Goke US Research Laboratory

Ko-Chung Tseng

Engling Yeo

Chandra Varanasi

A method and apparatus is described for assigning columns of an LDPC H matrix to a plurality of decoding logics for efficient decoding of codewords. The rows of the LDPC H matrix are evaluated in a number of different orderings, and for each row in each ordering, a number of columns containing non-zero circulants are determined that cannot be evenly distributed to a plurality of decoding logics. As each row is evaluated, one or more columns of the LDPC H matrix are assigned to temporary bins for storage. After the LDPC H matrix has been evaluated a plurality of times, the arrangement that resulted in the fewest number of 'mismatched' columns is selected, and the columns of the LDPC H matrix that were assigned to the temporary storage bins for that particular row arrangement is used to assign the columns in the bins to the plurality of decoding logics.

Method and apparatus for efficient data decoding

A method and apparatus for efficient data decoding is described. Data is encoded by an LDPC encoder using a G matrix. An LDPC decoder uses a modified H matrix to decode encoded blocks of data, the modified H matrix having at least two columns of its circulants swapped with each other. The encoded blocks of data are stored, decoded and reconstructed in an order that considers the circulants in the columns that have been swapped.

Look-ahead LDPC decoder. In an exemplary embodiment, a method includes generating a message (QA) to a first check node, the QA message is generated from a result (RA) from the first check node, and generating a message (QB) to a second check node, the QB message is generated from the result (RA) and is transmitted to avoid decoder stall. The method also includes receiving a result (R'A) from the first check node, computing a difference (R&#x2033;A) between the result (R&#x2032;A) and the result (RA), and receiving a result (R&#x2032;B) from the second check node. The method also includes computing a bit value P(B) using the difference (R&#x2033;A) and the result (R&#x2032;B).

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Santa Clara, CA, United States of America

Ko-Chung Tseng