Patent Publication Number: US-2023155693-A1

Title: Adaptation of transmit and receive antennas

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a divisional of U.S. application Ser. No. 17/174,324, filed Feb. 11, 2021, which in turns claims the benefit of U.S. Provisional Patent Application No. 62/980,086, filed Feb. 21, 2020, the contents of both of which are hereby incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The technology discussed below relates generally to wireless communication systems, and more particularly, to a time-period-based antenna adaptation for wireless communication. 
     INTRODUCTION 
     In a fifth generation (5G) new radio (NR) access network, bandwidth part (BWP) uplink (UL) layer adaptation may be used to achieve different number of layers in different BWPs. For example, during a period of relatively-high data rate transmission, a user equipment (UE) may be switched to a larger BWP with more layers. But such a relatively large BWP and layer usage consumes power. The UE may thus be switched to a smaller BWP with fewer layers during periods of relatively-low data rate transmission. In addition to BWP adaptation, a UE may be adapted to fallback from transmit (T) and receive (R) antenna configurations such as from two transmit antennas and four receive antennas (2T4R) to one transmit antenna and two receive antenna (1T2R). Although these adaptations save power, a UE may be subjected to substantial same-link interference or cross-link interference during downlink (DL) reception. Improved UE adaptations are thus needed to combat such interferences. 
     SUMMARY 
     The following presents a simplified summary of one or more aspects of the present disclosure, in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated features of the disclosure and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in a simplified form as a prelude to the more detailed description that is presented later. 
     In accordance with a first aspect of the disclosure, a method of wireless communication for a node is provided that includes: receiving an antenna adaptation command at the node; determining a combination of at least one transmit antenna and at least one receive antenna from a plurality of antenna combinations responsive to the antenna adaptation command, wherein the antenna adaptation command is valid for an antenna adaptation period; and communicating at the node using the determined combination of the at least one transmit antenna and the at least one receive antenna. 
     In accordance with a second aspect of the disclosure, a method of wireless communication for a node is provided that includes: during a first antenna adaptation period, transmitting from the node over a transmit set of transmit antennas according to a first data rate and receiving at the node over a receive set of antennas; selecting a subset of the transmit antennas in the transmit set responsive to an antenna adaptation command; and during a second antenna adaptation period, transmitting from the node over the subset of transmit antennas according to a second data rate that is lower than the first data rate. 
     In accordance with a third aspect of the disclosure, a communication node is provided that includes: a set of antennas; a processor configured to process a first antenna adaptation command that is valid for a first antenna adaptation period to determine a first subset of transmit antennas from the set of antennas and to determine a first subset of receive antennas from the set of antennas; and a transceiver configured to communicate using the first subset of transmit antennas and the first subset of receive antennas during the first antenna adaptation period. 
     In accordance with a fourth aspect of the disclosure, a wireless communication method for a base station is provided that includes: commanding a user equipment to use a first transmit and receive antenna selection during a first antenna adaptation period; and commanding the user equipment to use a second transmit and receive antenna selection during a second antenna adaptation period to reduce an interference at the user equipment during the second antenna adaptation period. 
     These and other aspects of the disclosure will become more fully understood upon a review of the detailed description, which follows. Other aspects, features, and embodiments of the present invention will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary embodiments of the present invention in conjunction with the accompanying figures. While features of the present invention may be discussed relative to certain embodiments and figures below, all embodiments of the present invention can include one or more of the advantageous features discussed herein. In other words, while one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various embodiments of the invention discussed herein. In similar fashion, while exemplary embodiments may be discussed below as device, system, or method embodiments it should be understood that such exemplary embodiments can be implemented in various devices, systems, and methods. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic illustration of a wireless communication system. 
         FIG.  2    is a conceptual illustration of an example of a radio access network. 
         FIG.  3    is a block diagram illustrating a wireless communication system supporting multiple-input multiple-output (MIMO) communication. 
         FIG.  4    is a schematic illustration of an organization of wireless resources in an air interface utilizing orthogonal frequency divisional multiplexing (OFDM). 
         FIG.  5    is a block diagram illustrating an example of a hardware implementation for a scheduled entity employing a processing system in accordance with aspects disclosed herein. 
         FIG.  6    is a flow chart illustrating an exemplary antenna adaptation process that facilitates some aspects of the disclosure. 
         FIG.  7    is a block diagram illustrating an example of a hardware implementation for a scheduling entity employing a processing system in accordance with aspects disclosed herein. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts. 
     While aspects and embodiments are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, packaging arrangements. For example, embodiments and/or uses may come about via integrated chip embodiments and other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, AI-enabled devices, etc.). While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or OEM devices or systems incorporating one or more aspects of the described innovations. In some practical settings, devices incorporating described aspects and features may also necessarily include additional components and features for implementation and practice of claimed and described embodiments. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes (e.g., hardware components including antenna, RF-chains, power amplifiers, modulators, buffer, processor(s), interleaver, adders/summers, etc.). It is intended that innovations described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc. of varying sizes, shapes and constitution. 
     Definitions 
     RAT: radio access technology. The type of technology or communication standard utilized for radio access and communication over a wireless air interface. Just a few examples of RATs include GSM, UTRA, E-UTRA (LTE), Bluetooth, and Wi-Fi. 
     NR: new radio. Generally refers to 5G technologies and the new radio access technology undergoing definition and standardization by 3GPP in Release 15. 
     Beamforming: directional signal transmission or reception. For a beamformed transmission, the amplitude and phase of each antenna in an array of antennas may be precoded, or controlled to create a desired (e.g., directional) pattern of constructive and destructive interference in the wave front. 
     MIMO: multiple-input multiple-output. MIMO is a multi-antenna technology that exploits multipath signal propagation so that the information-carrying capacity of a wireless link can be multiplied by using multiple antennas at the transmitter and receiver to send multiple simultaneous streams. At the multi-antenna transmitter, a suitable precoding algorithm (scaling the respective streams&#39; amplitude and phase) is applied (in some examples, based on known channel state information). At the multi-antenna receiver, the different spatial signatures of the respective streams (and, in some examples, known channel state information) can enable the separation of these streams from one another.
         1. In single-user MIMO, the transmitter sends one or more streams to the same receiver, taking advantage of capacity gains associated with using multiple Tx, Rx antennas in rich scattering environments where channel variations can be tracked.   2. The receiver may track these channel variations and provide corresponding feedback to the transmitter. This feedback may include channel quality information (CQI), the number of preferred data streams (e.g., rate control, a rank indicator (RI)), and a precoding matrix index (PMI).       

     Massive MIMO: a MIMO system with a very large number of antennas (e.g., greater than an 8×8 array). 
     MU-MIMO: a multi-antenna technology where base station, in communication with a large number of UEs, can exploit multipath signal propagation to increase overall network capacity by increasing throughput and spectral efficiency, and reducing the required transmission energy.
         3. The transmitter may attempt to increase the capacity by transmitting to multiple users using its multiple transmit antennas at the same time, and also using the same allocated time—frequency resources. The receiver may transmit feedback including a quantized version of the channel so that the transmitter can schedule the receivers with good channel separation. The transmitted data is precoded to maximize throughput for users and minimize inter-user interference.       

