Title:
エコーキャンセラのトレーニングを制御する通信システム及び回線交換システム
Document Type and Number:
Japanese Patent JP4272849
Kind Code:
B2
Abstract:
A communication system being made up of a two-wire/four-wire hybrid circuit, an echo canceller, and a control device and having functions of forming a plurality of communication paths and changing communication paths is provided which is capable of ensuring high speech quality by suppressing and canceling an echo occurring in telephone speech after establishment of path connection. The communication system also includes a training signal source to feed a training signal to the echo canceller, a switching circuit to do switching of a signal to be fed to the echo canceller between an ordinary signal and the training signal, and a control device to exert control on path connection and path changing and to feed the training signal to the switching circuit to make a training signal be fed from the training signal source to the echo canceller and to have the echo canceller converge its training operation.
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Inventors:
Kazuhiko Koyama
Kazuya Suzuki
Kazuya Suzuki
Application Number:
JP2002173259A
Publication Date:
June 03, 2009
Filing Date:
June 13, 2002
Export Citation:
Assignee:
NEC Infrontia Co., Ltd.
International Classes:
H04Q3/42; H04B3/23
Domestic Patent References:
| JP4207794A | ||||
| JP3188718A | ||||
| JP7303069A | ||||
| JP61225995A | ||||
| JP2164163A | ||||
| JP200186225A | ||||
| JP6218123A |
Attorney, Agent or Firm:
Takao Maruyama