The Experts below are selected from a list of 108 Experts worldwide ranked by ideXlab platform
Xuefeng Yin - One of the best experts on this subject based on the ideXlab platform.
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experimental characterization and multipath cluster modeling for 13 17 ghz indoor propagation channels
IEEE Transactions on Antennas and Propagation, 2017Co-Authors: Cen Ling, Xuefeng Yin, Haowen Wang, Reiner S ThomaAbstract:The traffic explosion of mobile communications increasingly requires effective and realistic fifth-generation (5G) channel models. Recently, we have Conducted Measurement campaigns in lecture hall and laboratory scenarios using steerable beam antennas for characterizing 13–17 GHz channels. The Space-Alternating Generalized Expectation–maximization (SAGE) algorithm was applied to estimate the multipath components (MPCs) in delay and angle of arrival domains. These estimated MPCs were further grouped into clusters via the threshold-based approach. It is noticeable that the observed channel characteristics obtained using the SAGE algorithm are less antenna-specific than those using the raw received signals. The scatterer locations identified from the MPCs show excellent agreement with the physical objects in the environment. Moreover, we found that the configurations of antenna-half-power-beamwidth and rotation step size exert great influence on the channel characteristics. These results provide important references for the existing 5G channel sounding and data processing, which naturally leads to fidelity of future channel models.
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a geometry based path loss model for high speed train environments in lte a networks
2016 International Conference on Computing Networking and Communications (ICNC), 2016Co-Authors: Xuesong Cai, Xuefeng Yin, Yu Shen, Xiang ChengAbstract:In this paper, a recently Conducted Measurement campaign for High-Speed-Train (HST) channels is introduced where the down-link signals of in-service Long Time Evolution-Advanced (LTE-A) networks deployed along a HST railway between Beijing to Shanghai were acquired. The channel impulse responses (CIRs) are extracted from the received Cell-specific Reference Signals (CRSs). The results show that, most of the channels contain a delay trajectory corresponding to a line-of-sight (LoS) path. The geometry parameters such as the train speed and the minimal distance between the transmitter and the receiver are extracted from the delay trajectories. Furthermore, path loss characteristics along the trajectories are investigated and compared with the model extracted for the Universal Mobile Telecommunications System (UMTS).
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empirical geometry based random cluster model for high speed train channels in umts networks
IEEE Transactions on Intelligent Transportation Systems, 2015Co-Authors: Xuefeng Yin, Xuesong Cai, Xiang Cheng, Jiajing Chen, Meng TianAbstract:In this paper, a recently Conducted Measurement campaign for high-speed-train (HST) channels is introduced, where the downlink signals of an in-service Universal Mobile Terrestrial System (UMTS) deployed along an HST railway between Beijing and Shanghai were acquired. The channel impulse responses (CIRs) are extracted from the data received in the common pilot channels (CPICHs). Within 1318 km, 144 base stations (BSs) were detected. Multipath components (MPCs) estimated from the CIRs are clustered and associated across the time slots. The results show that, limited by the sounding bandwidth of 3.84 MHz, most of the channels contain a single line-of-sight (LoS) cluster, and the rest consists of several LoS clusters due to distributed antennas, leaking cable, or neighboring BSs sharing the same CPICH. A new geometry-based random-cluster model is established for the clusters' behavior in delay and Doppler domains. Different from conventional models, the time-evolving behaviors of clusters are characterized by random geometrical parameters, i.e., the relative position of BS to railway, and the train speed. The distributions of these parameters, and the per-cluster path loss, shadowing, delay, and Doppler spreads, are extracted from the Measurement data.
John F Schnelle - One of the best experts on this subject based on the ideXlab platform.
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the minimum data set weight loss quality indicator does it reflect differences in care processes related to weight loss
Journal of the American Geriatrics Society, 2003Co-Authors: Sandra F Simmons, Emily Garcia, Mary P Cadogan, Nahla R Alsamarrai, Lene Levystorms, Dan Osterweil, John F SchnelleAbstract:OBJECTIVES: To determine whether nursing homes (NHs) that score differently on prevalence of weight loss, according to a Minimum Data Set (MDS) quality indicator, also provide different processes of care related to weight loss. DESIGN: Cross-sectional. SETTING: Sixteen skilled nursing facilities: 11 NHs in the lower (25th percentile-low prevalence) quartile and five NHs in the upper (75th percentile-high prevalence) quartile on the MDS weight-loss quality indicator. PARTICIPANTS: Four hundred long-term residents. MeasurementS: Sixteen care processes related to weight loss were defined and operationalized into clinical indicators. Trained research staff Conducted Measurement of NH staff implementation of each care process during assessments on three consecutive 12-hour days (7 a.m. to 7 p.m.), which included direct observations during meals, resident interviews, and medical record abstraction using standardized protocols. RESULTS: The prevalence of weight loss was significantly higher in the participants in the upper quartile NHs than in participants in the lower quartile NHs based on MDS and monthly weight data documented in the medical record. NHs with a higher prevalence of weight loss had a significantly larger proportion of residents with risk factors for weight loss, namely low oral food and fluid intake. There were few significant differences on care process measures between low- and high-weight-loss NHs. Staff in low-weight-loss NHs consistently provided verbal prompting and social interaction during meals to a greater proportion of residents, including those most at risk for weight loss. CONCLUSION: The MDS weight-loss quality indicator reflects differences in the prevalence of weight loss between NHs. NHs with a lower prevalence of weight loss have fewer residents at risk for weight loss and staff who provide verbal prompting and social interaction to more residents during meals, but the adequacy and quality of feeding assistance care needs improvement in all NHs.
