A new TDMA system for domestic service and its high speed PSK modem

A new TDMA system model for application to domestic satellite communication in Japan is described. Multiple-transponder operation using a variable routing system is introduced, which will be useful for construction of flexible networks and reduction of earth station installations for the TDMA system. In the variable routing system concept, each earth station has PCM signal switching function, namely a system switch which sets transmitting and receiving PCM signals of a PCM codec to connect to a selected multiplexing and demultiplexing circuit of multiple TDMA equipments, respectively. Results are presented for the following experiments intended to confirm the realization of the proposed TDMA system: coherent clock synchronization experiment at 100 MHz clock frequency for maintaining burst synchronization in TDMA operation, and carrier recovery experiment of a high-speed PSK modem using 1.7 GHz carrier frequency. Synchronization schemes are designed to maintain the burst synchronization against precipitation in the 20/30 GHz frequency band.