An efficient 2-D MLFMM-UTD hybrid method to model non-line-of-sight propagation

We present a hybrid method that combines the Multilevel Fast Multipole Method (MLFMM) with the Uniform Theory of Diffraction (UTD) to model two-dimensional (2-D) scattering problems. The method is especially suited to model scattering in the presence of very large scatterers that obstruct the line-of-sight propagation between different devices with a more intricate geometry, such as antennas. The discretization of the large scatterers is avoided by using ray-based methods. An O(n) scaling is achieved for the computational time and required memory, n being the number of unknowns needed to discretize the antennas. The method is validated by a numerical example.