PREAMBLES IN OFDMA SYSTEM
    171.
    发明申请
    PREAMBLES IN OFDMA SYSTEM 审中-公开
    OFDMA系统中的前缀

    公开(公告)号:US20170005852A1

    公开(公告)日:2017-01-05

    申请号:US15267396

    申请日:2016-09-16

    Applicant: APPLE INC.

    Abstract: The present invention provides a preamble that is inserted into an OFDMA frame and has a common sequence for all the base stations participating in a transmission. The subscriber station performs fine synchronization using the common sequence on the common preamble, and the resulting peaks will provide the locations of candidate base stations. The base station specific search is then performed in the vicinities of those peaks by using base station specific pseudo-noise sequences. With this two stage cell search, the searching window is drastically reduced. The preamble is matched to known values by a respective receiver to decode the signals and permit multiple signals to be transferred from the transmitter to the receiver. The preamble may comprise two parts, Preamble-1 and Preamble-2, which may be used in different systems, including multioutput, multi-input (MIMO) systems.

    Abstract translation: 本发明提供插入到OFDMA帧中并具有参与传输的所有基站的公共序列的前同步码。 用户站使用公共前导码上的公共序列执行精细同步,并且所得到的峰值将提供候选基站的位置。 然后通过使用基站专用伪噪声序列,在那些峰附近执行基站专用搜索。 通过这两个阶段的单元格搜索,搜索窗口大大减少。 前导码由相应的接收机与已知值匹配以对信号进行解码,并允许多个信号从发射机传送到接收机。 前导码可以包括两个部分,即前导码1和前导码2,其可以在不同的系统中使用,包括多输入多输入(MIMO)系统。

    Wireless Feedback System and Method
    172.
    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。

    Preambles in OFDMA system
    173.
    发明授权
    Preambles in OFDMA system 有权
    OFDMA系统中的前缀

    公开(公告)号:US09450801B2

    公开(公告)日:2016-09-20

    申请号:US13680209

    申请日:2012-11-19

    Applicant: Apple Inc.

    Abstract: The present invention provides a preamble that is inserted into an OFDMA frame and has a common sequence for all the base stations participating in a transmission. The subscriber station performs fine synchronization using the common sequence on the common preamble, and the resulting peaks will provide the locations of candidate base stations. The base station specific search is then performed in the vicinities of those peaks by using base station specific pseudo-noise sequences. With this two stage cell search, the searching window is drastically reduced. The preamble is matched to known values by a respective receiver to decode the signals and permit multiple signals to be transferred from the transmitter to the receiver. The preamble may comprise two parts, Preamble-I and Preamble-2, which may be used in different systems, including multioutput, multi-input (MIMO) systems.

    Abstract translation: 本发明提供插入到OFDMA帧中并具有参与传输的所有基站的公共序列的前同步码。 用户站使用公共前导码上的公共序列执行精细同步,并且所得到的峰值将提供候选基站的位置。 然后通过使用基站专用伪噪声序列,在那些峰附近执行基站专用搜索。 通过这两个阶段的单元格搜索,搜索窗口大大减少。 前导码由相应的接收机与已知值匹配以对信号进行解码,并允许多个信号从发射机传送到接收机。 前导码可以包括两个部分,即前导码1和前导码2,其可以在不同的系统中使用,包括多输入多输入(MIMO)系统。

    Pilot symbol patterns for transmit antennas
    174.
    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
    179.
    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。

    Method and system for combining OFDM and transformed OFDM
    180.
    发明授权
    Method and system for combining OFDM and transformed OFDM 有权
    用于组合OFDM和变换OFDM的方法和系统

    公开(公告)号:US08947994B2

    公开(公告)日:2015-02-03

    申请号:US14251627

    申请日:2014-04-13

    Applicant: Apple Inc.

    Abstract: Methods and systems are provided that enable an OFDM transmitter to be used for transmitting conventional OFDM or a form of transformed OFDM. A technique is provided for transforming a coded and modulated sequence of samples prior to an IFFT that enables the transformed sequence of samples to be transmitted using conventional OFDM or transformed OFDM. The selection of a transform function for transforming the coded and modulated sequence of samples may be based on optimizing the transform function for particular operating conditions between the transmitter and receiver. In some embodiments of the invention OFDM and time transformed OFDM are multiplexed in time and/or frequency in a transmission frame. In some embodiments of the invention a pilot pattern is provided in which the pilot are sent using OFDM and data is sent using OFDM and/or transformed OFDM.

    Abstract translation: 提供了使OFDM发射机能够用于传输常规OFDM或变换OFDM形式的方法和系统。 提供了一种用于在IFFT之前变换样本的编码和调制序列的技术,其使得能够使用常规OFDM或变换OFDM来发送变换的样本序列。 用于变换样本的编码和调制序列的变换函数的选择可以基于优化发射机和接收机之间的特定操作条件的变换函数。 在本发明的一些实施例中,OFDM和时变OFDM在传输帧中以时间和/或频率被复用。 在本发明的一些实施例中,提供了导频模式,其中使用OFDM发送导频,并且使用OFDM和/或经变换的OFDM发送数据。

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