发明名称 |
A METHOD FOR AVOIDING SELF-OSCILLATION IN CONJUNCTION WITH ECHO CANCELLATION. |
摘要 |
<p>A method for avoiding self-oscillation in a four-wire loop in conjunction with echo cancellation is effected with the aid of an adaptive filter (15). Self-oscillation is avoided for both long and short connections and also when signalling with narrow-band signals, by restricting the permitted range of the coefficients of the adaptive filter in a manner such that the absolute value of the filter transfer function will be sufficiently small so that amplification in the four-wire loop is less than one. This is achieved by limiting the absolute value of the filter transfer function (1Hcal), to a value which is smaller than a determined function of the echo transfer function (Hfa) in the far-end of the loop and the echo transfer function (Hne) in the near-end of the loop.</p> |
申请公布号 |
GR3030748(T3) |
申请公布日期 |
1999.11.30 |
申请号 |
GR19990401832T |
申请日期 |
1999.07.13 |
申请人 |
TELEFONAKTIEBOLAGET LM ERICSSON |
发明人 |
LOEFMARK, BENGT, GUSTAV |
分类号 |
H03H21/00;H04B3/23;(IPC1-7):H04B3/23 |
主分类号 |
H03H21/00 |
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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