     DCI: downlink control indicator. A set of information transmitted at the L1 Layer that, among other things, schedules the downlink data channel (e.g., PDSCH) or the uplink data channel (e.g., PUSCH). 
     MAC-CE: media access control-control element. A MAC structure used for carrying MAC layer control information between a gNB and a UE. The structure may be implemented as a special bit string in a logical channel ID (LCD) field of a MAC Header. 
     The various concepts presented throughout this disclosure may be implemented across a broad variety of telecommunication systems, network architectures, and communication standards. Referring now to  FIG.  1   , as an illustrative example without limitation, various aspects of the present disclosure are illustrated with reference to a wireless communication system  100 . The wireless communication system  100  includes three interacting domains: a core network  102 , a radio access network (RAN)  104 , and a user equipment (UE)  106 . By virtue of the wireless communication system  100 , the UE  106  may be enabled to carry out data communication with an external data network  110 , such as (but not limited to) the Internet. 
     The RAN  104  may implement any suitable wireless communication technology or technologies to provide radio access to the UE  106 . As one example, the RAN  104  may operate according to 3 rd  Generation Partnership Project (3GPP) New Radio (NR) specifications, often referred to as 5G. As another example, the RAN  104  may operate under a hybrid of 5G NR and Evolved Universal Terrestrial Radio Access Network (eUTRAN) standards, often referred to as LTE. The 3GPP refers to this hybrid RAN as a next-generation RAN, or NG-RAN. Of course, many other examples may be utilized within the scope of the present disclosure. 
     As illustrated, the RAN  104  includes a plurality of base stations  108 . 
     Broadly, a base station is a network element in a radio access network responsible for radio transmission and reception in one or more cells to or from a UE. In different technologies, standards, or contexts, a base station may variously be referred to by those skilled in the art as a base transceiver station (BTS), a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), an access point (AP), a Node B (NB), an eNode B (eNB), a gNode B (gNB), or some other suitable terminology. 
     The radio access network  104  is further illustrated supporting wireless communication for multiple mobile apparatuses. A mobile apparatus may be referred to as user equipment (UE) in 3GPP standards, but may also be referred to by those skilled in the art as a mobile station (MS), a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT), a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. A UE may be an apparatus that provides a user with access to network services. 
     Within the present document, a “mobile” apparatus need not necessarily have a capability to move, and may be stationary. The term mobile apparatus or mobile device broadly refers to a diverse array of devices and technologies. UEs may include a number of hardware structural components sized, shaped, and arranged to help in communication; such components can include antennas, antenna arrays, RF chains, amplifiers, one or more processors, etc. electrically coupled to each other. For example, some non-limiting examples of a mobile apparatus include a mobile, a cellular (cell) phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal computer (PC), a notebook, a netbook, a smartbook, a tablet, a personal digital assistant (PDA), and a broad array of embedded systems, e.g., corresponding to an “Internet of things” (IoT). A mobile apparatus may additionally be an automotive or other transportation vehicle, a remote sensor or actuator, a robot or robotics device, a satellite radio, a global positioning system (GPS) device, an object tracking device, a drone, a multi-copter, a quad-copter, a remote control device, a consumer and/or wearable device, such as eyewear, a wearable camera, a virtual reality device, a smart watch, a health or fitness tracker, a digital audio player (e.g., MP3 player), a camera, a game console, etc. A mobile apparatus may additionally be a digital home or smart home device such as a home audio, video, and/or multimedia device, an appliance, a vending machine, intelligent lighting, a home security system, a smart meter, etc. A mobile apparatus may additionally be a smart energy device, a security device, a solar panel or solar array, a municipal infrastructure device controlling electric power (e.g., a smart grid), lighting, water, etc.; an industrial automation and enterprise device; a logistics controller; agricultural equipment; military defense equipment, vehicles, aircraft, ships, and weaponry, etc. Still further, a mobile apparatus may provide for connected medicine or telemedicine support, e.g., health care at a distance. Telehealth devices may include telehealth monitoring devices and telehealth administration devices, whose communication may be given preferential treatment or prioritized access over other types of information, e.g., in terms of prioritized access for transport of critical service data, and/or relevant QoS for transport of critical service data. 
     Wireless communication between a RAN  104  and a UE  106  may be described as utilizing an air interface. Transmissions over the air interface from a base station (e.g., base station  108 ) to one or more UEs (e.g., UE  106 ) may be referred to as downlink (DL) transmission. In accordance with certain aspects of the present disclosure, the term downlink may refer to a point-to-multipoint transmission originating at a scheduling entity (described further below; e.g., base station  108 ). Another way to describe this scheme may be to use the term broadcast channel multiplexing. Transmissions from a UE (e.g., UE  106 ) to a base station (e.g., base station  108 ) may be referred to as uplink (UL) transmissions. In accordance with further aspects of the present disclosure, the term uplink may refer to a point-to-point transmission originating at a scheduled entity (described further below; e.g., UE  106 ). 
     In some examples, access to the air interface may be scheduled, wherein a scheduling entity (e.g., a base station  108 ) allocates resources for communication among some or all devices and equipment within its service area or cell. Within the present disclosure, as discussed further below, the scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more scheduled entities. That is, for scheduled communication, UEs  106 , which may be scheduled entities, may utilize resources allocated by the scheduling entity  108 . 
     Base stations  108  are not the only entities that may function as scheduling entities. That is, in some examples, a UE may function as a scheduling entity, scheduling resources for one or more scheduled entities (e.g., one or more other UEs). 
     As illustrated in  FIG.  1   , a scheduling entity  108  may broadcast downlink traffic  112  to one or more scheduled entities  106 . Broadly, the scheduling entity  108  is a node or device responsible for scheduling traffic in a wireless communication network, including the downlink traffic  112  and, in some examples, uplink traffic  116  from one or more scheduled entities  106  to the scheduling entity  108 . On the other hand, the scheduled entity  106  is a node or device that receives downlink control information  114 , including but not limited to scheduling information (e.g., a grant), synchronization or timing information, or other control information from another entity in the wireless communication network such as the scheduling entity  108 . 
     In general, base stations  108  may include a backhaul interface for communication with a backhaul portion  120  of the wireless communication system. The backhaul  120  may provide a link between a base station  108  and the core network  102 . Further, in some examples, a backhaul network may provide interconnection between the respective base stations  108 . Various types of backhaul interfaces may be employed, such as a direct physical connection, a virtual network, or the like using any suitable transport network. 
     The core network  102  may be a part of the wireless communication system  100 , and may be independent of the radio access technology used in the RAN  104 . In some examples, the core network  102  may be configured according to 5G standards (e.g., 5GC). In other examples, the core network  102  may be configured according to a 4G evolved packet core (EPC), or any other suitable standard or configuration. 
