Class / Patent application number | Description | Number of patent applications / Date published |
360045000 | Pulse crowding correction | 26 |
20120063022 | 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 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. | 03-15-2012 |
20120063023 | Systems and Methods for Block-wise 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. | 03-15-2012 |
20120105994 | INTER-TRACK INTERFERENCE CANCELATION FOR SHINGLED MAGNETIC RECORDING - Inter-track interference cancelation is disclosed, including: receiving an input sequence of samples associated with a track on magnetic storage; using a processor to generate inter-track interference (ITI) data associated with a first side track including by performing a correlation between the input sequence of samples and a sequence of data associated with the first side track. | 05-03-2012 |
20130021689 | STORAGE MEDIA INTER-TRACK INTERFERENCE CANCELLATION - 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. 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 ITT cancelled data and provides the decoded ITI cancelled data as output of the read channel. | 01-24-2013 |
20130083417 | Hardware-Based Methods And Apparatus For Inter-Track Interference Mitigation In Magnetic Recording Systems - 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. | 04-04-2013 |
20130083418 | HARDWARE-BASED INTER-TRACK INTERFERENCE MITIGATION IN MAGNETIC RECORDING SYSTEMS WITH READ CHANNEL STORAGE OF CANCELATION DATA - Hardware-based methods and apparatus are provided for inter-track interference mitigation in magnetic recording systems. Inter-track interference (ITI) cancellation data is stored in a memory of a read channel of a magnetic recording system. The memory can be in a write data path or a read data path of the read channel. The inter-track interference cancellation data is optionally provided to an inter-track interference mitigation circuit using at least a portion of a write data path, for example, based on a control signal. The storage of the inter-track interference cancellation data can be in response to a second control signal. | 04-04-2013 |
20130182348 | MAGNETIC DISK DRIVE AND DATA BUFFERING METHOD APPLIED TO THE SAME - According to one embodiment, there is provided a method of temporarily storing data in a buffer. The method determines whether data written based on sequential writing is of a first type or a second type in data type. The method stores the written data in association with the determined data type in the buffer. The method further controls the buffer so that the data of the first type stored in the buffer may be held in the buffer for a length of time twice as long as time T | 07-18-2013 |
20130286498 | INTER-TRACK INTERFERENCE MITIGATION IN MAGNETIC RECORDING SYSTEMS USING AVERAGED VALUES - 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. | 10-31-2013 |
20140078608 | Systems and Methods for Hard Decision Based ITI Cancellation - Embodiments of the present inventions are related to systems and methods 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. | 03-20-2014 |
20140104715 | DATA REPRODUCTION APPARATUS, DISK STORAGE APPARATUS AND METHOD FOR REPRODUCING DATA - According to one embodiment, a data reproduction apparatus includes a decoder, a cancellation process module and a calculator. The cancellation process module cancels, from equalized-waveform data of a read signal, the interference between a signal read from a first track and a signal read form a second track adjacent to the first track. The calculator calculates, for a specific window, a first cancellation coefficient necessary to cancel the interference. The calculator further calculates a second cancellation coefficient by correcting the first cancellation coefficient based on a ratio of the number of adjacent bits of opposite polarity to the number of all bits in the specific window. | 04-17-2014 |
20140146411 | METHOD FOR ADJUSTING LINEAR RECORDING DENSITY AND MAGNETIC DISK DRIVE - According to one embodiment, there is provided a method, implemented in a magnetic disk drive, for adjusting a linear recording density. The method obtains a first flying-dependent error sensitivity for each of two or more heads. The first flying-dependent error sensitivity represents a change in read error rate corresponding to a change in flying height of the head during write. In addition, the method reduces the linear recording density of a first recording surface associated with a first head of the two or more heads if the first flying-dependent error sensitivity is a second flying-dependent error sensitivity higher than a threshold and corresponds to the first head. | 05-29-2014 |
20140153126 | Systems and Methods for Old Data Inter-track Interference Compensation - Systems and methods for data processing, and more particularly to estimating or calculating interference between tracks on a storage medium. | 06-05-2014 |
20140160590 | DETECTING TRACK INFORMATION FROM OVERLAPPING SIGNALS READ FROM A DATA STORAGE MEDIUM - Detecting track information involves receiving first and second overlapping track signals from first and second read elements that read first and second tracks from a data storage medium. Information of the first and second tracks is estimated using the respective first and second track signals. An improved information estimate of the first track is obtained using the first track signal and the estimated information of the second track, and an improved information estimate of the second track is obtained using the second track signal and the estimated information of the first track. First and second track data are decoded using the respective improved information estimates of the first and second tracks. | 06-12-2014 |
20140192434 | INTER-TRACK INTERFERENCE CANCELATION FOR SHINGLED MAGNETIC RECORDING - Inter-track interference cancelation is disclosed, including: receiving an input sequence of samples associated with a track on magnetic storage; using a processor to generate inter-track interference (ITI) data associated with a first side track including by performing a correlation between the input sequence of samples and a sequence of data associated with the first side track. | 07-10-2014 |
20140247514 | Systems and Methods for ADC Sample Based Inter-track Interference Compensation - Various embodiments of the present invention provide systems and methods for mitigating inter-track interference using pre-equalized data samples. | 09-04-2014 |
20140268391 | DATA SEQUENCE DETECTION IN BAND-LIMITED CHANNELS USING COOPERATIVE SEQUENCE EQUALIZATION - A method for detecting a data sequence includes generating a sample stream, which is a time-sequenced digital signal associated with samples of an analog signal. The sample stream is input to n equalization filter banks, which each have m equalization filters to generate m equalized sample streams. The m equalized sample streams from each equalization filter bank are input to a corresponding one of n noise predictive filters. Each noise predictive filter is an m-tap noise predictive filter that receives the m equalized sample streams from a corresponding one of the n equalization filter banks. Each noise predictive filter is associated with one of n data patterns. A filtered equalization stream is generated by each noise predictive filter. Noise sample streams are generated using the filtered equalization streams generated by the n noise predictive filters. A data sequence is detected using the noise sample streams. | 09-18-2014 |
