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公开(公告)号：US09769547B2
公开(公告)日：2017-09-19
申请号：US12539691
申请日：2009-08-12
IPC分类号： H04Q9/00
CPC分类号： H04Q9/00 , H04Q2209/47 , H04Q2209/753
摘要： A method and apparatus are disclosed that apply multiuser detection (MUD) analysis to an aggregated RF response from a plurality of simultaneously queried RFID tags, so as to distinguish the individual tag responses. The claimed method thereby significantly reduces RFID detection latency when multiple tags are simultaneously queried. Some embodiments transmit carrier waves at more than one frequency, such as a plurality of equally-spaced frequencies, so as to enhance the MUD analysis by incorporating a multi-frequency dimension. Other embodiments incorporate additional spatial dimensions by deploying multiple RF detection antennae at separated locations. The number of colliding tag responses must be estimated before MUD analysis can be applied. In some embodiments other signal parameters must be estimated, such as signal bias and an impulse function for each responding tag that characterizes alterations of the RF signal while in transit due to propagation distance, passage through intervening objects, and reflections.
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2.发明申请METHOD FOR SIMULTANEOUS DETECTION OF A PLURALITY OF RFID TAGS USING MULTIUSER DETECTION 有权使用多媒体检测同时检测多个RFID标签的方法公开(公告)号：US20100039233A1
公开(公告)日：2010-02-18
申请号：US12539691
申请日：2009-08-12
IPC分类号： H04Q5/22
CPC分类号： H04Q9/00 , H04Q2209/47 , H04Q2209/753
摘要： A method and apparatus are disclosed that apply multiuser detection (MUD) analysis to an aggregated RF response from a plurality of simultaneously queried RFID tags, so as to distinguish the individual tag responses. The claimed method thereby significantly reduces RFID detection latency when multiple tags are simultaneously queried. Some embodiments transmit carrier waves at more than one frequency, such as a plurality of equally-spaced frequencies, so as to enhance the MUD analysis by incorporating a multi-frequency dimension. Other embodiments incorporate additional spatial dimensions by deploying multiple RF detection antennae at separated locations. The number of colliding tag responses must be estimated before MUD analysis can be applied. In some embodiments other signal parameters must be estimated, such as signal bias and an impulse function for each responding tag that characterizes alterations of the RF signal while in transit due to propagation distance, passage through intervening objects, and reflections.
摘要翻译： 公开了一种将多用户检测（MUD）分析应用于来自多个同时查询的RFID标签的聚合RF响应的方法和装置，以便区分各个标签响应。 因此，当多个标签被同时查询时，所要求保护的方法因此显着地降低了RFID检测等待时间。 一些实施例以多于一个频率（例如多个等间隔的频率）传送载波，以便通过并入多频维度来增强MUD分析。 其他实施例通过在分离的位置部署多个RF检测天线来并入额外的空间维度。 在应用MUD分析之前，必须估计碰撞标签响应的数量。 在一些实施例中，必须估计其他信号参数，例如每个响应标签的信号偏置和脉冲函数，其表征由于传播距离，通过中间对象和反射而在传输过程中RF信号的变化。
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公开(公告)号：US07936301B2
公开(公告)日：2011-05-03
申请号：US12459098
申请日：2009-06-26
IPC分类号： G01S13/06
CPC分类号： G01S7/032 , G01S13/34 , G01S13/885
摘要： A multi-port junction is fed with a frequency-stepped source and has one of its ports connected to an antenna that can serve either as a transmit-and-receive antenna or as a receive antenna only, with the outputs of the multi-port junction being used to estimate a complex reflection coefficient for each frequency of interest. The subject system requires no IF stages, down-conversion mixers or oscillators, and therefore may be provided adjacent each antenna at low cost. An embodiment involving co-located separate transmit and receive antennas is used to minimize the power requirements for the multi-port junction, whereas in a third embodiment, an array of transmit/receive antennas is used, fed by the same RF source but in which digitally-controlled phase shifters are used for beam-forming purposes.
