公开(公告)号：US08015477B2

公开(公告)日：2011-09-06

申请号：US12819993

申请日：2010-06-21

申请人： Heinrich J. Stockmanns ,  William G. Bliss ,  Razmik Karabed ,  James W. Rae

发明人： Heinrich J. Stockmanns ,  William G. Bliss ,  Razmik Karabed ,  James W. Rae

IPC分类号： H03M13/03

CPC分类号： G11B20/10296 ,  G11B20/10009

摘要： An improved Viterbi detector is disclosed in which each branch metric is calculated based on noise statistics that depend on the signal hypothesis corresponding to the branch. Also disclosed is a method of reducing the complexity of the branch metric calculations by clustering branches corresponding to signals with similar signal-dependent noise statistics. A feature of this architecture is that the branch metrics (and their corresponding square difference operators) are clustered into multiple groups, where all the members of each group draw input from a single, shared noise predictive filter corresponding to the group. In recording technologies as practiced today, physical imperfections in the representation of recorded user data in the recording medium itself are becoming the dominate source of noise in the read back data. This noise is highly dependent on what was (intended to be) written in the medium. The disclosed Viterbi detector exploits this statistical dependence of the noise on the signal.

摘要翻译： 公开了一种改进的维特比检测器，其中基于依赖于与分支对应的信号假设的噪声统计来计算每个分支度量。 还公开了一种通过对与具有相似的信号相关噪声统计信号的信号进行聚类的分支来降低分支度量计算的复杂度的方法。 该架构的一个特点是分支度量（及其对应的平方差运算符）被聚集成多个组，其中每个组的所有成员从与组相对应的单个共享噪声预测滤波器中绘制输入。 在今天所采用的记录技术中，在记录介质本身中记录的用户数据的表示中的物理缺陷正在回读数据中成为主要的噪声源。 这种噪音很大程度上取决于介质中写的内容。 所公开的维特比检测器利用噪声对信号的统计依赖性。

公开(公告)号：US20100322359A1

公开(公告)日：2010-12-23

申请号：US12819993

申请日：2010-06-21

申请人： Heinrich J. Stockmanns ,  William G. Bliss ,  Razmik Karabed ,  James W. Rae

发明人： Heinrich J. Stockmanns ,  William G. Bliss ,  Razmik Karabed ,  James W. Rae

IPC分类号： H04L27/06

CPC分类号： G11B20/10296 ,  G11B20/10009

摘要： An improved Viterbi detector is disclosed in which each branch metric is calculated based on noise statistics that depend on the signal hypothesis corresponding to the branch. Also disclosed is a method of reducing the complexity of the branch metric calculations by clustering branches corresponding to signals with similar signal-dependent noise statistics. A feature of this architecture is that the branch metrics (and their corresponding square difference operators) are clustered into multiple groups, where all the members of each group draw input from a single, shared noise predictive filter corresponding to the group. In recording technologies as practiced today, physical imperfections in the representation of recorded user data in the recording medium itself are becoming the dominate source of noise in the read back data. This noise is highly dependent on what was (intended to be) written in the medium. The disclosed Viterbi detector exploits this statistical dependence of the noise on the signal.

摘要翻译： 公开了一种改进的维特比检测器，其中基于依赖于与分支对应的信号假设的噪声统计来计算每个分支度量。 还公开了一种通过对与具有相似的信号相关噪声统计信号的信号进行聚类的分支来降低分支度量计算的复杂度的方法。 该架构的一个特点是分支度量（及其对应的平方差运算符）被聚集成多个组，其中每个组的所有成员从与组相对应的单个共享噪声预测滤波器中绘制输入。 在今天所采用的记录技术中，在记录介质本身中记录的用户数据的表示中的物理缺陷正在回读数据中成为主要的噪声源。 这种噪音很大程度上取决于介质中写的内容。 所公开的维特比检测器利用噪声对信号的统计依赖性。

公开(公告)号：US20090168620A1

公开(公告)日：2009-07-02

申请号：US12345561

申请日：2008-12-29

申请人： William G. Bliss ,  Razmik Karabed

发明人： William G. Bliss ,  Razmik Karabed

IPC分类号： G11B19/02 ,  G11B5/02

CPC分类号： G11B20/10194 ,  G11B20/10009 ,  G11B20/1426 ,  G11B20/1833 ,  G11B2220/2516

摘要： The invention relates to a data modulation method applicable to make data streams tend to have desired properties, useful for clock recovery, making signals more distinguishable, or enforcing run-length conditions. A stream of input data and a corresponding stream of output data are grouped into elements of a finite field. Input elements of said input data are modified by a transform generating output elements of the output data, such that a current output element is a linear combination of a current input element and at least one previous output element. A multiplier applied to at least one previous output element is a non-zero and non-unity element of the finite field. A set of initial conditions inherent to the transform, is selected such that the output elements resulting from the transform tend to have the desired property.

