Accession Number : ADA298948

Title :   High-Speed Fixed- and Floating-Point Implementation of Delta-Operator Formulated Discrete-Time Systems.

Descriptive Note : Interim rept. 1 Jan-30 Jun 94,

Corporate Author : MIAMI UNIV CORAL GABLES FL

Personal Author(s) : Premaratne, Kamal ; Bauer, Peter H.

PDF Url : ADA298948

Report Date : 03 AUG 1994

Pagination or Media Count : 10

Abstract : This report addresses the analysis and design of finite word- length implementations of linear time-invariant delta-operator formulated discrete-time systems and the development of a 2-D delta-operator state-space model. It is shown that, in fixed-point arithmetic, linear time-invariant systems implemented with delta- operator do not generally outperform their shift-operator counterparts; they always show unstable limit cycle behavior and convergence to incorrect equilibria independent of realization and sampling time. Coefficient sensitivity is still superior. With floating-point arithmetic, delta-operator implementations consistently perform better than their shift-operator counterparts. They show superior quantization noise and sensitivity properties. Zero convergence problem of the fixed-point case does not exist if the mantissa length is sufficiently large. Noting these attractive finite wordlength properties, the concept of delta-operator has been extended to the multi-dimensional case. A 2-D state-space model, the notions of gramians, and balanced realization have been introduced. As for the 1-D case, sensitivity and roundoff noise behavior was analyzed. Realiviza tion that 1-D case, sensitivity are equivalent to balanced realizations. The problem of directly checking stability in the delta-domain has also been addressed. (AN)

Descriptors :   *MATHEMATICAL MODELS, *FLOATING POINT OPERATION, LINEAR SYSTEMS, STABILITY, COMPUTATIONS, TWO DIMENSIONAL, INPUT OUTPUT PROCESSING, MATHEMATICAL FILTERS, CONVERGENCE, DISCRETE DISTRIBUTION, OPERATORS(MATHEMATICS), ARITHMETIC, DIGITAL FILTERS.

Subject Categories : Operations Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE