DSP implemented speech/voiceband data discriminator

A very powerful speech/voiceband-data discriminator on a 64-kb/s PCM (pulse code modulation) channel, implemented on a single-chip digital signal processor, is presented. Its performance has been evaluated by external simulation (modem of data, recorded tape for speech), giving very good results in terms of response time and false detection probability. The increased clipping of incoming speech channels in DSI (digital speech interpolation) and the limitations of the CCIT G.721 ADPCM (adaptive differential PCM) encoding algorithm with respect to data transmission are pointed out. The total elaboration time to perform discrimination on a single channel is less than 62 μs when a TMS32020 is used. A two-channel speech/voiceband-data discriminator could be implemented on a faster and more powerful digital signal processor.