| 摘要 |
PROBLEM TO BE SOLVED: To improve the quality of a speech when outdoor background noise etc. is superposed, in a digital mobile wireless communication system such as a car telephone system and a mobile telephone. SOLUTION: Disclosed is a speech decoding device having a detecting means of monitoring an encoded signal encoded at a transmission side to decide whether the encoded signal is a noise section or speech section, a 1st speech decoding means of decoding the encoded signal decided to be a speech section when the detecting means decides that the encoded signal is the speech section, and a 2nd decoding means of decoding the encoded signal decided to be a noise section when the detecting means decides that the encoded signal is the noise section, the speech decoding device being characterized in that when the encoded signal of the noise section is received, the gain of a noise code book used by the 2nd decoding means is set to 0 and the gain of an adaptive code book used by the 2nd decoding means is set to 0. COPYRIGHT: (C)2006,JPO&NCIPI |
