Carrier Phase Bias Correction for GNSS Space-Time Array Processing Using Time-Delay Data

Abstract Due to low transmitting power, GNSS signals are so vulnerable that can be easily jammed by accidental or malicious interference. The space-time array processing (STAP) technology is the most effective way for anti-jamming, but the undesired bias would be introduced by STAP leading to distortion of signals. To solve this problem, traditional methods usually calibrate antennas together with applying distortionless algorithms. However, the calibrating is burdensome and cannot be batched, while most of distortionless algorithms require the information of signal direction, so these methods are not applicable in general array receivers. This paper proposes the time-delay carrier phase bias estimation (TD-CPBE) algorithm for STAP bias correction, which does not need antenna calibration or signal direction information. TD-CPBE locates changing moments of jamming, estimates the STAP introduced carrier phase bias by open-loop tracking of time-delay data, and corrects it by phase shift in tracking procedure. The simulation results show that TD-CPBE can effectively correct STAP carrier phase bias with residual error less than 3°, which is close to that of traditional distortionless algorithm, and the open-sky experiment further verifies the proposed algorithm. Since TD-CPBE requires much less prior information, it is a very effective and applicable method for STAP carrier phase bias correction.