Optimized implementation of the 3D MR-FDPF method for indoor radio propagation predictions

With the widely acceptance of WiFi networks, and the highly regarded development of new indoor technologies like distributed antenna systems and femtocells, propagation models that take accurately into account the indoor channel characteristics are necessary for the purpose of network planning. Due to the complexity of such indoor environments made of obstacles causing numerous reflexions and diffractions, full 3D indoor propagation models are required. The MR-FDPF was recently proposed for indoor radio coverage but suffered from high complexity when trying to extends this model to 3D. That is why in this paper a solution to reduce the complexity of the MR-FDPF method is provided. In this new approach, the size of the matrices to be inverted is reduced, by neglecting the propagation modes that have low influence on the resulting coverage. It can be shown that propagation matrices of large MR-nodes can be divided into two classes, i.e. standard flow matrices and return flow matrices, each one having its possible simplifications. This new model allowed us to run full 3D simulations on a 3-floored building, with a RMSE of about 4dB between simulation and measurements.