Zhou Chenming
Office of Mine Safety and Health Research, National Institute for Occupational Safety and Health, Pittsburgh, PA 15236 USA.
IEEE Trans Antennas Propag. 2017 May;65(5):2624-2634. doi: 10.1109/TAP.2017.2677398.
At the ultrahigh frequencies common to portable radios, tunnels such as mine entries are often modeled by hollow dielectric waveguides. The roughness condition of the tunnel walls has an influence on radio propagation, and therefore should be taken into account when an accurate power prediction is needed. This paper investigates how wall roughness affects radio propagation in tunnels, and presents a unified ray tracing and modal method for modeling radio propagation in tunnels with rough walls. First, general analytical formulas for modeling the influence of the wall roughness are derived, based on the modal method and the ray tracing method, respectively. Second, the equivalence of the ray tracing and modal methods in the presence of wall roughnesses is mathematically proved, by showing that the ray tracing-based analytical formula can converge to the modal-based formula through the Poisson summation formula. The derivation and findings are verified by simulation results based on ray tracing and modal methods.
在便携式无线电常用的超高频下，诸如矿井入口之类的隧道通常由中空介质波导建模。隧道壁的粗糙度条件会对无线电传播产生影响，因此在需要进行精确功率预测时应予以考虑。本文研究了壁面粗糙度如何影响隧道中的无线电传播，并提出了一种统一的射线追踪和模式方法，用于对具有粗糙壁面的隧道中的无线电传播进行建模。首先，分别基于模式方法和射线追踪方法，推导了用于模拟壁面粗糙度影响的一般解析公式。其次，通过证明基于射线追踪的解析公式可以通过泊松求和公式收敛到基于模式的公式，从数学上证明了在存在壁面粗糙度的情况下射线追踪和模式方法的等效性。基于射线追踪和模式方法的仿真结果验证了推导过程和研究结果。
