On-board regenerative repeaters applied to digital satellite communications

In pulse-code modulation/time-division multiple access (PCM/TDMA) satellite communications, though the number of repeating stage is usually only one, the regenerative repeater will be worthwhile enough to be introduced on board the satellite. This is because the improvement of the communication quality by the increase of the transmission power is difficult in the satellite link and the regenerative repeater is very effective for removing cochannel interferences which will become predominant factor of signal degradation in the future and it will also provide great facility for various kinds of on-board processings. This paper first presents basic configurations of the on-board regenerative repeater, and discusses about simplification of the repeater. Next various kinds of on board processings ate discussed in connection with the regenerative repeating. Then a concrete regenerative repeater applied to satellite switched/TDMA (SS/TDMA) satellite system which augments the communication capacity by frequency reuse is presented and compared with the conventional frequency translating type in terms of link budget, power dissipation, and weight. Lastly the result of the development of an experimental regenerative repeater is described.