Patent Publication Number: US-2023156627-A1

Title: Multi-panel power reporting techniques

Description:
CROSS REFERENCE 
     The present application is a 371 national stage filing of International PCT Application No. PCT/CN2020/094543 by YUAN et al. entitled “MULTI-PANEL POWER REPORTING TECHNIQUES,” filed Jun. 5, 2020, which is assigned to the assignee hereof, and which is expressly incorporated by reference in its entirety herein. 
    
    
     FIELD OF TECHNOLOGY 
     The following relates generally to wireless communications and more specifically to multi-panel power reporting techniques. 
     BACKGROUND 
     Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies 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 multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE). 
     A UE may communicate with a base station in a wireless communications system, for example, using one or more uplink transmissions. In some cases, conventional techniques for power management at the UE may be deficient. For example, the UE may be unable to accurately report a power usage for uplink transmissions, which may result in relatively poor power management or inefficient communications in the system. 
     SUMMARY 
     The described techniques relate to improved methods, systems, devices, and apparatuses that support multi-panel power reporting techniques. Generally, the described techniques provide for multi-panel power headroom reports in a wireless communications system, which may enable devices in a system to accurately indicate power capabilities, more efficiently schedule communications, or enhance power management, among other benefits. For example, a user equipment (UE) may communicate with a base station using multiple panels (e.g., a first panel and a second panel). The UE may determine one or more panel specific power headroom values. For example, the UE may calculate a first power headroom value for the first panel. The UE may additionally or alternatively calculate a second power headroom value for the second panel. The UE may transmit a power headroom report indicating the one or more panel specific power headroom values. In some examples, the UE may transmit the power headroom report based on identifying that one or more thresholds associated with the power headroom report are satisfied. For example, the UE may determine that a timer associated with the power headroom report has expired, that one or more power backoff metrics satisfy one or more thresholds, that a medium access control (MAC) entity has uplink resources for an uplink transmission, or any combination thereof. In some examples, the power headroom report may include one or more fields indicating the panel specific power headroom values, whether the first power headroom value for the first panel is included in the report, whether the second power headroom value for the second panel is included in the report, or any combination thereof, among other examples of fields as described herein. 
     A method of wireless communications at a UE is described. The method may include communicating via a first panel of the UE and a second panel of the UE, determining at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel, and transmitting, to a base station, a report indicating at least one of the first power headroom value for the first panel or the second power headroom value for the second panel. 
     An apparatus for wireless communications at a UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to communicate via a first panel of the UE and a second panel of the UE, determine at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel, and transmit, to a base station, a report indicating at least one of the first power headroom value for the first panel or the second power headroom value for the second panel. 
     Another apparatus for wireless communications at a UE is described. The apparatus may include means for communicating via a first panel of the UE and a second panel of the UE, determining at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel, and transmitting, to a base station, a report indicating at least one of the first power headroom value for the first panel or the second power headroom value for the second panel. 
     A non-transitory computer-readable medium storing code for wireless communications at a UE is described. The code may include instructions executable by a processor to communicate via a first panel of the UE and a second panel of the UE, determine at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel, and transmit, to a base station, a report indicating at least one of the first power headroom value for the first panel or the second power headroom value for the second panel. 
     A method of wireless communications at a base station is described. The method may include communicating with a first panel of a UE and a second panel of the UE and receiving, from the UE, a report indicating at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel. 
     An apparatus for wireless communications at a base station is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to communicate with a first panel of a UE and a second panel of the UE and receive, from the UE, a report indicating at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel. 
     Another apparatus for wireless communications at a base station is described. The apparatus may include means for communicating with a first panel of a UE and a second panel of the UE and receiving, from the UE, a report indicating at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel. 
     A non-transitory computer-readable medium storing code for wireless communications at a base station is described. The code may include instructions executable by a processor to communicate with a first panel of a UE and a second panel of the UE and receive, from the UE, a report indicating at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates an example of a system for wireless communications that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. 
         FIG.  2    illustrates an example of a wireless communications system that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. 
         FIG.  3    illustrates examples of resource schemes that support multi-panel power reporting techniques in accordance with aspects of the present disclosure. 
         FIG.  4    illustrates examples of wireless communications systems that support multi-panel power reporting techniques in accordance with aspects of the present disclosure. 
         FIG.  5    illustrates an example of a process flow that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. 
         FIGS.  6  and  7    show block diagrams of devices that support multi-panel power reporting techniques in accordance with aspects of the present disclosure. 
         FIG.  8    shows a block diagram of a communications manager that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. 
         FIG.  9    shows a diagram of a system including a device that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. 
         FIGS.  10  and  11    show block diagrams of devices that support multi-panel power reporting techniques in accordance with aspects of the present disclosure. 
         FIG.  12    shows a block diagram of a communications manager that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. 
         FIG.  13    shows a diagram of a system including a device that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. 
         FIGS.  14  through  17    show flowcharts illustrating methods that support multi-panel power reporting techniques in accordance with aspects of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Some wireless communications systems may support multi-panel communications between a user equipment (UE) and a base station. As an illustrative example, the UE may use a first panel for uplink transmissions to the base station, a second panel for uplink transmissions to a base station, etc. In some conventional systems, a UE may transmit a power headroom report (PHR) to a base station which indicates the difference between the maximum transmit power and the currently used transmit power at the UE. However, different panels may be associated with different power usages, channel conditions, etc. For example, a first panel of the UE may experience a maximum permissible exposure (MPE) event (e.g., a person may be within a threshold power exposure for a transmission using the first panel) and the power of the first panel may be reduced. Conventional power headroom reporting techniques do not consider power management of multiple panels (e.g., the reports may indicate a power headroom of the UE as a whole). Such techniques may result in relatively poor system performance. For example, the UE may be unable to accurately report power headroom values for different panels or the base station may be unaware of the MPE event, which may result in inefficient communications or relatively poor power management (e.g., the base station may schedule data above a threshold of the reduced power for the first panel, the base station may fail to allocate resources to a second panel capable of using more power, among other examples). 
     In accordance with the techniques described herein, a wireless communications system may implement multi-panel power headroom reports for communications between device, which may enable the devices to accurately indicate power capabilities, more efficiently schedule communications, or enhance power management, among other benefits. For example, a UE may communicate with a base station using a first panel and a second panel (e.g., a first antenna panel and a second antenna panel). The UE may determine one or more panel specific power headroom values to report to the base station. For example, the UE may calculate a first power headroom value for the first panel (e.g., based on one or more panel specific parameters, such as a maximum transmit power parameter associated with the first panel, a maximum power reduction parameter associated with the first panel, etc.). Additionally or alternatively, the UE may calculate a second power headroom value for the second panel (e.g., using one or more panel specific parameters, such as a maximum transmit power parameter associated with the second panel, a maximum power reduction parameter associated with the second panel, etc.). 
     The UE may transmit a power headroom report indicating the one or more panel specific power headroom values. In some examples, the UE may transmit the power headroom report based on identifying that one or more thresholds associated with the power headroom report are satisfied. For example, the UE may determine that a timer associated with the power headroom report has expired, that one or more power backoff metrics satisfy one or more thresholds (e.g., a change in a power backoff metric for the first panel, the second panel, or both may satisfy a change threshold), that a medium access control (MAC) entity has uplink resources for an uplink transmission, or any combination thereof. The power headroom report may include one or more fields indicating the panel specific power headroom values. For example, the UE may populate one or more fields of the report, the one or more fields indicating whether the first power headroom value for the first panel is included in the report, whether the second power headroom value for the second panel is included in the report, whether a MAC entity applies power management techniques, whether a panel specific power headroom value is based on a real transmission format or a virtual transmission format, or any combination thereof, among other examples of fields. 
     Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are then described in the context of resource schemes and process flows. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to multi-panel power reporting techniques. 
       FIG.  1    illustrates an example of a wireless communications system  100  that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. The wireless communications system  100  may include one or more base stations  105 , one or more UEs  115 , and a core network  130 . In some examples, the wireless communications system  100  may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communications system  100  may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof. 
     The base stations  105  may be dispersed throughout a geographic area to form the wireless communications system  100  and may be devices in different forms or having different capabilities. The base stations  105  and the UEs  115  may wirelessly communicate via one or more communication links  125 . Each base station  105  may provide a coverage area  110  over which the UEs  115  and the base station  105  may establish one or more communication links  125 . The coverage area  110  may be an example of a geographic area over which a base station  105  and a UE  115  may support the communication of signals according to one or more radio access technologies. 
     The UEs  115  may be dispersed throughout a coverage area  110  of the wireless communications system  100 , and each UE  115  may be stationary, or mobile, or both at different times. The UEs  115  may be devices in different forms or having different capabilities. Some example UEs  115  are illustrated in  FIG.  1   . The UEs  115  described herein may be able to communicate with various types of devices, such as other UEs  115 , the base stations  105 , or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment), as shown in  FIG.  1   . 
     The base stations  105  may communicate with the core network  130 , or with one another, or both. For example, the base stations  105  may interface with the core network  130  through one or more backhaul links  120  (e.g., via an S1, N2, N3, or other interface). The base stations  105  may communicate with one another over the backhaul links  120  (e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations  105 ), or indirectly (e.g., via core network  130 ), or both. In some examples, the backhaul links  120  may be or include one or more wireless links. 
     One or more of the base stations  105  described herein may include or may be referred to by a person having ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or a giga-NodeB (either of which may be referred to as a gNB), a Home NodeB, a Home eNodeB, or other suitable terminology. 
     A UE  115  may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client, among other examples. A UE  115  may also include or may be referred to as 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  may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which may be implemented in various objects such as appliances, or vehicles, meters, among other examples. 
     The UEs  115  described herein may be able to communicate with various types of devices, such as other UEs  115  that may sometimes act as relays as well as the base stations  105  and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in  FIG.  1   . 
     The UEs  115  and the base stations  105  may wirelessly communicate with one another via one or more communication links  125  over one or more carriers. The term “carrier” may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication links  125 . For example, a carrier used for a communication link  125  may include a portion of a radio frequency spectrum band (e.g., a bandwidth part (BWP)) that is operated according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling that coordinates operation for the carrier, user data, or other signaling. The wireless communications system  100  may support communication with a UE  115  using carrier aggregation or multi-carrier operation. A UE  115  may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both frequency division duplexing (FDD) and time division duplexing (TDD) component carriers. 
     In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers. A carrier may be associated with a frequency channel (e.g., an evolved universal mobile telecommunication system terrestrial radio access (E-UTRA) absolute radio frequency channel number (EARFCN)) and may be positioned according to a channel raster for discovery by the UEs  115 . A carrier may be operated in a standalone mode where initial acquisition and connection may be conducted by the UEs  115  via the carrier, or the carrier may be operated in a non-standalone mode where a connection is anchored using a different carrier (e.g., of the same or a different radio access technology). 
