A Novel Ray-Tracing Algorithm for Non-Specular Diffuse Scattered Rays at Terahertz Frequencies

This paper presents a novel self-programmed three-dimensional (3D) ray-tracing algorithm (RTA) based on Beckmann-Kirchhoff (B-K) model for modeling diffuse scattering mechanism in non-specular directions at terahertz (THz) frequencies. The terahertz or submillimeter-wave frequencies pose unique challenges for channel modeling due to sparse and extreme frequency selective behaviour of the propagation mechanism. In particular, the most critical feature proved to provide important contributions in determining spatial and temporal dispersion in the submillimeter-wave band is the diffuse scattering mechanism, wherein an incident ray may split into a specular and several non-specular (diffused scattered) rays after bouncing off from rough materials. This makes the diffuse scattering or scattering from rough surfaces a necessary design consideration constituting a high proportion of all the propagation rays and hence, must be accounted for propagation modeling to accurately predict channel characteristics. Next, we integrate our MATLAB-based proposed algorithm to a commercial ray-tracing tool to derive a spatiotemporal model of scattered multipath propagation channels considering rough materials in a realistic office environment for both line-of-sight (LoS) and non-line-of-sight (NLoS) scenarios. So far none of the commercially available ray-tracing tools have implemented this scattering model yet.