The Experts below are selected from a list of 5922 Experts worldwide ranked by ideXlab platform
Wilhelm Keusgen - One of the best experts on this subject based on the ideXlab platform.
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statistical evaluation of Multipath Component lifetime in the car to car channel at urban street intersections based on geometrical tracking
Vehicular Technology Conference, 2012Co-Authors: Panagiotis Paschalidis, Kim Mahler, Andreas Kortke, Michael Peter, Wilhelm KeusgenAbstract:In this paper we present a statistical evaluation of the lifetime of Multipath Components for the vehicular radio channel. We introduce a new identification and tracking algorithm. The algorithm follows a geometrical approach exploiting the high scatterer resolution in the measurement data and takes as an estimation basis considerations on the relative movement of the scatterer. We subsequently apply the algorithm to evaluate the measured data. We use wideband channel measurement data collected at urban street intersections under NLOS-conditions. We sequentially evaluate weighted interrelations between detected contributions in the time-delay domain and decide on common underlying scatterers or not. We suggest a classification of distinct and diffuse contributions by means of a threshold with respect to lifetime and discuss on their temporal characteristics, based on an exemplary measurement with typical values. In specific we characterize the lifetime by means of a probability density function and further examine the relation of lifetime and power level of the Multipath contribution.
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VTC Spring - Statistical Evaluation of Multipath Component Lifetime in the Car-to-Car Channel at Urban Street Intersections Based on Geometrical Tracking
2012 IEEE 75th Vehicular Technology Conference (VTC Spring), 2012Co-Authors: Panagiotis Paschalidis, Kim Mahler, Andreas Kortke, Michael Peter, Wilhelm KeusgenAbstract:In this paper we present a statistical evaluation of the lifetime of Multipath Components for the vehicular radio channel. We introduce a new identification and tracking algorithm. The algorithm follows a geometrical approach exploiting the high scatterer resolution in the measurement data and takes as an estimation basis considerations on the relative movement of the scatterer. We subsequently apply the algorithm to evaluate the measured data. We use wideband channel measurement data collected at urban street intersections under NLOS-conditions. We sequentially evaluate weighted interrelations between detected contributions in the time-delay domain and decide on common underlying scatterers or not. We suggest a classification of distinct and diffuse contributions by means of a threshold with respect to lifetime and discuss on their temporal characteristics, based on an exemplary measurement with typical values. In specific we characterize the lifetime by means of a probability density function and further examine the relation of lifetime and power level of the Multipath contribution.
Zhangdui Zhong - One of the best experts on this subject based on the ideXlab platform.
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a novel power weighted Multipath Component clustering algorithm based on spectral clustering
Vehicular Technology Conference, 2020Co-Authors: Chen Huang, Zhangdui ZhongAbstract:In the real propagation environments, Multipath Components (MPCs) in wireless channel usually exist as clusters. Cluster based structure of MPCs has been widely used in wireless channel modeling. In this paper, a novel MPC clustering algorithm is proposed based on spectral clustering. Considering that MPCs having strong power should usually be grouped into different clusters, the algorithm introduces a power-weighted processing to identify the similarity of each MPC. The process of weighting the power is conducted by generating similarity matrix using the full link method of Gaussian kernel function in the traditional spectral clustering algorithm. In order to achieve high clustering accuracy, the dimensionality reduction method of Laplacian Eigenmap is decomposed by using the normalized cut method, the obtained eigenvectors are re-clustered to cut the generated similarity matrix for MPC clustering. In the simulation results, it is found that this algorithm can well separate MPCs with high powers into different clusters and achieves better clustering performance compared with KPowerMeans, Kmeans, and the traditional spectral clustering algorithms.
