Linear predictive echo canceller integrated with RELP vocoder
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Sep 29, 1987
Grant Date -
N/A
app pub date -
Sep 5, 1986
filing date -
Sep 5, 1986
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A linear predictive echo canceller is integrated with a RELP vocoder in a two-way communications network, in which a received digitized speech signal synthesized by the RELP vocoder from a residual signal received with linear prediction coefficients is echoed onto a transmit channel and combined with a transmitted digitized speech input signal that is to be analyzed by a RELP vocoder for transmission. The echo canceller cancels the echoed signal from the transmit channel by generating a foreground transmit signal by subtracting a foreground estimate of the echoed signal from the combined signal; and providing the foreground transmit signal on the transmit channel for ananlysis by the RELP vocoder. In order to generate the foreground transmit signal, the echo canceller filters the received digitized speech signal with adaptation coefficients to generate the foreground estimate of the echoed signal; prewhitens the foreground transmit signal by using the received linear prediction coefficients; and generates the adaptation coefficients by cross correlating the received residual signal with the prewhitened foreground transmit signal and adding the product of said cross correlation to the adaptation coefficients used for generating the foreground estimate of the echoed signal.
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully