Dinael Guevara

DVB Coverage Prediction Using Game Engine Based Ray-Tracing Techniques

This paper presents the results of an evaluation of a propagation model based on ray-tracing techniques using a game engine and Graphics Processing Unit (GPU) in outdoor scenarios, as a gap-filler for a Digital Video Broadcasting Handheld (DVB-H) service. This model involves complete identification of the parameters of wave propagation, multipath components between the transmitter and the receiver as attenuation, time delay of arrival (TDA), full polarimetric transmission matrix, direction of arrival DoA and the direction of departure DoD. In the paper, we present the results of the simulation and compare them with measurements, obtaining a satisfactory fit.

Applicability of Game Engine for Ray Tracing Techniques in a Complex Urban Environment

This work presents results for a new method of ray tracing in urban environments using game engine and graphic processing unit (GPU). First advantage obtained with this method is the simplicity for 3D modeling from raster digital elevation model (DEM). Second advantage is the ability to precisely obtain ray parameters and the multiple paths interacting between transmitter and receiver in urban environment for high and low base station. A third advantage is the reduction in computing time by using the GPU capacity. In this paper, we show simulation results and compare them with measurements, obtaining a good fit.

Measurement-based ray-tracing models calibration in urban environments

This paper investigates the effect produced on the accuracy of the estimate of path loss in an outdoor environment in order to adjust the permittivity values for building wall, building roof and street floor by using a full 3D ray-tracing system. Due to the complexity of a real situation, estimation of path loss using the ray-tracing method is generally assumed one or three large classes of homogeneous materials to represent the building walls, building roofs and street floors in order have a viable model of the 3D environment. However, in a real case, an outdoor environment consists of many buildings and streets made of heterogeneous materials. We analyze the behavior of the statistical variation of standard deviation, correlation coefficient and the average error between the values of estimated and measured path loss data when considering various values of permittivity of these three classes. Finally we adjust the values of permittivity obtaining a reasonable improvement of ray tracing to estimate the path-loss.

Game engines ray-tracing models for indoor channel modeling

This paper investigates the use of a full 3D ray-tracing system based on Game Engine for the prediction of channel parameters in indoor using frequencies lower than usual. We explore the modeling of indoor channel for Digital TV frequencies and analyze the behavior of material on such low frequencies and how the frequencies affect the constitutive parameters of materials in the scenario. Because of the environment used for experimentation, the number of rays is very high and the number of interactions is higher than usual. We show results of the ray tracing model compared with measurements of delay spread at 594MHz.

Using 3D game engines and GPU for ray launching based channel modeling in indoor

This paper investigates the use of a full 3D ray-launching system based on Game Engine and GPU for the prediction of channel parameters in indoor. We explore the behavior of the materials and the possible influence of objects external to the room where measurements were performed. We explore the modeling of indoor channel for Digital TV frequencies and analyze the behavior of material on such low frequencies and how the frequencies affect the constitutive parameters of materials in the scenario. Because of the environment used for experimentation, the number of rays is very high and the number of interactions is higher than usual. We show results of the ray tracing model compared with measurements of delay spread at 594MHz in a meeting room.

Indoor Propagation Using a Game Engine Ray-Based Model in Indoor Scenario at 5.4GHz

The results of a simulation of signal propagation strength in indoor environment using a game engine ray-based tool and use of an open source 3D modeling tool for scenario building are presented in this paper, showing the flexibility of the XML description language for this kind of scenario. We show simulation results and compare them with an extensive set of measurements for an indoor scenario with multiple materials in the 5.4GHz band, obtaining a good match between the ray-based tool and measurements of received power. We found also that constitutive parameters have an important effect on the simulation results and made some small adjustments to improve results.

Heuristic UTD coefficients applied for the channel characterization in an andean scenario

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 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.

Analysis of Heuristic Uniform Theory of Diffraction Coefficients for Electromagnetic Scattering Prediction

We discuss three sets of heuristic coefficients used in uniform theory of diffraction (UTD) to characterize the electromagnetic scattering in realistic urban scenarios and canonical examples of diffraction by lossy conducting wedges using the three sets of heuristic coefficients and the Malyuzhinets solution as reference model. We compare not only the results of the canonical models but also their implementation in real outdoor scenarios. To predict the coverage of mobile networks, we used propagation models for outdoor environments by using a 3D ray-tracing model based on a brute-force algorithm for ray launching and a propagation model based on image theory. To evaluate each set of coefficients, we analyzed the mean and standard deviation of the absolute error between estimates and measured data in Ottawa, Canada; Valencia, Spain; and Cali, Colombia. Finally, we discuss the path loss prediction for each set of heuristic UTD coefficients in outdoor environment, as well as the comparison with the canonical results.

Measurement-based ray-tracing models calibration of the permittivity and conductivity in indoor environments

espanolEn este trabajo se muestran los resultados de una herramienta de lanzado de rayos para estimacion de parametros de canal en un escenario de interiores (Indoor) y se comparan sus resultados con mediciones realizadas con un sistema DVB-T, utilizando un equipo analizador vectorial de redes, con el que se mide el Root Mean Square Delay Spread (RMS-DS), a partir del parametro S12. Para las mediciones se utiliza un transmisor con potencia de 10mW y se toman los valores medios de RMS-DS en 39 puntos de medida dis-tribuidos alrededor del escenario. Se muestra tambien el ajuste empirico necesario realizado a los parametros constitutivos del escenario, con el fin de mejorar los resultados en el Delay Spread. Se muestra en el articulo que este tipo de herramientas basadas en rayos son sensibles al numero de interacciones consideradas en el modelo asi como a los parametros constitutivos de los materiales del escenario. Dadas las bajas frecuencias utilizadas en este trabajo, tambien se encuentra que algunos elementos externos al escenario pueden influir en los resultados y deben ser considerados en las simulaciones en interiores (Indoor). EnglishIn this paper, we show the results of a ray launching tool for channel estimation in indoor scenario and compare it with measurements in a DVB-T system, using a Vector Network Analyzer used to obtain the Root Mean Square Delay Spread (RMS-DS), obtained from S12 parameter. We use a 10mW transmitter and make measurements in 39 different points in the scenario. Also we show the empirical adjustments made in the constitutive parameters, in order to improve the Delay Spread results. We show that this kind of ray based tools are very sensitive to the number of interactions considered in the model and also to the values of the constitutive parameters of the different elements in the scenario. For the low frequencies used for this work, we found also that some external elements can influence the results and must be considered for indoor simulations.

Delay spread estimation in 4,2GHz band using game ray based method

The evolution of mobile systems has leaded to new frequency attributions like 3.5 to 4.2 GHz band. In this paper, we show the channel behavior of 4.2GHz in indoor scenario using a ray based system and compare delay spread results with measurements. We try to tune our model, adjusting permittivity values to reduce the mean standard error and analyze the effect of the permittivity differences in the scenario.