Patent ID: 7028063

Claim:
An apparatus for processing input sample sets of at least one discrete multi-tone (DMT) modulated communication channel, and the apparatus comprising: an input memory storing each input sample set as a two-dimensional array of rows and columns of samples; an output memory storing two-dimensional arrays of rows and columns of coefficients resulting from a corresponding one of a time-to-frequency domain transformation and a frequency-to-time domain transformation of each input sample set; and a two-dimensional Fourier transform circuit coupled between the input and output memory to perform the corresponding transformation of the input sample set and having: row transform components including a Radix-R butterfly having “R” inputs and “R” output nodes; and the row transform components generating partial row transforms limited to solutions to a single unsolved one of the “R” output nodes of the Radix-R butterfly on each of the “R” iterations through ordered sets of samples from each input sample set; and column transform components coupled to the row transform components and configured to generate complete column transforms from the partial row transforms generated by the row transform components prior to a completion of the “R” iterations through each input sample set by the row transform components; thereby to reduce an interval required to transform each successive input sample set.