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:
Jul. 15, 1997
Filed:
Jun. 27, 1995
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
Digital operational circuitry includes a first adder/subtractor for adding a first pathmetric to a first branchmetric to develop a first value of pathmetric, and a second adder/subtractor for subtracting the first branchmetric from a second pathmetric to develop a second value of pathmetric. The addition and subtraction are performed by the first and second adder/subrtactors complementarily to each other. The first and second values of pathmetric are compared in likelihood to each other, and in response to the results from the comparison, either of the first and second values of pathmetric is selected and stored in a storage. The circuitry also includes a third adder/subtractor for adding the pathmetric read out from the storage to a second branchmetric to develop a third value of pathmetric, and a fourth adder/subtractor for subtracting the second branchmetric from the pathmetric read out from the storage to develop a fourth value of pathmetric. The third and fourth values of pathmetric are compared in likelihood, and in response to the comparison results either of the third and fourth values of pathmetric is developed as a pathmetric.