摘要:
Various embodiments of the present invention provide systems and methods for data processing. A data processing circuit is disclosed that includes: a data detector circuit, a first symbol constrained arrangement circuit, and a second symbol constrained arrangement circuit. The data detector circuit is operable to apply a data detection algorithm to a combination of a first input data set and a decoded data set to yield a detected output that includes a number of non-binary symbols. The first symbol constrained arrangement circuit is operable to receive the detected output and to re-arrange the detected output in accordance with a first arrangement algorithm to yield a re-arranged output. The bits for at least one non-binary symbol from the detected output are maintained together in the re-arranged output. The second symbol constrained arrangement circuit is operable to receive a second input data set and to re-arrange the second data input in accordance with a second arrangement algorithm to yield the decoded data set. The bits for at least one non-binary symbol from the second input data set are maintained together in the decoded data set output.
摘要:
Various embodiments of the present invention provide systems and methods for data processing. A data processing circuit is disclosed that includes: a data detector circuit, a first symbol constrained arrangement circuit, and a second symbol constrained arrangement circuit. The data detector circuit is operable to apply a data detection algorithm to a combination of a first input data set and a decoded data set to yield a detected output that includes a number of non-binary symbols. The first symbol constrained arrangement circuit is operable to receive the detected output and to re-arrange the detected output in accordance with a first arrangement algorithm to yield a re-arranged output. The bits for at least one non-binary symbol from the detected output are maintained together in the re-arranged output. The second symbol constrained arrangement circuit is operable to receive a second input data set and to re-arrange the second data input in accordance with a second arrangement algorithm to yield the decoded data set. The bits for at least one non-binary symbol from the second input data set are maintained together in the decoded data set output.
摘要:
Various embodiments of the present invention provide systems and methods for data processing. For example, a variable iteration data processing system is disclosed that includes a first detector, a second detector, a decoder and a unified memory buffer. An input data set is received by the first detector that performs a data detection and provides a first detected data set. The decoder receives a derivative of the first detected data set and performs a decoding operation that yields a decoded data set. In some cases, the derivative of the first detected data set is an interleaved version of the first detected data set. The decoded data set is written to a unified memory buffer. The first decoded data set is retrievable from the unified memory buffer and a derivative thereof is provided to the second detector. In some cases, the derivative of the decoded is a de-interleaved version of the decoded data set. The second detector is operable to perform a data detection on the derivative of the decoded data set and to provide a second detected data set that is written to the unified memory buffer.
摘要:
In exemplary embodiments, a skewed interleaving function for iterative code systems is described. The skewed interleaving function provides a skewed row and column memory partition and a layered structure for re-arranging data samples read from, for example, a first channel detector. An iterative decoder, such as an iterative decoder based on a low-density parity-check code (LDPC), might employ an element to de-skew the data from the interleaved memory partition before performing iterative decoding of the data, and then re-skew the information before passing decoded samples to the de-interleaver. The de-interleaver re-arranges the iterative decoded data samples in accordance with an inverse of the interleaver function before passing the decoded data samples to, for example, a second channel detector.
摘要:
Various embodiments of the present invention provide systems and methods for data processing. For example, a data processing system is disclosed that includes a processing loop circuit having a data detector and a soft decision decoder. The data detector provides a detected output, and the soft decision decoder applies a soft decoding algorithm to a derivative of the detected output to yield a soft decision output and a first hard decision output. The systems further include a queuing buffer and a hard decision decoder. The queuing buffer is operable to store the soft decision output, and the hard decision decoder accesses the soft decision output and applies a hard decoding algorithm to yield a second hard decision output. The data detector is operable to perform a data detection on a derivative of the soft decision output if the soft decision decoder and the hard decision decoder fail to converge
摘要:
In one embodiment, a turbo equalizer has an LDPC decoder, a channel detector, and one or more adjustment blocks for recovering an LDPC codeword from a set of input samples. The decoder attempts to recover the codeword from an initial set of channel soft-output values and generates a set of extrinsic soft-output values, each corresponding to a bit of the codeword. If the decoder converges on a trapping set, then the channel detector performs detection on the set of input samples to generate a set of updated channel soft-output values, using the extrinsic soft-output values to improve the detection. The one or more adjustment blocks adjust at least one of (i) the extrinsic soft-output values before the channel detection and (ii) the updated channel soft-output values. Subsequent decoding is then performed on the updated and possibly-adjusted channel soft-output values to attempt to recover the codeword.
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 data detector circuit, a data decoder circuit, and a gating circuit.
摘要:
Hardware-based methods and apparatus are provided for inter-track interference mitigation in magnetic recording systems. Inter-track interference (ITI) is mitigated in a magnetic recording system by obtaining ITI cancellation data; and providing the ITI cancellation data to an ITI mitigation circuit using a write data path in the magnetic recording system. The write data path can optionally operate substantially simultaneously with the read data path performing the read operation. The ITI cancellation data comprises, for example, user data and/or media data.
摘要:
Various embodiments of the present invention provide systems and methods for decoding of non-binary LDPC codes. For example, a low density parity check data decoder is disclosed that includes a variable node processor operable to perform variable node updates based at least in part on check node to variable node message vectors, a check node processor operable to perform check node updates and to generate the check node to variable node message vectors, and a scheduler operable to cause the variable node processor to use check node to variable node message vectors from multiple decoding iterations when performing the variable node updates for a given decoding iteration.
摘要:
Various embodiments of the present inventions are related to adaptive calibration of NPFIR filters in a data detector. For example, an apparatus for calibrating a noise predictive filter is disclosed, including a data detector operable to generate detected values for data sectors and having an embedded noise predictive finite impulse response filter. The apparatus also includes a comparator operable to determine whether a quality metric for a current one of the data sectors meets a noise threshold. The apparatus also includes a filter calibration circuit operable to adapt a number of filter coefficients for the noise predictive finite impulse response filter based on the detected values for the data sectors, and to omit the detected values for the current one of the data sectors from adaptation for one of the filter coefficients if the quality metric for the current one of the data sectors does not meet the noise threshold.