| 摘要 |
PROBLEM TO BE SOLVED: To obtain a voice encoding device and a decoding device that can transmit a voice band data signal such as a modem signal at high speed and is capable of seamless mode switching to and from a voice signal transmission mode. SOLUTION: An encoder which uses the CELP system selects a 1st algebraic code book 16 in voice signal transmission and a 2nd algebraic code book 18 in voice band data signal transmission according to the identification result of an input signal outputted by a signal identification part 11. The output of the 2nd algebraic code book 18 is converted by a down sampling part 19 to the same sampling frequency with the 1st algebraic code book 16 to generate a composite signal. COPYRIGHT: (C)2004,JPO
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