A New DTMF Detection Scheme Based on NDFT Goertzel Filter
Xiaoqiang Cao · Journal of Southwest University · 2008
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.