In a multi-carrier system employing OFDM, for example DMT, an adaptive
channel equalizer is normally used, operating in the frequency domain.
The sampling clock is controlled so that the time delay between the
transmitter and the receiver is effectively eliminated. If the
information used to control the sampling clock is received from the
equalized data stream, it will introduce an ambiguity between the
operation of the channel equalizer and the mechanism used to control the
sampling clock. Operation of the equalizer can mask an increasing time
difference, between transmitter and receiver, which the sample clock
controller should be tracking. The present invention eliminates the
ambiguities in the operation of the equalizer and sample clock controller
by preventing the equalizer from accepting time differences which should
be corrected by operation of the sample clock controller.