Invention Publication
- Patent Title: Speakerphone with echo canceller-suppressor
- Patent Title (中): FernsprechgerätmitEchounterdrückung。
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Application No.: EP90305862.6Application Date: 1990-05-30
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Publication No.: EP0400979A2Publication Date: 1990-12-05
- Inventor: Ford, William Albert
- Applicant: AT&T Corp.
- Applicant Address: 32 Avenue of the Americas New York, NY 10013-2412 US
- Assignee: AT&T Corp.
- Current Assignee: AT&T Corp.
- Current Assignee Address: 32 Avenue of the Americas New York, NY 10013-2412 US
- Agency: Johnston, Kenneth Graham
- Priority: US358030 19890530
- Main IPC: H04M9/08
- IPC: H04M9/08 ; H04B3/20
Abstract:
An echo canceler-suppressor speakerphone arrangement effectively addresses the limitations of regeneration and reverberant return echo inherent in the design of speakerphones. The tendency for regeneration is eliminated by employing adaptive echo cancellation in the receive path of the speakerphone arrangement to cancel speakerphone talker echo across a hybrid and thereby reduce the local loop gain to below unity. And the generation of a reverberant return echo to the far-end party is avoided by employing adaptive echo suppression in the transmit path of the speakerphone arrangement. Near-full and full duplex operation are regularly achieved since the receive path remains open at all times and transmit path has its gain reduced only to the level necessary to suppress excessive reverberant return echo.
Public/Granted literature
- EP0400979B1 Speakerphone with echo canceller-suppressor Public/Granted day:1995-10-25
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