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    STABLE ADAPTIVE FILTER AND METHOD
    1.
    发明公开
    STABLE ADAPTIVE FILTER AND METHOD 审中-公开
    稳定剂适应症过滤器在HERSTELLUNGSVERFAHREN

    公开(公告)号：EP1057259A1

    公开(公告)日：2000-12-06

    申请号：EP99973514.5

    申请日：1999-11-10

    申请人： Nortel Networks Limited

    发明人： DING, Heping

    IPC分类号： H03H21/00

    CPC分类号： H03H21/0012 ,  H03H21/0043 ,  H03H2021/0054

    摘要： Stable adaptive filter and method are disclosed. The invention solves a problem of instability associated with Fast Affine Projection adaptive filters caused by error accumulation in an inversion process of an auto-correlation matrix. The Stable FAP provides updating of the adaptive filter coefficients by solving at least one system of linear equations, whose coefficients are the auto-correlation matrix coefficients, by using one of the descending iterative methods having an inherent stability of operation due to intrinsic feedback adjustment. The results of the solution are used to update the filter coefficients. The above approach is applicable for any value of a normalized step size ranging from zero to unity. It allows either direct determining of an updating part of the filter coefficients without determining an inverse auto-correlation matrix, or determining the inverse auto-correlation matrix by descending iterative methods.

    摘要翻译： 公开了稳定的自适应滤波器和方法。 本发明解决了在自相关矩阵的反演过程中由误差积累引起的快速仿射投影自适应滤波器的不稳定性问题。 稳定FAP通过使用由于内在反馈调整而具有固有的操作稳定性的下降迭代方法中的一种，通过求解至少一个系数为自相关矩阵系数的线性方程组来提供自适应滤波器系数的更新。 解决方案的结果用于更新滤波器系数。 上述方法适用于范围从零到一的归一化步长的任何值。 它允许直接确定滤波器系数的更新部分而不确定逆自相关矩阵，或者通过下降的迭代方法来确定逆自相关矩阵。

    DYNAMIC OPTIMIZATION OF HANDSFREE MICROPHONE GAIN
    2.
    发明授权
    DYNAMIC OPTIMIZATION OF HANDSFREE MICROPHONE GAIN 失效
    动态优化方法动手话筒增益

    公开(公告)号：EP0917796B1

    公开(公告)日：2004-03-17

    申请号：EP97936535.0

    申请日：1997-08-08

    申请人： Nortel Networks Limited

    发明人： MCCLENNON, Scott ,  DING, Heping ,  DAL FARRA, David

    IPC分类号： H04M9/08

    CPC分类号： H04M9/082

    摘要： A system and method for dynamically optimizing the analog gain for a microphone in a telephone terminal operable in handsfree mode. The system makes use of a process whereby a relatively inexpensive analog to digital converter is used to meet gain requirements so as to accommodate the loudest echo through transmit path while maintaining an acceptable signal to noise ratio for the quietest talker. The system digital signal processor in conjunction with speech activity detection means is used to provide an optimum microphone gain under all circumstances.