Abstract: A VSAT satellite communications network utilizes parallel concatenated coding on its inbound or outbound links, or both. For short data blocks, nonrecursive systematic tail-biting convolutional codes are used. For longer data blocks, recursive systematic convolutional codes are used. These parallel concatenated coding techniques are used in conjunction with spread-spectrum modulation to provide a VSAT communications system which meets FCC regulations on the total power spectral density of transmitted signals as well as mitigates interference from adjacent satellites.