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VTC Spring - A Novel Power Weighted Multipath Component Clustering Algorithm Based on Spectral Clustering
2020 IEEE 91st Vehicular Technology Conference (VTC2020-Spring), 2020Co-Authors: Chen Huang, Zhangdui ZhongAbstract:In the real propagation environments, Multipath Components (MPCs) in wireless channel usually exist as clusters. Cluster based structure of MPCs has been widely used in wireless channel modeling. In this paper, a novel MPC clustering algorithm is proposed based on spectral clustering. Considering that MPCs having strong power should usually be grouped into different clusters, the algorithm introduces a power-weighted processing to identify the similarity of each MPC. The process of weighting the power is conducted by generating similarity matrix using the full link method of Gaussian kernel function in the traditional spectral clustering algorithm. In order to achieve high clustering accuracy, the dimensionality reduction method of Laplacian Eigenmap is decomposed by using the normalized cut method, the obtained eigenvectors are re-clustered to cut the generated similarity matrix for MPC clustering. In the simulation results, it is found that this algorithm can well separate MPCs with high powers into different clusters and achieves better clustering performance compared with KPowerMeans, Kmeans, and the traditional spectral clustering algorithms.
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On Modeling of Dense Multipath Component for Indoor Massive MIMO Channels
IEEE Antennas and Wireless Propagation Letters, 2019Co-Authors: Mi Yang, Zhangdui ZhongAbstract:Elaborate channel modeling is an essential prerequisite for design, testing, and improvement of the massive multiple-input–multiple-output (MIMO) system. In this letter, dense Multipath Component (DMC) modeling for massive MIMO channels is presented based on measurement campaigns in three different indoor scenarios. The parameters for DMC are extracted by applying a RiMAX-based estimator. The distance-dependence and the variance behaviors of the DMC parameters across the large-scale array are analyzed and modeled. Moreover, the model validation is performed by using an empirical cluster-based massive MIMO channel model. Entropy capacity, condition number, channel ellipticity, and root-mean-square delay spread, which reflect the spatial structure and Multipath richness of the channel, are used as the validation metrics. The validation shows that the incorporation of DMC can significantly improve the accuracy of channel modeling.
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cluster based 3 d channel modeling for massive mimo in subway station environment
IEEE Access, 2018Co-Authors: Jianzhi Li, Mi Yang, Ruisi He, Bo Ai, Qi Wang, Bei Zhang, Zhangdui ZhongAbstract:In this paper, a massive multiple-input multiple-output (MIMO) channel measurement campaign with 256-element virtual rectangular array at the base station was conducted. The typical hotspot scenario, subway station, is considered, and the measurements were conducted at 6 GHz with a bandwidth of 100 MHz. A hybrid clustering approach is proposed to characterize the cluster evolution over the large-scale array. In the hybrid approach, we apply the space-alternating generalized expectation maximization algorithm to estimate the Multipath Components (MPCs), and use the Multipath Component distance-based tracking algorithm and the KPowerMeans algorithm for MPCs tracking and clustering. A cluster partition algorithm is further proposed to adjudge the clusters association over the array, and output the final clustering results. Under such a scheme, cluster-based model parameters are provided with detailed analysis. The extracted parameters include overall angle distribution, global angular spread, inter-cluster parameters, and intra-cluster parameters. The obtained model parameters can be fed into the new channel simulator for massive MIMO. This is useful for the design and application of the practical massive MIMO system in the future.
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a novel power weighted Multipath Component tracking algorithm
URSI General Assembly and Scientific Symposium, 2017Co-Authors: Chen Huang, Zhangdui ZhongAbstract:In mobile communications, the wireless channel has been widely considered to be time-variant. To statistically model the time-variant channels, a power weighted dynamic multi-path Components (MPCs) tracking algorithm is proposed in this paper, which is based on multiple-target tracking. The problem of seeking potential position is considered as a maximum a posteriori (MAP) estimation in a Markov random process, which can be solved by using the maximum probability. In order to reflect the real condition of channels and improve accuracy of algorithm, statistical behaviors of azimuth, delay, and power of MPCs are generated for algorithm validation by using different distributions according to the dynamic measurements in real-world. Our method is finally validated by using the simulated dynamic channels and is found to have good performance.
Wenhui Xiong - One of the best experts on this subject based on the ideXlab platform.
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the 5 ghz airport surface area channel part ii measurement and modeling results for small airports
IEEE Transactions on Vehicular Technology, 2008Co-Authors: David W. Matolak, Wenhui XiongAbstract:We describe results from a channel measurement and modeling campaign for the airport surface environment in the 5-GHz band. Using a 50-MHz bandwidth test signal, thousands of power delay profiles (PDPs) were obtained and processed to develop empirical tapped-delay line statistical channel models for large airports. A log-distance path loss model was also developed. The large airport surface channel is classified into three propagation regions, and models are presented for each of the regions for two values of bandwidth. Values of the median root-mean-square (RMS) delay spread range from 500 to 1000 ns for these airports, with the 90 th percentile RMS delay spreads being approximately 1.7 ms. Corresponding correlation bandwidths (i.e., correlation value 1/2) range from approximately 1.5 MHz in non-line-of-sight (NLOS) settings to 17.5 MHz in line-of-sight (LOS) settings. Two types of statistical nonstationarity were also observed: 1) Multipath Component persistence and 2) propagation region transitions. We provide the Multipath Component probability of occurrence models and describe Markov chains that are used for modeling both phenomena. Channel tap amplitude statistics are also provided, using the flexible Weibull probability density function (pdf). This pdf was found to best fit fading tap amplitude data, particularly for frequently observed severe fading, which is characterized by fade probabilities that are worse than the commonly used Rayleigh model. Fading parameters equivalent to Nakagami-m-model values of m near 0.7 were often observed (with m = 1 being Rayleigh and m < 1 being worse than Rayleigh). We also provide channel tap amplitude correlation coefficients, which typically range from 0.1 to 0.4 but occasionally take values greater than 0.7.
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The 5-GHz Airport Surface Area Channel—Part II: Measurement and Modeling Results for Small Airports
IEEE Transactions on Vehicular Technology, 2008Co-Authors: David W. Matolak, Wenhui XiongAbstract:We describe results from a channel measurement and modeling campaign for the airport surface environment in the 5-GHz band. Using a 50-MHz bandwidth test signal, thousands of power delay profiles (PDPs) were obtained and processed to develop empirical tapped-delay line statistical channel models for large airports. A log-distance path loss model was also developed. The large airport surface channel is classified into three propagation regions, and models are presented for each of the regions for two values of bandwidth. Values of the median root-mean-square (RMS) delay spread range from 500 to 1000 ns for these airports, with the 90 th percentile RMS delay spreads being approximately 1.7 ms. Corresponding correlation bandwidths (i.e., correlation value 1/2) range from approximately 1.5 MHz in non-line-of-sight (NLOS) settings to 17.5 MHz in line-of-sight (LOS) settings. Two types of statistical nonstationarity were also observed: 1) Multipath Component persistence and 2) propagation region transitions. We provide the Multipath Component probability of occurrence models and describe Markov chains that are used for modeling both phenomena. Channel tap amplitude statistics are also provided, using the flexible Weibull probability density function (pdf). This pdf was found to best fit fading tap amplitude data, particularly for frequently observed severe fading, which is characterized by fade probabilities that are worse than the commonly used Rayleigh model. Fading parameters equivalent to Nakagami-m-model values of m near 0.7 were often observed (with m = 1 being Rayleigh and m < 1 being worse than Rayleigh). We also provide channel tap amplitude correlation coefficients, which typically range from 0.1 to 0.4 but occasionally take values greater than 0.7.
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MobiQuitous - Channel Modeling for V2V Communications
2006 3rd Annual International Conference on Mobile and Ubiquitous Systems - Workshops, 2006Co-Authors: David W. Matolak, Wenhui XiongAbstract:In this paper we describe results of a channel measurement campaign for modeling the V2V channel. After review of applications, potential frequency bands, and related work, we describe the measurements and results for delay spreads and Multipath Component fading amplitudes and correlations, made in multiple V2V environments. We also note how the V2V channel can differ appreciably from other common terrestrial (e.g., cellular) channels. We describe considerations used in developing the statistical channel models for these environments, and provide some example measurement and modeling results that should be useful for system designers in future V2V applications.
Panagiotis Paschalidis - One of the best experts on this subject based on the ideXlab platform.
