On line speech/Data-modem identifier for telephone network

The application of efficient speech compression schemes to digital telephony is hindered by the potential transit of non-speech signal generated by data modems. This obstacle can be overcome through on-line speech/data-modem identification. This paper presents an efficient yet simple way to resolve this problem for a class of FSK and PSK modems. The approach uses a pattern classifier technique based on four parameters extracted from 8ms- block analysis. These are the average log magnitude, the extremum count, the zero-crossing count and max-to-mean amplitude deviation. The speech/data-modem decision is obtained through a piecewise-linear partitionning of the parameter space.