A channel equalizer having a filter arranged to filter an input signal, the filter including a plurality of taps, each tap generating an output signal based on a coefficient, an input for receiving the coefficients and an output for outputting a filtered signal; and coefficient generating circuitry including a graduation unit arranged to receive the input signal and an error signal indicating an error in the filtered signal, to accumulate gradient values relating to each of the coefficients based on a plurality of error values of the error signal, each of the gradient values indicating a required change in one of the coefficients, and to sequentially output the gradient values; and coefficient update unit arranged to sequentially update each of the filter coefficients in turn, based on the gradient values.