| 1. |
- Bourdoux, Andre, et al.
(författare)
-
D1.2 MaMi Channel Characteristics: Measurement Results
- 2015
-
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.
|
|
| 2. |
- Harrysson, Fredrik, et al.
(författare)
-
Efficient experimental evaluation of a MIMO handset with user influence
- 2010
-
Ingår i: IEEE Transactions on Wireless Communications. - 1536-1276. ; 9:2, s. 853-863
-
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.
|
|
| 3. |
- Harrysson, Fredrik, et al.
(författare)
-
Evaluation of an Outdoor-to-In-Car Radio Channel with a Four-Antenna Handset and a User Phantom
- 2011
-
Ingår i: Vehicular Technology Conference VTC 2011-Fall.
-
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.
|
|
| 4. |
- Harrysson, Fredrik, et al.
(författare)
-
Evaluation of user hand and body impact on multiple antenna handset
- 2010
-
Ingår i: [Host publication title missing]. - 1522-3965 .- 1947-1491. - 9781424449675
-
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.
|
|
| 5. |
- Harrysson, Fredrik, et al.
(författare)
-
Experimental Investigation of the Directional Outdoor-to-In-Car Propagation Channel
- 2013
-
Ingår i: IEEE Transactions on Vehicular Technology. - 1939-9359. ; 62:6, s. 2532-2543
-
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.
|
|
| 6. |
- Harrysson, Fredrik, et al.
(författare)
-
The composite channel method : Efficient experimental evaluation of a realistic MIMO terminal in the presence of a human body
- 2008
-
Ingår i: 2008 IEEE 67th Vehicular Technology Conference-Spring, VTC. - 1550-2252. - 9781424416455 ; , s. 473-477
-
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%.
|
|
| 7. |
|
|
| 8. |
- Bärring, Maja, 1988, et al.
(författare)
-
Factory Radio Design of a 5G Network in Offline Mode
- 2021
-
Ingår i: IEEE Access. - 2169-3536 .- 2169-3536. ; 9, s. 23095-23109
-
Tidskriftsartikel (refereegranskat)abstract
- The manufacturing industry is connecting people and equipment with new digital technologies, enabling a more continuous stream of data to represent processes. With more things connected, the interest in a connectivity solution that can support communication with high reliability and availability will increase. The fifth generation of telecommunication, i.e., 5G has promising features to deliver this, but the factory environment introduces new challenges to ensure reliable radio coverage. This will require efficient ways to plan the Factory Radio Design prior to installation. 3D laser scanning is used at an ever-increasing rate for capturing the spatial geometry in a virtual representation to perform layout planning of factories. This paper presents how to combine 3D laser scanning and physical optics (PO) for planning the Factory Radio Design of a cellular Long-Term Evolution (LTE) network (5G) in a virtual environment. 3D laser scanning is applied to obtain the spatial data of the factory and the virtual representation serves as the environment where PO computation techniques can be performed. The simulation result is validated in this paper by comparison to measurements of the installed network and empirical propagation models. The results of the study show promising opportunities to simulate the radio coverage in a virtual representation of a factory environment.
|
|
| 9. |
- Harrysson, Fredrik, et al.
