| 摘要 |
PURPOSE: To minimize the deterioration in arithmetic precision by obtaining a filter response depending on an input signal before a preceding time block independently of a filter response with respect to an input signal of a current time block and obtaining a filter output through the synthesis of the response of the both. CONSTITUTION: An input signal Xk(i) for a k-th time block is multiplied with a normalizing coefficient Ak obtained by a normalizing coefficient calculation section 9 and the result is given to a 1st filter section 10. Then the input signal Xk(i)×Ak to the filter section 10 is filtered to be a 1st filter output K1k and it is multiplied with an inverse normalizing coefficient 1/Ak being a reciprocal of the normalizing coefficient Ak obtained by an inverse normalizing coefficient calculation section 11 to be a 1st inverse normalizing filter output Y1k(i)/Ak. Furthermore, an output Y2k(i) of a 2nd filter section 12 is multiplied with an inverse normalizing coefficient 1/(Ak-1) for a (k-1)th time block stored in a preceding time block inverse normalizing coefficient storage section 13 to be a 2nd filter output Y2k(i)/(Ak-1) and it is added to the 1st filter output Y1k(i) and the sum is outputted via an output buffer 14.
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