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. 18, 2000
Filed:
Oct. 18, 1996
Jonathan James Ashley, Los Gatos, CA (US);
Brian Harry Marcus, Los Altos, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
The present invention is an apparatus and method for detecting a codeword from a data stream comprising a series of sequences of samples representing intensities of an analog signal. The data stream may be output from, for example, a holographic storage device. The data stream is encoded using a code which may be represented by a trellis. One embodiment of the present invention uses a block encoded balanced code, one embodiment uses a finite state encoded balanced code and another embodiment uses a finite-state encoded DC free code. Each code defines a set of codewords which meet the constraints of the code. The codewords are detected from a sequence of samples by selecting the codeword having the greatest correlation with the sequence of samples. In a preferred embodiment, the correlation detection is implemented using the Viterbi process to iteratively determine correlations and codewords for each state at each level of the trellis based on the correlations at the preceding level of the trellis.