Abstract: A satellite communication system in which a satellite receives a signal on a uplink carrier frequency, frequency translates it, and transmits the signal at a downlink carrier frequency. The downlink carrier frequency differs from the uplink carrier frequency by a standard frequency offset and a frequency offset error. A terminal earth station transmits to the satellite an inbound signal on the uplink carrier frequency. A hub earth station continually transmits to the satellite an outbound signal on an uplink carrier frequency and receives from the satellite the outbound signal at the downlink carrier frequency. The hub strips the outbound signal from the downlink carrier frequency and compares the stripped downlink carrier frequency to the reference carrier. A frequency offset error signal corresponding to the frequency offset error is generated.

Abstract: A satellite communication system has a hub earth station and a plurality of terminal earth stations. Each inbound satellite communication link from a terminal earth station to the hub earth station carries digital data packets encoded in CDMA code for code division multiple access at a first bit rate during synchronized time slots on a contention channel. An outbound communication link from the hub earth station to the terminal earth stations sends time division multiplexed digital data at a second bit rate higher than the first bit rate. A number of systems may share the same hub, with each system using a different CDMA code.

Abstract: A communication system includes a hub station and a plurality of terminal stations. An inbound satellite communication link from each of the terminal stations to the hub station sends digital data packets encoded with a CDMA code for code division multiple access during synchronized time slots on a contention channel. Each of the digital data packets is encoded with the same CDMA code during a first transmission, but each packet is encoded with an alternate CDMA code during any subsequent transmission.

Abstract: A compact electronic housing for a satellite earth station is described. The compact electronic housing comprises a first compartment and a second compartment separated by a panel common to both compartments. The first compartment contains electronic components and is atmospherically isolated from outside air and the second compartment. The electronic components comprise a plurality of groupings. The second compartment provides for movement of outside air into the second compartment through a bottom opening and out a top opening by a chimney effect cooling a plurality of heat exchangers. The panel dividing the two compartments comprises a plurality of conductive heat transferring elements for transferring heat from the electronic components to the plurality of heat exchanger element.