Application of CVSD with delayed decision to narrowband/Wideband tandem

This paper describes the application of CVSD with delayed decision to improve the quality of LPC encoded speech processed by a CVSD coder. In such tandem configuration, the peaky LPC waveform tends to cause severe slope overload in the subsequent CVSD coder resulting in muffled and unclear speech. By storing a few input signal samples in advance, the delayed-decision CVSD coder generates a more optimum transmitter bit stream that better describes the incoming LPC waveform yielding higher signal-to-noise ratios in the overall LPC/CVSD tandem speech.