Antenna element set selection system

Abstract

The present disclosure generally relates to systems, devices, apparatuses, products, and methods for wireless communication. For example, a user equipment (UE) within a wireless communication system determines one or more performance metrics associated with the operation of the UE. At least partially based on the one or more performance metrics, the UE selects one or more antenna element sets from a plurality of antenna element sets available for inter-band carrier aggregation communication between the UE and one or more base stations across at least two radio frequency (RF) chains. The UE transmits an indication of the one or more selected antenna element sets from the UE to the one or more base stations.

Description

[0001] Priority Claim

[0002] This application claims the benefit and priority of U.S. Patent Application No. 16 / 554,049, filed on August 28, 2019, with the United States Patent and Trademark Office, the entire content of which is incorporated herein by reference in its entirety as set forth below and for all applicable purposes. Field of Technology

[0003] The present disclosure generally relates to wireless communication, and more particularly to antenna unit set selection techniques. Background Art

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcasting, and other types of content. These systems are capable of supporting communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multi-access systems include fourth-generation (4G) systems such as Long Term Evolution (LTE) systems, Advanced LTE (LTE-A) systems, or LTE-A Pro systems, and fifth-generation (5G) systems that may be referred to as New Radio (NR) systems. These systems may employ techniques such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), or Discrete Fourier Transform Spread Orthogonal Frequency Division Multiplexing (DFT-S-OFDM). A wireless multi-access communication system may include a plurality of base stations or network access nodes that may simultaneously support communication for a plurality of communication devices (e.g., user equipment (UE)).

[0005] Some wireless networks may utilize higher frequencies and shorter wavelengths to provide higher data rates. As an example, millimeter wave (mmW) devices with fifth-generation (5G) capabilities may communicate using frequencies in or near the Extremely High Frequency (EHF) spectrum and wavelengths in or near the millimeter wavelength. While higher frequency signals provide greater bandwidth to efficiently transmit large amounts of data, these signals are subject to higher path loss (e.g., path attenuation). To compensate for the higher path loss, the transmit power level may be increased, or beamforming may be used to concentrate the energy in a specific direction.

[0006] In some cases, a wireless device (e.g., a UE) can be configured with multiple antenna units, which are organized into multiple antenna panels or arrays. The UE can use the multiple antenna units for beamforming communication with another device (e.g., using mmW communication technology). For example, the UE can use one or more of its antenna units to receive a beamformed signal transmitted from a base station to the UE. Additionally, the UE can use one or more of its antenna units to transmit a beamformed signal from the UE to the base station. When multiple different antenna units or different combinations of antenna units are available for a given communication scenario, a question arises as to which antenna unit or which combination of antenna units the UE should select for communication. SUMMARY

[0007] Each of the systems, methods, and devices of the present disclosure has several innovative aspects, none of which alone is the feature solely responsible for the desired attributes disclosed herein. The present disclosure generally relates to systems, devices, apparatuses, products, and methods for wireless communication.

[0008] As an example, the present disclosure relates to systems, devices, apparatuses, products, and methods for a user equipment (UE) regarding determining one or more performance metrics associated with the operation of the UE. At least partially based on the one or more performance metrics, the UE selects one or more antenna unit sets (the antenna unit sets can also be referred to as sub-arrays) from a plurality of antenna unit pools available for inter-band carrier aggregation communication between the UE and one or more base stations across at least two radio frequency (RF) chains. The UE transmits an indication of the one or more selected antenna unit sets from the UE to the one or more base stations.

[0009] As another example, the present disclosure relates to systems, devices, apparatuses, products, and methods for a base station regarding receiving an indication of one or more antenna unit sets of the UE selected by the UE for inter-band carrier aggregation communication between the UE and one or more base stations. The base station selects at least a first base station beam based on the indication of the one or more antenna unit sets selected by the UE. The base station uses at least the first base station beam to perform at least a part of the inter-band carrier aggregation communication between the UE and the base station. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present system can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the present disclosure. Further, in the figures, like reference numerals designate corresponding parts throughout the different views.

[0011] Figure 1 An example of a wireless communication system supporting antenna unit set selection techniques in accordance with aspects of the present disclosure is shown.

[0012] Figure 2Shows an example of a part of a wireless communication system that uses beamforming transmission and supports antenna element set selection technology.

[0013] Figure 3 Is an illustration of a wireless communication device (e.g., UE) configured to support antenna element set selection technology.

[0014] Figure 4 Is an illustration of a wireless communication device (e.g., base station) configured to support antenna element set selection technology.

[0015] Figure 5 Is an illustration of a wireless communication device having multiple antenna elements dispersed over multiple antenna modules.

[0016] Figure 6 Is a first example of an antenna element set selection process based on one or more performance metrics.

[0017] Figure 7 Is a second example of an antenna element set selection process based on one or more performance metrics.

[0018] Figure 8 Is a flowchart showing an example of a technique for a UE to send an indication of antenna element set selection for inter-band carrier aggregation communication.

[0019] Figure 9 Is a flowchart showing an example of a technique for a base station to receive an indication of antenna element set selection for inter-band carrier aggregation communication.

[0020] Figure 10 Is a message flowchart showing an antenna element set selection process for inter-band carrier aggregation communication.

[0021] Figure 11 Is a first example of a beam training process between a UE and a base station.

[0022] Figure 12 Is a second example of a beam training process between a UE and a base station. Detailed Description

[0023] The detailed description set forth below in connection with the accompanying drawings is intended as a description of various configurations and is not intended to represent that the concepts described herein can only be implemented in these configurations. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be implemented without these specific details.

[0024] The systems and techniques described in this detailed description provide various mechanisms for selecting one or more sets of antenna elements for inter-band carrier aggregation communication between a first wireless communication device (e.g., a UE) and one or more second wireless communication devices (e.g., one or more base stations). Carrier aggregation communication split across multiple base stations can also be implemented as dual connectivity communication.

[0025] On the UE side, carrier aggregation implementations can utilize different numbers of RF chains across a single carrier or multiple carriers. Some UE carrier aggregation implementations can be limited to at most two radio frequency (RF) chains (e.g., 2Rx / 2Tx), each time on only a single carrier (e.g., only within the 28 GHz band, only within the 39 GHz band, or only within any single defined band for 5G New Radio). Other UE carrier aggregation implementations can support more than two RF chains. For example, some UE implementations can use up to four, eight, or more RF chains (e.g., 4Rx / 2Tx, 4Rx / 4Tx, 8Rx / 2Tx, 8Rx / 4Tx, 8Rx / 8Tx, 16Rx / 4Tx, 16Rx / 8Tx, 16Rx / 16Tx, etc.). These RF chains can be used for communication using different beams, carriers, and / or antenna modules.

[0026] As RF chain capabilities evolve, communication systems can support both intra-band carrier aggregation and inter-band carrier aggregation. Intra-band carrier aggregation uses two or more component carriers from within one defined band. For example, when considering millimeter-wave communication, intra-band carrier aggregation communication can use two or more component carriers from within only one of the 24 GHz band, 26 GHz band, 28 GHz band, 39 GHz band, 42 GHz band, 60 GHz band, 73 GHz band, or any other defined band. Inter-band carrier aggregation uses two or more component carriers, where at least one component carrier is from within one defined band and at least one component carrier is from a different defined band. For example, when considering millimeter-wave communication, inter-band carrier aggregation communication can use one or more component carriers from within a first of the 24 GHz, 26 GHz, 28 GHz, 39 GHz, 42 GHz, 60 GHz, or 73 GHz bands (or any other defined band), and one or more component carriers from within a different one of the 24 GHz, 26 GHz, 28 GHz, 39 GHz, 42 GHz, 60 GHz, or 73 GHz bands (or any other defined band). Inter-band carrier aggregation can also aggregate one or more component carriers from within the millimeter-wave band with one or more component carriers from outside the millimeter-wave band (e.g., sub-6 GHz component carriers, other frequency range 1 (FR1) component carriers, or any non-millimeter-wave component carriers).

[0027] As an example, the 3GPP RAN4 agreement detailed in R4-1902678 indicates different operating frequency bands and band classes, where bands n257, n258, and n261 can be considered as 24 / 28 GHz bands, while band n260 can be considered as a 39 GHz band. In-band carrier aggregation can be supported within a certain band class (aggregation of carriers within a single band class, such as one of n257, n258, n260, or n261). Inter-band carrier aggregation can be supported across multiple band classes (aggregation of carriers in different band classes).

[0028] The UE may include many different antenna elements organized into one or more antenna modules. Each module may include multiple sub-arrays of antenna elements. Some antenna modules may include different types of antenna elements, such as broadband antennas (e.g., dipoles) or narrowband antennas (e.g., patches). Other antenna types, such as slot antennas, waveguide antennas, monopole antennas, etc., may also be included. Additionally, some antenna elements may be configured or optimized for communication within a certain frequency band or polarization. For example, an antenna module may include a patch antenna customized to operate at a specific frequency band (e.g., 28 GHz or 39 GHz or any other frequency band) and at a specific polarization (e.g., horizontal polarization (HPol) or vertical polarization (VPol)). The module may have dedicated antenna elements for each of these combinations of frequency band and polarization (e.g., a patch antenna for 28 GHz horizontal polarization, a patch antenna for 28 GHz vertical polarization, a patch antenna for 39 GHz horizontal polarization, a patch antenna for 39 GHz vertical polarization, a dipole antenna for covering a certain polarization at 28 and 39 GHz, etc.). If the UE supports other frequency bands, then the UE may also require additional antenna elements customized for those frequency bands. Thus, as the number of frequency bands supported by the UE increases, the number of antenna elements in the UE also increases.

[0029] As the number of frequency bands supported by the UE increases and / or the number of RF chains allowed at the UE increases, the number of different combinations of antenna elements that can be used at the UE to support all possible combinations of frequency bands and RF chains also increases significantly, especially when considering inter-band carrier aggregation communication. The complexity of managing a large number of possible combinations of frequency bands and RF chains is very high. As an example, at a certain point in time, the number of supported frequency bands and allowed RF chains may become so high that during some operating conditions (e.g., mobility, channel coherence, latency for WW applications, etc.), the UE cannot use an exhaustive search method to check all possible combinations of antenna elements within the amount of time available for making an antenna element selection. Thus, the techniques disclosed herein propose various methods for improved antenna element set or sub-array selection in a carrier aggregation system.

