5G • RAN
TCI State
Transmission Configuration Indicator State
Configuration indicating Quasi-Co-Location (QCL) relationships between target data antenna ports and source reference signals.
Technical Explanation
A Transmission Configuration Indicator (TCI) State tells the UE that the channel properties (Doppler shift, delay spread, spatial receive filter) of a data channel (PDSCH or PDCCH) are quasi-co-located with a known reference signal (SSB or CSI-RS). The gNodeB dynamically activates TCI states via MAC CE and indicates the active state via 3 bits in DCI.
Key Functions
- Configures Quasi-Co-Location (QCL) relationships for data and control channels
- Instructs UE which spatial RX beam and tracking parameters to apply
- Activated via MAC CE and dynamically switched via 3-bit DCI field
Specifications
3GPP TS 38.214
Interfaces
Uu
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