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1.发明授权Method and apparatus for reducing near-end crosstalk (NEXT) in discrete multi-tone modulator/demodulators 失效用于减少离散多音调制器/解调器中的近端串扰（NEXT）的方法和装置公开(公告)号：US06678316B1
公开(公告)日：2004-01-13
申请号：US09658570
申请日：2000-09-08
IPC分类号： H04B138
CPC分类号： H04L5/14 , H04L27/2607 , H04L27/2656 , H04L27/2678
摘要： Near-end crosstalk between identical discrete multi-tone modems is reduced by aligning the frames of all modems at a central office to each other, aligning the frames transmitted by subscribers' modems with the frames received by those modems, and including a cyclic prefix between the central office and the most distant subscriber to be served. By making adjacent DMT carrier frequencies be orthogonal to each other, the aforementioned modifications will reduce both Near End Cross-Talk and Leakage-Excited Cross-Talk. These benefits apply to modems at both the central office and subscriber ends of the communication path.
摘要翻译： 通过将中心局的所有调制解调器的帧彼此对准，将用户调制解调器发送的帧与由这些调制解调器接收的帧对齐，并且包括在两个调制解调器之间的循环前缀，减少相同离散多音调制解调器之间的近端串扰 中央办公室和最远的订户。 通过使相邻的DMT载波频率彼此正交，上述修改将减少近端串话和泄漏激励的对话。 这些优点适用于通信路径的中心局和用户端的调制解调器。
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2.发明授权Method and apparatus for reducing near-end crosstalk (NEXT) in discrete multi-tone modulator/demodulators 失效用于减少离散多音调制器/解调器中的近端串扰（NEXT）的方法和装置
公开(公告)号：US6144695A
公开(公告)日：2000-11-07
申请号：US997176
申请日：1997-12-23
CPC分类号： H04L5/14 , H04L27/2607 , H04L27/2656 , H04L27/2678
摘要： This invention reduces near-end crosstalk between identical discrete multi-tone (DMT-type) modems by introducing the following modifications to modems at a central office or a subscriber premises. The modifications include: a mechanism for aligning the frames of all modems at the central office (CO), a mechanism for aligning the frames transmitted by the subscribers' modems with the frames received by those modems, and lengthening the DMT frame to include a cyclic prefix. The cyclic prefix to a frame has been made longer than twice the maximum round-trip delay, that is, the delay between the central office and the most distant subscriber to be served. By making adjacent DMT carrier frequencies be orthogonal to each other, the aforementioned modifications will reduce both Near End Cross-Talk (NEXT) and Leakage-Excited Cross-Talk (LEXT). These benefits apply to modems at both the central office (CO) and subscriber ends of the communication path (for example, a high capacity twisted-pair wire).
摘要翻译： 本发明通过在中心局或用户房屋处对调制解调器引入以下修改来减少相同离散多音调（DMT型）调制解调器之间的近端串扰。 这些修改包括：用于对准中央局（CO）处的所有调制解调器的帧的机制，用于将由用户调制解调器发送的帧与由这些调制解调器接收的帧对准的机制，以及延长DMT帧以包括循环 字首。 帧的循环前缀已经被设置为比最大往返延迟的两倍，即中心局和要服务的最远的用户之间的延迟。 通过使相邻的DMT载波频率彼此正交，上述修改将减少近端串话（NEXT）和泄漏激励对讲（LEXT）。 这些优点适用于中央局（CO）和通信路径的用户端（例如，高容量双绞线）的调制解调器。
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3.发明授权公开(公告)号：US06236315B1
公开(公告)日：2001-05-22
申请号：US09421867
申请日：1999-10-19
IPC分类号： G08B1314
CPC分类号： G08B13/2488 , G06K7/0008 , G08B13/2417 , G08B13/2462 , G08B13/2471 , H01Q21/29
摘要： A method for increasing the interrogation range of an RF Tag in a radio communication system using RF Tags with two reflecting antenna elements. The second reflecting antenna element is predeterminately positioned, and preferably aligned, with respect to the first reflecting antenna element in the direction of expected incident RF radiation and is spaced from the first reflecting antenna element at a predetermined fixed distance. The first and second reflecting antenna elements are alternately pulsed on and off such that while the first reflecting antenna element is in a signal reflecting operating state, the second reflecting antenna element is in a substantially non-reflecting state and vice versa. The alternate pulsing and predetermined fixed spacing between the first and second elements generates a known phase difference between the reflected signals of the first and second reflecting antenna elements. The phase difference is preferably 180 degrees which may be achieved by spacing the second reflecting antenna element from the first reflecting antenna element at a distance equivalent to ¼ of the wavelength of the interrogating signals.
