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    Synchronization in a broadcast OFDM system using time division multiplexed pilots
    3.
    发明申请
    Synchronization in a broadcast OFDM system using time division multiplexed pilots 审中-公开
    使用时分复用导频的广播OFDM系统中的同步

    公开(公告)号：US20050063298A1

    公开(公告)日：2005-03-24

    申请号：US10931324

    申请日：2004-08-31

    申请人： Fuyun Ling ,  Alok Gupta ,  Raghuraman Krishnamoorthi ,  Ramaswamy Murali ,  Rajiv Vijayan ,  Bojan Vrcelj

    发明人： Fuyun Ling ,  Alok Gupta ,  Raghuraman Krishnamoorthi ,  Ramaswamy Murali ,  Rajiv Vijayan ,  Bojan Vrcelj

    IPC分类号： H04B3/10 ,  H04J20060101 ,  H04J1/16 ,  H04J11/00

    CPC分类号： H04L27/2657 ,  H04L5/005 ,  H04L25/022 ,  H04L27/2613 ,  H04L27/2662 ,  H04L27/2665 ,  H04L2027/003

    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，随后在每帧中的第二组子带上接收第二TDM导频。 每个组中的子带从N个总子带中选出，使得（1）第一TDM导频的OFDM符号包含长度为L1的至少S1个相同的导频1序列，以及（2）第二TDM导频的OFDM符号包含 至少S2个长度为L2的导频-2序列，其中L2> L1，S1.L1 = N，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）并且进一步处理第二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 从第二TDM导频）。

    POWER SAVINGS IN HIERARCHICALLY CODED MODULATION
    6.
    发明申请
    POWER SAVINGS IN HIERARCHICALLY CODED MODULATION 有权
    节能调节中的省电

    公开(公告)号：US20100220816A1

    公开(公告)日：2010-09-02

    申请号：US12777540

    申请日：2010-05-11

    申请人： Gordon Kent Walker ,  Rajiv Vijayan ,  Seong Taek Chung ,  Murali Ramaswamy Chari ,  Fuyun Ling

    发明人： Gordon Kent Walker ,  Rajiv Vijayan ,  Seong Taek Chung ,  Murali Ramaswamy Chari ,  Fuyun Ling

    IPC分类号： H04L27/00

    CPC分类号： H04L27/3488 ,  H04W52/0245 ,  Y02D70/00

    摘要： A wireless communication apparatus in a hierarchically coded modulation system can use error control mechanisms generated during decoding of base layer information to predict a probability of successful demodulation of enhancement layer information. Performance in the demodulation of the base layer correlates to performance in the demodulation of the enhancement layer. The receiver can determine whether to attempt demodulation of temporally correlated enhancement layer data based in part on the predicted probability of success. If the receiver determines not to demodulate the enhancement layer, the receiver can power down the enhancement layer demodulator, or otherwise minimize the power expended in the enhancement layer demodulator.

    摘要翻译： 分级编码调制系统中的无线通信装置可以使用在解码基层信息期间产生的误差控制机制来预测增强层信息的成功解调的概率。 基层解调性能与增强层解调性能有关。 接收机可以部分地基于预测的成功概率来确定是否尝试对时间相关的增强层数据的解调。 如果接收机确定不解调增强层，则接收机可以将增强层解调器断电，或以其他方式最小化增强层解调器中消耗的功率。

    Wide area and local network ID transmission for communication systems
    9.
    发明申请
    Wide area and local network ID transmission for communication systems 有权
    通信系统的广域和本地网络ID传输

    公开(公告)号：US20060133388A1

    公开(公告)日：2006-06-22

    申请号：US11021310

    申请日：2004-12-22

    申请人： Michael Wang ,  Bojan Vrcelj ,  Krishna Mukkavilli ,  Raghuraman Krishnamoorthi ,  Rajiv Vijayan

    发明人： Michael Wang ,  Bojan Vrcelj ,  Krishna Mukkavilli ,  Raghuraman Krishnamoorthi ,  Rajiv Vijayan

    IPC分类号： H04L12/56

    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.

    摘要翻译： 这些实施例利用OFDM符号来传送网络ID。 ID被编码成使用网络ID作为种子的符号，以对通过利用符号进行发送的各个导频进行加扰。 导频可以被构造成单个OFDM符号和/或多个OFDM符号。 用于发送网络ID的单个符号结构与网络ID比特数无关，并且使频偏和多普勒效应最小化。 多符号结构允许以牺牲传输附加符号为代价采用更粗糙的定时精度。 几个实施例采用搜索功能来从发送的符号和选择功能中找到可能的网络ID候选，以从网络ID候选列表中找到最佳候选。