Patent ID: 8358683

Claim:
A channel equalizer arranged to receive a received signal from a data signal encoded by a plurality of amplitude levels, the channel equalizer comprising: a filter comprising a plurality of taps, each tap generating an output signal based on a coefficient, an input for receiving an error signal for adapting said coefficients, and an output for outputting a filtered signal; and blind error generation circuitry arranged to generate said error signal, the blind error generation circuitry comprising: error estimating circuitry arranged to estimate the error of said filtered signal based on maximum likelihood by determining a probability for each of the plurality of amplitude levels encoding the data signal, given the filtered signal; and adding circuitry coupled to said error estimating circuitry and to the output of said filter and arranged to add at least part of said filtered signal to the error estimated by said error estimating circuitry to generate said error signal; wherein the error estimating circuitry is arranged to estimate the error of said filtered signal based on the following formula: e ( t )=( y−a 1)* p ( s=a 1 |y )+ . . . +( y−aN )* p ( s=aN|y ) where there are N amplitude levels, a1 being a first level and aN being a final level, where y is the filtered signal, s is the data signal, and p(s=aN|y) is a probability that s is equal to level aN given the filtered signal y.