[0030] Figure 1FIG. 0 illustrates an example of a wireless communication system 100 that supports techniques for selecting one or more sets of antenna units for inter-band carrier aggregation communication between a first wireless communication device (e.g., a UE) and one or more second wireless communication devices (e.g., one or more base stations) based on performance metrics. The wireless communication system 100 includes a base station 105, a UE 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long-Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, a Fifth Generation (5G) New Radio (NR) network, or another type of network. In some cases, the wireless communication system 100 may support enhanced broadband communication, ultra-reliable (e.g., mission-critical) communication, low-latency communication, or communication with low-cost and low-complexity devices.

[0031] The base station 105 may communicate wirelessly with the UE 115 via one or more base station antennas. The base station 105 described herein may include or may be referred to by those skilled in the art as a base station transceiver, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or giga-NodeB (either of which may be referred to as a gNB), a home NodeB, a home eNodeB, or some other suitable term. The wireless communication system 100 may include different types of base stations 105 (e.g., macro or small cell base stations). The UE 115 described herein is capable of communicating with various types of base stations 105 and network devices, including macro eNBs, small cell eNBs, gNBs, relay base stations, and the like.

[0032] Each base station 105 may be associated with a particular geographic coverage area 110 in which communication with respective UEs 115 is supported. Each base station 105 may provide communication coverage for its respective geographic coverage area 110 via a communication link 125, and the communication link 125 between the base station 105 and the UE 115 may utilize one or more carriers. The communication link 125 shown in the wireless communication system 100 may include an uplink transmission from the UE 115 to the base station 105 or a downlink transmission from the base station 105 to the UE 115. A downlink transmission may also be referred to as a forward link transmission, and an uplink transmission may also be referred to as a reverse link transmission.

[0033] The geographical coverage area 110 of the base station 105 can be divided into sectors that form part of the geographical coverage area 110, and each sector can be associated with a cell. For example, each base station 105 can provide communication coverage for macro cells, small cells, hotspots, or other types of cells, or various combinations thereof. In some examples, the base station 105 is movable, and thus can provide communication coverage for a movable geographical coverage area 110. In some examples, different geographical coverage areas 110 associated with different technologies can overlap, and the overlapping geographical coverage areas 110 associated with different technologies can be supported by the same base station 105 or different base stations 105. The wireless communication system 100 can include, for example, a heterogeneous LTE / LTE-A / LTE-A Pro or NR network, where different types of base stations 105 provide coverage for each geographical coverage area 110.

[0034] UEs 115 can be scattered throughout the wireless communication system 100, and each UE 115 can be fixed or mobile. A UE 115 can also be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable term, where the device can also be referred to as a unit, a station, a terminal, or a client. A UE 115 can also be a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, a UE 115 can also refer to a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communication (MTC) device, etc., which can be implemented in various items, such as appliances, vehicles, meters, etc.

[0035] In some cases, a UE 115 is also capable of directly communicating with other UEs 115 (e.g., using a peer-to-peer (P2P) or device-to-device (D2D) protocol). One or more groups of UEs 115 that employ D2D communication can be within the geographical coverage area 110 of the base station 105. Other UEs 115 in the group can be outside the geographical coverage area 110 of the base station 105 or cannot receive transmissions from the base station 105 for other reasons. In some cases, a group of UEs 115 that communicate via D2D can employ a one-to-many (1:M) system, where each UE 115 sends to each other UE 115 in the group. In some cases, the base station 105 implements scheduling of resources for D2D communication. In other cases, D2D communication can be performed between UEs 115 without involving the base station 105.

[0036] Base station 105 can communicate with core network 130 and can communicate with each other. For example, base station 105 can be connected to core network 130 via a backhaul link 132 (e.g., via S1, N2, N3, or other interfaces). Base station 105 can communicate with each other via a backhaul link 134 (e.g., via X2, Xn, or other interfaces) or directly (e.g., directly between base stations 105) or indirectly (e.g., via core network 130).

[0037] Core network 130 can provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. Core network 130 can be an evolved packet core (EPC), which can include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one packet data network (PDN) gateway (P-GW). The MME can manage non-access stratum (e.g., control plane) functions, such as mobility, authentication, and bearer management for UE 115, which is served by base station 105 associated with the EPC. User IP packets can be transmitted through the S-GW, which can itself be connected to the P-GW. The P-GW can provide IP address allocation and other functions. The P-GW can be connected to the network operator IP services. The operator IP services can include access to the Internet, intranet, IP multimedia subsystem (IMS), or packet switched (PS) streaming services.

[0038] At least some of the network devices, such as base station 105, can include sub-components, such as access network entities, which can be an example of an access node controller (ANC). Each access network entity can communicate with UE 115 via multiple other access network transmission entities called radio heads, intelligent radio heads, or transmit / receive points (TRP). In some configurations, the functions of each access network entity or base station 105 can be distributed across various network devices (e.g., radio heads and access network controllers), or consolidated into a single network device (e.g., base station 105).

[0039] Wireless communication system 100 can operate using one or more frequency bands typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally, since the wavelength range is from approximately one decimeter to one meter in length, the region from 300 MHz to 3 GHz is called the ultra-high frequency (UHF) region or the decimeter band. UHF waves can be blocked or redirected by buildings and environmental features. However, for macro cells, these waves are sufficient to penetrate structures to provide service to UE 115 located indoors. Compared to transmissions using smaller frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz, UHF wave transmissions can be associated with smaller antennas and shorter distances (e.g., less than 100 km).

[0040] The wireless communication system 100 may also operate in the super high frequency (SHF) region, also known as the centimeter band, using a frequency band from 3 GHz to 30 GHz. The SHF region includes bands such as the 5 GHz industrial, scientific, and medical (ISM) band, which can be opportunistically used by devices that can tolerate interference from other users.

[0041] The wireless communication system 100 may also operate in the extremely high frequency (EHF) spectrum region (e.g., from 30 GHz to 300 GHz), also known as the millimeter band. In some systems, millimeter wave (mmW) communication may occur in frequency bands (also referred to as frequency range 2 "FR2") located at 24 GHz or above, which may include portions of the millimeter band and near-millimeter band within the overall frequency band. In some examples, the wireless communication system 100 may support millimeter wave (mmW) communication between the UE 115 and the base station 105, and the EHF antennas of the corresponding devices may even be smaller and closer-spaced than UHF antennas. In some cases, this facilitates the use of antenna arrays within the UE 115. However, the propagation of EHF transmissions suffers even greater atmospheric attenuation and shorter distances than SHF or UHF transmissions. The techniques disclosed herein may be used across transmissions using one or more different frequency regions, and the specified use of frequency bands across these frequency regions may vary by country or regulatory body.

[0042] In some cases, the wireless communication system 100 may employ licensed and unlicensed radio spectrum bands. For example, the wireless communication system 100 may use licensed-assisted access (LAA), LTE-unlicensed (LTE-U) radio access technology, or NR technology in unlicensed bands such as the 5 GHz ISM band. When operating in the unlicensed radio spectrum band, wireless devices such as the base station 105 and the UE 115 may use a listen-before-talk (LBT) procedure to ensure that the frequency channel is idle before transmitting data. In some cases, operation in the unlicensed band may be based on a carrier aggregation configuration that combines a component carrier operating in a licensed band (e.g., LAA). Operation in the unlicensed spectrum may include downlink transmissions, uplink transmissions, end-to-end transmissions, or a combination thereof. Duplexing in the unlicensed spectrum may be based on frequency-division duplexing (FDD), time-division duplexing (TDD), or a combination of both.

[0043] In some examples, the base station 105 or the UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. For example, the wireless communication system 100 may use a transmission scheme between a transmitting device (e.g., the base station 105) and a receiving device (e.g., the UE 115), where the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas. MIMO communication can use multipath signal propagation to increase spectral efficiency by transmitting or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing. The multiple signals may be transmitted, for example, by the transmitting device via different antennas or different combinations of antennas. Similarly, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as an independent spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO) where multiple spatial layers are transmitted to the same receiving device, and multi-user MIMO (MU-MIMO) where multiple spatial layers are transmitted to multiple devices.

[0044] Beamforming, also known as spatial filtering, directional transmission, or directional reception, is a signal processing technique that can be used at a transmitting device or a receiving device (e.g., the base station 105 or the UE 115) to shape or manipulate an antenna beam (e.g., a transmit beam or a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming can be achieved by combining signals transmitted via the antenna elements of an antenna array such that the signal propagation in a particular direction for the antenna array experiences constructive interference while others experience destructive interference. The adjustment of the signals transmitted via the antenna elements may include the transmitting device or the receiving device applying a certain amplitude and phase offset to the signals carried by each antenna element associated with the device. The adjustment associated with each antenna element may be defined by a set of beamforming weights associated with a particular direction (e.g., with respect to the antenna array of the transmitting device or the receiving device, or with respect to some other direction).

[0045] In one example, the base station 105 may use multiple antenna elements or an antenna array to perform beamforming operations for directional communication with the UE 115. For example, some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by the base station 105 multiple times in different directions, which may include signals transmitted according to different sets of beamforming weights associated with different transmission directions. The transmissions in different beam directions may be used (e.g., by the base station 105 or a receiving device such as the UE 115) to identify the beam direction for subsequent transmissions and / or receptions by the base station 105.

[0046] Some signals, such as data signals associated with a particular receiving device, may be transmitted by base station 105 in a single beam direction (e.g., the direction associated with a receiving device such as UE 115). In some examples, the beam direction associated with transmission in a single beam direction may be determined at least in part based on signals transmitted in different beam directions. For example, UE 115 may receive one or more of the signals transmitted by base station 105 in different directions, and UE 115 may report to base station 105 an indication of the signal that it received with the highest signal quality or otherwise acceptable signal quality. Although these techniques are described with reference to signals transmitted by base station 105 in one or more directions, UE 115 may use similar techniques for transmitting signals multiple times in different directions (e.g., for identifying beam directions for subsequent transmissions or receptions by UE 115), or for transmitting signals in a single direction (e.g., for transmitting data to a receiving device).

[0047] When receiving various signals such as synchronization signals, reference signals, beam selection signals, or other control signals from base station 105, a receiving device (e.g., UE 115, which may be an example of a millimeter wave receiving device) may attempt multiple receive beams. For example, the receiving device may attempt multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different sets of receive beamforming weights applied to signals received by multiple antenna elements in an antenna array, or by processing received signals according to different sets of receive beamforming weights applied to signals received by multiple antenna elements in an antenna array, any of which may be referred to as "listening" according to different receive beams or receive directions. In some instances, the receiving device may use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal). The single receive beam may be aligned with a beam direction determined at least in part based on listening according to different receive beam directions (e.g., a beam direction having the highest signal strength, highest signal-to-noise ratio, or otherwise acceptable signal quality determined at least in part based on listening according to multiple beam directions).

