基于NDFT Goertzel滤波器的DTMF信号检测的改进方法(英文)

A New DTMF Detection Scheme Based on NDFT Goertzel Filter

提出了一种基于NDFT Goertzel滤波器和逻辑判断的DTMF信号检测的改进方法.传统的基于Goertzel算法的检测方法需要计算8个频率点上的DFT,而改进方法根据按键不同只计算最多6个,最少2个频率点的NDFT.检测数字按键时,对于每个按键计算频率点数的期望值为4.1.改进的检测方法满足ITU的大部分规定.

A novel approach based on NDFT Goertzel filter and logical judgment to detect DTMF signal is presented. With only one Goertzel filter, at most six and at least two samples of NDFT, according to which key is pressed, are sufficient for detection. The expected samples of NDFT are 4.1 when digits （0-9） are detected. It is demonstrated that the new approach meets most of ITU specifications.