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:
Mar. 18, 2003
Filed:
Apr. 10, 2000
Kaneyasu Shimoda, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
In a signal processing apparatus according to the present invention employing PRML technology to reproduce a code sequence recorded on a magnetic recording medium, the maximum likelihood code sequence of a readback signal is obtained by using a likelihood function based on a conditional distribution of each branch corresponding to a quantization level. A plurality of conditional distributions having various deviations are provided, and a suitable conditional distribution is selected in accordance with the characteristic of the readback signal, the signal reproduction performance can be improved. Especially set is a conditional distribution for the nonlinear phenomenon, such as the nonlinear transition shift (NLTS) and the partial erasure (PE). Therefore, it is possible to prevent the signal processing performance deterioration, caused by the nonlinear phenomenon, which tends to appear more often in consonance with the increase in the recording density of a magnetic recording medium. In addition, the recording density for a magnetic recording medium can be increased.