公开(公告)号：US5060088A

公开(公告)日：1991-10-22

申请号：US372722

申请日：1989-06-28

申请人： Francois B. Dolivo ,  Sedat Oelcer ,  Andreas Rungeler ,  Wolfgang H. Schott

发明人： Francois B. Dolivo ,  Sedat Oelcer ,  Andreas Rungeler ,  Wolfgang H. Schott

IPC分类号： G11B5/035 ,  G11B20/10 ,  G11B20/18 ,  H03H15/00 ,  H03H17/00 ,  H03H21/00 ,  H04B3/04 ,  H04L25/03 ,  H04L27/01 ,  G11B5/09

CPC分类号： H03H21/0012 ,  G11B20/10009 ,  G11B5/035

摘要： The channel characteristics of magnetic-disk storage devices vary with track radius. An adaptive three-tap transversal equalizer that compensates these variations for systems using partial-response signaling is presented. The equalizer coefficients are updated by applying a procedure that is related to the recursive least-squares algorithm. This new updating procedure does not require multiplications and is well suited for high-speed implementation. Results obtained by computer simulations and measurements with a prototype have shown that the proposed adaptive equalizer can effectively compensate variations in magnetic-disk channel characteristics with track radius.

公开(公告)号：US4646173A

公开(公告)日：1987-02-24

申请号：US744106

申请日：1985-06-12

申请人： Karl-Dirk Kammeyer ,  Andreas Rungeler

发明人： Karl-Dirk Kammeyer ,  Andreas Rungeler

IPC分类号： H04L7/00 ,  H04L7/02 ,  H04L27/38 ,  G11B5/09 ,  G11B5/00 ,  H04B1/10

CPC分类号： H04L7/0029 ,  H04L27/38 ,  H04L7/0062

摘要： Multi-phase/multi-level modulation data signals recorded on tape after conversion from original digital data are first converted to complex digital signals in an analog-to-digital converter in which the sampling rate is set by a pulse generator frequency controlled by the received signals through a control loop which develops a frequency control voltage (A). The complex digital signals have their real and imaginary parts separately filtered by filters of variable propagation time, but of constant bandwidth to produce complex signals to which the nearest permissible output complex signal (reference signal) is selected by a decision circuit (17), for final conversion to binary signals by a decoder (19) and a shift register (20). Timing shift correction is based on comparison of the received signals and reference signals of the decision stage to produce a control signal (.phi.) which further processed by addition to its previous value to produce a timing correction signal (A) which is applied both to the pulse generator for the sampling frequency of the analog-to-digital converter and to control the propagation time of digital non-recursive filters (14, 15). The timing correction signal (A) control of the filter propagation time makes possible a rapid timing shift correction that overcomes tape jitter effects. It is not necessary to stabilize the received carrier frequency because the tap recording preserves the relation between the sampling/keying frequency and the carrier frequency.

摘要翻译： 在从原始数字数据转换之后记录在磁带上的多相/多电平调制数据信号首先在模数转换器中转换为复数数字信号，其中采样速率由接收到的脉冲发生器频率 通过产生频率控制电压（A）的控制回路发出信号。 复数数字信号通过可变传播时间的滤波器分别对其实部和虚部进行滤波，但是具有恒定带宽以产生由决策电路（17）选择最接近的允许输出复信号（参考信号）的复数信号，为 由解码器（19）和移位寄存器（20）最终转换为二进制信号。 定时移位校正基于接收信号和判决级的参考信号的比较，以产生通过加上其先前值进一步处理的控制信号（phi），以产生定时校正信号（A），该定时校正信号（A）同时应用于 脉冲发生器，用于模拟 - 数字转换器的采样频率，并控制数字非递归滤波器（14,15）的传播时间。 定时校正信号（A）控制滤波器传播时间使得可以实现克服磁带抖动效应的快速定时偏移校正。 不需要稳定接收的载波频率，因为抽头记录保持采样/键控频率与载波频率之间的关系。