Distortionless space-time adaptive processor based on MVDR beamformer for GNSS receiver

The utilising of space-time adaptive processing (STAP) can effectively enhance the globe navigation satellite system (GNSS) receivers' performance in suppressing harsh, sustained interference. However, STAP may introduce significant biases and distortions on the cross-correlation functions, which would deteriorate acquisition and tracking performance. To achieve high-accuracy GNSS applications in challenging environments, these biases and distortions must be mitigated. A novel distortionless space-time adaptive processor based on minimum variance disstortionless response (MVDR) beamformer is proposed. By combining the information of steering vector and constraining the taps number of tapped delay line to be odd, the proposed processor can maintain the linearity of space-time filter response and it introduces no biases into the code and carrier phase measurements. The effectiveness of the proposed processor is demonstrated by theoretical analysis and simulations.