The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 26, 1982
Filed:
Apr. 23, 1979
Joseph L Lehmann, Sarasota, FL (US);
Sangamo Weston, Inc., Norcross, GA (US);
Abstract
A data acquisition system having plural input channels sampled at a first rate by a time division multiplexer applies the samples to a finite impulse response (FIR) discrete filter which generates output samples at a slower rate. The filter forms a set of summations ##EQU1## where Z(t.sub.i) is an input sample at a time t.sub.i, H.sub.i is the i.sup.th value of the filter impulse response, p is a sequence of successive integers, 0, 1, 2, . . . , each of which corresponds to one output sample, K is the length of filter impulse response (number of samples for each output) and R is the ratio of the initial input sample rate to the desired sample rate. A 3 to 1 reduction ratio is achieved with K=31, with the filter forming 11 different overlapping summations, so that after start-up one filtered output sample is outputted after each successive group of 3 inputs. Coefficients and the summations are stored in ROMs and RAMs, and coefficient and memory locations are indexed by counters having a modulo equal to the next integer greater than K/R.