Double-loop sigma-delta modulation with DC input

Abstract

A discrete-time model having a two-bit (2-b) quantizer is analyzed exactly, and an analytical expression for the quantizer noise sequence is found. Rigorous answers are then provided to two fundamental questions for a double-loop sigma-delta modulation system with DC input: (1) What is the long-term statistical behavior of the internal quantizer noise? (2) How does the asymptotic mean square sigma-delta quantization error vary as a function of the oversampling ratio?.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>