In a transmission device, a determining unit determines, for use in transmission, an LDPC encoding method corresponding to occurrence conditions of external noise from a plurality of LDPC encoding methods each having the same code length and the same code rate and being defined by a different parity check matrix, and an encoding unit generates a codeword bit sequence by encoding transmission data using the LDPC encoding method determined by the determining unit.

A decoder includes circuitry and a soft decoder. The circuitry is configured to receive channel hard decisions for respective bits of a Generalized Low-Density Parity Check (GLDPC) code word that includes multiple component code words, including first and second component code words having one or more shared bits, to schedule decoding of the GLDPC code word, and following the decoding, to output the decoded GLDPC code word. The soft decoder is configured to receive the channel hard decisions corresponding to the first component code word, to further receive soft reliability measures that were assigned to the shared bits in decoding the second component code word, and to decode the first component code word based on the channel hard decisions and the soft reliability measures.

A low-density parity-check (LDPC) apparatus and a matrix trapping set breaking method are provided. The LDPC apparatus includes a logarithm likelihood ratio (LLR) mapping circuit, a variable node (VN) calculation circuit, an adjustment circuit, a check nodes (CN) calculation circuit and a controller. The LLR mapping circuit converts an original codeword into a LLR vector. The VN calculation circuit calculates original V2C information by using the LLR vector and C2V information. The adjustment circuit adjusts the original V2C information to get adjusted V2C information in accordance with a factor. The CN calculation circuit calculates the C2V information by using the adjusted V2C information, and provides the C2V information to the VN calculation circuit. The controller determines whether to adjust the factor. When LDPC iteration operation falls into matrix trap set, the controller decides to adjust the factor so that the iteration operation breaks away from the matrix trap set.

Systems and method relating generally to data processing, and more particularly to systems and methods for accessing a data set from a solid state storage device, using a data decoding circuit to apply a data decoding algorithm to the data set to yield a decoded output, where the decoded output includes at least one error, identifying at least one critical location in the data set, and estimating a voltage associated with the data in the data set corresponding to the critical location.

A memory controller for use in a data storage device is provided. The memory controller includes a variable-node circuit and a check-node circuit. The check-node circuit obtains a codeword difference from the variable-node circuit, and calculates a syndrome according to the codeword difference. The variable-node circuit includes a threshold-tracking circuit which is configured to track a threshold used by the variable-node circuit during a low-density parity check (LDPC) decoding process to determine whether the variable-node circuit has entered a trapping status. In response to determining that the variable-node circuit has entered the trapping status during the LDPC decoding process, the variable-node circuit switches a bit-flipping algorithm used by the variable-node circuit during the LDPC decoding process from a first flipping strategy to a post-processing flipping strategy to bring the variable-node circuit out of the trapping status. The first flipping strategy is different from the post-processing flipping strategy.

A method of correcting data stored in a memory device includes: applying an iterative decoder to the data; determining a total number of rows in first data the decoder attempted to correct; estimating first visible error rows among the total number that continue to have an error after the attempt; estimating residual error rows among the total number that no longer have an error after the attempt; determining second visible error rows in second data of the decoder that continue to have an error by permuting indices of the residual error rows according to a permutation; and correcting the first data using the first visible error rows.

Devices, methods and computer programs for accelerating low-density parity-check (LDPC) decoding via scheduling are disclosed. At least some of the example embodiments described herein may allow reducing cost and improving power efficiency beyond that of semiconductor processor scaling currently used in accelerating LDPC decoding.

Devices, methods and computer programs for accelerating low-density parity-check (LDPC) decoding via scheduling are disclosed. At least some of the example embodiments described herein may allow reducing cost and improving power efficiency beyond that of semiconductor processor scaling currently used in accelerating LDPC decoding.

Post-processing circuitry for LDPC decoding includes check node processor for processing shifted LLR values, a hard decision decoder circuitry for receiving processed LLR information and performing parity checks on the processed LLR information. Post-processing control circuitry controls updating of LLR information in the check node processor. The check node processor, hard decision decoder, and control circuitry cooperate to identify check nodes with unsatisfied parity checks after an iteration cycle, identify neighborhood variable nodes that are connected with unsatisfied check nodes, identify satisfied check nodes which are connected to neighborhood variable nodes, and modify messages from neighborhood variable nodes to satisfied check nodes if needed to introduce perturbations to resolve decoding errors. Neighborhood identification circuitry determines which variable nodes are connected with unsatisfied check nodes, that have failed a parity check, and produces a signal indicating which variable nodes are connected to unsatisfied check nodes.

Post-processing circuitry for LDPC decoding includes check node processor for processing shifted LLR values, a hard decision decoder circuitry for receiving processed LLR information and performing parity checks on the processed LLR information. Post-processing control circuitry controls updating of LLR information in the check node processor. The check node processor, hard decision decoder, and control circuitry cooperate to identify check nodes with unsatisfied parity checks after an iteration cycle, identify neighborhood variable nodes that are connected with unsatisfied check nodes, identify satisfied check nodes which are connected to neighborhood variable nodes, and modify messages from neighborhood variable nodes to satisfied check nodes if needed to introduce perturbations to resolve decoding errors. Neighborhood identification circuitry determines which variable nodes are connected with unsatisfied check nodes, that have failed a parity check, and produces a signal indicating which variable nodes are connected to unsatisfied check nodes.