| 摘要 |
PURPOSE:To improve the picture quality, by allocating a ringing wave caused by a phase jitter generated at phase lock return of a reproduced carrier wave within the period of generation of a phase signal. CONSTITUTION:A phase signal (k) picked up 31 from a residual side band signal i2 to be transmitted is applied to a phase holding signal generating circuit 35, where a phase holding signal (p) is obtained. This signal (p) is applied to an analog switch 32-3 of a phase lock circuit 32, where phase lock release, phase holding and return of phase lock of a reproduced carrier wave l2 are performed. A demodulation signal m2 is obtained by the synchronous detection of the signal i2 with the carrier wave l2. Taking the period of the signal (k) as 25ms and sum of times t4 and t5 as 17ms, since the period of a ringing wave (j) due to phase jitter is 5ms, the jitter is eliminated within the period of the phase signal. |
