Tutkielma satelliittipohjaisen paikannuksen sietokyvyn parantamisesta antenniryhmän signaalinkäsittelyllä

Intentional jamming and spoofing, in addition to unintentional interference, challenge the use of global navigation satellite system (GNSS) signals. Although array processing can improve the interference resiliency of radio systems compared to single-antenna receivers, export regulations and implementation complexity have slowed its wider adoption. A recent regulatory change in the United States removed interference- resilient civilian arrays from the munitions list, easing deployment of the technology in a broader range of applications. Furthermore, next-generation GNSS constellations will employ higher carrier frequencies, enabling more elements in arrays of comparable physical size. This thesis surveys known array signal processing methods for GNSS receivers and evaluates a subset of them experimentally. From the literature, spatially constrained power-minimization methods were found suitable when satellite signal directions of arrival are known in the array frame, as they preserve the desired signals without distortion. Techniques based on the known satellite transmission waveforms may risk locking onto spoofed signals while blind techniques make the array spatial phase response unstable. The experimental part uses Jammertest 2024 data collected with a four-element planar array to assess two blind mitigation techniques. The results show that even a small array can significantly improve interference-resilience and that selected techniques can be integrated with existing GNSS receiver architectures.