[0048] In some cases, the antenna units of base station 105 or UE 115 can be located within one or more antenna arrays that support MIMO operations, or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays can be co-located at an antenna assembly, such as an antenna tower. In some cases, the antennas or antenna arrays associated with base station 105 can be located in geographically dispersed locations. Base station 105 can have an antenna array that has multiple rows and columns of antenna ports that base station 105 can use to support beamforming for communication with UE115. Similarly, UE 115 can have one or more antenna arrays that support various MIMO or beamforming operations.

[0049] In wireless communication system 100, one or more of UEs 115 can be configured to dynamically select one or more sets of antenna units that may be used for planned inter-band carrier aggregation communication (e.g., multi-band communication with one or more base stations 105). The selection by the UE can be based on one or more performance metrics regarding the operation of the UE. After selecting one or more preferred sets of antenna units, the UE notifies the base station of the selection. Further details of the antenna unit set selection algorithm are described in more detail below.

[0050] Figure 2 An example of a portion of wireless communication system 200 that uses beamforming transmission and supports antenna unit set selection based on performance metrics for inter-band carrier aggregation communication is shown. In some examples, wireless communication system 200 can implement aspects of wireless communication system 100. In Figure 2 the example, wireless communication system 200 can include base station 105-a and UE 115-a, which can be examples of the corresponding devices referenced Figure 1 described. In this example, UE 115-a and base station 105-a can use beamformed communication to establish a connection via one or more beams 205 at the base station and one or more beams 210 at the UE.

[0051] In some cases, base station 105-a and UE 115-a may establish communication via a beam pair link using base station beam 205 and UE beam 210, which are determined based on a beam training process (e.g., P1 initial beam training process, P2 / P3 beam optimization process, etc.). During the beam training process, UE 115-a and base station 105-a may measure one or more parameters of the beams transmitted in a beam sweep sequence. Such measurements can be used to determine a specific beam pair to be used for communication. In some cases, one or more reference signals may be measured to determine one or more beams to be used for communication. For example, base station 105-a may transmit reference signals (e.g., one or more synchronization signals in one or more synchronization signal blocks (SSBs), channel state information reference signals (CSI-RS), or a combination thereof) on a series of beams 205, and the reference signals may be measured at UE 115-a to provide measurement reports used to select (e.g., based on a beam reciprocity assumption) a preferred base station beam 205, a preferred UE beam 210, or both.

[0052] In some cases, UE 115-A and base station 105-A may communicate regarding one or more preferred sets of antenna elements. For example, UE 115-A may send an indication of one or more preferred sets of UE antenna elements to be used during inter-band carrier aggregation communication to the base station. The base station 105-A may then use this indication to focus its beam selection or beam training procedures on the beams most likely associated with the selected set of UE antenna elements. Further details regarding the use of preferred antenna element set indications in beam training and selection procedures will be described in more detail below.

[0053] Figure 3 is a diagram of system 300 that includes device 305 configured to select one or more sets of antenna elements based on performance metrics for inter-band carrier aggregation communication. Device 305 may be an example of UE 115 as described in connection with Figure 1 and 2 Device 305 may include components for two-way voice and data communication, which include components for transmitting and receiving communication, including one or more communication managers 310, one or more RF chain components 315, one or more transceivers 320, one or more antenna elements 325, one or more memory devices 330, one or more processors 340, and one or more I / O controllers 350. These components may communicate electronically via one or more buses (e.g., bus 355).

[0054] The communication manager 310 may manage the processes of generating, transmitting, receiving, and processing received signals. The communication manager 310 may work together with other components of the device 305 (e.g., the processor 340, the transceiver 320, the antenna unit 325, and other RF chain components) to perform the various communication functions described herein. When operating as part of an antenna unit set selection system at the device 305, the communication manager 310 may manage the process of selecting one or more desired antenna unit sets based on performance metrics (e.g., as described below in connection with Figures 6 - 12 ). The communication manager 310 may include its own processor or may be a functional component of the processor 340.

[0055] The transceiver 320 may communicate bidirectionally via one or more antenna units (e.g., the antenna unit 325). For example, the transceiver 320 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 320 may also include a modem to modulate packets and provide the modulated packets to the antenna unit for transmission, and to demodulate packets received from the antenna unit. The transceiver 320 may send the received signals to another component (e.g., the processor 340 or the communication manager 310) for further processing.

[0056] The device 305 may have multiple antenna units 325 that are capable of simultaneously transmitting or receiving multiple wireless transmissions. The antenna units 325 may be organized within one or more antenna arrays or panels. The antenna units 325 may receive radio waves corresponding to the content of the downlink signals and transmit the received signals to the transceiver 320 for further processing. The antenna units 325 may also receive the content of the uplink signals from the transceiver 320 and radiate radio waves corresponding to the content of the uplink signals.

[0057] The device 305 may include RF chain components 315 that may process the signals between the antenna unit 325 and the transceiver 320. For example, the RF chain components 315 may include one or more of the following: a radio frequency integrated circuit (RFIC), an amplifier, a filter, a converter, an oscillator, a phase shifter, a mixer, an attenuator, or a detector. The RF chain components 315 may process outgoing signals sent from the modem / transceiver destined for the antenna unit. The RF chain components 315 may also process incoming signals received from the antenna unit destined for the modem / transceiver.

[0058] The memory 330 of device 305 may include RAM, ROM, or a combination thereof. The memory 330 may store computer-readable code 335 that includes instructions which, when executed by a processor (e.g., the processor 340 in device 305 or another processor, such as a processor associated with transceiver 320, modem, or communication manager 310), cause device 305 to perform the various communication functions described herein. In some cases, among other things, the memory 330 may include BIOS, which may control basic hardware or software operations, such as interactions with peripheral components or devices. The memory 330 may also include instructions that cause device 305 to perform the antenna array set selection features described herein.

[0059] The code 335 may include instructions implementing aspects of the present disclosure, which include instructions for selecting an antenna unit set and otherwise supporting wireless communication. The code 335 may be stored in a non-transitory computer-readable medium, such as system memory or other types of memory. In some cases, the code 335 cannot be directly executed by the processor 340, but rather causes the device (e.g., when compiled and executed) to perform the functions described herein.

[0060] The processor 340 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, the processor 340 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into the processor 340. The processor 340 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 330) to cause device 305 to perform various functions (e.g., in conjunction with Figures 6 - 12 the functions described).

[0061] The I / O controller 350 may manage input and output signals for device 305. The I / O controller 350 may also manage peripheral devices not integrated in device 305. In some cases, the I / O controller 350 may represent a physical connection or port to external peripheral devices. In some cases, the I / O controller 350 may use an operating system, such as or another known operating system. In other cases, the I / O controller 350 may represent a modem, keyboard, mouse, touch screen, or similar device, or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, the I / O controller 350 may be implemented as part of a processor. In some cases, a user may interact with device 305 via the I / O controller 350 or hardware components controlled by the I / O controller 350.

[0062] Figure 3 The components of the apparatus 305 shown in may be combined into a fewer number of components, or the functionality described herein may be divided into a greater number of components. As an example of the ability to combine functionality, the functionality of the I / O controller 350 and / or the functionality of the communication manager 310 may be combined with other control and processing functionality and performed by the processor 340 (based on instructions stored in the memory 330). Thus, Figure 3 the configuration shown in represents an example configuration, and additional structural configurations are intended to be within the scope of the present disclosure.

[0063] Figure 4 is a diagram of a system 400 that includes an apparatus 405 configured to receive an indication of a UE's selection of one or more antenna element sets based on performance metrics for inter-band carrier aggregation communication. The apparatus 405 may be an example of a base station 105 as described in connection with Figure 1 and 2 . The apparatus 405 may include components for two-way voice and data communication, which include components for transmitting and receiving communication, including one or more communication managers 410, one or more RF chain components 415, one or more transceivers 420, one or more antenna elements 425, one or more memory devices 430 (including code 435), one or more processors 440, and one or more I / O controllers 450. These components may communicate electronically via one or more buses (e.g., bus 455). The components 410, 415, 420, 425, 430, 435, 440, 450, and 455 of the apparatus 405 may perform functions similar to the corresponding components 310, 315, 320, 325, 330, 335, 340, 350, and 355 described above in connection with the apparatus 305 ( Figure 3 ). However, the components of the apparatus 405 will perform actions from the perspective of a base station rather than from the perspective of a UE. For example, when operating as part of an antenna element set selection system on the apparatus 405, the components of the apparatus 405 may operate to communicate with the UE, cooperate with the UE to select one or more desired antenna element sets, and participate in inter-band carrier aggregation communication (e.g., as described below in connection with Figures 6 - 12 ).

[0064] Figure 5 is a diagram of a UE 500 that supports antenna element set selection for inter-band carrier aggregation according to one embodiment. The UE 500 may be an example of a UE shown in the previous figures, such as Figure 1 and 2 's UE 115 or Figure 3 's apparatus 305. In Figure 5The UE 500 shown in the example includes a plurality of antenna modules, and the plurality of antenna modules include a first antenna module 502, a second antenna module 504, and a third antenna module 506. Other implementations may include fewer antenna modules (e.g., one antenna module or two antenna modules) or more antenna modules (e.g., four or more antenna modules) than the example shown. The antenna modules 502, 504, and 506 are shown on different sides of the UE 500 towards different planar directions to provide modular spatial coverage for the UE 500 in different directions. Figure 5 The example shown may include fewer antenna modules (e.g., one antenna module or two antenna modules) or more antenna modules (e.g., four or more antenna modules) than those shown. The antenna modules 502, 504, and 506 are shown on different sides of the UE 500 towards different planar directions to provide modular spatial coverage for the UE 500 in different directions.

[0065] Each of the antenna modules 502, 504, and 506 may include one or more arrays or sub-arrays of antenna elements 508. In some implementations, each of the antenna modules 502, 504, and 506 is equipped with antennas sharing one or more RF chains across different frequency bands. Example frequency bands include one or more of the 24 GHz band, 26 GHz band, 28 GHz band, 39 GHz band, 42 GHz band, 60 GHz band, 73 GHz band, or 85+ GHz band. Other millimeter wave bands, sub-6 GHz bands, or other frequency bands may also be supported by the antenna elements 508.