(författare)
-
Dual antenna terminals in an indoor scenario
- 2006
-
Ingår i: [Host publication title missing]. - 1550-2252. ; 6, s. 2737-2741
-
Konferensbidrag (refereegranskat)abstract
- The performance of two different dual antenna hand-held test mobile terminals has been investigated in a realistic indoor office environment and scenario, with respect to antenna performance, diversity combining and Shannon MIMO channel capacity. Measurements of a 2times2 MIMO channel at 1877.5 MHz (narrowband) were performed using a dual-polarized base station antenna. Analyses show that diversity gains, using ideal selection combining and maximum ratio combining, between 0.7 and 4.6 dB was achieved at the 10% outage probability level. Ideal dual-side beamforming (single branch) gives up to 3.3 dB capacity gain compared to single antenna systems at SNR less than 10 dB, however, decreases with rising SNR. Dual branch MIMO capacity gain is only significant at higher SNR above 10 dB. In addition, horizontal polarization at the base station was found to outperform vertical polarization in this scenario
|
|
| 10. |
- Harrysson, Fredrik
(författare)
-
Modeling multiple antenna systems in realistic environments - a composite channel approach
- 2009
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- For evaluation of specific antenna arrangements in wireless communication systems we need physical channel models that take into account the directional domain. Here we propose a practical approach to wireless channel modeling in, particularly, mobile communication systems, by using an assumption that the channel can be divided into separate parts or regions that can be treated and modeled individually. The idea is that the antenna part of the channel is the part considered in the design of the user equipment and can be characterized by a single measurement of each design, while the propagation part of the channel can be characterized separately, independent of the user equipment, based on generic channel sounder measurements with, as far as possible, open areas around the transmitter and the receiver antennas. For more complex antenna environments we may imagine intermediate scattering regions of the channel model between the antenna parts and the propagation part, that perhaps can or cannot be handled separately, e.g., a mobile phone user body, an office desk, a vehicle etc. A first step in evaluating such a composite model approach is to verify the validity of link simulations were the mobile phone antennas together with the user can be handled as a super-antenna with its aggregate far-field pattern to be combined with a directional channel model in a classical way. This is presented in Paper IV and the method is in its extensible form referred to as the Composite Channel Method. It is found that this method, as we expected, work well for statistical performance evaluation of diversity or spatial multiplexing. An extension of the composite approach is outlined with an attempt to find a simple yet accurate directional scattering model for the user hand and body that still catch the proper influence of antenna efficiencies, fading statistics and correlation. Such an approach is tested and presented for a single antenna inside a car in Paper II. A full ray-tracing model as the one presented in Paper I and also used in Paper II can capture all important eects of a propagation environment also for multiple antennas systems to the price of high complexity of the geometrical model. In Paper III a first investigation of user influence on an indoor 2x2 MIMO link is performed based on a simple measurement setup and the diversity performance is evaluated. In Paper IV the first step of the composite channel approach is evaluated with respect to MIMO by channel measurements including user influence in static outdoor-to-indoor and indoor scenarios. The approach is verified for statistical properties such as antenna correlation and MIMO eigenvalue distributions. It is found that the presence of the user, apart from introducing hand and body absorption and mismatch that increases the path loss, also increases the correlation between the antenna elements and, thus, slightly decreases potential MIMO capacity.
|
|
| 11. |
- Harrysson, Fredrik
(författare)
-
Multiple Antenna Terminals in Realistic Environments - A Composite Channel Modeling Approach
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- For evaluation of specific antenna arrangements in wireless communication systems we need physical channel models that take into account also the directional domain of the propagation channel. In this thesis we investigate, validate and propose a practical approach to wireless channel modeling and, particularly, to mobile communication systems. For this we make the assumption that the channel can be divided into separate parts, or regions that can be treated and modeled separately. The basic idea is that the antenna parts of the channel is the parts considered in the design of base station antennas and user equipments and can be characterized by a single measurement of each design, while the propagation part of the channel can be characterized separately, independent of the specific installed base station antenna or the user equipment, but based on generic channel sounder measurements with, as far as possible, open areas around the transmitter and the receiver antennas. For more complex antenna environments we may imagine intermediate scattering regions of the channel model between the antenna parts and the propagation part, that can or cannot be handled separately, e.g., the body of a mobile phone user, an office desk, a vehicle, surroundings of base station antennas in dense deployments, etc. A first step in evaluating such a composite channel modeling approach is to verify the validity of communication link simulations were the mobile phone antennas together with the user can be treated as a super-antenna with its aggregate far-field pattern to be combined with a directional channel model in a classical way. This is first presented in Paper II, and the method is in its extensible form here referred to as a composite channel method. It is found that this method, as we expected, work well for statistical performance evaluation of diversity and spatial multiplexing. An extension of the composite approach is outlined with an attempt to find a simple yet accurate directional scattering model for, firstly, the user body, and, secondly, a car environment with the user inside. A simple model that still catch the proper influence of antenna efficiency, fading statistics, and correlation at the mobile side. In Paper I a first investigation of user influence on an indoor 2x2 multiple-input multiple-output (MIMO) link is performed based on a narrowband measurement setup and the diversity performance is evaluated. In Paper II, the first step of the composite channel approach is evaluated with respect to MIMO by channel measurements including user influence in two static outdoor-to-indoor and indoor-to-indoor scenarios. The approach is verified for statistical properties such as antenna correlation and MIMO eigenvalue distributions. It is found, with extended detail given in Paper III that the presence of the user, apart from introducing hand and body absorption and mismatch that increases the path loss, also increases the correlation between the antenna branch signals and, thus, slightly decreases potential MIMO capacity. In Paper IV and Paper V the investigation is extended to the scenario were the user is located inside a family car (station wagon). In Paper IV a first analysis of an outdoor MIMO measurements campaign with the user outside and inside the car is presented. The results show an increased scattering inside the car that improves mainly the potential diversity gain, and to some extent also the potential MIMO capacity gain, to the cost of higher path loss (lower SNR) due to car penetration loss. An important observation is the dependency of this penetration loss on the directional properties of the outer propagation channel, which indicates a possible need for scenario dependent penetration loss in general channel modeling. In Paper V this is further verified with directional estimation of the propagation channel both outside and inside the car. We also find that the composite channel method with the inherit assumption of plane-waves impinging on the mobile terminal, actually does produce good results even in this close near-field environment inside the car with the nearby scatterers within the far-field (Rayleigh) distance of the probe antenna array.
