JPS5789337A - Echo erasing device - Google Patents
Echo erasing deviceInfo
- Publication number
- JPS5789337A JPS5789337A JP16563180A JP16563180A JPS5789337A JP S5789337 A JPS5789337 A JP S5789337A JP 16563180 A JP16563180 A JP 16563180A JP 16563180 A JP16563180 A JP 16563180A JP S5789337 A JPS5789337 A JP S5789337A
- Authority
- JP
- Japan
- Prior art keywords
- level
- echo
- signal
- output
- measuring circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/02—Details
- H04B3/20—Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other
- H04B3/23—Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other using a replica of transmitted signal in the time domain, e.g. echo cancellers
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
PURPOSE:To prevent the lowering of the quantity of echo erase, by detecting rapidly the overlap speech state even for a low overlap signal level and a low echo signal level by detecting the level of the transmission-side signal in the output level. CONSTITUTION:The receiving-side signal has the level measured by a receiving- side signal level measuring circuit 8, and the erase residual echo in the transmission output side of a subtracting circuit 6 of an echo erasing part 5 has the level measured by a erase residual signal level measuring circuit 9 as a transmission-side signal. On the basis of outputs of both level measuring circuits 8 and 9, the sum of echo loss and cancellation is obtained by an attenuation quantity measuring circuit 10. The attenuation quantity level from the attenuation quantity measuring circuit 10 and the receiving-side output signal level are inputted to an operation circuit 11 for an erase residual echo level estimated value to obtain the estimated value of the erase residual echo level. This estimated value is compared with the output of the erase residual signal level measuring circuit 9 by a comparing circit 12, and an approximate echo signal synthesizing circuit 7 is controlled by the comparison output.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP16563180A JPS5789337A (en) | 1980-11-25 | 1980-11-25 | Echo erasing device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP16563180A JPS5789337A (en) | 1980-11-25 | 1980-11-25 | Echo erasing device |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5789337A true JPS5789337A (en) | 1982-06-03 |
JPH0131731B2 JPH0131731B2 (en) | 1989-06-27 |
Family
ID=15816027
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP16563180A Granted JPS5789337A (en) | 1980-11-25 | 1980-11-25 | Echo erasing device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5789337A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5949027A (en) * | 1982-09-14 | 1984-03-21 | Fujitsu Ltd | Echo canceller controlling system |
-
1980
- 1980-11-25 JP JP16563180A patent/JPS5789337A/en active Granted
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5949027A (en) * | 1982-09-14 | 1984-03-21 | Fujitsu Ltd | Echo canceller controlling system |
Also Published As
Publication number | Publication date |
---|---|
JPH0131731B2 (en) | 1989-06-27 |
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