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    FFT collection window positioning using OFDM symbol time tracking information
    1.
    发明授权
    FFT collection window positioning using OFDM symbol time tracking information 有权
    使用OFDM符号时间跟踪信息收集FFT窗口位置

    公开(公告)号：EP1869857B1

    公开(公告)日：2010-03-03

    申请号：EP06737928.9

    申请日：2006-03-09

    申请人： QUALCOMM Incorporated

    发明人： VRCELJ, Bojan ,  MANTRAVADI, Ashok ,  LING, Fuyun ,  VIJAYAN, Rajiv ,  WANG, Michael, Mao

    IPC分类号： H04L27/26

    CPC分类号： H04L27/2662 ,  H04L5/0007 ,  H04L5/0048 ,  H04L25/0216 ,  H04L25/022 ,  H04L25/0228 ,  H04L27/261 ,  H04L27/265 ,  H04L27/2665 ,  H04L27/2679

    摘要： A method for positioninga collection window for a Fourier transform function is disclosed. A first orthogonal frequency division multiplexing (OFDM) symbol and a second OFDM symbol are received. The first OFDM symbol comprises a plurality of frequency division multiplexed (FDM) symbols. The first OFDM symbol is characterized by at least two of the following: a delay spread, a first arriving path (FAP), or a last arriving path (LAP). A channel location is estimated from a channel impulse response. A point relative to the channel location is selected. A beginning of the collection window is positionedfor the second OFDM symbol at the selected point. Alternatively, apoint is selectedat a first location relative to the channel location using a first algorithm if a delay spread is less than a predetermined length. The selected point is chosen at a second location relative to the channel location using a second algorithm if the delay spread is greater than the predetermined length.

    ANTENNA ARRAY CALIBRATION FOR WIRELESS COMMUNICATION SYSTEMS
    2.
    发明公开
    ANTENNA ARRAY CALIBRATION FOR WIRELESS COMMUNICATION SYSTEMS 有权
    KALIBRIERUNG EINER GRUPPENENTENNEFÜRDRAHTLOSE KOMMUNIKATIONSSYSTEME

    公开(公告)号：EP1946407A2

    公开(公告)日：2008-07-23

    申请号：EP06846215.9

    申请日：2006-11-02

    申请人： Qualcomm Incorporated

    发明人： NAGUIB, Ayman Fawzy ,  GOROKHOV, Alexei ,  VIJAYAN, Rajiv

    IPC分类号： H01Q3/26

    CPC分类号： H01Q3/267 ,  H04B17/12 ,  H04B17/21

    摘要： Calibration for a transmit chain of a device transmitting information to multiple devices over wireless links includes selecting from between two or more calibration determination techniques. In certain aspects the techniques include phase only calibration and phase and amplitude calibration.

    摘要翻译： 通过无线链路向多个设备发送信息的设备的发射链的校准包括从两个或更多个校准确定技术之间进行选择。 在某些方面，这些技术包括仅相位校准和相位和幅度校准。

    METHOD AND APPARATUS FOR ADAPTIVE SET MANAGEMENT IN A COMMUNICATION SYSTEM
    5.
    发明公开
    METHOD AND APPARATUS FOR ADAPTIVE SET MANAGEMENT IN A COMMUNICATION SYSTEM 有权
    METHOD AND APPARATUS FOR基站的一个功能强大的MANAGING集的通信系统中的调整

    公开(公告)号：EP1400148A1

    公开(公告)日：2004-03-24

    申请号：EP02756322.0

    申请日：2002-06-25

    申请人： QUALCOMM INCORPORATED

    发明人： ATTAR, Rashid, Ahmed ,  VIJAYAN, Rajiv ,  SINDHUSHAYANA, Nagabhushana, T.