     Referring now to  FIG.  2   , by way of example and without limitation, a schematic illustration of a RAN  200  is provided. In some examples, the RAN  200  may be the same as the RAN  104  described above and illustrated in  FIG.  1   . The geographic area covered by the RAN  200  may be divided into cellular regions (cells) that can be uniquely identified by a user equipment (UE) based on an identification broadcasted from one access point or base station.  FIG.  2    illustrates macrocells  202 ,  204 , and  206 , and a small cell  208 , each of which may include one or more sectors (not shown). A sector is a sub-area of a cell. All sectors within one cell are served by the same base station. A radio link within a sector can be identified by a single logical identification belonging to that sector. In a cell that is divided into sectors, the multiple sectors within a cell can be formed by groups of antennas with each antenna responsible for communication with UEs in a portion of the cell. 
     In  FIG.  2   , two base stations  210  and  212  are shown in cells  202  and  204 ; and a third base station  214  is shown controlling a remote radio head (RRH)  216  in cell  206 . That is, a base station can have an integrated antenna or can be connected to an antenna or RRH by feeder cables. In the illustrated example, the cells  202 ,  204 , and  126  may be referred to as macrocells, as the base stations  210 ,  212 , and  214  support cells having a large size. Further, a base station  218  is shown in the small cell  208  (e.g., a microcell, picocell, femtocell, home base station, home Node B, home eNode B, etc.) which may overlap with one or more macrocells. In this example, the cell  208  may be referred to as a small cell, as the base station  218  supports a cell having a relatively small size. Cell sizing can be done according to system design as well as component constraints. 
     It is to be understood that the radio access network  200  may include any number of wireless base stations and cells. Further, a relay node may be deployed to extend the size or coverage area of a given cell. The base stations  210 ,  212 ,  214 ,  218  provide wireless access points to a core network for any number of mobile apparatuses. In some examples, the base stations  210 ,  212 ,  214 , and/or  218  may be the same as the base station/scheduling entity  108  described above and illustrated in  FIG.  1   . 
       FIG.  2    further includes a quadcopter or drone  220 , which may be configured to function as a base station. That is, in some examples, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile base station such as the quadcopter  220 . 
     Within the RAN  200 , the cells may include UEs that may be in communication with one or more sectors of each cell. Further, each base station  210 ,  212 ,  214 ,  218 , and  220  may be configured to provide an access point to a core network  102  (see  FIG.  1   ) for all the UEs in the respective cells. For example, UEs  222  and  224  may be in communication with base station  210 ; UEs  226  and  228  may be in communication with base station  212 ; UEs  230  and  232  may be in communication with base station  214  by way of RRH  216 ; UE  234  may be in communication with base station  218 ; and UE  236  may be in communication with mobile base station  220 . In some examples, the UEs  222 ,  224 ,  226 ,  228 ,  230 ,  232 ,  234 ,  236 ,  238 ,  240 , and/or  242  may be the same as the UE/scheduled entity  106  described above and illustrated in  FIG.  1   . 
     In some examples, a mobile network node (e.g., quadcopter  220 ) may be configured to function as a UE. For example, the quadcopter  220  may operate within cell  202  by communicating with base station  210 . 
     In a further aspect of the RAN  200 , sidelink signals may be used between UEs without necessarily relying on scheduling or control information from a base station. For example, two or more UEs (e.g., UEs  226  and  228 ) may communicate with each other using peer to peer (P2P) or sidelink signals  227  without relaying that communication through a base station (e.g., base station  212 ). In a further example, UE  238  is illustrated communicating with UEs  240  and  242 . Here, the UE  238  may function as a scheduling entity or a primary sidelink device, and UEs  240  and  242  may function as a scheduled entity or a non-primary (e.g., secondary) sidelink device. In still another example, a UE may function as a scheduling entity in a device-to-device (D2D), peer-to-peer (P2P), or vehicle-to-vehicle (V2V) network, and/or in a mesh network. In a mesh network example, UEs  240  and  242  may optionally communicate directly with one another in addition to communicating with the scheduling entity  238 . Thus, in a wireless communication system with scheduled access to time—frequency resources and having a cellular configuration, a P2P configuration, or a mesh configuration, a scheduling entity and one or more scheduled entities may communicate utilizing the scheduled resources. 
     In the radio access network  200 , the ability for a UE to communicate while moving, independent of its location, is referred to as mobility. The various physical channels between the UE and the radio access network are generally set up, maintained, and released under the control of an access and mobility management function (AMF, not illustrated, part of the core network  102  in  FIG.  1   ), which may include a security context management function (SCMF) that manages the security context for both the control plane and the user plane functionality, and a security anchor function (SEAF) that performs authentication. 
     In various aspects of the disclosure, a radio access network  200  may utilize DL-based mobility or UL-based mobility to enable mobility and handovers (i.e., the transfer of a UE&#39;s connection from one radio channel to another). In a network configured for DL-based mobility, during a call with a scheduling entity, or at any other time, a UE may monitor various parameters of the signal from its serving cell as well as various parameters of neighboring cells. Depending on the quality of these parameters, the UE may maintain communication with one or more of the neighboring cells. During this time, if the UE moves from one cell to another, or if signal quality from a neighboring cell exceeds that from the serving cell for a given amount of time, the UE may undertake a handoff or handover from the serving cell to the neighboring (target) cell. For example, UE  224  (illustrated as a vehicle, although any suitable form of UE may be used) may move from the geographic area corresponding to its serving cell  202  to the geographic area corresponding to a neighbor cell  206 . When the signal strength or quality from the neighbor cell  206  exceeds that of its serving cell  202  for a given amount of time, the UE  224  may transmit a reporting message to its serving base station  210  indicating this condition. In response, the UE  224  may receive a handover command, and the UE may undergo a handover to the cell  206 . 
     In a network configured for UL-based mobility, UL reference signals from each UE may be utilized by the network to select a serving cell for each UE. In some examples, the base stations  210 ,  212 , and  214 / 216  may broadcast unified synchronization signals (e.g., unified Primary Synchronization Signals (PSSs), unified Secondary Synchronization Signals (SSSs) and unified Physical Broadcast Channels (PBCH)). The UEs  222 ,  224 ,  226 ,  228 ,  230 , and  232  may receive the unified synchronization signals, derive the carrier frequency and slot timing from the synchronization signals, and in response to deriving timing, transmit an uplink pilot or reference signal. The uplink pilot signal transmitted by a UE (e.g., UE  224 ) may be concurrently received by two or more cells (e.g., base stations  210  and  214 / 216 ) within the radio access network  200 . Each of the cells may measure a strength of the pilot signal, and the radio access network (e.g., one or more of the base stations  210  and  214 / 216  and/or a central node within the core network) may determine a serving cell for the UE  224 . As the UE  224  moves through the radio access network  200 , the network may continue to monitor the uplink pilot signal transmitted by the UE  224 . When the signal strength or quality of the pilot signal measured by a neighboring cell exceeds that of the signal strength or quality measured by the serving cell, the network  200  may handover the UE  224  from the serving cell to the neighboring cell, with or without informing the UE  224 . 
     Although the synchronization signal transmitted by the base stations  210 ,  212 , and  214 / 216  may be unified, the synchronization signal may not identify a particular cell, but rather may identify a zone of multiple cells operating on the same frequency and/or with the same timing. The use of zones in 5G networks or other next generation communication networks enables the uplink-based mobility framework and improves the efficiency of both the UE and the network, since the number of mobility messages that need to be exchanged between the UE and the network may be reduced. 
