| 摘要 |
PURPOSE:To reduce the size and price of an arithmetic circuit and to enable highly precise quantization by performing arithmetic processing for searching a code book with high precision by using a point type arithmetic circuit. CONSTITUTION:An LPC synthesizing filter 47 performs filter arithmetic for plural code vectors stored in a code book 45 and the arithmetic for searching the code book 45 for the code vector having the minimum squaring error between the obtained synthesized voice vector and an input vector is performed. At this time, the calculation result of correlation between the composite voice vector obtained by the filter arithmetic and the input signal vector and the sum of the squares of the elements of synthesized voice vectors obtained by the filter arithmetic are normalized by normalization parts 57 and 58 and a squaring error calculation part 49 calculates the squaring error from the normalized correlation calculation result and sum of squares. |
