Journal ArticleDOI
A ray model for decimetric radiowave propagation in an urban area
J.-P. Rossi,A. J. Levy +1 more
TLDR
In this article, a ray-tracing model involving multiple reflections and diffractions is proposed to predict wideband decimetric radio wave propagation in an urban area, in which only buildings close to the vehicle are considered.Abstract:
A ray-tracing model involving multiple reflections and diffractions is proposed to predict wideband decimetric radio wave propagation in an urban area. A computer code was developed in which only buildings close to the vehicle are considered. Wall irregularities and electromagnetic properties of material are taken into account by a constant reflection factor, while diffraction attenuation is computed from geometrical theory of diffraction results. Simulated channel path losses and complex impulse responses are compared with some measurements performed in Paris at a 900-MHz central frequency.read more
Citations
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Journal ArticleDOI
Overview of spatial channel models for antenna array communication systems
TL;DR: This tutorial reviews the key concepts in spatial channel modeling and presents emerging approaches, and reviews the research issues in developing and using spatial channel models for adaptive antennas.
Journal ArticleDOI
Site-specific propagation prediction for wireless in-building personal communication system design
TL;DR: Time delay comparison shows that the amplitudes of many significant multipath components are accurately predicted by this model, and the effective building material properties are derived for two dissimilar buildings based upon comparison of measured and predicted power delay profiles.
Journal ArticleDOI
UHF propagation prediction for wireless personal communications
TL;DR: The paper starts by reviewing the characteristic signal variations observed in CMR systems employing high base station antennas to cover macrocells having radius out to 20 km, and discusses advances in site specific prediction for outdoor and indoor propagation.
Journal ArticleDOI
A mixed ray launching/tracing method for full 3-D UHF propagation modeling and comparison with wide-band measurements
J.-P. Rossi,Y. Gabillet +1 more
TL;DR: In this paper, a geometrical ray implementation for mobile propagation modeling (GRIMM) is presented, which splits the 3D ray construction problem into two successive two-dimensional (2-D) stages without loss of generality compared with brute-force 3-D ray methods.
Journal ArticleDOI
Antenna Effects on Indoor Obstructed Wireless Channels and a Deterministic Image-Based Wide-Band Propagation Model for In-Building Personal Communication Systems
TL;DR: The results show that linearly polarized (LP) directional antennas are more effective in combating multipath components than other types of antennas in OBS channels.
References
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Journal ArticleDOI
Geometrical Theory of Diffraction
TL;DR: The mathematical justification of the theory on the basis of electromagnetic theory is described, and the applicability of this theory, or a modification of it, to other branches of physics is explained.
Journal ArticleDOI
Empirical formula for propagation loss in land mobile radio services
TL;DR: An empirical formula for propagation loss is derived from Okumura's report in order to put his propagation prediction method to computational use.
Journal ArticleDOI
A uniform geometrical theory of diffraction for an edge in a perfectly conducting surface
R.G. Kouyoumjian,P.H. Pathak +1 more
TL;DR: In this article, a compact dyadic diffraction coefficient for electromagnetic waves obliquely incident on a curved edse formed by perfectly conducting curved plane surfaces is obtained, which is based on Keller's method of the canonical problem, which in this case is the perfectly conducting wedge illuminated by cylindrical, conical, and spherical waves.
Journal ArticleDOI
A theoretical model of UHF propagation in urban environments
J. Walfisch,Henry L. Bertoni +1 more
TL;DR: In this paper, the authors developed a model in which the rows or blocks of buildings are viewed as diffracting cylinders lying on the earth, and the propagation process reduces to multiple forward diffraction past a series of screens.