| 摘要 |
PURPOSE: To suppress the generation of the communication error of a superhigh speed modem and to remarkably improve the characteristic by providing the carrier phase control circuit composed of a frequency offset prediction part and a phase segment fluctuation elimination part on the reception side of a transmitter. CONSTITUTION: A carrier phase control circuit 1A is provided on the reception side of a transmitter and is interposed between an automatic equalizer 2 and a signal decision part 3. The circuit 1A is composed of a frequency offset prediction part 4 and a phase segment fluctuation elimination part 5. The prediction part 4 predicts the deviation of the frequency of a transmission signal based on the output of the equalizer 2 and eliminates the deviation, the elimination part 5 predicts the phase segment fluctuation of the transmission signal based on the output of the prediction part 4 and eliminates the fluctuation, and the outputs are inputted in the decision part 3. Therefore, for the signal from the equalizer 2, the frequency offset and the phase segment fluctuation can be eliminated. When the circuit is applied to a superhigh speed modem, the generation of a communication error is suppressed and the characteristic of the modem can be remarkably improved. |
