Research On Propagation Characteristics Of Radio Wave In Outdoor Microcell By Ray-Tracing

Radio propagation prediction is an important link of the wireless network in planning and design, with the rapid development of mobile communications and the shortage of spectrum resources,so the coverage area of micro cellular city is becoming more and more small, which makes the area of statistical similarity can not be universal,the experience model of radio wave propagation can not be accuracy,at this time we need to establish an efficient and accurate algorithm to analyze the characteristics of wave propagation in the cells. Ray tracing algorithm is an efficient algorithm for the analysis of the wireless channel characteristics, it is based on the image theory, the geometrical theory of diffraction(GTD), the uniform theory of diffraction(UTD) for the prediction of the electric field intensity. Whether it is The forward algorithm or reverse ray tracing algorithm, The reliability and efficiency of the algorithm has been the research focus.This thesis is based on ray tracing method of a virtual source tree An effective ray tracing method for prediction of outdoor radio propagation was presented in this thesis Using the database to establish the position of environment information, find out all rays from source to receiving point, by the storage structure of the multi tree in data structure to establish a virtual source tree, postorder traversal of the tree to find out all propagation paths from a transmitter to a receiver for calculation. The algorithm is accelerated by accelerated technology(back acquisition and judge occlusion). This algorithm is based on the image method, which is a reverse ray tracing algorithm and combined the forward algorithm ideas so it has high computational efficiency. This thesis used Matlab as the development platform to realize the algorithm. The path loss is calculated by geometrical optics and UTD. The simulation results verify the effectiveness of this algorithm. Finally,this thesis analyzed the radio wave propagation characteristics in the different city environment model.