MOBILE TERMINAL WITH FREQUENCY LOCK LOOP

摘要

A mobile terminal for satellite communications receives communication, e.g., from a gateway via a satellite link. A frequency lock loop unit locks to the carrier frequency of the received communication. The mobile terminal includes a global positioning system for receiving global positioning data. The mobile terminal determines the Doppler frequency shift of the received communications based on the global positioning data. The mobile terminal generates a reference clock for return transmissions based on the frequency of the frequency lock loop, corrected for the Doppler shift. A correction factor of two times the determined Doppler frequency shift is used, to compensate for both a forward and return transmission link.

主权项

1. A mobile terminal comprising a computer including a processor and a memory, the memory storing instructions such that the processor is programmed to:
cause a reference signal that has been extracted from a received signal to be provided to a frequency lock loop to generate an output reference clock based on the reference signal; instruct a frequency synthesizer to generate a return carrier based at least in part on the output reference clock; and instruct a transmitter to transmit a return transmit signal based at least in part on the return carrier.