Patent ID: 7684359

Claim:
An OFDM receiving apparatus, comprising: an offset estimating unit which estimates offset of a sampling frequency if the receiving apparatus is in a tracking mode, the sampling frequency being used for a Fast Fourier Transform (FFT) of an Orthogonal Frequency Division Multiplexing (OFDM) signal; a channel estimating unit for estimating a channel delay profile using a channel impulse response of the OFDM signal; and an offset compensating unit for compensating for an influence due to the offset by using a duration of an FFT interval transition due to the estimated offset, a profile duration of the estimated channel delay profile and a duration of a guard interval included in an OFDM symbol to determine a location of the channel delay profile in the guard interval, wherein the offset compensating unit adjusts the channel delay profile to locate the center of the channel delay profile within the guard interval, if the profile duration is equal to or less than a predetermined reference duration, and wherein the offset compensating unit adjusts the channel delay profile to locate the center of the channel delay profile at a predetermined distance from the center of the guard interval if the profile duration is greater than the predetermined reference duration, and a sum of the profile duration and the FFT interval transition duration is equal to or less than the guard interval duration.