Patents by Inventor Mehmet Fatih Erden

Mehmet Fatih Erden has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7667912
    Abstract: A method of detecting a cycle slip in a data string read from a bit patterned media and adjusting the data string to compensate for the cycle slip is disclosed. A system including a writeable data storage medium and a compensator configured to adjust data read from the data storage medium to compensate for a cycle slip during the writing of the data onto the storage medium is also disclosed.
    Type: Grant
    Filed: July 3, 2007
    Date of Patent: February 23, 2010
    Assignee: Seagate Technology LLC
    Inventors: Jason Seth Goldberg, Mehmet Fatih Erden
  • Publication number: 20100027605
    Abstract: An equalizer employed in conjunction with bit-patterned media (BPM) is designed to take advantage of a common topology associated with BPM in which each data track is comprised of a plurality of sub-tracks. The equalizer-target filter pair is designed as multiple-input/multiple-output (MIMO) system, in which the readback signal is divided into readback signals associated with each sub-track. The MIMO equalizer takes into account differences in the channel response associated with each sub-track. A detector is configured to receive a plurality of equalized inputs provided by the MIMO equalizer, wherein the detector generates in response estimates of the user data stored on each of the plurality of sub-tracks.
    Type: Application
    Filed: August 4, 2008
    Publication date: February 4, 2010
    Applicant: Seagate Technology LLC
    Inventors: Sundararajan Sankaranarayanan, Mehmet Fatih Erden, Raman Chatapuram Venkataramani
  • Patent number: 7643235
    Abstract: Timing recovery and synchronization for data communication is utilized. A pilot sequence of signals can be selected to improve recovery of a phase offset and a frequency offset in a communication system. Sampling instances can further be adjusted based on pilot sequences within a user data portion.
    Type: Grant
    Filed: September 28, 2006
    Date of Patent: January 5, 2010
    Assignee: Seagate Technology LLC
    Inventors: Mehmet Fatih Erden, Erozan Mehmet Kurtas, Mark Edward Re
  • Patent number: 7602863
    Abstract: A method includes the steps of receiving a signal indicative of data bits, and performing per survivor processing-iterative timing recovery (PSP-ITR) on the received signal to generate probabilities of the data bits. To perform PSP-ITR on the received signal, the signal can be processed using a per survivor processing-soft decision algorithm (PSP-SDA) which jointly performs timing recovery and equalization in accordance with embodiments of the present invention. The soft decision algorithm (SDA) can be, for example, a Bahl, Cocke, Jelinek, and Raviv (BCJR) algorithm or a Soft Output Viterbi Algorithm (SOVA) modified in accordance with the concepts of the present invention such that it is configured to implement per survivor processing (PSP) to jointly perform timing recovery and equalization.
    Type: Grant
    Filed: September 24, 2004
    Date of Patent: October 13, 2009
    Assignee: Seagate Technology LLC
    Inventors: Piya Kovintavewat, John Robert Barry, Mehmet Fatih Erden, Erozan Mehmet Kurtas
  • Publication number: 20090207519
    Abstract: An apparatus comprises a storage medium, a recording head, a source of electromagnetic radiation, and a control circuit for modulating the source of electromagnetic radiation in response to a static deviation of a spacing between the recording head and the storage medium. A method of compensating a static deviation of a spacing between a recording head and a storage medium performed by the apparatus, and a method of precompensating for nonlinear transition shifts in a heat assisted magnetic recording system, are also provided.
    Type: Application
    Filed: March 10, 2009
    Publication date: August 20, 2009
    Applicant: Seagate Technology LLC
    Inventors: Mehmet Fatih Erden, Priyadarshee Deeptarag Mathur, William Albert Challener, Edward Charles Gage, Wei Peng, Terry Wayne McDaniel, Tim Rausch
  • Patent number: 7576942
    Abstract: A method and system determines the position of a transducer head based on permanent servo marks in which the width of the permanent servo marks is greater than the width of the data tracks they are used to identify. The method includes receiving readback signals in response to the permanent servo marks arranged as a number of null bursts and generating position error signals with respect to each null burst. Region based information is extracted based on the position error signals, and the region based information is used in conjunction with the position error signals to generate region-based displacement estimates with respect to each null burst. The region-based estimates are then combined to generate a final displacement estimate that describes the estimated distance between a transducer head and the centerline of a desired data track.
