Patent ID: 8144807

Claim:
A method of cancelling interference in a differential mode discrete multitone modulation signal received at a receiver having at least a canceller digital filter, comprising: sampling common-mode levels of the received signal; sampling differential-mode levels of the received signal; storing common-mode and differential-mode sample values from the sampling steps in a memory resource; estimating an autocorrelation of the common-mode sample values, said estimating comprising: executing a convolution of a plurality of common-mode sample values with itself; identifying a maximum value of the convolution; storing an autocorrelation vector corresponding to a number of points on each side of the identified maximum value of the convolution in a memory resource; estimating a cross-correlation of the common-mode sample values with the differential-mode sample values, comprising: executing a convolution of a plurality of common-mode sample values with a plurality of the differential-mode sample values; identifying a maximum value of the convolution; storing a cross-correlation vector corresponding to a number of points on each side of the identified maximum value of the convolution in a memory resource; estimating canceller filter coefficients from a convolution of the estimated autocorrelation and the estimated cross-correlation, comprising: creating a Toeplitz matrix from the stored autocorrelation vector; performing a convolution of at least a portion of the stored cross-correlation vector with the Toeplitz matrix to produce a weighting factor vector; storing the weighting factor vector as coefficients for the canceller digital filter; and then operating the canceller digital filter using the estimated coefficients on samples of the received differential-mode discrete multitone modulation signal.