Patent ID: 7031379

Claim:
A method of training a time domain equalizer in a receiving modem, comprising the steps of: receiving a training signal; regenerating the training signal in the receiving modem; operating a digital circuit in the receiving modem to derive coefficients for a time-domain equalizer digital filter from the received and regenerated training signals, by performing a minimization process constrained by a spectral flatness term in the frequency domain of the equalizer characteristic; and storing a filter vector based on the derived coefficients, for use in a time-domain equalizer digital filter, wherein the operating step comprises: deriving correlation matrices from the received and regenerated training signals; deriving eigenvectors and eigenvalues for a combination of the correlation matrices; evaluating a cost function including a mean squared error term and a weighted spectral flatness term, the evaluating being performed using the derived eigenvectors and eigenvalues, over multiple trial values of a weighting constant; selecting a value of the weighting constant that provides a minimum value of the cost function; and then deriving an optimal filter vector using the selected weighting constant value.