Open-Source Multipath Mitigation Technology-Integrated GNSS Direct Position Estimation

Sergio Vicenzo, Bing Xu

Abstract:	Direct Position Estimation (DPE) was introduced as a Global Navigation Satellite System (GNSS) positioning algorithm that is robust against multipath (MP) as well as weak signals. Based on a Maximum Likelihood estimator, DPE solves the Position, Velocity, and Timing (PVT) estimates directly in the navigation domain, without estimating pseudorange and pseudorange rate measurements. Though extensive research has proved DPE superiority in comparison with the conventional two-step positioning (2SP), its performance still degrades in the face of MP and NLOS, which makes it still unsuitable for its application in urbanized environments. Furthermore, DPE applications in commercial receivers also remain unpopular. To that end, this paper proposes a new implementation of DPE, one that uses pseudoranges estimated by 2SP and can be readily applied into existing 2SP receivers. The second contribution is a Multipath Mitigation Technology (MMT)-integrated DPE. In essence, MMT cost function is integrated into DPE, allowing DPE to compensate additional path delays from MP reception. The proposed DPE and MMTDPE was evaluated with real static baseband signal urban data collected in Hong Kong, and the positioning results compared with unaided DPE and 2SP, as well as MMT-integrated 2SP (MMT-2SP). Results pointed out that the proposed DPE consistently outperforms 2SP in MP-only cases, highlighting that the proposed DPE architecture can replicate the inherent MP resilience in conventional DPE. MMT-DPE also consistently outperforms DPE in all the tested data, with outperformance of up to 35%. Under MP-only cases, both MMT-DPE and MMT-2SP perform similarly, as the MP reception has been compensated for both positioning methods. However, under non-line-of-sight (NLOS) reception, it was revealed that MMT-DPE manages to significantly outperform DPE, 2SP, and MMT-2SP, with outperformance of up to 60% against DPE, and 78% against MMT-2SP in the tested dataset, denoting that the proposed MMT-DPE strengthens the inherent NLOS mitigation properties of DPE.
Published in:	Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025) September 8 - 12, 2025 Hilton Baltimore Inner Harbor Baltimore, Maryland
Pages:	1391 - 1400
Cite this article:	Vicenzo, Sergio, Xu, Bing, "Open-Source Multipath Mitigation Technology-Integrated GNSS Direct Position Estimation," Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025), Baltimore, Maryland, September 2025, pp. 1391-1400. https://doi.org/10.33012/2025.20441
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