scholarly journals On the Statistical Properties of Nakagami-Hoyt Vehicle-to-Vehicle Fading Channel under Nonisotropic Scattering

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Muhammad Imran Akram ◽  
Asrar U. H. Sheikh
Keyword(s):  
Channel Model ◽  
Time Correlation ◽  
Time Correlation Function ◽  
Statistical Properties ◽  
Computation Method ◽  
Level Crossing Rate ◽  
Vehicle To Vehicle ◽  
Power Spectral ◽  
Time Autocorrelation Function ◽  
Nonisotropic Scattering

This paper presents the statistical properties of the vehicle-to-vehicle Nakagami-Hoyt (Nakagami-q) channel model under non-isotropic condition. The spatial time correlation function (STCF), the power spectral density (PSD), squared time autocorrelation function (SQCF), level crossing rate (LCR), and the average duration of Fade (ADF) of the Nakagami-Hoyt channel have been derived under the assumption that both the transmitter and receiver are nonstationary having nonomnidirectional antennas. A simulator that uses the inverse-fast-fourier-transform- (IFFT-) based computation method is designed for this model. The simulator and analytical results are compared.

scholarly journals Statistical Characterization of Novel 3D Cluster-Based MIMO Vehicle-to-Vehicle Models for Urban Street Scattering Environments

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Xin Chen ◽  
Yong Fang ◽  
Yanzan Sun ◽  
Yuntian Pan ◽  
Weidong Xiang
Keyword(s):  
Channel Model ◽  
Reference Model ◽  
Three Dimensional ◽  
Measurement Data ◽  
Time Correlation ◽  
Time Correlation Function ◽  
Statistical Characterization ◽  
Urban Street ◽  
Vehicle To Vehicle ◽  
V2v Communications

We develop a novel three-dimensional (3D) cluster-based channel model for vehicle-to-vehicle (V2V) communications under the scenarios of urban street scattering environments. The proposed model combines the flexibility of geometrical channel models with the existing state-of-the-art 3D V2V models. To provide an accurate representation of specific locations and realistic V2V fading environments in a computationally manageable fashion, all clusters are divided into three groups of use cases including “ahead,” “between,” and “behind” clusters according to the relative locations of clusters. Using the proposed V2V model, we first derive the closed-form expressions of the channel impulse response (CIR), including the line-of-sight (LoS) components and cluster components. Subsequently, for three categories of clusters, the corresponding statistical properties of the reference model are studied. We additionally derive the expressions of the 3D space-time correlation function (STCF), the autocorrelation function (ACF), and 2D STCF. Finally, comparisons with on-road measurement data and numerical experiments demonstrate the validity and effectiveness of the proposed 3D cluster-based V2V model.

scholarly journals A Semiempirical MIMO Channel Model in Obstructed Viaduct Scenarios on High-Speed Railway

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Tao Zhou ◽  
Cheng Tao ◽  
Liu Liu ◽  
Zhenhui Tan
Keyword(s):  
High Speed ◽  
Channel Model ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Time Correlation ◽  
Time Correlation Function ◽  
Mimo Channel ◽  
High Speed Railway ◽  
Single Input Single Output ◽  
Single Output

A semiempirical multiple-input multiple-output (MIMO) channel model is proposed for high-speed railway (HSR) viaduct scenarios. The proposed MIMO model is based on the combination of realistic single-input single-output (SISO) channel measurement results and a theoretical geometry-based stochastic model (GBSM). Temporal fading characteristics involvingK-factor and Doppler power spectral density (PSD) are derived from the wideband measurement under an obstructed viaduct on Zhengzhou-Xi’an HSR in China. The GBSM composed of a one-ring model and an elliptical model is employed to describe the entire propagation environment. Environment-related parameters in the GBSM are determined by the measured temporal fading properties. And a close agreement is achieved between the model results and measured data. Finally, a deterministic simulation model is established to perform the analysis of the space-time correlation function, the space-Doppler PSD, and the channel capacity for the measured scenario. This model is more realistic and particularly beneficial for the performance evaluation of MIMO systems in HSR environments.

scholarly journals Simulation and Analysis of Extended Spatial Channel Model in Vehicle-to-Vehicle Communication Environments

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xin Chen ◽  
Yaolin Zhu ◽  
Yong Fang
Keyword(s):  
Channel Model ◽  
Reference Model ◽  
Statistical Properties ◽  
Death Process ◽  
Closed Form Expression ◽  
Vehicle Communication ◽  
Vehicle To Vehicle ◽  
Communication Environments ◽  
Spatial Channel Model ◽  
V2v Communications

In this paper, an extension spatial channel model (SCM) for vehicle-to-vehicle (V2V) communications is proposed. To efficiently illustrate the real-world scenarios and reflect nonstationary properties of V2V channels, all effective scattering objects are subdivided into three categories of clusters according to the relative position of clusters. Besides, a birth-death process is introduced to model the appearance and disappearance of clusters on both the array and time axes. Their impacts on V2V channels are investigated via statistical properties including correlation functions. Additionally, a closed-form expression of channel impulse response (CIR) is derived from an extension SCM and cluster-based models. Furthermore, the spatial and frequency statistical properties of the reference model are thoroughly investigated. Finally, simulation results show that the proposed SCM V2V model is in close agreement with previously reported results, thereby validating the accuracy and effectiveness of the proposed model.

