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76 条记录 (耗时 0.026 秒)

    Gain and phase constrained adaptive equalizing filter in a sampled amplitude read channel for magnetic recording
    3.
    发明授权
    Gain and phase constrained adaptive equalizing filter in a sampled amplitude read channel for magnetic recording 有权
    用于磁记录的采样振幅读通道中的增益和相位约束自适应均衡滤波器

    公开(公告)号：US06208481B1

    公开(公告)日：2001-03-27

    申请号：US09342167

    申请日：1999-06-28

    申请人： Mark S. Spurbeck ,  Li Du ,  Trent O. Dudley ,  William G. Bliss ,  German S. Feyh ,  Richard T. Behrens

    发明人： Mark S. Spurbeck ,  Li Du ,  Trent O. Dudley ,  William G. Bliss ,  German S. Feyh ,  Richard T. Behrens

    IPC分类号： G11B5035

    CPC分类号： G11B20/10055 ,  G11B5/012 ,  G11B5/035 ,  G11B5/09 ,  G11B20/10009 ,  G11B20/10037 ,  G11B20/1403 ,  H04L7/0029 ,  H04L7/0062

    摘要： A sampled amplitude read channel for magnetic disk recording which asynchronously samples the analog read signal, adaptively equalizes the resulting discrete time sample values according to a target partial response, extracts synchronous sample values through interpolated timing recovery, and detects digital data from the synchronous sample values using a Viterbi sequence detector is disclosed. To minimize interference from the timing and gain control loops, the phase and magnitude response of the adaptive equalizer filter are constrained at a predetermined frequency using an optimal orthogonal projection operation as a modification to a least mean square (LMS) adaptation algorithm. Further, with interpolated timing recovery, the equalizer filter and its associated latency are removed from the timing recovery loop, thereby allowing a higher order discrete time filter and a lower order analog filter.

    摘要翻译： 用于磁盘记录的采样幅度读取通道，其异步采样模拟读取信号，根据目标部分响应对所得离散时间采样值进行自适应均衡，通过内插定时恢复提取同步采样值，并从同步采样值检测数字数据 公开了使用维特比序列检测器。 为了最小化来自定时和增益控制环路的干扰，使用最佳正交投影操作将自适应均衡器滤波器的相位和幅度响应约束在预定频率，作为对最小均方（LMS）适配算法的修改。 此外，通过内插定时恢复，均衡器滤波器及其相关等待时间从定时恢复环路中移除，从而允许较高阶离散时间滤波器和较低阶模拟滤波器。

    Method and apparatus for calibrating an analog filter in a sampled amplitude read channel
    9.
    发明授权
    Method and apparatus for calibrating an analog filter in a sampled amplitude read channel 失效
    用于校准采样振幅读通道中的模拟滤波器的方法和装置

    公开(公告)号：US5903857A

    公开(公告)日：1999-05-11

    申请号：US751832

    申请日：1996-11-18

    申请人： Richard T. Behrens ,  Tyson Tuttle ,  Kent D. Anderson ,  Trent O. Dudley ,  William G. Bliss

    发明人： Richard T. Behrens ,  Tyson Tuttle ,  Kent D. Anderson ,  Trent O. Dudley ,  William G. Bliss

    IPC分类号： G11B20/10 ,  G06F17/10 ,  G11B5/035

    CPC分类号： G11B20/10055 ,  G11B20/10009 ,  G11B20/10037 ,  G11B20/10481

    摘要： A method and apparatus for calibrating an analog equalizer in a sampled amplitude read channel is disclosed wherein the filter's frequency response is measured and calibrated directly. This is accomplished by injecting a known periodic signal into the analog filter and measuring a spectrum value at a predetermined frequency. The filter parameters are adjusted accordingly until the spectrum reaches a predetermined target value. In the preferred embodiment, the analog filter comprises at least one second order low pass filter (referred to as a biquad filter), and the filter's spectrum is adjusted relative to the well known parameters f.sub.o and Q. Specifically, the parameters f.sub.o and Q are optimized relative to a power measurement at predetermined harmonics of the input signal. In this manner, the present invention enables auto-calibration of the analog equalizer without reading any data from the disc. Furthermore, the calibration process can be executed during the storage system's normal operation without significantly degrading its overall performance.

