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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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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：US07190747B2
公开(公告)日：2007-03-13
申请号：US10423695
申请日：2003-04-25
IPC分类号： H04L27/06
CPC分类号： H04L1/005 , H04B1/7107 , H04L1/0048 , H04L1/06 , H04L25/03171 , H04L27/0014 , H04L2027/0055 , H04L2027/0067
摘要： Techniques for compensating for frequency mismatch between transmitters and receivers of a multiuser communication system having a plurality of users are disclosed. In particular, the mismatch of carrier frequency estimates are estimated and compensated for each user of the system. This is accomplished without increasing the training overhead of the system. Symbol phase drift and offset is computed by estimating phase error profile parameters (e.g., slope and offset). The disclosed techniques may be used to correct for symbol rotation in any one decision region, or in neighboring decision regions.
摘要翻译： 公开了一种用于补偿具有多个用户的多用户通信系统的发射机和接收机之间的频率失配的技术。 特别地，针对系统的每个用户估计和补偿载波频率估计的不匹配。 这是在不增加系统的培训开销的情况下实现的。 通过估计相位误差轮廓参数（例如，斜率和偏移）来计算符号相位漂移和偏移。 所公开的技术可以用于校正任何一个决策区域或相邻决策区域中的符号旋转。
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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：US20120051475A1
公开(公告)日：2012-03-01
申请号：US12869875
申请日：2010-08-27
申请人： Brandon P. Hombs , John A. Tranquilli, JR. , Joseph A. Farkas , Leonard E. Russo , Joshua D Niedzwiecki
发明人： Brandon P. Hombs , John A. Tranquilli, JR. , Joseph A. Farkas , Leonard E. Russo , Joshua D Niedzwiecki
IPC分类号： H04B1/10
CPC分类号： H03H21/0012 , H03H2021/005 , H03H2021/0052 , H03H2220/04
摘要： A QR-RLS adaptive digital filter provides fast computation without excessive computational resources. 18-bit multipliers enhance speed, and a floating point inverse square root block adjusts dynamic range in 12-dB steps. A memory stores two P-matrix copies, one being delivered with rows shifted according to the clock speed so as to enhance pipeline processing. Embodiments reliably detect modulation schemes, demodulate strong signals by passing feedback bits between multiple stages, remove impulses due to lightening, etc, erase symbol estimates which exceed an error threshold, and add high frequency noise to avoid mathematical divergence caused by excessive S/N. A genetic method is provided for identifying asynchronous spreading codes with minimum correlations, whereby randomly selected candidates compete based on Frobenius norms of their correlations, the weakest being discarded and the process being iterated. A method is provided for selecting optimal filter sampling windows for simultaneously detected symbol streams having relative timing delays.
摘要翻译： QR-RLS自适应数字滤波器提供快速计算而不需要过多的计算资源。 18位乘法器提高速度，并且浮点反平方根块以12分贝的步长调整动态范围。 存储器存储两个P矩阵副本，一个被传送，根据时钟速度移位，以便增强流水线处理。 实施例可靠地检测调制方案，通过在多级之间传递反馈比特来解调强信号，消除由于减轻引起的脉冲等，消除超过误差阈值的符号估计，并且增加高频噪声以避免由于过大的S / N引起的数学发散。 提供遗传方法用于识别具有最小相关性的异步扩展码，由此随机选择的候选者基于其相关性的Frobenius规范进行竞争，最弱的被舍弃并且迭代的过程。 提供了一种用于选择用于具有相对定时延迟的同时检测到的符号流的最佳滤波器采样窗口的方法。
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7.发明申请MEDIA ACCESS CONTROL PROTOCOL FOR MULTIUSER DETECTION ENABLED AD-HOC WIRELESS COMMUNICATIONS 有权用于多媒体检测的媒体访问控制协议启用的无线通信公开(公告)号：US20110051674A1
公开(公告)日：2011-03-03
申请号：US12742686
申请日：2009-09-25
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.
摘要翻译： 公开了一种用于通过使用多用户检测（MUD）来增加共享自组织无线信道的通信能力来区分由多个节点同时发送的重叠信息的方法。 发射节点通过使用正交频率，扩频技术或时间复用产生的分开的，非共享的，低速率的参数信道同时提供参数估计信号。 接收节点使用这些分离的非重叠参数估计信号来估计MUD所需的信号参数，例如振幅，相位和频率偏移，从而使得能够使用较低复杂度的MUD接收机，因为参数在其他情况下不被估计 干扰。 节点ID，扩展码类型和/或其他信息也可以通过参数信道发送。 限制参数通道的数量可以限制发送节点的最大数量。 参数信道传输的幅度可以通过已知比率大于通信信道传输。 参数通道可跳频阻抗。
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8.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：US07613228B2
公开(公告)日：2009-11-03
申请号：US11463877
申请日：2006-08-10
申请人： Joshua D Niedzwiecki
发明人： Joshua D Niedzwiecki
IPC分类号： H04B1/00
CPC分类号： H04B1/7105 , H04L1/005 , H04L25/0204 , H04L25/0246 , H04L25/03171 , H04L25/03184 , H04L25/03216 , H04L25/0328 , H04L25/03292 , H04L25/03299 , H04L25/03331
摘要： A multiuser detector system with correlation based pruning including a parameter estimation module adapted to receive complex signals, and to produce estimated signature waveforms for each of K co-channel interfering signals. Pre-processing the estimated signature waveforms using an S-matrix module and producing a more valid set of hypotheses, wherein the S-matrix module uses apriori knowledge of an unnormalized cross correlation matrix, and processing the more valid set of hypotheses for pruning with an M-algorithm in a multiuser detector module. An improvement to the M-algorithm in which the interference structure based on the signal correlation matrix used during the optimization process aids in selecting a better subset of hypotheses to test. This approach has the benefit of reducing computational complexity and improving performance over the existing M-algorithm.
摘要翻译： 一种具有基于相关的修剪的多用户检测器系统，包括适于接收复杂信号的参数估计模块，并且为K个同频道干扰信号中的每一个产生估计的签名波形。 使用S矩阵模块预处理估计的签名波形并产生更有效的假设集合，其中S矩阵模块使用非规范化互相关矩阵的先验知识，并且处理用于修剪的更有效的假设集合 多用户检测器模块中的M算法。 对M算法的改进，其中基于在优化过程中使用的信号相关矩阵的干扰结构有助于选择更好的假设子集进行测试。 这种方法有利于降低计算复杂度并提高现有M算法的性能。
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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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