公开(公告)号：US08217760B2

公开(公告)日：2012-07-10

申请号：US12407383

申请日：2009-03-19

申请人： Ben J. Wild ,  Upamanyu Madhow ,  Kannan Ramchandran ,  Robert Barton ,  Artem Tkachenko

发明人： Ben J. Wild ,  Upamanyu Madhow ,  Kannan Ramchandran ,  Robert Barton ,  Artem Tkachenko

IPC分类号： H04Q5/22

CPC分类号： G01S3/14 ,  G01S7/003 ,  G01S13/74 ,  G06K7/10178

摘要： In an RFID system with existing reader and tags communicating with each other, appliqués derive information by listening to this communication to yield significant performance benefits, while not affecting the communication between the existing nodes. For example, an appliqué capable of receiving beamforming can estimate the angle of arrival of the signal emitted by a tag, thereby providing information that can be used to localize the tag. An appliqué may be connected to an existing reader by means of an existing port, such as to an antenna port or to an Ethernet port. The information from appliqués can be integrated with that obtained from existing nodes at either the appliqués, or further up the hierarchy in middleware.

摘要翻译： 在具有彼此通信的现有读取器和标签的RFID系统中，贴花通过监听该通信来获得信息，以产生显着的性能优点，同时不影响现有节点之间的通信。 例如，能够接收波束形成的贴布可以估计由标签发出的信号的到达角度，从而提供可用于本地化标签的信息。 贴布可以通过现有端口连接到现有的读取器，例如到天线端口或以太网端口。 来自贴花的信息可以与从贴片上现有节点获得的信息集成，也可以与中间件的层次结构进一步集成。

公开(公告)号：US08144668B1

公开(公告)日：2012-03-27

申请号：US12272364

申请日：2008-11-17

申请人： Upamanyu Madhow

发明人： Upamanyu Madhow

IPC分类号： H04B7/216 ,  H04B1/00 ,  H04J9/00 ,  H04J3/22

CPC分类号： H04B1/7103 ,  H04B1/709 ,  H04B1/71072

摘要： The present invention considers a direct sequence spread spectrum system wherein every user employs the same spreading code. In a preferred embodiment, received signal is correlated with the training signal. Peaks of correlator output are used to identify the delays corresponding to the significant multipath components. The delays that are within a predetermined number of chips of each other are associated with a hypothesized user. In an alternate embodiment, a user separation technique is used which is based on the observation that after the training period, different users send uncorrelated data. In another alternate embodiment, linear minimum mean squared error (LMMSE) based correlators locked to individual users are employed. These correlators only provide multipath components of their corresponding users as output.

摘要翻译： 本发明考虑了一种直接序列扩频系统，其中每个用户使用相同的扩展码。 在优选实施例中，接收信号与训练信号相关。 相关器输出的峰值用于识别对应于显着多径分量的延迟。 在预定数量的芯片之间的延迟与假设的用户相关联。 在替代实施例中，使用用户分离技术，其基于观察结果，在训练周期之后，不同的用户发送不相关的数据。 在另一个实施例中，采用了锁定到个人用户的基于线性最小均方误差（LMMSE）的相关器。 这些相关器仅提供其相应用户的多径分量作为输出。

公开(公告)号：US20100013601A1

公开(公告)日：2010-01-21

申请号：US12407383

申请日：2009-03-19

申请人： Ben J. Wild ,  Upamanyu Madhow ,  Kannan Ramchandran ,  Robert Barton ,  Artem Tkachenko

发明人： Ben J. Wild ,  Upamanyu Madhow ,  Kannan Ramchandran ,  Robert Barton ,  Artem Tkachenko

IPC分类号： G06K7/01

CPC分类号： G01S3/14 ,  G01S7/003 ,  G01S13/74 ,  G06K7/10178

摘要： In an RFID system with existing reader and tags communicating with each other, appliqués derive information by listening to this communication to yield significant performance benefits, while not affecting the communication between the existing nodes. For example, an appliqué capable of receiving beamforming can estimate the angle of arrival of the signal emitted by a tag, thereby providing information that can be used to localize the tag. An appliqué may be connected to an existing reader by means of an existing port, such as to an antenna port or to an Ethernet port. The information from appliquéscan be integrated with that obtained from existing nodes at either the appliqués, or further up the hierarchy in middleware.

