3.5 GHz频段城市环境路径损耗特性研究

应用一种基于入射和反弹射线法(shooting-and-bouncing ray, SBR)以及一致性绕射理论(uniform theory of diffraction，UTD)的射线跟踪方法,主要研究了在3.5 GHz频段上发射天线的高度、位置等对城市环境中路径损耗特性的影响。应用SBR实现从发射天线到接收点的射线查找,然后应用UTD计算与每条射线相关的复电场，研究发现，在3.5 GHz频段上，路径损耗特性对发射天线的高度不敏感,而在这一频段改变发射天线的位置会引起路径损耗特性产生很大的改变。对实测值和仿真值进行了比较,比较显示实测值和仿真值吻合得较好,这说明应用基于SBR/UTD的射线跟踪法可以有效预测城市环境中的路径损耗特性。

Research on path loss at 3.5 GHz in urban environments

Using a ray-tracing method based on shooting-and-bouncing ray(SBR)/uniform theory of diffraction(UTD), this paper mainly analyzed how the transmitter height and transmitter location influenced the path loss respectively. Firstly SBR was used to find the propagation paths to each receiver point, and then UTD was used to evaluate the complex electric field associated with each ray path. It is shown that path loss is not very sensitive to transmitter height, and the location of transmitter affects the propagation characteristics extraordinarily. Finally, the results between the forecasts and measurements are presented. And the predicted results are in good agreement with the measured one, which shows that this kind of ray tracing method can efficiently predict the propagation characteristics.