     In various implementations, the air interface in the radio access network  200  may utilize licensed spectrum, unlicensed spectrum, or shared spectrum. Licensed spectrum provides for exclusive use of a portion of the spectrum, generally by virtue of a mobile network operator purchasing a license from a government regulatory body. Unlicensed spectrum provides for shared use of a portion of the spectrum without need for a government-granted license. While compliance with some technical rules is generally still required to access unlicensed spectrum, generally, any operator or device may gain access. Shared spectrum may fall between licensed and unlicensed spectrum, wherein technical rules or limitations may be required to access the spectrum, but the spectrum may still be shared by multiple operators and/or multiple RATs. For example, the holder of a license for a portion of licensed spectrum may provide licensed shared access (LSA) to share that spectrum with other parties, e.g., with suitable licensee-determined conditions to gain access. 
     The air interface in the radio access network  200  may utilize one or more duplexing algorithms. Duplex refers to a point-to-point communication link where both endpoints can communicate with one another in both directions. Full duplex means both endpoints can simultaneously communicate with one another. Half duplex means only one endpoint can send information to the other at a time. In a wireless link, a full duplex channel generally relies on physical isolation of a transmitter and receiver, and suitable interference cancellation technologies. Full duplex emulation is frequently implemented for wireless links by utilizing frequency division duplex (FDD) or time division duplex (TDD). In FDD, transmissions in different directions operate at different carrier frequencies. In TDD, transmissions in different directions on a given channel are separated from one another using time division multiplexing. That is, at some times the channel is dedicated for transmissions in one direction, while at other times the channel is dedicated for transmissions in the other direction, where the direction may change very rapidly, e.g., several times per slot. 
     In some aspects of the disclosure, the scheduling entity and/or scheduled entity may be configured for beamforming and/or multiple-input multiple-output (MIMO) technology.  FIG.  3    illustrates an example of a wireless communication system  300  supporting MIMO. In a MIMO system, a transmitter  302  includes multiple transmit antennas  304  (e.g., N transmit antennas) and a receiver  306  includes multiple receive antennas  308  (e.g., M receive antennas). Thus, there are N×M signal paths  310  from the transmit antennas  304  to the receive antennas  308 . Each of the transmitter  302  and the receiver  306  may be implemented, for example, within a scheduling entity  108 , a scheduled entity  106 , or any other suitable wireless communication device. 
     The use of such multiple antenna technology enables the wireless communication system to exploit the spatial domain to support spatial multiplexing, beamforming, and transmit diversity. Spatial multiplexing may be used to transmit different streams of data, also referred to as layers, simultaneously on the same time-frequency resource. The data streams may be transmitted to a single UE to increase the data rate or to multiple UEs to increase the overall system capacity, the latter being referred to as multi-user MIMO (MU-MIMO). This is achieved by spatially precoding each data stream (i.e., multiplying the data streams with different weighting and phase shifting) and then transmitting each spatially precoded stream through multiple transmit antennas on the downlink. The spatially precoded data streams arrive at the UE(s) with different spatial signatures, which enables each of the UE(s) to recover the one or more data streams destined for that UE. On the uplink, each UE transmits a spatially precoded data stream, which enables the base station to identify the source of each spatially precoded data stream. 
     The number of data streams or layers corresponds to the rank of the transmission. In general, the rank of the MIMO system  300  is limited by the number of transmit or receive antennas  304  or  308 , whichever is lower. In addition, the channel conditions at the UE, as well as other considerations, such as the available resources at the base station, may also affect the transmission rank. For example, the rank (and therefore, the number of data streams) assigned to a particular UE on the downlink may be determined based on the rank indicator (RI) transmitted from the UE to the base station. The RI may be determined based on the antenna configuration (e.g., the number of transmit and receive antennas) and a measured signal-to-interference-and-noise ratio (SINR) on each of the receive antennas. The RI may indicate, for example, the number of layers that may be supported under the current channel conditions. The base station may use the RI, along with resource information (e.g., the available resources and amount of data to be scheduled for the UE), to assign a transmission rank to the UE. 
     In Time Division Duplex (TDD) systems, the UL and DL are reciprocal, in that each uses different time slots of the same frequency bandwidth. Therefore, in TDD systems, the base station may assign the rank for DL MIMO transmissions based on UL SINR measurements (e.g., based on a Sounding Reference Signal (SRS) transmitted from the UE or other pilot signal). Based on the assigned rank, the base station may then transmit the CSI-RS with separate C-RS sequences for each layer to provide for multi-layer channel estimation. From the CSI-RS, the UE may measure the channel quality across layers and resource blocks and feedback the CQI and RI values to the base station for use in updating the rank and assigning REs for future downlink transmissions. 
     In the simplest case, as shown in  FIG.  3   , a rank-2 spatial multiplexing transmission on a 2×2 MIMO antenna configuration will transmit one data stream from each transmit antenna  304 . Each data stream reaches each receive antenna  308  along a different signal path  310 . The receiver  306  may then reconstruct the data streams using the received signals from each receive antenna  308 . 
     The air interface in the radio access network  200  may utilize one or more multiplexing and multiple access algorithms to enable simultaneous communication of the various devices. For example, 5G NR specifications provide multiple access for UL transmissions from UEs  222  and  224  to base station  210 , and for multiplexing for DL transmissions from base station  210  to one or more UEs  222  and  224 , utilizing orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP). In addition, for UL transmissions, 5G NR specifications provide support for discrete Fourier transform-spread-OFDM (DFT-s-OFDM) with a CP (also referred to as single-carrier FDMA (SC-FDMA)). However, within the scope of the present disclosure, multiplexing and multiple access are not limited to the above schemes, and may be provided utilizing time division multiple access (TDMA), code division multiple access (CDMA), frequency division multiple access (FDMA), sparse code multiple access (SCMA), resource spread multiple access (RSMA), or other suitable multiple access schemes. Further, multiplexing DL transmissions from the base station  210  to UEs  222  and  224  may be provided utilizing time division multiplexing (TDM), code division multiplexing (CDM), frequency division multiplexing (FDM), orthogonal frequency division multiplexing (OFDM), sparse code multiplexing (SCM), or other suitable multiplexing schemes. 
     Various aspects of the present disclosure will be described with reference to an OFDM waveform, schematically illustrated in  FIG.  4   . It should be understood by those of ordinary skill in the art that the various aspects of the present disclosure may be applied to a DFT-s-OFDMA waveform in substantially the same way as described herein below. That is, while some examples of the present disclosure may focus on an OFDM link for clarity, it should be understood that the same principles may be applied as well to DFT-s-OFDMA waveforms. 
     Within the present disclosure, a frame refers to a duration of 10 ms for wireless transmissions, with each frame consisting of 10 subframes of 1 ms each. On a given carrier, there may be one set of frames in the UL, and another set of frames in the DL. An expanded view of an exemplary DL subframe  402  is also illustrated in  FIG.  4   , showing an OFDM resource grid  404 . However, as those skilled in the art will readily appreciate, the PHY transmission structure for any particular application may vary from the example described here, depending on any number of factors. Here, time is in the horizontal direction with units of OFDM symbols; and frequency is in the vertical direction with units of subcarriers or tones. 
