Scattered Pilot Pattern And Channel Estimation Method For MIMO-OFDM Systems
    21.
    发明申请
    Scattered Pilot Pattern And Channel Estimation Method For MIMO-OFDM Systems 有权
    用于MIMO-OFDM系统的分散导频模式和信道估计方法

    公开(公告)号:US20120307930A1

    公开(公告)日:2012-12-06

    申请号:US13586660

    申请日:2012-08-15

    IPC分类号: H04B7/04

    摘要: A method and apparatus are provided for reducing the number of pilot symbols within a MIMO-OFDM communication system, and for improving channel estimation within such a system. For each transmitting antenna in an OFDM transmitter, pilot symbols are encoded so as to be unique to the transmitting antenna. The encoded pilot symbols are then inserted into an OFDM frame to form a diamond lattice, the diamond lattices for the different transmitting antennae using the same frequencies but being offset from each other by a single symbol in the time domain. At the OFDM receiver, a channel response is estimated for a symbol central to each diamond of the diamond lattice using a two-dimensional interpolation. The estimated channel responses are smoothed in the frequency domain. The channel responses of remaining symbols are then estimated by interpolation in the frequency domain.

    摘要翻译: 提供了一种用于减少MIMO-OFDM通信系统内的导频符号的数量并改善这种系统内的信道估计的方法和装置。 对于OFDM发射机中的每个发射天线,导频符号被编码为对于发射天线是唯一的。 然后将编码的导频符号插入到OFDM帧中以形成菱形晶格,使用相同频率的不同发射天线的菱形晶格,但是在时域中通过单个符号彼此偏移。 在OFDM接收机处,使用二维插值来估计针对钻石晶格的每个菱形的中心的符号的信道响应。 估计的信道响应在频域中被平滑化。 然后通过在频域中的内插来估计剩余符号的信道响应。

    Multi-user MIMO systems and methods
    22.
    发明授权
    Multi-user MIMO systems and methods 有权
    多用户MIMO系统和方法

    公开(公告)号:US08284852B2

    公开(公告)日:2012-10-09

    申请号:US13251394

    申请日:2011-10-03

    IPC分类号: H04L27/28

    摘要: A method and system are provided for scheduling data transmission in a Multiple-Input Multiple-Output (MIMO) system. The MIMO system may comprise at least one MIMO transmitter and at least one MIMO receiver. Feedback from one or more receivers may be used by a transmitter to improve quality, capacity, and scheduling in MIMO communication systems. The method may include generating or receiving information pertaining to a MIMO channel metric and information pertaining to a Channel Quality Indicator (CQI) in respect of a transmitted signal; and sending a next transmission to a receiver using a MIMO mode selected in accordance with the information pertaining to the MIMO channel metric, and an adaptive coding and modulation selected in accordance with the information pertaining to the CQI.

    摘要翻译: 提供了一种用于在多输入多输出(MIMO)系统中调度数据传输的方法和系统。 MIMO系统可以包括至少一个MIMO发射机和至少一个MIMO接收机。 来自一个或多个接收机的反馈可以被发射机用于改善MIMO通信系统中的质量,容量和调度。 该方法可以包括产生或接收关于MIMO信道度量的信息和关于发射信号的与信道质量指示符(CQI)有关的信息; 以及使用根据与所述MIMO信道度量有关的信息选择的MIMO模式以及根据与所述CQI有关的信息选择的自适应编码和调制,向接收机发送下一个传输。

    Soft handoff in OFDMA system
    24.
    发明授权
    Soft handoff in OFDMA system 有权
    OFDMA系统中的软切换

    公开(公告)号:US08165094B2

    公开(公告)日:2012-04-24

    申请号:US13221601

    申请日:2011-08-30

    IPC分类号: H04W36/00

    摘要: Soft handoff in an OFDMA system is disclosed. If the pilot signal strength for a base station exceeds the defined threshold, the base station is added to an active set list. Subcarriers in a plurality of orthogonal frequency division multiplexing (OFDM) symbols are divided and allocated into subchannels. The OFDM symbols are divided and multiplexed. A soft handoff zone with a first dimension of the subchannels and a second dimension of the divided and multiplexed OFDM symbols is defined. The soft handoff zone has subcarriers with a subchannel definition, for example, an identical permutation.

