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    Pilot scheme for a MIMO communication system
    3.
    发明授权
    Pilot scheme for a MIMO communication system 有权

    公开(公告)号：US11349531B2

    公开(公告)日：2022-05-31

    申请号：US17009405

    申请日：2020-09-01

    申请人： Apple Inc.

    发明人： Jianglei Ma ,  Ming Jia ,  Hua Xu ,  Wen Tong ,  Peiying Zhu ,  Moussa Abdi

    IPC分类号： H04W4/00 ,  H04B7/0452 ,  H04L5/00 ,  H04L27/26 ,  H04W72/04 ,  H04B7/0413 ,  H04W88/08 ,  H04J13/18 ,  H04L1/06 ,  H04L25/02 ,  H04J13/16

    摘要： 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.

    Pilot scheme for a MIMO communication system
    4.
    发明授权
    Pilot scheme for a MIMO communication system 有权

    公开(公告)号：US11223397B2

    公开(公告)日：2022-01-11

    申请号：US16786679

    申请日：2020-02-10

    申请人： Apple Inc.

    发明人： Jianglei Ma ,  Ming Jia ,  Hua Xu ,  Wen Tong ,  Peiying Zhu ,  Moussa Abdi

    IPC分类号： H04W4/00 ,  H04B7/0452 ,  H04L5/00 ,  H04L27/26 ,  H04W72/04 ,  H04B7/0413 ,  H04W88/08 ,  H04J13/18 ,  H04L1/06 ,  H04L25/02 ,  H04J13/16

    摘要： 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.

    Methods and systems for OFDM using code division multiplexing
    8.
    发明授权
    Methods and systems for OFDM using code division multiplexing 有权

    公开(公告)号：US10862609B2

    公开(公告)日：2020-12-08

    申请号：US16716845

    申请日：2019-12-17

    申请人： Apple Inc.

    发明人： Jianglei Ma ,  Ming Jia ,  Wen Tong ,  Peiying Zhu ,  Hua Xu ,  Hang Zhang ,  Mo-Han Fong

    IPC分类号： H04J13/00 ,  H04B7/06 ,  H04L5/00 ,  H04L25/02 ,  H04L27/26 ,  H04B1/707 ,  H04B7/0404 ,  H04W72/04 ,  H04J13/16 ,  H04L25/03

    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.

    Pilot Symbol Patterns for Transmission through a Plurality of Antennas
    9.
    发明申请
    Pilot Symbol Patterns for Transmission through a Plurality of Antennas 审中-公开

    公开(公告)号：US20200328923A1

    公开(公告)日：2020-10-15

    申请号：US16915764

    申请日：2020-06-29

    申请人： Apple Inc.

    发明人： Jianglei Ma ,  Ming Jia ,  Wen Tong ,  Peiying Zhu ,  Hang Zhang ,  Hua Xu ,  Dongsheng Yu

    IPC分类号： H04L27/26 ,  H04L5/00 ,  H04W52/32 ,  H04L25/02 ,  H04B7/06 ,  H04B7/08

    摘要： 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).