Performance Analysis of GNSS Adaptive Nulling Algorithm Under Signal Power Enhancement

In general, the accuracy and reliability of the GNSS receivers are seriously threatened by interference because the satellite signal arriving at the receivers is extremely weak. Under weak signal conditions, adaptive nulling based on antenna array has been proved to be the most effective interference mitigation method. In the context of navigation war, it has become a strategic to improve the satellite signal power through power-enhancement. Under this condition, the weak signal assumption will no longer hold on and whether adaptive nulling anti-jamming method is still effective deserves further study. In this paper, the adaptive nulling performance under satellite power-enhancement conditions is analyzed, the results show that, under weak interference condition (the interference-to-signal ratio (ISR) is less than 30 dB), the adaptive nulling algorithm will partially suppress the satellite signal when the power enhancement exceeds 20 dB. While when the ISR exceeds 40 dB, the adaptive nulling algorithm will mainly suppress the interference, and the attenuation of satellite signal is ignorable. From the perspective of the final navigation and positioning performance, the current adaptive nulling anti-jamming algorithm is still effective under power-enhancement conditions.