SE8102048L - echo cancellation - Google Patents
echo cancellationInfo
- Publication number
- SE8102048L SE8102048L SE8102048A SE8102048A SE8102048L SE 8102048 L SE8102048 L SE 8102048L SE 8102048 A SE8102048 A SE 8102048A SE 8102048 A SE8102048 A SE 8102048A SE 8102048 L SE8102048 L SE 8102048L
- Authority
- SE
- Sweden
- Prior art keywords
- echo
- signal
- component
- response
- compensated signal
- Prior art date
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)
- Bidirectional Digital Transmission (AREA)
Abstract
A full-duplex, two-wire Nyquist sampled data communication system includes an adaptive echo canceller (24) at each terminal (e.g., 10'). The echo canceller generates a replica (zm) of the echo component of each sample (rM) of the incoming signal. The replica and the sample are subtractively combined to provide an echo compensated signal (SM). During intervals of simultaneous transmission and reception, i.e., double talk, the echo compensated signal may contain not only an uncancelled echo component but also a far-end data component. An adaptation error signal generator (80), operating in response to a stream of recovered data symbols (e.g., ân), estimates and removes the far-end data component from the echo compensated signal and, in response to the difference, generates an adaptation error signal ( gamma EM-D). This signal is applied as an error signal to the echo canceller. This allows the echo canceller to adapt its set of tap coefficients in response to the uncancelled echo component present in the echo compensated signal. Thus, stable and accurate echo cancellation results even during a double-talk interval. <IMAGE>
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US13866380A | 1980-04-09 | 1980-04-09 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| SE8102048L true SE8102048L (en) | 1981-10-10 |
| SE447437B SE447437B (en) | 1986-11-10 |
Family
ID=22483068
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| SE8102048A SE447437B (en) | 1980-04-09 | 1981-03-31 | SET AND DEVICE FOR ECO-ELIMINATION |
Country Status (13)
| Country | Link |
|---|---|
| JP (1) | JPS56157152A (en) |
| AU (1) | AU540883B2 (en) |
| CA (1) | CA1175521A (en) |
| CH (1) | CH651980A5 (en) |
| DE (1) | DE3113394C2 (en) |
| DK (1) | DK149681A (en) |
| ES (1) | ES501182A0 (en) |
| FR (1) | FR2480534B1 (en) |
| GB (1) | GB2075313B (en) |
| IL (1) | IL62600A (en) |
| IT (1) | IT1137680B (en) |
| NL (1) | NL8101741A (en) |
| SE (1) | SE447437B (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2534427A1 (en) * | 1982-10-11 | 1984-04-13 | Trt Telecom Radio Electr | ECHO CANCER FOR DATA SIGNAL IN BASE STRIP |
| US4894820A (en) * | 1987-03-24 | 1990-01-16 | Oki Electric Industry Co., Ltd. | Double-talk detection in an echo canceller |
| DE68924261T2 (en) * | 1989-06-22 | 1996-03-21 | Ibm | Echo cancellation device with adaptation of the echo cancellation coefficients during full duplex transmission. |
| US6895086B2 (en) | 2001-11-13 | 2005-05-17 | Inmate Telephone, Inc. | 3-Way call detection system and method |
| CA2534767A1 (en) | 2003-08-05 | 2005-03-17 | Inmate Telephone, Inc. | Three-way call detection using steganography |
| US7813497B2 (en) | 2004-01-29 | 2010-10-12 | St-Ericsson Sa | Echo canceller with interference-level controlled step size |
| US8542802B2 (en) | 2007-02-15 | 2013-09-24 | Global Tel*Link Corporation | System and method for three-way call detection |
| US20080201158A1 (en) | 2007-02-15 | 2008-08-21 | Johnson Mark D | System and method for visitation management in a controlled-access environment |
