Simplified ray-launching analysis for indoor propagation including multiple reflection effect inside walls

This paper proposes a simple accuracy improvement of the ray-launching analysis by efficiently including the multiple reflection effect inside lossy wall. The Green's function problem in the presence of a lossy dielectric slab, to derive the transmitted ray component with the internal multiple reflections is considered. Here, so as to realize the appropriate ray shooting inside lossy material, alternative real refraction angle is introduced, instead of the conventional complex refraction angle. The true angle presents easy execution of the ray-launching scheme in lossy material for precisely calculating the transmitted ray component. The validity of the improvement is finally confirmed by some numerical experiments for both small and large lossy walls' cases.