发明名称 |
Voice-coding-and-transmission system |
摘要 |
In a voice coding-and-transmission system using a differential coding, a degradation of voice quality caused by a silent period transmission network and an ATM network is prevented without improving a silent-period elimination transmission network and existing transmission networks such as a STM network. In a relay node (104), an encoder (114) codes a voice signal from a decoder (108) again for a transient period immediately after a voice is started, and a transmission node (100) and a reception node (102) are tandem-connected. The encoder (114) and a decoder (122) at a reception node (102) are given respectively same reference values of a differential processing by memories (118, 128) when the voice is started, thereby preventing an abnormal sound generation due to a mismatch of inner statuses thereof when the voice is started. During the transient period, the internal statuses of an encoder (106) at a reception node (100) and the decoder (122) are closed each other. After the transient period is elapsed, switching a switch in a silent-period eliminator (112) to a digital-one-link, thereby preventing the degradation of the voice duality caused by quantization errors. <IMAGE>
|
申请公布号 |
EP1453231(A1) |
申请公布日期 |
2004.09.01 |
申请号 |
EP20040013247 |
申请日期 |
1997.03.27 |
申请人 |
MITSUBISHI DENKI KABUSHIKI KAISHA |
发明人 |
YAJIMA, HISASHI;KAWANO, NORIAKI;NAITO, YUSHI;SUZUKI, SHIGEAKI |
分类号 |
G10L19/04;G10L;G10L15/00;G10L19/00;G10L19/12;G10L19/14;H03M3/04;H03M7/30;H04B1/66;H04J3/17;H04L12/28;H04Q3/00;(IPC1-7):H04J3/17 |
主分类号 |
G10L19/04 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|