| US9225838B2 (en) | 2009-02-12 | 2015-12-29 | Value-Added Communications, Inc. | System and method for detecting three-way call circumvention attempts |
| US8630726B2 (en) | 2009-02-12 | 2014-01-14 | Value-Added Communications, Inc. | System and method for detecting three-way call circumvention attempts |
| US10572961B2 (en) | 2016-03-15 | 2020-02-25 | Global Tel*Link Corporation | Detection and prevention of inmate to inmate message relay |
| US9609121B1 (en) | 2016-04-07 | 2017-03-28 | Global Tel*Link Corporation | System and method for third party monitoring of voice and video calls |
| US10027797B1 (en) | 2017-05-10 | 2018-07-17 | Global Tel*Link Corporation | Alarm control for inmate call monitoring |
| US10225396B2 (en) | 2017-05-18 | 2019-03-05 | Global Tel*Link Corporation | Third party monitoring of a activity within a monitoring platform |
| US10860786B2 (en) | 2017-06-01 | 2020-12-08 | Global Tel*Link Corporation | System and method for analyzing and investigating communication data from a controlled environment |
| US9930088B1 (en) | 2017-06-22 | 2018-03-27 | Global Tel*Link Corporation | Utilizing VoIP codec negotiation during a controlled environment call |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3499999A (en) * | 1966-10-31 | 1970-03-10 | Bell Telephone Labor Inc | Closed loop adaptive echo canceller using generalized filter networks |
| US4087654A (en) * | 1975-11-28 | 1978-05-02 | Bell Telephone Laboratories, Incorporated | Echo canceller for two-wire full duplex data transmission |
| US4074086A (en) * | 1976-09-07 | 1978-02-14 | Bell Telephone Laboratories, Incorporated | Joint adaptive echo canceller and equalizer for two-wire full-duplex data transmission |
| SE416367B (en) * | 1976-09-07 | 1980-12-15 | Western Electric Co | EKOELIMINERINGSANORDNING |
| JPS5582551A (en) * | 1978-12-15 | 1980-06-21 | Nec Corp | Echo cancel unit for two line type duplex data communication modem |
-
1981
- 1981-03-17 CA CA000373185A patent/CA1175521A/en not_active Expired
- 1981-03-25 AU AU68722/81A patent/AU540883B2/en not_active Ceased
- 1981-03-31 SE SE8102048A patent/SE447437B/en not_active IP Right Cessation
- 1981-04-02 DK DK149681A patent/DK149681A/en not_active IP Right Cessation
- 1981-04-03 DE DE3113394A patent/DE3113394C2/en not_active Expired
- 1981-04-06 GB GB8110703A patent/GB2075313B/en not_active Expired
- 1981-04-07 IL IL62600A patent/IL62600A/en unknown
- 1981-04-07 FR FR8106951A patent/FR2480534B1/en not_active Expired
- 1981-04-08 ES ES501182A patent/ES501182A0/en active Granted
- 1981-04-08 NL NL8101741A patent/NL8101741A/en not_active Application Discontinuation
- 1981-04-08 CH CH2375/81A patent/CH651980A5/en not_active IP Right Cessation
- 1981-04-08 IT IT20998/81A patent/IT1137680B/en active
- 1981-04-09 JP JP5377381A patent/JPS56157152A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| FR2480534A1 (en) | 1981-10-16 |
| DE3113394A1 (en) | 1982-05-06 |
| GB2075313A (en) | 1981-11-11 |
| AU6872281A (en) | 1981-10-15 |
| GB2075313B (en) | 1984-05-02 |
| DK149681A (en) | 1981-10-10 |
| JPS56157152A (en) | 1981-12-04 |
| AU540883B2 (en) | 1984-12-06 |
| IT8120998A0 (en) | 1981-04-08 |
| CH651980A5 (en) | 1985-10-15 |
| ES8205088A1 (en) | 1982-06-16 |
| IL62600A (en) | 1983-11-30 |
| DE3113394C2 (en) | 1985-11-21 |
| IL62600A0 (en) | 1981-06-29 |
| NL8101741A (en) | 1981-11-02 |
| CA1175521A (en) | 1984-10-02 |
| ES501182A0 (en) | 1982-06-16 |
| IT8120998A1 (en) | 1982-10-08 |
| SE447437B (en) | 1986-11-10 |
| FR2480534B1 (en) | 1985-05-31 |
| IT1137680B (en) | 1986-09-10 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| NUG | Patent has lapsed |
Ref document number: 8102048-9 Effective date: 19890427 Format of ref document f/p: F |