    摘要翻译: 披露了OFDMA系统中的软切换。 如果基站的导频信号强度超过定义的阈值,则将基站添加到活动集列表中。 多个正交频分复用(OFDM)符号中的子载波被划分并分配给子信道。 OFDM符号被分割和多路复用。 定义了具有子信道的第一维度和分割和多路复用的OFDM符号的第二维度的软切换区域。 软切换区具有子信道定义的子载波,例如相同的置换。

    Communication signal decoding and soft demapping methods and systems
    25.
    发明授权
    Communication signal decoding and soft demapping methods and systems 有权
    通信信号解码和软解映射方法和系统

    公开(公告)号:US08116410B1

    公开(公告)日:2012-02-14

    申请号:US10913403

    申请日:2004-08-09

    IPC分类号: H04L27/06

    摘要: Symbol detection and soft dempapping methods and systems are provided. Individual subset symbol detection according to an embodiment of the invention involves identifying a search subset of a transmission symbol set for a transmission symbol. For each other transmission symbol in communication signals, multiple search subsets of the transmission symbol set are identified. The multiple search subsets include respective search subsets based on each transmission symbol in either the search subset for the first identified one of the transmission symbols or each of the multiple search subsets identified for a different one of the other transmission symbols. Symbol detection errors may be detected by identifying competing symbols and computing competing distances. Soft demapping may be provided by calculating soft decision results based on detected symbols and weighting the soft decision result.

    摘要翻译: 提供符号检测和软解压方法和系统。 根据本发明的实施例的个体子集符号检测涉及识别用于传输符号的传输符号组的搜索子集。 对于通信信号中的每个其他传输符号,识别传输符号集合的多个搜索子集。 多个搜索子集包括基于针对第一被识别的一个传输符号的搜索子集中的每个传输符号或为其它传输符号中的不同一个标识的多个搜索子集中的每一个的每个传输符号。 可以通过识别竞争符号和计算竞争距离来检测符号检测错误。 可以通过基于检测到的符号计算软判定结果并对软决策结果加权来提供软解映射。

    Methods and systems for OFDM using code division multiplexing
    26.
    发明授权
    Methods and systems for OFDM using code division multiplexing 有权
    使用码分复用的OFDM方法和系统

    公开(公告)号:US08111763B2

    公开(公告)日:2012-02-07

    申请号:US11910091

    申请日:2006-03-30

    IPC分类号: H04L27/28

    摘要: In some embodiments of the invention, OFDM symbols are transmitted as a plurality of clusters. A cluster includes a plurality of OFDM sub-carriers in frequency, over a plurality of OFDM symbol durations in time. Each cluster includes data as well as pilot information as a reference signal for channel estimation. In some embodiments, a plurality of clusters collectively occupy the available sub-carrier set in the frequency domain that is used for transmission. In some embodiments of the invention data and/or pilots are spread within each cluster using code division multiplexing (CDM). In some embodiments pilots and data are separated by distributing data on a particular number of the plurality of OFDM symbol durations and pilots on a remainder of the OFDM symbol durations. CDM spreading can be performed in time and/or frequency directions.

    摘要翻译: 在本发明的一些实施例中,OFDM符号作为多个簇发送。 在多个OFDM符号持续时间内,群集包括频率上的多个OFDM子载波。 每个簇包括数据以及作为信道估计的参考信号的导频信息。 在一些实施例中,多个集群共同地占用用于传输的频域中的可用子载波集合。 在本发明的一些实施例中,使用码分多路复用(CDM)在每个簇内扩展数据和/或导频。 在一些实施例中,通过在OFDM码元持续时间的其余部分上分配关于多个OFDM符号持续时间的特定数目和导频上的数据来分离导频和数据。 可以在时间和/或频率方向上执行CDM扩展。