Dither Signals and Their Effect on Quantization Noise

In this paper, the conditions a dither signal must meet so that the quantizer noise can be considered independent of the signal are derived for a quantizer having a finite number of levels. An infinite class of dither signals which satisfy these conditions is given. It is seen that the most useful member of this class is one whose probability density function is uniformly distributed over a quantizing interval. It is also shown that a necessary and sufficient condition for the noise n(t) to be independent of the signal x(t) is that a measurable quantity, called the "D" factor, be zero.