|
|
| 12. |
- Harrysson, Lars, et al.
(författare)
-
Cancer, a relational disease exploring the needs of relatives to cancer patients
- 2019
-
Ingår i: International Journal of Qualitative Studies on Health and Well-being. - : Informa UK Limited. - 1748-2631 .- 1748-2623. ; 14:1
-
Tidskriftsartikel (refereegranskat)abstract
- Syfte: I denna kvalitativa studie studerade vi erfarenheter bland familjemedlemmar till cancerpatienter. Vårt syfte var att undersöka och differentiera deras behov från de behov som cancer patienten uppvisar.Metod: Fem fokusintervjuer och sex individuella narrativa intervjuer med 17 familje medlemmar till cancerpatiener i Sverige genomfördes och jämförda med 19 intervjuer med cancerpatienter. Vår analys var inspirerad av klassisk grundad teori.Resaultat: Familjemedlemmar till cancerpatienter uppvisade egen sjukdom kopplad till höga stressnivåer och svårigheter att erkänna egen stress till följd av pågående jämförelser med cancerpatienten. Familjemedlemmar var fastlåsta i en momentan terrorlik situation där de blev den sjukes skyddsnät. En upplevd oförmåga till att förbättra den sjukes hälsa och välmående bidrog till känslor av skukld. Önskan om att allt skulle vara över var inbäddat i skam då slutet innebar möjlig död.Slutsatser: Genom att erkänna cancer som en sjukdom som påverkar både kropp och relationer kan familjemedlemmar ges kontroll över sina egna kamper skilda från patientens upplevelser. Vi definierar skillnaderi behov mellan cancer patienter och anhöriga. De anhöriga till cancerpatienter kan ges stöd i att utveckla balanserade strategier för mindre stress, ökad trygghet och stunder av förnöjsamhet.
|
|
| 13. |
- Karlsson, Kristian, et al.
(författare)
-
On the Keyhole Effect in Over-The-Air Testing of Higher Order MIMO Systems
- 2021
-
Ingår i: 15th European Conference on Antennas and Propagation, EuCAP 2021. - : Institute of Electrical and Electronics Engineers Inc.. - 9788831299022
-
Konferensbidrag (refereegranskat)abstract
- In this paper, the influence of a limited number of radio frequency connections between two Rayleigh fading environments, also known as the keyhole effect, is theoretically investigated for higher-order MIMO systems. It is shown that the effect of a limited number of keyholes is kept stable or is even reduced as the number of keyholes is equal to or larger than the MIMO system order. The results are relevant for over-the-air testing with connected Rayleigh fading systems, such as a channel emulator connected to a reverberation chamber, or a reverberation chamber connected to another reverberation chamber (nested reverberation chambers).
|
|
| 14. |
- Medbo, Jonas, et al.
(författare)
-
Temporal radio channel variations with stationary terminal
- 2004
-
Ingår i: [Host publication title missing]. - 1090-3038. - 0780385217 ; 1, s. 91-95
-
Konferensbidrag (refereegranskat)abstract
- In wireless communications, stationary terminal scenarios are becoming increasingly important as bitrates goes up. Consequently, the need to improve the knowledge about the channel behavior and to develop realistic channel models for these scenarios is also increasing. The present work comprises both measurements and modeling of the radio channel when the terminal is stationary. The measurements were performed at 5 GHz in indoor scenarios using a vector network analyzer. The measured channel was essentially static most of the time. Only about 1% of the time did it show substantial channel variations. An important finding is that the dominant cause for temporal channel variations in the measurements was the movement of persons in the vicinity of either antenna. This is also supported by a simple model, based on a single moving scatterer, which shows good agreement with measurements.
|
|
| 15. |
- Riback, Mathias, et al.
