Flexible Metasignal Tracking: Architecture Robustness in Challenging PNT Scenarios

Abstract

The idea of multichannel tracking is generally found in the Global Navigation Satellite System (GNSS) literature with a wideband approach. We further developed the concept to separately process two narrowband channels that are later combined in a dedicated delay-locked loop (DLL) in a virtual wideband fashion. To suit prospect evolution of positioning, navigation, and timing (PNT) technologies and GNSSs, we generalized the so-called meta-signal construction to the combination of components transmitted over the same bandwidth, thus expanding the range of candidate multichannel components and fostering efficient bandwidth exploitation and increased resiliency to harsh Doppler. These improvements are sustained by additional complexity at the receiver, whose robustness must be carefully assessed. The resulting architecture performance in presence of multipath and tracking noise is therefore characterized under the challenging conditions of modern GNSSs, focusing on a low earth orbit (LEO) PNT scenario. The technique can successfully bear the representative Doppler profiles and C/N 0 levels of the addressed scenarios achieving a large estimation noise reduction, even under challenging multipath conditions.