The present disclosure generally relates to improving data transfer in a data storage device. In double data rate (DDR) systems that include a data bus inversion (DBI) functionality, bit flip events can be more prevalent. To mitigate the effect of enhanced erroneous bit flip rate related to DBI bit flip events, the DBI bit can stay static for a predetermined number of consecutive clock cycles, the error correction module can be informed of reduced reliability due to active DBI bit events, the DBI bit can be set to 0, or combinations thereof. Setting the DBI bit to 0 effectively cancels DBI functionality. Informing the error correction module permits a more robust error correction to occur. Forcing the DBI bit to remain static reduces the probability of an unrecognized bit flip event of a full byte. In so doing, data transfer reliability is improved when using DBI functionality.

Example systems, read channel circuits, data storage devices, and methods to provide signal correction based on soft information in a read channel are described. The read channel circuit includes a soft output detector, such as a soft output Viterbi algorithm (SOVA) detector, and a signal correction circuit. The soft output detector passes detected data bits and corresponding soft information to the signal correction circuit. The signal correction circuit uses the soft information to determine a signal correction value, which is combined with input signal to return a corrected signal to the soft output detector for a next iteration. In some configurations, the signal correction value may compensate for DC offset, AC coupling poles, and/or signal asymmetries to reduce baseline wander in the read channel.

An operation method of a receiving node may include performing a decoding operation for calculating first and second output transform values corresponding to first and second unit output nodes in each of a plurality of operation units constituting the polar decoder, based on first and second input transform values corresponding to first and second unit input nodes, and the decoding operation may include setting initial values of first and second variables for calculating the first output transform value; performing an iterative loop operation for updating the first and second variables; and calculating the first output transform value based on values of the first and second variables updated until a time when the iterative loop operation is terminated, wherein the iterative loop operation is terminated without performing iterations in which the first and second variables are determined not to be updated among a plurality of iterations.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a base station, a physical downlink shared channel (PDSCH) transmission in one or more of a half-duplexing mode or a full-duplexing mode. The UE may attempt to decode the PDSCH transmission using a low-density parity-check (LDPC) decoder. The UE may transmit, to the base station, feedback that indicates a difference between a half-duplex channel quality and a full-duplex channel quality based at least in part on one or more decoding parameters associated with the LDPC decoder. Numerous other aspects are described.

A channel decoding method is provided. The method includes storing, in a memory, a set of first log likelihood ratio (LLR) values corresponding to bits of a codeword generated by modulation of a channel-encoded signal; changing, into a preset value, at least one LLR value corresponding to previously defined bits of the codeword from among the set of the first LLR values, to generate a set of second LLR values; and performing forward error correction (FEC) based on the set of the second LLR values and an FEC code, to estimate the bits of the codeword, in which the FEC code comprises a constraint code for constricting a previously defined structural correlation between the bits of the codeword.

A decoder circuit includes first and second decoders. The first decoder is a first type of decoder configured to receive data encoded with an error correction code and decode and eliminate errors from a first subset of codewords of the data. The second decoder is a second type of decoder configured receive the data encoded with the error correction code and decode and eliminate errors from a second subset of codewords of the data, different from the first subset of the codewords, without attempting to decode and eliminate errors from the first subset of the codewords.

A decoding method includes: receiving a plurality of subcarrier signals each including encoded data; acquiring a predetermined amount of data from each of the plurality of subcarrier signals; correcting errors in the plurality of subcarrier signals by performing decoding arithmetic processing on the respective predetermined amounts of data acquired from the plurality of subcarrier signals in a time-division manner; and causing the decoding arithmetic processing to be consecutively performed on each of the predetermined amounts of data a predetermined number of times.

A method includes obtaining, for each type of nucleotide, a probability density function, the probability density functions being obtained from measurements of current drops produced during at least one passage of at least one sequence of reference nucleotides through a nanopore sequencer; obtaining measurements of current drops produced when the sequence of nucleotides to be decoded passes through the nanopore sequencer; calculating, for each measurement value considered and for each type of nucleotide of the B types of nucleotides, a piece of reliability information based on the probability density function obtained for the type of nucleotide considered; obtaining a decoded value identifying a type of nucleotide from the B types of DNA nucleotides, by applying a soft decoding algorithm with an error correction code to the current drop measurement and to the B pieces of reliability information obtained for the considered measurement value.

The present disclosure includes apparatus, systems, and techniques relating to noise-predictive detector adaptation. A described technique includes operating a decoder system to decode codewords that are based on a received encoded signal by processing the codewords and exchanging information between path and code decoders, operating the path decoder to use estimation parameters to produce first and second paths based on a codeword of the codewords, operating the code decoder to produce a decoded path based on the codeword; determining a winning path of first and second paths based on whether the decoded path matches the first path or the second path; and updating, based on one or more error terms and the winning path, the estimation parameters to favor selection of the winning path by the path decoder and to disfavor selection of a losing path of the first and second paths by the path decoder.

Example systems, read channel circuits, data storage devices, and methods to use inter-symbol interference message passing (ISI-MP) data in a read channel are described. The read channel circuit includes a soft output detector, such as a soft output Viterbi algorithm (SOVA) detector, configured to determine both the first most likely and second most likely sets of symbols and output inter-symbol interference data based on the adjacent symbols and corresponding ISI in each set of symbols. The inter-symbol interference data may be used by an ISI-MP circuit configured to model ISI-MP and provide feedback to an iterative decoder during local iterations.