(författare)
-
Carrier frequency effects on path loss
- 2006
-
Ingår i: [Host publication title missing]. - 1550-2252. ; 6, s. 2717-2721
-
Konferensbidrag (refereegranskat)abstract
- To study the carrier frequency effects on path loss, measurements have been conducted at four discrete frequencies in the range 460-5100 MHz. The transmitter was placed on the roof of a 36 meters tall building and the receive antennas were placed on the roof of a van. Both urban and suburban areas were included in the measurement campaign. The results show that there is a frequency dependency, in addition to the well known free-space dependency 20 log10(f), in most of the areas included in the measurements. In non line of sight conditions, the excess path loss is clearly larger at the higher frequencies than at the lower. A model capturing these effects is presented
|
|
| 16. |
- Sandén, Ulrika, et al.
(författare)
-
A perspective-taking university course for cancer survivors, loved ones and healthcare professionals
- 2024
-
Ingår i: Social Sciences & Humanities Open. - : Elsevier. - 2590-2911. ; 2024:9
-
Tidskriftsartikel (refereegranskat)abstract
- This study reports the results of a university course aimed at exploring and improving cooperation in healthcare with both cancer survivors, loved ones and healthcare professionals as students.Central to the course was the understanding of and moving between each other's perspectives. Operating within a framework inspired by problem-based learning (PBL), small groups consisting of at least one cancer survivor, one loved one and one healthcare professional, collaboratively created scenarios based on their personal experiences. The students developed, elaborated, and identified problems and potential solutions. The pedagogical framing illustrated an empowering process of defining and elaborating a problem of their combined concerns, using their different knowledge. Although cooperation presented challenges, most students were able to explore and appreciate each other's perspectives when provided with a safe environment. Our experiences highlight the importance of both contextual safety and personal development as key factors in addressing power imbalances in healthcare.
|
|
| 17. |
- Sandén, Ulrika, et al.
(författare)
-
Breaking the patientification process - through co-creation of care, using old arctic survival knowledge
- 2021
-
Ingår i: International Journal of Qualitative Studies on Health and Well-being. - : Informa UK Limited. - 1748-2631 .- 1748-2623. ; 16:1
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: Cancer research and connected innovation processes often lack a major component; patient participation. We revisit three studies (a-c) in order to explore how Momentary contentment theory may be used to improve patient participation and psychosocial health.Method: We revisited data from the initial (a) classic grounded theory study on Momentary contentment, based on four years of observation and 14 interviews. It explains a way of dealing with life close to death and morbidity. In the imminence of danger the studied culture resembles the context of cancer patients. The two following studies used focus group interviews with (b) 19 cancer patients and (c) 17 relatives of cancer patients in southern Sweden.Results: We suggest a process where cancer patients are taught to be submissive and that the support they receive from health providers may be counterproductive to contentment; a patientification process. We present alternative ways for people to handle issues such as hope, waiting, knowledge gaps and healthcare navigation while living with cancer. We introduce an alternative to patientification and passive patients where active patients create their own safety and truly participates in their care. Conclusions: We propose clinical studies to introduce such a shift from patentification to co-creation of care.
|
|
| 18. |
- Sandén, Ulrika, et al.
(författare)
-
Exploring health navigating design : momentary contentment in a cancer context.
- 2017
-
Ingår i: International Journal of Qualitative Studies on Health and Well-being. - : Taylor & Francis. - 1748-2623 .- 1748-2631. ; 12:1, s. 1-12
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The technocratic and medicalized model of healthcare is rarely optimal for patients. By connecting two different studies we explore the possibilities of increasing quality of life in cancer care.METHODS: The first study captures survival strategies in a historically isolated Arctic village in Norway resulting in Momentary contentment theory, which emerged from analysing four years of participant observation and interview data. The second study conceptualizes everyday life of cancer patients based on in-depth interviews with 19 cancer patients; this was conceptualized as Navigating a new life situation. Both studies used classic grounded theory methodology. The connection between the studies is based on a health design approach.RESULTS: We found a fit between cancer patients challenging life conditions and harsh everyday life in an Arctic village. Death, treatments and dependence have become natural parts of life where the importance of creating spaces-of-moments and a Sense of Safety is imminent to well-being. While the cancer patients are in a new life situation, the Arctic people show a natural ability to handle uncertainties.CONCLUSION: By innovation theories connected to design thinking, Momentary contentment theory modified to fit cancer care would eventually be a way to improve cancer patients' quality of life.
|
|
| 19. |
|
|
