Study On The Prediction Of Indoor Radio Wave Propagation Based On Ray Tracing Technique

With the development of mobile communication, the demand for indoor coverage becomes higher and higher. Indoor field prediction has been one of basic issues for wireless network planning. Therefore, the accurate and time-saving technique for radio waves propagation prediction has the important meaning for network planning and optimization in indoor environment. This paper mainly deals with the ray tracing technique on predicting the characteristics of indoor wave propagation. The main works are as follows:1) The existing prediction models and methods are summarized, and the necessity of indoor network prediction is present by using the method of ray tracing. The feature of indoor radio waves propagation is analyzed and the rationality is pointed out using ray tracing technique for indoor radio waves propagation prediction.2) The influence of diffusion from indoor rough walls and a few objects with small scale in radio waves propagation is investigated. The definition and the classification of small scale diffusion is introduced, and the influence of small scale diffusion on ray tracing model is analyzed; The mirror reflection coefficient is modified, and the diffuse ray distribution of (virtual) source’s visible rough surface is studied, with association of Gaussian rough surface polarization scattering coefficient and electromagnetic scattering energy distribution. The diffuse coefficient of specific frequency and rough wall is calculated and the influence of diffuse rays of indoor rough wall on ray tracing model prediction results is discussed.3) According to the idea of virtual source ray tracing, the virtual source tree structure of indoor wave effective paths is built, and then the indoor ray tracing prediction procedure is completed.4) Based on the ray tracing algorithm, with Visual Studio2010platform for design, the indoor3D ray tracing prediction software has been developed using the C#, C and Matlab mix technique. Finally, the radio waves propagation characteristics inside the typical indoor scene are studied using the software.