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Patent Issued for Data Detector for Detecting Data in Presence of Control Signals

September 9, 2014



By a News Reporter-Staff News Editor at Information Technology Newsweekly -- From Alexandria, Virginia, VerticalNews journalists report that a patent by the inventors Wu, Zining (Los Altos, CA); Sutardja, Pantas (Los Gatos, CA), filed on September 21, 2012, was published online on August 26, 2014.

The patent's assignee for patent number 8817414 is Marvell International Ltd. (BM).

News editors obtained the following quote from the background information supplied by the inventors: "The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventor(s), to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

"Many data storage devices use detectors to reproduce data from a read signal when reading a storage medium. The detector reproduces the data by, for example, detecting the data in the read signal and converting the data from an analog signal into a binary format. However, detecting the data can be complicated by the presence of noise in the read signal. For example, the read signal can include the stored data and embedded control signals. Control signals are sometimes stored with the data to provide information about data locations in a storage medium. A data storage device uses the location information during read and write operations to ensure data is being read from a correct location in the storage medium.

"However, when the control signal is present in the read signal, difficulties with decoding the data occur. Decoding difficulties occur because of interference from the control signal with detection of data and an increased signal-to-noise ratio (SNR) requirement of the detector. Thus, a higher bit error rate (BER) is present from the interference, which leads to the difficulties in decoding the read signal."

As a supplement to the background information on this patent, VerticalNews correspondents also obtained the inventors' summary information for this patent: "In one embodiment, a detector for detecting a data signal embedded in a read signal from a storage device includes a signal estimator configured to generate an estimate of the control signal from the read signal by sampling the read signal to determine characteristics of the control signal. The read signal includes the data signal and the control signal. The signal estimator uses the characteristics to calculate the estimate of the control signal. The detector also includes a cancellation unit configured to produce the data signal by cancelling the estimate of the control signal from the read signal.

"In another embodiment, the control signal is a continuous servo signal that is embedded with the data signal. The continuous servo signal guides the storage device when reading data from a storage medium of the storage device.

"In another embodiment, the characteristics of the control signal include a phase and an amplitude. The cancellation unit is configured to cancel the estimate of the control signal from the read signal by combining an inverse of the estimate of the control signal with the read signal.

"In another embodiment, the signal estimator is configured to remove the data signal from the read signal by using a filter and to use a remainder of the read signal to generate the estimate of the control signal.

"In another embodiment, the read signal is a sinusoidal waveform. The signal estimator includes a filter that isolates a frequency band of the control signal to remove noise from the data signal of the read signal when generating the estimate of the control signal.

"In one embodiment, a method for detecting a data signal embedded in a read signal of a storage device includes generating, in a hardware detector configured to perform the method, an estimate of a control signal from the read signal by sampling the read signal to determine characteristics of the control signal. The read signal includes the data signal and the control signal. Generating the estimate includes calculating the estimate using the characteristics. The method also includes producing the data signal by cancelling the estimate of the control signal from the read signal.

"In another embodiment, the control signal is a continuous servo signal that is embedded with the data signal. The continuous servo signal guides the storage device when reading data from a storage medium of the storage device.

"In another embodiment, the characteristics of the control signal include a phase and an amplitude. Cancelling the estimate of the control signal from the read signal includes subtracting the estimate of the control signal from the read signal.

"In another embodiment, the method also includes filtering the read signal to isolate a frequency band of the control signal from the read signal. Filtering the read signal removes portions of the data signal from the read signal that have a different frequency than the control signal.

"In another embodiment, generating the estimate of the control signal includes using a filter to remove portions of the data signal from the read signal and using a remainder of the read signal to generate the estimate of the control signal.

"In one embodiment, a data detector for detecting a data signal embedded in a read signal that is produced by a storage device includes a signal estimator configured to determine characteristics of a servo signal from the read signal and to generate an estimate of the servo signal using the characteristics. The read signal includes the data signal and the servo signal. The data detector also includes a cancellation unit configured to output the data signal by applying the estimate of the servo signal to the read signal to cancel the servo signal from the read signal."

For additional information on this patent, see: Wu, Zining; Sutardja, Pantas. Data Detector for Detecting Data in Presence of Control Signals. U.S. Patent Number 8817414, filed September 21, 2012, and published online on August 26, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8817414.PN.&OS=PN/8817414RS=PN/8817414

Keywords for this news article include: Information Technology, Information and Data Storage, Marvell International Ltd.

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Source: Information Technology Newsweekly


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