Seagate Technology Incorporated

Alexander Kuznetsov

Erozan Mehmet Kurtas

Xueshi Yang

Bane Vasic

Ara Patapoutian

Mehmet Fatih Erden

Kinhing Paul Tsang

Raman Venkataramani

Cenk Argon

In a particular embodiment, a channel detector is disclosed that includes a programmable look-up table (LUT) to relate user bits to channel bits. The programmable LUT is adapted to be implemented on a state trellis of arbitrary radix. The channel detector further includes a sectional precoder coupled to a channel and having access to the programmable LUT. The sectional precoder is adapted to map channel bits to user bits and vice versa using a programmable LUT.

Programmable soft-output Viterbi algorithm system and method

A method of writing data on a storage medium that takes into account a condition of the storage medium. The method includes receiving data to be written on a portion of a storage medium and encoding the data based on a condition of the portion of the storage medium. The encoded data is written on the portion of the storage medium. A data storage system that includes a storage medium having defects is also provided. The data storage system utilizes a coding scheme that comprises coding bit patterns configured to address the defects on the storage medium.

Coding technique for correcting media defect-related errors and random errors

A system includes an encoder that manipulates postcoded data and produces parity bits, and a parity bit encoder that produces encoded parity bits by inserting into the parity bits one or more flags with polarities, or states, that are selected to produce, after precoding, precoded parity bits that meet predetermined modulation constraints.

System for precoding parity bits to meet predetermined modulation constraints

Iterative decoding channel architectures employing coded modulation are provided. The coded modulation is realized via set partitioning for Partial Response (PR) channels along with multi-level coding. Associated error correction encoding and decoding methods, with additional compatibility considerations for channel constrained coding, are also provided.

Iterative read channel architectures with coded modulation

A method of determining errors in a data storage device is disclosed. The disclosed method includes receiving a first code word from the data storage device. The method further includes determining whether a data error exists in the code word by analyzing a plurality of subsequent code words. Detecting a data error includes calculating first, second, and third checksums for each of a plurality of subsequent code words and determining whether there is an insertion or deletion error based on the calculated checksums. A further method includes receiving location information of errors on a data medium and adjusting a write clock frequency to reduce the probability of creating errors on the data medium during a write process.

Detecting and correcting insertion and deletion of bits for bit patterned media storage systems

A method and apparatus for channel coding useful for recording channel and other communications applications. The proposed channel coding method is actualized via structured set partition (SSP) in conjunction with multilevel coding (MLC) and offers performance gains over conventional coding schemes with comparable complexity at the bit-error rate (BER) level as well as the sector failure rate (SFR) level.

Structured set partitioning and multilevel coding for partial response channels

A method of additive encoding of data words includes receiving a plurality of data words, and searching a trellis representation of additive code words to identify a path in the trellis representing a sequence of patterns to be used to encode the data words. The trellis representation is of all possible combinations of matching patterns in a sequence of additive code words. The trellis representation of the additive code words is searched to identify a sequence of flags representing the sequence of patterns to be used to encode the data words.

Method and apparatus for additive trellis encoding

A method of generating low density parity check codes for encoding data includes constructing a parity check matrix H from balanced incomplete block design (BIBD) in which a plurality B-sets which define the matrix have no more than one intersection point. The parity bits are then generated as a function of the constructed parity check matrix H.

Method and coding apparatus using low density parity check codes for data storage or data transmission

A system and method of forming RLL coded data streams with separator blocks has an RLL encoder and a channel encoder. The input code word is divided into data portions and a separator portion. The data portions are inserted into an output codeword without encoding. Each data portion is separated from a next data portion by a space. The separator portion is encoded into non-zero separator sub-matrices, which are stuffed into the spaces between the data portions. The separator portions and the data portions may be separately permuted without exceeding a maximum number of consecutive zeros.

Method and apparatus for coded symbol stuffing in recording systems

The present invention provides a novel method and apparatus for decoding digital information transmitted through the communication channel or recorded on a recording medium. The method and apparatus are preferably applied in the systems where data is encoded using regular LDPC codes with parity check matrices composed from circulants (a matrix is called a circulant if all its column or row are cyclic shifts each other).

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Pittsburgh, PA, United States of America

Alexander Kuznetsov