Abstract: In this paper the implementation aspects of decoding digital DTMF and R2 signalization tones are analyzed. First, a short review of specifications for DTMF and R2 signalization proposed by ITU-T is made, following by short review of decoding techniques applied in practice. Finally, a new computationally efficient method is proposed and experimentally verified. This method has distinct advantages in multichannel decoding systems and permits decoding in both signaling systems.
Keywords: Signal processing, dual-tone multyfrequency signalization, Goerzel's algorithm, QMF filtering.