ECHO CANCELER SYSTEM

Japanese Patent JP2794999

B2

PURPOSE: To obtain the echo canceller system having a PCM interface having excellent echo cancelling capability and operated stably even in a line having quantization noise or the like caused by nonlinear processing of a PCM line.
CONSTITUTION: This canceller is provided with a main pseudo echo generator 21, a sub pseudo echo generator 22 and an output of the main pseudo echo generator 21 is provided newly with a nonlinear quantization processing unit 27 to cancel quantization noise caused in a PCM line. Through the constitution above, a pseudo echo output obtained through a main pseudo echo generator 21 and a nonlinear quantizer processing unit 27 is subtracted from the echo by a main subtractor 25 to obtain a main residual echo and the result is outputted from a terminal 8 as an output signal. Then a pseudo echo output from the sub pseudo echo generator 22 is subtracted from the main pseudo echo to obtain a sub residual echo. When the sub residual echo is smaller than the main residual echo, the H register addition processing to add the content of the H register in the sub pseudo echo generator 22 to the content of the H register in the main pseudo echo generator 21 is implemented and then the sub H register 22 is reset.

JP2953954	DOUBLE TALK DETECTOR AND ECHO CANCELER
JPH0638589	[Title of Invention] Eco-Cancera
JPH053459	VOICE DECODER

SUGAYA FUMIAKI
HACHITSUKA YOTARO

JP22861691A

September 10, 1998

August 14, 1991

Click for automatic bibliography generation  

KOKUSAI DENSHIN DENWA KK

H04B3/23; H04B14/04; H04M9/08; (IPC1-7): H04B3/23; H04B14/04

JP5327559A
JP4286218A
JP4213927A

１９９１年電子情報通信学会春季全国大会講演論文集〔分冊〕（１９９１−３−１５）Ｐ．３・３１０
１９９１年電子情報通信学会春季全国大会講演論文集〔分冊〕（１９９１−８−１５）Ｐ．３・２４０

Keiichi Yamamoto

Previous Patent: MORPHEME ANALYSIS DEVICE AND PARAGRAPH DICTIONARY PREPARING DEVICE

Next Patent: ALPHA-(P-(DIETHYLAMINO)PHENYL)-N-(ALKYLPHENYL)NITRONE COMPOUND AND CONTRAST ENHANCED MATERIAL