Implementation of Signal Processing Algotithms in C language using Texas Instruments C6713 DSK board using TMS320C6713 DSP CPU.
Dual-tone multifrequency (DTMF) is a method used to dial telephone numbers or to issue commands to switching systems. DTMF is widely used for telecommunication signaling between telephone handsets and switching centers over analog telephone lines in voice-frequency bands.
DTMF is used in push-button telephones for tone dialing. This version of DTMF is an AT&T registered trademark and is called Touch-Tone.
The infinite impulse response (IIR) filter is a recursive filter in that the output from the filter is computed by using the current and previous inputs and previous outputs.
Because the filter uses previous values of the output, there is feedback of the output in the filter structure. The design of the IIR filter is based on identifying the pulse transfer function G(z) that satisfies the requirements of the filter specification. This can be undertaken either by developing an analogue prototype and then transforming it to the pulse transfer function, or by designing directly in digital.