| 摘要 |
PURPOSE:To reduce a data error rate by outputting demodulation data included in a synchronizing period when no slip in a demodulation phase takes place for the long period and outputting demodulation data included between fixed words when the slip takes place. CONSTITUTION:A fixed word is inserted in a transmission signal in advance for a shorter period than the period when a slip of a demodulation phase takes place. A correlation device 2 calculates the correlation with respect to a demodulation signal including a fixed word to be inputted in a long frame timing from a generator 5. Then an estimate circuit 3 receives the result of calculation, outputs a demodulation phase, an absolute value circuit 6 receives the result of calculation to calculate an absolute value. When the absolute value is larger than a threshold level decided in advance at a comparator circuit 9, it is discriminated that there is no slip in the demodulation phase and the circuit 3 outputs the estimated demodulation phase. When the absolute value is smaller than the threshold level, it is discriminated that a slip takes place and the estimated demodulation phase is switchingly outputted by an output of the correlation device 2'. Thus, a correct demodulation phase is always outputted. |
