ECHO CANCELER DEVICE - NIPPON DENKI KK

Title:

ECHO CANCELER DEVICE

Document Type and Number:

Japanese Patent JP2778513

Kind Code:

B2

Abstract:

PURPOSE: To provide an echo canceler device capable at returning a response coefficient to a value before it is disturbed by the less storage amount of data even when the response coefficient is disturbed by double talk.
CONSTITUTION: A correction amount storage circuit 22 traces back the prescribed sample number of the correction amount of the filter coefficient of an adaptive FIR filter 12 for each sample from the latest one and stores them. Also, a reception signal storage circuit 23 stores the value of input signals until the prescribed sample number before further from the time of tracing back to exceed the tap length of the adaptive FIR filter 12. When a double talk state is detected in an erroneous estimation detection circuit 17, by subtracting the product of the value of the input signals and the stored correction amount in the past from the value of the filter coefficient set to the adaptive FIR filter 12, the value of the filter coefficient of one sample before is returned. An arithmetic operation for returning it by each sample is repeated for the required number of times and the value of the filter coefficient before it is disturbed by the double talk is returned.

Inventors:

SASADA TAISUKE

Application Number:

JP8979895A

Publication Date:

July 23, 1998

Filing Date:

April 14, 1995

Export Citation:

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