专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

1. 发明授权

US4376309A Method and apparatus for signal-eye tracking in digital transmission systems 失效
标题翻译：数字传输系统中信号眼跟踪的方法和装置
公开(公告)号：US4376309A
公开(公告)日：1983-03-08
申请号：US268274
申请日：1981-05-29
申请人： Gerald L. Fenderson , Mitchell A. Skinner
发明人： Gerald L. Fenderson , Mitchell A. Skinner
IPC分类号： H03M5/04 , H04L1/20 , H04L7/02 , H04L25/03 , H04L25/40 , H04L25/49 , H04L7/04
CPC分类号： H04L7/0062 , H04L1/20
摘要： An improvement in tracking the signal-eyes (FIG. 4) formed by a digital signal is disclosed. This improvement is achieved by forming a sample at a regeneration sampling time (e.g., 404), a first sampling time (e.g., 401) and a second sampling time (e.g., 402). The first and second sampling times respectively precede and succeed the signal-eyes while each regeneration sampling time occurs within the signal-eyes. The amplitude of each sample represents the amplitude of the digital signal at the sampling time relative to a reference level (e.g., 301, 302 or 303) which passes through one of the signal-eyes. A first comparison signal is generated by comparing the amplitudes of the samples at the regeneration and adjacent first sampling times. Similarly, a second comparison signal is generated by comparing the amplitudes of the samples at the regeneration and adjacent second sampling times. The difference between the first and second comparison signal is then averaged to form an error signal. The error signal varies with movement of the signal-eyes relative to the regeneration sampling time. In one embodiment (FIG. 2) of the invention, this error signal is used to align the regeneration sampling time with a predetermined position within the signal-eyes.
摘要翻译：公开了一种由数字信号形成的对信号眼（图4）进行跟踪的改进。通过在再生采样时间（例如404），第一采样时间（例如401）和第二采样时间（例如402）处形成采样来实现该改进。第一和第二采样时间分别在信号眼之前和之后，而每个再生采样时间发生在信号眼内。每个样本的幅度表示在采样时间相对于通过信号眼之一的参考电平（例如，301,302或303）的数字信号的振幅。通过比较在再生和相邻的第一采样时间的样本的幅度来产生第一比较信号。类似地，通过比较在再生和相邻的第二采样时间的样本的振幅来产生第二比较信号。然后对第一和第二比较信号之间的差进行平均以形成误差信号。误差信号随信号眼的移动相对于再生采样时间而变化。在本发明的一个实施例（图2）中，该误差信号用于将再生采样时间与信号眼内的预定位置对准。

2. 发明授权

US4993047A Volterra linearizer for digital transmission 失效
标题翻译： Volterra线性化数字传输
公开(公告)号：US4993047A
公开(公告)日：1991-02-12
申请号：US402750
申请日：1989-09-05
申请人： James P. Moffatt , Mitchell A. Skinner
发明人： James P. Moffatt , Mitchell A. Skinner
IPC分类号： H04L27/01 , H03F1/32 , H04B3/06 , H04B7/005 , H04L25/03 , H04L27/36 , H04L27/38
CPC分类号： H04L27/368 , H03F1/3223 , H04L27/3809 , H04L27/3872
摘要： Characterized nonlinearities in a QAM transmission channel are removed by this linearizer, in which selected bits from a sequence of received symbols on both rails form the address of a PROM. Stored values represent the Volterra expansion of the response of the channel, including the nonlinearity, to the symbol sequence. Symmetries in the Volterra expansion allow the same stored value to be used to correct both AM/AM same rail and AM/PM opposite rail distortion.

3. 发明授权

US4794623A Recovery of carrier signal from QAM double sideband suppressed carrier IF signal for use in synchronous demodulation 失效
标题翻译：从QAM双边带恢复载波信号抑制载波IF信号用于同步解调
公开(公告)号：US4794623A
公开(公告)日：1988-12-27
申请号：US63703
申请日：1976-06-12
申请人： Louis Y. Levesque , Mitchell A. Skinner
发明人： Louis Y. Levesque , Mitchell A. Skinner
IPC分类号： H03L7/087 , H03L7/10 , H04L27/38 , H03D3/22
CPC分类号： H03L7/087 , H03L7/10 , H04L27/3836
摘要： A novel circuit recovers a carrier signal from a 16 or 64 QAM double sideband suppressed carrier IF signal for use in synchronolus demodulation. A 70 MHz IF signal is fed to a power splitter for distributing the signals to a demodulator and to a quadrupler. The 280 MHz signal from the quadrupler is fed to a surface acoustic wave filter to extract the components of the double sideband suppressed carrier signal and the output therefrom is amplified prior to being divided by four to recover the 70 MHz signal. The 70 MHz signal is delivered to a phase frequency detector which provides an error signal during acquisition to deviate a VCO toward the received frequency and thus obtain very fast acquisition time. When the VCO is locked, the phase frequency detector is disconnected from the summing node of a PLL, and a correlated error polarity adaptive carrier recovery circuit operates the demodulator.
摘要翻译：一种新颖的电路从16或64 QAM双边带抑制载波IF信号中恢复载波信号，用于同步解调。 70MHz IF信号被馈送到功率分配器以将信号分配到解调器和四通道。来自四通路的280MHz信号被馈送到表面声波滤波器以提取双边带抑制载波信号的分量，并且其输出在被除以四之前被放大以恢复70MHz信号。 70MHz信号被传送到相位频率检测器，该相位频率检测器在采集期间提供误差信号以将VCO偏离接收的频率，从而获得非常快的采集时间。当VCO被锁定时，相位频率检测器与PLL的求和节点断开，相关的误差极性自适应载波恢复电路操作解调器。

4. 发明授权

US4326169A Adaptive decision level circuit 失效
标题翻译：自适应决策电路
公开(公告)号：US4326169A
公开(公告)日：1982-04-20
申请号：US127936
申请日：1980-03-07
申请人： Gerald L. Fenderson , Mitchell A. Skinner
发明人： Gerald L. Fenderson , Mitchell A. Skinner
IPC分类号： H03K5/08 , H04L25/03 , H04L25/06 , H04L25/49 , H03K5/22
CPC分类号： H04L25/065 , H03K5/086 , H04L25/063
摘要： The adaptive decision level circuit (FIG. 3) slices a digital signal with respect to a decision level disposed between the signal levels. A correction signal generated from the sliced signals (S, S) compensates for variations in the signal levels by maintaining the decision level at a constant position relative to the signal levels. The correction signal is generated by comparing (321) the integrated difference (on lead 305) between the sliced signal and its complement with the statistically expected value (312) of the difference between the sliced signal and its complement. In the preferred embodiment, the expected value is equal to one-half the signal swing of the sliced signal.
摘要翻译：自适应判决电平电路（图3）相对于设置在信号电平之间的判定电平划分数字信号。从切片信号（S，S）产生的校正信号通过将判定电平相对于信号电平维持在恒定位置来补偿信号电平的变化。校正信号通过将切片信号与其补码之间的积分差（在引线305上）与切片信号与其补码之间的差的统计期望值（312）进行比较（321）而产生。在优选实施例中，期望值等于切片信号的信号摆幅的一半。

你已经成功收藏专利！

检索式保存成功!

IPRDB

热门服务

关于我们

友情链接

联系方式