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    Methods and systems for OFDM using code division multiplexing
    21.
    发明授权
    Methods and systems for OFDM using code division multiplexing 有权

    公开(公告)号：US10284322B2

    公开(公告)日：2019-05-07

    申请号：US16031047

    申请日：2018-07-10

    Applicant: Apple Inc.

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

    IPC: H04L5/00 ,  H04B1/707 ,  H04L27/26 ,  H04W72/04 ,  H04B7/0404 ,  H04J13/00 ,  H04L25/02 ,  H04B7/06 ,  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
    22.
    发明授权
    Pilot symbol patterns for transmission through a plurality of antennas 有权

    公开(公告)号：US10200226B2

    公开(公告)日：2019-02-05

    申请号：US16110205

    申请日：2018-08-23

    Applicant: Apple Inc.

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

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

    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).

    Medium access control for wireless systems
    23.
    发明授权
    Medium access control for wireless systems 有权

    公开(公告)号：US10165501B2

    公开(公告)日：2018-12-25

    申请号：US14733656

    申请日：2015-06-08

    Applicant: APPLE INC.

    Inventor： Mo-Han Fong ,  Hang Zhang ,  Robert Novak

    IPC: H04W48/16 ,  H04L29/06 ,  H04W8/26 ,  H04W52/26 ,  H04W24/00 ,  H04W74/00

    Abstract: A method for execution by a mobile station (MS) in a mobile communications network, the method comprising: receiving a first MS identifier from the network during a ranging operation involving the MS; using the first MS identifier to extract the contents of at least one message received from the network during said ranging operation; using a second MS identifier, different from the first MS identifier, to extract the contents of at least one message received from the network after said ranging operation is complete. Also, a method for execution by the base station, comprising: outputting a first message destined for the MS, the first message including a first identifier for use by the MS during a ranging operation; determining that said ranging operation is complete; outputting a second message destined for the MS, the second message including a second identifier for use by the MS in subsequent communication with the network.

    Handoffs and handoff selection in a wireless access network
    24.
    发明授权
    Handoffs and handoff selection in a wireless access network 有权

    公开(公告)号：US10091693B2

    公开(公告)日：2018-10-02

    申请号：US14546732

    申请日：2014-11-18

    Applicant: APPLE INC.

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

    IPC: H04W36/00 ,  H04W36/30 ,  H04W36/18

    Abstract: The present invention facilitates handoffs for a mobile terminal in a wireless access network that is capable of supporting different types of handoffs. The different handoff types may include soft handoffs and fast base station switching (FBSS). In operation, context information associated with supporting wireless communications between the wireless access network and the mobile terminal are determined. Based on whether the context information is shared between base stations involved in the handoff or transferred from one base station to another of the base stations involved in the handoff, a particular handoff type is selected from the different handoff types that are available. Selecting the specific type of handoff to use may also be based on the level of context information that is available, the actual content of the context information, application preferences, channel conditions, base station or mobile terminal capabilities, or any combination thereof.

    Methods and systems for OFDM using code division multiplexing
    27.
    发明授权
    Methods and systems for OFDM using code division multiplexing 有权

    公开(公告)号：US10044460B2

    公开(公告)日：2018-08-07

    申请号：US15399028

    申请日：2017-01-05

    Applicant: Apple Inc.

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

    IPC: H04B1/00 ,  H04J13/00 ,  H04B1/707 ,  H04L5/00

    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.

    Method and system for combining DFT-transformed OFDM and non-transformed OFDM
    30.
    发明授权
    Method and system for combining DFT-transformed OFDM and non-transformed OFDM 有权

    公开(公告)号：US09825793B2

    公开(公告)日：2017-11-21

    申请号：US15195083

    申请日：2016-06-28

    Applicant: Apple Inc.

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

    IPC: 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.

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