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:
Apr. 10, 2001
Filed:
Mar. 03, 1999
William G. Bliss, Thornton, CO (US);
Sian She, Broomfield, CO (US);
Cirrus Logic, Inc., Austin, TX (US);
Abstract
A sampled amplitude read channel for use in disk storage systems (magnetic or optical) is disclosed comprising a simplified branch metric calculator for use in a trellis sequence detector. Instead of computing the traditional Euclidean branch metric as the squared difference between the actual signal sample and the expected signal sample of the target partial response, the present invention computes a simplified branch metric which is then saturated in order to reduce the number of bits required to calculate and store the branch metrics, thereby simplifying the branch metric calculators as well as reducing the add-compare-select (ACS) circuitry for each state in the trellis. Furthermore, the saturation technique of the present invention is substantially data independent meaning that the saturation threshold is essentially independent from the signal samples used to compute the branch metric.