1. A modem, comprising: a) a transmitter; and b) a receiver having an equalizer which receives an input signal, an adaptive compensator, and a decision block which generates a decision related to said input signal, a difference between an output of said equalizer and a compensating signal output of said adaptive compensator providing an input for said decision block, a difference between said output of said equalizer and an output of said decision block providing an error estimation signal which is a first input to said adaptive compensator, a difference between said input to said decision block and said output of said decision block providing an error adaptation signal which is a second input to said adaptive compensator.