| 摘要 |
PURPOSE:To bring the adverse effect of composite modulation onto a carrier lock time to endlessly zero when the synchronization detection system is adopted for an orthogonal phase detection means of a composite modulation wave and to establish the synchronization system between a main data signal and a sub data signal. CONSTITUTION:A sub data transmission signal is sent in a frame form consisting of a preamble signal SP giving sub data control information with phase modulation alpha=0, of a unique word signal UW to synchronize a sub data signal and a main data signal, and of the sub data, and a demodulator side establishes the frame synchronization of the sub data when the unique word signal UW included in the sub data series is detected to eliminate a phase ambiguity of the main data signal and the sub data signal, and the phase of the carrier is synchronized quickly in the case of the preamble signal SP and in the case of the undetected unique word signal UW. |