摘要翻译： 本发明涉及一种适用于使数据流倾向于具有期望属性的数据调制方法，对于时钟恢复有用，使得信号更可区分，或者执行运行长度条件。 输入数据流和相应的输出数据流被分组成有限域的元素。 通过产生输出数据的输出元件的变换来修改所述输入数据的输入元件，使得当前输出元件是当前输入元件和至少一个先前输出元件的线性组合。 应用于至少一个先前输出元素的乘数是有限域的非零和非单位元素。 选择变换固有的一组初始条件，使得由变换产生的输出元素倾向于具有期望的属性。

公开(公告)号：US06216249B1

公开(公告)日：2001-04-10

申请号：US09261417

申请日：1999-03-03

申请人： William G. Bliss ,  Sian She

发明人： William G. Bliss ,  Sian She

IPC分类号： G06F1110

CPC分类号： G11B20/10055 ,  G11B20/10009 ,  G11B20/10037 ,  G11B20/1426 ,  H03M13/3961 ,  H03M13/4107 ,  H03M13/6343 ,  H03M13/6502

摘要： A sampled amplitude read channel for use in disk storage systems (magnetic or optical) is disclosed comprising a simplified branch metric calculator for use in a trellis sequence detector. Instead of computing the traditional Euclidean branch metric as the squared difference between the actual signal sample and the expected signal sample of the target partial response, the present invention computes a simplified branch metric which is then saturated in order to reduce the number of bits required to calculate and store the branch metrics, thereby simplifying the branch metric calculators as well as reducing the add-compare-select (ACS) circuitry for each state in the trellis. Furthermore, the saturation technique of the present invention is substantially data independent meaning that the saturation threshold is essentially independent from the signal samples used to compute the branch metric.

摘要翻译： 公开了一种用于磁盘存储系统（磁或光）的采样幅度读通道，其包括用于网格序列检测器的简化分支度量计算器。 传统的欧几里德分支量度作为实际信号采样与目标部分响应的预期信号采样之间的平方差，而不是计算一个简化的分支量度，然后饱和，以减少所需的位数 计算和存储分支度量，从而简化分支度量计算器以及减少网格中每个状态的加法比较选择（ACS）电路。 此外，本发明的饱和技术基本上是数据无关的，这意味着饱和阈值基本上与用于计算分支度量的信号样本无关。

公开(公告)号：US06185173B2

公开(公告)日：2001-02-06

申请号：US09127101

申请日：1998-07-31

申请人： Jay N. Livingston ,  William G. Bliss

发明人： Jay N. Livingston ,  William G. Bliss

IPC分类号： G11B700

CPC分类号： G11B20/10055 ,  G11B20/10037 ,  G11B20/1426 ,  H03M13/00

摘要： A sampled amplitude read channel is disclosed for disk storage systems comprising a encoder/decoder for implementing a high rate channel code that codes out specific minimum distance error events of a trellis sequence detector by enforcing a particular code constraint. The trellis sequence detector comprises a state machine matched to the code constraint which effectively removes the corresponding minimum distance errors from the detected output sequence. Additionally, the channel code encodes redundancy bits into the write data for implementing an error detection code. The redundancy bits are processed during a read operation to generate an error syndrome used to detect and correct other dominant error events, such as the NRZ (+) and (+−+) error events. In this manner, the most likely error events of the trellis sequence detector are either coded out by the channel code constraint, or detected and corrected using the error syndrome. As a result, the present invention provides a significant distance enhancing performance gain over the prior art without decreasing the system's code rate, thereby providing a substantial increase in linear bit density and overall storage capacity.

