6G • RAN
Channel Knowledge Map (CKM)
Site-Specific 3D Electromagnetic Environment Spatial Database
Location-indexed digital map storing historical radio propagation channel characteristics to eliminate costly online pilot channel training.
Technical Explanation
In massive MIMO and sub-THz communications, sounding the wireless channel using pilot reference signals consumes enormous overhead. The Channel Knowledge Map (CKM) is a high-resolution 3D geospatial database indexed by terminal coordinates. It stores historical channel path losses, angle-of-arrival, delay spreads, and line-of-sight blockage maps. By querying the CKM with the user's GPS or radar coordinates, base stations configure initial beamforming states instantly with zero pilot sounding overhead.
Key Functions
- Stores fine-grained 3D spatial radio channel statistics mapped to physical coordinates
- Eliminates real-time pilot channel sounding overhead for beam alignment
- Predicts non-line-of-sight blockages before mobile terminals walk behind obstacles
- Enables instant zero-latency link establishment for high-mobility vehicles and drones
Specifications
IEEE Wireless Communications CKM Feature, 3GPP Rel-19 Spatial Map Studies
Interfaces
CKM Geospatial Database QuerygNB Beam ConfiguratorTerminal Positioning Engine
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