| 摘要 |
An automatic frequency control system (30) for use in satellite communications (10, 20, 30) is provided that is preprogrammed with an initial acquisition Doppler offset frequency. The system (30) includes a search mode for accurately determining the satellite's initial frequency translation error before the initial of data transmission and also for determining the Doppler rate of change. The system (30) further includes a tracking mode, in which the frequency variation is continuously monitored. Depending on the frequency characteristics of the transmission, the system (30) is capable of re-entering the search mode to determine a new frequency translation error, if necessary.
|
