| 摘要 |
PURPOSE:To establish the carrier automatic phase control unit with simple constitution, by producing the timing signal equal in mark and space and the rectangular wave from the eye pattern, from the demodulation base band signal from the reception signal and comparing the both. CONSTITUTION:The reception signal a is demodulated 21 at the demodulation carrier j, and the base band signal k is produced via the LPF 22. The signal k is converted into the rectangular signal l by slicing the eye pattern at the comparator 23 and it is fed to the carrier phase control unit 28. On the other hand, the timing detector 25 detects the timing m of the center phase of eye pattern of the signal k, the timing signal generator 26 produces the signal n having equal space factor for mark and space, and it is fed to the control unit 28. The control unit 28 compares the signals l and n, takes the correlativity, produces DC signal p with integration, and control the phase of the carrier j so that the density in the changing point of the signal l can be symmetrical to the mark and space of the signal n via the carrier phase shifter 29. |
