High-Precision LEO Satellite Localization Systems: When Rydberg Atomic Receiver Meets RIS

Abstract

To address issues such as insufficient reception sensitivity and decreased positioning accuracy faced by traditional satellite positioning systems in scenarios like urban blockage, long-distance transmission, and weak signal reception, this paper studies a low Earth orbit (LEO) satellite uplink positioning method based on a Rydberg atomic receiver (RAR) assisted by a reconfigurable intelligent surface (RIS). First, a positioning system model composed of ground user equipments (UEs), RIS, and multiple LEO satellites equipped with RARs is constructed, jointly considering the direct link from the UE to the satellite as well as the UE-RIS-satellite reflection link. Second, utilizing the non-stationary effects of quantum spatial coding in RAR, the angle of arrival and Doppler shift information are extracted from signals received by the satellite, and a surrogate layer, a mapping layer, and a fusion layer hierarchical positioning algorithm, termed SMF-RIS framework is proposed, achieving user position estimation through alternative variable estimation, physical quantity mapping, and position fusion. Finally, the effectiveness of the proposed method is verified through simulation results of positioning error cumulative distribution function, observation signal-tonoise ratio, and the number of RIS elements. The results show that compared to schemes without RIS and traditional metal antenna reception schemes, the proposed RAR-RIS method can significantly reduce positioning error, and as the number of satellites, observation signal-to-noise ratio, and the number of RIS elements increase, the system positioning accuracy is further improved.