Research And Implementation Of Ray-Tracing Algorithm

Base station’s location selection, construction and maintenance are the key aspect to ensure the quality of mobile communication system and it is an important content of network planning. Propagation model is a key factor to affect the base station planning.With the development of mobile communication, the demand of personal communication changes from low-speed data services such as the voice and data to high-speed data services such as the video. Therefore the coverage and transmission power of base stations become smaller, and the microcell and the picocell appear. Statistical similarity is not correct in small urban areas which have high density of population and building and macrocell model based on the measured data can not be used. The key of analyzing wave propagation model of microcell is the accurate radio prediction theory method. Ray tracing algorithm is an electromagnetic theory of high frequency approximation, combined with computer technology and graphics technology. It is also a theory that is used to analyze multipath effects of mobile communication and calculate of various transmission parameters based on modeling of high precise environment.An effective prediction model which is suitable for microcell wave environment is presented in this paper which is two dimensional ray tracing model based on the virtual sources. The algorithm uses a linked list to store the radiation sources with a class and two binary tree to store different classes of sources which routing information from the emission source to the receiving point. Such store structure is more efficient. Various acceleration technologies is used in the model. Geographic information processing includes processing the3D map information to two-dimensional information, and joined profile information in the building parameters which reduce the redundancy calculation in the back gathering and occlusion testing. For partial occlusion handling, a new method is used and the efficiency is improved. The Visual Studio2008platform and C++programming language is used to realize the model and verify the validity of the model. The algorithm is simple in theory and high precision. When compared with3D simulation algorithm, they have the same trend.