Patent Description:
For mMTC applications, a base station is expected to accommodate a very large number of low-cost user equipment. The data traffic generated by each mMTC user equipment (UE) is expected to be both light and sporadic. The signaling overhead and wireless network traffic of the scheduling grants associated with each uplink transmission in conventional wireless communication system is inefficient for mMTC UEs and applications.

<CIT> describes method and apparatus for transmitting a control signal associated with uplink data transmission by a terminal when the terminal performs uplink transmission.

This summary is provided to introduce simplified concepts of beamforming-based grant-free non-orthogonal multiple access transmission. The simplified concepts are further described below in the Detailed Description. This summary is not intended to identify essential features of the claimed subject matter, nor is it intended for use in determining the scope of the claimed subject matter.

In some aspects, configuring beamformed wireless communication between a base station and a user equipment is described, in which the base station transmits, using multiple transmit antenna configurations, downlink reference signals to the user equipment, configures time-frequency resources for Non-Orthogonal Multiple Access (NOMA) transmission by the user equipment, and configures an association between the downlink reference signals and the time-frequency resources for the user equipment. The base station transmits the configuration of the time-frequency resources and the association between the downlink reference signals and the time-frequency resources to the user equipment. The base station receives uplink data from the user equipment on one of the time-frequency resources using a receive antenna configuration, the receive antenna configuration being determined at least in part using one of the multiple transmit antenna configurations used for transmitting one of the downlink reference signals associated with the one of the time-frequency resources as indicated in the association.

In other aspects, beamformed communication between a base station and a user equipment is described, in which the user equipment receives, using multiple receive antenna configurations, downlink reference signals from the base station, receives a configuration of time-frequency resources for Non-Orthogonal Multiple Access (NOMA) transmission from the base station, and receives an association between the downlink reference signals and the time-frequency resources from the base station. The user equipment transmits uplink data to the base station on one of the time-frequency resources using a transmit antenna configuration, the transmit antenna configuration being determined, at least in part, using one of the multiple receive antenna configurations used for receiving one of the downlink reference signals which is associated with the one of the time-frequency resources as indicated in the association.

Aspects of beamforming-based grant-free non-orthogonal multiple access transmission are described with reference to the following drawings. The same numbers are used throughout the drawings to reference like features and components:.

In aspects of grant-free uplink (UL) transmission, user devices perform uplink transmissions autonomously without the transmissions being scheduled by a base station. The base station receives the uplink transmissions using a predefined detection and/or decoding method. The use of grant-free transmissions is particularly suited to the low-duty cycle and/or sporadic communication needs of massive machine type communications (mMTC) user equipment, systems, and applications. The benefits of grant-free uplink transmissions are also applicable to many ultra-reliable low latency communications (URLLC) user equipment, systems, and applications. Grant-free uplink transmissions may also be applied in a unified framework for all fifth generation new radio (5GNR) user equipment, systems, base stations, and application scenarios.

Within the context of grant-free uplink transmissions, non-orthogonal multiple access (NOMA) can be utilized as a multiple access scheme. In NOMA, the user equipment performs grant-free uplink transmissions with resources that are not necessarily orthogonal to each other. A resource used by a user equipment for NOMA transmission is typically described as a multiple access (MA) signature (e.g., orthogonal codes, spreading codes, scrambling codes, mapping patterns, etc.). A larger number of user equipment can be simultaneously supported using NOMA than can be supported using orthogonal resources. For uplink detection, the base station blindly decodes all the possible MA signatures since uplink transmissions are not pre-scheduled but are made autonomously by the UEs. To lower decoding complexity, the MA signatures can be associated with preambles and/or demodulation reference symbols that are based on a predefined mapping mechanism. For example, if preambles and MA signatures have a one-to-one mapping, the base station can simply detect the presence of a particular preamble to see if the associated user equipment made an uplink transmission instead of decoding an entire uplink transmission of a user equipment to detect the identity of the user equipment.

In <NUM> NR systems, beamforming is expected to be heavily utilized to overcome signal attenuation in higher-frequency radio bands. A transmit-receive beam refers to signals generated by applying a specific transmit-receive antenna configuration in a multi-antenna communication device. The transmit-receive beam comprises a specific pattern of spatial filtering that is applied to output signals for transmission. In the case of digital beamforming, the spatial filtering is performed in the radio baseband and can be done by applying weighting coefficients to the complex baseband signal values. With increasing numbers of antenna elements, the cost of performing beamforming in the baseband also increases. Analog beamforming, on the other hand, performs spatial filtering on the radio frequency (RF) signals directly, and can be achieved by adjusting the transmission or reception timing of the RF signals on different antenna elements. For example, the timing adjustment is achieved by coupling a phase shifter to each antenna element. Conceptually, a transmit-receive beam can be thought of as applying a specific setting to the array of phase shifters.

