Basic block diagram of satellite communication

• Users are the ones who generate baseband signals, which is processed at the earth station and then transmitted to the satellite through dish antennas. 
• Now the user is connected to the earth station via some telephone switch or some dedicated link. 
• The satellite receives the uplink frequency and the transponder present inside the satellite does the processing function and frequency down conversion in order to transmit the downlink signal at different frequency. 
• The earth station then receives the signal from the satellite through parabolic dish antenna and processes it to get back the baseband signal. 
• This baseband signal is then transmitted to the respective user via dedicated link or other terrestrial system.