Modeling And Simulation Of Indoor Signal Channel Based On Ray Tracing

In recent years, with the popularity of mobile networks and handheld devices,geographical information with spatial position characteristics is playing a more and more important role in all areas of daily life, resource management and socio-economic activities. As the "last kilometer" of the positioning technology,indoor positioning technology emerges, which integrates base station positioning, wireless communica-tions, inertial navigation, and other technologies to solve the positioning problem in the indoor environment. But the indoor environment is more complicated than the outdoor environment, and the indoor location accuracy requirements are more stringent than the outdoor positioning, resulting in that traditional channel model is no longer useful, thus it’s a more serious challenge for the propagation analysis of positioning signal.Therefore, an indoor signal channel model based on ray tracing is designed and implemented, which aims to enhance the indoor propagation analysis accuracy. The main work is as follows:First of all, considering the issues that statistical model cannot support a specific scene, which is influenced by the environment and does not have a high prediction accuracy, an indoor signal channel model based on ray tracing is constructs. The model uses industry indoor maps norm, named as COLLADA data format, extracts space key information, and then takes advantage of ray tracing technology to simulation and analysis the ray propagation path in the indoor scenes to obtain the channel parameters.At last, ray propagation paths are displayed in the indoor scenes. The proposed model cut down the cost of storage of the indoor maps, reduces the overhead cost of the extraction of the space key information, which is ensured the accuracy of the indoor propagation analysis.Secondly, considering the issues that the high computational complexity and computational cost of ray tracing technology, the amount of computation, analyze the propagation path and intersection testing are taken into account, proposing two ray tracing acceleration algorithm. It reduces the overhead cost of ray propagation paths analysis by using a lightweight visual surface judgement algorithm, and raises the efficiency of ray tracing algorithm by using historical data, thereby reducing the cost of computing resources and the running time of propagation analysis.Finally, the indoor signal propagation analysis system based on ray tracing is implemented. It restores the original scene by modeling, and extracts key parameters of the scene which will be compared to verify the feasibility and effectiveness of extraction algorithm. This system verifies the result of propagation analysis by simulating several ray propagations in the indoor scene, combined with numerous comparative experiments in the same condition to demonstrate the effectiveness of the ray tracing accelerated algorithms.