[0066] In some implementations, the antenna elements 508 may include patch antenna elements, dipole antenna elements, or both. The dipole antenna elements may be broadband and span one or more frequency bands. The patch antenna elements (or other types of narrowband antennas) may each be designed to operate in a specific frequency band. The UE may have one or more patch antennas designed for each individual frequency band supported by the device. For example, a UE that supports operation in both the 28 GHz and 39 GHz frequency bands may include one or more patch antenna elements optimized for the 28 GHz band and one or more patch antenna elements optimized for the 39 GHz band. As another example, a UE that supports operation in three different frequency bands may include one or more patch antenna elements optimized for the first band, one or more patch antenna elements optimized for the second band, and one or more patch antenna elements optimized for the third band. Additional bands (e.g., more than three bands) and corresponding dedicated antenna elements may also be supported in the UE.

[0067] The antenna elements 508 can be grouped into sub-arrays corresponding to horizontal polarization (HPol) or vertical polarization (VPol). As an example, an antenna sub-array (e.g., the antenna elements in a module) supporting 28 GHz and 39 GHz can include the following antenna elements: 1) Patch 28HPol; 2) Patch 28VPol; 3) Patch 39HPol; 4) Patch 39VPol; and 5) Dipole (broadband). In other implementations, different configurations of antenna elements can be included in the sub-array or module. For example, the device can support additional frequency bands and thus include additional patch antenna elements customized for the additional frequency bands.

[0068] According to one embodiment, each antenna module 502, 504, and 506 can be controlled by a radio frequency integrated circuit (RFIC), and the RF chain of the UE can be switched between different antenna modules 502, 504, and 506 to provide transmission and reception of wireless signals based on the beam direction desired by the base station or cell. Based on the number of RF chains available on the UE 500 and the number of RF chains that each antenna module can operate, the UE 500 can have different options for selecting a set of antenna elements to support inter-band carrier aggregation.

[0069] In some implementations, when the UE includes multiple antenna modules and supports multiple RF chains, the UE can include restrictions on the simultaneous use of modules and RF chains. As a first example, the UE can be restricted to using a maximum of two RF chains per module simultaneously and a maximum of two RF chains simultaneously across the entire UE. As a second example, the UE can be restricted to using a maximum of two RF chains per module simultaneously and a maximum of four RF chains simultaneously across the entire UE. As a third example, the UE can be restricted to using a maximum of four RF chains per module simultaneously and a maximum of four RF chains simultaneously across the entire UE. As a general example, the UE can be restricted to using a maximum of "K" RF chains per module simultaneously and a maximum of "L" RF chains simultaneously across the entire UE (e.g., across all antenna modules of the UE), where K is less than or equal to L.

[0070] As the number of frequency bands supported by the UE increases, the number of antenna elements in the UE also increases. As the number of frequency bands supported by the UE increases and / or the number of RF chains allowed at the UE increases, the number of different combinations of antenna elements that can be used at the UE to support all possible frequency band and RF chain combinations also increases significantly, especially when considering inter-band carrier aggregation communications. Thus, the techniques disclosed herein present various methods for improved antenna element set selection in a carrier aggregation system.

[0071] Figure 6is a first example of a process for selecting one or more sets of antenna elements (e.g., selecting between antenna element sets 616, 618, 620, 622, or 624) based on one or more performance metrics (e.g., performance metrics 602, 604, 606, 608, 610, 612, or 614). In other implementations, the system may consider any number of performance metrics (e.g., more or fewer performance metrics than Figure 6 shown), and may select between any number of sets of antenna elements (e.g., more or fewer sets of antenna elements than Figure 6 shown, such as including different combinations of elements or adding antenna elements for additional frequency bands). In Figure 6 the example, certain performance metrics are associated with certain sets of antenna elements that can be used together for carrier aggregation communications such as inter-band carrier aggregation.

[0072] Performance metrics 602, 604, 606, 608, 610, 612, and 614 can represent any performance or operational goal / target of the UE. Performance metric 602 can represent a data rate metric. The data rate metric can be determined by comparing the measured data rate with a target rate threshold. For example, the data rate threshold can check whether the received or transmitted data rate is high enough for the UE's performance goal. Performance metric 604 can represent a power metric. The power metric can be determined by comparing the measured power metric with a power threshold. As an example, the power metric can be compared with a battery level threshold to check the remaining battery capacity. As another example, the power metric can be compared with a power usage threshold to check the power usage estimate. Performance metric 606 can represent a spectral efficiency metric. The spectral efficiency metric can be determined by comparing the measured spectral efficiency with a spectral efficiency threshold. Performance metric 608 can represent a beam management metric. The beam management metric can consider the overhead associated with the beam management process. Performance metric 610 can represent a robustness metric for polarization loss. The robustness metric for polarization loss can consider how robust the transmission / reception is to the loss of polarization (e.g., in some scenarios, the ability to distinguish HPol from VPol is lost). For example, as the radio signal undergoes multiple reflections on multiple reflectors, buildings, or scatterers, only pure HPol or pure VPol transmissions can be received at the receiver on a particular polarization independent of the transmission. In other words, due to multiple reflections in the channel environment, the transmitted polarization is lost. Performance metric 612 can represent a robustness metric for blockage. The robustness metric for blockage can consider how likely the planned transmission / reception will be blocked by external obstacles. Such a determination will depend on the channel environment where the transmission / reception occurs (e.g., indoor hotspot, mall, outdoor, suburban environment, business district, stadium, etc.). Performance metric 614 can represent a heat metric. The heat metric can be determined by comparing the measured heat metric with a target heat threshold. For example, the heat metric can check whether the temperature of the UE is above or below the threshold.

[0073] Figure 6 The antenna element set selection process of realizes that when considering a specific performance goal, some antenna element sets may be more advantageous than others. For example, some combinations of antenna elements may use more power than other combinations of antenna elements. As another example, some combinations of antenna elements may allow for a higher data rate than other combinations of antenna elements. As yet another example, some combinations of antenna elements may be more robust to potential beam blockage than other combinations of antenna elements. As another example, some combinations of antenna elements may result in a higher device temperature than other combinations of antenna elements. Further examples for each example RF chain configuration are provided below.

[0074] In an implementation where the UE is restricted to two RF chains per antenna module and a total of two RF chains across all modules of the UE, the UE can select a first type of antenna element set, a second type of antenna element set, a third type of antenna element set, or a fourth type of antenna element set. Each type of antenna element set can have unique properties that bring various benefits or trade - offs.

[0075] The first type of antenna element set can include patches of two orthogonal polarizations (HPol and VPol) within the same band / carrier (e.g., patch 28HPol, patch 28VPol). This type of set selection can have relatively low beam management overhead, allow relatively high rates and spectral efficiency, and result in relatively low power consumption. However, this type of set selection can also have an increased thermal gradient / temperature, relatively low robustness to polarization loss or multiple reflections / bounces, and relatively low robustness to beam blocking.

[0076] The second type of antenna element set can include patches of one polarization (HPol or VPol) and dipoles within the same band / carrier (e.g., patch 28HPol, dipole). This type of set selection can have relatively high beam - based diversity for blocking and polarization loss. However, this type of set selection can also have relatively high beam management overhead, higher power consumption, and can result in a higher temperature increase.

[0077] The third type of antenna element set can include patches of two orthogonal polarizations (HPol and VPol) across two bands / carriers (e.g., patch 28HPol, patch 39VPol). This type of set selection can have relatively low beam management overhead and can allow relatively high rates. However, this type of set selection can also have reduced spectral efficiency, result in a slightly increased power consumption, increase the thermal gradient, and have relatively low robustness to beam blocking or polarization loss.

[0078] The fourth type of antenna element set can include two patches of the same polarization (HPol or VPol) across multiple bands / carriers (e.g., patch 28HPol, patch 39HPol). This type of set selection can have relatively low beam management overhead, provide relatively high rates, and be relatively robust to polarization loss. However, this type of set selection can also have reduced spectral efficiency, have an increased thermal gradient, relatively low robustness to beam blocking, and result in a slightly increased power consumption.

[0079] As described above, the selection of one of the possible types of antenna element sets can have certain benefits and trade - offs. Thus, depending on which performance metric is most important to the UE during a given time period, the UE can select a preferred antenna element set. Depending on the operating conditions of the UE and the performance expectations determined by one or more applications at the UE, the relative priority of the performance metrics can change over time. The UE can be programmed with a fixed association table (e.g., stored in the UE's memory) that shows the preferred or desired combinations of antenna elements for specific performance metrics / objectives. Thus, the UE can determine a current priority list of performance metrics in order from high importance to low importance. Then the UE can use the relative priorities between the stored association table and the determined metrics to select the antenna element set that will most favorably satisfy the higher - priority performance metrics for the given conditions.

[0080] Figure 6 Shows the respective association mappings between performance metrics 602, 604, 606, 608, 610, 612, and 614 and antenna element sets 616, 618, 620, 622, and 624. For example, if performance metric 602 is the most important to the UE at a given time, then the UE can select one (or both) of antenna element sets 616 or 618 for the planned upcoming communication. In the case of multiple proposed antenna element sets for a particular performance metric, the UE can select multiple antenna element sets (in this example, both 616 and 618) to send to the base station as the preferred antenna element set. Alternatively, the UE can break ties (e.g., options of multiple possible sets) by considering second, third, fourth, or any other number of other performance metrics until a preferred set is determined. For example, if at a given time, performance metric 604 is the second - most important performance metric for the UE (after performance metric 602), then since antenna element set 618 matches both the first - and second - most important performance metrics, while antenna element set 616 only matches one of the metrics, the UE can select antenna element set 618 instead of antenna element set 616.

[0081] As another example, since the last antenna element set selection, during a subsequent time period, the operating conditions of the UE can change, and accordingly the most important performance metric for the UE can change. For example, during this time period, performance metric 612 can be the highest priority metric (e.g., above metric 602 which was the highest priority metric previously). Based on this change in performance metric priority over time, the UE can select antenna element set 622 as the preferred antenna element set for this time period based on the association of antenna element set 622 with performance metric 612. Depending on the UE's objectives and current operating conditions (e.g., the current conditions can be monitored by one or more sensors of the UE and other processing components of the UE), the UE can reorder the relative priorities of the performance metrics continuously or periodically over time. Thus, the preferred antenna element set can change over time following the change in the relative priorities between the performance metrics.

