| 摘要 |
PURPOSE:To attain the demodulation of a two-phase phase modulating signal at a desired time, by converting an orthogonal four-phase inverse modulator into a two-phase bipolar inverse modulator so as to attain the phase shift of a prescribed amount, in a demodulator of a four-phase phase modulating signal using the inverse modulation method as a carrier regenerating system. CONSTITUTION:A phase modulation (PSK) signal is inputted to an input terminal IN and demodulated at an orthogonal phase demodulator 1. Demodulated signals OUTs 1, 2 are inputted to a switching circuit 4. This switching circuit 4 converts the orthogonal four-phase inverse modulator 2 into the two-phase bipolar inverse modulator when the input PSK signal is a two-phase PSK signal, to switch the signal OUT 1 so as to be both modulating inputs to the inverse modulator 2. When the input signal is the four-phase PSK signal, the output of the inverse modulator 2 is inputted as it is to a jitter component eliminating circuit 3, and when the input signal is the two-phase PSK signal, the output is phase shifted at a + or -pi/4 phase-shifter 5 and inputted to the jitter component eliminating circuit 3. |
