VECTOR QUANTIZATION DEVICE, VECTOR INVERSE QUANTIZATION DEVICE, AND METHOD THEREOF

摘要

Disclosed are a vector quantization device and others capable of adaptively adjusting a vector space of a code vector for quantization of a second stage by using a quantization result of a first stage and improving the quantization accuracy. In the device, the first quantization unit (101) performs quantization of an LSP vector; a quantization residual difference generation unit (102) acquires a residual difference between the LSP vector and the first quantization vector obtained by the first quantization unit (101) as a quantization residual difference vector; an addition factor selection unit (103) selects one of the addition factor code vectors in an addition factor codebook as an addition factor vector according to the first code obtained by the first quantization unit (101); an addition residual difference generation unit (104) acquires a residual difference between the quantization residual difference vector and the addition factor vector as an addition residual vector; and a second quantization unit (105) performs quantization of the addition residual difference vector.