Patent ID: 7778134

Claim:
A waveform equalization control device comprising: a waveform equalizer that has a filter provided with a plurality of taps, updates a tap coefficient of each of the plurality of taps in accordance with a tap coefficient signal inputted thereto, causes the plurality of taps to respectively receive a plurality of values sampled at different time points from an input signal, performs waveform equalization with respect to the input signal, and outputs the signal after the waveform equalization; a first equalization target value generation unit for determining a first equalization target value based on the signal after the waveform equalization outputted from the waveform equalizer and outputting the first equalization target value; an error estimation unit for obtaining an error between the first equalization target value and the signal after the waveform equalization and outputting the error as an error signal; and a coefficient update unit for calculating an amount of updating the coefficient of each of the taps of the filter of the waveform equalizer based on the error signal and on the input value to each of the taps and outputting the amount of updating the coefficient as the tap coefficient signal, wherein the first equalization target value generation unit obtains sign signals each showing whether the signal after the waveform equalization has a positive value or a negative value for first, second, third, fourth, and fifth time points which are successively different by intervals at which the input signal is sampled, calculates a first total sum which is a sum of respective results of multiplying the sign signals for the first to fifth time points by θ, β, α, β, and θ (where each of α, β, and θ is a predetermined real number), and determines a value corresponding to the first total sum as the first equalization target value.