Prediction of indoor radio propagation with the ray splitting model including edge diffraction and rough surfaces

The installation of wireless indoor communication systems for business and private applications with high traffic densities demands site-specific information of suitable transmitter locations. The asymptotic computation of the indoor radio channel using ray tracing models is widely used, and usually considers rays reflected on and transmitted through walls and obstacles, as well as antenna characteristics. However, inclusion of edge diffraction and diffuse scattering on rough surfaces is a time consuming computational task and therefore usually neglected. Though it is unrealistic to describe indoor geometry in all details, in a surrounding of the receiver it is useful to consider essential scattering sources, e.g. wall edges. We describe a fast search algorithm for the ray splitting model that performs a simplified inclusion of edge diffraction and diffuse scattering at rough walls. Scattering sources of non-specular reflection are approximated by new radiation sources. A comparison of the predicted and measured values of the path loss in line-of-sight and non-line-of-sight situations within an office building demonstrates the capability of the algorithm