摘要翻译： 一个多端口接头采用频率梯级电源，其一个端口连接到一个可以作为发射和接收天线或仅用作接收天线的天线，多端口的输出 结用于估计每个感兴趣频率的复反射系数。 主题系统不需要IF级，下变频混频器或振荡器，因此可以以低成本在每个天线附近提供。 使用涉及共同分开的发射和接收天线的实施例来最小化多端口结的功率需求，而在第三实施例中，使用由相同RF源馈送的发射/接收天线阵列，其中 数字控制移相器用于波束形成目的。
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公开(公告)号：US20090273507A1
公开(公告)日：2009-11-05
申请号：US12459098
申请日：2009-06-26
CPC分类号： G01S7/032 , G01S13/34 , G01S13/885
摘要： A multi-port junction is fed with a frequency-stepped source and has one of its ports connected to an antenna that can serve either as a transmit-and-receive antenna or as a receive antenna only, with the outputs of the multi-port junction being used to estimate a complex reflection coefficient for each frequency of interest. The subject system requires no IF stages, down-conversion mixers or oscillators, and therefore may be provided adjacent each antenna at low cost. An embodiment involving co-located separate transmit and receive antennas is used to minimize the power requirements for the multi-port junction, whereas in a third embodiment, an array of transmit/receive antennas is used, fed by the same RF source but in which digitally-controlled phase shifters are used for beam-forming purposes.
摘要翻译： 一个多端口接头采用频率梯级电源，其一个端口连接到一个可以作为发射和接收天线或仅用作接收天线的天线，多端口的输出 结用于估计每个感兴趣频率的复反射系数。 主题系统不需要IF级，下变频混频器或振荡器，因此可以以低成本在每个天线附近提供。 使用涉及共同分开的发射和接收天线的实施例来最小化多端口结的功率需求，而在第三实施例中，使用由相同RF源馈送的发射/接收天线阵列，其中 数字控制移相器用于波束形成目的。
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公开(公告)号：US07254511B2
公开(公告)日：2007-08-07
申请号：US11110264
申请日：2005-04-20
CPC分类号： H04B3/46 , G01R27/04 , G01R35/005
摘要： A calibration system is provided for calibrating frequency domain reflectometers in the field by using both the scattering parameters of the multi-port junction determined at the factory and changing the offset and gain terms used in generating a complex reflection coefficient by using internal calibrated loads so that heavy, cumbersome external calibrated transmission lines are not required. In one embodiment the internal calibrated loads include RLC circuits and in another embodiment the internal calibrated loads include attenuators. Further, retesting or recalibration does not necessitate reconnecting the cable under test, which may remain connected to the reflectometer's test port throughout the procedure.
摘要翻译： 提供了一种校准系统，用于通过使用出厂时确定的多端口结的散射参数和通过使用内部校准负载来改变用于产生复反射系数的偏移和增益项来校准现场的频域反射计，使得 不需要繁重繁琐的外部校准传输线。 在一个实施例中，内部校准负载包括RLC电路，在另一个实施例中，内部校准负载包括衰减器。 此外，重新测试或重新校准不需要重新连接被测电缆，这可能在整个过程中保持连接到反射计的测试端口。
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公开(公告)号：US07061221B2
公开(公告)日：2006-06-13
申请号：US11035311
申请日：2005-01-13
IPC分类号： G01R23/16
CPC分类号： G01R31/31717 , G01R27/04 , G01R27/32 , G01R31/11 , G01R35/005 , H04B3/46 , H04B3/493 , H04B3/56 , H04B2203/5425 , H04B2203/5483 , H04B2203/5491 , H04B2203/5495
摘要： A four-port junction is substituted for a six-port junction in a frequency domain reflectometer, which reduces the parts count and therefore cost and size of the reflectometer while improving reliability. The frequency domain reflectometer can alternatively be used as an insertion loss tester. An algorithm including the Hilbert Transform is used to directly calculate the estimated reflection coefficient from the output power measured at only two output ports.
