Neural network and DSP based decoder for DTMF signals

A novel approach for the efficient digital decoding of DTMF signals used in telecommunications is based on an artificial neural network (ANN) implemen ted on a digital signal processor (DSP). After the appropriate training pha se the ANN is able to associate a digital output corresponding to the recei ved DTMF signal. The proposed approach may allow the possibility of impleme nting a real-time non-intrusive decoder. This decoder is fully described an d particular attention paid to the solutions adopted for optimising the AWN 's computation on the DSP. A comparison is made of the performance obtained by the proposed approach, and that, recommended by the CCITT standard. Fin ally, experimental results are given which highlight the performance of the apparatus in different real conditions in DTMF signal decoding.