Embodiments of the invention provide a check node processing unit implemented in a decoder, said decoder being configured to decode a signal encoded using an error correcting code, said signal comprising symbols, the check node processing unit being configured to receive at least two input messages and to generate at least one output message, each message comprising a plurality of components, each component comprising a value of a symbol and a reliability metrics associated with said symbol, wherein the check node processing unit comprises: a data structure (31) configured to store said input messages, the components of the input messages being associated with an integer index in the data structure; a data processing unit (33) configured to apply one or more iterations of a transformation operation to at least a part of the data structure, each iteration of the transformation operation being performed to arrange the components of said input messages in said data structure (31) depending on at least some of the components of the messages associated with a given value of the integer index, which provides a transformed data structure; a calculation unit (35) configured to determine said at least one output message from the components comprised in said transformed data structure.

According to one embodiment, a controller includes a decoder, calculation section, table creation, and control section. The decoder converts ECC frames into likelihood information based on a set table, generates decoded ECC frames by decoding using the likelihood information and switches the set table when there is an ECC frame in which the decoding is unsuccessful. The calculation section generates calculation data based on an ECC frame of calculation target among the decoded ECC frames and its ECC frame before decoded. The table creation section sets the new table to the decoder based on the calculation data. The control section controls the calculation target so that a calculation in the calculation section is not repeated for an ECC frame in which the decoding is successful.

Real-time selection of interference cancellation schemes based on transmission parameters and amount of resource overlap between the desired payload and the interfering payload. Codeword level interference cancellation may be performed where the signal quality of the interfering signal indicates that the interfering payload will be decoded correctly. When performed, codeword level interference cancellation may be monitored to determine if decoding the interfering payload is converging. Other interference cancellation schemes may be selected based on the signal quality of the interfering signal or non-converging decode of the interfering payload. The number of iterations for iterative decoding in codeword level interference cancellation may be dynamically selected. The decoder output (e.g., soft bits) may be used to perform interference cancellations before the decoder is fully converged. Iterative decoding may be performed in multiple passes and soft decision output form one pass may be used to initialize the decoder for a subsequent pass.

System and methods described herein includes a method for iterative decoding. The method includes instantiating an iterative decoding procedure to decode a codeword. At each iteration of the iterative decoding procedure, the method further includes retrieving information relating to a plurality of current decoding variables at a current iteration, determining a first current decoding variable to be skipped for the current iteration based on the information, and processing a second decoding variable without processing the first decoding variable to update related decoding variables from the plurality of current decoding variables.

Methods and systems are disclosed for decoding codewords, wherein codewords comprise at least one circulant and are stored in a first dimension of a matrix, and wherein each circulant in a codeword is associated with a location in a second dimension in the matrix. The method includes determining whether a first location in a second dimension of a first circulant of a first codeword corresponds to a second location in the second dimension of a second circulant of a second codeword. The method includes, in response to determining that the first location does not correspond to the second location, decoding the first and second circulant with a first decoding process. The method includes, in response to determining that the first location corresponds to the second location, decoding the first and second circulant with a second decoding process.

An error correction method includes performing a first error correction operation, the first error correction operation including performing a syndrome check operation by calculating a syndrome matrix corresponding to a codeword based on a parity check matrix, performing a decoding operation for the codeword according to a result of the syndrome check operation, and iterating the decoding operation until the syndrome check operation is passed for a codeword acquired as the decoding operation is performed or an iteration count of the decoding operation reaches a threshold count; accumulating syndrome matrixes, which are calculated as the decoding operation is iterated, to an accumulation matrix; and performing a second error correction operation for a last codeword acquired through the iterating of the decoding operation for the codeword, based on the accumulation matrix, when the iteration count reaches the threshold count.

It is disclosed an optical coherent receiver comprising a number of decoding blocks configured to implement iterations of a FEC iterative message-passing decoding algorithm. The decoding blocks are distributed into two (or more) parallel chains of cascaded decoding blocks. The receiver also comprises an intermediate circuit interposed between the two parallel chains. The optical coherent receiver is switchable between (i) a first operating mode, in which the intermediate circuit is inactive and the two parallel chains separately implement the FEC message-passing decoding algorithm on respective client channels; and (ii) a second operating mode, in which the intermediate circuit is active and the two parallel chains jointly implement the FEC message-passing decoding algorithm on a same client channel, by cooperating through the intermediate circuit.

Systems and method relating generally to solid state memory, and more particularly to systems and methods for recycling data in a solid state memory. The systems and methods include receiving a data set maintained in a memory device, applying at least one iteration of a data decoding algorithm to the data set by a data decoder circuit to yield a decoded output, counting the number of iterations of the data decoding algorithm applied to the data set to yield an iteration count, and recycling the data set to the memory device. The recycling is triggered based at least in part on the iteration count.

A syndrome weight of failed decoding attempts is used to select parameters for future read retry operations. The following exemplary steps are performed until a decoding success or a predefined limited number of readings is reached: (i) reading a codeword using different read threshold voltages; (ii) mapping the readings to a corresponding likelihood value using a likelihood value assignment; and (iii) recording a syndrome weight for failed decoding attempts of the readings using the different read threshold voltages. Once the predefined limit is reached, the following exemplary steps are performed: (i) mapping the readings to a corresponding likelihood value using different likelihood value assignments, and (ii) recording a syndrome weight for failed decoding attempts of the readings using the different likelihood value assignments; and using a given read threshold voltage and/or a likelihood value assignment associated with a substantially minimum syndrome weight as an initial read threshold voltage and/or a higher priority read threshold voltage for subsequent read retry operations.

A memory device can include a memory array, a processor coupled to the memory array, and a decoding apparatus. The decoding apparatus is configured to perform parallel decoding of codewords. Each of the codewords has a plurality of data blocks, and each data block having a number of data bits. The decoding apparatus is configured to decode, in parallel, a first codeword with one or more other codewords to determine error information associated with each codeword. For errors in a common data block shared between two codewords being decoded in parallel, the error information includes a data block identifier and associated error bit patterns. Further, the decoding apparatus is configured to update the codewords based on the error information.