    IPC分类号： H04Q7/38

    CPC分类号： H04W36/06 ,  H04L1/20 ,  H04W36/18 ,  H04W52/24 ,  H04W52/26

    摘要： Methods and apparatus for an adaptive set management in a communication system are disclosed. Certain levels of an imbalance between a forward link and a reverse link are always present in a communication system. Although severe levels of an imbalance cause a detrimental effect on quality of communication and throughput, the imbalance is an issue only if it degrades throughput by one rate on the forward link. Consequently, an adaptive set management evaluates an imbalance among sectors in a subscriber station's list in accordance with the quality metric of the forward link and the reverse link, and removes from the subscriber station's list only a sector that causes severe imbalance. Although retaining a sector in the subscriber station's list may improve throughput, it may negatively affect other functions of the communication system, e.g., power control. Therefore, a method of power control is modified if a level of imbalance affecting the power control is detected.

    FREQUENCY TRACKING FOR COMMUNICATION SIGNALS USING M-ARY ORTHOGONAL WALSH MODULATION
    6.
    发明公开
    FREQUENCY TRACKING FOR COMMUNICATION SIGNALS USING M-ARY ORTHOGONAL WALSH MODULATION 失效
    率的影响对于新闻传输信号使用M档沃尔什正交调制

    公开(公告)号：EP0829146A1

    公开(公告)日：1998-03-18

    申请号：EP97918684.0

    申请日：1997-03-26

    申请人： QUALCOMM INCORPORATED

    发明人： AGRAWAL, Avneesh ,  VIJAYAN, Rajiv

    IPC分类号： H03L7 ,  H04B1 ,  H04L7

    CPC分类号： H04B1/7085 ,  H04B1/709

    摘要： A frequency tracking loop for a communication system using orthogonal Walsh modulation is provided. The frequency tracking loop includes a correlator (120) such as a fast Hadamard transformation device, and a discriminator (130). The correlator (120) produces a correlation vector (122) representing the result of correlating the input signal with each of a set of Walsh functions, with corresponding index values. The discriminator (130) produces a frequency error signal (ê) based on the correlator (120) output with the highest energy level and other correlator outputs whose indices are related to the index of highest energy correlator output by powers of two. The frequency error signal (ê) is generated by producing a cross product between the highest energy output and one or more of the other related correlator outputs. In further aspects, a filter (140) can be used to further shape the resulting error signal (ê) and form a frequency offset estimate signal (f).

    SYNCHRONIZATION IN A BROADCAST OFDM SYSTEM USING TIME DIVISION MULTIPLEXED PILOTS
    7.
    发明公开
    SYNCHRONIZATION IN A BROADCAST OFDM SYSTEM USING TIME DIVISION MULTIPLEXED PILOTS 审中-公开
    利用时分复用导频在广播OFDM系统中同步

    公开(公告)号：EP2210384A2

    公开(公告)日：2010-07-28

    申请号：EP08844481.5

    申请日：2008-10-31

    申请人： QUALCOMM Incorporated

    发明人： LING, Fuyun ,  GUPTA, Alok Kumar ,  KRISHNAMOORTHI, Raghuraman ,  CHARI, Murali Ramaswamy ,  VIJAYAN, Rajiv ,  VRCELJ, Bojan

    IPC分类号： H04L27/26

    CPC分类号： H04L27/2675 ,  H04L5/0007 ,  H04L5/0051 ,  H04L5/0064 ,  H04L7/042 ,  H04L25/0212 ,  H04L25/0216 ,  H04L25/0224 ,  H04L25/0226 ,  H04L27/2613 ,  H04L27/2656 ,  H04L27/2657 ,  H04L27/2662

    摘要： In an OFDM system, a transmitter broadcasts a first TDM pilot on a first set of subbands followed by a second TDM pilot on a second set of subbands in each frame. The subbands in each set are selected from among N total subbands such that (1) an OFDM symbol for the first TDM pilot contains at least S1 identical pilot-1 sequences of length L1 and (2) an OFDM symbol for the second TDM pilot contains at least S2 identical pilot-2 sequences of length L2, where L2 > L1, S1 • L1 = N, and S2 • L2 = N. The transmitter may also broadcast an FDM pilot. A receiver processes the first TDM pilot to obtain frame timing (e.g., by performing correlation between different pilot-1 sequences) and further processes the second TDM pilot to obtain symbol timing (e.g., by detecting for the start of a channel impulse response estimate derived from the second TDM pilot).

