| 摘要 |
PURPOSE:To simplify the constitution of a system, and to regenerate easily a modulating signal by constituting a communication system by using a modulating signal of multilevel and multiphase, and regenerating stably a reference carrier wave from a receiving signal. CONSTITUTION:The IF signal of a receiving signal is inputted to a hybrid 1 of a demodulating system of a communication system and made to branch into two, and a part is supplied to a clock regenerating circuit 2 and a clock component is extracted. Also, a carrier wave is regenerated by a regenerating clock and a base band signal demodulated by a demodulator 4, by a carrier wave regenerating circuit 3. On the other hand, the IF signal made to branch and the regenerated carrier wave are supplied to the demodulator 4, and the base band signal is regenerated by demodulating the input IF signal. On this circuit 3, phase detectors 12, 13 connected to a hybrid 11, a base band processing circuit 14 for providing the output of the detectors 12, 13, sample holding circuit 17, VCO18, phase shifter 19, etc. are provided. In such a way, a reference carrier wave is regenerated stably from the receiving signal, and the constitution of a system is simplified. |
