Patent ID: 6512739
Filing Date: 2003-01-28
Classification: H04L

Abstract:
A communication device for coupling to a communication medium and receiving therefrom an analog signal with a multi-tone communication channel modulated thereon; and the communication device comprising:a converter with an input coupled to the analog signal and an output, and the converter for converting the analog signal to discrete digital samples at the output, at a sampling rate equivalent to twice a highest frequency exhibited by the multi-tone communication channel; a downconverter with an input coupled to the output of the converter and an output, and the downconverter to downconvert the communication channel to a zero center frequency and the downconversion corresponding with a multiplication of the discrete digital samples by a sequence exp (j&pgr;n) where n is a time index; a decimator with an output and an input coupled to the output of the downconverter to decimate the discrete digital samples output therefrom to a sampling rate corresponding with twice the highest frequency exhibited after downconversion by the downconverter; a fourier transform engine coupled to the output of the decimator for converting the communication channel from a time to a frequency domain and outputting an ordered set of tones corresponding thereto; and a tone re-orderer to re-order in a reverse order the ordered set of tones from the fourier transform engine.