    摘要翻译： 公开了一种用于校准采样振幅读通道中的模拟均衡器的方法和装置，其中滤波器的频率响应被直接测量和校准。 这是通过将已知的周期信号注入模拟滤波器并以预定频率测量频谱值来实现的。 相应地调整滤波器参数，直到频谱达到预定的目标值。 在优选实施例中，模拟滤波器包括至少一个二阶低通滤波器（称为双二阶滤波器），并且相对于众所周知的参数fo和Q调节滤波器的频谱。具体地，参数fo和Q是 相对于输入信号的预定谐波处的功率测量而优化。 以这种方式，本发明能够在不从盘读取任何数据的情况下自动校准模拟均衡器。 此外，可以在存储系统的正常操作期间执行校准过程，而不会显着降低其整体性能。

    Fault tolerant sync mark detector enabled relative to a frequency of an acquisition preamble for sampled amplitude recording
    10.
    发明授权
    Fault tolerant sync mark detector enabled relative to a frequency of an acquisition preamble for sampled amplitude recording 失效
    容错同步标记检测器相对于采样幅度记录的采集前导码的频率启用

    公开(公告)号：US5729396A

    公开(公告)日：1998-03-17

    申请号：US440268

    申请日：1995-05-12

    申请人： Trent O. Dudley ,  Richard T. Behrens ,  Christopher P. Zook

    发明人： Trent O. Dudley ,  Richard T. Behrens ,  Christopher P. Zook

    IPC分类号： G11B5/012 ,  G11B20/10 ,  G11B20/14 ,  G11B27/30 ,  G11B5/09

    CPC分类号： G11B20/10055 ,  G11B20/10009 ,  G11B20/10037 ,  G11B20/1403 ,  G11B27/30 ,  G11B27/3027 ,  G11B5/012 ,  G11B2020/1476

    摘要： A sampled amplitude read channel reads data from a magnetic medium by detecting digital data from a sequence of discrete time sample values generated by sampling an analog read signal from a read head positioned over the magnetic medium. The digital data comprises a preamble field followed by a sync mark followed by a data field. Timing recovery in the read channel synchronizes to a phase and frequency of the preamble field and a sync detector detects the sync mark in order to frame operation of an RLL decoder for decoding the detected data field. To decrease the probability of early misdetection, the sync mark is chosen to have minimum correlation with shifted versions of the sync mark concatenated with the preamble field. To further increase the fault tolerance, the sync mark detector is enabled by timing recovery relative to the end of the preamble field. A state machine in timing recovery generates expected sample values used to acquire the preamble field, and a current state of the state machine indicates when the preamble ends relative to a predetermined clock interval. In this manner, the search for an appropriate sync mark need only look for minimum correlation during shifts at the predetermined clock interval, thereby increasing the fault tolerant characteristic of the sync mark.

    摘要翻译： 采样幅度读取通道从通过从位于磁性介质上的读取头采样模拟读取信号而产生的离散时间采样值的序列中检测数字数据，从磁性介质读取数据。 数字数据包括前同步码字段，随后是同步标记，后跟数据字段。 读通道中的定时恢复与前同步码字段的相位和频率同步，并且同步检测器检测同步标记，以便对RLL解码器进行帧操作，以对检测到的数据字段进行解码。 为了降低早期错误检测的可能性，选择同步标记与与前同步码字段连接的同步标记的移位版本具有最小相关性。 为了进一步增加容错能力，同步标记检测器通过相对于前同步码字段结束的定时恢复来启用。 定时恢复中的状态机产生用于获取前导字段的预期采样值，并且状态机的当前状态指示前导码相对于预定时钟间隔何时结束。 以这种方式，搜索适当的同步标记仅需要在预定时钟间隔期间寻找在移位期间的最小相关性，从而增加同步标记的容错特性。