| 摘要 |
PURPOSE:To simplify the phase control of a demodulated carrier when a base band signal is detected and the deterioration of an error rate is detected, and using a timing signal to control the phase. CONSTITUTION:A demodulated carrier reproducing circuit 1 reproduces a demodulated carrier F from a reception signal A. An automatic equalizer 3 inputs a demodulated base band signal B of a demodulation circuit 2, eliminates interference between codes to decide each signal level of multi-value and a decision result signal is fed to a decoder 4. The decoder 4 reproduces an original code series C and supplies an error detection pulse to an error rate deterioration detecting circuit 6. A base band signal detection circuit 5 counts a detection signal D representing the presence of the said signal B and the circuit 6 counts an error detection pulse and applies an error rate deterioration signal E to a phase control circuit 7. The phase control circuit 7 has a timing signal generating means and a variable phase shifter, uses the signals D, E and the said timing signal, applies the phase of the carrier F to the variable phase shifter, which is controlled and the controlled demodulation carrier G is fed to the demodulation circuit 2. |