    Type: Grant
    Filed: April 22, 2008
    Date of Patent: August 18, 2009
    Assignee: Seagate Technology LLC
    Inventors: Darren William Karns, Mark David Bedillion, Qiang Ling, Mehmet Fatih Erden
  • Patent number: 7564931
    Abstract: A method of timing recovery comprises receiving an input signal, sampling the input signal to produce a plurality of signal samples, detecting the samples to produce an output signal, and controlling timing of the sampling in response to a maximum-likelihood estimation of timing error between an actual sampling time instant and a desired sampling time instant. Apparatus that performs the method is also provided.
    Type: Grant
    Filed: May 10, 2005
    Date of Patent: July 21, 2009
    Assignee: Seagate Technology LLC
    Inventors: Raman Venkataramani, Mehmet Fatih Erden
  • Patent number: 7564388
    Abstract: A method of reading data is provided. The method includes receiving an analog signal, converting the analog signal to a one bit wide digital signal at a first sampling frequency, and downsampling the digital signal to provide the one bit wide digital signal at a second sampling frequency. The method further includes conditioning the digital signal prior to providing the digital signal to the detector. The conditioning can be performed after downsampling the digital signal. A data communication channel is also provided. The data communication channel includes an analog to digital converter configured to provide a first one bit wide digital data stream at a first sampling frequency and a signal conditioning member configured to accept the first one bit wide digital data stream at a first sampling frequency and provide a second one bit wide digital data stream at a second sampling frequency.
    Type: Grant
    Filed: December 12, 2006
    Date of Patent: July 21, 2009
    Assignee: Seagate Technology LLC
    Inventors: Jongrit Lerdworatawee, Mehmet Fatih Erden
  • Patent number: 7515372
    Abstract: An apparatus comprises a storage medium, a recording head, a source of electromagnetic radiation, and a control circuit for modulating the source of electromagnetic radiation in response to a static deviation of a spacing between the recording head and the storage medium. A method of compensating a static deviation of a spacing between a recording head and a storage medium performed by the apparatus, and a method of precompensating for nonlinear transition shifts in a heat assisted magnetic recording system, are also provided.
    Type: Grant
    Filed: April 3, 2006
    Date of Patent: April 7, 2009
    Assignee: Seagate Technology LLC
    Inventors: Mehmet Fatih Erden, Priyadarshee Deeptarag Mathur, William Albert Challener, Edward Charles Gage, Wei Peng, Terry Wayne McDaniel
  • Publication number: 20090086360
    Abstract: A method of calculating a position error signal is provided. The method includes receiving an analog signal from a data channel and converting the analog signal to a one bit wide digital signal. The analog signal is converted to a digital signal at an oversampled frequency. The position error signal is then calculated by summing correlated oversampled digital signals.
    Type: Application
    Filed: October 2, 2007
    Publication date: April 2, 2009
    Applicant: Seagate Technology LLC
    Inventors: Qiang Ling, Mehmet Fatih Erden
  • Publication number: 20090086846
    Abstract: A communication system includes a physical communication channel. A signal is transmitted across the communication channel from a transmit end of the channel to a receive end of the channel. A plurality of processing branches process the signal at the receive end of the communication channel. This reduces complexity of the receive channel, without reducing a bandwidth of the given communication channel, and without comprising performance.
    Type: Application
    Filed: October 2, 2007
    Publication date: April 2, 2009
    Applicant: Seagate Technology LLC
    Inventor: Mehmet Fatih Erden
  • Publication number: 20090086356
    Abstract: 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.
    Type: Application
    Filed: October 2, 2007
    Publication date: April 2, 2009
    Applicant: Seagate Technology LLC
    Inventors: Alexander Vasilievich Kuznetsov, Mehmet Fatih Erden
  • Publication number: 20090067090
    Abstract: A patterned recording media comprises a segment and a null pattern formed in the segment. The segment comprises first and second rows of discrete magnetic elements separated by a non-magnetic material, and a row of non-magnetic material positioned between the first and second rows. The null pattern comprises consecutive groups of the discrete magnetic elements in the first and second rows of the segment. Each group in the first row has a magnetic polarity that is opposite the magnetic polarity of adjoining groups in the first row. Each group in the second row has a magnetic polarity that is opposite the magnetic polarity of adjoining groups in the second row.
    Type: Application
    Filed: September 12, 2007
    Publication date: March 12, 2009
    Applicant: Seagate Technology LLC
    Inventors: Qiang Ling, Mehmet Fatih Erden, Alexei H. Sacks, Sundeep Chauhan
  • Publication number: 20090059412
    Abstract: A method is disclosed for determining position information of a transducer. At least a first code and a second code are chosen. The first code has different characteristics than the second code. User data written to a first sub-track is encoded with the first code and user data written to a second sub-track is encoded with the second code. The first code read from the first sub-track is obtained and the second code read from the second sub-track is obtained. Position information of the transducer is extracted from the obtained characteristics of the first code and the obtained characteristics of the second code.