摘要翻译： 公开了一种用于磁盘存储系统的采样幅度读取通道，其包括用于实现高速率信道码的编码器/解码器，该高速率信道码通过执行特定的码约束来编码网格序列检测器的特定最小距离误差事件。 网格序列检测器包括与代码约束匹配的状态机，其有效地从检测到的输出序列中去除对应的最小距离误差。 另外，通道代码将冗余位编码到写入数据中，以实现错误检测码。 在读取操作期间处理冗余位以产生用于检测和校正其他主要错误事件（例如NRZ（+）和（+ - +））错误事件的错误校正。 以这种方式，网格序列检测器的最可能的错误事件或者通过信道码约束进行编码，或使用误差综合征检测和校正。 结果，本发明提供了超过现有技术的显着的距离增强性能增益，而不降低系统的码率，从而提供线性位密度和总体存储容量的显着增加。

公开(公告)号：US6157604A

公开(公告)日：2000-12-05

申请号：US80559

申请日：1998-05-18

申请人： German S. Feyh ,  Jim Graba ,  William G. Bliss

发明人： German S. Feyh ,  Jim Graba ,  William G. Bliss

IPC分类号： G11B20/14 ,  G11B27/30 ,  H03L7/091 ,  H03M13/41 ,  H04N5/85 ,  H04N5/76

CPC分类号： G11B20/10037 ,  G11B20/10055 ,  G11B20/10296 ,  G11B20/1403 ,  G11B27/3027 ,  H03L7/091 ,  H03M13/41 ,  H03M13/6331 ,  H03M13/6505 ,  H03M13/6563 ,  H03M13/6569 ,  H04N5/85 ,  G11B2020/10916 ,  G11B2220/2545 ,  G11B2220/2562

摘要： A sampled amplitude read channel for optical disk storage systems is disclosed comprising an all digital timing recovery circuit. The RF read signal from the read head is sampled asynchronous to the baud rate and the asynchronous sample values are interpolated to generate sample values that are substantially synchronous to the baud rate. A data detector, such as a Viterbi sequence detector, processes the synchronous sample values to generate an estimated binary sequence representing the recorded binary sequence. The timing recovery circuit comprises a baud rate estimator for estimating the baud rate relative to the sampling rate, wherein the estimated baud rate is used to initialize a timing recovery loop filter at the end of seek operations. The all digital timing recovery circuit and baud rate estimator enable the storage device to begin reading the user data immediately after a seek operation, rather than wait for the CLV servo loop to acquire the target spindle speed.

摘要翻译： 公开了一种用于光盘存储系统的采样幅度读取通道，其包括全数字定时恢复电路。 来自读取头的RF读取信号与波特率异步采样，并且内插异步采样值以产生与波特率基本同步的采样值。 诸如维特比序列检测器的数据检测器处理同步采样值以产生表示记录的二进制序列的估计二进制序列。 定时恢复电路包括用于估计相对于采样率的波特率的波特率估计器，其中所估计的波特率用于在搜索操作结束时初始化定时恢复环路滤波器。 全数字定时恢复电路和波特率估计器使存储设备能够在搜索操作之后立即开始读取用户数据，而不是等待CLV伺服循环获取目标主轴转速。

公开(公告)号：US5966258A

公开(公告)日：1999-10-12

申请号：US859980

申请日：1997-05-21

申请人： William G. Bliss

发明人： William G. Bliss

IPC分类号： G11B5/012 ,  G11B5/09 ,  G11B5/55 ,  G11B5/58 ,  G11B5/596 ,  G11B19/28 ,  G11B20/10 ,  G11B20/12 ,  G11B20/14

CPC分类号： G11B20/10055 ,  G11B19/28 ,  G11B20/10009 ,  G11B20/10037 ,  G11B20/1403 ,  G11B5/012 ,  G11B5/09 ,  G11B5/5526 ,  G11B5/553 ,  G11B5/5547 ,  G11B5/58 ,  G11B5/59605 ,  G11B5/59622 ,  G11B5/59633 ,  G11B5/59688 ,  G11B20/1258 ,  G11B5/5534 ,  G11B5/5965

摘要： A sampled amplitude read channel is disclosed for reading data recorded on a disk storage medium by detecting an estimated binary sequence from a sequence of discrete-time sample values generated by sampling pulses in an analog read signal from a read head positioned over the disk storage medium. The read channel comprises a variable gain amplifier for adjusting the magnitude of the analog read signal before sampling, and a discrete-time gain control loop for generating a gain control signal applied to the VGA in response to the discrete-time sample values. The discrete-time sample values may, or may not be, synchronized to a baud rate of the recorded data. For example, when reading the user data the discrete-time sample values are synchronous, and when reading a servo address mark (SAM) the sample values are asynchronous. As such, the discrete-time gain control loop of the present invention is programmable to operate in a synchronous or asynchronous mode. In asynchronous mode, the gain error is computed in a manner that is less sensitive to amplitude fluctuations over long blocks of data. This is accomplished by computing the gain error as the difference between a predetermined set point and the maximum absolute sample value over a programmable block length.

