Determining potential 30/20 GHz domestic satellite system concepts and establishment of a suitable experimental configuration

Issues and results in a NASA study of the potential concepts and markets for a multibeam 30/20 GHz domestic satellite system in the 1990s are presented. Issues considered include the reduction of signal attenuation due to rain, beam-beam interference isolation in the multibeam system, the method of access/modulation (FDMA, TDMA or hybrid) and the market for reduced reliability and wideband services. A hypothetical demonstration payload configuration which would attempt to resolve these issues is illustrated. The communications payload would employ a system of seven contiguous coverage spots in order to demonstrate a typical cell in a contiguous beam system having extensive frequency re-use, as in a direct-to-user system, and a single spot, typical of a trunking system, to determine signal isolation. The payload could be carried on several existing buses and is illustrated on an MMS bus.