Modelling complex objects within ray tracing simulations applied to beyond 5G communications

Details

Supervisors

Oestges, Claude

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil électricien, à finalité spécialisée

Abstract

Over the years, engineers have consistently tackled the challenge of satisfying the ever-growing demand for faster wireless data transfer rates and lower latency. One approach to achieve this, is to operate at higher frequencies; however, this introduces new challenges, due to higher frequency signals' increased susceptibility to interference from minor environmental elements. In turn, this increases the difficulty of channel modelling, which provides crucial information required by engineers to design their systems adequately. Traditionally, engineers relied on costly and time-consuming measurement campaigns, or empirical models derived from extensive channel measurements, to gain insight into channel characteristics. However, at higher frequencies these empirical models often fail to capture the complexity of specific environments, due to the increasing influence of minor environmental details. To address these concerns, ray tracers have been developed and are, in theory, able to provide channel characteristics as accurate as the model of the environment fed to them. In this thesis, a ray tracer is developed (openly available at https://github.com/MaximeLeu/RayTracing.git) and validated against real world measurements at 12.5 GHz and 30 GHz. Our ray tracer uses an innovative pathfinding technique, min path tracing, which seamlessly handles diffraction and curved geometries. The fields propagated by the rays are computed using Geometrical Optics and the Uniform Theory of Diffraction. The functionality of the ray tracer is showcased through an analysis of the channel characteristics of Place de La Vieille Halle aux Blés in Brussels, at 12.5 GHz, under two different transmitting antenna placements: at street level, or atop a building. Our findings suggest that placing the transmitting antenna at street level would lead to a much lower temporal dispersion of the channel. Additionally, we observed that spatial channel dispersion in the elevation plane is also substantially lower at street level. Overall, the lower channel dispersion achieved by street level antennas would facilitate higher potential wireless data transfer speeds, compared to antennas mounted atop buildings.