AN ADAPTIVE SUBDIVISION OF BEAMS FOR POLYGONAL OBJECTS IN VISUAL SIMULATION OF HIGH FREQUENCY ELECTROMAGNETIC WAVE PROPAGATION

摘要

For providers and customers of wireless communication systems using high frequency electromagnetic wave such as wireless LAN and cellular phone, it is important to know an electromagnetic wave propagation situation. Therefore, a representation method of the propagation situation in urban space is necessary, which can show at least summary of coverage, reliability and leakage through showing the propagation situation according to configurations and instructions of a user. We have proposed an interactive system with a three dimensional map data, which can calculate and show the propagation situation. In the proposed method, combining a beam tracing method with adaptive subdivision with three dimensional GIS (Geographic Information System), we can analyze and visualize a propagation situation. However, since the proposed method can be applied to three dimensional map data composed by a set of triangular meshes, the method is not so efficient for buildings and roads, which are usually defined as polygons. Therefore in this paper, we propose an improved method, which can handle polygons directly. The proposed method can benefit reduction of number of both of objects to be checked in the beam tracing and the adaptive subdivision.