In this document, a transmit antenna configuration refers to a specific transmit beam pattern. Similarly, a receive antenna configuration refers to a specific receive beam pattern.

Beam sweeping is an operation where different spatial filtering patterns are applied continuously in the time domain to cover different spatial directions in analog beamforming. Transmit beam sweeping is a process where a communication device transmits the same signal in consecutive time slots using different transmit beams. Similarly, receive beam sweeping is the process where a device receives the same signal in consecutive time slots using different receive beams.

Beam correspondence between transmit beams and receive beams at a base station can be achieved if at least one of the following is satisfied:.

Similarly, beam correspondence between transmit beams and receive beams at a user equipment can be achieved if at least one of the following is satisfied:.

In <NUM> NR systems, signals used for initial access to the wireless network by the user equipment include several synchronization signal blocks (SSBs). An SSB includes a primary synchronization signal, a secondary synchronization signal, and a physical broadcast channel (PBCH). A DL reference signal (RS) is a special signal transmitted by the base station on a regular (e.g., periodic) basis for measurement and reporting purposes by the UE. In <NUM> NR systems, channel state information-reference signals (CSI-RSs) and/or SSBs can serve as the downlink reference signals (DL RSs).

<FIG> illustrates an example environment <NUM> which includes a user equipment <NUM> (UE <NUM>) that can communicate with base stations <NUM> (illustrated as base stations <NUM> and <NUM>) through wireless communication links <NUM> (wireless link <NUM>), illustrated as wireless links <NUM> and <NUM>. For simplicity, the UE <NUM> is implemented as a smartphone but may be implemented as any suitable computing or electronic device, such as a mobile communication device, modem, cellular phone, gaming device, navigation device, media device, laptop computer, desktop computer, tablet computer, smart appliance, vehicle-based communication system, or an Internet-of-Things (IoT) device such as a sensor or an actuator. The base stations <NUM> (e.g., an Evolved Universal Terrestrial Radio Access Network Node B, E-UTRAN Node B, evolved Node B, eNodeB, eNB, Next Generation Node B, gNode B, gNB, or the like) may be implemented in a macrocell, microcell, small cell, picocell, and the like, or any combination thereof.

The base stations <NUM> communicate with the user equipment <NUM> using the wireless links <NUM> and <NUM>, which may be implemented as any suitable type of wireless link. The wireless links <NUM> and <NUM> include control and data communication, such as downlink of data and control information communicated from the base stations <NUM> to the user equipment <NUM>, uplink of other data and control information communicated from the user equipment <NUM> to the base stations <NUM>, or both. The wireless links <NUM> may include one or more wireless links (e.g., radio links) or bearers implemented using any suitable communication protocol or standard, or combination of communication protocols or standards, such as 3rd Generation Partnership Project Long-Term Evolution (3GPP LTE), Fifth Generation New Radio (5GNR), and so forth. Multiple wireless links <NUM> may be aggregated in a carrier aggregation to provide a higher data rate for the UE <NUM>. Multiple wireless links <NUM> from multiple base stations <NUM> may be configured for Coordinated Multipoint (CoMP) communication with the UE <NUM>.

The base stations <NUM> are collectively a Radio Access Network <NUM> (e.g., RAN, Evolved Universal Terrestrial Radio Access Network, E-UTRAN, <NUM> NR RAN or NR RAN). The base stations <NUM> and <NUM> in the RAN <NUM> are connected to a core network <NUM>. The base stations <NUM> and <NUM> connect, at <NUM> and <NUM> respectively, to the core network <NUM> through an NG2 interface for control-plane signaling and using an NG3 interface for user-plane data communications when connecting to a <NUM> core network, or using an S1 interface for control-plane signaling and user-plane data communications when connecting to an Evolved Packet Core (EPC) network. The base stations <NUM> and <NUM> can communicate using an Xn Application Protocol (XnAP) through an Xn interface, or using an X2 Application Protocol (X2AP) through an X2 interface, at <NUM>, to exchange user-plane and control-plane data. The user equipment <NUM> may connect, via the core network <NUM>, to public networks, such as the Internet <NUM> to interact with a remote service <NUM>.

