| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect a clock error stably with high precision. <P>SOLUTION: In a receiving apparatus which demodulates a received OFDM signal using a synchronizing clock, a correlation signal z[t] based on a guard interval correlation method is calculated. A temporal position where the correlation value becomes maximum in each symbol term is detected as a feature position (P<SB POS="POST">A</SB>[i-1], P<SB POS="POST">A</SB>[i]). Further, thresholds TH<SB POS="POST">C</SB>[i] and TH<SB POS="POST">B</SB>[i] are set using a peak value V<SB POS="POST">PEAK</SB>[i-1] of the symbol term S<SB POS="POST">P</SB>[i-1] and temporal positions where the correlation values corresponds to the thresholds TH<SB POS="POST">B</SB>[i] and TH<SB POS="POST">C</SB>[i] in a current symbol term are detected as feature positions P<SB POS="POST">B</SB>[i] and P<SB POS="POST">C</SB>[i]. Three reference positions corresponding to the three feature positions in a reference symbol term preceding to the current symbol term S<SB POS="POST">P</SB>[i] are detected and a clock error is calculated from a position difference between the three reference positions and the three feature positions in the current symbol term S<SB POS="POST">P</SB>[i]. <P>COPYRIGHT: (C)2012,JPO&INPIT |
