摘要:
The present inventions are related to systems and methods for calculating data quality metrics for an LDPC decoder, and particularly for calculating a fractional unsatisfied check quality metric.
摘要:
An apparatus includes a low density parity check decoder operable to iteratively generate messages between a plurality of check nodes and variable nodes, and to calculate a fractional quality metric for a data block as it is decoded in the low density parity check decoder based at least in part on perceived values of data in the variable nodes. The fractional unsatisfied check quality metric is a probabilistic determination of a number of unsatisfied parity checks in the low density parity check decoder.
摘要:
A device includes a disk drive assembly configured to store information using a platter comprising a magnetic material surface and a magnetic head disposed above the magnetic material surface. The magnetic head is configured to move across tracks formed on the platter to write information to the magnetic material surface and read information from the magnetic material surface. The device also includes a controller operatively coupled with the disk drive assembly. The controller is configured to dynamically adjust the height of the magnetic head above the magnetic material surface at each of the tracks by determining a harmonic ratio for a particular track and comparing the harmonic ratio to a reference harmonic ratio for the track. For example, the controller calculates a difference between the harmonic ratio and the reference harmonic ratio.
摘要:
Various embodiments of the present invention provide systems and methods for media defect detection. Such systems and methods may include data pre-processing and detection to identify a media defect.
摘要:
The present invention is related to systems and methods for applying a data decode algorithm to different rotations or modifications of a decoder input as part of data processing.
摘要:
Various embodiments of the present invention provide systems and methods for data processing. As an example, a data processing circuit is disclosed that includes a noise injection circuit. The noise injection circuit is operable to: determine a difference between a first data output and a second data output to yield an error; and augment an interim data with a noise value corresponding to the error to yield a noise injected output. The interim data may be either the first data output or the second data output.
摘要:
A probabilistic approach of symbol error estimation is disclosed. The probabilistic approach of symbol error estimation reflects the number of symbol errors more precisely than the number of unsatisfied checks. The more precise quality metric calculated in accordance with the present disclosure allows a codec system to achieve a better overall performance. In addition, many other features that previously depend on the number of unsatisfied checks as the sector quality metric may also benefit by adopting the more precise quality metric.
摘要:
A probabilistic approach of symbol error estimation is disclosed. The probabilistic approach of symbol error estimation reflects the number of symbol errors more precisely than the number of unsatisfied checks. The more precise quality metric calculated in accordance with the present disclosure allows a codec system to achieve a better overall performance. In addition, many other features that previously depend on the number of unsatisfied checks as the sector quality metric may also benefit by adopting the more precise quality metric.
摘要:
A method and system for eliminating/suppressing long transition runs over a communications channel is disclosed. The method may include providing modulation coding based on a multi-level finite state machine (ML-FSM) having a periodic structure, the periodic structure being defined by a predetermined number of time frames. The ML-FSM may include a plurality of penalty-free edges for connecting nodes in one time frame to nodes at the same level in a subsequent time frame and a plurality of penalty edges for connecting nodes in one time frame to nodes at an upper level in the subsequent time frame. The method may further include utilizing the ML-FSM based modulation coding to facilitate data transmission over the communications channel.