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23 条记录 (耗时 0.019 秒)

    Time-varying Viterbi detector for control of error event length
    2.
    发明授权
    Time-varying Viterbi detector for control of error event length 失效
    用于控制误差事件长度的时变维特比检测器

    公开(公告)号：US5280489A

    公开(公告)日：1994-01-18

    申请号：US869570

    申请日：1992-04-15

    申请人： Lyle J. Fredrickson ,  Razmik Karabed ,  James W. Rae ,  Paul H. Siegel ,  Hemant K. Thapar ,  Roger W. Wood

    发明人： Lyle J. Fredrickson ,  Razmik Karabed ,  James W. Rae ,  Paul H. Siegel ,  Hemant K. Thapar ,  Roger W. Wood

    IPC分类号： H03M13/31 ,  G06F11/20 ,  H03M13/12

    CPC分类号： H03M13/31

    摘要： A method and apparatus for detecting spectral null sequences of a spectrally-constrained code on a noisy communications channel. From a Viterbi detector with a trellis structure comprising a plurality of states and edges, predetermined ones of the states and edges in the trellis structure are deleted at preselected times modulo N, such as times .phi. modulo N and/or at intermediate times m modulo N, where m=.phi., thereby to create a time-varying trellis structure for limiting the maximum length of dominant error events. The deleted edges are generally those edges which would have entered or emanated from the deleted states if they were not deleted. The trellis structure may be a so-called systolic structure, in which case the spectral null sequences are preferably DC-free or Nyquist free.

    摘要翻译： 一种用于检测噪声通信信道上的频谱约束码的频谱零序列的方法和装置。 从具有包括多个状态和边缘的网格结构的维特比检测器，网格结构中的预定的状态和边缘被预选为时间N，例如时间（phi）模N和/或中间时间m 模N，其中m =（phi），从而产生用于限制主要误差事件的最大长度的时变网格结构。 删除的边通常是那些从删除状态输入或发出的边缘，如果它们没有被删除。 网格结构可以是所谓的收缩结构，在这种情况下，光谱无效序列优选不含DC或奈奎斯特。

    Permuted trellis codes for input restricted partial response channels
    4.
    发明授权
    Permuted trellis codes for input restricted partial response channels 失效
    输入限制部分响应通道的格子码

    公开(公告)号：US5497384A

    公开(公告)日：1996-03-05

    申请号：US174904

    申请日：1993-12-29

    申请人： Lisa Fredrickson ,  Razmik Karabed ,  Paul H. Siegel ,  Hemant K. Thapar

    发明人： Lisa Fredrickson ,  Razmik Karabed ,  Paul H. Siegel ,  Hemant K. Thapar

    IPC分类号： H03M13/25 ,  H03M13/31 ,  H03M13/41 ,  G06F11/10 ,  H03M13/12

    CPC分类号： H03M13/6343 ,  H03M13/25 ,  H03M13/31 ,  H03M13/41 ,  H03M13/6502

    摘要： Maximum likelihood detection of a trellis code using a Viterbi detector constructed from a time-varying trellis structure that is associated with a partial response channel and consists of connected trellises with periodically repeated patterns of nodes and subtrellises of said trellises. Each subtrellis has nodes representing a current state of the channel and value of a predetermined tracked attribute. A survivor metric and a survivor sequence from a node at the end of one subtrellis are reassigned to a node at the beginning of an adjacent subtrellis having a different value of the tracked attribute for increasing minimum distance properties, reducing error event length and improving code constraints for timing and gain control. The one subtrellis and adjacent subtrellis may be within a single trellis or in adjacent trellises.

