公开(公告)号：US5631957A

公开(公告)日：1997-05-20

申请号：US401176

申请日：1995-03-09

申请人： Israel Greiss ,  Rami Drucker ,  Gil Montag ,  Ophir Shabtay ,  David Almagor

发明人： Israel Greiss ,  Rami Drucker ,  Gil Montag ,  Ophir Shabtay ,  David Almagor

IPC分类号： H04B3/23 ,  H04M11/00

CPC分类号： H04B3/23

摘要： Near-end echo-reduction is achieved by passing a transmit signal through a first filter bank and feeding a remote signal plus an echo of the transmit signal through a second filter bank, then subtracting a gain-coefficient-compensated (scaled) version of the filtered transmit signal from the filtered-composite-remote signal to obtain an echo-reduced receive signal. The echo-reduced receive signal is suitably employed by tone decoders, voice response mechanisms, and the like, in a telephone system, and avoids false alarms due to near-end echo. In one embodiment, the gain coefficients are fixed for each frequency of interest. In another embodiment, the gain coefficients are dynamically arrived at based on the filtered transmit signal and the echo-reduced receive signal. The two filter banks can be combined in one, multiplexed filter bank.

摘要翻译： 通过将发射信号通过第一滤波器组并且通过第二滤波器组馈送远程信号加上发射信号的回波，然后减去增益系数补偿（缩放）版本来实现近端回波减小 滤波后的复合远程信号的发射信号，以获得回波减小的接收信号。 回声减小接收信号在电话系统中由音调解码器，语音响应机制等适当地使用，并且避免由于近端回波引起的误报。 在一个实施例中，对于感兴趣的每个频率，增益系数是固定的。 在另一个实施例中，增益系数是基于滤波的发射信号和回波减小的接收信号来动态地得到的。 两个滤波器组可以组合在一个复用滤波器组中。