Methods and systems for resource allocation

    公开(公告)号:US11509431B2

    公开(公告)日:2022-11-22

    申请号:US16940286

    申请日:2020-07-27

    Applicant: Apple Inc.

    Abstract: Various methods and systems are provided for allocating time-frequency resources for downlink (DL) and uplink (UL) communications between base stations and mobile stations. Different forms of resource allocation messages including combinations of bitmaps and bitfields provide additional information about the resources and/or how they are assigned. In some implementations the resource allocation messages enable reduced overhead, which may ultimately improve transmission rates and/or the quality of transmissions.

    Methods and systems for resource allocation

    公开(公告)号:US10727989B2

    公开(公告)日:2020-07-28

    申请号:US16157413

    申请日:2018-10-11

    Applicant: Apple Inc.

    Abstract: Various methods and systems are provided for allocating time-frequency resources for downlink (DL) and uplink (UL) communications between base stations and mobile stations. Different forms of resource allocation messages including combinations of bitmaps and bitfields provide additional information about the resources and/or how they are assigned. In some implementations the resource allocation messages enable reduced overhead, which may ultimately improve transmission rates and/or the quality of transmissions.

    Method and System for Combining DFT-Transformed OFDM and Non-Transformed OFDM

    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.

    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

    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.

    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

    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.

    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).

    Communication of control information using alert flag and version number

    公开(公告)号:US10321440B2

    公开(公告)日:2019-06-11

    申请号:US15595404

    申请日:2017-05-15

    Applicant: Apple Inc.

    Abstract: To effectively and efficiently provide control information, a broadcast pointer channel (BPCH) may be used to identify the type and perhaps relative location of control information that is being provided in a given frame structure, such as a sub-frame, frame, or superframe. A sub-frame (or like framing entity, such a frame or superframe) may have a BPCH and a corresponding system control information segment in which control information may reside. The system control information segment may have any number of control information blocks, wherein each control information block that is present may correspond to a particular type of control information. The BPCH is used to identify the type of control information that is present in a corresponding system control information segment, and if needed or desired, the relative locations of the various control information.

    Preambles in OFDMA system
    60.
    发明授权

    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.

    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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