A/D Conversion With Imperfect Quantizers
Academic Article
Overview
Identity
Additional Document Info
Other
View All
Overview
abstract
This paper analyzes mathematically the effect of quantizer threshold imperfection commonly encountered in the circuit implementation of analog-to-digltal (A/D) converters such as pulse code modulation (PCM) and sigma-delta () modulation. modulation, which is based on coarse quantization of oversampled (redundant) samples of a signal, enjoys a type of self-correction property for quantizer threshold errors (bias) that is not shared by PCM. Although "classical" modulation is inferior to PCM in the rate-distortion sense, this robustness feature is believed to be one of the reasons why modulation is preferred over PCM in A/D converters with imperfect quantizers. Motivated by these facts, other encoders are constructed in this paper that use redundancy to obtain a similar self-correction property, but that achieve higher order accuracy relative to bit rate compared to classical . More precisely, two different types of encoders are introduced that exhibit exponential accuracy in the bit rate (in contrast to the polynomial-type accuracy of classical ) while possessing the self-correction property. 2006 IEEE.