Over three European events, CHIRP demonstrated a low-cost, real-time radio channel sounder built on commercial FMCW sensors. By exploiting the interference between FMCW radars, it captures wideband channel samples without synchronization or cabling between devices, making high-frequency channel measurements, and the research and teaching built on them, far more accessible on the path towards 6G.
one6G Summit 2025 · Bologna, Italy
European Microwave Week 2025 · Utrecht, the Netherlands
EuCNC & 6G Summit 2026 · Málaga, Spain01The sounder
The demonstration is a real-time radio channel-sounding system built on commercial FMCW sensors operating at 79 GHz with 4 GHz of bandwidth. Rather than treating the interference between radars as a problem, the sounder uses it as the measurement itself: one sensor observes another's chirps and turns them into a wideband channel sample, with no shared clock and no cable between the two devices.
The system measures and visualizes both monostatic and bistatic channels, giving precise high-frequency channel information and real-time analysis that also holds in mobile scenarios.
02Hands-on at the booth
At the one6G Summit 2025 and at European Microwave Week 2025, the sounder ran live on the stand. Attendees were invited to add or remove scatterers around the sensors and watch the immediate effect on the power-delay profile, turning an abstract property of the radio channel into something they could change with their own hands.
one6G Summit 2025
European Microwave Week 202503Why cable-free matters
Conventional channel sounders need their transmitter and receiver to share a time and frequency reference, usually through cables or dedicated synchronization hardware. That requirement limits where measurements can be taken and how far apart the devices can be.
Because this sounder needs no cabling between devices, it can measure in complex environments, over longer distances and from drone-mounted platforms. It opens physical-layer studies in settings that were previously hard, or impractical, to probe, and which are essential to progress towards 6G. It also provides the real wideband measurements that AI-based channel models need for training and validation.
04Beyond channel sounding
The technique behind the sounder opens the door to other applications. At EuCNC & 6G Summit 2026 in Málaga, CHIRP also demonstrated one of them: a distributed sensing system that leverages multiple terminals and their mutual interference to localize people and track their trajectories.
It also raises a natural question for communications: can the same scheme be replicated to estimate the channel and equalize data symbols accordingly?
Live measurements
The team