| 摘要 |
PURPOSE:To minimize an error fluctuation of a phase difference and to obtain proper phase shift quantity information. CONSTITUTION:The circuit is provided With a variable delay circuit 2 receiving a baud rate clock (b) and a prescribed delay control signal (f) and delaying variably the baud rate clock (b) based on the prescribed delay control signal (f) to output a variable measured timing clock c' and with a delay quantity control circuit 5 generating the prescribed delay control signal (f) based on phase shift quantity information (d) to control the variable measured timing clock c' from the variable delay circuit 2. A phase quantity measurement circuit 3 measures the phase of a pi/4 shift QPSK signal (a) based on the variable measurement timing depending on the said variable measured timing clock c' to obtain the phase shift quantity information (d) from the pi/4 shift QPSK signal (a) between adjacent variable measurement timings. |