     The resource grid  404  may be used to schematically represent time— frequency resources for a given antenna port. That is, in a MIMO implementation with multiple antenna ports available, a corresponding multiple number of resource grids  404  may be available for communication. The resource grid  404  is divided into multiple resource elements (REs)  406 . An RE, which is 1 subcarrier×1 symbol, is the smallest discrete part of the time—frequency grid, and contains a single complex value representing data from a physical channel or signal. Depending on the modulation utilized in a particular implementation, each RE may represent one or more bits of information. In some examples, a block of REs may be referred to as a physical resource block (PRB) or more simply a resource block (RB)  408 , which contains any suitable number of consecutive subcarriers in the frequency domain. In one example, an RB may include 12 subcarriers, a number independent of the numerology used. In some examples, depending on the numerology, an RB may include any suitable number of consecutive OFDM symbols in the time domain. Within the present disclosure, it is assumed that a single RB such as the RB  408  entirely corresponds to a single direction of communication (either transmission or reception for a given device). A set of contiguous RBs  408  such as shown for resource grid  404  form a bandwidth part (BWP). 
     A UE generally utilizes only a subset of the resource grid  404 . An RB may be the smallest unit of resources that can be allocated to a UE. Thus, the more RBs scheduled for a UE, and the higher the modulation scheme chosen for the air interface, the higher the data rate for the UE. 
     In this illustration, the RB  408  is shown as occupying less than the entire bandwidth of the subframe  402 , with some subcarriers illustrated above and below the RB  408 . In a given implementation, the subframe  402  may have a bandwidth corresponding to any number of one or more RBs  408 . Further, in this illustration, the RB  408  is shown as occupying less than the entire duration of the subframe  402 , although this is merely one possible example. 
     Each 1 ms subframe  402  may consist of one or multiple adjacent slots. In the example shown in  FIG.  4   , one subframe  402  includes four slots  410 , as an illustrative example. In some examples, a slot may be defined according to a specified number of OFDM symbols with a given cyclic prefix (CP) length. For example, a slot may include 7 or 14 OFDM symbols with a nominal CP. Additional examples may include mini-slots having a shorter duration (e.g., one or two OFDM symbols). These mini-slots may in some cases be transmitted occupying resources scheduled for ongoing slot transmissions for the same or for different UEs. 
     An expanded view of one of the slots  410  illustrates the slot  410  including a control region  412  and a data region  414 . In general, the control region  412  may carry control channels (e.g., PDCCH), and the data region  414  may carry data channels (e.g., PDSCH or PUSCH). Of course, a slot may contain all DL, all UL, or at least one DL portion and at least one UL portion. The simple structure illustrated in  FIG.  4    is merely exemplary in nature, and different slot structures may be utilized, and may include one or more of each of the control region(s) and data region(s). 
     Although not illustrated in  FIG.  4   , the various REs  406  within a RB  408  may be scheduled to carry one or more physical channels, including control channels, shared channels, data channels, etc. Other REs  406  within the RB  408  may also carry pilots or reference signals, including but not limited to a demodulation reference signal (DMRS) a control reference signal (CRS), or a sounding reference signal (SRS). These pilots or reference signals may provide for a receiving device to perform channel estimation of the corresponding channel, which may enable coherent demodulation/detection of the control and/or data channels within the RB  408 . 
     In a DL transmission, the transmitting device (e.g., the scheduling entity  108 ) may allocate one or more REs  406  (e.g., within a control region  412 ) to carry DL control information  114  including one or more DL control channels, such as a PBCH; a PSS; a SSS; a physical control format indicator channel (PCFICH); a physical hybrid automatic repeat request (HARQ) indicator channel (PHICH); and/or a physical downlink control channel (PDCCH), etc., to one or more scheduled entities  106 . The PCFICH provides information to assist a receiving device in receiving and decoding the PDCCH. The PDCCH carries downlink control information (DCI) including but not limited to power control commands, scheduling information, a grant, and/or an assignment of REs for DL and UL transmissions. The PHICH carries HARQ feedback transmissions such as an acknowledgment (ACK) or negative acknowledgment (NACK). HARQ is a technique well-known to those of ordinary skill in the art, wherein the integrity of packet transmissions may be checked at the receiving side for accuracy, e.g., utilizing any suitable integrity checking mechanism, such as a checksum or a cyclic redundancy check (CRC). If the integrity of the transmission confirmed, an ACK may be transmitted, whereas if not confirmed, a NACK may be transmitted. In response to a NACK, the transmitting device may send a HARQ retransmission, which may implement chase combining, incremental redundancy, etc. 
     In an UL transmission, the transmitting device (e.g., the scheduled entity  106 ) may utilize one or more REs  406  to carry UL control information  118  including one or more UL control channels, such as a physical uplink control channel (PUCCH), to the scheduling entity  108 . UL control information may include a variety of packet types and categories, including pilots, reference signals, and information configured to enable or assist in decoding uplink data transmissions. In some examples, the control information  118  may include a scheduling request (SR), e.g., a request for the scheduling entity  108  to schedule uplink transmissions. Here, in response to the SR transmitted on the control channel, the scheduling entity  108  may transmit downlink control information  114  that may schedule resources for uplink packet transmissions. UL control information may also include HARQ feedback, channel state feedback (CSF), or any other suitable UL control information. 
     In addition to control information, one or more REs  406  (e.g., within the data region  414 ) may be allocated for user data or traffic data. Such traffic may be carried on one or more traffic channels, such as, for a DL transmission, a physical downlink shared channel (PDSCH); or for an UL transmission, a physical uplink shared channel (PUSCH). In some examples, one or more REs  406  within the data region  414  may be configured to carry system information blocks (SIBs), carrying information that may enable access to a given cell. 
     The channels or carriers described above and illustrated in  FIGS.  1  and  4    are not necessarily all the channels or carriers that may be utilized between a scheduling entity  108  and scheduled entities  106 , and those of ordinary skill in the art will recognize that other channels or carriers may be utilized in addition to those illustrated, such as other traffic, control, and feedback channels. 
     These physical channels described above are generally multiplexed and mapped to transport channels for handling at the medium access control (MAC) layer. Transport channels carry blocks of information called transport blocks (TB). The transport block size (TB S), which may correspond to a number of bits of information, may be a controlled parameter, based on the modulation and coding scheme (MCS) and the number of RBs in a given transmission. 
     Exemplary Implementations 
     As previously noted, interference such as same-link interference and cross-link interference remain as impediments to DL reception for a UE. Same-link interference refers to interference stemming from other UEs in the same cell (intra-cell) or from neighboring cells (inter-cell). Cross-link interference occurs during full-duplex operation in which the UE&#39;s transmit antennas and receive antennas operate simultaneously (same-cell). Inter-cell cross-link interference may occur to a UE operating on a carrier frequency if transmission occurs in neighboring cells in different UL/DL slot configurations but on the same carrier or neighboring carriers. 
     To combat these sources of interference, it is useful for a communication node (e.g., a UE) to use a relatively-smaller number of transmit antennas for UL and a relatively-larger number of receive antennas for DL. But note that the sources of interference may be time dependent. For example, referring again to  FIG.  4   , the UL and DL traffic may change from one sub-frame  402  to another sub-frame  402 . Alternatively, this traffic may change on a slot  410  to another slot  410  basis. Indeed, the sources of interference may change on a sub-slot (mini time slot) basis. A scheduling entity such as any of base stations  210 ,  212 ,  214 ,  218  of  FIG.  2    as disclosed herein may adapt the number of transmit antennas to be used for UL as well as the number of receive antennas to be used for DL. This adaptation is responsive to an antenna adaptation command that is valid for an antenna adaptation period. Depending upon the implementation, the antenna adaptation period may be a time slot, a portion of a time slot such as a mini slot, a plurality of time slots, or a bandwidth part switching period. 
