Site diversity switching experiments using CS K-band satellite links

An experimental site diversity switching system (SDSS) and tests of a model SDSS system with the Japanese communication satellite (CS) are reported. The SDSS system involved an earth-satellite link using PCM/PSK/TDMA. The SDSS features 10-m antenna stations with PSK modems. The main station has a TDMA terminal and switching control apparatus. The system has synchronization and diversity switching, i.e., route selection and 8000 error bits monitored per burst packet. Experiments examined the variable delay line control, downlink switching control and time measurement by the Constant Time Method, i.e., counts of the number of error bits, and by modeling signal qualities. The tests validated the functions of the SDSS technique and characterized the optimal Constant Time Method measurement period as slightly longer than one satellite spin.