Patent ID: 8594210

Claim:
A method of an Orthogonal Frequency Division Multiplexing—OFDM—receiver for positioning a fast Fourier transform—FFT—window, comprising: determining a position of the FFT-window in relation to one or more OFDM-symbols of a received OFDM-signal; using the position of the FFT-window to obtain a first OFDM-symbol from the received OFDM-signal; applying an FFT to the first OFDM-symbol to produce an FFT-output signal; determining a frequency dependent phase rotation component of the FFT-output signal based on the FFT-output signal; removing the determined frequency dependent phase rotation component from the FFT-output signal to obtain a compensated FFT-output signal; calculating a delay spread estimate using at least one of the FFT-output signal and the compensated FFT-output signal; and adjusting the position of the FFT-window based on at least the determined frequency dependent phase rotation component and the calculated delay spread estimate.