Search

In vehicular environments, the scattering environment can change very rapidly, owing to the mobility of the Tx and Rx vehicles, the relatively low height of the antennas and the potentially large number of scatterers in the surrounding environment. Vehicular radio propagation channels thus differ significantly from those of other wireless cellular networks, so that dedicated measurement campaigns and realistic radio propagation channel models are required to fully exploit their potentialities. The main contributions of this thesis are summarized as follows: - Two measurement campaigns of MIMO vehicular radio propagation channels were conducted at 5.3 GHz, - The validity of the WSS and US assumptions is assessed using the CMD, which characterizes the amount of change in the spatial structure of MIMO radio propagation channels. Stationarity distances and frequency bandwidth are 10 to 40 m long and 40 to 50 MHz wide, respectively, depending on the variability and richness of the scattering environment, - The non-stationary fading statistics are characterized stochastically, in terms of Ricean K-factor and RMS delay spread. Their time- and space-variations are strongly related to changes in the richness of the scattering environment and on the presence (or not) of a strong LoS component. They are modeled by multi-modal Gaussian distributions, - A vehicular GSCM is proposed, in which each scatterer is defined and characterized separately: the radio wave propagation with simplified ray-tracing tools and the scattering aspects with a classical fading model. The diffuse scattering is modeled in a purely stochastic manner. The GSCM is then completely parameterized and validated for SISO systems., (FSA - Sciences de l'ingénieur) -- UCL, 2013

This paper reviews recently published results on multiple input multiple output (MIMO) channel modeling. Both narrowband and wideband models are considered. We distinguish between two main approaches to MIMO channel modeling, that is,. physically based and nonphysically based modeling. The nonphysical models primarily rely on the statistical characteristics of the MIMO channels obtained from the measured data, while the physical models describe the MIMO channel (or its distribution) via some physical parameters. We briefly review different MIMO channel models and discuss their relationships. Some interesting aspects will be described in more detail and we note areas in which few results are available., QC 20100525

This paper reviews recently published results on multiple input multiple output (MIMO) channel modeling. Both narrowband and wideband models are considered. We distinguish between two main approaches to MIMO channel modeling, that is, physically based and nonphysically based modeling. The nonphysical models primarily rely on the statistical characteristics of the MIMO channels obtained from the measured data, while the physical models describe the MIMO channel (or its distribution) via some physical parameters. We briefly review different MIMO channel models and discuss their relationships. Some interesting aspects will be described in more detail and we note areas in which few results are available. Copyright © 2002 John Wiley & Sons, Ltd.