Antenna arrays with adaptive filtering can protect the integrity and functionality of global navigation satellite system (GNSS) receivers against interference. However, a major problem with existing adaptive array processing algorithms is that they cause phase distortions and introduce bias errors into the carrier phase measurement, limiting high-precision applications. In this paper, a robust phase compensation technique is proposed to reduce the phase distortion. First, a phase bias detection method is developed to trigger the phase compensation technique. Then, the phase bias is estimated using a robust estimation method and compensated for in the GNSS receiver. The proposed technique operates in real time and causes no processing delay, while requiring only a minor modification to existing GNSS receivers. This technique is applied to the power inversion adaptive antenna, and can also be extended to a wide variety of adaptive antennas. The simulation experiments verify the applicability of the proposed technique and also confirm its superiority over existing techniques.

Adaptive antenna arrays are widely used to protect Global Navigation Satellite System (GNSS) receivers from interference. However, conventional blind anti-jamming array processing methods can cause satellite signal attenuation, which reduces signal tracking precision and measurement accuracy. To alleviate this problem, this paper proposes the noncoherent channel combining method for GNSS signal tracking with an adaptive antenna array. A two-stage processing architecture is applied in the proposed method, where the first stage implements interference suppression, and the second stage achieves noncoherent channel combining. The proposed method has the advantage of blind characteristics that can be implemented without any other auxiliary information. It also reveals a unified processing architecture for anti-jamming array processing methods. Thus, a detailed comparison and analysis of the proposed method with several typical blind anti-jamming methods is performed. Simulation results demonstrate the effectiveness of the proposed method and its superiority over existing methods in terms of tracking performance.

Multi-antenna Global Navigation Satellite System (GNSS) receivers with adaptive array processing are widely used in harsh jamming environments. However, spoofing is still a security threat to multi-antenna systems because it can go unnoticed by existing array anti-jamming techniques. Direction-of-arrival estimation is one possible technique to identify a spoofing attack. However, such methods are expensive to implement due to the need for array calibration. In this paper, a simple spoofing detection method with anti-jamming capability is proposed. This method can be operated without any supporting information or sensors, thanks to its blind characteristics. Specifically, multichannel anti-jamming processing is first used to suppress jamming, and then an extended double difference carrier phase (DDCP) model is established. Based on the above, a test statistic for spoofing detection is derived using the generalized likelihood ratio test (GLRT) approach. The detection performance is analyzed theoretically and the detection threshold is derived. Furthermore, methods to reduce false alarms are also discussed. Finally, several real-world experiments are performed to verify the effectiveness of the proposed method.