An Accurate Dual Tone Multiple Frequency Detector Based on The Low-Complexity Goertzel Algorithm

"This article presents a low complexity dual tone multiple frequency (DTMF) signal detector that meets the International Telecommunication Union (ITU) Q.24 DTMF standard while implemented on a general purpose Digital Signal Processor (DSP). The proposed DTMF detector is based on the Goertzel algorithms and is well suited for a multichannel implementation. Our solution offers increased accuracy and noise margins, while preserving the inherited advantages of the Goertzel algorithm (less memory requirements and computational complexity)."