[0082] Figure 7 is a second example of a process for selecting one or more antenna element sets (e.g., selecting between antenna element sets 714, 716, or 718) based on one or more performance metrics (e.g., performance metrics 702, 704, 706, 708, 710, or 712). Performance metrics 702, 704, 706, 708, 710, or 712 can represent any performance or operating purpose / objective of the UE. Each of the following is as described above in connection with Figure 6 Performance metric 702 can represent a data rate metric, metric 704 can represent a power metric, metric 706 can represent a beam management metric, metric 708 can represent a robustness metric for polarization loss, metric 710 can represent a robustness metric for blockage, and 712 can represent a heat metric. In other implementations, the system can consider any number of performance metrics (e.g., more or fewer performance metrics than Figure 7 shown), and can select between any number of antenna element sets (e.g., more or fewer antenna element sets than Figure 7 shown, such as including different combinations of elements or adding antenna elements for additional frequency bands). In Figure 7 's example, certain performance metrics are associated with certain antenna element sets that can be used together for carrier aggregation communication such as inter-band carrier aggregation.

[0083] Figure 7 The antenna element set selection process of Figure 6In addition to the first, second, third, and fourth types of sets still being available, these fifth, sixth, and seventh types of sets can be used in systems with up to four RF chains. Each of these types of antenna element sets can have unique properties that bring various benefits or trade-offs.

[0084] The fifth type of antenna element set can include patches of two orthogonal polarizations (HPol and VPol) across two bands / carriers (e.g., patch 28HPol, patch 28VPol, patch 39HPol, patch 39VPol in the same module). This type of set selection can have a relatively high data rate, relatively low beam management overhead, and reduced power consumption. However, this type of set selection can also result in a higher temperature and have relatively low robustness to beam blocking and polarization loss.

[0085] The sixth type of antenna element set can include patches of two orthogonal polarizations (HPol and VPol) across one band / carrier in one module and across another band / carrier in a second module (e.g., patch 28HPol, patch 28VPol in module 1, and patch 39HPol, patch 39VPol in module 2). This type of set selection can result in a relatively low temperature (lower than other set selection options) and have relatively high robustness to beam blocking. However, this type of set selection can also achieve a relatively low rate, have relatively high beam management overhead, have relatively high power consumption, and have relatively low robustness to polarization loss.

[0086] The seventh type of antenna element set can include patches of two same polarizations (HPol) across two bands / carriers in one module and patches of different polarizations (VPol) across two bands / carriers in a second module (e.g., patch 28HPol, patch 39HPol in module 1, and patch 28VPol, patch 39VPol in module 2). This type of set selection can result in relatively high robustness to polarization loss and beam blocking and result in a relatively low temperature. However, this type of set selection can also achieve a relatively low rate, relatively high beam management overhead, and relatively high power consumption.

[0087] As described above, the selection of one of the possible types of antenna element sets can have certain benefits and trade - offs. Thus, depending on which performance metric is most important to the UE during a given time period, the UE can select a preferred antenna element set. Depending on the UE's operating conditions and performance expectations, the relative priorities of the performance metrics can change over time. The UE can be programmed with a fixed association table that shows the preferred or desired combinations of antenna elements for specific performance metrics / goals. Thus, the UE can determine a current priority list of performance metrics in order from highest importance to lowest importance. Then the UE can use the relative priorities between the metrics to select the antenna element set that will most favorably satisfy the higher - priority performance metrics.

[0088] Figure 7 Shows the respective association mappings between performance metrics 702, 704, 706, 708, 710, and 712 and antenna element sets 714, 716, and 718. For example, if performance metric 710 is the most important to the UE at a given time, then the UE can select one (or both) of antenna element sets 716 or 718. In the case of multiple proposed antenna element sets for a particular performance metric, the UE can select multiple antenna element sets (in this example, both 716 and 718) to send to the base station as the preferred antenna element set. Alternatively, the UE can break ties (e.g., options of multiple possible sets) by considering second, third, fourth, or any other number of other performance metrics until a preferred set is determined. For example, if performance metric 708 is the second - most important performance metric to the UE at a given time (after performance metric 610), then since antenna element set 716 matches both the first - most important and the second - most important performance metrics, while antenna element set 718 only matches one of the metrics, the UE can select antenna element set 716 instead of antenna element set 718.

[0089] As another example, since the last antenna element set selection, during a subsequent time period, the operating conditions of the UE can change (e.g., based on UE sensor data or other UE - processed data), and accordingly the performance metric that is most important to the UE can change. For example, during this time period, performance metric 704 can be the highest - priority metric (e.g., above metric 710, which had the highest priority previously). Based on this change in performance metric priority over time, the UE can select antenna element set 714 as the preferred antenna element set for this time period based on the association between antenna element set 714 and performance metric 704. Depending on the UE's goals and current operating conditions, the UE can re - order the relative priorities of the performance metrics continuously or periodically over time. Thus, the preferred antenna element set can change over time following the change in the relative priorities between the performance metrics.

[0090] Figure 8 is a flowchart illustrating an example of process 800 for sending an indication of antenna unit set selection for inter-band carrier aggregation communication. Process 800 may be performed by a wireless communication device such as a UE (e.g., Figure 1 UE 115, Figure 2 UE 115-a, Figure 3 device 305, or Figure 5 UE 500). In some implementations, features in the steps illustrated by process 800 may be performed by one or more components of a device such as Figure 3 device 305 as described. For example, the processing steps of process 800 may be performed by a processor 340 coupled to a memory 330, the memory 330 including instructions executable by the processor 340 to cause the device (e.g., UE) to perform the illustrated processing steps. As another example, the signal transmission and / or reception steps may be performed by a combination of one or more of a processor 340 (including instructions stored on the memory 330), a transceiver 320, RF chain components 315, and an antenna unit 325. Additionally or alternatively, the UE may use dedicated hardware to perform aspects of the functions described in process 800.

[0091] At step 802, the UE determines one or more performance metrics associated with the operation of the UE. The performance metric may include data regarding any one or more of the following: data transmission rate, power consumption, battery power level, spectral efficiency, beam management overhead, robustness to polarization loss, robustness to beam blockage, or thermal / temperature issues. Other implementations may consider additional types of performance metrics, fewer types of performance metrics, or different combinations or sub-combinations of performance metrics.

[0092] As a first example, the UE can determine a performance metric by comparing a measured data rate with a data rate threshold (e.g., to determine if the current data rate meets the data rate objective of the communication). As a second example, the UE can determine a performance metric by comparing a measured spectral efficiency with a spectral efficiency threshold (e.g., to determine if the current spectral efficiency meets the spectral efficiency objective of the communication). As a third example, the UE can determine a performance metric by comparing a measured power metric with a power threshold (e.g., to determine if the current battery power level is below a target level or if the power consumption level is above a target level). As a fourth example, the UE can determine a performance metric by comparing a measured heat metric with a heat threshold (e.g., to determine if the current operating temperature is above or below a target temperature level, such as a level that can indicate a desired temperature drop by throttling or turning off one or more components). As a fifth example, the UE can determine a performance metric by determining a priority level regarding robustness to polarization loss. As a sixth example, the UE can determine a performance metric by determining a priority level regarding robustness to blockage. As a seventh example, the UE can determine a performance metric by determining a priority level regarding the overhead associated with a beam management process. The UE can use any combination or sub - combination of these performance metrics, or as an alternative or addition to the examples listed, additional performance metrics can be considered.

[0093] In some implementations, when the UE determines one or more performance metrics, the UE determines a priority level associated with the one or more types of performance metrics. For example, as discussed in conjunction with Figure 6 and 7 , the UE can consider the current operating conditions and / or the current performance objectives and determine which type of performance metric consideration is relatively more important when selecting the set of antenna elements for inter - band carrier aggregation communication. For example, the UE can determine that for a first time period, a first type of performance metric has a higher priority than a second type of performance metric. Thus, when selecting which set of antenna elements should be selected for communication, the UE will take this relative priority into account. Some sets of antenna elements will be better suited than others to meet the performance objectives associated with the first type of performance metric. If the operating conditions or performance objectives change over time, then the UE can determine that the relative priority of the performance metrics has changed for a second time period. For example, for the second time period, the UE can determine that now the second type of performance metric has a higher priority than the first type of performance metric. Thus, when selecting which set of antenna elements should be selected for communication, the UE will take this change in relative priority (relative to the first time period) into account.

[0094] In step 804, the UE selects one or more antenna element sets from a plurality of antenna element sets available for inter-band carrier aggregation communication between the UE and one or more base stations across at least two radio frequency (RF) chains. The UE performs this selection in step 804 based at least in part on one or more performance metrics determined in step 802. For example, the UE may consider performance metrics such as the priority level associated with a particular metric and information indicating which antenna element set is favorable for a certain performance metric (e.g., the metric with the highest priority at that time or multiple relatively high-priority metrics at that time). Considering this performance metric information, the UE may select one or more antenna element sets based at least in part on the priority of one type of performance metric relative to another type of performance metric.

[0095] The selected antenna element set may include a single antenna element or may include multiple antenna elements. When the selected set includes multiple antenna elements, these antenna elements may be from a single antenna array, a single antenna module, multiple different antenna arrays, or multiple different antenna modules. The multiple antenna elements may be antenna elements of the same type or different types (e.g., patch or dipole), and of the same polarization or different polarizations (e.g., HPol or VPol). The multiple antenna elements may include antenna elements customized to operate in the same band or customized to operate in different bands. The selected antenna element set may include a first subset of antenna elements configured to operate in a first RF chain in a first frequency band and a second subset of antenna elements configured to operate in a second RF chain different from the first RF chain in a second frequency band different from the first frequency band. The first frequency band may be a component carrier or a bandwidth part (BWP) in a first millimeter wave band, and the second frequency band may be a component carrier or a BWP in a second millimeter wave band different from the first millimeter wave band. As another example, the selected antenna element set may include additional antenna elements configured to operate in an additional band (e.g., such that the total number of bands supported by the set reaches more than two bands).

[0096] The selected antenna element set may support communication from the UE to a single base station or multiple base stations. For example, when communicating with multiple base stations in inter-band carrier aggregation communication, the UE may use a first subset of the antenna elements in the selected set to communicate with a first base station within a first frequency band while using a second subset of the antenna elements in the selected set to communicate with a second base station within a second frequency band. The multiple base stations may be co-located (e.g., supported on the same tower or even within the same housing) or may be separated at different geographical locations (e.g., on different towers). The multiple base stations may be coordinated and controlled via a network-level high-speed interface (e.g., optical or fiber or backhaul link).

