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US 4,228,517 AGranted
Recursive filter
AssigneeJames N. Constant
InventorJames N. Constant
Life of this patent
Estimating the term…
Abstract
A recursive filter characterized by increased efficiency and accuracy and incorporating a step decision circuit which reduces filter noise, error and size. Efficiency is obtained by reducing the requirement for bulk memory and the number of multipliers while accuracy is obtained by reducing error portions of data and coefficient words in the filter.
Claims25
A recursive filter characterized by increased efficiency and accuracy and comprising:
- a feedforward circuit having as input the data sequence x.sub.n and coefficient sequence .alpha.,
- said feedforward circuit having first data and coefficient memories and at least one feedforward multiplier and integrator;
- a feedback circuit having as input the data sequence y.sub.n and coefficient sequence .beta.,
- said feedback circuit having second data and coefficient memories and at least one feedback multiplier and integrator;
- a step decision circuit connected in at least one of said feedforward and feedback circuits;
- and
- means connecting said feedforward and feedback circuits for forming said recursive filter, with said step decision circuit including means for establishing a threshold for each value of n, said filter having as input the data sequence x.sub.n and providing as output the data sequence y.sub.n where n=1, 2, . . . , N.
4 more elements
A method for the implementation of recursive filters characterized by increased efficiency and accuracy and including the steps of:
- inputting data sequence x.sub.n and coefficient sequence .alpha. to a feedforward circuit having data and coefficient memories and at least one multiplier and integrator;
- inputting data sequence y.sub.n and coefficient sequence .beta. to a feedback circuit having data and coefficient memories and at least one multiplier and integrator;
- connecting a step decision circuit in at least one of said feedforward and feedback circuits;
- and
- connecting said feedback and feedforward circuits to form a recursive filter, with said step decision circuit establishing a threshold for each value of n, said filter having as input the data sequence x.sub.n and providing as output the data sequence y.sub.n where n=1, 2, . . . , N.
2 more elements
Dependencies are inferred from the claim text.