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statistical evaluation of Multipath Component lifetime in the car to car channel at urban street intersections based on geometrical tracking
Vehicular Technology Conference, 2012Co-Authors: Panagiotis Paschalidis, Kim Mahler, Andreas Kortke, Michael Peter, Wilhelm KeusgenAbstract:In this paper we present a statistical evaluation of the lifetime of Multipath Components for the vehicular radio channel. We introduce a new identification and tracking algorithm. The algorithm follows a geometrical approach exploiting the high scatterer resolution in the measurement data and takes as an estimation basis considerations on the relative movement of the scatterer. We subsequently apply the algorithm to evaluate the measured data. We use wideband channel measurement data collected at urban street intersections under NLOS-conditions. We sequentially evaluate weighted interrelations between detected contributions in the time-delay domain and decide on common underlying scatterers or not. We suggest a classification of distinct and diffuse contributions by means of a threshold with respect to lifetime and discuss on their temporal characteristics, based on an exemplary measurement with typical values. In specific we characterize the lifetime by means of a probability density function and further examine the relation of lifetime and power level of the Multipath contribution.
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VTC Spring - Statistical Evaluation of Multipath Component Lifetime in the Car-to-Car Channel at Urban Street Intersections Based on Geometrical Tracking
2012 IEEE 75th Vehicular Technology Conference (VTC Spring), 2012Co-Authors: Panagiotis Paschalidis, Kim Mahler, Andreas Kortke, Michael Peter, Wilhelm KeusgenAbstract:In this paper we present a statistical evaluation of the lifetime of Multipath Components for the vehicular radio channel. We introduce a new identification and tracking algorithm. The algorithm follows a geometrical approach exploiting the high scatterer resolution in the measurement data and takes as an estimation basis considerations on the relative movement of the scatterer. We subsequently apply the algorithm to evaluate the measured data. We use wideband channel measurement data collected at urban street intersections under NLOS-conditions. We sequentially evaluate weighted interrelations between detected contributions in the time-delay domain and decide on common underlying scatterers or not. We suggest a classification of distinct and diffuse contributions by means of a threshold with respect to lifetime and discuss on their temporal characteristics, based on an exemplary measurement with typical values. In specific we characterize the lifetime by means of a probability density function and further examine the relation of lifetime and power level of the Multipath contribution.
Kim Mahler - One of the best experts on this subject based on the ideXlab platform.
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statistical evaluation of Multipath Component lifetime in the car to car channel at urban street intersections based on geometrical tracking
Vehicular Technology Conference, 2012Co-Authors: Panagiotis Paschalidis, Kim Mahler, Andreas Kortke, Michael Peter, Wilhelm KeusgenAbstract:In this paper we present a statistical evaluation of the lifetime of Multipath Components for the vehicular radio channel. We introduce a new identification and tracking algorithm. The algorithm follows a geometrical approach exploiting the high scatterer resolution in the measurement data and takes as an estimation basis considerations on the relative movement of the scatterer. We subsequently apply the algorithm to evaluate the measured data. We use wideband channel measurement data collected at urban street intersections under NLOS-conditions. We sequentially evaluate weighted interrelations between detected contributions in the time-delay domain and decide on common underlying scatterers or not. We suggest a classification of distinct and diffuse contributions by means of a threshold with respect to lifetime and discuss on their temporal characteristics, based on an exemplary measurement with typical values. In specific we characterize the lifetime by means of a probability density function and further examine the relation of lifetime and power level of the Multipath contribution.
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VTC Spring - Statistical Evaluation of Multipath Component Lifetime in the Car-to-Car Channel at Urban Street Intersections Based on Geometrical Tracking
2012 IEEE 75th Vehicular Technology Conference (VTC Spring), 2012Co-Authors: Panagiotis Paschalidis, Kim Mahler, Andreas Kortke, Michael Peter, Wilhelm KeusgenAbstract:In this paper we present a statistical evaluation of the lifetime of Multipath Components for the vehicular radio channel. We introduce a new identification and tracking algorithm. The algorithm follows a geometrical approach exploiting the high scatterer resolution in the measurement data and takes as an estimation basis considerations on the relative movement of the scatterer. We subsequently apply the algorithm to evaluate the measured data. We use wideband channel measurement data collected at urban street intersections under NLOS-conditions. We sequentially evaluate weighted interrelations between detected contributions in the time-delay domain and decide on common underlying scatterers or not. We suggest a classification of distinct and diffuse contributions by means of a threshold with respect to lifetime and discuss on their temporal characteristics, based on an exemplary measurement with typical values. In specific we characterize the lifetime by means of a probability density function and further examine the relation of lifetime and power level of the Multipath contribution.
