A ray-tracing approach for indoor/outdoor propagation through window structures

A ray-tracing approach for indoor/outdoor propagation through windows is proposed. Using both the finite-difference time-domain (FDTD) method and a ray-tracing algorithm, several cases of indoor/outdoor propagation through windows were investigated. It is shown that wave transmission through windows cannot generally be accounted for through a single transmission coefficient parameter. Instead, a full diffraction pattern needs to be accounted for and multiple-ray representation is therefore required. It is also shown that a single window model may be used to calculate transmission through set of windows in a typical building structure as a building block. Results from the implementation of a multiple-ray representation and FDTD simulations showed good agreement. Results were validated for both normal and oblique incident cases. The developed ray-tracing approach, therefore, facilitates the use of the developed window model in available ray-tracing algorithms often used for propagation characterization of urban environments. Simulation results were further validated by conducting measurements on scaled models at 30 GHz. The experimental results agreed well with the simulation data, thus validating the accuracy of the developed ray-tracing model for transmission through windows.