摘要翻译： 四端口接头代替了频域反射计中的六端口结，这样可以降低零件数量，从而降低了反射计的成本和尺寸，同时提高了可靠性。 频域反射计可以替代地用作插入损耗测试仪。 包括希尔伯特变换在内的算法用于直接从仅在两个输出端口测量的输出功率计算估计的反射系数。
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7.发明授权公开(公告)号：US09814071B2
公开(公告)日：2017-11-07
申请号：US12742686
申请日：2009-09-25
IPC分类号： H04J1/00 , H04W74/08 , H04B1/7105 , H04L27/00 , H04W74/00
CPC分类号： H04W74/0833 , H04B1/7105 , H04L27/0006 , H04W74/002
摘要： A method is disclosed for increasing the communication capacity of a shared ad-hoc wireless channel by using multiuser detection (MUD) to distinguish overlapping information transmitted simultaneously by a plurality of nodes. The transmitting nodes simultaneously provide parameter-estimating signals over separate, unshared, low-rate parameter channels generated using orthogonal frequencies, spread spectrum technology, or time multiplexing. Receiving nodes use these separate, non-overlapping parameter-estimating signals to estimate MUD-required signal parameters such as amplitude, phase, and frequency offset, thereby enabling use of lower complexity MUD receivers, because the parameters are not estimated in the presence of other interference. Node ID, spreading code type, and/or other information can also be transmitted over the parameter channels. Limiting the number of parameter channels can limit the maximum number of transmitting nodes. Amplitudes of parameter channel transmissions can be greater than communication channel transmissions by a known ratio. Parameter channels can be frequency-hopped for jam-resistance.
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公开(公告)号：US07570200B2
公开(公告)日：2009-08-04
申请号：US11632027
申请日：2006-01-12
IPC分类号： G01S13/06
CPC分类号： G01S7/032 , G01S13/34 , G01S13/885
摘要： In the invention, a four-port junction (10) has a port (12) connected to an RF signal source (14). The four-port junction (10) also has an antenna port (16) coupled to a combined transmit/receive antenna (18). Two ports (20, 22) of the four-port junction (10) develop output power that is applied to an analogue-to-digital converter (24), that is in turn coupled to a central processor (26), that is in turn coupled to a user interface (28).
摘要翻译： 在本发明中，四端口结（10）具有连接到RF信号源（14）的端口（12）。 四端口结（10）还具有耦合到组合发射/接收天线（18）的天线端口（16）。 四端口结（10）的两个端口（20,22）产生施加到模拟 - 数字转换器（24）的输出功率，该模数转换器又耦合到中央处理器（26） 旋转耦合到用户界面（28）。
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公开(公告)号：US06947502B2
公开(公告)日：2005-09-20
申请号：US10228787
申请日：2002-08-26
CPC分类号： H04B1/71057 , H04B7/0851 , H04L1/06 , H04L1/20 , H04L1/24
摘要： A Parameter Estimator for accurately estimating signature responses of multiple co-channel interfering digital transmission signals. The Parameter Estimator is used in a Multiuser Detection (MUD) Receiver to significantly reduce the error rate. The Parameter Estimator comprises a plurality of software components, including a Signature Waveform Estimator, Training Sequence Locator, Noise Estimator, Active Users Tester, Initial Transformation Matrix Builder, a Transformation Matrix Rebuilder, and a Transformation Matrix Selector, and generates an estimated noise power, a training sequence index and estimated signature waveforms.
摘要翻译： 一种用于准确估计多个同信道干扰数字传输信号的签名响应的参数估计器。 参数估计器用于多用户检测（MUD）接收器，以显着降低错误率。 参数估计器包括多个软件组件，包括签名波形估计器，训练序列定位器，噪声估计器，主动用户测试器，初始变换矩阵生成器，变换矩阵重构器和变换矩阵选择器，并且产生估计的噪声功率， 训练序列索引和估计的签名波形。
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