    Type: Application
    Filed: September 5, 2007
    Publication date: March 5, 2009
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Mehmet Fatih Erden, Rene Johannes Marinus van de Veerdonk, Alexei Hiram Sacks
  • Publication number: 20090009901
    Abstract: A method of detecting a cycle slip in a data string read from a bit patterned media and adjusting the data string to compensate for the cycle slip is disclosed. A system including a writeable data storage medium and a compensator configured to adjust data read from the data storage medium to compensate for a cycle slip during the writing of the data onto the storage medium is also disclosed.
    Type: Application
    Filed: July 3, 2007
    Publication date: January 8, 2009
    Applicant: Seagate Technology LLC
    Inventors: Jason Seth Goldberg, Mehmet Fatih Erden
  • Publication number: 20090002865
    Abstract: A method includes: producing a bit detection signal in response to a plurality of islands located in a plurality of zones of a bit patterned media, processing the bit detection signal to produce a synchronization signal, wherein the processing is dependent on characteristics of the islands in the zone containing the plurality of islands, and using the synchronization signal to control timing of writing to the bit patterned media. The synchronization signal can also be used to control timing of reading from the bit patterned media.
    Type: Application
    Filed: June 28, 2007
    Publication date: January 1, 2009
    Applicant: Seagate Technology LLC
    Inventors: Raman Chatapuram Venkataramani, Sundararajan Sankaranarayanan, Mehmet Fatih Erden
  • Publication number: 20080151405
    Abstract: A storage device has a storage medium, a plurality of read-write mechanisms, a quality monitoring and book-keeping unit and a scheduling unit. The plurality of read-write mechanisms is coupled to the storage medium. The quality monitoring and book-keeping unit is coupled to the plurality of read-write mechanisms and is adapted to monitor at least one performance parameter associated with each read-write mechanism during operation. The scheduling unit is coupled to the quality monitoring and book-keeping unit. The scheduling unit is adapted to rank each of the plurality of read-write mechanisms according to the at least one performance parameter and to responsively schedule use of a read-write mechanism according to its rank.
    Type: Application
    Filed: January 29, 2008
    Publication date: June 26, 2008
    Applicant: Seagate Technology LLC
    Inventors: Erozan Mehmet Kurtas, Mehmet Fatih Erden, Xueshi Yang
  • Publication number: 20080144452
    Abstract: A method is provided, which includes reading data from a data storage medium. Reading data from the medium causes the data to be erased. The method further includes determining a desired position to rewrite the data by computing a position error signal based on the data signal and compensating the position error signal for non-zero bias. The data is then rewritten non-synchronously. An apparatus is also provided, including a data storage medium with a data communication transducer configured to receive data from the medium. Data is erased after it is read. The data communication transducer is configured to rewrite the read data back onto the data storage medium in a non-synchronously. A non-zero bias compensator is provided to compensate data received by the data communication transducer to determine a desired position to rewrite the previously read data back onto the medium.
    Type: Application
    Filed: December 15, 2006
    Publication date: June 19, 2008
    Applicant: Seagate Technology LLC
    Inventors: Qiang Ling, Mehmet Fatih Erden
  • Publication number: 20080136692
    Abstract: A method of reading data is provided. The method includes receiving an analog signal, converting the analog signal to a one bit wide digital signal at a first sampling frequency, and downsampling the digital signal to provide the one bit wide digital signal at a second sampling frequency. The method further includes conditioning the digital signal prior to providing the digital signal to the detector. The conditioning can be performed after downsampling the digital signal. A data communication channel is also provided. The data communication channel includes an analog to digital converter configured to provide a first one bit wide digital data stream at a first sampling frequency and a signal conditioning member configured to accept the first one bit wide digital data stream at a first sampling frequency and provide a second one bit wide digital data stream at a second sampling frequency.
    Type: Application
    Filed: December 12, 2006
    Publication date: June 12, 2008
    Applicant: Seagate Technology LLC
    Inventors: Jongrit Lerdworatawee, Mehmet Fatih Erden
  • Publication number: 20080080082
    Abstract: Timing recovery and synchronization for data communication is utilized. A pilot sequence of signals can be selected to improve recovery of a phase offset and a frequency offset in a communication system. Sampling instances can further be adjusted based on pilot sequences within a user data portion.
    Type: Application
    Filed: September 28, 2006
    Publication date: April 3, 2008
    Applicant: Seagate Technology LLC
    Inventors: Mehmet Fatih Erden, Erozan Mehmet Kurtas, Mark Edward Re