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公开(公告)号:US20130301685A1
公开(公告)日:2013-11-14
申请号:US13944065
申请日:2013-07-17
Applicant: Apple Inc.
Inventor: Jianglei Ma , Ming Jia , Wen Tong , Peiying Zhu , Hua Xu , Hang Zhang , Mo-Han Fong
IPC: H04B1/707
CPC classification number: H04J13/0003 , H04B1/707 , H04B7/0404 , H04B7/0678 , H04J13/00 , H04J13/16 , H04L5/0016 , H04L5/0026 , H04L5/0048 , H04L5/005 , H04L25/0204 , H04L25/0226 , H04L25/0232 , H04L25/03866 , H04L27/2613 , H04L27/2627 , H04W72/044
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.
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公开(公告)号:US20130136205A1
公开(公告)日:2013-05-30
申请号:US13666542
申请日:2012-11-01
Applicant: Apple Inc.
Inventor: Jianglei Ma , Ming Jia , Hua Xu , Wen Tong , Peiying Zhu , Dong-Sheng Yu , Hang Zhang
IPC: H04L27/26
CPC classification number: H04L27/2611 , H04B7/06 , H04B7/08 , H04L5/0007 , H04L5/0023 , H04L25/0226 , H04L25/0232 , H04L27/2626 , H04L27/2647
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).
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公开(公告)号:US20130128997A1
公开(公告)日:2013-05-23
申请号:US13665982
申请日:2012-11-01
Applicant: Apple Inc.
Inventor: Jianglei Ma , Ming Jia , Hua Xu , Wen Tong , Peiying Zhu , Dong-Sheng Yu , Hang Zhang
IPC: H04L5/00
CPC classification number: H04L27/2611 , H04B7/06 , H04B7/08 , H04L5/0007 , H04L5/0023 , H04L25/0226 , H04L25/0232 , H04L27/2626 , H04L27/2647
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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公开(公告)号:US11201648B2
公开(公告)日:2021-12-14
申请号:US16745516
申请日:2020-01-17
Applicant: Apple Inc.
Inventor: Wen Tong , Ming Jia , Jianglei Ma , Peiying Zhu , Hua Xu , Dong-Sheng Yu , Hang Zhang , Mo-Han Fong
IPC: H04B7/0456 , H04B7/06 , H04L5/00 , H04W48/08 , H04B7/0413 , H04W72/04 , H04W72/08 , H04W74/06 , H04L5/02 , H04L27/26
Abstract: Systems and methods for closed loop MIMO (multiple input and multiple output) wireless communication are provided. Various transmit formats including spatial multiplexing and STTD are defined in which vector or matrix weighting is employed using information fed back from receivers. The feedback information may include channel matrix or SVD-based feedback.
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公开(公告)号:US10700905B2
公开(公告)日:2020-06-30
申请号:US16666650
申请日:2019-10-29
Applicant: Apple Inc.
Inventor: Jianglei Ma , Ming Jia , Wen Tong , Peiying Zhu , Hang Zhang , Hua Xu , Dongsheng Yu
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).
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公开(公告)号:US20200177246A1
公开(公告)日:2020-06-04
申请号:US16786679
申请日:2020-02-10
Applicant: Apple Inc.
Inventor: Jianglei Ma , Ming Jia , Hua Xu , Wen Tong , Peiying Zhu , Moussa Abdi
IPC: H04B7/0452 , H04W72/04 , H04J13/18 , H04L5/00 , H04W88/08 , H04B7/0413 , H04L27/26
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.
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公开(公告)号:US10554272B2
公开(公告)日:2020-02-04
申请号:US15486060
申请日:2017-04-12
Applicant: APPLE INC.
Inventor: Wen Tong , Ming Jia , Jianglei Ma , Peiying Zhu , Hua Xu , Dong-Sheng Yu , Hang Zhang , Mo-Han Fong
IPC: H04B7/0456 , H04B7/06 , H04L5/00 , H04W48/08 , H04B7/0413 , H04W72/04 , H04L5/02 , H04W72/08 , H04W74/06 , H04L27/26
Abstract: Systems and methods for closed loop MIMO (multiple input and multiple output) wireless communication are provided. Various transmit formats including spatial multiplexing and STTD are defined in which vector or matrix weighting is employed using information fed back from receivers. The feedback information may include channel matrix or SVD-based feedback.
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公开(公告)号:US10374667B2
公开(公告)日:2019-08-06
申请号:US14496001
申请日:2014-09-25
Applicant: Apple Inc.
Inventor: Jianglei Ma , Ming Jia , Hua Xu , Wen Tong , Peiying Zhu , Moussa Abdi
IPC: H04B7/04 , H04B7/0452 , H04L5/00 , H04L27/26 , H04W72/04 , H04B7/0413 , H04W88/08 , H04J13/18 , H04L1/06 , H04L25/02 , H04J13/16
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.
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公开(公告)号:US10244529B2
公开(公告)日:2019-03-26
申请号:US15681557
申请日:2017-08-21
Applicant: Apple Inc.
Inventor: Hang Zhang , Jianglei Ma , Ming Jia , Sophie Vrzic , Mo-Han Fong , Dong-Sheng Yu , Hua Xu
IPC: H04W72/04 , H04B7/12 , H04L1/00 , H04L5/00 , H04L25/02 , H04L27/26 , H04L29/06 , H04B7/06 , H04L1/06 , H04L1/18 , H04L25/03 , H04B7/02
Abstract: Systems and methods for OFDM channelization are provided that allow for the coexistence of sub-band channels and diversity channels. Methods of defining diversity sub-channels and sub-band sub-channels are provided and systematic channel definition and labeling schemes are provided.
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公开(公告)号:US20190036576A1
公开(公告)日:2019-01-31
申请号:US16151636
申请日:2018-10-04
Applicant: Apple Inc.
Inventor: Jianglei Ma , Ming Jia , Hua Xu , Wen Tong , Peiying Zhu , Moussa Abdi
IPC: H04B7/0452 , H04W88/08 , H04B7/0413 , H04W72/04 , H04L27/26 , H04J13/18 , H04L5/00 , H04J13/16 , H04L1/06 , H04L25/02
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.
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