Apparatus and method for network level synchronization in multiple low earth orbit (LEO) satellite communications systems
US9749035B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 2015 |
| Grant date | Aug 29, 2017 |
| Priority date | — |
| Expiry date | Jun 25, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/185
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A synchronization approach is provided that compensates for the large Doppler offset of the satellites in a LEO satellite system by exploiting the predictable and deterministic nature of the Doppler component, and thereby simplifies the delay and the Doppler domain uncertainty ranges that the physical layer receivers have to resolve. The compensation is based on the known ephemeris information of the LEO satellite and the known positions of the gateway (GW) and the user terminal (UT) on the ground. Utilizing the deterministic component of the LEO Doppler, the synchronization process continually tracks and compensates for the time-varying offsets between the GW and UT frame timing, frame numbering (FN), symbol timings, and Doppler-induced scaling of center frequency and the signal bandwidth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.