A ray tracing algorithm for microcellular and indoor propagation modelling

A high speed 'image-based' ray tracing algorithm is presented that applies to both indoor and microcellular environments. The building database and image generation operates in two dimensions. However, for each 2D path, all the corresponding rays are calculated in 3D including multiple floor-ceiling reflections for the indoor case and the extra ground reflection for the outdoor scenario. The field calculation is implemented using dimensional vector analysis with each ray considered separately. To show the practicality of such models, the ray tracing engine has been used to investigate a microcellular environment in the centre of Bristol. The speed and complexity of the resulting model is investigated as a function of the number of reflection, transmission and diffraction generations.