Lsi Corporation

Avago Technologies General IP (singapore) Pte. Ltd.

Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Avago Technologies International Sales Pte. Limited

Jongseung Park

George Mathew

Erich Franz Haratsch

Shaohua Yang

Bruce Alexander Wilson

Yuan Xing Lee

Ming Jin

Richard Rauschmayer

Richard Leo Galbraith

Travis Roger Oenning

Hideki Sawaguchi

Ksenija Lakovic

Timothy B Lund

Hongwei Song

Andrei Vityaev

Carl E Forhan

Timothy W Swatosh

Ivana Djurdjevic

Eui Seok Hwang

Fan Zhang

Mario Blaum

Jingfeng Liu

Jun Xiao

Jefferson E Singleton

Alan D Poeppelman

Li Du

Kurt J Worrell

Han Fang

Liu Jingfeng

A data processing system is disclosed including a data detector, a data decoder and an alignment detector. The data detector is operable to apply a data detection algorithm to generate detected values for a data sector. The data decoder is operable to apply a data decode algorithm to a decoder input derived from the detected values to yield decoded values. The alignment detector is operable to calculate an offset between multiple versions of the data sector by correlating the multiple versions.

Systems and methods for correlation based data alignment

An apparatus for two-dimensional magnetic recording includes an array reader comprising a number of read sensors configured to read data from at least one track on a storage medium, a number of two-dimensional equalizer circuits each comprising inputs for receiving signals derived from each of the read sensors, each comprising an equalized output, and a number of iterative inter-track interference cancellation circuits, each operable to cancel inter-track interference in a different one of the equalized outputs from the two-dimensional equalizer circuits.

Multi-track data readers with iterative inter-track interference cancellation

Systems and methods are disclosed for data processing, and more particularly for equalizing a data signal during both real time (i.e., on the fly) and retry operation. The system may include a first equalizer circuit operable to equalize a first sample set, and a second equalizer circuit operable to equalize a second sample set. The system may include a third equalizer circuit operable to equalize a summed data set to yield a third equalized output. The system may include a summation circuit connected to the first equalizer circuit, the second equalizer circuit, and a switch circuit. The summation circuit is operable to sum at least the first equalized data set and the second equalized data set to yield the summed data set. The switch circuit selectively provides the third equalized data set to the summation circuit.

Magnetic recording system for real time and retry multi-dimensional signal equalization

Embodiments are related to systems and methods for data processing, and more particularly to systems and methods for multi-dimensional signal equalization. In one case, a data processing system is discussed that includes: a first equalizer governed at least in part by a first coefficient; a second equalizer circuit governed at least in part by a second coefficient; and a constraint circuit operable to force a sum of at least the first coefficient and the second coefficient to equal a defined value.

Systems and methods for multi-dimensional equalization constraint

A method of mitigating an effect of track misregistration on read performance in a system comprising an array-reader includes determining an estimated off-track condition, selecting translation coefficients based on the estimated off-track condition, determining updated equalizer coefficients by applying the translation coefficients to native equalizer coefficients, and applying the updated equalizer coefficients to signals received from the array-reader to output a read signal.

Track misregistration sensitive initialization of joint equalizer

An apparatus for reading data includes an array of analog inputs operable to receive analog signals retrieved from a magnetic storage medium, wherein the analog inputs correspond to multiple data tracks on the magnetic storage medium, and wherein the number of analog inputs in the array of analog inputs is greater than the number of data tracks being read, at least one joint equalizer operable to filter the analog inputs to yield an equalized output for each of the data tracks being read, and at least one data detector operable to apply a detection algorithm to the equalized output from the joint equalizer to yield detected values for each of the data tracks being read.

Multiple track detection

Systems, methods, devices, circuits for data processing, and more particularly to systems and methods for reducing inter-track interference in relation to processing data retrieved from a storage medium.

Systems and methods for data dependent inter-track interference cancellation

Hardware-based methods and apparatus are provided for inter-track interference mitigation in magnetic recording systems using averaged values. Inter-track interference (ITI) is mitigated in a magnetic recording system by obtaining ITI cancellation data; and providing the ITI cancellation data for ITI mitigation, wherein the ITI mitigation is performed in combination with an averaging procedure for one or more of ITI mitigation of averaged data and averaging of ITI mitigated data. The sector is optionally decoded using the ITI mitigated samples. Samples for one or more side track sectors can also be averaged. The averaged side track samples can be provided as ITI cancellation data for ITI mitigation. The averaging procedure optionally applies a scaling factor to each read value.

Inter-track interference mitigation in magnetic recording systems using averaged values

Described embodiments provide a method of cancelling inter-track interference (ITI) from one or more sectors read from a desired track of a storage medium. A road channel reads sectors in a desired track of the storage medium. A decoder of the read channel decodes the read sectors, and if the read sectors are incorrectly recovered from the storage medium, selected sectors of a first adjacent track and a second adjacent track are read. An ITI canceller of the read channel estimates ITI in the read sectors of the desired track corresponding to the selected sectors of each adjacent track and subtracts the estimated ITI of each adjacent track from the data for the sectors of the desired track, providing updated sector data. The ITI cancelled data is replayed to the decoder, which decodes the ITI cancelled data and provides the decoded ITI cancelled data as output of the read channel.

Storage media inter-track interference cancellation

Systems, methods, devices, circuits for data processing, and more particularly to systems and methods for adapting noise predictive filters for inter-track interference cancellation in a data processing system.

Noise predictive filter adaptation for inter-track interference cancellation

Systems and methods for data processing, and more particularly to estimating or calculating interference between tracks on a storage medium.

Systems and methods for old data inter-track interference compensation

Embodiments are related to systems and methods for data processing, and more particularly to systems and methods for equalizing a data signal.

Systems and methods for multi-dimensional signal equalization

Described embodiments provide a method of cancelling inter-track interference (ITI) from one or more sectors read from a desired track of a storage medium. A read channel reads sectors in a desired track of the storage medium. An iterative decoder of the read channel decodes the read sectors, and if the read sectors are incorrectly recovered from the storage medium, selected sectors of a first adjacent track are read. An ITI canceller of the read channel estimates ITI in the read sectors of the desired track corresponding to the selected sectors of the adjacent track and subtracts the estimated ITI of the adjacent track from the data for the sectors of the desired track, providing updated sector data. The ITI cancelled data is replayed to the iterative decoder, which decodes the ITI cancelled data and provides the decoded ITI cancelled data as output data of the read channel.

Various embodiments of the present invention provide systems and methods for data processing. As an example, a data processing circuit is discussed that includes: a data buffer, an inter-track interference response circuit, and an inter-track interference signal estimator circuit. The data buffer is operable to store a previous track data set. The inter-track interference response circuit is operable to estimate an inter-track interference response from the previous track data set based at least in part on the previous track data set and a current track data set. The inter-track interference signal estimator circuit is operable to calculate an inter-track interference from the previous track data set based at least in part on the previous track data set and the inter-track interference response from the previous track data set.

Systems and methods for inter-track interference compensation

Various embodiments of the present invention provide systems and methods for data processing. As an example, a block-wise data processing circuit is discussed that includes: a data buffer, an inter-track interference response circuit, and an inter-track interference signal estimator circuit. The data buffer is operable to store a previous track data set corresponding to a block. The inter-track interference response circuit is operable to estimate an inter-track interference response from the previous track data set across the block based at least in part on the previous track data set and a current track data set. The inter-track interference signal estimator circuit is operable to calculate an inter-track interference from the previous track data set across the block based at least in part on the previous track data set and the inter-track interference response from the previous track data set.

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Allentown, PA, United States of America

Jongseung Park