Communication systems and methods
    63.
    发明授权
    Communication systems and methods 有权
    通信系统和方法

    公开(公告)号:US09450663B2

    公开(公告)日:2016-09-20

    申请号:US14746972

    申请日:2015-06-23

    Applicant: Apple Inc.

    Abstract: In accordance with embodiments, a communication system includes a first device and a second device in communication with the first device. The second device has at least a first pair and a second pair of antennas. The second device spreads a communication bit by a predetermined spreading factor and forms a first set of spatial block codes in frequency domain based on the spread communication bit. The first set of spatial block codes being consecutively transmitted on one of the first and second pairs of antennas.

    Abstract translation: 根据实施例,通信系统包括与第一设备通信的第一设备和第二设备。 第二装置具有至少第一对和第二对天线。 第二设备以预定的扩展因子扩展通信位,并且基于扩展通信位在频域中形成第一组空间块码。 第一组空间块码在第一和第二对天线之一上连续发射。

    Pilot scheme for a MIMO communication system
    66.
    发明授权
    Pilot scheme for a MIMO communication system 有权
    MIMO通信系统的导频方案

    公开(公告)号:US09008036B2

    公开(公告)日:2015-04-14

    申请号:US13721784

    申请日:2012-12-20

    Applicant: Apple Inc.

    Abstract: The present invention employs a pilot scheme for frequency division multiple access (FDM) communication systems, such as single carrier FDM communication systems. A given transmit time interval will include numerous traffic symbols and two or more short pilot symbols, which are spaced apart from one another by at least one traffic symbol and will have a Fourier transform length that is less than the Fourier transform length of any given traffic symbol. Multiple transmitters will generate pilot information and modulate the pilot information onto sub-carriers of the short pilot symbols in an orthogonal manner. Each transmitter may use different sub-carriers within the time and frequency domain, which is encompassed by the short pilot symbols within the transmit time interval. Alternatively, each transmitter may uniquely encode the pilot information using a unique code division multiplexed code and modulate the encoded pilot information onto common sub-carriers of the short pilot symbols.

    Abstract translation: 本发明采用诸如单载波FDM通信系统的频分多址(FDM)通信系统的导频方案。 给定的发送时间间隔将包括多个业务符号和两个或更多个短导频符号,它们彼此间隔开至少一个业务符号,并且将具有小于任何给定业务的傅里叶变换长度的傅里叶变换长度 符号。 多个发射机将产生导频信息,并以正交方式将导频信息调制到短导频符号的子载波上。 每个发射机可以在时间和频域内使用不同的子载波,由发射时间间隔内的短导频符号包围。 或者,每个发射机可以使用唯一的码分多路复用码对导频信息进行唯一的编码,并将编码的导频信息调制到短导频符号的公共子载波上。

    Methods and systems for OFDM using code division multiplexing
    67.
    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:US08902951B2

    公开(公告)日:2014-12-02

    申请号:US13944065

    申请日:2013-07-17

    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
    68.
    发明申请
    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:US20140219387A1

    公开(公告)日:2014-08-07

    申请号:US14251629

    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。

    Adaptive Two-Dimensional Channel Interpolation

    公开(公告)号:US20140079152A1

    公开(公告)日:2014-03-20

    申请号:US14088531

    申请日:2013-11-25

    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).

    Adaptive two-dimensional channel interpolation
    70.
    发明授权
    Adaptive two-dimensional channel interpolation 有权
    自适应二维信道插值

    公开(公告)号:US08619891B2

    公开(公告)日:2013-12-31

    申请号:US13666542

    申请日:2012-11-01

    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。

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