| 摘要 |
PROBLEM TO BE SOLVED: To enable accurate quantization with a relatively smaller number of code vectors when transformation is performed in frequency domain for vector-quantization. SOLUTION: Frequency domain coefficients of an input acoustic signal are divided into small vectors, and corresponding weight coefficients are also divided similarly, and by using these corresponding ones, optimal code vectors are searched from a code book 39. In this case, the presence or absence of a minute structure is judged in the spectrum of the input acoustic signal, and if the minute structure exists, approximately a third of the absolute values among the element are left in descending order to the code vectors taken out of the code book 39 and are deformed so that the amplitudes become large by defining the other elements as zero, while, if the minute structure does not exist, they are used without performing the deformation. |
