3D ray launching and moment method for indoor radio propagation purposes

A 3D ray launching (RL) and a moment method (MM) based model are presented in this paper for an indoor environment. In the RL model direct, reflected and transmitted paths, and the wave polarisation and antenna pattern are taken into consideration and a special algorithm for finding the intersection points with the walls is used reducing the computational complexity of the model. The calculation of the transmission and reflection coefficient is performed by using measured material parameters and modelling the walls as homogeneous multi-layered dielectrics. Other construction materials and their inhomogeneous structure are being measured in order to make later refinements to the model. At places, where accuracy requirements are otherwise not met, the calculations are also done by the more complex moment method. The predictions given by the models are compared with measurements at 900 MHz for a modern office building. Results show good agreement with measurements, however call for the combination of the two methods for better results. In order to test the effect of the database inaccuracy, measurements were done also in an antenna measurement room at 900 MHz and the measurement results were compared with that of the RL model.