     The communication links  125  shown in the wireless communications system  100  may include uplink transmissions from a UE  115  to a base station  105 , or downlink transmissions from a base station  105  to a UE  115 . Carriers may carry downlink or uplink communications (e.g., in an FDD mode) or may be configured to carry downlink and uplink communications (e.g., in a TDD mode). 
     A carrier may be associated with a particular bandwidth of the radio frequency spectrum, and in some examples the carrier bandwidth may be referred to as a “system bandwidth” of the carrier or the wireless communications system  100 . For example, the carrier bandwidth may be one of a number of determined bandwidths for carriers of a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz)). Devices of the wireless communications system  100  (e.g., the base stations  105 , the UEs  115 , or both) may have hardware configurations that support communications over a particular carrier bandwidth or may be configurable to support communications over one of a set of carrier bandwidths. In some examples, the wireless communications system  100  may include base stations  105  or UEs  115  that support simultaneous communications via carriers associated with multiple carrier bandwidths. In some examples, each served UE  115  may be configured for operating over portions (e.g., a sub-band, a BWP) or all of a carrier bandwidth. 
     Signal waveforms transmitted over a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a resource element may consist of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both). Thus, the more resource elements that a UE  115  receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE  115 . A wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers or beams), and the use of multiple spatial layers may further increase the data rate or data integrity for communications with a UE  115 . 
     The time intervals for the base stations  105  or the UEs  115  may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of T s =1/(Δf max ·N f ) seconds, where Δf max  may represent the maximum supported subcarrier spacing, and N f  may represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of a communications resource may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023). 
     Each frame may include multiple consecutively numbered subframes or slots, and each subframe or slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a number of slots. Alternatively, each frame may include a variable number of slots, and the number of slots may depend on subcarrier spacing. Each slot may include a number of symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period). In some wireless communications systems  100 , a slot may further be divided into multiple mini-slots containing one or more symbols. Excluding the cyclic prefix, each symbol period may contain one or more (e.g., N f ) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or frequency band of operation. 
     A subframe, a slot, a mini-slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system  100  and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communications system  100  may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)). 
     Physical channels may be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET)) for a physical control channel may be defined by a number of symbol periods and may extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) may be configured for a set of the UEs  115 . For example, one or more of the UEs  115  may monitor or search control regions for control information according to one or more search space sets, and each search space set may include one or multiple control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to a number of control channel resources (e.g., control channel elements (CCEs)) associated with encoded information for a control information format having a given payload size. Search space sets may include common search space sets configured for sending control information to multiple UEs  115  and UE-specific search space sets for sending control information to a specific UE  115 . 
     In some examples, a base station  105  may be movable and therefore provide communication coverage for a moving geographic coverage area  110 . In some examples, different geographic coverage areas  110  associated with different technologies may overlap, but the different geographic coverage areas  110  may be supported by the same base station  105 . In other examples, the overlapping geographic coverage areas  110  associated with different technologies may be supported by different base stations  105 . The wireless communications system  100  may include, for example, a heterogeneous network in which different types of the base stations  105  provide coverage for various geographic coverage areas  110  using the same or different radio access technologies. 
     Some UEs  115  may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception simultaneously). In some examples, half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for the UEs  115  include entering a power saving deep sleep mode when not engaging in active communications, operating over a limited bandwidth (e.g., according to narrowband communications), or a combination of these techniques. For example, some UEs  115  may be configured for operation using a narrowband protocol type that is associated with a defined portion or range (e.g., set of subcarriers or resource blocks (RBs)) within a carrier, within a guard-band of a carrier, or outside of a carrier. 
     The wireless communications system  100  may be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof. For example, the wireless communications system  100  may be configured to support ultra-reliable low-latency communications (URLLC) or mission critical communications. The UEs  115  may be designed to support ultra-reliable, low-latency, or critical functions (e.g., mission critical functions). Ultra-reliable communications may include private communication or group communication and may be supported by one or more mission critical services such as mission critical push-to-talk (MCPTT), mission critical video (MCVideo), or mission critical data (MCData). Support for mission critical functions may include prioritization of services, and mission critical services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission critical, and ultra-reliable low-latency may be used interchangeably herein. 
     In some examples, a UE  115  may also be able to communicate directly with other UEs  115  over a device-to-device (D2D) communication link  135  (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs  115  utilizing D2D communications may be within the geographic coverage area  110  of a base station  105 . Other UEs  115  in such a group may be outside the geographic coverage area  110  of a base station  105  or be otherwise unable to receive transmissions from a base station  105 . In some examples, groups of the UEs  115  communicating via D2D communications may utilize a one-to-many (1:M) system in which each UE  115  transmits to every other UE  115  in the group. In some examples, a base station  105  facilitates the scheduling of resources for D2D communications. In other cases, D2D communications are carried out between the UEs  115  without the involvement of a base station  105 . 
     The core network  130  may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network  130  may be an evolved packet core (EPC) or 5G core (5GC), which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW), a Packet Data Network (PDN) gateway (P-GW), or a user plane function (UPF)). The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs  115  served by the base stations  105  associated with the core network  130 . User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions. The user plane entity may be connected to the network operators IP services  150 . The operators IP services  150  may include access to the Internet, Intranet(s), an IP Multimedia Subsystem (IMS), or a Packet-Switched Streaming Service. 
     Some of the network devices, such as a base station  105 , may include subcomponents such as an access network entity  140 , which may be an example of an access node controller (ANC). Each access network entity  140  may communicate with the UEs  115  through one or more other access network transmission entities  145 , which may be referred to as radio heads, smart radio heads, or transmission/reception points (TRPs). Each access network transmission entity  145  may include one or more antenna panels. In some configurations, various functions of each access network entity  140  or base station  105  may be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., a base station  105 ). 
     The wireless communications system  100  may operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length. The UHF waves may be blocked or redirected by buildings and environmental features, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs  115  located indoors. The transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz. 
     The wireless communications system  100  may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communications system  100  may employ License Assisted Access (LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in unlicensed radio frequency spectrum bands, devices such as the base stations  105  and the UEs  115  may employ carrier sensing for collision detection and avoidance. In some examples, operations in unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating in a licensed band (e.g., LAA). Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among other examples. 
     A base station  105  or a 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) communications, or beamforming. The antennas of a base station  105  or a UE  115  may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with a base station  105  may be located in diverse geographic locations. A base station  105  may have an antenna array with a number of rows and columns of antenna ports that the base station  105  may use to support beamforming of communications with a UE  115 . Likewise, a UE  115  may have one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, an antenna panel may support radio frequency beamforming for a signal transmitted via an antenna port. 
     Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station  105 , a UE  115 ) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that some signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying amplitude offsets, phase offsets, or both to signals carried via the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation). 
     The wireless communications system  100  may be a packet-based network that operates according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate over logical channels. A MAC layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use error detection techniques, error correction techniques, or both to support retransmissions at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE  115  and a base station  105  or a core network  130  supporting radio bearers for user plane data. At the physical layer, transport channels may be mapped to physical channels. 
     In some examples, the wireless communications system  100  may support multi-panel communications between a UE  115  and a base station  105 . As an illustrative example, the UE may use a first panel to communicate with a first TRP associated with the base station  105 , a second panel to communicate with a second TRP associated with the base station  105 , etc. In some examples, different panels of the UE  115  may be associated with different parameters (e.g., power parameters), conditions (e.g., one or more panels may experience an MPE event), etc. 
     In accordance with the techniques described herein, the wireless communications system  100  may implement multi-panel power headroom reports for communications between devices, which may enable the devices to accurately indicate power capabilities, more efficiently schedule communications, or enhance power management, among other benefits. For example, a UE  115  may communicate with a base station  105  using a first panel and a second panel (e.g., a first antenna panel and a second antenna panel). The UE  115  may determine one or more panel specific power headroom values to report to the base station  105 . For example, the UE  115  may calculate a first power headroom value for the first panel (e.g., based on one or more panel specific parameters, such as a maximum transmit power parameter associated with the first panel, a maximum power reduction parameter associated with the first panel, etc.). Additionally or alternatively, the UE  115  may calculate a second power headroom value for the second panel (e.g., using one or more panel specific parameters, such as a maximum transmit power parameter associated with the second panel, a maximum power reduction parameter associated with the second panel, etc.). 
     The UE  115  may transmit a power headroom report indicating the one or more panel specific power headroom values. In some examples, the UE  115  may transmit the power headroom report based on identifying that one or more thresholds associated with the power headroom report are satisfied. For example, the UE  115  may determine that a timer associated with the power headroom report has expired, that one or more power backoff metrics satisfy one or more thresholds (e.g., a change in a power backoff metric for the first panel, the second panel, or both may satisfy a change threshold), that a medium access control (MAC) entity has uplink resources for an uplink transmission, or any combination thereof. The power headroom report may include one or more fields indicating the panel specific power headroom values. For example, the UE  115  may populate one or more fields of the report, the one or more fields indicating whether the first power headroom value for the first panel is included in the report, whether the second power headroom value for the second panel is included in the report, whether a MAC entity applies power management techniques, whether a panel specific power headroom value is based on a real transmission format or a virtual transmission format, or any combination thereof, among other examples of fields. 
       FIG.  2    illustrates an example of a wireless communications system  200  that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. In some examples, the wireless communications system  200  may implement aspects of wireless communication system  100 . For example, the wireless communications system  200  may include UE  115 - a  and base station  105 - a , which may be examples of a UE  115  and a base station  105  as described with reference to  FIG.  1   . 
     The wireless communications system  200  may support multi-panel communications  205  between the UE  115 - a  and the base station  105 - a  in a geographic area  110 - a . As an illustrative example, the UE  115 - a  may send uplink transmissions using a first panel (e.g., a first set of antennas of the first panel) to the base station  105 - a , a second panel (e.g., a second set of antennas of the second panel) to the base station  105 - a , or both. 
     In some examples, the UE  115 - a  may implement power management techniques (e.g., power control for uplink transmissions, such as physical uplink shared channel transmissions using one or more panels). For example, the UE  115 - a  may transmit a report  210  to the base station  105 - a  indicating a power headroom of the UE  115 - a . For example, the UE  115 - a  may determine the power headroom as a difference between the maximum transmit power of the UE  115 - a  and a transmit power of the UE  115 - a  (e.g., a currently used transmit power, a predicted transmit power, among other examples). 
     In some examples, the UE  115 - a  may calculate the transmit power of the UE  115 - a . For example, the UE  115 - a  may calculate a real transmission power based on one or more configured values (e.g., configured by the base station  105 - a , pre-configured at the UE  115 - a , or a combination thereof), a resource assignment from the base station  105 - a , among other examples of factors for calculating a transmit power. As an illustrative example, the UE  115 - a  may calculate a real transmission power “P PUSCH (i,j,q d ,l)” using Equation 1: 
         P   PUSCH ( i,j,q   d   ,l )= P   O     PUSCH,b,f,c   ( j )+10 log 10 (2 μ   M   RB,b,f,c   PUSCH ( i ))+α b,f,c, ( j ) PL   b,f,c ( q   d )+Δ TF,b,f,c ( i )+ f   b,f,c ( i,l )  (1)
 
