A 3-D integrated macro and microcellular propagation model, based on the use of photogrammetric terrain and building data

This paper describes a fully three-dimensional deterministic propagation model based on a radar cross-section analysis of terrain pixels and building walls. The model utilises a variable resolution terrain database as well as a buildings database to predict signal strength, time dispersion and fading information, in addition to providing spatial information (e.g. arrival angles) for the propagation channel. It considers scattering from illuminated terrain pixels and building walls as well as considering off-axis terrain and rooftop diffraction contributions. The model can be particularly useful for integrating macrocells and microcells e.g. predicting interference in a microcell due to a nearby macrocell or vice versa. Signal strength predictions from the model show good agreement with narrowband measurements for a rural macrocell. The effects of buildings and foliage in the propagation channel are investigated, and reveal that large errors can result if these effects are ignored. The accuracy improvement of the 3-D analysis over the simpler 2-D approach is also demonstrated.