| 摘要 |
PROBLEM TO BE SOLVED: To switch code books formed by use of respective learning data for a plurality of signals differed in property to improve the performance of quantization. SOLUTION: The representative vectors or reversed quantized outputs from vector quantizers 511, 512 having code books CBA, CBB, are transmitted to subtracters 513, 514, respectively, to determine the differences with the original input signal, and each error portion is transmitted to a comparator 515. In the comparator 515, each error portion is compared, and the index which is the quantized output from the vector quantizer 511, 512 having the smaller error is switched and selected by a change-over switch 516, and transmitted to an output terminal 502. The quantization is performed in sub-frame unit, and the switching in frame unit. |
