公开(公告)号：US06782095B1

公开(公告)日：2004-08-24

申请号：US09355394

申请日：1999-07-27

申请人： Michael Leong ,  Yuriy Zakharov ,  Sergey Fedorov ,  Galina Titova

发明人： Michael Leong ,  Yuriy Zakharov ,  Sergey Fedorov ,  Galina Titova

IPC分类号： H04M300

CPC分类号： G06F17/141 ,  H04Q1/46

摘要： A general purpose network tone detection method and apparatus that allows the precise and accurate recognition of North American tones (MF, DTMF (Dual-Tone Multifrequency), and CPT (Call Progress Tones)) and international MF-R2 tones as well as taking into consideration other common tones such as Calling Card Service Prompt and Recall Dial. Through the use of the Discrete Fourier Transform (DFT) on small time windows and by providing phase continuity between these windows, the results of the successive DFTs may be combined and processed by a second DFT computation. This second DFT allows higher frequency resolution without requiring the re-computation of the DFT from the time samples. The resulting effect is a tone receiver with both high time and frequency resolution which consequently leads to robust and accurate tone recognition systems conforming even to the most stringent specification while maintaining low computational requirements.

摘要翻译： 一种通用网络音检测方法和装置，允许精确和准确地识别北美音调（MF，DTMF（双音多频）和CPT（呼叫进程音））和国际MF-R2音调以及接收 考虑其他常见音调，如呼叫卡服务提示和回拨。 通过在小时间窗口上使用离散傅立叶变换（DFT）并且通过在这些窗口之间提供相位连续性，可以通过第二DFT计算来组合和处理连续的DFT的结果。 该第二个DFT允许更高的频率分辨率，而不需要从时间样本重新计算DFT。 所产生的效果是具有高时间和频率分辨率的音调接收器，因此导致鲁棒和准确的音调识别系统，甚至符合最严格的规范，同时保持较低的计算要求。