel characteristicsand key parameters are extracted and used in an extended COST 2100channel model for MaMi. The initial validation performed shows that themodel is capable of reproducing the statistics in terms of temporal behaviorof the user separability, singular value spread, capacity and sum-rate anddirectional characteristics. The model can be used for system and link levelMaMi simulations.
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| 2. |
- Harrysson, Fredrik, et al.
(författare)
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Efficient experimental evaluation of a MIMO handset with user influence
- 2010
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Ingår i: IEEE Transactions on Wireless Communications. - 1536-1276. ; 9:2, s. 853-863
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Tidskriftsartikel (refereegranskat)abstract
- The immediate environment of handset antennas, including the casings and the users holding the handsets, has a strong impact on the radio channel in mobile communication. In this paper we investigate a composite channel method that synthetically combines double-directional measurements of the userless propagation channel with measured super-antenna patterns, i.e., patterns of the combined antenna-casing-user arrangement. We experimentally evaluate the method by comparing results (power, capacity, and eigenvalue distribution) obtained from this composite method with direct measurements in the same environment. The measurements were done in two static 8 × 4 MIMO scenarios at 2.6 GHz, with the user indoors and the base station located outdoors and indoors, respectively. A realistic user phantom together with a “smart-phone” handset mock-up with four antenna elements was used, and different configurations and orientations were tested. The method gives statistical distributions of the MIMO eigenvalues, that are close to the measured. By using the composite method, we found that the user, apart from introducing hand and body loss that mainly decreases the SNR of the channel, slightly increases the correlation between the fading at the antenna elements.
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| 3. |
- 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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| 4. |
- Harrysson, Fredrik, et al.
(författare)
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Evaluation of user hand and body impact on multiple antenna handset
- 2010
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Ingår i: [Host publication title missing]. - 1522-3965 .- 1947-1491. - 9781424449675
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Konferensbidrag (refereegranskat)abstract
- From our experimental investigation of multiple-antenna performance and user impact of a realistic mobile terminal setup, we find that apart from the important loss of efficiency due to the user hand, the impact on the individual antennna elements and the directional impact of the user body shadowing have quite small influence on the diversity and capacity performance. It is found that the top and bottom placement of antennas within the handset case are the most efficient to be used with up to two antenna elements. There are, however, significant diversity and capacity gain that can be explored by using four distributed antennas even if only two radio chains are available through hybrid selection and combining schemes. It was also found that the practical method of choosing antennas based on signal power for 2 branch MIMO with 4 available handset antennas, performs well compared to the optimal solution.
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| 5. |
- 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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| 6. |
- Harrysson, Fredrik, et al.
(författare)
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The composite channel method : Efficient experimental evaluation of a realistic MIMO terminal in the presence of a human body
- 2008
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Ingår i: 2008 IEEE 67th Vehicular Technology Conference-Spring, VTC. - 1550-2252. - 9781424416455 ; , s. 473-477
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Konferensbidrag (refereegranskat)abstract
- The immediate environment of the transmit (TX) and receive (RX) antennas, including the antenna casings and the users holding the antennas, has a strong impact on the propagation channel and thus on wireless systems. In this paper we experimentally evaluate a method that synthetically combines double-directional measurements of the propagation channel (without the user influence) with measured antenna patterns of antennas-plus-users, by comparing obtained sample results with direct measurements in the same environment. The measurements are done for a static microcell 8×4 MIMO scenario at 2.6 GHz. A realistic user phantom was used together with a test terminal prototype with four antenna elements, and a number of different configurations and orientations of the phantom were tested. In average over all test cases, the mean signal power deviation between composite channel method and measurements was well within 1 dB. The composite method shows 6% higher terminal antenna correlation but similar statistical distributions as the measured. The differences between the model and measurements for the strongest eigenvalue (relevant for MRC combining) was found to be within 1 dB above 10% outage level. Relative deviations in the ergodic MIMO capacity were smaller than 10%.
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| 7. |
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