GNU Radio 4.0 for real-time signal-processing and feedback applications at FAIR

At FAIR, GNU Radio* is being used as part of the generic monitoring and first-line diagnostics for acceleratorrelated devices, and to further support equipment experts, operation, and FAIR users in developing basic to advanced top-level measurement and control loops. GNU Radio is a free and open-source software development toolkit supporting hundreds of low-cost to high-performance industrial digitizers with sampling frequencies ranging from a few MS/s to GS/s~\cite{gnuradio, gnuradio_github, gnuradio4_github, FAIR_Digitizer, FAIR_Digitizer2}. At its core are directed signal flow graphs expressing arbitrary post-processing and feedback control loop logic that are both numerically highly efficient as well as providing an intuitive yet detailed nuts-and-bolts representation. This facilitates to inspect and/or to reconfigure existing systems by accelerator-, control- or other system domain-experts alike with little to no prior required programming experience. This contribution describes the community-driven improvement and modernisation process leading to GNU Radio 4.0 supporting improved type-safety, improved performance, and new features such as event-driven data processing, nanosecond-level synchronisation using White-Rabbit, and slow feedback loops

GNU Radio

GNU Radio is a free & open-source software development toolkit that provides signal processing blocks to implement software radios. It can be used with readily-available, low-cost external RF hardware to create software-defined radios, or without hardware in a simulation-like environment. It is widely used in hobbyist, academic, and commercial environments to support both wireless communications research and real-world radio systems