An adaptive frequency-based C/N0-constrained multipath extraction and mitigation method for GNSS pseudorange measurements

Abstract

The multipath effect poses an inevitable challenge for Global Navigation Satellite System (GNSS) receivers, particularly pronounced in smart devices, which are nevertheless the most common means through which the general public accesses GNSS positioning. So we propose a novel adaptive method for extracting multipath errors, which fully exploits the multipath frequency characteristics, multipath repeatability, and the correlation between multipath errors and carrier to- -noise ratio (C/N0). This approach aims to enhance the susceptibility of smart devices to multipath influences. Specifically, this method uses the code minus carrier (CMC) method to calculate the noisy multipath error,multipath to constrain the frequency range,exploits the correlation between C/N0 andemploys the ensemble empirical modedecomposition (EEMD) method to decompose the error signal, and utilizes the Hilbert–Huangtransform (HHT) method to obtain the frequency information of the signal component.multipath Inrepeatability, the proposed method can effectively improve the correlation ofmultipath signals by up to 0.79. By applying the extraction method, the positioning performance of smart devices can be improved by 13.9%. Therefore, the proposed method extracts multipath error more accurately and is highly usable in low-cost devices and real-time applications.