Study On The Influence Of Environment Information On The Accurancy Of Ray Tracing Algorithm In Indoor Environment

The rapid development of mobile communication technology has driven the rapid growth of the market for wireless network equipment in indoor picocell environment. This makes it necessary to have an accurate propagation model to predict propagation channel characteristics in indoor environment. With the large-scale commercialization and rapid development of mobile communication technology in indoor environment, the traditional propagation models based on empirical and semi-empirical models cannot provide good predictions anymore because of their own limitations Time delay and angle of arrival information for multipath reception conditions can all be calculated by ray tracing technique, a kind of site-specific prediction method of predicting the radio channel characteristics of wireless communication systems. As a consequence, the ray tracing technology can provide the reliable theory basis for radio-wave propagation prediction and network planning.According to the feature of indoor picocell environment, a kind of format storage of geometric information and electrical parameters information is used to model indoor environment in this paper. On this basis, the ray tracing technique is used to predict the characteristic of radio channel in indoor environment. The influence of geometric information modeling error, electrical parameters modeling error and polarization of receiving antenna and transmitting antenna on prediction accuracy of ray tracing algorithm has been studied. The main contents and innovations are as follows:1. Two theoretical foundations of ray tracing are introduced at first: geometrical optics and uniform theory of diffraction. The computational formulas of the radio channel parameters that can be predicted by using ray tracing algorithm are described in detail. How to find the different kinds of ray-path is introduced in this paper and the operation procedure of using the three-dimensional ray tracing algorithm to predict the propagation channel characteristics is also described briefly.2. According to the feature of geometric information of indoor environment, two kinds of error maps are modeled. Based on the proposed error maps and the standard map, thereceived power and RMS delay spread is predicted along the line of sight route, non-line of sight route. The mean error and standard deviation between predictions by using errors maps and standard maps are presented and analyzed to find how the geometric information modeling errors influence prediction accuracy of ray tracing algorithm.3. According to the feature of electrical parameters information of indoor environment, the influence of relative permittivity modeling error and conductivity modeling error on prediction accuracy of ray tracing algorithm has been studied. Based on the error maps on which the electrical parameters of ceiling, floor, internal wall and indoor objects are modelled with different errors, the received power and RMS delay spread is predicted along the line of sight route, non-line of sight route. The mean error and standard deviation between predictions by using errors maps and standard maps are presented and analyzed to find how the electrical parameters information influence prediction accuracy of ray tracing algorithm4. The influence of polarization of receiving antenna and transmitting antenna on prediction accuracy of ray tracing algorithm has been studied in this paper. During the process of research, the receiving and transmitting antenna array surface is set aligned or not, and the receiving antenna is placed in the line of sight of transmitting antenna or not and two types of cross polarization and co-polarization are considered. As a consequence, the influence of polarization of receiving antenna and transmitting antenna on prediction accuracy of ray tracing algorithm has been studied in this paper.