GPS Interference Cancellation Performance in Single and Multiple MVDR Beamforming Methods

Dual-polarized adaptive antenna arrays are an effective technology for interference nulling. It can be applied prior to delay lock loops in Global Positioning System (GPS). The optimum cancellation weights can be selected based on the minimum variance distortionless response (MVDR) criterion. However, when the interferer is close to one of the satellites, the MVDR fails to lower the interference-to-signal-and-noise ratio and also leads to irregular and undesirable array response. The solution is to use one set of weights for each satellite, and, as such, isolate this failure to one satellite, rather spread it to all satellites in the field of view. The paper compares single vs. multiple beam MVDR GPS receivers under different interference location and polarization.