US4609788A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital voice transmission having improved echo suppression
Assignee: Racal Data Communications Inc
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Filing: 1983-03-01
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Granted: 1986-09-02
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Expires: 2003-03-01
Abstract
Abstract A digital communication apparatus with improved echo suppression includes a circuit for detecting the gain of a far talker signal and a circuit for detecting the gain of a near talker signal. These gains are compared and echo suppression is accomplished by suppressing the lesser of the two gains.
Inventors
- 👤 William J. Miller
- 👤 Chun C. Lu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:30
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/20
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
107 words
A digital communication apparatus for transmitting and receiving a compressed digital representation of speech produced by a near talker and a far talker respectively, said compressed digital representation of speech including a coded gain parameter related to speech energy, said apparatus comprising: transmission gain detection means for reading the gain parameter of said near talker's compressed digital representation of speech; receiver gain detection means for reading the gain parameter of said far talker's compressed digital representation of speech; means for detection which of said near talker and far talker gain parameters has a lesser value, and for reducing the gain parameter detected to have the lesser value.
Claim 2
Dependent Claim
107 words
A digital communication apparatus for transmitting and receiving a compressed digital representation of speech produced by a near talker and a far talker respectively, said compressed digital representation of speech including a coded gain parameter related to speech energy, said apparatus comprising: transmission gain detection means for reading the gain parameter of said near talker's compressed digital representation of speech; receiver gain detection means for reading the gain parameter of said far talker's compressed digital representation of speech; means for detection which of said near talker and far talker gain parameters has a lesser value, and for reducing the gain parameter detected to have the lesser value.
Claim 3
Independent Claim
107 words
A method of echo suppression in a digital communication link having near and far ends, said digital communication link communicating a compressed digital representation of speech produced by a near talker and a far talker, said compressed digital representation of speech including a coded gain parameter related to speech energy, the method comprising the steps of: at said first end, determining which of said gain parameters has a first lesser value and reducing said gain parameter having said first lesser value; and at said second end, determining which of said gain parameters has a second lesser value and reducing said gain parameter having said second lesser value.
Claim 4
Independent Claim
107 words
A method of echo suppression in a digital communication link having near and far ends, said digital communication link communicating a compressed digital representation of speech produced by a near talker and a far talker, said compressed digital representation of speech including a coded gain parameter related to speech energy, the method comprising the steps of: at said first end, determining which of said gain parameters has a first lesser value and reducing said gain parameter having said first lesser value; and at said second end, determining which of said gain parameters has a second lesser value and reducing said gain parameter having said second lesser value.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-09-01 | 1990-03-03 | 1990-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-01 | 1994-03-03 | 1994-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-01 | 1998-03-03 | 1998-09-02 | $7700.00 | Window Closed / Lapsed |