A method and an apparatus for a channel estimator comprising a plurality of distinct
filters each of which has a set of different coefficients and each of which is
selectively coupled to the input and output of the channel estimator. The channel
estimator further comprises a switching circuit that receives an error signal and
switches to one of the plurality of filters based on the value of the error signal
relative to an established threshold. The error signal is from a decoder coupled
to a communication channel whose response is being estimated by the apparatus and
method of the present invention.