[0097] In step 806, the UE sends an indication of one or more selected antenna unit sets to one or more base stations. For inter-band carrier aggregation communication, the UE can be supported by one or more base stations. The UE can send a message indicating the preferred antenna unit set of the UE to a single base station, to a primary base station among multiple base stations that will participate in the communication, or to each of the multiple base stations that participate in the communication. The message includes an indication identifying the selected antenna unit set. The indication can include an identifier of a specific antenna unit (e.g., using an antenna unit index), an identifier of a specific antenna unit set (e.g., using a set index), an identifier of a beam corresponding to the selected antenna unit set (e.g., using a beam index), or any other way to explicitly or implicitly notify the base station of the selected antenna unit set by the UE.

[0098] The UE can send an indication of a single selected antenna unit set in step 806, or can send an indication of multiple selected antenna unit sets. When an indication of a single selected set is sent, the UE can signal to the receiving base station that the UE plans to use only this one set for the planned communication. Alternatively, when the UE sends an indication of multiple selected antenna unit sets, the UE can signal to the receiving base station that the UE is willing to use any one of the selected antenna unit sets for the planned communication. Then the base station can select among the provided set options, such as based on one or more network-level considerations (such as interference generated by one or more base stations, beam management overhead on the base station, base station priority, etc.). If the base station has a preference among the multiple options provided by the UE, then the base station can send back an indication of the base station-preferred antenna unit set to the UE. Then the UE can use the input from the base station to determine the selection of the antenna unit set for the planned communication.

[0099] Figure 9 is a flowchart showing an example of a process 900 for receiving an indication of antenna unit set selection for inter-band carrier aggregation communication. The process 900 can be performed by a communication device such as a base station (e.g., Figure 1 base station 105 of Figure 2 base station 105-a of Figure 4 or [[ID=Performed by one or more components of the described device 405. For example, the processing steps of process 900 can be performed by a processor 440 coupled to a memory 430, which includes instructions executable by the processor 440 to cause the device (e.g., a base station) to perform the described processing steps. As another example, the signal transmission and / or reception steps can be performed by a combination of one or more of the processor 440 (including instructions stored on the memory 430), a transceiver 420, an RF chain component 415, and an antenna unit 425. Additionally or alternatively, the base station can use dedicated hardware to perform aspects of the functions described in process 900.

[0100] In step 902, the base station receives an indication from the UE of one or more sets of antenna units of the UE selected for inter-band carrier aggregation communication between the UE and one or more base stations. The indication received in step 902 corresponds to the indication transmitted by the UE in step 806 ( ​ ).

[0101] In step 904, the base station selects at least a first base station beam based on the indication of the one or more sets of antenna units selected by the UE. In one example, the base station selects a communication beam for participating in inter-band carrier aggregation communication with the UE. The base station beam selected in step 904 can be used to transmit downlink data to the UE or receive uplink data from the UE. The base station can select a base station beam corresponding to at least one of the one or more sets of antenna units selected (and indicated to the base station in step 902) by the UE based on a desired beam link pair with the UE beamforming. In another example, the base station beam selected in step 904 is selected as a candidate beam for a beam training process to be used for inter-band carrier aggregation communication. The base station can select candidate base station beams to correspond to one or more UE beams likely to be used for planned inter-band carrier aggregation communication. Further details regarding the base station using the indication received in step 902 to focus the beam training process are discussed below in conjunction with ​ and 12 are discussed.

[0102] In step 906, the base station performs at least a part of the inter-band carrier aggregation communication between the UE and the base station using at least the first base station beam. In one example, the base station uses the selected base station beam to transmit data to the UE or receive data from the UE. In another example, the base station uses the selected base station beam to perform a beam training process as part of the inter-band carrier aggregation communication.

[0103] ​ is a message flow diagram of a process 1000 showing the selection of sets of antenna units for inter-band carrier aggregation communication. Process 1000 can be performed between a first wireless communication device and one or more second wireless communication devices. The first wireless communication device can be a UE (e.g.,​ UE 115, ​ UE 115-a, ​ device 305, or ​ UE 500), and the (multiple) second wireless communication devices can be base stations (e.g., ​ base station 105, ​ base station 105-a, or ​ device 405). In some implementations, the features shown in process 1000 can be performed by one or more components of device 305 (for UE actions) as described in ​ and one or more components of device 405 (for base station actions) as described in ​ . For example, the UE processing steps of process 1000 can be performed by a processor 340 coupled to a memory 330 that includes instructions executable by the processor 340 to cause the device (e.g., UE) to perform the described processing steps. For example, the base station processing steps of process 1000 can be performed by a processor 440 coupled to a memory 430 that includes instructions executable by the processor 440 to cause the device (e.g., base station) to perform the described processing steps. As another example, the UE signal transmission and / or reception steps can be performed by a combination of one or more of a processor 340 (including instructions stored on the memory 330), a transceiver 320, RF chain components 315, and an antenna unit 325. The base station signal transmission and / or reception steps can be performed by a combination of one or more of a processor 440 (including instructions stored on the memory 430), a transceiver 420, RF chain components 415, and an antenna unit 425. Additionally or alternatively, the UE or base station can use dedicated hardware to perform aspects of the functions described in process 1000.

[0104] In some implementations, ​ the base station 105 shown in ​ can represent a single base station, but in other implementations where the UE establishes inter-band carrier aggregation communication with multiple different base stations (co-located or at different geographical locations), it can represent multiple base stations. When communicating with multiple base stations, the UE can send ​ the messages shown in

[0105] In step 1002, the UE sends a capability notification to one or more base stations. The capability notification provides an indication of one or more inter-band carrier aggregation capabilities of the UE from the UE to one or more base stations. For example, one or more inter-band carrier aggregation capabilities of the UE may include an indication of the number of antenna modules at the UE, an indication of the limit on the number of RF chains allowed for each antenna module, or an indication of the limit on the number of RF chains allowed across all antenna modules on the UE. The base station may use this capability information to assist the UE in an antenna unit set selection process or to select an antenna unit set for the UE (e.g., considering other factors such as network-level considerations or UE performance metrics together with the base station). Some implementations may operate without the capability notification of step 1002 and may accordingly rely on the UE to select the desired antenna unit set and the base station to coordinate the final set selection, beam training optimization, and / or communication setup.

[0106] In step 1004, as discussed in more detail above in step 804 ( ​ ), the UE selects one or more antenna unit sets. In step 1006, as discussed in more detail above in step 806 ( ​ ), the UE notifies the base station of the antenna unit set selection. In step 1008, the base station may select one or more UE antenna unit sets. The base station's set selection in step 1008 may start from one or more set selections made by the UE and indicated in step 1006. For example, if the UE sends multiple possible sets that the UE considers acceptable, then the base station may select one of the UE antenna unit set options that the base station desires. For example, the UE may select an initial set based on UE factors or metrics, and the base station may reduce the list and select one or more sets from the initial set based on network factors or metrics. In step 1010, the base station may send an indication to the UE identifying the UE antenna unit set selected by the base station as being selected for inter-band carrier aggregation communication. As discussed above in connection with the UE set selection identification of step 806 ( ​ ), the base station may use a similar set identification scheme or nomenclature.

[0107] In step 1012, the base station may trigger a beam training process. For example, the base station may send a set of beam training reference signals to the UE. The UE may receive the beam training reference signals on a set of UE beams associated with at least one of the one or more selected antenna unit sets. In step 1014, in response to the set of beam training reference signals, the UE may send a beam training measurement report to the base station. The beam training measurement report may be based on measurements made by the UE on the received reference signals. For example, the UE may determine one or more beamforming metrics based on measurements made on the received reference signals.

[0108] In step 1016, the UE and one or more base stations establish and set up inter-band carrier aggregation communication by establishing a data link. In step 1018, the UE and the (multiple) base stations participate in inter-band carrier aggregation communication. The communication session is established and executed based on a set of antenna units negotiated between the UE and the base station. For example, the UE may use a set selected only by the UE, or a set selected based on an initial list of sets selected by the UE and then reduced to one or more sets based on base station input. During inter-band carrier aggregation communication, the UE may receive downlink communication using the selected set of antenna units, transmit uplink communication using the selected set of antenna units, or both.

[0109] In step 1020, the UE may identify a change in operating conditions or performance objectives that results in a change in the monitored performance metric. The UE may continuously monitor the performance metric, periodically monitor the performance metric, or monitor the performance metric based on a trigger event (or randomly). Then, as discussed in connection with ​ and 7 (and ​ step 802 of ​ and 7 (and ​ step 804 of ​ ), the current or updated performance metric may be evaluated or prioritized. In step 1022, as discussed in connection with

[0110] ​ ​ and 7 (and ​ step 804 of ​ ), the UE uses the most recent performance metric (e.g., the relative priority between metrics) to select a desired one or more sets of UE antenna units. For example, the UE may determine that a second type of performance metric has a higher priority than a first type of performance metric for the current time period (whereas the first type of metric was of higher priority for the first time period). Based on this change in the priority between performance metrics, for the second time period the UE may select one or more different sets of antenna units (different from the set of antenna units used for the first time period) and, in step 1024, send an indication of the one or more different sets of antenna units from the UE to one or more base stations (as discussed in more detail above in step 806( ​ ). In step 1026, the UE and the base station participate in inter-band carrier aggregation communication based on the most recently selected (multiple) set of antenna units.

[0110] ​This is the first example of the beam training process between the UE and the base station. After the UE selects one or more antenna element sets for inter-band carrier aggregation communication and notifies the base station of the selected antenna element sets preferred on the UE side, the base station can then use this information to focus its beam training process on the relevant UE-side beams. For example, the base station can determine that the UE has selected an antenna element set from the first antenna module of the UE and has not identified any antenna element sets that include antenna elements from other antenna modules of the UE. In this case, the base station can focus its beam training process on the UE beam corresponding to the antenna module that supports the selected antenna element set. In ​ In the example of ​ , the base station can focus its base station beam 1102 on the beam 1104 associated with the module that includes the selected antenna element set. By focusing on the beam 1104 associated with the module that includes the selected antenna element set, the base station can skip performing the beam training process on other beams of the UE, such as beams 1106 and 1108. For example, for this beam training process, the base station can send a beam training reference signal to beam 1104, but not to beams 1106 and 1108. Compared with the full beam scanning process that covers all beams, this focused beam training process can save time and power.

[0111] In a specific example, based on the indication of one or more antenna element sets selected by the UE, the base station can determine that the first antenna array among the multiple antenna arrays of the UE will be used by the UE for inter-band carrier aggregation communication on the first RF chain. Based on the indication of one or more antenna element sets selected by the UE, the base station can also determine that the second antenna array among the multiple antenna arrays of the UE will be used by the UE for inter-band carrier aggregation communication on the second RF chain. Then, based on the determination that the first antenna array and the second antenna array will be used by the UE for inter-band carrier aggregation communication, the base station can focus its beam training process on one or more UE beams corresponding to the first antenna array and one or more UE beams corresponding to the second antenna array. By performing the beam training process without performing beam training on one or more UE beams corresponding to one or more other antenna arrays among the multiple antenna arrays, the base station can focus its beam training process.

