GPS Multipath Modeling Based on Propagation Environment Digitization and Ray-Tracing Technique

The objective for modeling GPS multipath is to enable the tesing of multipath mitigation techniques in a fairly realistic environment. An approach for GPS multipath modeling is presented in this paper. Firstly a digital model for approximating the real GPS signal propagation environment is built. Based on this environment model, the ray-tracing technique is employed to determine all the propagation paths from the GPS satellites to the receiver antenna. At the receiver antenna for each path the received signals' parameters, i.e. amplitude, delay and phase, are obtained by the electromagnetic computation. Finally the simulation experiment to verify the multipath model is conducted. This multipath modeling proposed in this paper was applied to the navigation simulater to generate navigation signals which is processed by a receiver. By comparing the tracking and positioning status of receiver with multipath and without multipath, this GPS multipath modeling is preliminaily validated.