摘要翻译： 在具有彼此通信的现有读取器和标签的RFID系统中，贴花通过监听该通信来获得信息，以产生显着的性能优点，同时不影响现有节点之间的通信。 例如，能够接收波束形成的贴布可以估计由标签发出的信号的到达角度，从而提供可用于本地化标签的信息。 贴布可以通过现有端口连接到现有的读取器，例如到天线端口或以太网端口。 来自appliquéscan的信息与从现有节点获得的信息集合在贴布上，或者在中间件的层次结构中进一步集成。

公开(公告)号：US5481533A

公开(公告)日：1996-01-02

申请号：US241928

申请日：1994-05-12

申请人： Michael L. Honig ,  Upamanyu Madhow

发明人： Michael L. Honig ,  Upamanyu Madhow

IPC分类号： H04B7/26 ,  H04J13/16 ,  H04B7/204 ,  H04B15/00 ,  H04J13/04 ,  H04L27/30

CPC分类号： H04J13/16 ,  H04B7/2618

摘要： In a cellular network, a multiple-access methodology and concomitant circuitry in which TDMA is used inside each cell and CDMA signals, having pulse shapes with low cross-correlations, are assigned to adjacent cells. For example, these pulses could be Direct-Sequence Spread-Spectrum pulses. Such a hybrid system combines the high intra-cell capacity of TDMA with the inter-cell and multipath interference rejection capabilities of CDMA.

摘要翻译： 在蜂窝网络中，在每个小区内使用TDMA的多址方法和伴随电路以及具有低互相关的脉冲形状的CDMA信号被分配给相邻小区。 例如，这些脉冲可以是直接序列扩频脉冲。 这样的混合系统将TDMA的高小区容量与CDMA的小区间和多径干扰抑制能力相结合。

公开(公告)号：US20100309017A1

公开(公告)日：2010-12-09

申请号：US12719126

申请日：2010-03-08

申请人： Kannan Ramchandran ,  Ben J. Wild ,  Artem Tkachenco ,  Upamanyu Madhow

发明人： Kannan Ramchandran ,  Ben J. Wild ,  Artem Tkachenco ,  Upamanyu Madhow

IPC分类号： G08B5/22

CPC分类号： G01S3/74 ,  G01S13/756

摘要： A localization method for use in a tag communication system includes associating a supertag having a plurality of tags with an item, reading backscatter signals from the tags of the plurality of tags to provide a plurality of backscatter signals, estimating a signal parameter of the backscatter signals of the plurality of backscatter signals to provide a plurality of derived signal parameters, and localizing the item in accordance with the plurality of derived signal parameters. The backscatter signals are read by a tag reader having a single antenna and the item is localized in accordance with an antenna array technique performed upon the plurality of derived signal parameters. The backscatter signals are read with an antenna array to provide a further plurality of derived signal parameters for each tag of the plurality of tags, and the item is localized in accordance with the further pluralities of derived signal parameters.

摘要翻译： 一种用于标签通信系统的定位方法包括将具有多个标签的超标与物品相关联，从多个标签的标签中读取反向散射信号以提供多个后向散射信号，估计反向散射信号的信号参数 以提供多个导出的信号参数，以及根据多个导出的信号参数来定位该项目。 后向散射信号由具有单个天线的标签读取器读取，并且该项目根据对多个导出的信号参数执行的天线阵列技术进行定位。 用天线阵列读取反向散射信号，以便为多个标签中的每个标签提供另外多个导出的信号参数，并且根据进一步的多个导出信号参数来定位该物品。

公开(公告)号：US07652577B1

公开(公告)日：2010-01-26

申请号：US11702980

申请日：2007-02-05

申请人： Upamanyu Madhow ,  Ben J. Wild ,  Kannan Ramchandran

发明人： Upamanyu Madhow ,  Ben J. Wild ,  Kannan Ramchandran

IPC分类号： G08B13/14

CPC分类号： G06K7/10346

摘要： Systems and methods for beamforming in radio frequency identification (RFID) applications are disclosed. A beamforming system uses a distributed architecture and techniques for antenna beamforming using a feedback control loop to direct radio frequency (RF) energy onto a specific region, referred to as an interrogation zone, which includes a calibration node where one or more RFID tags may be located. The distributed architecture of the beamforming system is resistant to fading and shadowing effects, providing accurate RFID reader operation even in environments with multi-path reflections or environmental changes, such as people moving around or changes in the location of equipment.