    摘要翻译： 使用由与部分响应信道相关联的时变网格结构构成的维特比检测器的网格码的最大似然检测，并且由具有所述网格的节点和子树的周期性重复模式的连接网格组成。 每个子伞具有表示通道的当前状态和预定跟踪属性的值的节点。 来自一个子结尾处的节点的幸存者度量和幸存者序列被重新分配给具有跟踪属性的不同值的相邻子树的开始处的节点，用于增加最小距离属性，减少错误事件长度和改进代码约束 用于定时和增益控制。 一个子伞和相邻的子伞可以在单个网格内或相邻的网格中。

    Even mark modulation coding method
    6.
    发明授权
    Even mark modulation coding method 失效
    偶标记调制编码方法

    公开(公告)号：US4870414A

    公开(公告)日：1989-09-26

    申请号：US169918

    申请日：1988-03-18

    申请人： Razmik Karabed ,  Paul H. Siegel

    发明人： Razmik Karabed ,  Paul H. Siegel

    IPC分类号： H04L25/08 ,  G11B20/10 ,  H03M5/14 ,  H03M13/23 ,  H04L25/49 ,  H04L25/497

    CPC分类号： G11B20/10009 ,  H03M5/145 ,  H04L25/4908 ,  H04L25/497

    摘要： A method termed Even Mark Modulation (EMM) is disclosed for coding input strings for input-restricted (1+D) or (1+D).sup.2 partial response channels that require at least one pair of consecutive signals of one state in order to record or transmit data to a receiving device. EMM provides improved coding gains and is especially suitable for optical recording.An input string is encoded into a binary code string in which all one-state signals (e.g., "1's") are in the form of runs of at least one contiguous pair; however, signals of an opposite state (e.g., "0's") may be of any length or duration. The EMM signals are detected with a maximum likelihood detector using an algorithm based on a three-state trellis structure for (1+D) channels and a five-state trellis structure for (1+D).sup.2 channels adapted to the particular partial response channel. In a preferred embodiment, the coding rate is 2/3 and the coding gain is at least 3 dB unnormalized and at least 2.2 dB when normalized. A finite-state encoder and sliding block decoder are disclosed, together with logic equations for encoder and decoder circuits.

    Phase invariant rate 8/10 matched spectral null code for PRML
    7.
    发明授权
    Phase invariant rate 8/10 matched spectral null code for PRML 失效
    PRML的相位不变率8/10匹配光谱空码

    公开(公告)号：US5095484A

    公开(公告)日：1992-03-10

    申请号：US747401

    申请日：1991-08-19

    申请人： Razmik Karabed ,  Paul H. Siegel

    发明人： Razmik Karabed ,  Paul H. Siegel

    IPC分类号： G11B20/10 ,  G11B20/14 ,  H03M13/31 ,  H04L25/49

    CPC分类号： G11B20/10055 ,  G11B20/10009 ,  G11B20/1426 ,  H03M13/31 ,  H04L25/4908 ,  G11B2020/1438

    摘要： A method for coding a binary data string for a partial-response channel having a transfer function with a spectral null at zero frequency to provide a coding rate 8/10 and an output which is invariant to 180-degree phase shifts in the channel output signal. A finite-state machine is created having two pairs of states and a plurality of codewords each corresponding to a respective binary data byte. The binary data string is encoded by said machine into a string of binary codewords having a power spectrum value of zero for a frequency of zero. In response to each successive data byte in the binary data string, there is generated one of two complementary codewords from the one of that pair of the states designated by said machine as corresponding to the data byte for the then current state of the machine. The sequence of said one complementary codewords is so decoded as to provide the same data output for said codeword sequence and its complement, irrespective of which of said complementary codewords was generated. The next state of said machine is preselected according to the value of the data byte and current state, and the next state for one element of a pair is the complement of the next state for the other element of the same pair.

    摘要翻译： 一种用于对具有零频率的频谱零点的传递函数的部分响应信道的二进制数据串进行编码的方法，以提供编码率8/10和对信道输出信号中的180度相移不变的输出 。 创建具有两对状态和多个码字的有限状态机，每个码字对应于相应的二进制数据字节。 二进制数据串由所述机器编码成频率为零的功率谱值为零的二进制码字串。 响应于二进制数据串中的每个连续的数据字节，从所述机器指定的一对状态中的一个中产生两个互补码字中的一个对应于机器的当前状态的数据字节。 所述一个互补码字的序列被解码为为所述码字序列及其补码提供相同的数据输出，而与所生成的所述互补码字中的哪一个无关。 根据数据字节和当前状态的值预先选择所述机器的下一状态，并且一对的一个元件的下一状态是相同对的另一元件的下一状态的补码。