[0112] By focusing the beam training process on the UE beams associated with the selected UE antenna element sets, the base station can reduce the exhaustive beam training time associated with checking all beam pairs between the base station and the UE on all sub-arrays. By focusing the set of target beam pairs to be used for selecting a specific set (on the UE side) for planned communication, the base station can use the set selection information of the UE to reduce the beam training time.

[0113] ​This is the second example of the beam training process between the UE and the base station. After the UE selects one or more sets of antenna units for inter-band carrier aggregation communication and notifies the base station of the selected set of antenna units preferred on the UE side, the base station can then use this information to focus its beam training process on the relevant UE-side beams and base-station-side beams. For example, the base station can determine that the UE has selected a set of antenna units from the first antenna module of the UE and has not identified any set of antenna units that includes antenna units from other antenna modules of the UE. In this case, the base station can focus its beam training process on the base-station beams and UE beams corresponding to the specific set(s) of antenna units selected by the UE. In ​ In the example of ​ , the base station can focus the beam training process on a sub-part of its base-station beams and a sub-part of the UE beams. For example, since base-station beam 1204 and UE beam 1210 are the beams associated with the selected set of antenna units, the base station can focus on base-station beam 1204 and UE beam 1210. By focusing on base-station beam 1204 and UE beam 1210, which are the base-station and UE beams most likely to be associated with the selected set of antenna units, the base station can skip performing the beam training process on other base-station and UE beams (such as beams 1202, 1206, 1208, 1212, 1214, and 1216). For example, for this beam training process, the base station can send a beam training reference signal from base-station beam 1204 to UE beam 1210, but not from other base-station beams (1202 and 1206) or to other UE beams (1208, 1212, 1214, and 1216). Compared with the full beam scanning process that covers all beams, this focused beam training process can save time and power. In one example, when performing the beam training process that will be focused on the beams associated with the selected UE antenna unit set for this specific communication, the base station can disable base-station beams 1202 and 1206.

[0114] The various illustrative components, logics, logic blocks, modules, circuits, operations, and algorithmic processes described in conjunction with the implementations disclosed herein can be implemented as electronic hardware, firmware, software, or any combination of hardware, firmware, or software, including the structures disclosed in this specification and their structural equivalents. The interchangeability of hardware, firmware, and software has been generally described in terms of functionality and is illustrated in the various illustrative components, blocks, modules, circuits, and processes described above. Whether these functions are implemented as hardware, firmware, or software depends on the particular application and the design constraints imposed on the overall system.

[0115] The hardware and data processing apparatus for implementing the various illustrative components, logic, logic blocks, modules, and circuits described in connection with the aspects disclosed herein can be implemented or performed by a general-purpose single- or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processor can be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some implementations, specific processes, operations, and methods can be performed by circuitry tailored for a given function.

[0116] As described above, in some aspects, implementations of the subject matter described in this specification can be implemented as software. For example, the various functions of the components disclosed herein, or the various blocks or steps of the methods, operations, processes, or algorithms disclosed herein, can be implemented as one or more modules of one or more computer programs. Such a computer program can include non-transitory processor or computer-executable instructions encoded on one or more tangible processor or computer-readable storage media for execution by a data processing apparatus, or for execution to control the operation of a data processing apparatus, which includes the components of the devices described herein. By way of example, and not limitation, such storage media can include RAM, ROM, EEPROM, CD-ROM, or other optical disk storage, magnetic disk storage, or other magnetic storage devices, or any other medium that can be used to store program code in the form of instructions or data structures. Combinations of the above should also be included within the scope of storage media.

[0117] It will be apparent to those skilled in the art that various modifications to the implementations described in this disclosure can be made, and the general principles defined herein can be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the implementations shown herein, but are to be accorded the widest scope consistent with this disclosure, the principles, and the novel features disclosed herein.

[0118] In addition, the features described in the specification in the context of different implementation manners can also be implemented in a combination of a single implementation manner. Conversely, the features described in the context of a single implementation manner can also be implemented separately or in any suitable sub-combination in multiple implementation manners. Thus, although a feature may be described above as occurring in a particular combination and even initially claimed, one or more features from the claimed combination may in some cases be deleted from that combination, and the claimed combination may be directed to a sub-combination or a variation of a sub-combination.

[0119] Similarly, although operations are depicted in the figures in a particular order, this should not be construed as requiring that the operations be performed in the particular order shown or in sequential order, or that all of the operations shown need to be performed to achieve the desired result. Further, the drawings schematically depict one or more example processes in the form of a flowchart or a flow diagram. However, other operations not depicted may be incorporated into the example processes schematically shown. For example, one or more additional operations may be performed before, after, concurrently with, or between any of the operations shown. In some environments, multitasking and parallel processing may be advantageous. In addition, separating the various system components in the implementation manners described above should not be construed as requiring such separation in all implementation manners, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

[0120] It should be understood that the use of terms such as "first", "second", etc. to refer to elements herein generally does not limit the number or order of those elements. On the contrary, these terms are used herein as a convenient method for distinguishing between two or more elements or instances of elements. Thus, the reference to a first and a second element does not mean that only two elements can be used there, or that the first element must in some way precede the second element. Similarly, unless otherwise indicated, a set of elements may include one or more elements. In addition, a term of the form "at least one of A, B, or C" or "one or more of A, B, or C" or "at least one of the group consisting of A, B, and C" used in the specification or claims means "A or B or C or any combination of these elements". For example, the term may include A, or B, or C, or A and B, or A and C, or A and B and C, or 2A, or 2B, or 2C, etc. In addition, although certain aspects may be described or claimed in the singular, the plural is contemplated unless explicitly limited to the singular.

Claims

1. A method for wireless communication at a user equipment (UE), comprising: Determining one or more performance metrics associated with an operation of the UE; The UE selecting, at least in part based on the one or more performance metrics, one or more antenna element sets from a plurality of antenna element sets available for inter-band carrier aggregation communication between the UE and one or more base stations across at least two radio frequency (RF) chains; And Sending an indication of the one or more selected antenna element sets from the UE to the one or more base stations; Performing at least a part of the inter-band carrier aggregation communication between the UE and the one or more base stations using a first antenna element set selected from the one or more selected antenna element sets, Wherein performing the at least a part of the inter-band carrier aggregation communication includes receiving downlink communication using the first antenna element set, transmitting uplink communication using the first antenna element set, or both; Wherein the first antenna element set includes a first subset of antenna elements configured to operate in a first RF chain in a first frequency band, and a second subset of antenna elements configured to operate in a second RF chain different from the first RF chain in a second frequency band different from the first frequency band; And Communicating with a first base station among the one or more base stations within the first frequency band using the first subset of antenna elements, while communicating with a second base station among the one or more base stations within the second frequency band using the second subset of antenna elements.

2. The method according to claim 1, further comprising receiving, at the UE, from at least one of the one or more base stations, an indication identifying the first antenna element set as being selected for the inter-band carrier aggregation communication.

3. The method according to claim 1, wherein the first frequency band includes a component carrier or a bandwidth part in a first millimeter wave band, and the second frequency band includes a component carrier or a bandwidth part in a second millimeter wave band different from the first millimeter wave band.

4. The method according to claim 1, further comprising sending, from the UE to the one or more base stations, a capability indication regarding one or more inter-band carrier aggregation capabilities of the UE.

5. The method according to claim 4, wherein the one or more inter-band carrier aggregation capabilities of the UE include an indication of the number of antenna modules at the UE, an indication of a limit on the number of RF chains allowed for each antenna module, or a limit on the number of RF chains allowed across all antenna modules at the UE.

6. The method according to claim 1, further comprising: Receiving, at the UE, from at least one of the one or more base stations, a set of beam training reference signals on a UE beam set associated with at least one of the one or more selected antenna element sets; And Sending, in response to the set of beam training reference signals, a beam training measurement report from the UE to the at least one of the one or more base stations.

7. The method according to claim 1, wherein determining the one or more performance metrics comprises: Determining that for a first time period, a first type of performance metric has a higher priority than a second type of performance metric; And Selecting the one or more antenna unit sets includes: selecting the one or more antenna unit sets for the first time period at least partially based on the priority that the performance metric of the first type is higher than the performance metric of the second type.

8. The method according to claim 7, further comprising: Determining that for a second time period, the performance metric of the second type has a higher priority than the performance metric of the first type; Selecting one or more different antenna unit sets for the second time period at least partially based on the priority that the performance metric of the second type is higher than the performance metric of the first type; And Sending an indication of the one or more different antenna unit sets from the UE to the one or more base stations.

9. The method according to claim 1, wherein determining the one or more performance metrics includes at least one of the following: Comparing a measured rate with a rate threshold; Comparing a measured spectral efficiency with a spectral efficiency threshold; Comparing a measured power metric with a power threshold; or Comparing a measured heat metric with a heat threshold.

10. The method according to claim 1, wherein determining the one or more performance metrics includes at least one of the following: Determining a priority level regarding robustness to polarization loss; Determining a priority level regarding robustness to blockage; or Determining a priority level regarding overhead associated with a beam management process.

11. A method for wireless communication at a base station, comprising: Receiving, at the base station, an indication of one or more antenna unit sets of a user equipment (UE) selected by the UE for inter-band carrier aggregation communication between the UE and one or more base stations; Selecting at least a first base station beam based on the indication of the one or more antenna unit sets selected by the UE; Performing at least a part of the inter-band carrier aggregation communication between the UE and the base station using at least the first base station beam; Determining, based on the indication of the one or more antenna unit sets selected by the UE, that a first antenna array among a plurality of antenna arrays of the UE will be used by the UE for the inter-band carrier aggregation communication on a first RF chain; Determining, based on the indication of the one or more antenna unit sets selected by the UE, that a second antenna array among the plurality of antenna arrays of the UE will be used by the UE for the inter-band carrier aggregation communication on a second RF chain; And Based on the determination that the first antenna array will be used by the UE for the inter-band carrier aggregation communication on the first RF chain and the determination that the second antenna array will be used by the UE for the inter-band carrier aggregation communication on the second RF chain, concentrating a beam training process on one or more UE beams corresponding to the first antenna array and the second antenna array.