摘要翻译： 公开了用于射频识别（RFID）应用中的波束成形的系统和方法。 波束成形系统使用分布式架构和技术用于天线波束成形，使用反馈控制回路将射频（RF）能量引导到称为询问区的特定区域，该特定区域包括校准节点，其中一个或多个RFID标签可以是 位于。 波束成形系统的分布式架构能够抵抗衰落和阴影效应，即使在具有多路径反射或环境变化的环境（例如人员移动或设备位置变化）的环境中也能提供精确的RFID读取器操作。

公开(公告)号：US20090212921A1

公开(公告)日：2009-08-27

申请号：US12072423

申请日：2008-02-25

申请人： Ben J. Wild ,  Artem Tkachenko ,  Kannan Ramchandran ,  Upamanyu Madhow

发明人： Ben J. Wild ,  Artem Tkachenko ,  Kannan Ramchandran ,  Upamanyu Madhow

IPC分类号： H04Q5/22 ,  G01S13/00

CPC分类号： G08C21/00 ,  G01S5/02 ,  G01S5/0252 ,  G01S11/02 ,  G01S13/756 ,  G01S13/876

摘要： Methods and systems for localizing an asset using the modulated backscatter from an asset tag and one or more marker tags are described. The system includes the reader, a location module and one or more marker tags. The location estimates for the asset tag are based partially on a prior knowledge of the location of each of the one or more marker tags. The location for each marker tag may be stored in a database. The location module determines a location estimate for the asset tag using the estimated parameters of the modulated backscatter signals received from one or more marker tags and from the asset tag. Using the known locations of the marker tags, a location estimate of the asset tag can be determined. The location estimate may be a relative location, an absolute location, and/or may be a zone including the marker tags. A mobile reader using the marker tags can localize asset tags throughout a large area and may, for example, take an inventory of assets throughout the large area.

摘要翻译： 描述了使用来自资产标签和一个或多个标记标签的调制反向散射来定位资产的方法和系统。 系统包括阅读器，位置模块和一个或多个标记标签。 资产标签的位置估计部分地基于对一个或多个标记标签中的每一个的位置的先验知识。 每个标记标签的位置可以存储在数据库中。 位置模块使用从一个或多个标记标签和资产标签接收的调制后向散射信号的估计参数来确定资产标签的位置估计。 使用标记标签的已知位置，可以确定资产标签的位置估计。 位置估计可以是相对位置，绝对位置，和/或可以是包括标记标签的区域。 使用标记标签的移动阅读器可以在大范围内对资产标签进行本地化，并且可以例如在整个大区域中进行资产盘点。

公开(公告)号：US07453855B1

公开(公告)日：2008-11-18

申请号：US11164868

申请日：2005-12-08

申请人： Upamanyu Madhow

发明人： Upamanyu Madhow

IPC分类号： H04B7/216

CPC分类号： H04B1/7103 ,  H04B1/709 ,  H04B1/71072

摘要： The present invention considers a direct sequence spread spectrum system wherein every user employs the same spreading code. In a preferred embodiment, received signal is correlated with the training signal. Peaks of correlator output are used to identify the delays corresponding to the significant multipath components. The delays that are within a predetermined number of chips of each other are associated with a hypothesized user. In an alternate embodiment, a user separation technique is used which is based on the observation that after the training period, different users send uncorrelated data. In another alternate embodiment, linear minimum mean squared error (LMMSE) based correlators locked to individual users are employed. These correlators only provide multipath components of their corresponding users as output.

摘要翻译： 本发明考虑了一种直接序列扩频系统，其中每个用户使用相同的扩展码。 在优选实施例中，接收信号与训练信号相关。 相关器输出的峰值用于识别对应于显着多径分量的延迟。 在预定数量的芯片之间的延迟与假设的用户相关联。 在替代实施例中，使用用户分离技术，其基于观察结果，在训练周期之后，不同的用户发送不相关的数据。 在另一个实施例中，采用了锁定到个人用户的基于线性最小均方误差（LMMSE）的相关器。 这些相关器仅提供其相应用户的多径分量作为输出。

公开(公告)号：US07099273B2

公开(公告)日：2006-08-29

申请号：US10061574

申请日：2002-01-29

申请人： Sungwon Ha ,  Sung-wook Han ,  Tae-eun Kim ,  Vaduvur Bharghavan ,  Upamanyu Madhow ,  Kannan Ramchandran

