| 摘要 |
PURPOSE:To attach capacity to switch cord book size adaptively by performing Gain/Shape vector quantization by designating the cord book size to which a cord book vector belongs by the amplitude of an input vector. CONSTITUTION:The input vector from a terminal 1 is inputted to a reference deviation calculation circuit 2, and the reference deviation of a signal included in the vector is calculated. Corresponding to the reference deviation, the cord book size is limited to several kinds at a circuit 3. The lower limit and upper limit information of the cord book size are selected from each cord book in a cord book group 4, and are delivered to an inner product arithmetic circuit 5. At the inner product arithmetic circuit 5, the inner product of the input vector and the Shape vector in the cord book is calculated, and its output is inputted to a selection and decision circuit 6, then, information to be transmitted is decided. The information is variable length-encoded at a variable length encoder circuit 7 comprehensively. |
