ROMJIST Volume 29, No. 2, 2026, pp. 179-190, DOI: 10.59277/ROMJIST.2026.2.07
Mirela SORECAU, Emil SORECAU, Alina-Cristina BUNEA, Dan NECULOIU, Florin POPESCU, Ionut Alexandru RADU, Paul BECHET Real-Time Spectrum Monitoring for Unmanned Aerial Vehicle Radio Frequency Signature Using a Multi-Channel Software-Defined Radio Architecture
ABSTRACT: This paper presents the design and experimental validation of a wideband, real-time spectrum monitoring system implemented on a multi-channel software-defined radio (SDR) architecture. The platform utilizes a USRP X310 equipped with dual TwinRX daughterboards to provide four independent receive chains. It has been demonstrated that a RFNoC-based acquisition chain performs FPGA rate reduction, while host-side processing in GNU Radio applies high-resolution FFT based spectrum estimation and real-time visualization. A spectrogram graphical user interface (GUI) is presented, incorporating percentile-driven auto-leveling with smoothing and display-domain frequency pooling to enhance wideband readability. A concatenation and trim method facilitate stitched wideband observation in the 5.8 GHz band. Controlled laboratory measurements in the 2.4 and 5.8 GHz ISM bands, including sweep injection and multi-UAV scenarios under Wi-Fi congestion, confirm stable real-time operation, continuity across the stitching boundary, and clear visibility of dominant drone downlink activity.KEYWORDS: Drone detection; ISM 2.4/5.8 GHz; multi-channel; SDR; spectrogram; widebandRead full text (pdf)