Patent ID: 6963603

Claim:
An apparatus for equalizing multi-tone modulated transmissions of a modem with a transmit path and a receive path both configured to couple across a communication medium with a remote site, and the apparatus comprising: a first set of scale factors to equalize the frequency response of the transmit path of the modem and the first set of scale factors obtained before initializing communication with a remote site, and the first set of scale factors obtained by; a calibration signal source coupled to a digital portion of the transmit path to inject a calibration signal into selected tones; a frequency analyzer coupled to an analog portion of the transmit path to analyze spectral components of analog signals resulting from an injection of the calibration signal by the calibration signal source; a normalizer coupled to the frequency analyzer to determine the first set of scale factors from the spectral components analyzed by the frequency analyzer; a gain scaler for scaling each of a plurality of tones associated with initializing communications with the remote site with a corresponding one of the first set of scale factors to equalize the frequency response of the transmit path of the modem.