Real-world Latency Analysis of Vehicular Visible Light Communication with Multiple LED Transmitters and an Event-Based Camera
Up to three LED transmitters handled simultaneously in real-world driving tests, meeting cooperative perception latency.
A team led by Ryota Soga from Nagoya University has demonstrated a novel visible light communication (VLC) system that uses event cameras as receivers for vehicle-to-everything (V2X) applications. Event cameras offer exceptionally high temporal resolution (microsecond-level), low latency, and wide dynamic range—ideal for capturing fast-changing LED signals in driving environments. However, previous event-camera VLC systems suffered from bandwidth saturation (too many events in bright scenes) and struggled with multiple transmitters. The researchers addressed these by adopting a 'positive-event-only' mode (ignoring negative intensity changes) and designing a custom protocol that controls event generation per pixel. This keeps the data rate manageable while preserving the wide field of view and communication distance needed for real driving.
The system also introduces a method to identify and lock onto multiple LED transmitters by exploiting spatial separation and timing patterns. In tests, it successfully received simultaneous signals from up to three LED headlights. Most importantly, the team measured end-to-end latency—from LED emission to event detection and decoding—in real vehicular scenarios. Results show that the system meets the strict latency requirements for cooperative perception (e.g., sharing obstacle detection between cars), a key feature for autonomous driving. This work suggests that event-camera-based VLC could become a low-cost, low-latency complement to traditional RF-based V2X, especially in dense traffic where RF interference is high.
- System uses positive-event-only mode plus a custom protocol to suppress bandwidth saturation while maintaining distance and field-of-view.
- Novel multi-transmitter identification handles up to three LED sources simultaneously for the first time in event-camera VLC.
- Real-world driving tests show end-to-end latency meets cooperative perception requirements (< 100 ms, typical for V2X safety applications).
Why It Matters
Could enable ultra-low-latency, low-cost V2X communication using existing car LEDs and event cameras, complementing radio-based systems.