Delta-Sigma Modulation

Abstract

Delta modulation was actively developed for communication purposes in the sixties and seventies. It has also had applications in consumer audio equipment, industrial electronics devices, and precision measurement devices (see Jarman [14]). It consisted in an underlying analog-to-fixed sampling frequency pulse-width-modulation encoding transformation of the signal to be transmitted. Delta modulation was actually used for voice encoding and transmission in the first manned space flights. Its implications in analog to digital conversion schemes were recognized early and a rapid development followed in terms of suitable electronic circuits in countless applications of early computer oriented control of processes. A complete classical account of Delta-modulators, and their simplest modification: Delta-Sigma modulators, extensively used in analog signal encoding, which never benefited from the theoretical basis of sliding mode control, is found in the classical book by Steele [29] and in the excellent book by Norsworthy et al. [17]. A rather complete and informative survey on Delta-Sigma modulation, rich in tutorial material and perspectives, may be found in Reiss [18].