| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a demodulation apparatus capable of quickly obtaining stable carrier synchronization against the frequency deviation of a recovered carrier caused at channel switching or the like even when distortion due to reflection or the like exists. <P>SOLUTION: The demodulation apparatus provided with a carrier recovery circuit including: a circuit (4) for complex-multiplying (3) an error evaluation value obtained from a demodulation signal with a modulation input signal U to obtain an updated signal E and updating a phase error compensation amount H on the basis of the obtained update signal and a frequency error compensation amount F; and a circuit (7) for updating the frequency error compensation amount F on the basis of variations in the phase error compensation amount H, and provided with a complex multiplier (1) for complex-multiplying the carrier recovered by the carrier recovery circuit with the modulation input signal U to obtain the demodulation signal V, is provided with a means for normalizing the phase error compensation amount H updated by the phase error compensation amount update circuit (4) by an absolute value of the amount or an approximate value of the absolute value and the frequency error compensation amount updated by the frequency error compensation amount update circuit (7) by an absolute value of the amount or an approximate value of the absolute value. <P>COPYRIGHT: (C)2004,JPO |
