secRTK -A Jamming Resistant RTK-Receiver: Prototype Architecture and Results of First Measurement Campaigns

GNSS receivers featuring both high accuracy and interferer resistance would be a very promising option for existing markets and could be the basis for new applications in the field of satellite navigation. This paper presents an architecture based on the concept of controlled radiation pattern antennas. The general idea and a receiver setup, which is based mainly on of-the-shelf hardware, are introduced. Central components of the presented demonstrator are a 2-by-2 rectangular multi-an-tenna array, a programmable 4-channel analog GNSS-frontend and FPGA-used for processing at intermediate frequency, an up-converter and RTK-receiver. This real-time demonstrator is used during measurement campaigns with and without interfering signals. Measurements without interfering signals prove that the overall architecture is functional, and the integrated RTK-receiver provides consistent and high accuracy localization. For a scenario without interfering signal, the results in this paper show scatter plots for single and multi-antenna configuration, which prove that the RTK fix state can still be reached within seconds for the combined antenna data streams. These measurements are done using a connection to the SAPOS® NRW service. A first test campaign on the vehicle dynamics area in Aldenho-ven Testing Center shows the behavior with controlled interfer-ence conditions for the static and dynamic case. Results compared with a commercial single antenna receiver show that spa-tial processing successfully rejects the interferer signals. Results under certain conditions of the test campaign are presented. While high-end hardware in the demonstrator provides sufficient processing capability for the prototype, algorithmic opti-mizations enable mapping to low-cost commodity FPGAs or highly optimized CMOS chip implementation for commerciali-zation.