Effect of various dither forms on quantization errors of ideal A/D converters

The quantization error of a quantizer (ideal A/D converter) is investigated. Correlation between quantization error and quantizer input is considered. The input signal is taken as a sinusoid due to its importance in instrumentation systems. The cases of no dither, uniform dither, and discrete (digital) dither are considered. Effects of the dither probability density function (PDF) are discussed. The relationship between uniform dithered and discrete dithered quantizer inputs is derived. Spectra of the average quantization error, corresponding to an arbitrary input signal, are investigated. Different dither forms (Gaussian, uniform, and discrete) are compared, and the effects of the dither PDF are discussed. A quantitative basis for comparing dither forms, and hence, selecting the one most appropriate for a particular application, is provided.>