GNU Radio Conference 2026

A Comprehensive Analysis of Large‑Scale SDR Synchronisation with the OctoClock‑G

24 Sept 2026, 11:45

15m

Mountain Ballroom (Talley Student Union)

Paper (with talk) Hardware in the Loop Main Track

Speaker

Mr Dennis Joosens (UAntwerpen - IDLab - imec)

Description

Large passive sensing systems operate by exploiting ambient Signals of Opportunity (SoOp). This makes precise timing and frequency alignment across multiple receivers essential for extracting coherent information. The National Instruments OctoClock‑G provides a shared reference that enables such synchronisation in multi‑receiver Software-Defined Radio (SDR) platforms.

The synchronisation behaviour of Universal Software Radio Peripheral (USRP) B210 SDRs connected through an OctoClock‑G remains under‑examined in existing literature. In particular, prior work does not assess how hardware variability across devices affects collective performance, nor does it offer an open‑source framework for orchestrating and reproducing multi‑receiver measurement campaigns. This gap limits researchers’ ability to evaluate system reliability.

In this work, we investigate the synchronisation performance of eight low‑cost USRP B210 SDRs driven by an OctoClock‑G reference. Measurements are conducted in an anechoic chamber across three Wi‑Fi bands and 11 gain settings, with particular attention to the reception of differences within the Industrial, Scientific and Medical (ISM) band. Our analysis quantifies the extent to which these devices can operate coherently under controlled conditions and identifies how hardware‑level variability manifests as measurable deviations in received signal characteristics. To contextualise these findings, we additionally evaluate two USRP X410 SDRs under identical conditions, enabling a direct comparison between entry-level and enterprise-level platforms.

The results provide a detailed view of system behaviour in ideal laboratory environments and are accompanied by open‑source software and a dataset that supports reproducible multi‑receiver experiments and further data analysis. By applying the same methodology to multiple hardware classes, we establish a comparative framework that highlights performance boundaries, stability trade‑offs, and the practical limitations of SDRs which can be relevant for passive sensing systems.