In one embodiment, a method includes writing data to a storage medium, via a write channel, by applying a partial reverse concatenated modulation code to the data prior to storing encoded data to the storage medium. The applying the partial reverse concatenated modulation code to the data includes application of a C2 encoding scheme to the data to produce C2-encoded data prior to application of one or more modulation encoding schemes to the C2-encoded data to produce modulated data, followed by application of a C1 encoding scheme to the modulated data subsequent to the application of the one or more modulation encoding schemes to produce the encoded data.

In one embodiment, an apparatus includes a controller and logic integrated with and/or executable by the controller. The logic is configured to perform track-dependent erasure decoding on encoded data based on detection of one or more time-varying signal quality issues associated with at least one of a plurality of tracks read simultaneously from a data storage medium. In another embodiment, a method includes determining, by a magnetic tape drive, track signal quality reliability for a plurality of tracks read simultaneously from a magnetic tape medium. In addition, the method includes performing, by the magnetic tape drive, track-dependent erasure decoding on encoded data based on detection of one or more time-varying signal quality issues associated with at least one of the plurality of simultaneously-read tracks.

In an optical disc apparatus that records and reproduces data onto and from an optical disc in units of predetermined block, an information divider divides the data so as to reduce an amount of the data included in each of blocks when a recording state of the optical disc does not satisfy a predetermined criterion, and reproduces recording data in units of the block by adding sub-information including a value indicating the amount of the data included in each of the blocks. An error-correction encoder circuit encodes the recording data in a first error-correction code format, and a recorder converts encoded recording data into a recording signal, and records the recording signal onto the optical disc. A quality evaluator circuit produces an evaluation value indicating a recording quality based on a result of reproducing the recording signal recorded on the optical disc.

Systems and methods are disclosed for performing segment-based outer code recovery at a data storage device. An apparatus may comprise a circuit configured to disable outer code error recovery, and perform a read operation spanning a plurality of segments of a data storage medium, a segment including a plurality of sectors. The circuit may identify one or more segments from the plurality of segments that have one or more sectors with an error. For an identified segment of the one or more segments, the circuit may perform a re-read operation with outer code error recovery enabled, and perform outer code recovery on sectors with an error within the identified segment.

In one embodiment, a system includes a processor configured to execute logic, the logic being configured to read a plurality of data sets, each data set including a plurality of portions which combine together to wholly form the data set, and reread at least a first uncorrected data set using a different setting in an error recovery procedure (ERP) when an error in the first uncorrected data set is not correctable using C2-ECC or an error in any portion of the first uncorrected data set is not correctable using C1-ECC. Other systems and methods for reading data from tape using a reconstructive ERP to reduce backhitches are presented according to more embodiments.

In an optical disc apparatus that records and reproduces data onto and from an optical disc in units of predetermined block, an information divider divides the data so as to reduce an amount of the data included in each of blocks when a recording state of the optical disc does not satisfy a predetermined criterion, and reproduces recording data in units of the block by adding sub-information including a value indicating the amount of the data included in each of the blocks. An error-correction encoder circuit encodes the recording data in a first error-correction code format, and a recorder converts encoded recording data into a recording signal, and records the recording signal onto the optical disc. A quality evaluator circuit produces an evaluation value indicating a recording quality based on a result of reproducing the recording signal recorded on the optical disc.

In one embodiment, an apparatus includes a controller and logic integrated with and/or executable by the controller. The logic is configured to perform track-dependent erasure decoding on encoded data based on detection of one or more time-varying signal quality issues associated with at least one of a plurality of tracks read simultaneously from a data storage medium. In another embodiment, a method includes determining, by a magnetic tape drive, track signal quality reliability for a plurality of tracks read simultaneously from a magnetic tape medium. In addition, the method includes performing, by the magnetic tape drive, track-dependent erasure decoding on encoded data based on detection of one or more time-varying signal quality issues associated with at least one of the plurality of simultaneously-read tracks.

In one embodiment, a method includes reading, using a plurality of read sensors of a magnetic head in a read channel of a tape drive, encoded data from a plurality of tracks of a magnetic tape medium simultaneously. Also, the method includes monitoring statistics for the read channel, the statistics monitored for the read channel including exponentially averaged mean squared error (MSE) or signal-to-noise ratio (SNR) for each simultaneously read track. Moreover, the method includes performing track-dependent erasure decoding on the encoded data based on detection of one or more time-varying signal quality issues associated with at least one of the plurality of tracks read simultaneously from the magnetic tape medium. The one or more time-varying signal quality issues are determined based on side information about reliability of detected bytes within C1 codewords of each simultaneously-read track.

In one embodiment, a method includes reading, using a plurality of read sensors of a magnetic head in a read channel of a tape drive, encoded data from a plurality of tracks of a magnetic tape medium simultaneously. Also, the method includes monitoring statistics for the read channel, the statistics monitored for the read channel including exponentially averaged mean squared error (MSE) or signal-to-noise ratio (SNR) for each simultaneously read track. Moreover, the method includes performing track-dependent erasure decoding on the encoded data based on detection of one or more time-varying signal quality issues associated with at least one of the plurality of tracks read simultaneously from the magnetic tape medium. The one or more time-varying signal quality issues are determined based on side information about reliability of detected bytes within C1 codewords of each simultaneously-read track.

[Object] To provide a receiving device capable of exhibiting the maximum recovery performance by the minimum processing in the two-dimensional FEC encoding method. [Solution] There is provided a decoding device, including: a decoding determination unit configured to determine a procedure of recovering and decoding missing packets in consideration of a packet missing pattern in data including a set of media packets and redundant packets generated by a two-dimensional XOR-based FEC encoding method; and a decoding unit configured to execute the recovery of the missing packets according to the procedure determined by the decoding determination unit.