| 摘要 |
PURPOSE:To improve the quality of a received signal by improving the stability by operation to phase follow-up operation by exercising automatic gain control by a variable gain circuit while obtaining follow-up characteristics for phase rotation by a carrier synchronous loop. CONSTITUTION:An input orthogonal amplitude-modulated signal is passed through a variable gain circuit 148 and demodulated by phase demodulation parts 127 and 128, whose demodulated signals are supplied to discriminating and regenerating circuits 145 and 146 through a transversal equalizer 130, thereby obtaining regenerated data. The regenerated data is supplied to a control-signal generating circuit 147; part of its output control signal controls the variable attenuating circuit groups 133-136, and 139-141 of the equalizer 130, and the other control signal is applied to a VCO129 to form a carrier-wave synchronous loop and to further control the gain of the gain circuit 148. |