scholarly journals A General 3D Nonstationary Vehicle-to-Vehicle Channel Model Allowing 3D Arbitrary Trajectory and 3D-Shaped Antenna Array

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Qiuming Zhu ◽  
Weidong Li ◽  
Ying Yang ◽  
Dazhuan Xu ◽  
Weizhi Zhong ◽  
...  
Keyword(s):  
Antenna Arrays ◽  
Channel Model ◽  
Multiple Input Multiple Output ◽  
Temporal Correlation ◽  
Statistical Properties ◽  
Vehicle To Vehicle ◽  
Input Multiple Output ◽  
V2v Communications ◽  
Doppler Power ◽  
Mobile Receiver

Most of the existing channel model for multiple-input multiple-output (MIMO) vehicle-to-vehicle (V2V) communications only considered that the terminals were equipped with linear antenna arrays and moved with fixed velocities. Nevertheless, under the realistic environment, those models are not practical since the velocities and trajectories of mobile transmitter (MT) and mobile receiver (MR) could be time-variant and unpredictable due to the complex traffic conditions. This paper develops a general 3D nonstationary V2V channel model, which is based on the traditional geometry-based stochastic models (GBSMs) and the twin-cluster approach. In contrast to the traditional models, this new model is characterized by 3D scattering environments, 3D antenna arrays, and 3D arbitrary trajectories of both terminals and scatterers. The calculating methods of channel parameters are also provided. In addition, the statistical properties, i.e., spatial-temporal correlation function (STCF) and Doppler power spectrum density (DPSD), are derived in detail. Simulation results have demonstrated that the output statistical properties of the proposed model agree well with the theoretical and measured results, which verifies the effectiveness of theoretical derivations and channel model as well.

Rate Constants, Reactive Flux

2018 ◽  
Author(s):  
Niels Engholm Henriksen ◽  
Flemming Yssing Hansen
Keyword(s):  
Correlation Function ◽  
Rate Constant ◽  
Cross Sections ◽  
Time Correlation ◽  
Time Correlation Function ◽  
Exact Expression ◽  
Reaction Cross ◽  
Dividing Surface ◽  
Definition Of ◽  
Reactive Flux

This chapter discusses a direct approach to the calculation of the rate constant k(T) that bypasses the detailed state-to-state reaction cross-sections. The method is based on the calculation of the reactive flux across a dividing surface on the potential energy surface. Versions based on classical as well as quantum mechanics are described. The classical version and its relation to Wigner’s variational theorem and recrossings of the dividing surface is discussed. Neglecting recrossings, an approximate result based on the calculation of the classical one-way flux from reactants to products is considered. Recrossings can subsequently be included via a transmission coefficient. An alternative exact expression is formulated based on a canonical average of the flux time-correlation function. It concludes with the quantum mechanical definition of the flux operator and the derivation of a relation between the rate constant and a flux correlation function.

Turbulence functions useful for probes (space–time correlation) and for scattering (wave-number–frequency spectrum) analysis

1968 ◽  
Vol 46 (23) ◽  
pp. 2683-2702 ◽  
Author(s):  
I. P. Shkarofsky
Keyword(s):  
Characteristic Size ◽  
Time Correlation ◽  
Exponential Model ◽  
Time Correlation Function ◽  
Maximum Energy ◽  
Confluent Hypergeometric Function ◽  
Space Time ◽  
Wave Number ◽  
Taylor’S Hypothesis ◽  
Number Frequency

The wave-number–frequency dependent spectral function, S(k, ω), and the space–time correlation function, C(r, t), are considered in a turbulent flowing plasma. The decay mechanisms are associated with either velocity fluctuations about the mean convection velocity or diffusion effects or attachment, or combinations of these, including the Brownian motion model. The ψ(k, ω) function, which is the ratio of S(k, ω) to its frequency-integrated value, depends on the mechanism and exhibits a profile which can be Gaussian, Lorentzian, a Z function, a Hermite polynomial modification of the Gaussian, or a confluent hypergeometric function. Anisotropic forms are also considered.The function C(r, t), obtained by convolving ψ (r, t) with C(r), the space autocorrelation function, is next considered. Adopting a Gaussian or an exponential model (which may be anisotropic) for C(r), we illustrate C(r, t) forms, which can readily be manipulated. Furthermore, letting r = 0, we derive two conditions for the applicability of Taylor's hypothesis. The assumption of frozen flow is not necessary, only that the root-mean-square Lagrangian displacement in a given time, associated with the decay, be much smaller than both the flow distance and the characteristic size of blobs having maximum energy.

Two-body dynamics in fluids as probed by interaction-induced light scattering

1981 ◽  
Vol 59 (10) ◽  
pp. 1504-1509 ◽  
Author(s):  
U. Balucani ◽  
R. Vallauri
Keyword(s):  
Correlation Function ◽  
Light Scattering ◽  
Time Correlation ◽  
Time Correlation Function ◽  
Simulation Experiments ◽  
Particle Pairs ◽  
Body Dynamics ◽  
Atomic Fluids ◽  
Relative Dynamics

The relative dynamics of particle pairs in fluids is investigated both theoretically and by simulation experiments. The physical implications of this analysis are important in all interaction-induced phenomena and illustrated in the case of the pair time correlation function relevant to collision-induced light scattering in atomic fluids.

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