     In Equation 1, the P O     PUSCH,b,f,c   (j) may represent a target signal to noise ratio (SINR) (e.g., set by a P 0  value of a configuration of the UE  115 - a ), the M RB,b,f,c   PUSCH (i) may represent the bandwidth of a physical uplink shared channel (PUSCH) resource assignment (e.g., expressed in a number of resource blocks for a scheduled PUSCH transmission), the α b,f,c, (j) may represent a path loss compensation factor, the PL b,f,c (q d ) may represent a path loss reference (e.g., which may be referred to as “RS”), the Δ TF,b,f,c (i) may represent a modulation and coding scheme (MCS) related adjustment (e.g., the power may depend on an MCS scheme associated with PUSCH transmission), and the f b,f,c (i,l) may represent the a PUSCH power control adjustment state. In some examples, the various factors used to calculate the real transmission power may be configured at the UE  115 - a  (e.g., via RRC signaling, pre-configured values at the UE  115 - a , etc.), or the UE  115 - a  may otherwise determine the factors (e.g., based on control information from the base station  105 - a , or other methods of determination). For example, the parameters i, j, q d , l may be default parameters or may be signaled parameters, or a combination thereof. 
     In some examples, the UE  115 - a  may calculate a virtual transmission power based on one or more configured values (e.g., one or more default parameters configured to use as values for i, j, q d , l). As an illustrative example, the UE  115 - a  may calculate a virtual transmission power “P PUSCH (i, q d , l)” using Equation 2: 
         P   PUSCH ( i,j,q   d   ,l )= P   O     PUSCH,b,f,c   ( j )+α b,f,c, ( j ) PL   b,f,c ( q   d )+ f   b,f,c ( i,l )  (2)
 
