3D Multi-GNSS Over-The-Air Wave Field Synthesis Testbed

This paper presents a novel three-dimensional (3D) over-the-air (OTA) wave field synthesis (WFS) testbed designed for global navigation satellite systems (GNSS). Unlike traditional conducted and open-field tests, which are limited in realism, the 3D OTA WFS approach enables the realistic emulation of various GNSS scenarios under controlled and repeatable conditions. This allows for effective comparisons of receivers and algorithms, particularly for those utilizing multi/beamforming antenna technologies. The setup used for these tests features a GNSS simulator, an OTA channel emulator and 16 dual-polarized antennas installed within an anechoic chamber. The validation measurements demonstrate the capability of the system to produce high-quality electromagnetic fields across the upper hemisphere of the chamber. The capability for precise GNSS emulation is validated by comparing results with real-world outdoor measurements using the carrier-to-noise-density ratio (C/N0) metric. The big advantage of the emulation lies in the total control of the scenario, which means that random effects such as multipath propagation and scattering could be neglected in case it is required. However, these effects can also be included in the emulation, as shown in the final results of this contribution. In order to show the versatility of the emulation, the analysis of a GNSS jamming attack is also included to assess the performance of an anti-jamming system. The OTA approach allows for comprehensive testing, addressing issues of antenna gain patterns and signal reflection impacts on performance. The findings illustrate the advantages of the 3D OTA WFS setup for emulating GNSS signals. The results underscore the potential for improved reliability and accuracy in GNSS performance evaluations, thereby advancing research in integrated GNSS technologies.