Near-field scattering methods applied to radio-propagation modeling in urban outdoor environments

2007 ◽  
Author(s):  
E. G. Papkelis ◽  
P. V. Frangos ◽  
H. T. Anastassiu ◽  
B. A. Massinas
Keyword(s):  
Near Field ◽  
Radio Propagation ◽  
Propagation Modeling ◽  
Outdoor Environments

Brief review on PE method application to propagation channel modeling in sea environment

2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Irina Sirkova
Keyword(s):  
Wave Propagation ◽  
Fourier Transform ◽  
Parabolic Equation ◽  
Initial Conditions ◽  
Channel Modeling ◽  
Radio Propagation ◽  
Propagation Channel ◽  
Tropospheric Propagation ◽  
Propagation Modeling ◽  
Wave Propagation Modeling

AbstractThis work provides an introduction to one of the most widely used advanced methods for wave propagation modeling, the Parabolic Equation (PE) method, with emphasis on its application to tropospheric radio propagation in coastal and maritime regions. The assumptions of the derivation, the advantages and drawbacks of the PE, the numerical methods for solving it, and the boundary and initial conditions for its application to the tropospheric propagation problem are briefly discussed. More details are given for the split-step Fourier-transform (SSF) solution of the PE. The environmental input to the PE, the methods for tropospheric refractivity profiling, their accuracy, limitations, and the average refractivity modeling are also summarized. The reported results illustrate the application of finite element (FE) based and SSF-based solutions of the PE for one of the most difficult to treat propagation mechanisms, yet of great significance for the performance of radars and communications links working in coastal and maritime zones — the tropospheric ducting mechanism. Recent achievements, some unresolved issues and ongoing developments related to further improvements of the PE method application to the propagation channel modeling in sea environment are highlighted.

Modeling of Diffraction Coupling in Radio Propagation Inside Tunnel Environments

2016 ◽  
Author(s):  
Arash Aziminejad ◽  
Andrew W. Lee ◽  
Gabriel Epelbaum
Keyword(s):  
Mode Conversion ◽  
Data Communication ◽  
Radio Propagation ◽  
Radio Communication ◽  
Data Link ◽  
Radio Communications ◽  
Propagation Modeling ◽  
Sharp Edges ◽  
Reliable Solution ◽  
Almost All

The overall performance of a Communication-Based Train Control (CBTC) system largely depends on the performance of its Data Communication Subsystem (DCS). The DCS network in almost all CBTC commercial system products marketed in the last decade utilizes radio communications in the open ISM bands (2.4 GHz or 5.8 GHz) to establish the bi-directional data link between the central/wayside and onboard segments. To ensure a stable and sound radio communication, a key question is the number of the wayside Access Points (APs) and locations of their antennas. Radio propagation modeling aims to provide an optimal and reasonably reliable solution to the cited question. The diffraction impact of sharp corners and edges in tunnels on the radio propagation process, however, has not been accounted for in majority of models. The purpose of the present research is to incorporate the effect of diffraction coupling due to sharp edges in tunnel sections which include geometrical discontinuities such as cross-junctions and L-bends through ray-mode conversion. The proposed modeling approach offers sufficient versatility to assimilate a variety of discontinuous geometries involving sharp edges in a tunnel environment. Numerical and empirical results suggest that the model provides an accurate tool for analyzing diffraction effects of tunnel discontinuities with sharp edges on the process of radio propagation.

scholarly journals Seamless Guidance System Combining GPS, BLE Beacon, and NFC Technologies

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Rung-Shiang Cheng ◽  
Wei-Jun Hong ◽  
Jheng-Syun Wang ◽  
Kawuu W. Lin
Keyword(s):  
Global Positioning System ◽  
Near Field ◽  
Smart Phone ◽  
Location Based Services ◽  
Guidance System ◽  
Campus Environment ◽  
Accurate Localization ◽  
Global Positioning ◽  
Graphic Information ◽  
Outdoor Environments

Users rely increasingly on Location-Based Services (LBS) and automated navigation/guidance systems nowadays. However, while such services are easily implemented in outdoor environments using Global Positioning System (GPS) technology, a requirement still exists for accurate localization and guidance schemes in indoor settings. Accordingly, the present study proposes a system based on GPS, Bluetooth Low Energy (BLE) beacons, and Near Field Communication (NFC) technology. Through establishing graphic information and the design of algorithm, this study develops a guidance system for indoors and outdoors on smart phones, wishing to give user perfect smart life through this system. The proposed system is implemented on a smart phone and evaluated on a student campus environment. The experimental results confirm the ability of the proposed app to switch automatically from an outdoor mode to an indoor mode and to guide the user to requested target destination via the shortest possible route.

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