     In some examples, the maximum transmit power (e.g., a configured UE maximum output power PCMAX f,c  for a carrier “f” of a serving cell “c”) may be set such that a corresponding measurement satisfies a threshold. For example, the maximum transmit power may be set such that a measured peak of an effective isotropically radiated power (EIRP) (e.g., which may be referred to as “PUMAX ,f,c ”) is within bounds illustrated by Equation 3: 
         EIRP max≥ PU MAX ,f,c   ≥P   Powerclass −MAX(MAX( MPR   f,c   ,A−MPR   f,c )+Δ MBP   n   ,P−MPR   f,c )−MAX{ T (MAX( MPR   f,c   ,A−MPR   f,c )), T ( P−MPR   f,c )}  (3)
 
     In some examples, the various factors used in Equation 3 may be configured at the UE  115 - a  (e.g., via RRC signaling, pre-configured values at the UE  115 - a , etc.), or the UE  115 - a  may otherwise determine the factors (e.g., based on control information from the base station  105 - a , or other methods of determination). The P-MPR f,c  may represent an allowed maximum output power reduction configured at the UE  115 - a . In some examples, the P-MPR f,c  may be referred to as power management maximum power reduction parameter. 
     In some examples, the UE  115 - a  may apply the maximum output power reduction for a carrier f of a serving cell c for one or more cases. For example, the UE  115 - a  may apply the maximum output power reduction to ensure compliance with applicable electromagnetic power density exposure thresholds, addressing unwanted emissions, self-defence requirements in the event of simultaneous transmissions on multiple radio access technologies, ensuring compliance with the applicable electromagnetic power density exposure thresholds in the case that proximity detection is used to address such thresholds that may result in a lower maximum output power, or any combination thereof. 
     In some examples, the UE  115 - a  may report one or more parameters (e.g., the available maximum output transmit power) to the base station  105 - a  in the report  210 . The base station  105 - a  may perform scheduling based on the report  210 . For example, the base station  105 - a  may allocate resources to the UE  115 - a  based on the report  210  (e.g., the base station  105 - a  may increase resources and an associated data rate if the report  210  includes a power headroom with a positive value indicating that the UE  115 - a  may use more power and transmit more data, the base station  105 - a  may reduce resources and an associated data rate if the report  210  includes a power headroom with a negative value indicating that the UE  115 - a  is using more than a threshold amount of power, etc.), among other examples of scheduling decisions. Additionally or alternatively, the base station  105 - e  may transmit a signal indicating a power adjustment for one or more of the panels based on the report. In some examples, the parameters (e.g., the P-MPR f,c  and a maxUplinkDutyCycle-FR2 parameters) may impact a maximum uplink performance for a selected uplink transmission path. 
     In some examples, the wireless communications system  200  may support multi-panel power headroom indications. For example, the report  210  may be an example of a multi-panel power headroom report (e.g., the report  210  may indicate a power headroom value for a first panel for a carrier f of a serving cell c, the report  210  may indicate a power headroom value for a second panel for a carrier f of a serving cell c, etc.). Such reports  210  may enable the devices of the memory system  200  to accurately indicate power capabilities, more efficiently schedule communications, or enhance power management, among other benefits. For example, the UE  115 - a  may communicate with a base station  105 - a  using a first panel and a second panel (e.g., a first antenna panel and a second antenna panel). The UE  115 - a  may determine one or more panel specific power headroom values to report to the base station  105 - a . For example, the UE  115 - a  may calculate a first power headroom value for the first panel (e.g., based on one or more panel specific parameters, such as a maximum transmit power parameter associated with the first panel, a maximum power reduction parameter associated with the first panel, etc.). Additionally or alternatively, the UE  115 - a  may calculate a second power headroom value for the second panel (e.g., using one or more panel specific parameters, such as a maximum transmit power parameter associated with the second panel, a maximum power reduction parameter associated with the second panel, etc.). 
     The UE  115 - a  may transmit a power headroom report  210  indicating the one or more panel specific power headroom values. In some examples, the UE  115 - a  may transmit the power headroom report  210  based on identifying that one or more thresholds associated with the power headroom report  210  are satisfied. For example, the UE  115 - a  may determine that a timer associated with the power headroom report  210  has expired, that one or more power backoff metrics satisfy one or more thresholds (e.g., a change in a power backoff metric for the first panel, the second panel, or both may satisfy a change threshold), that a MAC entity has uplink resources for an uplink transmission, or any combination thereof. The power headroom report  210  may include one or more fields indicating the panel specific power headroom values. For example, the UE  115 - a  may populate one or more fields of the report  210 , the one or more fields indicating whether the first power headroom value for the first panel is included in the report  210 , whether the second power headroom value for the second panel is included in the report  210 , whether a MAC entity applies power management techniques, whether a panel specific power headroom value is based on a real transmission format or a virtual transmission format, or any combination thereof, among other examples of fields of the report  210 . 
       FIG.  3    illustrates examples of resource schemes  300 ,  301 , and  302  that support multi-panel power reporting techniques in accordance with aspects of the present disclosure. In some examples, the various resource schemes in  FIG.  3    may implement aspects of wireless communication systems  100  or  200 . For example, the resource schemes  300 ,  301 , and  302  may illustrate examples of multi-panel communications between a UE  115  and a base station  105 , as described with reference to  FIGS.  1  and  2   . 
     For example, the various resource schemes may include first resources  305  and second resources  310 . The first resources  305  may be an example of uplink resources associated with a first panel (e.g., PUSCH resources for uplink transmission via the first panel). As an illustrative example, the first resources may correspond to a first set of parameters (e.g., indicated by downlink control information (DCI) associated with a resource assignment). The first set of parameters may include one or more of a first transmitted precoding matrix index (TPMI), a first sounding reference signal (SRS) resource indicator (SRI), a first uplink tag control information (TCI), or any combination thereof, among other examples of parameters associated with a panel. The second resources  310  may be an example of uplink resources associated with a second panel (e.g., PUSCH resources for uplink transmission from the second panel). The second resources  310  may correspond to a second set of parameters (e.g., indicated by DCI associated with a resource assignment). The second set of parameters may include one or more of a second TMPI, a second SRI, a second uplink TCI, or any combination thereof, among other examples of parameters associated with a panel. In some examples, the base station may indicate the first resources  305  and/or the second resources  310  via a resource assignment (e.g., a signal indicating uplink resources for communications via a panel). 
     The resource scheme  300  may illustrate an example of spatial divisional multiplexing (SDM) for communicating using multiple panels. As an illustrative example, a UE may transmit one or more uplink transmissions using the first panel and the second panel in accordance with SDM communications. The first resources  305  and the second resources  310  may utilize overlapping resources in time and frequency (e.g., the same time frequency resources) but transmit on different spatial beams (e.g., the first panel may use a first focused signal beam in a first spatial configuration and the second panel may use a different second focused signal beam in a second spatial configuration). 
     The resource scheme  301  may illustrate an example of FDM for communicating using multiple panels. As an illustrative example, a UE may transmit one or more uplink transmissions using the first panel and the second panel in accordance with FDM communications. The first resources  305  and the second resources  310  may utilize overlapping resources in time (e.g., the same time resources) but may transmit on different frequencies (e.g., the first resources  305  may be allocated to a first frequency of a time period and the second resources  310  may be allocated to a second frequency of the time period). 
     The resource scheme  302  may illustrate an example of TDM for communicating using multiple panels. As an illustrative example, a UE may transmit one or more uplink transmissions using the first panel and the second panel in accordance with TDM communications. The first resources  305  and the second resources  310  may utilize overlapping resources in frequency (e.g., the same frequency band resources) but may transmit at different times (e.g., the first resources  305  may be allocated to a first frequency of a first time period and the second resources  310  may be allocated to a second time period of the first frequency). 
     In accordance with the techniques described herein, the resource schemes  300 ,  301 , and/or  302  may implement multi-panel power headroom reports for communications between devices, which may enable the devices to accurately indicate power capabilities, more efficiently schedule communications, or enhance power management, among other benefits. For example, a UE  115  may communicate with a base station  105  using a first panel and a second panel (e.g., a first antenna panel and a second antenna panel) in accordance with SDM, FDM, TDM, or any combination thereof. The UE  115  may determine one or more panel specific power headroom values to report to the base station  105 . For example, the UE  115  may calculate a first power headroom value for the first panel (e.g., based on one or more panel specific parameters, such as a maximum transmit power parameter associated with the first panel, a maximum power reduction parameter associated with the first panel, etc.). Additionally or alternatively, the UE  115  may calculate a second power headroom value for the second panel (e.g., using one or more panel specific parameters, such as a maximum transmit power parameter associated with the second panel, a maximum power reduction parameter associated with the second panel, etc.). 
     The UE  115  may transmit a power headroom report indicating the one or more panel specific power headroom values. In some examples, the UE  115  may transmit the power headroom report based on identifying that one or more thresholds associated with the power headroom report are satisfied. For example, the UE  115  may determine that a timer associated with the power headroom report has expired, that one or more power backoff metrics satisfy one or more thresholds (e.g., a change in a power backoff metric for the first panel, the second panel, or both may satisfy a change threshold), that a medium access control (MAC) entity has uplink resources for an uplink transmission, or any combination thereof. The power headroom report may include one or more fields indicating the panel specific power headroom values. For example, the UE  115  may populate one or more fields of the report, the one or more fields indicating whether the first power headroom value for the first panel is included in the report, whether the second power headroom value for the second panel is included in the report, whether a MAC entity applies power management techniques, whether a panel specific power headroom value is based on a real transmission format or a virtual transmission format, or any combination thereof, among other examples of fields. 
