Patent ID: 7260144

Claim:
An improved equalization system for DMT based modem receiver comprising: a time domain equalizer for processing samples from an analog front end; means for transferring samples of every DMT frame from said time domain equalizer to a Fast Fourier Transform (FFT) buffer; means for computing differences of time domain samples for every frame into the FFT buffer and saving the results in the FFT buffer; a first FFT for calculating the first FFT and saving the results in said FFT buffer so that at each DMT frame, after a difference and FFT operation, the FFT buffer contains the first FFT and v−1 time domain sample differences; a sliding FFT that for each tone reads the first FFT result and v−1 FFTs from FFT buffer and recursively computes the rest of v−1 FFTs for the particular tone; and an equalizer responsive to the computed sliding FFT for computing equalizer outputs.