Search results for "rayleigh"

Statistical Analysis of the Channel Capacity Outage Intervals in Massive MIMO Systems with OSTBC over Rayleigh Fading Channels

2015

This paper studies approximate solutions for the statistical properties of the outage intervals of the instantaneous capacity in massive multiple- input multiple- output (MIMO) sys- tems with orthogonal space-time block code (OSTBC) over Rayleigh fading channels. We take advantage from the fact that the probability density function (PDF) of the channel power gain can be approximated by a left-truncated Gaussian distribution if the number of transmit and receive antennas is large. Assuming a symmetrical Doppler power spectral density (PSD), a closed- form expression is presented for the Rice probability function of the outage durations. This function, in general, approximates the PDF of the …

The influence of severity of fading on the statistical properties of the capacity of Nakagami-m channels with MRC and EGC

2010

In this article, we have studied the statistical properties of the capacity of Nakagami-m channels when spatial diversity combining, such as maximal ratio combining (MRC) and equal gain combining (EGC), is employed at the receiver. The presented results provide insight into the statistical properties of the channel capacity under a wide range of fading conditions in wireless links using L-branch diversity combining techniques. We have derived closed-form analytical expressions for the probability density function (PDF), cumulative distribution function (CDF), level-crossing rate (LCR), and average duration of fades (ADF) of the channel capacity. The statistical properties of the capacity ar…

Self-consistent Euclidean-random-matrix theory

2019

Hyper-Rayleigh scattering and two-photon luminescence of phenylamine- indandione chromophores

2012

Based on results of quantum chemical (QC) screening, we put under research several phenylamine indane-1,3-dione derivatives including octupolar NLO chromophore A3BI. According to these calculations, molecular first hyperpolarizability (βHRS) should be enhanced upon replacement of methyl substituents with phenyl groups. Surprisingly, βHRS values obtained in our measurements by hyper-Rayleigh scattering (HRS) are much higher than one could expect from QC. Bearing in mind that two-photon luminescence (TPL) is usual cause for overestimation of βHRS in HRS measurements, we have accomplished investigations of TPL properties of these compounds. All investigated triphenylamine derivatives exhibit s…

Deriving Seismic Surface Rotations for Engineering Purposes

2006

Surface waves on cylindrical solids: numerical and experimental study.

2013

The use of Rayleigh waves enables the solution of several important inspection problems. Propagation of surface waves along straight boundaries has been properly studied but investigations about their propagation on cylindrical surfaces are not sufficient, despite they can be still of interest for NDE applications. It has been proved experimentally that a surface wave pulse suffers a phase shift during its propagation along a cylindrical surface. A numerical approach has been developed to efficiently study these effects for different materials, curvatures and frequencies. This study can help the scientific community to better understand the phenomenon, quite complex and not yet fully explor…

Synthetic aperture microscopy using off-axis illumination and polarization coding

2007

A new method to improve the resolution of optical imaging systems beyond the classical Rayleigh resolution limit is presented. The technique relies on synthetic aperture generation in three stages. The first one (encoding stage) uses an illumination procedure that combines both on-axis and off-axis illumination beams with different polarization states onto the object. After the imaging system, a second stage (decoding stage) allows the recovering of the encoded spatial-frequency object information by means of an interferometric configuration based on the polarization coding carried out in the previous stage. Finally, a third stage (digital post-processing stage) is used to generate a synthe…

Real time monitoring of water level and temperature in storage fuel pools through optical fibre sensors

2017

AbstractWe present an innovative architecture of a Rayleigh-based optical fibre sensor for the monitoring of water level and temperature inside storage nuclear fuel pools. This sensor, able to withstand the harsh constraints encountered under accidental conditions such as those pointed-out during the Fukushima-Daiichi event (temperature up to 100 °C and radiation dose level up to ~20 kGy), exploits the Optical Frequency Domain Reflectometry technique to remotely monitor a radiation resistant silica-based optical fibre i.e. its sensing probe. We validate the efficiency and the robustness of water level measurements, which are extrapolated from the temperature profile along the fibre length, …

Transient Development of Rayleigh-Bénard Convection: a TLC Study

2011

Caracterización proteómica de la interacción y la inserción de proteínas de membrana

2019

Las proteínas de membrana tienen funciones muy diversas en la célula, desde controlar el tráfico molecular hasta facilitar la transducción de señales. Sin embargo, el estudio de estas proteínas supone todo un reto por sus particulares características fisico-químicas. Su naturaleza hidrofóbica requiere un elevado control durante su síntesis. Uno de los pasos críticos en esta síntesis es la inserción en la bicapa lipídica. Generalmente, este proceso se produce a través de un mecanismo (co-traduccional) acoplado al proceso de traducción. Esta vía co-traduccional ha sido ampliamente estudiada y la maquinaria implicada en el proceso se conoce con bastante profundidad. Sin embargo, algunas proteí…