5G • Services
NTN Doppler Compensation
Satellite Doppler Shift Compensation
Pre-compensation mechanisms where UE and satellite pre-shift radio carrier frequency to counter high orbital speed.
Technical Explanation
Because LEO satellites travel at 27,000 km/h, received carrier signals suffer Doppler shifts of tens of kilohertz. In 3GPP NTN, the satellite broadcasts ephemeris trajectory data. The UE uses its GNSS coordinates and satellite ephemeris to calculate relative velocity and pre-compensate its transmit frequency.
Key Functions
- Pre-compensates carrier frequency offsets caused by 27,000 km/h satellite velocity
- Uses satellite ephemeris trajectory and UE GNSS location to compute offset
- Prevents severe inter-carrier interference on the 5G OFDM grid
Specifications
3GPP TS 38.211, TS 38.213
Interfaces
Uu
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