发明人： Sungwon Ha ,  Sung-wook Han ,  Tae-eun Kim ,  Vaduvur Bharghavan ,  Upamanyu Madhow ,  Kannan Ramchandran

IPC分类号： H04J1/16 ,  H04J3/14

CPC分类号： H04L1/0018 ,  H04L1/0002 ,  H04L1/1809 ,  H04L1/1874 ,  H04L1/188 ,  H04L1/1887 ,  H04L29/06 ,  H04L47/10 ,  H04L47/193 ,  H04L47/20 ,  H04L47/28 ,  H04L47/283 ,  H04L47/37 ,  H04L69/16 ,  H04L69/161 ,  H04L69/162 ,  H04L69/163 ,  Y02D50/10

摘要： Improved data transport and management within a network communication system may be achieved by utilizing a transmit timer incorporated within the sender device and exploiting host-level statistics for a plurality of connections between a sender and receiver. The period of the transmit timer may be periodically adjusted based on a ratio of the smoothed round-trip time and the smoothed congestion window, thereby reducing or eliminating bursty data transmission commonly associated with conventional TCP architectures. For applications having a plurality of connections between a sender and a receiver that share a common channel, such as web applications, the congestion window and smoothed round trip time estimates for all active connections may be used to initialize new connections and allocate bandwidth among existing connections. This aspect of the present invention may reduce the destructive interference that may occur as different connections compete with one another to maximize the bandwidth of each connection without regard to other connections serving the same application. Error recovery may also be improved by incorporating a short timer and a long timer that are configured to reduce the size of the congestion window and the corresponding transmission rate in response to a second packet loss with a predefined time period in order to increase resilience to random packet loss.

公开(公告)号：US06426973B1

公开(公告)日：2002-07-30

申请号：US09301912

申请日：1999-04-29

申请人： Upamanyu Madhow ,  Liping Julia Zhu ,  Luis Galup

发明人： Upamanyu Madhow ,  Liping Julia Zhu ,  Luis Galup

IPC分类号： H03H730

CPC分类号： H04B1/71055 ,  H04B1/7115 ,  H04B7/0854 ,  H04L2025/03605

摘要： This invention reformulates the MMSE criterion to apply to systems in which the desired data to be tracked is the ratio of the data appearing in successive observation intervals. The resulting differential MMSE criterion leads to a number of novel algorithms for adaptive implementation of the MMSE receiver. Applications include equalization for single user systems, and multiuser detection, or interference suppression, for direct sequence CDMA with short spreading sequences (i.e., the period of the spreading sequence equals the symbol interval). The invention also provides blind (i.e., without the requirement of a training symbol sequence for the user of interest) equalization and beamforming (using a receive antenna array) for direct sequence CDMA systems with long spreading sequences (i.e., systems in which the spreading sequences are aperiodic, or have period much larger than the symbol interval). The invention enables recovery of the desired symbol sequence up to an unknown phase. The invention is therefore well suited to the demodulation of differentially modulated data, in which information is encoded in the phase differences of successive transmitted symbols. Assuming that the channel amplitude and phase is approximately constant over two successive symbol intervals, the demodulator can use the differences in phases of two successive received symbols to recover differentially encoded data. The invention may also be used in conjunction with a separate phase recovery method to demodulate data without differential modulation.

摘要翻译： 本发明重新制定了MMSE准则，以适用于要跟踪的期望数据是在连续观察间隔中出现的数据的比率的系统。 得到的差分MMSE标准导致许多用于MMSE接收机的自适应实现的新颖算法。 应用包括用于单用户系统的均衡，以及用于具有短扩展序列的直接序列CDMA（即，扩展序列的周期等于符号间隔）的多用户检测或干扰抑制。 本发明还提供对于具有长扩展序列的直接序列CDMA系统（即，其中扩展序列的系统），盲目（即，不需要感兴趣的用户的训练符号序列）均衡和波束成形（使用接收天线阵列） 是非周期性的，或具有比符号间隔大得多的周期）。 本发明使得可以将期望的符号序列恢复到未知相位。 因此，本发明非常适合于差分调制数据的解调，其中信息被编码在连续传输符号的相位差中。 假设信道幅度和相位在两个连续符号间隔上近似恒定，则解调器可以使用两个连续接收符号的相位差来恢复差分编码数据。 本发明还可以与单独的相位恢复方法一起使用以在不进行差分调制的情况下解调数据。