| 摘要 |
PROBLEM TO BE SOLVED: To satisfactorily reproduce a carrier concerning each of modulated waves, even when mutually different multi-phase modulated waves are multiplexed in time-division manner to decode a transmitting symbol, even when C/N is low. SOLUTION: When the receiving C/N is high, all 8PSK modulated main signal, QPSK modulated main signal, BPSK modulated main signal and TMCC and phase reference burst signal operate at a prescribed gain. When the receiving C/N is lowered, the gain of the 8PSK modulated main signal becomes zero, and the gain of a period subjected to QPSK and BPSK modulation increases. When the receiving C/N is further deteriorated, the gain during a period of OPSK modulation becomes zero as well, and the gain during the period of BPSK modulation is further increased. Thus, even if the C/N is low, the carrier can be reproduced correctly. |
