Adaptive
equalization methods and adaptive equalizers used with precoded systems dominated by
intersymbol interference (ISI) monitor the output of a DFE and compare it to a reference for updating a precoder in response to the comparison. To accomplish this, an
adaptive equalizer includes a
feed forward equalizer receiving a
signal from a
communication channel, the
feed forward equalizer equalizing variations in pre-cursor
intersymbol interference resulting from changes in characteristics of the channel and providing an output
signal to an error correction decoder, a
decision circuit, coupled to the
feed forward equalizer, for generating error vectors in response to the output
signal of the
feed forward equalizer and a decision feedback equalizer, coupled to the
decision circuit, the decision feedback equalizer monitoring the pre-cursor
intersymbol interference of the channel, determining when the
transmitter coefficients to the precoder warrant updating, and generating a signal indicating that an update to the
transmitter coefficients to the precoder is warranted. The
adaptive equalizer farther includes a comparison circuit, the comparison circuit receiving an output from the decision feedback equalizer and comparing the output from the decision feedback equalizer to a reference, the comparison circuit generating the signal indicating that an update to the
transmitter coefficients to the precoder is warranted in response to the comparison.