Experiments on SCPE communication system using 30/20 GHz band transponder of the CS

The results of various experiments using the 30/20 GHz band transponder of the CS conducted to establish SCPC systems for practical use are discussed. The C/N(0) characteristics of links between the main fixed station and small earth stations agreed with results obtained by link parameter calculations. The bit error rate or S/N characteristics are also reported. The intermodulation interface due to transponder nonlinearity was investigated, and the group assignment method is found to be useful for channel reassignment to decrese the intermodulation interference. The qualities of voice, facsimile, and still picture signals transmitted through the CS link were good enough for use, and there was little interference between the terrestrial link signal and the down-link signal. Disaster communications experiments proved the usefulness of the Common Channel System and the availability of the link controller. The necessity for network control stations in the SCPS system was also investigated.