公开(公告)号：US5774847A

公开(公告)日：1998-06-30

申请号：US933531

申请日：1997-09-18

申请人： Chung Cheung Chu ,  Rafi Rabipour

发明人： Chung Cheung Chu ,  Rafi Rabipour

IPC分类号： G10L11/02 ,  G10L19/04 ,  G10L9/14

CPC分类号： G10L25/78 ,  G10L19/04

摘要： In methods and apparatus for distinguishing stationary signals from non-stationary signals, a set of Linear Predictive Coding (LPC) coefficients characterizing spectral properties of the signal for each of a plurality of successive time intervals, including a current time interval, is determined. The LPC coefficients are averaged over a plurality of successive time intervals preceding the current time interval, and a cross-correlation of the LPC coefficients for the current time interval with the averaged LPC coefficients is determined. The signal is declared to be stationary in the current time interval when the cross-correlation exceeds a threshold value, and is declared to be non-stationary in the current time interval when the cross-correlation is less than the threshold value. The methods and apparatus are particularly applicable to detection of transitions between an absence of speech state, characterized by a stationary signal, and a presence-of-speech state characterized by a non-stationary signal.

摘要翻译： 在用于区分平稳信号和非平稳信号的方法和装置中，确定了表征包括当前时间间隔的多个连续时间间隔中的每一个的信号的频谱特性的一组线性预测编码（LPC）系数。 LPC系数在当前时间间隔之前的多个连续时间间隔中被平均，并且确定当前时间间隔的LPC系数与平均的LPC系数的互相关。 信号在互相关超过阈值的当前时间间隔中被声明为静止，并且当互相关小于阈值时，在当前时间间隔中被声明为不稳定。 所述方法和装置特别适用于检测由不稳定信号表征的语音状态的不存在以及以非平稳信号为特征的语音状态之间的转换。

公开(公告)号：US4853958A

公开(公告)日：1989-08-01

申请号：US201154

申请日：1988-06-02

申请人： Rafi Rabipour ,  Michael G. Beyrouti ,  Paul Mermelstein

发明人： Rafi Rabipour ,  Michael G. Beyrouti ,  Paul Mermelstein

IPC分类号： H04Q1/457

CPC分类号： H04Q1/4575

摘要： A dual tone multi-frequency (DTMF) receiver for use in detecting digitally transmitted signals in the telephone industry. The receiver derives linear predictive coefficients for the digital signals in the data frame. This information is used to compute frequency response magnitudes at the DTMF frequencies. A plurality of magnitude comparisons are then performed to verify the presence of true DTMF signals and concurrently the frequency of these signals is obtained.

摘要翻译： 一种双音多频（DTMF）接收机，用于检测电话行业中的数字传输信号。 接收器为数据帧中的数字信号导出线性预测系数。 该信息用于计算DTMF频率的频率响应幅度。 然后执行多个幅度比较以验证真实DTMF信号的存在，同时获得这些信号的频率。