Patent ID: 8611411

Claim:
An equalizer comprising: a linear equalizer unit configured to sequentially subject a signal to be processed to linear equalization; a temporary decision unit configured to sequentially subject a signal subjected to linear equalization by the linear equalizer unit to temporary decision according to a partial response rule; a nonlinear equalizer unit implemented by a neural network and configured to derive a plurality of coefficients of a neural network using a signal subjected to temporary decision by the temporary decision unit as a teacher signal and without using a training signal, a known input in the presence of a given output, normally required for learning in a neural network, and to sequentially subject a signal subjected to linear equalization by the linear equalizer unit to nonlinear equalization based on the plurality of coefficients; and delay unit configured to delay a signal subjected to nonlinear equalization by the nonlinear equalizer unit, wherein the delay unit delays the signal for a duration commensurate with the difference between processing delay in the temporary decision unit and processing delay in the nonlinear equalizer unit, the nonlinear equalizer unit derives the plurality of coefficients based on the difference between a signal delayed by the delay unit and a signal subjected to temporary decision by the temporary decision unit, and wherein the nonlinear equalizer unit derives a plurality of new coefficients when the difference between the signal delayed by the delay unit and the signal subjected to temporary decision by the temporary decision unit grows larger than a threshold value.