| 摘要 |
An auto-correlation calculation circuit (320,330) calculates an auto-correlation of an impulse response signal of a weighting function for the corresponding sub-interval of a plurality of sub-intervals of an input signal vector. A weighted cross-correlation calculation circuit (365) calculates a weighted cross-correlation of the weighted input signal vector and the weighted codevector having a length equal to a code length of the input signal vector, by using the input signal vector, a plurality of codevectors and a plurality of impulse responses. A weighted auto-correlation calculation circuit (360) calculates an auto-correlation of the weighted codevectors, by using the respective auto-correlations of the plurality of impulse responses, of the plurality of codevectors and of the cross-correlations. A distance between the input signal vector and the codevector is calculated, by using the cross-correlations of the weighted input signal vector and weighted codevectors, and the auto-correlation of the weighted codevector, and an index of a codevector corresponding to the minimum distance is obtained by a inspection circuit (370).
|
