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:
Nov. 20, 2001
Filed:
Nov. 03, 1998
Naoya Kobayashi, Odawara, JP;
Seiichi Mita, Kanagawa-ken, JP;
Masaharu Kondo, Odawara, JP;
Hideki Sawaguchi, San Diego, CA (US);
Takashi Moriyasu, Kokubunji, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A digital magnetic recording/reproducing apparatus that has an LVA detector, and that is able to maintain the coding rate as high as {fraction (8/9)} or more, and record at a higher density than in the prior art, wherein, in order that the data sequences up to the (2n−1)th best sequence (n>1) are obtained in the order of higher likelihood ratios, and that. the candidates of those data sequences can be produced, the LVA detector has provided therein a unit which replaces the likelihood ratio and path memory of the ith best sequence by those of the (2i−1)th best sequence when the contents of the (i−1)th path memory coincide with those of the ith path memory (i=2, 3, . . . , n) and the absolute value of the likelihood ratio difference between the (i−1)th best sequence and the (2i−1)th best sequence is smaller than a decision threshold, or a unit which initializes the likelihood ratio of the ith best sequence to be a constant difference value added to the likelihood ratio of the (i−1)th best sequence when the contents of the (i−1)th path memory and the ith (i=2, 3, . . . , n) path memory of the n candidates of data sequences are coincident.