| 摘要 |
PROBLEM TO BE SOLVED: To provide devices for encoding and decoding an SNR bit rate extended speech, and a method therefor. SOLUTION: This encoding device includes a basic hierarchy, a sound quality improvement hierarchy, and a multiplexer. The basic hierarchy filters an input speech signal through linear predicted encoding to generate an excitation signal corresponding to the filtered speech signal through a fixed code-book search and an adaptive code-book search. The sound quality improvement hierarchy searches a fixed code book by using a medium variable generated through the fixed code-book search in the basic hierarchy, or searches the fixed code book by using an object signal obtained by removing a signal, generated by composition filtering of the degree of contribution of the fixed code book in the basic hierarchy and a previous fixed code book, from a fixed code-book search object signal of the basic hierarchy, and the multiplexer multiplexes the signal generated in at least one sound quality improvement hierarchy with the signal generated in the basic hierarchy. COPYRIGHT: (C)2005,JPO&NCIPI
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