Enhancement in the 32 kbit/s ADPCM Algorithm for FSK Voice- Band Data Signals
01 January 1988
Due to the feedback architecture of the standard CCITT and ANSI 32 kb/s ADPCM coders, large transitional errors occur when characteristics of the input signal suddenly change. This particularly holds for FSK modems which transmit a single frequency signal between actual characters. A mechanism which identifies these transitions and reduces errors is presented