| 摘要 |
PROBLEM TO BE SOLVED: To precisely detect a frequency error while avoiding the increase of a circuit scale. SOLUTION: A frequency error detection circuit for receiving an OFDM signal and detecting the frequency error between its carrier frequency and a local oscillation frequency is provided with a storage part and a calculation part. The storage part stores the argument of a complex number belonging to one of the areas obtained by radially dividing a complex plane with its origin as the center and the tangent value. When a complex number obtained by performing complex multiplication of the complex conjugate of a signal obtained by delaying the prescribed part of the OFDM signal by a period corresponding to one symbol with the local oscillation frequency and the prescribed part belongs to the one area, the calculation part specifies the argument of a complex number based on the stored content of the storage part. When the complex number belongs to the other area, the calculation part specifies an angle fixed previously to the other area as the argument of the complex number. The calculation part calculates the frequency error based on the specified result. COPYRIGHT: (C)2005,JPO&NCIPI
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