FM-SCPC system and equipments for satellite communication

It is planned that one of the K-band transponders of a Japanese communications satellite will be used for small traffic communications. In order to establish the small capacity communications system, the Signal Channel per Carrier (SCPC) system operating in 30/20 GHz band is being considered as part of the Medium Capacity Communications Satellite for Experimental Purposes (CS), and small-size earth stations and SCPC terminal equipment have been developed by Radio Research Laboratories. The FM-SCPC system, in which the S/N of the voice signal is improved by using syllabic companding technique, is useful in the SCPC system. In addition to voice signals, the digital signals of facsimiles, still pictures, etc., can be transmitted. This paper describes the outline and the design concept of the FM-SCPC system. The constitution and the performance of the FM-SCPC modem which was developed based on this concept are described.