<FIG> illustrates an example device diagram <NUM> of the user equipment <NUM> and the base stations <NUM>. The user equipment <NUM> and the base stations <NUM> may include additional functions and interfaces that are omitted from <FIG> for the sake of clarity. The user equipment <NUM> includes antennas <NUM>, a radio frequency front end <NUM> (RF front end <NUM>), an LTE transceiver <NUM>, and a <NUM> NR transceiver <NUM> for communicating with base stations <NUM> in the RAN <NUM>. The RF front end <NUM> of the user equipment <NUM> can couple or connect the LTE transceiver <NUM>, and the <NUM> NR transceiver <NUM> to the antennas <NUM> to facilitate various types of wireless communication. The antennas <NUM> of the user equipment <NUM> may include an array of multiple antennas that are configured similar to or differently from each other. The antennas <NUM> and the RF front end <NUM> can be tuned to, and/or be tunable to, one or more frequency bands defined by the 3GPP LTE and <NUM> NR communication standards and implemented by the LTE transceiver <NUM>, and/or the <NUM> NR transceiver <NUM>. Additionally, the antennas <NUM>, the RF front end <NUM>, the LTE transceiver <NUM>, and/or the <NUM> NR transceiver <NUM> may be configured to support beamforming for the transmission and reception of communications with the base stations <NUM>. By way of example and not limitation, the antennas <NUM> and the RF front end <NUM> can be implemented for operation in sub-gigahertz bands, sub-<NUM> bands, and/or above <NUM> bands that are defined by the 3GPP LTE and <NUM> NR communication standards.

The user equipment <NUM> also includes processor(s) <NUM> and computer-readable storage media <NUM> (CRM <NUM>). The processor <NUM> may be a single core processor or a multiple core processor composed of a variety of materials, such as silicon, polysilicon, high-K dielectric, copper, and so on. The computer-readable storage media described herein excludes propagating signals. CRM <NUM> may include any suitable memory or storage device such as random-access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), non-volatile RAM (NVRAM), read-only memory (ROM), or Flash memory useable to store device data <NUM> of the user equipment <NUM>. The device data <NUM> includes user data, multimedia data, beamforming codebooks, applications, and/or an operating system of the user equipment <NUM>, which are executable by processor(s) <NUM> to enable user-plane communication, control-plane signaling, and user interaction with the user equipment <NUM>.

In some implementations, the CRM <NUM> may also include a beam tracking manager <NUM>. Alternately or additionally, the beam tracking manager <NUM> may be implemented in whole or part as hardware logic or circuitry integrated with or separate from other components of the user equipment <NUM>. The beam tracking manager <NUM> can communicate with the antennas <NUM>, the RF front end <NUM>, the LTE transceiver <NUM>, and/or the <NUM> NR transceiver <NUM> to monitor the quality of the wireless communication links <NUM> and initiate a beam search based on the monitored quality of the wireless communication links <NUM>.

The device diagram for the base stations <NUM>, shown in <FIG>, includes a single network node (e.g., a gNode B). The functionality of the base stations <NUM> may be distributed across multiple network nodes or devices and may be distributed in any fashion suitable to perform the functions described herein. The base stations <NUM> include antennas <NUM>, a radio frequency front end <NUM> (RF front end <NUM>), one or more LTE transceivers <NUM>, and/or one or more <NUM> NR transceivers <NUM> for communicating with the UE <NUM>. The RF front end <NUM> of the base stations <NUM> can couple or connect the LTE transceivers <NUM> and the 5GNR transceivers <NUM> to the antennas <NUM> to facilitate various types of wireless communication. The antennas <NUM> of the base stations <NUM> may include an array of multiple antennas that are configured similar to or differently from each other. The antennas <NUM> and the RF front end <NUM> can be tuned to, and/or be tunable to, one or more frequency band defined by the 3GPP LTE and <NUM> NR communication standards, and implemented by the LTE transceivers <NUM>, and/or the <NUM> NR transceivers <NUM>. Additionally, the antennas <NUM>, the RF front end <NUM>, the LTE transceivers <NUM>, and/or the <NUM> NR transceivers <NUM> may be configured to support beamforming, such as Massive-MIMO, for the transmission and reception of communications with the UE <NUM>.

