发明名称 |
Method of upstream channel modeling for PCM modem |
摘要 |
A method is presented to enable high speed transmission in the upstream channel from a customer's modem to a PCM modem connected to the public switched digital network. The upstream channel is equalized by having the client modem send a known training sequence in the upstream direction to the server modem. The server modem calculates the cross-correlation between the known training sequence and the sequence as actually received from the client modem. The cross-correlation is then multiplied by the known auto-correlation of the training sequence to produce a model of the channel response. The channel response is then reported to the client modem so that it may adjust its pre-equalizer to construct the signal that the client modem will thereafter send in the upstream direction.
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申请公布号 |
US5887027(A) |
申请公布日期 |
1999.03.23 |
申请号 |
US19970998249 |
申请日期 |
1997.12.24 |
申请人 |
LUCENT TECHNOLOGIES INC. |
发明人 |
COHEN, HERBERT B.;WANG, MINGJIE |
分类号 |
H03M1/18;H04B3/06;H04L25/02;H04L25/03;H04L25/49;H04L27/01;(IPC1-7):H04B1/38 |
主分类号 |
H03M1/18 |
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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