Thomas J. Afullo - One of the best experts on this subject based on the ideXlab platform.
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Measurements and Analysis of Large-Scale Path Loss Model at 14 and 22 GHz in Indoor Corridor
IEEE Access, 2018Co-Authors: Nicholas O. Oyie, Thomas J. AfulloAbstract:Fifth generation wireless communications will exploit the enormous chunk of bandwidth available at millimeter-wave frequency bands. Accordingly, an accurate and simple path loss model is critical for indoor environments, where deployment is likely to occur. We Conducted Measurement campaigns in the 14 and 22 GHz frequency bands in a typical indoor corridor environment on 5th floor of the Discipline of Electrical, Electronic and Computer Engineering building, University of KwaZulu-Natal, Howard Campus, South Africa. This paper presents details of Measurement campaigns with unique transmitter-receiver combinations using a costume-designed channel sounder. The acquired Measurement results provide large-scale path loss statistics in an open-plan indoor environment in line-of-sight and non-line-of-sight conditions. An effective application of dual slope single-frequency directional large-scale path loss model is evaluated based on the acquired Measurement data. The application of dual slope large-scale path loss model is supported by a comprehensive analysis and consideration of propagation mechanisms, such as reflection and diffraction resulting in modal attenuation. Validated results show that dual slope large-scale path loss model applied in this paper outperforms close-in reference distance model that assumes the impact of propagating wave guiding effect in indoor corridors.
Gert Frølund Pedersen - One of the best experts on this subject based on the ideXlab platform.
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Experimental Characterization of Millimeter-Wave Indoor Propagation Channels at 28 GHz
IEEE Access, 2018Co-Authors: Guojin Zhang, Panawit Hanpinitsak, Jun-ichi Takada, Kentaro Saito, Gert Frølund PedersenAbstract:The increasing requirement for the mobile data traffic accelerates the research of millimeter-wave (mm-wave) for future wireless systems. Accurate characterization of the mm-wave propagation channel is fundamental and essential for the system design and performance evaluation. In this paper, we Conducted Measurement campaigns in various indoor scenarios, including classroom, office, and hall scenarios, at the frequency bands of 27–29 GHz. The spatial channel characteristics were recorded by using a large-scale uniform circular array. A high-resolution parameter estimation algorithm was applied to estimate the mm-wave spherical propagation parameters, i.e., the azimuth angle, elevation angle, delay, source distance, and complex amplitude of multipath components. With the same Measurement system, the channel parameters including decay factor, delay spread, angular spread, and line of sight power ratio are investigated thoroughly in individual indoor scenarios and compared in different indoor scenarios. Furthermore, the impact of the furniture richness level and indoor geometry on the propagation parameters are also investigated.
Xiang Cheng - One of the best experts on this subject based on the ideXlab platform.
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a geometry based path loss model for high speed train environments in lte a networks
2016 International Conference on Computing Networking and Communications (ICNC), 2016Co-Authors: Xuesong Cai, Xuefeng Yin, Yu Shen, Xiang ChengAbstract:In this paper, a recently Conducted Measurement campaign for High-Speed-Train (HST) channels is introduced where the down-link signals of in-service Long Time Evolution-Advanced (LTE-A) networks deployed along a HST railway between Beijing to Shanghai were acquired. The channel impulse responses (CIRs) are extracted from the received Cell-specific Reference Signals (CRSs). The results show that, most of the channels contain a delay trajectory corresponding to a line-of-sight (LoS) path. The geometry parameters such as the train speed and the minimal distance between the transmitter and the receiver are extracted from the delay trajectories. Furthermore, path loss characteristics along the trajectories are investigated and compared with the model extracted for the Universal Mobile Telecommunications System (UMTS).
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empirical geometry based random cluster model for high speed train channels in umts networks
IEEE Transactions on Intelligent Transportation Systems, 2015Co-Authors: Xuefeng Yin, Xuesong Cai, Xiang Cheng, Jiajing Chen, Meng TianAbstract:In this paper, a recently Conducted Measurement campaign for high-speed-train (HST) channels is introduced, where the downlink signals of an in-service Universal Mobile Terrestrial System (UMTS) deployed along an HST railway between Beijing and Shanghai were acquired. The channel impulse responses (CIRs) are extracted from the data received in the common pilot channels (CPICHs). Within 1318 km, 144 base stations (BSs) were detected. Multipath components (MPCs) estimated from the CIRs are clustered and associated across the time slots. The results show that, limited by the sounding bandwidth of 3.84 MHz, most of the channels contain a single line-of-sight (LoS) cluster, and the rest consists of several LoS clusters due to distributed antennas, leaking cable, or neighboring BSs sharing the same CPICH. A new geometry-based random-cluster model is established for the clusters' behavior in delay and Doppler domains. Different from conventional models, the time-evolving behaviors of clusters are characterized by random geometrical parameters, i.e., the relative position of BS to railway, and the train speed. The distributions of these parameters, and the per-cluster path loss, shadowing, delay, and Doppler spreads, are extracted from the Measurement data.