| 摘要 |
Tap coefficients of an FIR filter are prevented from converging to a wrong value. A waveform equalizing device, which equalizes a waveform of an input signal and outputs its result as an output signal, is provided with an FIR filter for carrying out a convolution operation between the input signal and a plurality of its tap coefficients, an IIR filter for carrying out a convolution operation between the output signal and a plurality of its tap coefficients, an adding unit for adding the operation result of the FIR filter to that of the IIR filter, an error detecting unit for detecting an error of the output signal, and a tap coefficient updating unit for updating the tap coefficients of the FIR filter and the IIR filter in accordance with the error. The tap coefficient updating unit makes a step size for updating the tap coefficients of the FIR filter smaller than a step size for updating the tap coefficients of the IIR filter during a period from the operation commencement time of the waveform equalizing drive unit until a predetermined condition is satisfied.
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