Carrier regenerating device

Abstract

Abstract PURPOSE:To secure an escape for the loop out of the false lock state, by giving a forced increase to the oscillation frequency of the voltage control oscillator in case no specific phase relation is secured between the input carrier signal and the regenerated carrier signal. CONSTITUTION:The deciding circuit 30 gives a decision to the phase relation between the PSK (digital phase modulation) wave produced by modulating the input carrier via the data and the output of the modulator 15 obtained by modulating the regenerated carrier with the demodulated data. Then the output of the phase fre- quency comparator 21 is applied to the voltage control oscillator 13 via the LPF12 and in the form of the control signal. And thus the oscillation frequency is conrolled to secure a constant phase difference between the both carriers. In case no coincid- ence is obtained between the both carriers, the control circuit 40 gives a forced increase to the oscillation frequency of the oscillator 13 based on the output of the circuit 30. As a result, an escape is secured for the loop out of the false lock state.

Inventors

• 👤 Tsukasa Okai
• 👤 Fumio Sugiyama

Bibliographic Details