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In this paper, an overview of the overall channel characterizations for wireless communication systems in underground mines is presented. Such environments, because of the very nature of the mining operation, the complexity of the systems, and the procedures and extraction methods of the minerals are considered to be dangerous, hazardous and aggressive. Radio signals suffer from strong attenuations...
The Owl Positioning System (OwlPS) was originally designed as a general-purpose Wi-Fi-based indoor positioning system. It is also a tool to compare several positioning techniques from the same input data, and was used for this purpose in previous work. In this work, OwlPS is adapted to a very specific “indoor” environment, namely underground mine tunnels, which brings its own problematics in terms...
An efficient time domain technique on the basis of numerical inversion of Laplace transform and Prony's method is extended to the transient analysis of ultra wideband pulses transmitting through a lossy dielectric slab. The results obtained using this technique agree with those obtained using the FDTD technique, and are consistent with those published in the literature. Furthermore, the corresponding...
The preceding work is extended to the analysis of the pulse reflected from a lossy interface with an incident angle not smaller than the Brewster angle. The comparison between our results for vertical polarization and the published ones is made and a good agreement is shown. The variation trends of the shapes of reflected pulses with an incident angle are presented and discussed both for horizontal...
In terms of network parameters defined at the input terminals, expressions applicable to any array configuration are derived for the S/N ratio. The formulation is made in such a way that it becomes possible to account for coupling effects that arise from the geometry of the array and the current distributions on the elements of the array. Since the S/N ratio consists of the ratio of two Hermitians...
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