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公开(公告)号：US5570396A
公开(公告)日：1996-10-29
申请号：US240041
申请日：1994-05-06
CPC分类号： H04L7/0062
摘要： In a digital symbol receiver it is necessary to generate a clock signal with a correct frequency and phase, so that decisions a.sub.k about the value of transmitted symbols a.sub.k can be made at the right detection instants. A simple method of obtaining the desired clock signal is to adjust a VCO by means of a control signal obtained from the correlation of a detection signal r(t) with the detected symbols a.sub.k filtered by a symbol filter. The symbol filter may comprise a cascade connection of a differentiator and a filter which has a transfer function which is an estimate of the transfer function of a channel which supplies the transmitted symbols.
摘要翻译： 在数字符号接收机中，必须产生具有正确频率和相位的时钟信号，从而可以在正确的检测时刻进行关于发送符号ak的值的判决+ E，cir a + EE k。 获得期望的时钟信号的简单方法是通过从检测信号r（t）与由符号滤波器滤波的检测符号+ E，cir a + EE k的相关性获得的控制信号来调整VCO。 符号滤波器可以包括微分器和滤波器的级联连接，滤波器具有作为提供发送符号的信道的传递函数的估计的传递函数。
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公开(公告)号：US5557638A
公开(公告)日：1996-09-17
申请号：US212669
申请日：1994-03-10
申请人： Kevin D. Fisher , Ho W. Wong-Lam , Johannes W. M. Bergmans , Frits A. Steenhof , Johannes O. Voorman
发明人： Kevin D. Fisher , Ho W. Wong-Lam , Johannes W. M. Bergmans , Frits A. Steenhof , Johannes O. Voorman
IPC分类号： H04L25/03 , H03K5/08 , H03M13/23 , H04L25/06 , H04L25/12 , H04L25/30 , H04L25/34 , H04L25/49
CPC分类号： H03K5/088 , H04L25/061 , H04L25/12
摘要： In a digital transmission system including a transmitter (2) coupled via a channel (4) to a receiver (6) a detection signal r.sub.k is compared with a number of reference values to determine the destination symbols a.sub.k. Since the size of the received signal r.sub.k is not known in advance, the ratio between the detection signal and the reference values is to be determined by an adapting circuit (16) on the basis of the received signal and the decisions made. The problem may then occur that as a result of an initially erroneous value of the ratio between detection signal and reference values not a correct adaptation is made. By recognizing such a situation because specific values of the symbols a.sub.k are lacking, in such a situation said ratio can be brought to such a value by the correction circuit (18) that all the values of a.sub.k again occur.
摘要翻译： 在包括经由信道（4）耦合到接收机（6）的发射机（2）的数字传输系统中，将检测信号rk与多个参考值进行比较，以确定目的地符号+ E，cir a + EE k。 由于接收信号rk的大小预先不知道，所以检测信号与参考值之间的比率将由适配电路（16）根据接收到的信号和作出的决定来确定。 然后可能出现这样的问题，即由于检测信号和参考值之间的比率的最初错误的值不是正确的适应。 通过识别这种情况，因为缺少符号+ E，cir a + EE k的特定值，在这种情况下，可以通过校正电路（18）使所述比值达到这样的值，即所有的+ E， 再次出现cir a + EE k。
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公开(公告)号：US5461644A
公开(公告)日：1995-10-24
申请号：US86814
申请日：1993-07-02
CPC分类号： H03M13/6502 , H03M13/41
摘要： Viterbi detector for a channel having a memory length 1, where no more than two survivors with an associated difference metric are updated. In the prior-art Viterbi detector of this type the new difference metric is from the previous difference metric by use of a saturation function. If the channel parameters differ from the values assumed for the calculation of the difference metric, the performance of the prior-art detector will rapidly degrade. In the detector according to the invention the new difference metric is derived from a combination of the saturation function of the previous difference metric and a correction signal which is a measure for the channel parameter difference.
