Zero-delay structure for sub-band echo cancellation
    1.
    发明授权
    Zero-delay structure for sub-band echo cancellation 有权
    用于子带回波消除的零延迟结构

    公开(公告)号:US06661895B1

    公开(公告)日:2003-12-09

    申请号:US09414413

    申请日:1999-10-07

    IPC分类号: H04M908

    CPC分类号: H04M9/082

    摘要: A zero-delay structure to be used in sub-band echo cancellation systems. In telecommunications, a delay is usually introduced in sub-band decomposition and/or sub-band reconstruction. This invention will help remove this. This structure not only removes the delay but does not sacrifice the performance of the echo canceller. It is to be used in combination with any sub-band-based echo canceller or wavelet echo canceller.

    摘要翻译: 用于子带回波消除系统的零延迟结构。 在电信中,通常在子带分解和/或子带重建中引入延迟。 本发明将有助于消除这一点。 该结构不仅消除延迟,而且不会牺牲回声消除器的性能。 它与任何基于子带的回波消除器或小波回波消除器组合使用。

    Sub-band echo canceller using optimum wavelet packets and cross-band
cancellation
    2.
    发明授权
    Sub-band echo canceller using optimum wavelet packets and cross-band cancellation 失效
    子带回波消除器使用最佳小波包和交叉带消除

    公开(公告)号:US5937009A

    公开(公告)日:1999-08-10

    申请号:US784849

    申请日:1997-01-15

    摘要: An echo canceller comprising a first wavelet decomposition block for decomposing a reference signal into a plurality of reference wavelet packets; a second wavelet decomposition block for decomposing an echo signal into a plurality of echo signal packets; an adaptive filter bank for receiving and filtering the reference wavelet packets and in response generating a plurality of filtered output packets replicating the echo signal packets; a plurality of subtracters for receiving and subtracting respective ones of the filtered output packets from the echo signal packets and in response generating and applying a plurality of error signals to the adaptive filter bank for modifying the transfer function of the adaptive filter bank; and a wavelet reconstruction block for receiving and reconstructing the error signals to form a residual signal from which the echo signal has been cancelled. Optimum wavelet filters for the best echo cancellation are provided, as are two wavelet echo cancellation structures.

    摘要翻译: 一种回波消除器,包括用于将参考信号分解成多个参考小波包的第一小波分解块; 第二小波分解块,用于将回波信号分解成多个回波信号分组; 自适应滤波器组,用于接收和滤波参考小波包,并且响应于产生复制回波信号分组的多个滤波输出分组; 多个减法器,用于从所述回波信号分组中接收和减去所述经滤波的输出分组中的相应的减法器,并且响应于产生并将多个误差信号施加到所述自适应滤波器组以修改所述自适应滤波器组的传递函数; 以及小波重建块,用于接收和重构误差信号以形成已经从其消除了回波信号的残余信号。 提供了用于最佳回波消除的最佳小波滤波器,两个小波回声消除结构也是如此。