FDTD-Based Diffuse Scattering and Transmission Models for Ray-Tracing of Millimeter-Wave Communication Systems

TL;DR

This paper introduces a two-stage FDTD-based method to model diffuse scattering and transmission at millimeter-wave frequencies, improving the accuracy of ray-tracing in 5G indoor environments by accounting for surface roughness effects.

Contribution

It presents a novel combined approach using FDTD and ray-tracing to accurately model diffuse scattering from rough surfaces in millimeter-wave propagation.

Findings

Diffuse scattering significantly affects propagation at 28 GHz.

Surface roughness reduces reflected and transmitted wave magnitudes.

The method enables realistic indoor environment modeling for 5G systems.

Abstract

At millimeter-wave frequencies, diffuse scattering from rough surfaces is an important propagation mechanism. Including this mechanism in radio propagation modeling tools,such as ray-tracing, is a key step towards realizing accurate propagation models for 5G and beyond systems. We propose a two-stage solution to this problem. First, we model reflection and transmission through rough slabs, such as doors, walls and windows with the FDTD method. Our results indicate the influence of roughness and whether this influence is measurable, either reducing the magnitude of the reflected and transmitted waves, or (most importantly) generating diffuse scattering components. In the latter case, the surface effectively acts as a secondary source, whose pattern is computed by full-wave analysis. Then, this pattern is embedded in a ray-tracer, enabling the computation and tracing of diffuse scattering field components. We demonstrate this approach in the ray-tracing analysis of a 28 GHz indoor environment.