发明名称 |
Adaptive echo-canceller with double-talker detection. |
摘要 |
<p>Method and apparatus are disclosed which provide echo-cancellation in subscriber line audio-processing circuits (SLACs) and modulator-demodulator (modems) The echo-canceller provides a response independent of the amplitude of an error signal representing the difference between the desired and generated signal. The convergence of the echo-cancelling is not influenced by the size of the error signal but only by its sign. In a preferred embodiment, a canonic signed digit filter coefficient updating technique is used for a digital filter (10) implementing the echo-cancellation function. A double-talker detector is advantageously used in conjunction with the echo-canceller. Detection of "double-talker" near-end signals inhibits updating of the echo-canceller filter coefficients. Near-end signals are detected by an energy-averaging filter (26) which selectively samples (28) low-pass filtered signals received by the adaptive filter as received from the far-end talker and low-pass filtered signals received from the near-end talker. Near-end speech or signal is detected if the latter signal exceeds a predetermined function of the former signal.</p> |
申请公布号 |
EP0310055(A1) |
申请公布日期 |
1989.04.05 |
申请号 |
EP19880116052 |
申请日期 |
1988.09.29 |
申请人 |
ADVANCED MICRO DEVICES, INC. |
发明人 |
VAIRVAN, KANNAN P.;MCLEOD, PAUL |
分类号 |
H04B3/23 |
主分类号 |
H04B3/23 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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