DIGITAL PROCESSING APPARATUS AND DIGITAL PROCESSING METHOD

摘要

In order to enhance the speed of a processing necessary for setting the factor of a filter and further maintain the accuracy of the filter, a digital processing apparatus includes: a Fourier transform unit that Fourier transforms a time domain digital signal, thereby generating N frequency domain signals; a filter unit that uses N first factors to process the frequency domain signals in the frequency domain; an inverse Fourier transform unit that transforms the frequency domain signals as processed by the filer unit to a time domain digital signal; a low accuracy factor calculation unit that uses m second factors to calculate N first A factors; a high accuracy factor calculation unit that includes a factor division unit for calculating respective ratios of N third factors to the N first A factors and that also includes a factor variable unit for calculating N first B factors varying stepwise from one to the respective ratios; a multiplication unit that multiplies the first A factors by the first B factors, thereby calculating the N first factors; and a control unit that controls the low accuracy factor calculation unit and high accuracy factor calculation unit by causing only the low accuracy factor calculation unit to operate with the first B factors being set to one and thereafter causing the high accuracy factor calculation unit to calculate the first B factors based on the third factors.

主权项

1. A digital processing apparatus comprising:
a Fourier transform unit that Fourier-transforms a time domain digital signal and generates N frequency domain signals (where N is a natural number); a filter unit that processes the frequency domain signals in a frequency domain using N first factors; an inverse Fourier transform unit that transforms the N frequency domain signals processed by the filter unit into a time domain digital signal; a low accuracy factor calculation unit that calculates N first A factors using m second factors (where N>m and m is a natural number); a high accuracy factor calculation unit including a factor division unit that calculates respective ratios of N third factors and the N first A factors and factor variable that calculates N first B factors each varying in a stepwise fashion from 1 to corresponding ratios; a multiplication unit that calculates the N first factors by multiplying the first A factor and the first B factor together; and a control unit that controls the low accuracy factor calculation unit and the high accuracy factor calculation unit in such a way that the high accuracy factor calculation unit calculates the first B factors based on the third factors after causing only the low accuracy factor calculation unit to operate with the first B factors being set to 1.