发明名称 |
NON-LINEAR ECHO CANCELLATION FOR WIRELINE MODEMS AND THE LIKE |
摘要 |
The present invention, generally speaking, provides for cancellation of non-linear distortions within the echo path of a communications system by characterizing the nonlinearity, performing digital processing of a data signal to cause substantially the same nonlinearity to be applied to the data signal, and inputting a resulting data signal to a non-linear echo-cancellation path. In an exemplary embodiment, the non-linear echo-cancellation path includes as a nonlinear echo canceller a transversal filter or the like. A separate linear echo cancellation path is also provided. Training of the nonlinear echo canceller follows training of the linear echo canceller. This technique is particularly applicable to cancelling the effects of DAC nonlinearity, which can be readily characterized. Using this technique, cancellation improvement of about 3dB can readily be obtained. Alternatively, instead of achieving a lower residual echo floor, the linearity requirements for the transmit DAC can be relaxed. A lower number of bits of precision allows for lower DAC power consumption. The technique is particularly applicable to DSL applications.
|
申请公布号 |
WO0169811(A8) |
申请公布日期 |
2002.09.06 |
申请号 |
WO2001US01237 |
申请日期 |
2001.02.20 |
申请人 |
VIRATA CORPORATION;PAL, DEBAJYOTI;LU, CHUNG-LI;CHARI, SUJAI |
发明人 |
PAL, DEBAJYOTI;LU, CHUNG-LI;CHARI, SUJAI |
分类号 |
H04B3/23;(IPC1-7):H04B3/23 |
主分类号 |
H04B3/23 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|