CVSD
Continuously Variable Slope Delta Modulation: Delta modulation with variable step size.
A method by which a voice signal is digitized for
transmission, and then changed back to an analogue voice signal during reception.
Delta modulation (DM) and Continuously Variable Slope Delta modulation (CVSD) are differential
waveform quantization techniques. Both employ two level quantizers (one bit). CVSD is basically DM with an
adaptive quantizer.
Applying adaptive techniques to a DM quantizer allows for continuous step size adjustment.
By adjusting the quantization step size, the coder is able to represent low amplitude signals with
greater accuracy (where it is needed) without sacrificing performance on large amplitude signals.