摘要翻译： 公开了一种采样幅度读取通道，用于通过从位于盘存储介质上的读取头的模拟读取信号中的采样脉冲的一系列离散时间采样值中检测估计的二进制序列来读取记录在盘存储介质上的数据 。 读通道包括用于调整采样之前的模拟读取信号的幅度的可变增益放大器和用于响应于离散时间采样值产生施加到VGA的增益控制信号的离散时间增益控制环路。 离散时间采样值可以或可以不与记录数据的波特率同步。 例如，当读取用户数据时，离散时间采样值是同步的，并且当读取伺服地址标记（SAM）时，采样值是异步的。 因此，本发明的离散时间增益控制环路可编程为以同步或异步模式操作。 在异步模式下，增益误差的计算方式对长数据块的幅度波动较不敏感。 这是通过将增益误差计算为在可编程块长度上的预定设定点和最大绝对样本值之间的差来实现的。

公开(公告)号：US5961658A

公开(公告)日：1999-10-05

申请号：US862492

申请日：1997-05-23

申请人： David E. Reed ,  William G. Bliss ,  Lisa C. Sundell

发明人： David E. Reed ,  William G. Bliss ,  Lisa C. Sundell

IPC分类号： G11B20/18 ,  H03M13/00 ,  H03M13/12

CPC分类号： H03M13/6343 ,  G11B20/10277 ,  H03M13/098 ,  H03M13/3776 ,  H03M13/41 ,  H03M5/145 ,  G11B20/10064 ,  G11B20/10074 ,  G11B20/10175 ,  G11B2020/1446 ,  G11B2220/2516

摘要： A sampled amplitude read channel is disclosed for disk storage systems that employs an EPR4 remod/demod sequence detector. To reduce the complexity of timing recovery, gain control and adaptive equalization, the channel samples are initially equalized into a PR4 partial response so that a simple slicer circuit can generate estimated sample values. The PR4 equalized channel samples are then passed through a 1+D filter to generate EPR4 equalized channel samples which are processed by an EPR4 Viterbi sequence detector to generate a preliminary binary sequence. The preliminary binary sequence is remodulated into an estimated or ideal PR4 sample sequence which is subtracted from the PR4 equalized channel samples to generate an error sample sequence. An error pattern detector processes the error sample sequence to detect the dominant error events associated with the EPR4 Viterbi sequence detector.

摘要翻译： 公开了采用EPR4重构/解调序列检测器的磁盘存储系统的采样幅度读取通道。 为了降低定时恢复的复杂度，增益控制和自适应均衡，信道样本最初被均衡为PR4部分响应，使得简单的限幅电路可以产生估计的采样值。 然后将PR4均衡信道样本通过1 + D滤波器以产生由EPR4维特比序列检测器处理以产生初步二进制序列的EPR4均衡信道样本。 将初步二进制序列重新调制成从PR4均衡信道样本中减去的估计或理想PR4采样序列，以生成误差采样序列。 误差模式检测器处理误差采样序列以检测与EPR4维特比序列检测器相关的主要误差事件。

公开(公告)号：US5926490A

公开(公告)日：1999-07-20

申请号：US862493

申请日：1997-05-23

申请人： David E. Reed ,  William G. Bliss ,  Lisa C. Sundell

发明人： David E. Reed ,  William G. Bliss ,  Lisa C. Sundell

IPC分类号： G11B20/10 ,  G06F11/00

CPC分类号： G11B20/1403 ,  G11B20/10009 ,  G11B20/10037 ,  G11B20/10055

摘要： A sampled amplitude read channel is disclosed for disk storage systems that employs a remod/demod sequence detector guided by an error syndrome of an error detection code (EDC). The remod/demod sequence detector comprises: a conventional trellis type maximum likelihood sequence detector, such as a Viterbi detector, for detecting a preliminary binary sequence from the channel sample values; a syndrome generator for generating an error syndrome in response to the preliminary binary sequence; a remodulator for remodulating the detected binary sequence into a sequence of estimated ideal sample values; a sample error generator for subtracting the channel samples from the estimated samples to generate a sample error sequence; an error pattern detector for detecting potential error events in the sample error sequence; and an error corrector for correcting the preliminary binary sequence when the error syndrome indicates that an error occurred. In the embodiment disclosed herein, the error syndrome is generated as the parity over a predetermined number of bits. When a parity error occurs, a correction is made corresponding to the most likely error event detected. Guiding the remod/demod sequence detector with an error syndrome avoids miscorrections that may otherwise occur in conventional remod/demod sequence detectors.

