Dsp-based Dtmf Signal Detection

DTMF signal has been widely used in communication field. Especially in telephone. DTMF mode phone is taking place of press-key phone. DTMF composes one high frequency and low frequency signal. Because that these frequency is rarely used in people voice. So DTMF signal has more anti-jammed capability. At the same time, the DTMF signal can be transmitted in high speed. DTMF has been used in other filed recently.DTMF signal detection is necessary in the DTMF signal practicality .the traditional detection is performed by special chips, this mode has some shortcomings. There is sometimes error in the result of detection when the input signal is consisted of voice and noise, at the same time, because of the limit of special clip ,it can not be used in other filed conveniently.DSP technology has been improved quickly. It has been used in many fields. DSP chips has abundant soft and hardware resources to perform the digital signal process. It can perform complex mathematic analyses, and some chips have been encapsulated complex arithmetic such as FFT, it needs not us to program on it again.In this thesis, we try to achieve the DTMF detection by DSP technology, we will introduce Goertzel Arithmetic .we will compare this arithmetic from DFT. this arithmetic can improve operation speed in DTMF signal detection.We will program on DSP chip in C language. And we will validate the detective result in DSP emluator, in this thesis, we emphasize the detection way's research., we will not design the DTMF signal generator specially, we will use the DTMF signal as input made by software.As the final result, the DSP emluator can perform the DTMF signal detection.