     Note that the UE itself (or a neighboring UE) may be the scheduling entity in alternative implementations. In general, it will be assumed herein that the UE possesses a plurality of antennas (e.g., 2, 4, or more) for such scheduling. In a TDD implementation, the plurality of antennas may be shared for both transmit and receive. In a full-duplex implementation, there may instead be a set of transmit antennas and a distinct set of receive antennas. 
     Once a UE has begun to camp in the corresponding cell supported by a gNB, it may be assumed herein that the gNB is then informed of the number of transmit and receive antennas available to the UE so that the antenna selection may be based upon the UE&#39;s particular configuration. Similarly, the gNB is informed of the number of antenna ports as well as the RF chains available in the UE so that MIMO data streams (layers) may be adapted as well. In addition, the UE&#39;s antenna switching capability should also be considered. Dependent upon these factors, the antenna adaptation command controls the selection or determination of which transmit antennas will be used for UL during the antenna adaptation period. Similarly, the antenna adaptation command (or commands) controls which receive antennas will be used for DL during the antenna adaptation period. The antenna adaptation command may have a variety of implementations. In one implementation, the scheduling information discussed earlier for the DCI carried in the PDCCH may include one or more bits to form the antenna adaptation command that controls the antenna adaptations. For example, one DCI bit indication may control an adaptation between a single transmit antenna, two receive antenna (1T2R) configuration for the UE and a single transmit antenna, four receive antenna (1T4R) configuration for the UE. Alternatively, the antenna adaptation command may be based on at least one of the DCI format, the decoding candidate, and the DCI size. 
     In another implementation, the antenna adaptation command may be based upon at least one MAC-CE message. In yet another implementation, the antenna adaptation command may be an RRC-based command that is configured individually to the UE and is active during a time period such as corresponding to a bandwidth part switching period, to a time slot, or to a portion of a time slot such as a mini-slot. Note that all these examples of an adaptation command may be activation/deactivation based such that once the transmit and receive antenna assignment is fixed by the adaptation command it will be valid until de-activated or re-activated. The resulting activation may thus be indefinite or semi-persistent. Such an activation command may be formed using any combination of the preceding DCI, MAC CE, or RRC implementations. 
     Should a UE be implementing carrier aggregation, the antenna adaptation responsive to the antenna adaptation command may be the same as or differ across the various component carriers (CCs) included within the carrier aggregation. For example, the antenna adaptation for a first component carrier may be independent from or tied to the antenna adaptation for a second component carrier. Similarly, the antenna adaptation for a first component carrier may be controlled by an antenna adaptation command transmitted on a second component carrier. In addition, if the UE is subjected to fallback, the fallback may be managed separately or jointly for different antenna adaptation states. For example, operation in a 2T4R configuration or a 1T4R configuration may both fallback to a 1T2R configuration. Alternatively, operation in different antenna configurations may be subjected to different fallback states. 
     More generally, the antenna configuration responsive to an antenna adaptation command may be denoted as xTyR, where x represents the number of selected transmit (T) antennas and y represents the number of selected receive (R) antennas. Some example xTyR configurations include 1T2R, 1T4R, 2T4R, 4T4R, 1T8R, 2T8R, 4T8R, 8T8R, and so on. Such xTyR configurations are also denoted herein as antenna combinations as each xTyR configuration may be deemed to represent a particular combination of transmit and receive antennas. The antenna adaptation command thus identifies or determines a particular antenna combination for the communication node. The communication node may then proceed to communicate using the determined antenna combination (transmit using the selected transmit antennas and receive using the selected receive antennas). 
     The antenna adaptation may be based on the bandwidth part adaptation to offer a more refined management as compared to layer adaptation. For example, selection of a first antenna configuration such as 1T4R may be based on a first bandwidth part switching period (BWP1). The bandwidth part adaptation is thus linked to the antenna configuration in such an implementation. Similarly, selection of a second antenna configuration (e.g., 1T2R) may be based on operation in a second bandwidth part switching period (BWP2) whereas selection of a third antenna configuration (e.g., 2T4R) may be based on operation in a third bandwidth part switching period (BWP3), and so on. 
     The antenna adaptation as disclosed herein may also be exclusive such that a UE is instructed by the antenna adaptation command to exclude certain ones of coupled receive and transmit antennas. For example, a UE may be commanded to use only standalone (dedicated) receive antennas for reception and/or to use only standalone transmit antennas for transmission. 
     An example UE (scheduled entity)  500  is shown in  FIG.  5    that includes a processing system  514  for controlling the transmit and receive selections from a set  565  of antennas  560 . It is assumed herein that there are at least four antennas  560 . Processing system  514  includes a bus interface  508 , a bus  502 , memory  505 , a processor  504 , and a computer-readable medium  506 . Furthermore, UE  500  may include a user interface  512  and a transceiver  510 . 
     The processor  504  may include a receiving circuitry  50  configured for various functions, including, for example, to receive the antenna adaptation command. Examples of processors  504  include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. As illustrated, the processor  504  may also include antennae circuitry  542  configured for various functions. For instance, antennae circuitry  542  may be configured to configure at least four antennas  560  responsive to the antenna adaptation command. The processor  504  may further include transmitting circuitry  544  configured for various functions, including, for example, to transmit an antenna status indication regarding the number of antennas  560  for UE  500 . 
     Various other aspects for UE  500  are also contemplated. For instance, it is contemplated that the transmitting circuitry  544  may be configured to report to the network a UE capability. Such UE capability may, for example, encompass the capabilities of the at least four antennas  560 , which includes the capability of the UE  500  to support antenna selection. For example, UE  500  may have the capability to operate in a 1T4R configuration, a 1T2R configuration, and a 2T4R configuration as described previously. Other possible configurations include 1T1R (one transmit antenna and one receive antenna), 4T4R (four transmit antennas and four receive antennas), and 2T2R (two transmit antennas and four receive antennas). As noted earlier, the antenna configuration may be denoted as xTyR, where x represents the number of selected transmit antennas and y represents the number of selected receive antennas. It will be appreciated that x and y may be greater than four depending (e.g., eight or sixteen) depending upon the antenna array size for UE  500 . It will be further appreciated that transceiver  510  includes antenna switching circuits (not illustrated) for the selection of the active receive and transmit antennas. If the antenna adaptation is within a single bandwidth part switching period and is slot-dependent, the channel state information (CSI) feedback from UE  500  may be configured accordingly. For example, slot-dependent CSI may be designed assuming the corresponding xTyR antenna configuration. Transmission of an uplink sounding reference signal (SRS) may also be dependent on the antenna adaptation in some implementations. In addition, xTyR adaptation may be dependent on the type of transmissions from UE  500 . For example, some transmissions such as groupcast and broadcast transmissions, or unicast transmissions as scheduled by fallback downlink control information (DCI) may all use a particular or reference xTyR antenna configuration. In such implementations, the xTyR adaptation may only be possible for non-fallback DCI. 
     Processor  504  is also responsible for managing the bus  502  and general processing, including the execution of software stored on the computer-readable medium  506 . The software, when executed by the processor  504 , causes the processing system  514  to perform the various functions described below for any particular apparatus. The computer-readable medium  506  and the memory  505  may also be used for storing data that is manipulated by the processor  504  when executing software. 