The base stations <NUM> also include processor(s) <NUM> and computer-readable storage media <NUM> (CRM <NUM>). The processor <NUM> may be a single core processor or a multiple core processor composed of a variety of materials, such as silicon, polysilicon, high-K dielectric, copper, and so on. CRM <NUM> may include any suitable memory or storage device such as random-access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), non-volatile RAM (NVRAM), read-only memory (ROM), or Flash memory useable to store device data <NUM> of the base stations <NUM>. The device data <NUM> includes network scheduling data, radio resource management data, beamforming codebooks, applications, and/or an operating system of the base stations <NUM>, which are executable by processor(s) <NUM> to enable communication with the user equipment <NUM>.

CRM <NUM> also includes a resource manager <NUM>. Alternately or additionally, the resource manager <NUM> may be implemented in whole or part as hardware logic or circuitry integrated with or separate from other components of the base stations <NUM>. In at least some aspects, the resource manager <NUM> configures the LTE transceivers <NUM> and the <NUM> NR transceivers <NUM> for communication with the user equipment <NUM>, as well as communication with a core network, such as the core network <NUM>.

The base stations <NUM> include an inter-base station interface <NUM>, such as an Xn and/or X2 interface, which the resource manager <NUM> configures to exchange user-plane and control-plane data between other base stations <NUM>, to manage the communication of the base stations <NUM> with the user equipment <NUM>. The base stations <NUM> include a core network interface <NUM> that the resource manager <NUM> configures to exchange user-plane and control-plane data with core network functions and/or entities.

When operating in higher-frequency radio bands, beamforming is applied at both the transmitting and the receiving end of a wireless communication link to extend the communication range (distance). Appropriate beamforming weights are established and maintained after a user equipment <NUM> enters an RRC_CONNECTED state and through a series of related signaling communications. As a grant-free (GF) NOMA transmission is made autonomously by a user equipment <NUM>, and the user equipment <NUM> may be in a state other than the RRC_CONNECTED state, how the user equipment <NUM> determines the appropriate transmit beam for transmissions to the base station <NUM> has not been defined. How the base station <NUM> determines the appropriate receive beam for receiving uplink NOMA transmission from the user equipment <NUM> is also undefined.

In aspects, to provide transmit beam determination for the user equipment <NUM>, as well as receive beam determination for the base station <NUM>, the base station <NUM> transmits multiple DL RSs, with each DL RS applying spatial filtering patterns to transmit on different transmit beams. The base station <NUM> then configures time-frequency resources dedicated to NOMA transmission by the user equipment <NUM>. The base station <NUM> further configures an association between the multiple DL RSs and the time-frequency resources, such that each DL RS has an associated time-frequency resource. Optionally or additionally, MA signatures can be associated with preambles and/or demodulation reference symbols that are based on a predefined mapping mechanism, as described above.

Before attempting to perform a NOMA transmission, the user equipment <NUM> receives the DL RSs. By receiving the DL RSs, the user equipment <NUM> determines which one of the DL RSs yields the best reception quality (e.g., the highest reference signal received power (RSRP)). Also, the user equipment <NUM> determines a receive beam for reception of the DL RSs based on measurements of downlink transmissions received by the user equipment <NUM>. Using the association indicated by the base station <NUM>, the user equipment <NUM> determines one of the time-frequency resources which is associated with the one of the DL RSs. Finally, the user equipment <NUM> applies the principle of beam correspondence, as described above and performs a NOMA transmission on the one of the time-frequency resources using a transmit beam which is determined based on at least the receive beam used to receive the one of the DL RSs.

In another aspect, the base station <NUM> attempts to detect uplink NOMA transmissions on each of the time-frequency resources. When detecting a particular time-frequency resource, the base station <NUM> first determines a DL RS which is associated with the particular time-frequency resource based on the association relationship. Applying the principle of beam correspondence, the base station <NUM> then determines a receive beam based on at least the transmit beam which is used for transmitting the DL RS. Optionally or additionally, if MA signatures are associated with preambles and/or demodulation reference symbols, the base station <NUM> can simply detect the presence of a particular preamble to see if the associated user equipment <NUM> made an uplink transmission instead of decoding an entire uplink transmission of a user equipment <NUM> to detect the identity of the user equipment.

In a further aspect, the time-frequency resources can also be associated with the DL RSs in an indirect fashion. For example, the base station <NUM> can configure an association between the DL RSs and multiple Physical Random Access Channel (PRACH) resources and configure another association between the time-frequency resources used for NOMA transmissions with the PRACH resources.

