Wireless Feedback System and Method
    115.
    发明申请
    Wireless Feedback System and Method 有权
    无线反馈系统和方法

    公开(公告)号:US20160294458A1

    公开(公告)日:2016-10-06

    申请号:US15175246

    申请日:2016-06-07

    Applicant: Apple Inc.

    Abstract: A codebook C is provided in a MIMO transmitter as well as a MIMO receiver. The codebook C will include M codewords ci, where i is a unique codeword index for each codeword ci. Each codeword defines weighting factors to apply to the MIMO signals, and may correspond to channel matrices or vectors to apply to the MIMO signals prior to transmission from the respective antennas of the MIMO transmitter. The present invention creates codeword subsets Si for each codeword ci of the codebook C. Each codeword subset Si defines L codewords cj, which are selected from all the codewords ci in the codebook C. The codewords cj in a codeword subset Si are the L codewords in the entire codebook that best correlate with the corresponding codeword ci.

    Abstract translation: 码本C被提供在MIMO发射机以及MIMO接收机中。 码本C将包括M个码字ci,其中i是每个码字ci的唯一码字索引。 每个码字定义了应用于MIMO信号的加权因子,并且可以对应于在从MIMO发射机的各个天线发送之前应用于MIMO信号的信道矩阵或向量。 本发明为码本C的每个码字ci创建码字子集Si。每个码字子集Si定义了从码本C中的所有码字ci中选择的L个码字cj。码字子集Si中的码字cj是L个码字 在整个码本中与相应的码字ci最相关。

    Pilot symbol patterns for transmit antennas
    116.
    发明授权
    Pilot symbol patterns for transmit antennas 有权
    用于发射天线的导频符号模式

    公开(公告)号:US09432232B2

    公开(公告)日:2016-08-30

    申请号:US15046934

    申请日:2016-02-18

    Applicant: Apple Inc.

    Abstract: A method and apparatus for improving channel estimation within an OFDM communication system. Channel estimation in OFDM is usually performed with the aid of pilot symbols. The pilot symbols are typically spaced in time and frequency. The set of frequencies and times at which pilot symbols are inserted is referred to as a pilot pattern. In some cases, the pilot pattern is a diagonal-shaped lattice, either regular or irregular. The method first interpolates in the direction of larger coherence (time or frequency). Using these measurements, the density of pilot symbols in the direction of faster change will be increased thereby improving channel estimation without increasing overhead. As such, the results of the first interpolating step can then be used to assist the interpolation in the dimension of smaller coherence (time or frequency).

    Abstract translation: 一种用于改善OFDM通信系统内的信道估计的方法和装置。 OFDM中的信道估计通常借助于导频符号来执行。 导频符号通常在时间和频率上间隔开。 将导频符号插入的频率和时间的集合称为导频模式。 在一些情况下,导频图案是对角线形格子,规则的或不规则的。 该方法首先在较大相干性(时间或频率)的方向内插。 使用这些测量,导频符号在更快变化方向上的密度将增加,从而改善信道估计而不增加开销。 因此,第一内插步骤的结果然后可以用于辅助尺寸较小的相干性(时间或频率)的内插。

    Methods and Systems for OFDM using Code Division Multiplexing
    120.
    发明申请
    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:US20150085821A1

    公开(公告)日:2015-03-26

    申请号:US14557319

    申请日:2014-12-01

    Applicant: Apple Inc.

    Abstract: 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.

    Abstract translation: 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。

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