     The bus  502  may include any number of interconnecting buses and bridges depending on the specific application of the processing system  514  and the overall design constraints. The bus  502  communicatively couples together various circuits including one or more processors (represented generally by the processor  504 ), the memory  505 , and computer-readable media (represented generally by the computer-readable medium  506 ). The bus  502  may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. The bus interface  508  provides an interface between the bus  502  and the transceiver  510 . The transceiver  510  provides a communication interface or means for communicating with various other apparatus over a transmission medium. Depending upon the nature of the apparatus, a user interface  512  (e.g., keypad, display, speaker, microphone, joystick) may also be provided. 
     One or more processors  504  in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The software may reside on the computer-readable medium  506 , which may be a non-transitory computer-readable medium. The computer-readable medium  506  may reside in the processing system  514 , external to the processing system  514 , or distributed across multiple entities including the processing system  514 . 
     In one or more examples, the computer-readable storage medium  506  may include receiving software  552  configured for various functions, including those performed by receiving circuitry  540 . Similarly, antennae software  554  may be configured with the instructions for antennae circuitry  542  and transmitting software  556  may be configured with the instructions for transmitting circuitry  544 . 
     In a particular configuration, it is also contemplated that the UE  500  includes means for receiving an antenna adaptation command and means for configuring antennas of the UE  500  based on the antenna adaptation command. In one aspect, the aforementioned means may be the processor(s)  504  configured to perform the functions recited by the aforementioned means. In another aspect, the aforementioned means may be a circuit or any apparatus configured to perform the functions recited by the aforementioned means. 
     Of course, in the above examples, the circuitry included in the processor  504  is merely provided as an example, and other means for carrying out the described functions may be included within various aspects of the present disclosure, including but not limited to the instructions stored in the computer-readable storage medium  506 , or any other suitable apparatus or means described herein, and utilizing, for example, the processes and/or algorithms described in relation to  FIG.  6   . In  FIG.  6   , a flow chart is provided, which illustrates an exemplary antenna adaptation process  600  for wireless communication at a node. In some examples, the node at which process  600  may be carried out may be the UE  500  illustrated in  FIG.  5   . In some examples, the node may be a base station such as discussed further with regard to  FIG.  7    below. 
     Process  600  begins with an act  605  of receiving an antenna adaptation command at the node. As noted earlier, the antenna adaptation command may be implemented in a variety of ways such as through a DCI message, a MAC CE, or an RLC-based message. The process  600  also includes an act  610  of determining a combination of at least one transmit antenna and at least one receive antenna from a plurality of antenna combinations responsive to the antenna adaptation command, wherein the antenna adaptation command is valid for an antenna adaptation period. The selection of x transmit antennas and y receive antennas for an xTyR antenna configuration is an example of act  610 . In addition, the process includes an act  615  of communicating at the node using the determined combination of the at least one transmit antenna and the at least one receive antenna. This communication may be either an uplink message or a downlink message and may also be either a user plane message or a control plane message. 
       FIG.  7    is a block diagram illustrating an example of a hardware implementation for a scheduling entity such as a base station  700  employing a processing system  714 . In alternative implementations, the scheduling entity may be another UE. Processing system  714  includes one or more processors  704 . Examples of processors  704  include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. In various examples, the base station  700  may be configured to perform any one or more of the functions described herein. 
     In this example, the processing system  714  may be implemented with a bus architecture, represented generally by the bus  702 . The bus  702  may include any number of interconnecting buses and bridges depending on the specific application of the processing system  714  and the overall design constraints. The bus  702  communicatively couples together various circuits including one or more processors (represented generally by the processor  704 ), a memory  705 , and computer-readable media (represented generally by the computer-readable medium  706 ). The bus  702  may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. A bus interface  708  provides an interface between the bus  702  and a transceiver  710 . The transceiver  710  provides a communication interface or means for communicating with various other apparatus over a transmission medium. Depending upon the nature of the apparatus, a user interface  712  (e.g., keypad, display, speaker, microphone, joystick) may also be provided. 
     In some aspects of the disclosure, the processor  704  may include a receiving circuitry  740  configured for various functions, including, for example, to receive an antenna configuration capability reported from a scheduled entity (e.g., UE  500 ), wherein the scheduled entity comprises at least four antennas. As illustrated, the processor  704  may also include a determination circuitry  742  configured for various functions. For instance, the determination circuitry  742  may be configured to perform an antenna selection determination based on the capability reporting and to generate a corresponding antenna adaptation command accordingly. An example antenna adaptation command may command for a xTyR antenna configuration in the scheduled entity (e.g., UE  500 ) 
     Referring back to the remaining components of base station  700 , it should be appreciated that the processor  704  is responsible for managing the bus  702  and general processing, including the execution of software stored on the computer-readable medium  706 . Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The software may reside on the computer-readable medium  706 , which may be a non-transitory computer-readable medium. A non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip), an optical disk (e.g., a compact disc (CD) or a digital versatile disc (DVD)), a smart card, a flash memory device (e.g., a card, a stick, or a key drive), a random access memory (RAM), a read only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), a register, a removable disk, and any other suitable medium for storing software and/or instructions that may be accessed and read by a computer. The computer-readable medium may also include, by way of example, a carrier wave, a transmission line, and any other suitable medium for transmitting software and/or instructions that may be accessed and read by a computer. 
     In one or more examples, the computer-readable storage medium  706  may include receiving software  752  including the instructions for receiving circuitry  740 . As illustrated, the computer-readable storage medium  706  may also include determination software  754  including the instructions for determination circuitry  742 . 
     It will be appreciated that the antenna adaptation discussed herein may also be practiced by a scheduling entity such as base station  700 . Such adaptation in base station  700  may be transparent to any specification or protocol such that the adaptation would also be transparent to any UEs. Alternatively, the base station adaptation may impact the specification such that at least the transmit antenna selection for base station  700  would be indicated to the UE or UEs served by base station  700 . 
     The disclosure will now be summarized in the following example clauses: 
     Clause 1. A method of wireless communication for a node, comprising: 
     receiving an antenna adaptation command at the node; 
     determining a combination of at least one transmit antenna and at least one receive antenna from a plurality of antenna combinations responsive to the antenna adaptation command, wherein the antenna adaptation command is valid for an antenna adaptation period; and communicating at the node using the determined combination of the at least one transmit antenna and the at least one receive antenna. 
     Clause 2. The method of clause 1, wherein the node is a user equipment (UE).
 