<FIG> illustrates an air interface resource that extends between a user equipment and a base station and with which various aspects of user equipment-initiated beam search for fifth generation new radio can be implemented. The air interface resource <NUM> can be divided into resource units <NUM>, each of which occupies some intersection of frequency spectrum and elapsed time. A portion of the air interface resource <NUM> is illustrated graphically in a grid or matrix having multiple resource blocks <NUM>, including example resource blocks <NUM>, <NUM>, <NUM>, <NUM>. An example of a resource unit <NUM> therefore includes at least one resource block <NUM>. As shown, time is depicted along the horizontal dimension as the abscissa axis, and frequency is depicted along the vertical dimension as the ordinate axis. The air interface resource <NUM>, as defined by a given communication protocol or standard, may span any suitable specified frequency range, and/or may be divided into intervals of any specified duration. Increments of time can correspond to, for example, milliseconds (mSec). Increments of frequency can correspond to, for example, megahertz (MHz).

In example operations generally, the base stations <NUM> allocate portions (e.g., resource units <NUM>) of the air interface resource <NUM> for uplink and downlink communications. Each resource block <NUM> of network access resources may be allocated to support respective wireless communication links <NUM> of multiple user equipment <NUM>. In the lower left corner of the grid, the resource block <NUM> may span, as defined by a given communication protocol, a specified frequency range <NUM> and comprise multiple subcarriers or frequency sub-bands. The resource block <NUM> may include any suitable number of subcarriers (e.g., <NUM>) that each correspond to a respective portion (e.g., <NUM>) of the specified frequency range <NUM> (e.g., <NUM>). The resource block <NUM> may also span, as defined by the given communication protocol, a specified time interval <NUM> or time slot (e.g., lasting approximately one-half millisecond or <NUM> orthogonal frequency-division multiplexing (OFDM) symbols). The time interval <NUM> includes subintervals that may each correspond to a symbol, such as an OFDM symbol. As shown in <FIG>, each resource block <NUM> may include multiple resource elements <NUM> (REs) that correspond to, or are defined by, a subcarrier of the frequency range <NUM> and a subinterval (or symbol) of the time interval <NUM>. Alternatively, a given resource element <NUM> may span more than one frequency subcarrier or symbol. Thus, a resource unit <NUM> may include at least one resource block <NUM>, at least one resource element <NUM>, and so forth.

In example implementations, multiple user equipment <NUM> (one of which is shown) are communicating with the base stations <NUM> (one of which is shown) through access provided by portions of the air interface resource <NUM>. The resource manager <NUM> (shown in <FIG>) may determine a respective data-rate, type of information, or amount of information (e.g., data or control information) to be communicated (e.g., transmitted) by the user equipment <NUM>. For example, the resource manager <NUM> can determine that each user equipment <NUM> is to transmit at a different respective data rate or transmit a different respective amount of information. The resource manager <NUM> then allocates one or more resource blocks <NUM> to each user equipment <NUM> based on the determined data rate or amount of information.

Additionally or in the alternative to block-level resource grants, the resource manager <NUM> may allocate resource units at an element-level. Thus, the resource manager <NUM> may allocate one or more resource elements <NUM> or individual subcarriers to different user equipment <NUM>. By so doing, one resource block <NUM> can be allocated to facilitate network access for multiple user equipment <NUM>. Accordingly, the resource manager <NUM> may allocate, at various granularities, one or up to all subcarriers or resource elements <NUM> of a resource block <NUM> to one user equipment <NUM> or divided across multiple user equipment <NUM>, thereby enabling higher network utilization or increased spectrum efficiency.

The resource manager <NUM> can therefore allocate air interface resource <NUM> by resource unit <NUM>, resource block <NUM>, frequency carrier, time interval, resource element <NUM>, frequency subcarrier, time subinterval, symbol, spreading code, some combination thereof, and so forth. Based on respective allocations of resource units <NUM>, the resource manager <NUM> can transmit respective messages to the multiple user equipment <NUM> indicating the respective allocation of resource units <NUM> to each user equipment <NUM>. Each message may enable a respective user equipment <NUM> to queue the information or configure the LTE transceiver <NUM>, the <NUM> NR transceiver <NUM>, or both to communicate via the allocated resource units <NUM> of the air interface resource <NUM>.