       FIG.  4    illustrates examples of wireless communications systems  400 ,  401 , and  402  that support multi-panel power reporting techniques in accordance with aspects of the present disclosure. In some examples, the various example wireless communications systems of  FIG.  4    may implement aspects of wireless communications systems  100  and  200 . For example, the wireless communications systems  400 ,  401 , and  402  may include UEs  115  and base stations  105 , which may be examples of the corresponding devices as described with reference to  FIGS.  1  and  2   . 
     The wireless communications system  400  may illustrate an example of communications between a UE  115 - b  and a base station  105 - b  in a geographic area  110 - b . The UE  115 - b  and the base station  105 - b  may communicate using a beam  415 - a  (e.g., one or more beams  415 - a  associated with a panel of the UE  115 - b ). For example, the UE  115 - b  may send uplink transmissions  405 - a  using the beam  415 - a  and may receive downlink transmissions  410 - a  from the base station  105 - b  (e.g., using a reception beam of the first panel used to transmit uplink transmissions  405 - a ). 
     The wireless communications system  401  may illustrate an example of communications between a UE  115 - c  and a base station  105 - c  in a geographic area  110 - c . Generally, the wireless communications system  401  may illustrate an example of an MPE event. For example, a person  420 - a  (or other objects/conditions) may be in a proximity and/or orientation that satisfies a threshold. As an illustrative example, the person  420 - a  may be located such that the uplink transmission  405 - b , using a configured power, may exceed a threshold power exposure of the person  420 - a . In order to ensure that the MPE threshold for the person  420 - a  is satisfied, the UE  115 - c  may be configured to reduce a power of the uplink transmission  405 - b  (e.g., the UE  115 - c  may reduce a power of a first panel associated with a transmit beam  415 - b ). In some examples, the base station  105 - c  may continue to transmit downlink transmissions  410 - b  due to a distance between the base station  105 - c  and the person  420 - a , a frequency of the downlink transmissions  410 - b , or both satisfying the MPE threshold. However, such an MPE event may result in relatively inefficient or unreliable communications. 
     The wireless communications system  402  may illustrate an example of a method to maintain communications with the base station  105 - d  in an MPE event. For example, the UE  115 - d  may continue to receive downlink transmissions  410 - c  from the base station  105 - d  using the beam  415 - c . Additionally or alternatively, the UE  115 - d  may use a second panel to communicate uplink transmissions  405 - c  to the base station  105 - d . For example, the UE  115 - d  may include a second panel that is not experiencing an MPE event (e.g., transmission using the beam  415 - d  may satisfy a threshold power exposure of the person  420 - b , but uplink transmission using a beam  415 - c  may fail to satisfy the threshold and the UE  115 - d  may reduce a power of a first panel for uplink transmissions as described above). The UE  115 - d  may switch from communicating with the first panel to communicating with the second panel in response to the MPE event (e.g., the UE  115 - d  may switch from beam  415 - c  to beam  415 - d  to satisfy a power exposure threshold for uplink transmissions  405 - c ). In other words, downlink communications  410 - c  may be maintained and uplink transmissions  405 - c  may be altered. In some examples, the UE  115 - d  may receive downlink transmissions  410 - c  from a first TRP of the base station  150 - d  and communicate the uplink transmissions  405 - c  with a node  425  (e.g., a second TRP of the base station  150 - d ). Additionally or alternatively, the node may be an example of another base station  105 , among other examples of wireless nodes. In some other examples, the UE  115 - d  may send uplink transmissions  405 - c  to the first TRP of the base station  105 - d  using the second beam  415 - d.    
     However, in some examples, power reporting techniques may be relatively inefficient. For example, the UE  115 - d  may report a power headroom of the UE  115 - d  but may be unable to report multi-panel power headroom values. In such examples, the UE  115 - d  may be unable to accurately report power headroom values for different panels or the base station  105 - d  may be unaware of the MPE event, which may result in inefficient communications or relatively poor power management. For example, the base station  105 - d  may schedule uplink resources expecting a power of uplink transmissions  405  above a power threshold of the reduced power for the first panel (e.g., in response to the MPE event), the base station  105 - d  may fail to allocate resources to the second panel capable of using more power for uplink transmissions  405 - c  (e.g., resulting in inefficient communications), among other examples. 
     In accordance with the techniques described herein, the wireless communications systems  400 ,  401 , and/or  402  may implement multi-panel power headroom reports for communications between devices, which may enable the devices to accurately indicate power capabilities, more efficiently schedule communications, or enhance power management, among other benefits. For example, a UE  115  may communicate with a base station  105  using a first panel and a second panel (e.g., a first antenna panel and a second antenna panel) in accordance with SDM, FDM, TDM, or any combination thereof. The UE  115  may determine one or more panel specific power headroom values to report to the base station  105 . For example, the UE  115  may calculate a first power headroom value for the first panel (e.g., based on one or more panel specific parameters, such as a maximum transmit power parameter associated with the first panel, a maximum power reduction parameter associated with the first panel, etc.). Additionally or alternatively, the UE  115  may calculate a second power headroom value for the second panel (e.g., using one or more panel specific parameters, such as a maximum transmit power parameter associated with the second panel, a maximum power reduction parameter associated with the second panel, etc.). 
     The UE  115  may transmit a power headroom report indicating the one or more panel specific power headroom values. In some examples, the UE  115  may transmit the power headroom report based on identifying that one or more thresholds associated with the power headroom report are satisfied. For example, the UE  115  may determine that a timer associated with the power headroom report has expired, that one or more power backoff metrics satisfy one or more thresholds (e.g., a change in a power backoff metric for the first panel, the second panel, or both may satisfy a change threshold), that a medium access control (MAC) entity has uplink resources for an uplink transmission, or any combination thereof. The power headroom report may include one or more fields indicating the panel specific power headroom values. For example, the UE  115  may populate one or more fields of the report, the one or more fields indicating whether the first power headroom value for the first panel is included in the report, whether the second power headroom value for the second panel is included in the report, whether a MAC entity applies power management techniques, whether a panel specific power headroom value is based on a real transmission format or a virtual transmission format, or any combination thereof, among other examples of fields. 
       FIG.  5    illustrates an example of a process flow  500  that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. In some examples, the process flow  500  may implement aspects of wireless communications systems  100 ,  200 ,  400 ,  401 ,  402 , or any combination thereof. For example, the process flow  500  may illustrate operations performed by a UE  115 - e  or a base station  105 - e , which may be examples of the corresponding devices described herein. In some examples, the process flow  500  may illustrate implementation of a multi-panel power headroom report for multi-panel communications between the UE  115 - e  and the base station  105 - e.    
     In some examples, at  505 , the base station  105 - e  may transmit control signaling to the UE  115 - e . For example, the base station  105 - e  may send DCI indicating one or more resource assignments for communications with the UE  115 - e  (e.g., the DCI may indicate first resources for an uplink transmission from the UE  115 - e  using a first panel, second resources for an uplink transmissions from the UE  115 - e  using a second panel). 
     At  510 , the UE  115 - e  and the base station  105 - e  may communicate. In some examples, the UE  115 - e  and the base station  105 - e  may communicate using multi-panel communications as described herein, for example, with reference to  FIGS.  1 - 4   . As an illustrative example, the UE  115 - e  may send one or more uplink transmissions using one or more panels of the UE  115 - e  (e.g., a first panel and a second panel associated with communications over a carrier). 
     In some examples, at  515  the UE  115 - e  may determine that one or more threshold are satisfied (e.g., the UE  115 - e  may identify one or more triggers for transmitting a multi-panel power headroom report). For example, the UE  115 - e  may determine that a timer associated with the power headroom report has expired (e.g., the UE  115 - e  may determine that a timer phr-ProhibitTimer has expired and may transmit a report based on the expiration). 
     Additionally or alternatively, the UE  115 - e  may determine that one or more power backoff metrics satisfy one or more thresholds. As an illustrative example, a UE  115 - e  may include two panels (e.g., a first panel corresponding to a k value of 0 and a second panel corresponding to a k value of 1) and may communicate with the base station  105 - e  using the two panels at  510 . The UE  115 - e  may determine that a power headroom report has been triggered, for example, if a change in a power backoff metric associated with at least one of the first panel, the second panel, or both satisfies a threshold. For example, the UE  115 - e  may determine that either one of a power backoff associated with the first panel (e.g., a power management maximum power reduction parameter of the first panel, which may be referred to as P-MPR(1)) or a power backoff associated with the second panel (e.g., a power management maximum power reduction parameter of the second panel, which may be referred to as P-MPR(2)) satisfies a threshold. Additionally or alternatively, the UE  115 - e  may determine that both the power backoff associated with the first panel and the power backoff associated with the second panel satisfy the threshold. Additionally or alternatively, the UE  115 - e  may determine that a sum of the power backoffs of the first panel and the second panel satisfy the threshold. 
     As an illustrative example, the UE  115 - e  may report a multi-panel power headroom report based on the one or more satisfied thresholds. For example, the power headroom report may be triggered based on detecting an expiration of a timer (e.g., phr-ProhibitTimer has expired), that a MAC entity has uplink resources for a new transmission from the UE  115 - e , that there are uplink resources allocated for transmission or there is a physical uplink control channel (PUCCH) transmission on a serving cell associated with the first panel and the second panel, and a power backoff (e.g., due to power management, as discussed herein with reference to  FIG.  2   ) for the cell has change more than a threshold associated with the power headroom report (e.g., phr-Tx-PowerFactorChange dB) since a last transmission of a power headroom report when the MAC entity had uplink resources allocated for transmission or PUCCH transmission on the cell, or any combination thereof. 
     At  520 , the UE  115 - e  may determine one or more power headroom values, for example, based on determining that the one or more thresholds are satisfied. For example, the UE  115 - e  may support per panel power headroom calculation at the UE  115 - e  as described herein. The UE  115 - e  may calculate a first power headroom value for a first panel, a second power headroom value for a second panel, or both  9  e.g., among other examples of quantities of panels). As an illustrative example, the UE  115 - e  may calculate panel specific power headroom values for PUSCH transmissions using Equation 4: 
         PH   type1,b,f,c ( i,j,q   d   ,l,k )= P   CMAX,f,c ( i,k )− P   k,PUSCH ( i,j,q   d   ,l )  (4)
 