摘要翻译： 公开了采用由错误检测码（EDC）的误差综合征引导的重构/解调序列检测器的磁盘存储系统的采样幅度读取通道。 重构/解调序列检测器包括：常规网格型最大似然序列检测器，例如维特比检测器，用于从信道样本值检测初步二进制序列; 一种用于响应于初步二进制序列产生误差综合征的综合征发生器; 用于将所检测的二进制序列重新调制成估计的理想样本值的序列的再调制器; 用于从估计样本中减去信道样本以产生样本误差序列的采样误差发生器; 用于检测样本误差序列中的潜在误差事件的误差模式检测器; 以及错误校正器，用于当错误校正器指示发生错误时校正初步二进制序列。 在本文公开的实施例中，错误校正器被生成为超过预定位数的奇偶校验。 当发生奇偶校验错误时，对应于检测到的最可能的错误事件进行校正。 引导具有错误综合征的重构/解调序列检测器避免了传统的重构/解调序列检测器可能发生的误差。

公开(公告)号：US5854714A

公开(公告)日：1998-12-29

申请号：US741156

申请日：1996-10-29

申请人： David E. Reed ,  William G. Bliss

发明人： David E. Reed ,  William G. Bliss

IPC分类号： G11B5/596 ,  G11B21/08 ,  G11B21/10 ,  G11B5/09

CPC分类号： G11B21/083 ,  G11B21/085 ,  G11B21/106 ,  G11B5/59655 ,  G11B5/59688 ,  G11B20/10037 ,  G11B20/10055

摘要： A discrete time servo demodulation technique incorporated within a sampled amplitude read channel to demodulate embedded servo field information stored on a magnetic medium. The servo field information is transduced by a read head into an analog signal, and converted to a sequence of sample values in the read channel. The demodulation technique is responsive to the sample values and includes a discrete time peak detector for detecting servo data, and a discrete time servo burst amplitude detector for measuring the amplitude of servo bursts. Peaks are detected in the analog read signal by sensing a change of slope from the sequence of sample values. The peaks are qualified by polarity in that a peak is detected only if its polarity is opposite in sign from the previous peak. The servo burst amplitudes are measured by interpolating, rectifying, and accumulating the sequence of sample values corresponding to the servo bursts. A plurality of registers store the amplitude measurement of corresponding servo bursts such as the four servo bursts in a quadrature system. The sample values are interpolated, squared, and the sampling frequency dithered in order to decrease the sensitivity of the burst amplitude measurement to variations in the sampling phase and to increase the effective resolution of the read channel ADC for servo demodulation. Control signals are generated in response to the detected servo data which are transferred to a servo controller over a fully digital interface, thus obviating the analog-to-digital converter found in conventional servo controllers.

摘要翻译： 一种并入采样振幅读通道内的离散时间伺服解调技术，用于解调存储在磁介质上的嵌入式伺服场信息。 伺服字段信息由读取头转换为模拟信号，并转换为读通道中的一系列采样值。 解调技术响应于采样值，并且包括用于检测伺服数据的离散时间峰值检测器和用于测量伺服脉冲串幅度的离散时间伺服脉冲串幅度检测器。 通过从样本值序列感测斜率的变化，在模拟读取信号中检测峰。 峰由极性限定，只有当峰的极性与前一峰的符号相反时才检测到峰。 通过内插，整流和累加对应于伺服脉冲串的采样值序列来测量伺服脉冲串幅度。 多个寄存器将相应伺服脉冲串的振幅测量值存储在正交系统中，例如四个伺服脉冲串。 样本值被内插，平方，并且采样频率抖动，以便将脉冲串幅度测量的灵敏度降低到采样相位的变化并且增加用于伺服解调的读通道ADC的有效分辨率。 响应于通过全数字接口传送到伺服控制器的检测到的伺服数据产生控制信号，从而避免了在常规伺服控制器中发现的模拟 - 数字转换器。