中科微点-全球专利检索

  1. Login
  2. Sign Up

Search Results

187 records (took 0.035 seconds)

    Pilot scheme for a MIMO communication system
    151.
    发明授权
    Pilot scheme for a MIMO communication system 有权

    公开(公告)号：US10797764B2

    公开(公告)日：2020-10-06

    申请号：US16519158

    申请日：2019-07-23

    Applicant: Apple Inc.

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

    IPC: H04W4/00 ,  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.

    Precoding in high-order MIMO
    152.
    发明授权
    Precoding in high-order MIMO 有权

    公开(公告)号：US10693535B2

    公开(公告)日：2020-06-23

    申请号：US15093924

    申请日：2016-04-08

    Applicant: Apple Inc.

    Inventor： Ming Jia ,  Jianglei Ma ,  Peiying Zhu ,  Wen Tong

    IPC: H04B7/0456 ,  H04B7/0417 ,  H04B7/06 ,  H04L25/03

    Abstract: A high-order Multiple-Input-Multiple-Output (MIMO) transmitter implementing a covariance-based precoding scheme that exploits transmit channel correlation and a method of operation thereof are provided. In one embodiment, covariance-based precoding is performed at the high-order MIMO transmitter based on feedback from a remote high-order MIMO receiver regarding a covariance-based precoding matrix. The covariance-based precoding matrix is, or is derived from, a transmit channel correlation matrix determined by the high-order MIMO receiver for the high-order MIMO transmitter. The covariance-based precoding provides a beam-forming effect when there is a relatively high degree of transmit channel correlation, thereby improving performance of the high-order MIMO transmitter. Further, because changes in the transmit channel correlation occur relatively slowly over time, feedback overhead requirements are substantially reduced as compared to that required for traditional MIMO precoding schemes.

    Pilot Symbol Patterns for Transmission through a Plurality of Antennas
    153.
    发明申请
    Pilot Symbol Patterns for Transmission through a Plurality of Antennas 审中-公开

    公开(公告)号：US20200067749A1

    公开(公告)日：2020-02-27

    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

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

    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).

    Method and system for combining DFT-transformed OFDM and non-transformed OFDM
    154.
    发明授权
    Method and system for combining DFT-transformed OFDM and non-transformed OFDM 有权

    公开(公告)号：US10554464B2

    公开(公告)日：2020-02-04

    申请号：US16273302

    申请日：2019-02-12

    Applicant: Apple Inc.

    Inventor： Jianglei Ma ,  Wen Tong ,  Ming Jia ,  Hua Xu ,  Peiying Zhu ,  Hang Zhang

    IPC: H04B7/005 ,  H04L27/26 ,  H04L1/00 ,  H04L5/00

    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.

    Wireless feedback system and method
    156.
    发明授权
    Wireless feedback system and method 有权

    公开(公告)号：US10340990B2

    公开(公告)日：2019-07-02

    申请号：US16049080

    申请日：2018-07-30

    Applicant: Apple Inc.

    Inventor： Wen Tong ,  Hosein Nikopour ,  Amir Khandani ,  Hua Xu ,  Ming Jia ,  Peiying Zhu ,  Dong-sheng Yu

    IPC: H04B7/04 ,  H04B7/0456 ,  H04B7/0417 ,  H04B7/06 ,  H04L29/06

    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.

    System access and synchronization methods for MIMO OFDM communications systems and physical layer packet and preamble design
    157.
    发明授权
    System access and synchronization methods for MIMO OFDM communications systems and physical layer packet and preamble design 有权

    公开(公告)号：US10237794B2

    公开(公告)日：2019-03-19

    申请号：US15355440

    申请日：2016-11-18

    Applicant: Apple Inc.

    Inventor： Jianglei Ma ,  Ming Jia ,  Peiying Zhu ,  Wen Tong

    IPC: H04W36/08 ,  H04B7/0413 ,  H04L27/26

    Abstract: A method and apparatus are provided for performing acquisition, synchronization and cell selection within an MIMO-OFDM communication system. A coarse synchronization is performed to determine a searching window. A fine synchronization is then performed by measuring correlations between subsets of signal samples, whose first signal sample lies within the searching window, and known values. The correlations are performed in the frequency domain of the received signal. In a multiple-output OFDM system, each antenna of the OFDM transmitter has a unique known value. The known value is transmitted as pairs of consecutive pilot symbols, each pair of pilot symbols being transmitted at the same subset of sub-carrier frequencies within the OFDM frame.

Patent Agency Ranking