基于三维反向射线跟踪的电波传播预测

Radio Wave Propagation Prediction Based on 3D Reverse Ray-tracing

在复杂城市传播环境中,搜索三阶及以上反射及绕射路径能提高电波损耗预测精度,但现有研究主要针对二阶及以下反射及绕射路径。为此,提出一种任意阶反射及绕射反向射线跟踪算法。该算法基于镜像原理和一致性绕射理论,反向搜索确定射线传播路径,同时通过正向筛选过程建立可见多边形、棱边和场点,从而减少相交测试次数,降低高阶路径的搜索复杂度。在此基础上论述反射及绕射次数等因素对电波传播预测精度和复杂度的影响。数值仿真结果表明,考虑高阶传播路径能有效提高预测精度和预测效率,为三维城市中电信基站的规划设计和网络优化提供依据。

In traditional reverse ray-tracing and predicting model, the order of reflection and diffraction is two or less. In this paper, a new 3D reverse ray-tracing algorithm for accurate field strength prediction is proposed, particularly suitable for urban scenarios. The orders of refection and diffraction are arbitrary. Virtual source tree is created by directing search, and after that all valid paths from transmitter to receiver can be found quickly by inversing search. The effects of order of reflection and diffraction on predicting precision and complexity are also analyzed. Numerical results of the simulation show that this algorithm has higher accuracy and efficiency, which is quite useful for the design and optimization of wireless network.