摘要翻译： 一种在具有两个反射天线元件的RF标签的无线电通信系统中增加RF标签的询问范围的方法。 第二反射天线元件相对于第一反射天线元件在预期的入射RF辐射的方向上被预先定位并且优选地对准，并且以预定的固定距离与第一反射天线元件间隔开。 第一反射天线元件和第二反射天线元件交替脉冲地通过和关闭，使得当第一反射天线元件处于反映操作状态的信号时，第二反射天线元件处于基本上非反射状态，反之亦然。 第一和第二元件之间的交替脉冲和预定的固定间隔产生第一和第二反射天线元件的反射信号之间已知的相位差。 相位差优选为180度，这可以通过将第二反射天线元件与第一反射天线元件间隔在等于询问信号的波长的1/4的距离来实现。
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公开(公告)号：US06590498B2
公开(公告)日：2003-07-08
申请号：US09999390
申请日：2001-10-31
申请人： Howard David Helms
发明人： Howard David Helms
IPC分类号： G08B1314
CPC分类号： G08B13/2488 , G06K7/0008 , G08B13/2417 , G08B13/2462 , G08B13/2471 , H01Q21/29
摘要： A method for increasing the interrogation range of an RF Tag in a radio communication system using RF Tags with multiple reflecting antenna elements. The reflecting antenna elements are predeterminately positioned, and preferably aligned, with respect to each other in the direction of expected incident RF radiation. The reflecting antenna elements are sequentially pulsed on and off such that while the first reflecting antenna element is in a signal reflecting operating state, the remaining reflecting antenna elements are in a substantially non-reflecting state, and when the second reflecting element is in a reflecting operating state, the remaining reflecting elements are in a non-reflecting state, etc. The sequential pulsing and predetermined fixed spacing between the reflector elements generates constructive interference between the reflected signals of the reflecting antenna elements which increases the power of the resulting reflected signal.
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公开(公告)号：US06356569B1
公开(公告)日：2002-03-12
申请号：US09001581
申请日：1997-12-31
IPC分类号： H04J322
CPC分类号： H04J1/05 , H03H17/0213 , H03H17/0266
摘要： A digital channelizer employs a polyphase filter element in which a shift register is used to commutate time series data to a bank of polyphase filters at the inputs of an FFT module. The filter bank and FFT module are updated at a frequency that is independent of the rate that the data is fed into the buffer and filter/FFT cycle rates of less than the ratio of the input data rate to the number of input channels may be accommodated by the shift register commutation. The output of the FFT module is interpolation filtered by inserting interpolated points between adjacent data points in the channelized output stream to increase the output frequency by an integral multiple of the update rate of the polyphase filter/FFT update rate. By determining an integer, q, such that (Ro/Ri)(2N−q) is a non-zero integer l, where Ro is a desired output data rate, Ri is an input data rate and 2N is the number of output channels (M
摘要翻译： 数字信道化器采用多相滤波器元件，其中使用移位寄存器将时间序列数据转换成FFT模块的输入端的多相滤波器组。 滤波器组和FFT模块以与将数据馈送到缓冲器中的速率无关的频率更新，并且可以容纳小于输入数据速率与输入通道数量的比率的滤波器/ FFT周期速率 通过移位寄存器换向。 通过在通道化输出流中的相邻数据点之间插入插值点来对FFT模块的输出进行内插滤波，以将输出频率增加多相滤波器/ FFT更新速率的更新速率的整数倍。 通过确定整数q，使得（Ro / Ri）（2N-q）是非零整数l，其中Ro是期望的输出数据速率，Ri是输入数据速率，2N是输出信道的数量 （M
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