Vector Tracking with a Multi Antenna GNSS Receiver

Abstract

In digital beamforming receivers the tracking of satellite signals which have a similar direction of arrival like the interference source often lose lock. A very difficult and time consuming reacquisition is the consequence. Especially in scenarios with moving receivers or RFI sources, gradually all satellites might get lost due to the change of the directions of arrival between the satellite signals and the RFI source. In single antenna receivers a very similar effect can be observed in urban canyons. According to the movement of the receiver different parts in the receiver’s skyplot are obstructed due to buildings or other obstacles. Vector tracking is a well-known technique to improve the GNSS availability in such scenarios. This paper describes an approach to integrate a vector delay and frequency locked loop (VDFLL) in a digital beamforming receiver. The proposed architecture consists of a pre-correlation prewhitening module and a VDFLL with an integrated post-correlation eigenbeamformer. The architecture of this approach will be described in detail and the potential capabilities will be shown by the results of a measurement campaign with a personal privacy device jammer.