Q9Satellite Communication
Question
Q.9. List out the types of modulation scheme employed in satellite communication.
Answer
An onboard atomic/crystal reference oscillator (frequency synthesizer/local oscillator) is used within the satellite transponder to maintain the communication frequency of the signal accurately and stably.
A highly stable frequency reference — typically a precision crystal oscillator, sometimes disciplined by an atomic frequency standard on navigation satellites — is used within the satellite transponder's local oscillator/frequency synthesizer chain to maintain the accurate and stable communication frequency required for correct up/down frequency conversion within the transponder; frequency stability is essential to keep the transponder's translated downlink frequency precisely within its assigned frequency plan/band and to avoid interference with adjacent channels or satellites operating nearby in the frequency spectrum.