Ray Tracing In Multi-Floor Scenarios And Impact Of Buildings Geometric Modeling To Ray Tracing Prediction Result

Wireless data traffic is continuously increasing worldwide. More and more wireless communication processes occur in the outdoor microcell and indoor Picocell scenarios. Radio propagation channel is very important to determine the performance of a wireless communication system. Ray tracing technique is very suitable for these site-specific channels. This technique is a typical method for obtaining channel information based on actual geometrical layouts. In the ray tracing algorithm, the propagation of wave is predicted by geometrical optics and assumptions from the uniform theory of diffraction. Signal characteristics are calculated by electromagnetic theories. These two theories have inherent high-frequency limitation when applied to microwave frequencies. Moreover, degradation of the accuracy of simulation results by the geometric error should be resolved. In this paper, ray tracing algorithm in multi-floor scenarios is developed. The relation of prediction accuracy of ray tracing algorithm in the microcell scenario by the environment error is also studied.Related information on ray tracing model is initially introduced. Two basic theoretical foundations, namely, geometrical optics theory and the uniform theory of diffraction, are used. Calculation of reflected field, diffraction, and transmission field in the ray tracing algorithm is also presented. Furthermore, formulae of some important parameters, such as reception power and path loss, in wireless channel prediction are provided. Finally, a few related settings in the ray tracing implementation are described.Furthermore, this paper implements the ray-tracing algorithm for indoor multi-floor scenarios. Radio wave propagation simulation forecast has been performed in the multi-floor environment. Work in this issue can be divided as flow. All the ray paths are determined in two categories. Then electromagnetic field of each ray is established, and a four-floor multi-room scenario is created. Simulation was performed based on the ray tracing algorithm in the four floor multi-room scenario. In the beginning, transmitting and receiving antennae are placed on the same floor. We studied the radio wave coverage of line of sight area and shadow area. Then we examined the radio wave coverage of different floors.Moreover, the fourth chapter shows the influence of environment geometrical error on the path loss prediction of ray tracing algorithm. Because the simulation result of ray tracing algorithm is based on the environmental information of a particular scene, whether the geometrical information is precise or not is of great importance to the simulation result of ray tracing algorithm. In this paper, we obtain many error maps by artificially introducing geometric error into the original map. The error maps included multiple sets of maps in two types of errors. We could achieve many sets of results by simulating on the original and error maps using ray tracing algorithm. We observe the difference in the prediction results of ray tracing algorithm between different error types and error values compared with the path loss results of each tested point in all maps.Finally, this paper proposes the direction of future work. Future development primarily involves the improvement of prediction accuracy and acceleration of operational efficiency of ray tracing model.