Patent ID: 6993093

Claim:
An OFDM receiving apparatus comprising: delay equalizing means including adding means to which an OFDM-modulated signal including a direct wave and a delayed wave is input and feedback means for delaying the direct wave output from the adding means and for negatively feeding back to the adding means the delayed direct wave so as to remove the delayed wave; autocorrelation detecting means for detecting the amplitude of the direct wave and the amplitude of the delayed wave and for detecting the time at which each of the amplitudes becomes the local maximum; and a plurality of path correlation detecting means for delaying the input OFDM-modulated signal by different periods to detect a path correlation value indicating a phase difference between the direct wave and the delayed wave, wherein said delay equalizing means further includes delay time calculating means for calculating a plurality of delay times which differ from each other by short time periods based on the times at which the amplitudes of the direct wave and the delayed wave become the local maximum, the plurality of delay times including the delay time of the delayed wave with respect to the direct wave, so as to delay the OFDM-modulated signal input to said plurality of path correlation detecting means by the plurality of delay times, and said feedback means causes the amplitude and phase of the negatively fed back direct wave to coincide with the amplitude and phase of the delayed wave input to the adding means based on the largest path correlation value of the path correlation values so as to delay the negatively fed back direct wave by a designated delay time based on which the largest path correlation value is determined.