Position-Related Fundamental Limitation for Multipath-Assisted LEO Navigation

Yuxin He, Zihong Zhou, Bing Xu

Peer Reviewed

Abstract:	Achieving high positioning accuracy is crucial for applications at the LEO navigation scale, especially when only a limited number of cooperative LEO satellites are available. In this letter, we propose a new multipath-assisted LEO navigation (MALN) scenario that enhances LEO navigation by leveraging 3-dimensional urban environmental features as additional signal sources. Within The MALN scenario, virtual satellites (VSs) are generated by reflecting physical satellites’ signals off building facades using geometric optics principles, thereby increasing the effective number of LEO satellites available for navigation, especially in urban canyons. However, this urban model introduces uncertainties, primarily due to limitations in measurement precision, which can affect both signal propagation and the resulting positioning accuracy. Additionally, the amplitude of the reflected signals from VSs is affected by environmental noise. To quantify the impact of these uncertainties on LEO navigation, we introduce a probabilistic environmental model that accounts for the randomness in both the urban map and wideband channel characteristics. This model is treated as a priori knowledge and is rigorously integrated into the Fisher information matrix. This allows for the derivation of the squared position error bound (SPEB) in MALN scenario, which quantifies positioning accuracy. Numerical simulations show that as the subcarrier spacing (SCS), signal-to-noise ratio (SNR), and the number of visible physical satellites increase, the value of ? SPEB decreases, consistent with theoretical predictions about how these factors enhance navigation accuracy. These results confirm that incorporating environmental awareness into LEO navigation significantly enhances positioning accuracy, making it a crucial factor for achieving reliable LEO-based positioning in urban environments.
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:	3465 - 3478
Cite this article:	He, Yuxin, Zhou, Zihong, Xu, Bing, "Position-Related Fundamental Limitation for Multipath-Assisted LEO Navigation," Proceedings of the 38th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2025), Baltimore, Maryland, September 2025, pp. 3465-3478. https://doi.org/10.33012/2025.20464
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