Example methods <NUM> and <NUM> are described with reference to <FIG> and <FIG> in accordance with one or more aspects of beamforming-based grant-free non-orthogonal multiple access transmission. The order in which the method blocks are described are not intended to be construed as a limitation, and any number of the described method blocks can be skipped or combined in any order to implement a method or an alternate method. Generally, any of the components, modules, methods, and operations described herein can be implemented using software, firmware, hardware (e.g., fixed logic circuitry), manual processing, or any combination thereof. Some operations of the example methods may be described in the general context of executable instructions stored on computer-readable storage memory that is local and/or remote to a computer processing system, and implementations can include software applications, programs, functions, and the like. Alternatively or in addition, any of the functionality described herein can be performed, at least in part, by one or more hardware logic components, such as, and without limitation, Field-programmable Gate Arrays (FPGAs), Application-specific Integrated Circuits (ASICs), Application-specific Standard Products (ASSPs), System-on-a-chip systems (SoCs), Complex Programmable Logic Devices (CPLDs), and the like.

<FIG> illustrates example method(s) <NUM> of beamforming-based grant-free non-orthogonal multiple access transmission as generally related to communications by the base station <NUM>. At block <NUM>, a base station transmits, using multiple transmit antenna configurations, multiple downlink reference signals to a user equipment. For example, the base station <NUM> transmits multiple downlink signals using multiple transmit antenna configurations of the antennas <NUM>.

At block <NUM>, the base station configures time-frequency resources for Non-Orthogonal Multiple Access (NOMA) transmissions by the user equipment. For example, the base station <NUM> selects a configuration of resource elements <NUM> in the frequency domain, the time domain, or both, for NOMA transmissions by the user equipment <NUM>.

At block <NUM>, the base station configures an association between the downlink reference signals and the time-frequency resources for the user equipment. For example, the base station <NUM> configures an association between the downlink reference signals and the time-frequency resources for the user equipment <NUM>.

At block <NUM>, the base station transmits the configuration of the time-frequency resources and the association between the downlink reference signals and the time-frequency resources to the user equipment. For example, the base station <NUM> transmits the configuration of the time-frequency resources and the association between the downlink reference signals and the time-frequency resources to the user equipment <NUM>.

At block <NUM>, the base station receives uplink data from the user equipment on one of the time-frequency resources using a receive antenna configuration. For example, the base station <NUM> receives uplink data from the user equipment <NUM> on one of the time-frequency resources using a receive antenna configuration for the antennas <NUM>.

<FIG> illustrates example method(s) <NUM> of beamforming-based grant-free non-orthogonal multiple access transmission as generally related to the user equipment <NUM>. At block <NUM>, a user equipment receives, using multiple receive antenna configurations, downlink reference signals from a base station. For example, the user equipment <NUM> receives downlink reference signals from the base station <NUM> using multiple receive antenna configurations for the antennas <NUM>.

At block <NUM>, the user equipment receives a configuration of time-frequency resources for Non-Orthogonal Multiple Access (NOMA) transmissions from the base station. For example, the user equipment <NUM> receives a configuration of time-frequency resources for Non-Orthogonal Multiple Access (NOMA) transmission from the base station <NUM>.

At block <NUM>, the user equipment receives an association between the downlink reference signals and the time-frequency resources from the base station. For example, the user equipment <NUM> receives an association between the downlink reference signals and the time-frequency resources from the base station <NUM>.

At block <NUM>, the user equipment transmits uplink data to the base station on one of the time-frequency resources using a transmit antenna configuration. The transmit antenna configuration is determined based upon a measurement of one or more receive beams by the user equipment or is determined based on an indication from the base station that is based on an uplink measurement, by the base station, of one or more transmit beams of the user equipment. For example, the user equipment <NUM> transmits uplink data to the base station on one of the time-frequency resources using a transmit antenna configuration for the antennas <NUM>.

The methods of <FIG> and <FIG> may allow the determination of optimized antenna configurations in a simple manner.

Claim 1:
A method for configuring beamformed wireless communication between a base station (<NUM>, <NUM>, <NUM>) and a user equipment (<NUM>), the method comprising:
transmitting (<NUM>), by the base station and using multiple transmit antenna configurations, downlink reference signals to the user equipment;
configuring (<NUM>), by the base station, time-frequency resources for Non-Orthogonal Multiple Access, NOMA, transmissions for the user equipment;
configuring (<NUM>) an association between the downlink reference signals and the time-frequency resources for the user equipment;
transmitting (<NUM>), to the user equipment, the configuration of the time-frequency resources for the NOMA transmissions and the association between the downlink reference signals and the time-frequency resources; and
receiving (<NUM>) uplink data from the user equipment on one of the time-frequency resources using a receive antenna configuration, the receive antenna configuration being determined at least in part using one of the multiple transmit antenna configurations used for transmitting one of the downlink reference signals associated with one of the time-frequency resources as indicated in the association.