Robust Ranging in the Presence of Repeater Signals

Abstract

This paper tackles the problem of robust Global Navigation Satellite System (GNSS) ranging in the presence of GNSS repeater signals. In such cases repeater signals act as an interference to GNSS satellite signals and need to be mitigated. The first contribution of this paper is the impact analysis of repeater signals on Delay- Locked-Loops (DLL), which are traditionally utilized for the time of arrival estimation in GNSS receivers. In the analysis, we determine different threat regions based on satellite signal and repeater signal parameters. Secondly, it introduces a novel algorithm that performs simultaneous channel estimation and equalization for GNSS signals. The proposed algorithm proves to be resilient in the presence of GNSS repeater signals in comparison to regular DLL structures. Finally, based on the inherent channel estimation the algorithm provides, it is possible to characterize the parameters of GNSS repeaters.