| 摘要 |
<p>An apparatus and a method for estimating frequency offset are provided to reduce cost and the number of hardware by lowering calculation complexity according to the reduction of estimation values. An apparatus for estimating frequency offset includes an FFT(Fast Fourier Transform) unit(100), first and second pilot information units(110,140), first and second partial correlators(120,150), and first and second maximum likelihood selectors(130,160). The FFT unit converts received signals from time domain to frequency domain based on an FFT scheme. The first pilot information unit forms an aggregation of pilot symbols, which are positioned at odd numbered sub-carriers, among whole symbols. The first partial correlator calculates correlation values between the pilot symbols and successive two OFDM(Orthogonal Frequency Division Multiple) reception signals. The first maximum likelihood selector obtains real values of the correlation values and selects frequency offset candidate values. The second pilot information unit forms an aggregation of pilot symbols, which are positioned at even numbered sub-carriers, among whole symbols. The second partial correlator calculates correlation values between the pilot symbols of the second pilot information unit and successive two OFDM reception signals, and adds the calculated correlation values with a correlation value calculated in the first partial correlator. The second maximum likelihood selector selects a final frequency offset by applying a maximum likelihood scheme using a correlation value outputted from the second partial correlator.</p> |