Clause 3. The method of clause 1, wherein the node is a base station.
 
Clause 4. The method of any of clauses 1-3, wherein the plurality of antenna combinations includes at least two of a 1T2R, 1T4R, 2T4R, 4T4R, 1T8R, 2T8R, 4T8R, and 8T8R transmit (T) and receive (R) antenna combinations.
 
Clause 5. The method of any of clauses 1-4, wherein the antenna adaptation period is a time slot.
 
Clause 6. The method of any of clauses 1-4, wherein the antenna adaptation period is a plurality of time slots.
 
Clause 7. The method of any of clauses 1-4, wherein the antenna adaptation period is a bandwidth part switching period.
 
Clause 8. The method of any of clauses 1-4, wherein the antenna adaptation period is a mini time slot.
 
Clause 9. The method of any of clauses 1-8, wherein the antenna adaptation command is based on a downlink control information (DCI) message.
 
Clause 10. The method of clause 9, wherein the DCI message is a plurality of DCI messages having at least a first DCI format in a first time instance and having a second DCI format in a second time instance, and wherein the antenna adaptation command is a first antenna adaptation command, the method further comprising:
 
     determining the first antenna adaptation command based on the first DCI format in the first time instance; and 
     determining a second antenna adaptation command based on the second DCI format in the second time instance. 
     Clause 11. The method of clause 10, wherein each DCI message in the plurality of DCI messages differs in a least one of a DCI decoding candidate and a DCI size.
 
Clause 12. The method of any of clauses 1-8, wherein the antenna adaptation command is based on a media access control (MAC) control element (CE) message.
 
Clause 13. The method of any of clauses 1-8, wherein the antenna adaptation command is based on a radio-resource-control-based message.
 
Clause 14. The method of any of clauses 1-13, wherein the antenna adaptation command is for a first component carrier, and wherein the communicating at the node is over a second component carrier.
 
Clause 15. The method of any of clauses 1-14, wherein a fallback antenna configuration for the node is dependent upon the determined combination of the at least one transmit antenna and the at least one receive antenna.
 
Clause 16. The method of any of clauses 1-14, wherein a fallback antenna configuration for the node is independent of the determined combination of the at least one transmit antenna and the at least one receive antenna.
 
Clause 17. The method of any of clauses 1-16, wherein the communicating at the node is a full-duplex communication, and wherein the at least one transmit antenna is not associated with any receive antenna.
 
Clause 18. The method of clause 2, further comprising:
 
     determining a channel state information (CSI) feedback based on the determined combination of the at least one transmit antenna and the at least one receive antenna; and 
     reporting the CSI feedback from the UE to a base station. 
     Clause 19. The method of clause 2, further comprising: 
     determining a sounding reference signal (SRS) configuration based on the determined combination of the at least one transmit antenna and the at least one receive antenna; and 
     transmitting an SRS based on the determined SRS configuration from the UE to a base station. 
     Clause 20. A method of wireless communication for a node, comprising: 
     during a first antenna adaptation period, transmitting from the node over a transmit set of transmit antennas according to a first data rate and receiving at the node over a receive set of antennas; 
     selecting a subset of the transmit antennas in the transmit set responsive to an antenna adaptation command; and 
     during a second antenna adaptation period, transmitting from the node over the subset of transmit antennas according to a second data rate that is lower than the first data rate. 
     Clause 21. The method of clause 20, wherein the antenna adaptation command is based upon at least one of a DCI message, a MAC CE message, and an RRC message.
 
Clause 22. The method of any of clauses 20-21, wherein the first antenna adaptation period is a first time slot and the second antenna adaptation period is a second time slot, and wherein the transmitting during the first time slot uses a transmit (T) and a receive (R) antenna configuration selected from a plurality of antenna configurations including a 1T2R configuration, a 1T4R configuration, a 2T4R configuration, a 4T4R configuration, a 1T8R configuration, a 2T8R configuration, a 4T8R configuration, and an 8T8R configuration.
 
Clause 23. The method of any of clause 20-22, wherein the antenna adaptation command is for at least one component carrier, and wherein the transmitting from the node during the second time slot is over the one component carrier.
 
Clause 24. A communication node, comprising:
 
     a set of antennas; 
     a processor configured to process a first antenna adaptation command that is valid for a first antenna adaptation period to determine a first subset of transmit antennas from the set of antennas and to determine a first subset of receive antennas from the set of antennas; and 
     a transceiver configured to communicate using the first subset of transmit antennas and the first subset of receive antennas during the first antenna adaptation period. 
     Clause 25. The communication node of clause 24, wherein the communication node is a user equipment (UE).
 
Clause 26. The communication node of clause 24, wherein the communication node is a base station.
 
Clause 27. The communication node of clause 26, wherein the processor is further configured to command the transceiver to transmit a message to a user equipment to identify to the user equipment that the base station is configured with the first subset of transmit antennas.
 
Clause 28. A wireless communication method for a base station, comprising:
 
     commanding a user equipment to use a first transmit and receive antenna selection during a first antenna adaptation period; and 
     commanding the user equipment to use a second transmit and receive antenna selection during a second antenna adaptation period to reduce an interference at the user equipment during the second antenna adaptation period. 
     Clause 29. The wireless communication method of clause 28, wherein the first transmit and receive antenna selection and the second transmit and receive antenna selection are both a transmit (T) and a receive (R) antenna configuration selected from a plurality of antenna configurations including a 1T2R configuration, a 1T4R configuration, a 2T4R configuration, a 4T4R configuration, a1T8R configuration, a2T8R configuration, a4T8R configuration, and an 8T8R configuration.
 
Clause 30. The wireless communication method of any of clauses 28-29, wherein the first antenna adaptation period is a first bandwidth part switching period and the second antenna adaptation period is a second bandwidth part switching period.
 
     Several aspects of a wireless communication network have been presented with reference to an exemplary implementation. As those skilled in the art will readily appreciate, various aspects described throughout this disclosure may be extended to other telecommunication systems, network architectures and communication standards. 
     By way of example, various aspects may be implemented within other systems defined by 3GPP, such as Long-Term Evolution (LTE), the Evolved Packet System (EPS), the Universal Mobile Telecommunication System (UMTS), and/or the Global System for Mobile (GSM). Various aspects may also be extended to systems defined by the 3rd Generation Partnership Project 2 (3GPP2), such as CDMA2000 and/or Evolution-Data Optimized (EV-DO). Other examples may be implemented within systems employing IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra-Wideband (UWB), Bluetooth, and/or other suitable systems. The actual telecommunication standard, network architecture, and/or communication standard employed will depend on the specific application and the overall design constraints imposed on the system. 
     Within the present disclosure, the word “exemplary” is used to mean “serving as an example, instance, or illustration.” Any implementation or aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects of the disclosure. Likewise, the term “aspects” does not require that all aspects of the disclosure include the discussed feature, advantage or mode of operation. The term “coupled” is used herein to refer to the direct or indirect coupling between two objects. For example, if object A physically touches object B, and object B touches object C, then objects A and C may still be considered coupled to one another—even if they do not directly physically touch each other. For instance, a first object may be coupled to a second object even though the first object is never directly physically in contact with the second object. The terms “circuit” and “circuitry” are used broadly, and intended to include both hardware implementations of electrical devices and conductors that, when connected and configured, enable the performance of the functions described in the present disclosure, without limitation as to the type of electronic circuits, as well as software implementations of information and instructions that, when executed by a processor, enable the performance of the functions described in the present disclosure. 
     One or more of the components, steps, features and/or functions illustrated in  FIGS.  1 - 7    may be rearranged and/or combined into a single component, step, feature or function or embodied in several components, steps, or functions. Additional elements, components, steps, and/or functions may also be added without departing from novel features disclosed herein. The apparatus, devices, and/or components illustrated in  FIGS.  1 - 7    may be configured to perform one or more of the methods, features, or steps escribed herein. The novel algorithms described herein may also be efficiently implemented in software and/or embedded in hardware. 
     It is to be understood that the specific order or hierarchy of steps in the methods disclosed is an illustration of exemplary processes. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the methods may be rearranged. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented unless specifically recited therein. 
     The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, b and c. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112(f) unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”