Method and apparatus for maintaining convergence within an ADPCM communication system during discontinuous transmission

摘要

An information gap in an ADPCM signal is detected in one or both of a transmitter or receiver. This detection can be accomplished using a voice activity detector. When an information gap is detected, a clock signal to the encoder and/or decoder is interrupted. Alternatively, null frames can be inserted into the encoder and/or decoder. When null frames are used, it is preferable to insert comfort noise into the signal output from the decoder.