A Multiple Huygens Surface-Based Ray Tracing Framework with GPU Acceleration

A ray tracing framework based on the utilization of multiple Huygens surfaces is introduced and evaluated. As such, complex propagation environments are divided into smaller subdomains, thereby confining the rays to propagate in a smaller and simpler space. The subdomains are surrounded by the Huygens surfaces and equivalent Huygens sources interconnect the ray-based field representations in neighboring subdomains. Compared to conventional shooting and bouncing rays (SBR)-based ray tracing simulations, which detect relevant ray hits at receivers via small reception spheres, this approach distributes the wave representation over many rays and collects their overall influence via Huygens surface integrations. By a smart choice of the Huygens surfaces, the ray coverage in complex environments can be increased considerably. Concerning diffraction computations, which rely conventionally on the uniform theory of diffraction (UTD), the flexibility of choosing Huygens surfaces allows to distribute diffraction edges over different subdomains, thus, eliminating the need for consecutive UTD evaluations and the corresponding problems in finding correct multiple diffraction paths. Together with smart ray launching strategies and quickly converging integration methods, the presented approach allows many successive diffraction evaluations with reasonable accuracy and efficiency. The implementation is based on graphics processing units (GPUs), enabling massively parallelized simulations.