Characteristics of 100 Mbps TDMA and FM signals transmission mode sharing a single communication transponder

Field trials have been carried out to confirm the feasibility of sharing a wide-band transponder with 100 Mbps TDMA and FM-TV signals using Communications Satellite. The fundamental characteristics and the distortion caused by sharing a single wide-band transponder with the TDMA and FM signals was experimentally investigated. The transponder output power decreases per carrier, which was caused by two carrier common amplification, was about 4.7 dB. The multimodulation transfer noise imported into the FM signal from the envelop variation of TDMA signal was observed in FM link and was estimated at less than 1.3 dB near or at the TWT saturation region. The link budget of the TDMA and FM links was calculated considering these distortions and the common amplification of TDMA and FM-TV signals was experimentally confirmed.