Title:
ECHO CANCELER AND ECHO CANCELING METHOD
Document Type and Number:
Japanese Patent JP2940822
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To absorb learning fluctuations due to noise by calculating a filter coefficient for a back up by using a prescribed learning process.
SOLUTION: When a changeover switch 23 is connected to a contact 'a', a signal in which a 1st dummy echo signal that is produced by a first echo canceler part 21 is eliminated from an input signal is outputted. The production of the first dummy echo signal uses a filter coefficient that is stored in a coefficient memory 32. Next, when count value reaches a prescribed count in one time learning which is performed by a filter coefficient learning part 31 in the part 21, a backup coefficient is calculated and backup to back up memory 41 in a second echo canceler part is performed. Next, when the switch 23 is connected to a contact 'b', a signal in which a second dummy echo signal produced by the part 22 is eliminated from an input signal is outputted. At this time, the backup coefficient in the memory 41 is used.
Inventors:
OKUDA KOZO
Application Number:
JP26003898A
Publication Date:
August 25, 1999
Filing Date:
September 14, 1998
Export Citation:
Assignee:
SANYO DENKI KK
International Classes:
H03H21/00; H03H17/02; H04B3/23; H04M1/60; (IPC1-7): H04B3/23; H03H17/02; H03H21/00; H04M1/60
Domestic Patent References:
| JP8265222A | ||||
| JP8288889A | ||||
| JP7193528A | ||||
| JP5206896A | ||||
| JP1126839A |
Attorney, Agent or Firm:
Koji Yasutomi (1 person outside)