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Ítem Heuristic UTD coefficients applied for the channel characterization in an andean scenario(Institute of Electrical and Electronics Engineers Inc., 2015-07-19) Navarro Cadavid, AndresThis paper presents a comparison of three heuristic coefficients for the Uniform Theory of Diffraction (UTD), used to characterize the radiowave scattering in typical urban scenarios. The coefficients were implemented in a propagation model based on 3D ray-tracing techniques in an andean scenario. In order to evaluate each coefficient we analyze the statistical behavior of the mean and standard deviation of the absolute errors between the estimated values and the measured data of path loss in a large number of receptor points. Finally, we show the path loss prediction for each heuristic UTD coefficients proposed.Ítem Delay spread control hiding first hit objects(2013-01-01) Navarro Cadavid, AndresThis paper proposes a methodology for the prediction and eventual cancellation of the main scatterer effects on broadcast radio channels. We assume the possibility of using absorbing material or paint to reduce the reflectivity of some surfaces and virtually 'hide' the scatterer, so as to control the maximum Delay Spread in terrestrial Digital Video Broadcasting systems. A desirable condition for the DVB-T2 operators is to limit the Delay Spread of radio channel in conditions where it is not possible to change the location or the orientation of the transmitting antenna; moreover, this can be useful to limit the Inter-Symbol Interference (ISI) and to improve the balance between the interleaving time and the channel capacity. In order to prove the applicability of object hiding, we used ray-tracing 3D techniques to identify the objects that can be hidden or camouflaged, and calculating the effect of objects on parameters of the DVB channel, in this case the delay spread. The results of the simulation applying physical hiding of object shown a expected reduction of Delay Spread. © 2013 EurAAP.Ítem Comparison of heuristic UTD coefficients in an outdoor scenario(Institute of Electrical and Electronics Engineers Inc., 2013-05-15) Rego, Cassio G.This paper presents a comparison of three heuristic coefficients for the Uniform Theory of Diffraction (UTD), used to characterize the radiowave scattering in typical urban scenarios. The coefficients were implemented in a propagation model based on 3D ray-tracing techniques for a Digital Video Broadcasting (DVB) service. In order to evaluate each coefficient we analyze the statistical behavior of the mean and standard deviation of the absolute errors between the estimated values and the measured data of path loss in a large number of receptor points in an outdoor scenario.Ítem Heuristic UTD coefficients for radiowave coverage prediction in a urban scenario(IEEE, 2015-11-03) Tami, DiegoThis paper presents a comparison of three heuristic coefficients for the Uniform Theory of Diffraction (UTD), used to characterize the radiowave scattering in typical urban scenarios. The coefficients were implemented in a propagation model based on ray-tracing techniques based in image theory. In order to evaluate each coefficient we analyze the statistical behavior of the mean and standard deviation of the absolute errors between the estimated values and the measured data of path loss in a large number of receptor points provided in the literature. Finally, we show the path loss prediction for each UTD coefficients proposed.