Provided is a coding control method in a passive optical network (PON). The method includes acquiring data of a service to be coded and a preset codeword length N corresponding to the service to be coded; acquiring a coding mode corresponding to the preset codeword length N in a preset table describing a correspondence between codeword length ranges and coding modes; and coding data of the service by using the coding mode corresponding to the preset codeword length N. Further provided are a coding control apparatus in a PON, a communication device and a storage medium.

An LDPC code encoding method and a communication apparatus are described that provide increased redundant bits through retransmission in an IR-HARQ mechanism, so as to decrease a channel coding rate, and improve decoding performance of an LDPC code. A check matrix of the LDPC code is used as a basic matrix, and the basic matrix is extended to obtain a mother matrix compatible with a plurality of code rates. During LDPC encoding, a transmit device reads, from the mother matrix, a check matrix corresponding to a required code rate, and performs LDPC encoding on an information bit sequence based on the read check matrix. LDPC encoding is performed on the information bit sequence by using check matrices of different sizes, to obtain different quantities of redundant bits.

The present disclosure relates to a method, system, and non-transitory computer-readable storage medium for constructing a base matrix of a PBRL LDPC code, comprising: determining at least one candidate sub-matrix of a PBRL LDPC code based on a base matrix of a QR-QC-LDPC code; obtaining at least one count of cycles with at least one preset length for each of the at least one candidate sub-matrix; and determining a first sub-matrix of the base matrix of the PBRL LDPC code based on the at least one count of cycles.

Systems and methods are provided for performing error recovery using LLRs generated from multi-read operations. A method may comprise selecting a set of decoding factors for a multi-read operation to read a non-volatile storage device multiple times. The set of decoding factors may include an aggregation mode for aggregating read results of multiple reads. The method may further comprise issuing a command to the non-volatile storage device to read user data according to the set of decoding factors, generating a plurality of Log-Likelihood Ratio (LLR) values using a mapping engine from a pre-selected set of LLR value magnitudes based on the set of decoding factors, obtaining an aggregated read result in accordance with the aggregation mode and obtaining an LLR value from the plurality of LLR values using the aggregated read result as an index.

Various implementations described herein relate to systems and methods for decoding data stored in a non-volatile storage device, including determining error candidates and determining whether at least one first error candidate from the error candidates is found based on two of the component codes agreeing on a same error candidate. In addition, whether at least one second error candidate is found based on two of the component codes agreeing on a same error candidate is determined in response to implementing a suggested correction at one of the error candidates. Errors in the data are corrected based on at least one of whether the at least one first error candidate is found or whether the at least one second error candidate is found.

A bit interleaver, a bit-interleaved coded modulation (BICM) device and a bit interleaving method are disclosed herein. The bit interleaver includes a first memory, a processor, and a second memory. The first memory stores a low-density parity check (LDPC) codeword having a length of 64800 and a code rate of 3/15. The processor generates an interleaved codeword by interleaving the LDPC codeword on a bit group basis. The size of the bit group corresponds to a parallel factor of the LDPC codeword. The second memory provides the interleaved codeword to a modulator for 256-symbol mapping.

A low density parity check (LDPC) channel encoding method is used in a wireless communications system. A communication device encodes an input bit sequence by using an LDPC matrix, to obtain an encoded bit sequence for transmission. The LDPC matrix is obtained based on a lifting factor Z and a base matrix. The base matrix may be one of eight exemplary designs. The encoding method can be used in various communications systems including fifth generation (5G) telecommunication systems, and can support various encoding requirements for information bit sequences with different code lengths.

A memory system includes a semiconductor storage device and a memory controller including a storage circuit that stores correction value for read voltages in association with the word line, and a control circuit that reads data from the memory cells, performs a correction operation on the read data to determine a number of error bits therein, determines the correction value for each read voltage based on the number of error bits and a ratio of a lower tail fail bit count and an upper tail fail bit count, and stores the correction values for the read voltages in the storage circuit. The lower tail fail bit count represents the number of memory cells in a first state having threshold voltages of an adjacent state, and the upper tail fail bit count represents the number of memory cells in the adjacent state having threshold voltages of the first state.

An exemplary method for reading data stored in a flash memory includes: selecting an initial gate voltage combination from a plurality of predetermined gate voltage combination options; controlling a plurality of memory units in the flash memory according to the initial gate voltage combination, and reading a plurality of bit sequences; performing a codeword error correction upon the plurality of bit sequences, and determining if the codeword error correction successful; if the codeword error correction is not successful, determining an electric charge distribution parameter; determining a target gate voltage combination corresponding to the electric charge distribution parameter by using a look-up table; and controlling the plurality of memory units to read a plurality of updated bit sequences according to the target gate voltage combination.

Techniques for performing forward error correction of data to be transmitted over an optical communications channel. The techniques include: receiving data bits; organizing the data bits into an arrangement having a plurality of blocks organized into rows and columns and into a plurality of strands including a first strand of blocks that includes a back portion comprising a first row of the plurality of blocks, and a front portion comprising blocks from at least two different columns in at least two different rows other than the first row of blocks; and encoding at least some of the data bits in the arrangement using a first error correcting code at least in part by generating first parity bits by applying the first error correcting code to first data bits in the front portion of the first strands and second data bits in the back portion of the first strand.