SDR System for Real-Time FHSS Communications Detection and Jamming

This study presents the development of a software-defined radio (SDR) system for automatically detecting frequency-hopping signals and generating targeted jamming on them. The system is set up on the GNU Radio platform, using an ADALM-Pluto transceiver and custom function blocks in Python. This includes an adaptive threshold detector designed to analyze noise level dynamics and trigger automated responses. Real-time detection of active frequencies allows for precise initiation of RF jamming sequences, making the solution effective in situations where a quick reaction is necessary. Validation was achieved through a series of laboratory tests using both simulated signals and real transmissions with frequency hopping rates of up to 1000 frequency hops per second. The experimental results show that the system reliably identifies spectral activity and can apply coherent and localized jamming in the vicinity of the directional antenna. The results show that the system can be used to monitor radio frequencies and to create electronic countermeasures (ECM) against frequency agile communications.