Calibrated Broadband Ray Tracing for the Simulation of Wave Propagation in mm and Sub-mm Wave Indoor Communication Channels

Due to the extremely high bandwidths of mm and sub-mm wave communication systems, conventional ray tracing can only be applied limitedly to simulate the wave propagation behavior in indoor environments. In this paper, a broadband ray tracing approach is presented that takes into account the propagation conditions at multiple frequency points within the simulated band instead of one discrete frequency only. The simulation of channels in the time as well as in the frequency domain are considered. Additionally, the impact of the Fourier transformation on the shapes of the power delay profiles and on the temporal channel characteristics is investigated. Moreover, a novel broadband calibration approach is introduced that utilizes not only the temporal, but also the spatial channel information, namely angle of arrival and angle of departure. Performance and accuracy of the calibration algorithm are demonstrated using the example of channel measurements recorded in an indoor environment at 300 GHz. A significant accuracy improvement of the ray tracing simulations is achieved.