20140268392 | DATA DETECTION IN ADJACENT TRACKS - Devices and/or methods may detect data located in adjacent tracks. A signal representative of a first data unit having a higher signal-to-noise ratio may be detected prior to a signal representative of a second data unit having a lower signal-to-noise ratio, and then may be used to improve the signal representative of the second data unit. | 09-18-2014 |
20150015983 | SIZE ADJUSTABLE INTER-TRACK INTERFERENCE CANCELLATION - Technologies are described herein for cancelling inter-track interference in a storage device utilizing size-adjustable segments. Data is read from one or more sectors on a data track adjacent to a target sector on a target track of a recording medium of the storage device. The target sector is divided into a plurality of segments and data is decoded from the read signal read from each of the segments individually using corresponding data from the one or more sectors of the adjacent track and independent inter-track interference factor values. | 01-15-2015 |
20150015984 | Storage Media Inter-Track interference Cancellation - 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. 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 ITT cancelled data and provides the decoded ITI cancelled data as output of the read channel. | 01-15-2015 |
20150043098 | MULTI-SENSOR DATA TRANSDUCER - Method and apparatus for decoding data, such as from a rotatable magnetic recording medium. In accordance with some embodiments, a plurality of sensors is provided, with each sensor configured to generate a sense signal from an adjacent pattern. A processing circuit is configured to decode data from the adjacent pattern using the generated sense signals. | 02-12-2015 |
20150092289 | GENERATING POSITION ERROR SIGNAL BASED ON DATA TRACKS FOR MAGNETIC DATA STORAGE - A hard disk drive circuit includes first and second inter-track interference detection modules. The first inter-track interference detection module is configured to generate a first measured inter-track interference value based on a first read signal from a first read sensor positioned over a magnetic medium. The second inter-track interference detection module is configured to generate a second measured inter-track interference value based on a second read signal from a second read sensor positioned over the magnetic medium. A position error signal generation module is configured to generate a position error signal based on the first measured inter-track interference value and the second measured inter-track interference value. An arm control module is configured to control rotation of an arm in response to the position error signal. The first read sensor and the second read sensor are located at a distal end of the arm. | 04-02-2015 |
20160019931 | GENERATING POSITION ERROR SIGNAL BASED ON DATA TRACKS FOR ROTATING STORAGE DATA STORAGE - A system including an inter-track interference detection module and a position error signal generation module. The inter-track interference detection module determines a first inter-track interference value based on a first signal from a first sensor positioned over a first track of a rotating storage medium. The first inter-track interference value indicates energy contributed by tracks adjacent to the first track compared to energy contributed by the first track. The inter-track interference detection module determines a second inter-track interference value based on a second signal from a second sensor positioned over a second track of the rotating storage medium. The second inter-track interference value indicates energy contributed by tracks adjacent to the second track compared to energy contributed by the second track. The position error signal generation module generates a position error signal based on the first inter-track interference value and the second inter-track interference value. | 01-21-2016 |
20160035384 | SKEW-TOLERANT MULTIPLE-READER ARRAY IN ARRAY-READER BASED MAGNETIC RECORDING - A method for enhancing read performance in an ARMR system includes: obtaining CTS information for a plurality of readers in a multi-reader head of the ARMR system, the CTS information defining a relationship between skew angle and CTS between respective combinations of subsets of the readers; determining, as a function of the CTS information, a subset of the readers which provides enhanced read performance among the readers for each of a plurality of skew angles; assigning a weight value to each of a plurality of read signals generated by a corresponding one of the readers for each of the skew angles, the weight value being indicative of a performance of the corresponding one of the readers relative to one another; and decoding information read from at least one target track of a magnetic storage medium being read as a function of the read signals and corresponding weight values. | 02-04-2016 |
20160111125 | RECEPTION TERMINAL AND A METHOD FOR COMPENSATING INTER-SYMBOL INTERFERENCE AND COMPUTER READABLE RECORDING MEDIUM FOR PERFORMING THE SAME - A reception terminal and a method for compensating for inter-symbol interference (ISI) in a two-dimensional (2D) data structure are provided. The method for compensating for ISI includes transmitting, from a transmission terminal, a plurality of source pixel values based on a source 2D data structure via a channel, receiving, at a reception terminal, a plurality of pixel values for compensation based on a 2D data structure, and compensating each of the plurality of pixel values for compensation to each of corresponding pixel values after compensation. The plurality of pixel values for compensation are changed values of the pixel values of the source pixels due to the ISI, and each of the pixel values after compensation is determined based on both of each of the pixel values for compensation and values of adjacent pixels thereof. | 04-21-2016 |
20160163352 | Systems and Methods for Multi-Dimensional Equalization Constraint - 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. | 06-09-2016 |
20160379680 | WRITE ENCROACHMENT MITIGATION SYSTEM - The disclosed technology provides for a method and system comprising determining a write-encroachment threshold of a recording medium, determining a track as off-track and one or more tracks substantially near the off-track as unwriteable, flagging the one or more tracks substantially near the off-track track, and writing write data for the one or more flagged tracks to a media cache. In a recovery process, the write data can be later transferred back to the flagged tracks. | 12-29-2016 |