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    Method and System for Combining DFT-Transformed OFDM and Non-Transformed OFDM
    141.
    发明申请
    Method and System for Combining DFT-Transformed OFDM and Non-Transformed OFDM 审中-公开

    公开(公告)号：US20200177422A1

    公开(公告)日：2020-06-04

    申请号：US16780620

    申请日：2020-02-03

    Applicant: Apple Inc.

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

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

    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.

    Methods and systems for OFDM using code division multiplexing
    142.
    发明授权
    Methods and systems for OFDM using code division multiplexing 有权

    公开(公告)号：US10541773B2

    公开(公告)日：2020-01-21

    申请号：US16374147

    申请日：2019-04-03

    Applicant: Apple Inc.

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

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

    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.

    Pilot symbol patterns for transmission through a plurality of antennas
    143.
    发明授权
    Pilot symbol patterns for transmission through a plurality of antennas 有权

    公开(公告)号：US10476719B2

    公开(公告)日：2019-11-12

    申请号：US16433273

    申请日：2019-06-06

    Applicant: Apple Inc.

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

    IPC: H04L27/26 ,  H04L25/02 ,  H04L5/00 ,  H04B7/06 ,  H04B7/08 ,  H04W52/32 ,  H04L1/00 ,  H04L1/06

    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).

    Frame structure for allocating radio resources in a cellular wireless network
    145.
    发明授权
    Frame structure for allocating radio resources in a cellular wireless network 有权

    公开(公告)号：US10244398B2

    公开(公告)日：2019-03-26

    申请号：US15631921

    申请日：2017-06-23

    Applicant: Apple Inc.

    Inventor： James Mark Naden ,  Peiying Zhu

    IPC: H04W72/04 ,  H04W16/12 ,  H04B7/155 ,  H04B7/26 ,  H04W84/04 ,  H04L27/26 ,  H04L5/00

    Abstract: The capacity of a cellular wireless system is increased by operation of base stations or base station sectors arranged to re-use radio resource elements that are used by neighboring base stations or base station sectors, in conjunction with operation of relay stations, which are similarly arranged to re-use radio resource elements used by neighboring relay stations, and where the radio resource elements re-used by the relay stations are different to those used by the base stations. The relay stations provide coverage, particularly in the areas at the boundaries between the areas of coverage of base stations that suffer from interference between signals transmitted from the respective base stations. In addition, the relay stations generally increase the average available carrier to interference ratio compared with a system in which base stations alone are deployed. The scheme for the allocation of radio resource elements ensures in particular that interference is avoided between signals transmitted from a base station and signals transmitted from a relay station in radio resource elements allocated to control data.

    Preambles in OFDMA system
    146.
    发明授权
    Preambles in OFDMA system 有权

    公开(公告)号：US10212017B2

    公开(公告)日：2019-02-19

    申请号：US15823072

    申请日：2017-11-27

    Applicant: APPLE INC.

    Inventor： Jianglei Ma ,  Hang Zhang ,  Wen Tong ,  Ming Jia ,  Peiying Zhu ,  Mo-Han Fong

    IPC: H04L27/26 ,  H04B7/02 ,  H04L5/00 ,  H04W24/02 ,  H04B7/0452 ,  H04L7/04

    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.

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