Medium access control for wireless systems

    公开(公告)号:US10701624B2

    公开(公告)日:2020-06-30

    申请号:US16223409

    申请日:2018-12-18

    Applicant: APPLE INC.

    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.

    Methods and Systems for OFDM Using Code Division Multiplexing

    公开(公告)号:US20200119827A1

    公开(公告)日:2020-04-16

    申请号:US16716845

    申请日:2019-12-17

    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.

    Systems and methods for use with orthogonal frequency division multiplexing

    公开(公告)号:US10439784B2

    公开(公告)日:2019-10-08

    申请号:US15494804

    申请日:2017-04-24

    Applicant: APPLE INC.

    Abstract: Systems and methods are provided for enabling H-ARQ communication between a base station and one or more wireless terminals. Methods for enabling incremental redundancy (IR) based H-ARQ, Chase based H-ARQ and Space-Time Code combining (STC) based H-ARQ between devices for down-link and up-link direction transmissions are provided in the form of an information element (IE) for use with a Normal MAP convention as currently accepted in the draft version standard of IEEE 802.16. In addition, embodiments of the invention provide a resource management scheme to protect a network from abuse of resources from a wireless terminal not registered with the network. Components of the down-link and up-link mapping components of a data frame transmitted from the base station to one or more wireless terminals included messages that are readable by all wireless terminals as well as some messages that are encrypted and only readable by wireless terminals that are authenticated as being registered with the network.

    Pilot Symbol Patterns for Transmission through a Plurality of Antennas

    公开(公告)号:US20190288893A1

    公开(公告)日:2019-09-19

    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).

    Multimedia broadcast multicast service (MBMS) utilizing spatial multiplexing

    公开(公告)号:US10349229B2

    公开(公告)日:2019-07-09

    申请号:US15730111

    申请日:2017-10-11

    Applicant: Apple Inc.

    Abstract: Systems and methods are disclosed herein for an enhanced Multimedia Broadcast Multicast Service (MBMS) in a wireless communications network. In one embodiment, a number of base stations in a MBMS zone, or broadcast region, accommodate both Spatial Multiplexing (SM) enabled user elements and non-SM enabled user elements. In another embodiment, a number of base stations form a MBMS zone, or broadcast region, where the MBMS zone is sub-divided into an SM zone and a non-SM zone. In another embodiment, the wireless communications network includes multiple MBMS zones. For each MBMS zone, base stations serving the MBMS zone transmit an MBMS zone identifier (ID) for the MBMS zone. The MBMS zone ID may be used by a user element for decoding and/or to determine when to perform a handoff from one MBMS zone to another.

    Pilot symbol patterns for transmission through a plurality of antennas

    公开(公告)号:US10348542B2

    公开(公告)日:2019-07-09

    申请号:US16255702

    申请日:2019-01-23

    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).

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