    Method and apparatus for asymmetrical RLL coding
    8.
    发明授权
    Method and apparatus for asymmetrical RLL coding 失效
    用于不对称RLL编码的方法和装置

    公开(公告)号：US4949196A

    公开(公告)日：1990-08-14

    申请号：US175171

    申请日：1988-03-30

    申请人： Neil R. Davie ,  Martin A. Hassner ,  Thomas D. Howell ,  Razmik Karabed ,  Paul H. Siegel

    发明人： Neil R. Davie ,  Martin A. Hassner ,  Thomas D. Howell ,  Razmik Karabed ,  Paul H. Siegel

    IPC分类号： H03M7/14 ,  G06T9/00 ,  G11B20/14 ,  H03M5/14

    CPC分类号： H03M5/145 ,  G06T9/005

    摘要： This disclosure concerns for generating asymmetrically constrained run-length-limited encoded data from a serialized binary string of 1's and 0's. The method comprises the steps of encoding the input data bits using a run-length-limited constraint in the form of M/N (d,k), where M is the number of input data bits, N is the number of output bits associated therewith, d is the minimum number of 0 data bits between adjacent data bit 1's, and k is the maximum number of 0 data bits between adjacent 1's; and alternating the values of d and k between a set (d.sub.1, k.sub.1) and a set (d.sub.2, k.sub.2), respectively, where d.sub.1 .noteq.d.sub.2. The apparatus comprises means for generating N output data bits in response to M input data bits and for generating data bit 0's between data bit 1's based upon a run-length-limited coding constraints (d.sub.1, k.sub.1) and (d.sub.2, k.sub.2), where constraints (d.sub.1, k.sub.1) and (d.sub.2, k.sub.2) apply alternately to runs of zeroes between output data ones. Fractional numerical values of d.sub.1 and d.sub.2 can be employed in the method or apparatus.

    摘要翻译： 本公开涉及从1和0的串行化二进制串生成不对称约束的游程长度限制编码数据。 该方法包括以M / N（d，k）形式的游程限制约束对输入数据比特进行编码的步骤，其中M是输入数据比特数，N是相关联的输出比特数 因此，d是相邻数据位1之间的0个数据位的最小数量，k是相邻1之间的0个数据位的最大数量; 并且分别在集合（d1，k1）和集合（d2，k2）之间交替d和k的值，其中d1 NOTEQUAL d2。 该装置包括用于响应于M个输入数据位产生N个输出数据位并用于基于游程长度限制编码约束（d1，k1）和（d2，k2）在数据位1之间产生数据位0的装置，其中 约束（d1，k1）和（d2，k2）交替应用于输出数据之间的零运行。 d1和d2的分数值可以在该方法或装置中使用。

    Matched spectral null trellis codes for partial response channels
    9.
    发明授权
    Matched spectral null trellis codes for partial response channels 失效
    部分响应通道的匹配光谱空格状码

    公开(公告)号：US4888779A

    公开(公告)日：1989-12-19

    申请号：US169920

    申请日：1988-03-18

    申请人： Razmik Karabed ,  Paul H. Siegel

    发明人： Razmik Karabed ,  Paul H. Siegel

    IPC分类号： G11B20/10 ,  H03M13/23 ,  H04L25/08 ,  H04L25/49 ,  H04L25/497

    CPC分类号： H04L25/497

    摘要： A method is disclosed for coding input strings for a partial response channel to provide an output having a reliability determined by a preselectable coding gain. This method involves determining each frequency at which there is a zero in the transfer function of the partial response channel, and then encoding an input string into a binary code string having a power spectrum value of zero for each such frequency. A channel output sequence is generated responsively to transmission of the code string through the channel. The most probable sequence among those having a power spectrum value of zero is then calculated from the channel output sequence and decoded to provide the output.