| 摘要 |
PURPOSE:To recover a carrier signal from which the effect of disturbance is excluded as to an orthogonal frequency multiplex signal through a transmission line in which multi-path disturbance or the like is in existence. CONSTITUTION:I channel signal and a Q channel signal outputted from parallel/ serial conversion circuits 122, 123 are received by a selection circuit 1532 of a carrier signal recovery circuit 153. The selection circuit 1532 inputs only a demodulation signal of a frequency component corresponding to a predetermined carrier signal from the demodulation signals to a phase detection circuit 1533. A phase error output detected by the phase detection circuit 1533 is inputted further to a D/A converter circuit 1534, in which the signal is converted into an analog signal, an undesired frequency component is eliminated from the analog signal by a low pass filter 1535 and the result is a voltage signal controlling a local oscillator 113. The local oscillator 113 generates the carrier signal having a frequency corresponding to the voltage signal. Through the constitution above, a phase error with the recovered carrier signal is detected based on one specific carrier signal to control the local oscillator 113. |