12. The method according to claim 11, further comprising: Selecting a first antenna unit set from the one or more antenna unit sets of the UE selected by the UE; And Send an indication from the base station to the UE identifying the first antenna element set as being selected for the inter-band carrier aggregation communication.

13. The method according to claim 11, wherein concentrating the beam training process on the one or more UE beams corresponding to the first antenna array and the second antenna array comprises: Perform the beam training process without performing beam training on one or more UE beams corresponding to one or more other antenna arrays among the plurality of antenna arrays.

14. The method according to claim 11, further comprising: Based on the indication of the one or more antenna element sets selected by the UE, select a first subset of a plurality of available base station beams, wherein the first subset includes the first base station beam; And Based on the indication of the one or more antenna element sets selected by the UE, concentrate the beam training process on the first subset of the plurality of available base station beams.

15. The method according to claim 14, wherein concentrating the beam training process on the first subset comprises: Perform the beam training process without performing beam training on a second subset of the plurality of available base station beams.

16. A user equipment (UE) for wireless communication, comprising: A processor; And A memory coupled to the processor, wherein the memory includes instructions executable by the processor to cause the UE to perform the following operations: Determine one or more performance metrics associated with the operation of the UE; At least partially based on the one or more performance metrics, select one or more antenna element sets from a plurality of antenna element sets available for inter-band carrier aggregation communication between the UE and one or more base stations across at least two radio frequency (RF) chains; And Send an indication of the one or more selected antenna element sets from the UE to the one or more base stations; Use a first antenna element set selected from the one or more selected antenna element sets to perform at least a part of the inter-band carrier aggregation communication between the UE and the one or more base stations, Wherein performing the at least a part of the inter-band carrier aggregation communication includes receiving downlink communication using the first antenna element set, transmitting uplink communication using the first antenna element set, or both; Wherein the first antenna element set includes a first subset of antenna elements configured to operate in a first RF chain in a first frequency band, and a second subset of antenna elements configured to operate in a second RF chain different from the first RF chain in a second frequency band different from the first frequency band; And Use the first subset of antenna elements to communicate with a first base station among the one or more base stations within the first frequency band, while using the second subset of antenna elements to communicate with a second base station among the one or more base stations within the second frequency band.

17. The UE according to claim 16, wherein the memory includes instructions executable by the processor to cause the UE to send, from the UE to the one or more base stations, an ability indication regarding one or more inter-band carrier aggregation capabilities of the UE, wherein the one or more inter-band carrier aggregation capabilities of the UE include an indication of the number of antenna modules at the UE, an indication of a limit on the number of RF chains allowed for each antenna module, or an indication of a limit on the number of RF chains allowed across all antenna modules at the UE.

18. The UE according to claim 16, wherein the instructions executable by the processor to cause the UE to determine the one or more performance metrics include instructions executable by the processor that cause the UE to determine that, for a first time period, a first type of performance metric has a higher priority than a second type of performance metric; and wherein the instructions executable by the processor to cause the UE to select the one or more antenna unit sets include instructions executable by the processor that cause the UE to select, for the first time period, the one or more antenna unit sets at least in part based on the priority that the first type of performance metric is higher than the second type of performance metric.

19. The UE according to claim 18, wherein the memory includes instructions executable by the processor to cause the UE to perform the following operations: Determine that, for a second time period, the second type of performance metric has a higher priority than the first type of performance metric; Select, at least in part based on the priority that the second type of performance metric is higher than the first type of performance metric, one or more different antenna unit sets for the second time period; And Send an indication of the one or more different antenna unit sets from the UE to the one or more base stations.

20. The UE according to claim 16, wherein the instructions executable by the processor to cause the UE to determine the one or more performance metrics include instructions executable by the processor that cause the UE to perform the following operations: Compare a measured rate with a rate threshold; Compare a measured spectral efficiency with a spectral efficiency threshold; Compare a measured power metric with a power threshold; or Compare a measured heat metric with a heat threshold.

21. The UE according to claim 16, wherein the instructions executable by the processor to cause the UE to determine the one or more performance metrics include instructions executable by the processor to cause the UE to perform the following operations: Determine a priority level regarding robustness to polarization loss; Determine a priority level regarding robustness to blockage; or Determine a priority level regarding the overhead associated with a beam management process.

22. A base station for wireless communication, comprising: A processor; And A memory coupled to the processor, wherein the memory includes instructions executable by the processor to cause the base station to perform the following operations: Receive an indication of one or more sets of antenna units of the UE selected by the UE for inter-band carrier aggregation communication between the UE and one or more base stations from the user equipment UE; Select at least a first base station beam based on the indication of the one or more sets of antenna units selected by the UE; Perform at least a part of the inter-band carrier aggregation communication between the UE and the base station using at least the first base station beam; Determine that a first antenna array among a plurality of antenna arrays of the UE will be used by the UE for the inter-band carrier aggregation communication on a first RF chain based on the indication of the one or more sets of antenna units selected by the UE; Determine that a second antenna array among the plurality of antenna arrays of the UE will be used by the UE for the inter-band carrier aggregation communication on a second RF chain based on the indication of the one or more sets of antenna units selected by the UE; And Based on the determination that the first antenna array will be used by the UE for the inter-band carrier aggregation communication on the first RF chain and the determination that the second antenna array will be used by the UE for the inter-band carrier aggregation communication on the second RF chain, concentrate a beam training process on one or more UE beams corresponding to the first antenna array and the second antenna array without performing beam training on one or more UE beams corresponding to one or more other antenna arrays among the plurality of antenna arrays.

23. The base station according to claim 22, wherein the memory includes instructions executable by the processor to cause the base station to perform the following operations: Select a first subset of a plurality of available base station beams based on the indication of the one or more sets of antenna units selected by the UE, wherein the first subset includes the first base station beam; and Based on the indication of the one or more sets of antenna units selected by the UE, concentrate a beam training process on the first subset of the plurality of available base station beams without performing beam training on a second subset of the plurality of available base station beams.

24. A non-transitory computer-readable storage medium storing instructions for wireless communication to be executed by a user equipment UE, the instructions causing a processor to perform the following operations: Determine one or more performance metrics associated with the operation of the UE; Select, by the UE at least partially based on the one or more performance metrics, one or more sets of antenna units from a plurality of sets of antenna units available for inter-band carrier aggregation communication between the UE and one or more base stations across at least two radio frequency RF chains; And Transmit an indication of the one or more selected sets of antenna units from the UE to the one or more base stations; Perform at least a part of the inter-band carrier aggregation communication between the UE and the one or more base stations using a first selected set of antenna units selected from the one or more selected sets of antenna units, Performing at least a portion of the inter-band carrier aggregation communication includes receiving downlink communication using the first set of antenna units, transmitting uplink communication using the first set of antenna units, or both; The first set of antenna units includes a first subset of antenna units configured to operate in a first RF chain in a first frequency band and a second subset of antenna units configured to operate in a second RF chain different from the first RF chain in a second frequency band different from the first frequency band; And Communicating with a first base station among the one or more base stations within the first frequency band using the first subset of antenna units while communicating with a second base station among the one or more base stations within the second frequency band using the second subset of antenna units.

25. A non-transitory computer-readable storage medium storing instructions for wireless communication to be performed by a base station, the instructions causing a processor to perform the following operations: Receiving, at the base station, an indication of one or more sets of antenna units of the UE selected by the UE for inter-band carrier aggregation communication between the UE and one or more base stations; Selecting at least a first base station beam based on the indication of the one or more sets of antenna units selected by the UE; And Performing at least a portion of the inter-band carrier aggregation communication between the UE and the base station using at least the first base station beam; Determining, based on the indication of the one or more sets of antenna units selected by the UE, that a first antenna array among a plurality of antenna arrays of the UE will be used by the UE for the inter-band carrier aggregation communication on a first RF chain; Determining, based on the indication of the one or more sets of antenna units selected by the UE, that a second antenna array among the plurality of antenna arrays of the UE will be used by the UE for the inter-band carrier aggregation communication on a second RF chain; And Based on the determination that the first antenna array will be used by the UE for the inter-band carrier aggregation communication on the first RF chain and the determination that the second antenna array will be used by the UE for the inter-band carrier aggregation communication on the second RF chain, concentrating a beam training process on one or more UE beams corresponding to the first antenna array and the second antenna array.

26. An apparatus for wireless communication at a user equipment (UE), the apparatus comprising: Means for determining one or more performance metrics associated with the operation of the UE; Means for the UE to select, at least in part based on the one or more performance metrics, one or more sets of antenna units from a plurality of sets of antenna units available for inter-band carrier aggregation communication between the UE and one or more base stations across at least two radio frequency (RF) chains; And Means for sending an indication of the one or more selected sets of antenna units from the UE to the one or more base stations; Components for performing at least a portion of the inter-band carrier aggregation communication between the UE and the one or more base stations using a first set of antenna units selected from the one or more selected sets of antenna units, where performing at least a portion of the inter-band carrier aggregation communication includes receiving downlink communication using the first set of antenna units, transmitting uplink communication using the first set of antenna units, or both; where the first set of antenna units includes a first subset of antenna units configured to operate in a first RF chain in a first frequency band and a second subset of antenna units configured to operate in a second RF chain in a second frequency band different from the first frequency band; and Components for communicating with a first base station among the one or more base stations within the first frequency band using the first subset of antenna units while communicating with a second base station among the one or more base stations within the second frequency band using the second subset of antenna units.

27. An apparatus for wireless communication at a base station, the apparatus comprising: Components for receiving, at the base station, an indication of one or more sets of antenna units of the UE selected by the UE for inter-band carrier aggregation communication between the UE and one or more base stations; Components for selecting at least a first base station beam based on the indication of the one or more sets of antenna units selected by the UE; and Components for performing at least a portion of the inter-band carrier aggregation communication between the UE and the base station using at least the first base station beam; Components for determining, based on the indication of the one or more sets of antenna units selected by the UE, that a first antenna array among the multiple antenna arrays of the UE will be used by the UE for inter-band carrier aggregation communication on a first RF chain; Components for determining, based on the indication of the one or more sets of antenna units selected by the UE, that a second antenna array among the multiple antenna arrays of the UE will be used by the UE for inter-band carrier aggregation communication on a second RF chain; and Components for focusing a beam training process onto one or more UE beams corresponding to the first antenna array and the second antenna array based on the determination that the first antenna array will be used by the UE for inter-band carrier aggregation communication on a first RF chain and the determination that the second antenna array will be used by the UE for inter-band carrier aggregation communication on a second RF chain.

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