Patent ID: 8396144

Claim:
A method, comprising: receiving OFDM (Orthogonal Frequency Division Multiplexing) symbols over a communications channel, wherein a guard interval of length Tg is interposed between the OFDM symbols; demodulating the OFDM symbols by discrete Fourier transforming N consecutive samples, where N is an integer, starting at a specified trigger point; calculating a channel frequency response; adjusting the trigger point for performing the discrete Fourier transform by: 1) calculating samples of a channel impulse response by inverse Fourier transforming the channel frequency response, 2) estimating a measure of the intersymbol interference that occurs in the communications channel based upon the magnitudes of samples of the channel impulse response above a specified threshold and their relation to a time origin of the channel impulse response that represents the trigger point, and 3) adjusting the time origin of the channel impulse response so as to minimize the estimated intersymbol interference and then adjusting the trigger point for demodulation of subsequent OFDM symbols in the same manner.