Abstract: Methods and circuits are disclosed for forward-error-correction (FEC) decoding. A plurality of symbols are received in an interleaved format of rows and columns of the symbols. A plurality of FEC decoding iterations are performed on the plurality of symbols. Each decoding iteration performs FEC decoding of the rows of the plurality of symbols and performs FEC decoding of the columns of the plurality of symbols. After performing the decoding iterations, rows in error and columns in error of the plurality of symbols are determined. In response to the determined rows in error and the determined columns in error matching a deadlock pattern, symbols at intersections of the determined rows and columns in error are determined. Bits of one or more symbols of the determined symbols are inverted. After the inverting of the bits, one or more of the FEC decoding iterations are performed.

Abstract: A method for matrix expansion is disclosed. In this method, a Progressive Edge Growth (“PEG”) expanding of an H matrix by a coder is used to provide an expanded H matrix. An Approximate Cycle Extrinsic Message Degree (“ACE”) expanding of the expanded H matrix by the coder is used to provide a parity check matrix for a code. The ACE expanding includes initializing a first index to increment in a first range associated with a PEG expansion factor, expanding each non-zero element in the expanded H matrix with a random shifted identity matrix for the first range, initializing a second index to increment in a second range associated with the first index and an ACE expansion factor, and performing an ACE detection for each variable node in the second range for the variable nodes of the parity check matrix. The coder outputs information using the parity check matrix.

Abstract: An apparatus is disclosed. In this apparatus, at least one coder block has a parity check matrix. The parity check matrix comprises each element of an H matrix expanded by a Progressive Edge Growth (“PEG”) expansion factor and an Approximate Cycle Extrinsic Message Degree (“ACE”) expansion factor.

Abstract: A decoding circuit is disclosed that includes a decoding pipeline configured to receive a data block that includes a plurality of data symbols, encoded with a Reed-Solomon (RS) FEC coding thereafter further encoded by a second FEC coding. The data block also includes a first and second sets of FEC datagrams for correcting received words of the plurality of data symbols encoded with the RS FEC coding and second FEC coding, respectively. Each decoding stage of the pipeline is configured to decode the plurality of data symbols using the first and second sets of FEC datagrams. A post-processing circuit connected to an output of the pipelines is configured to perform bitwise RS decoding of ones of the plurality of data symbols in error.

Abstract: In one embodiment, a circuit for FEC decoding includes first and second syndrome calculation circuits, configured to calculate FEC syndromes for rows and columns of symbols in a de-interleaved format, respectively. A decoding circuit is configured to arrange the symbols into windows. Each window includes a plurality of sequential rows and sequential columns of the symbols in the de-interleaved format. The decoding circuit is configured to place N of the windows in a group and perform M decoding iterations of the windows in the group. In each decoding iteration, the decoding circuit performs FEC decoding of rows of each of the windows in the group followed by FEC decoding of columns of each of the windows in the group.