A Phase Bias Compensation Method for Anti-Interference Antenna Arrays in RTK Positioning

To achieve high-precision positioning using the global navigation satellite system (GNSS), the onboard GNSS receiver integrates real-time kinematic (RTK) technology to enable centimeter-level positioning accuracy. Furthermore, array anti-interference technology is incorporated into the RTK receiver to enhance positioning reliability and mitigate interference in complex environments such as urban areas or regions with high electromagnetic activity. However, this approach can introduce signal distortion, which adversely affects the convergence of RTK positioning. To address the issue of bias introduced by interference suppression in RTK positioning, this paper focuses on error modeling and bias compensation through a phase bias compensation algorithm. A novel phase compensation algorithm is proposed, leveraging the anti-interference weighting coefficients of array elements and the anti-interference output signal. Compared to the conventional minimum variance distortionless response (MVDR) algorithm, the proposed method features a simpler architecture and achieves phase compensation at a lower computational cost using the power inverse (PI) algorithm. Simulation experiments demonstrate the effectiveness of the compensation method, achieving a mean phase bias of approximately 0.25 degrees and a variance of 4.62 degrees. This level of accuracy makes it highly suitable for UAVs operating in challenging environments where precision and reliability are paramount.