Multipath performance analysis of GNSS navigation signals

Nowadays, multipath remains as an unsolved key problem for high precision applications, such as satellite navigation and position. Because GNSS broadcasted signals are subject to reflection and diffraction, just like any other type of electromagnetic waves, multipath is caused by the reception of direct signal together with the reflected or/and diffracted signals at the same time. Multipath will result in errors in pseudorange measurement and carrier phase measurement, and thus affect the positioning accuracy. To verify the effects of multipath propagation on positioning performance, the principle of multipath is introduced in the beginning of this paper. Then based on a simulation platform and mathematical verifying model, the multipath performance and its impact on positioning performance of received GNSS signal is comprehensively demonstrated from different aspects, such as pseudorange multipath error, waveform shape, modulation error, and correlation characteristics and so on. Results indicate the degradation of positioning performance when multipath signals were present, causing position error with several meters to tens of meters. Those results and data we have obtained from this paper could be used as a valuable reference for BDS future signal design and system constructions.