摘要翻译： 用于具有存储器长度1的通道的维特比检测器，其中不超过具有相关差异度量的两个幸存者被更新。 在这种类型的现有维特比检测器中，新的差异度量是通过使用饱和函数从先前的差值度量。 如果信道参数与计算差值度量的值不同，则现有技术检测器的性能将迅速降低。 在根据本发明的检测器中，新的差异度量是从先前差值度量的饱和函数和作为信道参数差的度量的校正信号的组合导出的。
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4.发明授权Fast acquisition method for obtaining data from a transmission channel and a data receiver for carrying out this method 失效用于从传输信道获得数据的快速获取方法和用于执行该方法的数据接收机
公开(公告)号：US6118833A
公开(公告)日：2000-09-12
申请号：US919051
申请日：1997-08-27
CPC分类号： G11B20/10055 , G11B20/10009 , G11B20/1403 , G11B27/3027 , H04L7/041 , H04L7/10 , H04L7/0004 , H04L7/0062
摘要： A fast acquisition method is described that combines timing, gain and, if required, equalizer acquisition in one go with word synchronization. At the heart of the method is a preamble that begins with a repetition of identical words P whose length matches the code-word length. Preferably the method ends with a frame-sync word based on the bit-by-bit inverse of P. Main attractions of the technique are simplicity, speed, and robustness.
摘要翻译： 描述了一种快速捕获方法，其将时序，增益以及如果需要的话，均衡器采集与字同步结合在一起。 该方法的核心是以长度与码字长度匹配的相同字P的重复开始的前导码。 优选地，该方法基于P的逐位倒数以帧同步字结束。该技术的主要吸引力是简单性，速度和鲁棒性。
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公开(公告)号：US5131011A
公开(公告)日：1992-07-14
申请号：US545308
申请日：1990-06-26
CPC分类号： H04L25/03337
摘要： Non-linear intersymbol interference and noise in a received data signal are corrected through use of a Viterbi detector which estimates the most likely sequence of transmitted data symbols by keeping track of candidate data sequence that are recursively updated, based on likelihood measures which are determined by a signal processor which includes circuits for estimating hypothesized channel outputs in the absence of noise. Non-linear input-output relations are stored in one or more look-up tables which, in a preferred embodiment, are registers that store hypothesized channel output symbols in the absence of noise. The contents of the look-up tables may be modified in response to an error signal representative of the difference of the channel output signal and the look-up table output signal.
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6.发明授权Method and device utilizing erasure information as a reliability indicator in an information medium 失效在信息介质中使用擦除信息作为可靠性指示符的方法和装置
公开(公告)号：US6134065A
公开(公告)日：2000-10-17
申请号：US709500
申请日：1996-09-06
CPC分类号： G11B20/182 , G11B27/36
摘要： A method and a device in which information is written on a medium and is read out, and which establishes whether the information read is sufficiently reliable, and in which so-called erasure information is used to establish the influence of media defects and other imperfections on the occurrence of errors in a transmission system. The medium is, for example, a hard disk containing one or more bad spots whose location can be accurately detected. The implementation of the method makes accurate and fast computation of the bit error rate possible.
摘要翻译： 一种方法和装置，其中信息被写在介质上并被读出，并确定读取的信息是否足够可靠，并且使用所谓的擦除信息来建立媒体缺陷和其他缺陷的影响 在传输系统中发生错误。 该介质例如是包含一个或多个可以准确检测位置的不良点的硬盘。 该方法的实现使得误码率的准确和快速计算成为可能。
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公开(公告)号：US5463654A
公开(公告)日：1995-10-31
申请号：US98673
申请日：1993-07-28
CPC分类号： H04L25/03006
摘要： In a data receiver (6) a detection means (10) is used for determining a symbol value from the received signal. For reducing the effect of cyclostationary noise signals, a number of simultaneously operating detectors (12, 14) are used which derive a sequence of symbols from the input signal sampled at different instants. On the basis of a reliability measure simultaneously derived by the detectors, the symbol sequence whose associated reliability measure expresses the greatest reliability is conveyed to the output of the receiver with the aid of selection means.
