Multi-loop sigma-delta quantization: spectral analysis

Author

He, Ning ; Buzo, Andres ; Kuhlmann, Federico

Author_Institution

Fac. de Ingenieria, Univ. Nacional Autonoma de Mexico, Mexico

fYear

1988

fDate

11-14 Apr 1988

Firstpage

1870

Abstract

An exact spectral analysis of oversampled discrete-time L-loop ( L⩾2) sigma-delta modulator (ΣΔM) with DC (constant) input is presented. It is shown by a novel application of ergodic theory that the embedded quantizer error sequence is asymptotically uniformly distributed, white and uncorrelated with the input, a fact usually assumed a priori in the linearized models. It was found that for the following linear demodulators: (1) optimum FIR (finite-impulse response) filter, (2) sinc^k filters (k ⩾L+1), and (3) the ideal low-pass filter, the overall system (ΣΔM plus demodulator) can provide a normalized average quantization noise power inversely proportional to the (2L +1)-st power of the oversampling ratio, confirming the performance superiority of multiloop ΣΔM over single-loop ΣΔM

Keywords

analogue-digital conversion; delta modulation; modulators; spectral analysis; ADC; FIR filters; embedded quantizer error sequence; ergodic theory; linear demodulators; low-pass filter; multiloop sigma delta quantisation; oversampled discrete time modulator; oversampling ratio; quantization noise power; sinc filters; spectral analysis; CADCAM; Computer aided manufacturing; Delta-sigma modulation; Demodulation; Feedback loop; Finite impulse response filter; Low pass filters; Nonlinear filters; Quantization; Spectral analysis;

fLanguage

English

Publisher

ieee

Conference_Titel

Acoustics, Speech, and Signal Processing, 1988. ICASSP-88., 1988 International Conference on

Conference_Location

New York, NY

ISSN

1520-6149

Type

conf

DOI

10.1109/ICASSP.1988.196989

Filename

196989