    摘要翻译： 在OFDM系统中，发射机在第一组子带上广播第一TDM导频，然后在每帧中的第二组子带上广播第二TDM导频。 （1）用于第一TDM导频的OFDM符号包含至少S1个相同的长度为L1的导频-1序列，以及（2）用于第二TDM导频的OFDM符号包含 至少具有长度为L2的S2个相同的导频-2序列，其中L2> L1，S1·L1 = N，并且S2·L2 = N。发射机还可以广播FDM导频。 接收机处理第一TDM导频以获得帧定时（例如，通过执行不同导频-1序列之间的相关）并进一步处理第二TDM导频以获得符号定时（例如，通过检测导出的信道脉冲响应估计的开始 来自第二个TDM试点）。

    APPARATUS AND METHOD FOR DETERMINING SLEEP CLOCK TIMING
    8.
    发明授权
    APPARATUS AND METHOD FOR DETERMINING SLEEP CLOCK TIMING 有权
    装置和方法用于确定睡眠冲程正

    公开(公告)号：EP1869780B1

    公开(公告)日：2010-04-21

    申请号：EP06737617.8

    申请日：2006-03-08

    申请人： QUALCOMM INCORPORATED

    发明人： WANG, Michael Mao ,  LING, Fuyun ,  VIJAYAN, Rajiv

    IPC分类号： H04B1/16

    CPC分类号： H04W52/029 ,  Y02D70/00

    摘要： Apparatus and methods for estimating the frequency of a sleep or slow clock by selectively utilizing an estimated sleep clock frequency and an estimated change in the sleep clock frequency. The disclosed apparatus includes a sleep clock frequency estimator to output a fast clock derived sleep clock frequency estimate and a sleep clock change frequency estimator to output an estimate of a change in frequency of the sleep clock. The apparatus further includes a combiner that weights at least one of the fast clock derived sleep clock frequency estimate to obtain a weighted sleep clock frequency estimate and the estimate of the change in frequency of the sleep clock to obtain a weighted estimate of the change in frequency of the sleep clock. The combiner also determines a new estimate of the sleep clock frequency using at least one of the weighted sleep clock frequency estimate and the weighted estimate of the change in frequency of the sleep clock. Complementary methods are also disclosed.

    FREQUENCY ERROR ESTIMATION AND FRAME SYNCHRONIZATION IN AN OFDM SYSTEM
    9.
    发明授权
    FREQUENCY ERROR ESTIMATION AND FRAME SYNCHRONIZATION IN AN OFDM SYSTEM 有权
    频率误差估计和帧同步在OFDM系统

    公开(公告)号：EP1706976B1

    公开(公告)日：2008-12-03

    申请号：EP05705174.0

    申请日：2005-01-07

    申请人： Qualcomm, Incorporated

    发明人： VIJAYAN, Rajiv ,  GUPTA, Alok Kumar ,  KRISHNAMOORTHI, Raghuraman

    IPC分类号： H04L27/26

    CPC分类号： H04L27/2656 ,  H04L27/2657 ,  H04L27/2675

    摘要： Frequency error estimation and frame synchronization are performed at a receiver in an OFDM system based on a metric that is indicative of detected pilot power. The metric may be defined based on cross-correlation between two received symbols obtained in two OFDM symbol periods. For frequency error estimation, a metric value is computed for each of multiple hypothesized frequency errors. The hypothesized frequency error for the metric value with the largest magnitude is provided as the estimated frequency error. For frame synchronization, a correlation value is obtained for each OFDM symbol period by correlating metric values obtained for NC (e.g., most recent) OFDM symbol periods with NC expected values. The expected values are computed in a manner consistent with the manner in which the metric values are computed. Peak detection is performed on the correlation values obtained for different OFDM symbol periods to determine frame synchronization.