摘要翻译： 在数据接收器（6）中，检测装置（10）用于从接收信号确定符号值。 为了减少循环平稳噪声信号的影响，使用多个同时操作的检测器（12,14），其从不同时刻采样的输入信号中导出符号序列。 基于由检测器同时导出的可靠性度量，其可靠性测量表达最大可靠性的符号序列借助于选择装置被传送到接收器的输出。
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8.发明授权
公开(公告)号：US5311558A
公开(公告)日：1994-05-10
申请号：US848810
申请日：1992-03-10
CPC分类号： H04B3/23
摘要： For reducing the complexity of adaptive systems such as equalizers, echo cancellers and clock recovery systems, errors are often determined only once per n samples, where n is an integer. If the input signal of such an adaptive system comprises cyclostationary components, it may occur that the adaptive system does not converge to a desired value. By selecting n in such a way that the greatest common divisor of n and the cyclostationary period m of the input signal is equal to 1, convergence of the adaptive system is ensured.
摘要翻译： 为了降低诸如均衡器，回波消除器和时钟恢复系统之类的自适应系统的复杂性，通常每n个采样器只确定一次错误，其中n是一个整数。 如果这种自适应系统的输入信号包括循环平稳组件，则可能发生自适应系统不会收敛到期望值。 通过以n的最大公约数和输入信号的周期平稳周期m等于1的方式选择n，确保了适应系统的收敛。
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9.发明授权Data transmission system comprising a decision feedback equalizer and using partial-response techniques 失效数据传输系统包括判决反馈均衡器和部分响应技术
公开(公告)号：US4866736A
公开(公告)日：1989-09-12
申请号：US203655
申请日：1988-06-07
IPC分类号： H04B3/06 , H04L25/03 , H04L25/497
CPC分类号： H04L25/03057 , H04L25/066
摘要： A system for transmitting an n-level data signal (d.sub.k) at a given symbol rate 1/T comprises a data transmitter (1), a transmission channel (2) and a data receiver (3) with an equalizer (30) of the decision feedback type. By arranging this equalizer (30) for forming an estimate (c.sub.k) of a virtual m-level data signal (c.sub.k) instead of the output signal (b.sub.k) of the data transmitter (1) error propagation in the equalizer (30) is considerably reduced without thereby appreciably adding to the implementation-complexity of the system.
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公开(公告)号：US6091558A
公开(公告)日：2000-07-18
申请号：US909919
申请日：1997-08-12
CPC分类号： G11B20/10212
摘要： A device for write precompensation of data signals to be recorded on a magnetic medium, which device has an input for receiving input data signals and an output for supplying output signals to be recorded, an integrator/limiter circuit which receives the input data signals and which supplies an output signal which is in synchronism with the data signal and whose amplitude varies substantially linearly as a function of time at positions where a signal transition appears in the data signal, which amplitude is limited within a data symbol interval; an adjustable filter which receives the input signals and supplies an output signal whose instantaneous values depend on the pattern of preceding and future signal transitions in the data signal; and a comparator circuit which through comparison of the output signal of the integrator/limiter circuit and the output signal of the filter produces the output signal in which at least some signal transitions of the input data signal can be shifted in time. An important aspect of the present invention is that with the output signal dt an arbitrary number of desired time shifts can be obtained rather than that, as in the prior art, only a choice can be made from a limited number of delay values.
摘要翻译： 一种用于写入预记录在磁介质上的数据信号的装置，该装置具有用于接收输入数据信号的输入端和用于提供要记录的输出信号的输出端，接收输入数据信号的积分器/限幅电路，以及哪个 提供与数据信号同步的输出信号，其幅度随着数据信号中出现信号转变的位置处的时间的函数而基本线性变化，该幅度被限制在数据符号间隔内; 可调滤波器，其接收输入信号并提供其瞬时值取决于数据信号中的先前和未来信号转换的模式的输出信号; 并且通过比较积分器/限幅器电路的输出信号和滤波器的输出信号的比较器电路产生其中输入数据信号的至少一些信号转换可以及时移位的输出信号。 本发明的一个重要方面是，通过输出信号dt，可以获得任意数量的期望时间偏移，而不是象现有技术那样，只能从有限数量的延迟值中进行选择。
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