     In Equation 1, the PH type1,b,f,c (i,j,q d ,l,k) may represent a type 1 power headroom value for a PUSCH transmission for a panel k (e.g., a first panel may correspond to a panel index k of 0, a second panel may correspond to a panel index k of 1, and so on). The P CMAX,f,c (i,k) may represent a maximum transmit power for a panel k (e.g., configured at the UE  115 - e  as described herein). In some examples, the P CMAX,f,c (i,k) may be the same for multiple panels (e.g., configured as the same for each of the first and second panels). In some other examples, P CMAX,f,c (i,k) may be panel specific. For example, the P CMAX,f,c (i,k) may be based on a power management maximum power reduction parameter for a panel k (e.g., a panel specific P-MPR value represented by P-MPR(k)≥0 may be an example of a panel specific power reduction parameter used to calculate the P CMAX,f,c  (i,k)). In some examples, the P k,PUSCH (i,j,q d ,l) may represent a panel specific transmission power. 
     In some examples, the panel specific transmission power may be a real transmission power (e.g., the power headroom report value for a specific panel may be a real transmission power) or the panel specific transmission power may be a virtual transmission power (e.g., the power headroom report value for a specific panel may be a real transmission power). As an illustrative example, the UE  115 - e  may calculate the panel specific transmission power (e.g., for a panel k) as a real transmission power using Equation 5: 
         P   k,PUSCH ( i,j,q   d   ,l )= P   O     PUSCH     k,b,f,c ( j )+10 log 10 (2 μ   M   RB,k,b,f,c   PUSCH ( i ))+α k,b,f,c, ( j ) PL   k,b,f,c ( q   d )+Δ k,TF,b,f,c ( i )+ f   k,b,f,c ( i,l )  (5)
 
