城市微蜂窝环境下一种改进的射线跟踪预测模型

针对射线跟踪模型中建立虚拟源树效率不高的问题，基于构建一种左儿子右兄弟结构的新型虚拟源树，提出了一种改进的准三维射线跟踪模型．该模型通过有效的反射预处理技术来快速地确定反射源的所有可见面，并结合改进的极面扫描方法，避免了不必要的重复判断和相交测试．仿真结果表明，提出的射线跟踪模型是高效的，并能为微小区环境下的无线电波传播预测和网络规划提供可靠的理论依据．

Improved ray tracing prediction model in urban microcellular environments

The traditional ray tracing model usually has a disadvantage of low efficiency in creating a virtual source tree. In this paper, an improved quasi three-dimensional ray tracing model based on creating a new virtual source tree in which the relationship between neighbor nodes is a left-son-and-right-brother one is presented. In the model, a preprocessing technique for the reflection is used in order to accelerate the calculation of visible faces of the reflection source. Furthermore, the avoidance of unnecessary overlapping and intersection tests is achieved by using an improved polar sweep algorithm. Simulation results demonstrate that the proposed model is efficient and can provide the reliable theoretical basis for radio-wave propagation prediction and network planning in urban microcellular environments.