A Multi-Modal Channel Sounding System for Environment-Aware Channel Measurements in 6G Dynamic Scenarios

Abstract

The deep integration of communication and sensing is widely recognized as a core 6G vision, underscoring the importance of comprehensive environment awareness. Accurate channel modeling forms the foundation of 6G system design and optimization, and channel sounders provide the essential empirical basis. However, existing channel sounders, although supporting wide bandwidth and large antenna arrays in selected bands, generally lack cross-band capability, struggle in dynamic scenarios, and provide limited environmental awareness. The absence of detailed environmental information restricts the development of environment-aware channel models. To address this gap, we propose a multi-modal sensing and channel sounding fusion system that enables temporally and spatially synchronized acquisition of images, point clouds, geolocation information, and multi-band multi-antenna channel data. The modular architecture facilitates rapid deployment in diverse dynamic environments. The system supports 10 MHz-44 GHz operation with up to 1 GHz bandwidth and 1 ns delay resolution, enabling multi-antenna measurements with a minimum switching interval of 8 microseconds. Moreover, it provides centimeter-level environmental sensing and meter-level positioning accuracy. Key metrological performance metrics, including an approximately 130 dB measurable propagation loss at 28 GHz, phase-coherent acquisition, calibrated channel response, LiDAR geometric correction, and bounded multi-modal synchronization margins, are validated through a vehicle-to-infrastructure measurement campaign. The established system provides a scalable experimental platform for environment-aware channel modeling, facilitating the development and evaluation of integrated sensing and communication technologies in future 6G dynamic scenarios.