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:
Aug. 14, 2012
Filed:
Aug. 11, 2009
Yang Han, Santa Clara, CA (US);
Kiran Gunnam, San Jose, CA (US);
Shaohua Yang, San Jose, CA (US);
Hao Zhong, Milpitas, CA (US);
Nils Graef, Milpitas, CA (US);
Yuan Xing Lee, San Jose, CA (US);
Yang Han, Santa Clara, CA (US);
Kiran Gunnam, San Jose, CA (US);
Shaohua Yang, San Jose, CA (US);
Hao Zhong, Milpitas, CA (US);
Nils Graef, Milpitas, CA (US);
Yuan Xing Lee, San Jose, CA (US);
LSI Corporation, Milpitas, CA (US);
Abstract
In one embodiment, an LDPC decoder has a plurality of check-node units (CNUs) and a controller. Initially, the CNUs generate check-node messages based on an initial offset value selected by the controller. If the decoder converges on a trapping set, then the controller selects new offset values for missatisfied check nodes (MSCs), the locations of which are approximated, and/or unsatisfied check nodes (USCs). In particular, offset values are selected such that (i) the messages corresponding to the MSCs are decreased relative to the messages that would be generated using the initial offset value and/or (ii) the messages corresponding to the USCs are increased relative to the messages that would be generated using the initial offset value. Decoding is then continued for a specified number of iterations to break the trapping set. In other embodiments, the controller selects scaling factors rather than, or in addition to, offset values.