A Receiver-Independent GNSS Smart Antenna for Simultaneous Jamming and Spoofing Protection

Abstract

It is well known that the presence of unintentional or intentional Radio Frequency Interference (RFI) signals in the Global Navigation Satellite Systems (GNSS) frequency bands can cause severe positioning performance degradation and even a complete service unavailability. Moreover, with the development of Software Defined Radio (SDR) GNSS signal generators and the popularization of low-cost SDR front-ends, the spoofing of the GNSS civil service turns out to be a real threat for GNSS receivers. Complementary to time and frequency-domain mit-igation techniques, antenna-array based receivers can benefit from spatial domain processing. An antenna array receiver can also discriminate between legitimate GNSS signals from these being broadcasted by the spoofer. In this work, we present an evolution of a receiver-independent GNSS smart antenna architecture for a real-time, automatic and autonomous, simultaneous anti-jamming and anti-spoofing spatial filtering for GNSS bands. The novel spoofer detection and mitigation algorithm is able to detect the spoofer and protect the receiver even in a scenario where the spoofer is transmitted in combination with a strong jammer to force the receiver to lose the legitimate GNSS signal lock. A prototype is also presented, implemented using Commercial Off The Shelf (COTS) components. The proposed smart antenna can be connected to any conventional single-antenna GNSS receiver. The paper includes both the theory of operation, the implementation details and its performance analysis in an extended measurement campaign.