| 摘要 |
PURPOSE:To avoid the reduction in the essential code book size of a next stage caused by the quantization result of the pre-stage in the divided vector quantization system of line spectrum pair(LSP) coefficients. CONSTITUTION:An input vector X of a line spectrum pair, which has a distribution with a prescribed width, is divided into plural spectra which are distributed with a smaller width and each divided vector X1 to XN is independently vector quantized by quantizers 2-1 to 2-N in a divided vector quantization system. In this system, a conversion is made to the vector quantization result of the pre-stage so that all coded vectors stored in the code book of the next stage vector quantizer satisfy the stable condition of the line spectrum pair and then the vector quantization of this stage is performed. |
