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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 33 for “"Radio-wave propagation"”.
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Tropospheric Radio Wave Propagation Beyond the Horizon
Made available in DSpace on 2014-12-04T21:02:39Z (GMT). No. of bitstreams: 1 0009072.pdf: 4211647 bytes, checksum: 4eceebef4ab8c81549514712698d0879 (MD5) Previous issue date: 1954
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Terrestrial radio wave propagation at millimeter-wave frequencies
This research focuses on radio wave propagation at millimeter-wave frequencies. A measurement based channel characterization approach is taken in the investigation. First, measurement techniques are analyzed. Three types of measurement systems are designed, and implemented in measurement campaigns: …
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GIS Aided Radio Wave Propagation Modeling and Analysis
The analysis of radio wave propagation is a crucial part in designing an efficient wireless communication system. The Geographic Information System (GIS) can be incorporated into this procedure because most of the factors in radio wave propagation are geographic features. In this research, a …
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Novel Site-Specific Techniques for Predicting Radio Wave Propagation
… various aspects related to site-specific propagation prediction using ray tracing techniques. Propagation prediction based on ray tracing techniques requires that all the different physical objects, which affect the propagation of radio waves, be modeled. The first part of the thesis …
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Radio Wave Propagation Measurements and Modeling for Land Mobile Satellite Systems
… is conditioned by the characteristics of the propagation path between a satellite and mobile users. The most important propagation effect in land mobile satellite system is roadside attenuation of the signals due to vegetation or urban structures. System designers should have the most reliable …
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Using Light Detection and Ranging (LiDAR) Imagery to Model Radio Wave Propagation
… data set for modeling near line-of-sight (LOS) propagation at higher frequencies, specifically 27.810 GHz. than a USGS digital elevation model (DEM). In addition, the study tested for significant differences in LiDAR elevation data created at various resolutions ranging from 1 to 100 meters. …
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Indoor wide band radio wave propagation measurements and models at 1.3 ghz and 4.0 ghz
An extensive radio wave propagation measurement campaign was conducted at 1.3 GHz and 4.0 GHz inside four buildings, including a sports arena, a modern closed-plan office building, and two dissimilar, open-plan factories. Measurements were recorded at 57 locations using base station antenna heights …
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Multiple scattering of electromagnetic waves by distributions of particles with applications to radio wave propagation through precipitation
… two-frequency BetheSaltpeter equation for waves propagating in a distribution of spatially pair correlated absorptive scatterers. From these equations a systematic transition is made to a two-frequency radiative transfer equation suitable forpusled scalar waves in the presence of a tenuous …
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Validation of the ITU-R P series radio wave propagation model for millimetre wave V-Band (60GHz) line-of-sight point-to-point short distance link
Millimetre-wave communication systems have a very high potential to become mobile technology of choice for future 4G and 5G network architectures, which has led to many researchers carrying out studies regarding the effects of the atmosphere on radio propagation. There is growing interest in the …
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High Frequency Radio Wave Transionospheric Propagation Polarization Studies from the RRI-SuperDARN Experiment
… One of the 8 instruments it carries is the Radio Receiver Instrument (RRI) which is a passive cross-dipole radio observation instrument. The RRI detects incoming HF (High Frequency) radio waves and measures the polarization information (such as orientation angle and ellipticity angle) of the …
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Effects of the troposphere upon radio communications and implications for weather measurement
… to use observations of Very High Frequency (VHF) radio wave propagation to estimate the refractive index of air over a propagation path and subsequently the pressure, temperature, and water vapour. This can be accomplished by transmitting a known signal from one spatial location to another, and …
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Electrodynamic Green's Functions in Layered Media: Accurate Closed -Form Approximations for Both Electric and Magnetic Sources
… making it suitable for applications ranging from radio wave propagation above Earth, to the design of planar microwave/millimeter-wave frequencies and of integrated optical waveguides. In addition, special attention was paid to making the tool as transparent as possible to the user. In this …
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Understanding and predicting urban propagation losses
… to communicate, is a complete understanding of radio wave propagation and the positive and negative effects of spreading and propagation losses. In a communication link, or radio wave transmission, several sources of degradation are mathematically accounted for, to include losses due to …
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A Grid based Indoor Radiolocation Technique Based on Spatially Coherent Path Loss Model
This thesis presents a grid-based indoor radiolocation technique based on a Spatially Coherent Path Loss Model (SCPL). SCPL is a path loss model which characterizes the radio wave propagation in an environment by solely using Received Signal Strength (RSS) fingerprints. The propagation of the radio …
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Wideband Propagation Measurement Results, Simulation Models, and Processing Techniques for a Sliding Correlator Measurement System
Radio wave propagation measurements provide a way to accurately and reliably characterize environments to assist in the development and optimization of wireless communication systems. As digital radio systems occupy wider bandwidths and use multipath signal combining to enhance quality of service, …
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Microwave multipath resolution in microcellular channels
The objective of this research is to compare radio channel impulse response measurements with site-specific radio wave propagation prediction techniques. A wide band spread spectrum measurement system was developed, and desirable measurement locations were selected on the Virginia Tech campus. …
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Characterizing radio channels : the science and technology of propagation and interference, 1900-1935
… rise to such a transformation: the studies of radio-wave propagation and the treatments of radio interferences in early twentieth-century America and Western Europe. The part on propagation examines the debate between the surface diffraction theory and the atmospheric reflection theory for long …
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Radio Channel Measurements and Modeling for Smart Antenna Array Systems Using a Software Radio Receiver
… presents research performed in the areas of radio wave propagation measurement and modeling, smart antenna arrays, and software-defined radio development. A four-channel, wideband, software-defined receiver was developed to serve as a test bed for wideband measurements and antenna array …
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A discrete RET Model for Micro- and Millimetre Wave Propagation through Vegetation
… design and implementation on the availability of radiowave propagation models. In the particular case of land mobile radio systems and wireless fixed access systems, obstacles in the form of vegetation volumes, e.g formations of trees, are likely to influence radio propagation, giving rise to …
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Extraction of Input Parameters for the Theory of Radiative Energy Transfer Using Deconvolution.
… requires accurate models for characterising radiowave propagation when affected by the presence of a variety of obstacles. In particular if the obstacles take the shape of vegetation volumes, like single trees or groups of trees and are present in the radio path, they give rise to absorption …
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