     In Equation 5, the P O     PUSCH     k,b,f,c (j) may represent a target signal to noise ratio (SINR) (e.g., set by a P 0  value of a configuration of the UE  115 - a ), the M RB,k,b,f,c   PUSCH (i) may represent the bandwidth of a PUSCH resource assignment (e.g., expressed in a number of resource blocks for a scheduled PUSCH transmission), the α k,b,f,c , (j) may represent a path loss compensation factor, the PL k,b,f,c (q d ) may represent a path loss reference (e.g., which may be referred to as “RS”), the Δ k,TF,b,f,c (i) may represent a MCS related adjustment (e.g., the power may depend on an MCS scheme associated with PUSCH transmission), and the f k,b,f,c (i,l) may represent the a PUSCH power control adjustment state. In some examples, the various factors used to calculate the real transmission power may be configured at the UE  115 - e  (e.g., via RRC signaling, pre-configured values at the UE  115 - e , etc.), or the UE  115 - e  may otherwise determine the factors (e.g., based on control information from the base station  105 - e , or other methods of determination). For example, the parameters i, j, q d , l may be default parameters or may be signaled parameters, or a combination thereof. In some examples, the various parameters in Equation 5 may be panel specific parameters (e.g., each panel k may correspond to an associated set of parameters used to calculate the transmission power), the parameters may be common for multiple panels, or any combination thereof. 
     In some examples, the UE  115 - e  may calculate a panel specific virtual transmission power based on one or more configured values (e.g., one or more default parameters configured to use as values for i, j, q d , l). As an illustrative example, the UE  115 - a  may calculate a virtual transmission power “P k,PUSCH (i,j,q d ,l)” for a panel k using Equation 6: 
         P   k,PUSCH ( i,j,q   d   ,l )= P   O     PUSCH     ,k,b,f,c ( j )+α k,b,f,c, ( j ) PL   k,b,f,c ( q   d )+ f   k,b,f,c ( i,l )  (6)
 
     At  525 , the UE  115 - e  may generate a report. For example, the UE  115 - e  may populate one or more fields of the report based at least in part on determining the power headroom values at  520 . The report may be an example of a multi-panel power headroom report as described herein. For example, the report may include at least one of a first power headroom value for a first panel of the UE  115 - e  or a second power headroom value for a second panel of the UE  115 - e . In some examples, the one or more fields may indicate whether the first power headroom value for the first panel is included in the report, whether the second power headroom value for the second panel is included in the report, whether a MAC entity applies power management techniques, whether a panel specific power headroom value is based on a real transmission format or a virtual transmission format, or any combination thereof, among other examples of fields. As an illustrative example, the UE  115 - e  may populate the report as shown below in Table 1. Table 1 may illustrate an example report format for the multi-panel power headroom report, for example, where each component carrier is associated with a report (e.g., including two power headroom values, among other examples of quantities of panel-specific power headroom values). 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 R 
                 P1 
                 P2 
                 Serving cell index 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 P 
                 V 
                 PH(type X, panel 0) 
                   
               
            
           
           
               
               
               
            
               
                 R 
                 P CMAX, f, c (0) 
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 P 
                 V 
                 PH(type X, panel 1) 
                   
               
            
           
           
               
               
               
            
               
                 R 
                 P CMAX, f, c (1) 
               
               
                   
               
            
           
         
       
     
