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    FFT collection window positioning using OFDM symbol time tracking information
    2.
    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.

    METHODS AND APPARATUS FOR TIMING SYNCHRONIZATION BASED ON TRANSITIONAL PILOT SYMBOLS
    8.
    发明公开
    METHODS AND APPARATUS FOR TIMING SYNCHRONIZATION BASED ON TRANSITIONAL PILOT SYMBOLS 审中-公开
    方法和设备，它ÜBERGANGSPILOTSYSMBOLEN基于时间同步

    公开(公告)号：EP2127286A2

    公开(公告)日：2009-12-02

    申请号：EP08713550.5

    申请日：2008-01-04

    申请人： QUALCOMM Incorporated

    发明人： VRCELJ, Bojan ,  MUKKAVILLI, Krishna Kiran ,  MANTRAVADI, Ashok ,  KRISHNAMOORTHI, Raghuraman

    IPC分类号： H04L27/26

    CPC分类号： H04L27/2662 ,  H04L5/0048 ,  H04L7/08 ,  H04L25/0216 ,  H04L25/023 ,  H04L27/2613 ,  H04L27/2675 ,  H04L27/2695

    摘要： Methods and apparatus for timing synchronization based on transitional pilot symbols. In an aspect, a method is provided for time tracking synchronization in an OFDM system. The method includes receiving at least one TDM pilot symbol comprising a plurality of modulated sub-carriers that are configured to provide a channel estimate having a length that extends up to a duration of an FFT used for data transmission. The method also includes determining one or both of an instantaneous and averaged channel estimates from the plurality of modulated sub-carriers, and calculating a timing offset based on one or both of the channel estimates. An apparatus includes a receiver configured to receive the at least one TDM pilot symbol, a channel estimator configured to determine the instantaneous and averaged channel estimates, and a time synchronizer configured to calculate a timing offset based on the channel estimates.

    WIDE AREA AND LOCAL NETWORK ID TRANSMISSION FOR COMMUNICATION SYSTEMS
    9.
    发明公开
    WIDE AREA AND LOCAL NETWORK ID TRANSMISSION FOR COMMUNICATION SYSTEMS 审中-公开
    ID发送大型水面和地方网络通讯系统

    公开(公告)号：EP1836820A1

    公开(公告)日：2007-09-26

    申请号：EP05855376.9

    申请日：2005-12-21

    申请人： Qualcomm Incorporated

    发明人： WANG, Michael Mao ,  VRCELJ, Bojan ,  MUKKAVILLI, Krishna Kiran ,  KRISHNAMOORTHI, Raghuraman ,  VIJAYAN, Rajiv

    IPC分类号： H04L27/26

    CPC分类号： H04L5/0048 ,  H04L5/0007 ,  H04L5/0083 ,  H04L27/261

    摘要： The embodiments utilize OFDM symbols to communicate network IDs. The IDs are encoded into symbols utilizing the network IDs as seeds to scramble respective pilots that are then transmitted by utilizing the symbols. The pilots can be structured into a single OFDM symbol and/or multiple OFDM symbols. The single symbol structure for transmitting the network IDs is independent of the number of network ID bits and minimizes frequency offset and Doppler effects. The multiple symbol structure allows a much coarser timing accuracy to be employed at the expense of transmitting additional symbols. Several embodiments employ a search function to find possible network ID candidates from a transmitted symbol and a selection function to find an optimum candidate from a network ID candidate list.