Characterization of the Multipath Situation Under Meaconing Interference

With the escalating prevalence of in-band interference, the vulnerability of Global Navigation Satellite System (GNSS) receivers to potential jamming or spoofing threats has become a critical concern. The proliferation of GNSS repeaters, commonly known as meaconers (electronic devices that intercept GNSS signals, amplify them, and subsequently rebroadcast them) contributes to this threat landscape, by compromising GNSS accuracy, availability, continuity, and integrity of the nearby receivers. This paper investigates the impact of a meaconer on a GNSS receiver, when the received satellite signals are in the multipath situation (from the classification of Hussong et al. (2023)). The multipath situation is the situation when the meaconing useful GNSS signal affects the tracking of the authentic GNSS signal, as if it were exposed to a classical multipath. This paper characterizes and bounds the estimated carrier-to-noise ratio (C/N0) and tracking loop outputs in the multipath situation. Then, this paper identifies the geometrical conditions under which a satellite is affected by meaconing multipath. Finally, extensive simulations validate the mathematical models by comparing the expected C/N0 and tracking loop outputs to highly realistic simulation results. The findings reveal significant distortions in the C/N0 for satellites in the multipath situation. In rapid-dynamic scenarios, the C/N0 can decrease up to 20 dB.Hz, and C/N0 distortions may have more complex yet predictable patterns in slow-dynamic scenarios. The delay lock loop (DLL) outputs are shown to be corrupted by deterministic offsets up to ±15 meters, accompanied by increased standard deviations due to the degraded tracking performance caused by the meaconer interference.