     In Table 1, the P1 field may indicate whether a power headroom report (e.g., a power headroom value) is reported for the first panel. The P2 field may indicate whether a power headroom report (e.g., a power headroom value) is reported for the second panel. The P field may indicate whether the MAC entity applies power backoff due to power management (e.g., whether a P-MPR is implemented, a value of the P-MPR, or both). The V field may indicate if the power headroom value is based on a real transmission format or a virtual transmission reference format. In some examples, the V field may be set to 0 indicating a real transmission format and the presence of an octet including the associated P CMAX,f,c  field for a panel k, or the V field may be set to 1 indicating that a virtual transmission reference format and the octet including the associated P CMAX,f,c  field is omitted from the report. In some examples, the power headroom value field may indicate the power headroom value for a panel k, a type of the power headroom value (e.g., type 1, type 2, type 3, etc.), or any combination thereof. 
     At  530 , the UE  115 - e  may transmit the report to the base station  105 - e . In some examples, at  535  the base station  105 - e  may schedule resources based on the received report as described herein. For example, the base station  105 - e  may schedule subsequent communications with a first panel based on a power headroom value of the first panel indicated by the report, communications with a second panel based on a power headroom value of the second panel indicated by the report, or both, as described herein with reference to at least  FIGS.  1 - 4   . 
       FIG.  6    shows a block diagram  600  of a device  605  that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. The device  605  may be an example of aspects of a UE  115  as described herein. The device  605  may include a receiver  610 , a communications manager  615 , and a transmitter  620 . The device  605  may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). 
     The receiver  610  may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to multi-panel power reporting techniques, etc.). Information may be passed on to other components of the device  605 . The receiver  610  may be an example of aspects of the transceiver  920  described with reference to  FIG.  9   . The receiver  610  may utilize a single antenna or a set of antennas. 
     The communications manager  615  may communicate via a first panel of the UE and a second panel of the UE, determine at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel, and transmit, to a base station, a report indicating at least one of the first power headroom value for the first panel or the second power headroom value for the second panel. The communications manager  615  may be an example of aspects of the communications manager  910  described herein. 
     The communications manager  615 , or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager  615 , or its sub-components may be executed by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. 
     The communications manager  615 , or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager  615 , or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager  615 , or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure. 
     The actions performed by the communications manager  615  as described herein may be implemented to realize one or more potential advantages. One implementation may enable a UE  115  to transmit a multi-panel power headroom report. For example, the techniques may enable the UE  115  to calculate panel specific parameters and generate a report indicating one or more of the parameters as described herein. Such a report may enable the UE  115  to indicate panel specific power management events (e.g., MPE events) to a base station, which may enable more efficiency scheduling and communications in the system. 
     Based on implementing the techniques described herein, a processor of the UE  115  (e.g., a processor controlling the receiver  610 , the communications manager  615 , the transmitter  620 , or a combination thereof) may report a power headroom for different panels, which may save power at the UE  115  (e.g., the UE may realize reduced power usage at a panel based on the report), among other advantages. 
     The transmitter  620  may transmit signals generated by other components of the device  605 . In some examples, the transmitter  620  may be collocated with a receiver  610  in a transceiver module. For example, the transmitter  620  may be an example of aspects of the transceiver  920  described with reference to  FIG.  9   . The transmitter  620  may utilize a single antenna or a set of antennas. 
       FIG.  7    shows a block diagram  700  of a device  705  that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. The device  705  may be an example of aspects of a device  605 , or a UE  115  as described herein. The device  705  may include a receiver  710 , a communications manager  715 , and a transmitter  735 . The device  705  may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). 
     The receiver  710  may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to multi-panel power reporting techniques, etc.). Information may be passed on to other components of the device  705 . The receiver  710  may be an example of aspects of the transceiver  920  described with reference to  FIG.  9   . The receiver  710  may utilize a single antenna or a set of antennas. 
     The communications manager  715  may be an example of aspects of the communications manager  615  as described herein. The communications manager  715  may include a panel component  720 , a PHR component  725 , and a report component  730 . The communications manager  715  may be an example of aspects of the communications manager  910  described herein. 
     The panel component  720  may communicate via a first panel of the UE and a second panel of the UE. 
     The PHR component  725  may determine at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel. 
     The report component  730  may transmit, to a base station, a report indicating at least one of the first power headroom value for the first panel or the second power headroom value for the second panel. 
     The transmitter  735  may transmit signals generated by other components of the device  705 . In some examples, the transmitter  735  may be collocated with a receiver  710  in a transceiver module. For example, the transmitter  735  may be an example of aspects of the transceiver  920  described with reference to  FIG.  9   . The transmitter  735  may utilize a single antenna or a set of antennas. 
       FIG.  8    shows a block diagram  800  of a communications manager  805  that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. The communications manager  805  may be an example of aspects of a communications manager  615 , a communications manager  715 , or a communications manager  910  described herein. The communications manager  805  may include a panel component  810 , a PHR component  815 , a report component  820 , a population component  825 , a metric component  830 , a threshold component  835 , a comparison component  840 , a timer component  845 , a signal reception component  850 , a power parameter component  855 , and a calculation component  860 . Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses). 
     The panel component  810  may communicate via a first panel of the UE and a second panel of the UE. 
     The PHR component  815  may determine at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel. 
     The report component  820  may transmit, to a base station, a report indicating at least one of the first power headroom value for the first panel or the second power headroom value for the second panel. 
     The population component  825  may populate one or more fields of the report prior to transmission of the report, the one or more fields including a first field indicating whether the first power headroom value for the first panel is included in the report, and a second field indicating whether the second power headroom value for the second panel is included in the report. In some examples, the population component  825  may populate the report with at least one of the first power headroom value for the first panel or the second power headroom value for the second panel, where the report includes a first field for the first power headroom value and a second field for the second power headroom value. 
     The metric component  830  may identify one or more power backoff metrics including a first power backoff metric associated with the first panel, a second power backoff metric associated with the second panel, or both. 
     The threshold component  835  may determine that one or more thresholds are satisfied based on the identified one or more power backoff metrics, where transmitting the report is based on the satisfied one or more thresholds. 
     The comparison component  840  may compare a change of the one or more power backoff metrics to a change threshold of the one or more thresholds, where determining that the one or more thresholds are satisfied is based on the comparison. In some cases, the change of the one or more power backoff metrics includes a change of the first power backoff metric, a change of the second power backoff metric, a change of a sum of the first power backoff metric and the second power backoff metric, or any combination thereof. 
     The timer component  845  may determine an expiration of a timer associated with the report, where determining that the one or more thresholds are satisfied is based on the expiration of the timer. 
     The signal reception component  850  may receive a signal indicating uplink resources for a transmission from the UE, where determining that the one or more thresholds are satisfied is based on the received signal. In some examples, the signal reception component  850  may receive a signal indicating uplink resources for a transmission from the UE, where calculating the real transmission power is based on the indicated uplink resources. 
     The power parameter component  855  may identify a first maximum power parameter associated with the first panel based on a first power reduction parameter. In some examples, the power parameter component  855  may identify a second maximum power parameter associated with the second panel based on a second power reduction parameter different than the first power reduction parameter, where the first power reduction parameter corresponds to the first panel and the second power reduction parameter corresponds to the second panel. 
     The calculation component  860  may calculate the first power headroom value based on the first maximum power parameter. In some examples, the calculation component  860  may calculate the second power headroom value based on the first maximum power parameter, where the first maximum power parameter corresponds to both the first panel and the second panel. In some examples, the calculation component  860  may calculate the second power headroom value based on the second maximum power parameter. In some examples, the calculation component  860  may calculate a real transmission power or a virtual transmission power based on communicating via the first panel of the UE and the second panel of the UE, where determining at least one of the first power headroom value for the first panel or the second power headroom value for the second panel is based on the real transmission power or the virtual transmission power. 
       FIG.  9    shows a diagram of a system  900  including a device  905  that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. The device  905  may be an example of or include the components of device  605 , device  705 , or a UE  115  as described herein. The device  905  may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager  910 , an I/O controller  915 , a transceiver  920 , an antenna  925 , memory  930 , and a processor  940 . These components may be in electronic communication via one or more buses (e.g., bus  945 ). 
     The communications manager  910  may communicate via a first panel of the UE and a second panel of the UE, determine at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel, and transmit, to a base station, a report indicating at least one of the first power headroom value for the first panel or the second power headroom value for the second panel. 
     The I/O controller  915  may manage input and output signals for the device  905 . The I/O controller  915  may also manage peripherals not integrated into the device  905 . In some cases, the I/O controller  915  may represent a physical connection or port to an external peripheral. In some cases, the I/O controller  915  may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. In other cases, the I/O controller  915  may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller  915  may be implemented as part of a processor. In some cases, a user may interact with the device  905  via the I/O controller  915  or via hardware components controlled by the I/O controller  915 . 
     The transceiver  920  may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver  920  may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver  920  may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas. 
     In some cases, the wireless device may include a single antenna  925 . However, in some cases the device may have more than one antenna  925 , which may be capable of concurrently transmitting or receiving multiple wireless transmissions. 
     The memory  930  may include random-access memory (RAM) and read-only memory (ROM). The memory  930  may store computer-readable, computer-executable code  935  including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory  930  may contain, among other things, a basic input/output system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices. 
     The processor  940  may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor  940  may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor  940 . The processor  940  may be configured to execute computer-readable instructions stored in a memory (e.g., the memory  930 ) to cause the device  905  to perform various functions (e.g., functions or tasks supporting multi-panel power reporting techniques). 
     The code  935  may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code  935  may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code  935  may not be directly executable by the processor  940  but may cause a computer (e.g., when compiled and executed) to perform functions described herein. 
       FIG.  10    shows a block diagram  1000  of a device  1005  that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. The device  1005  may be an example of aspects of a base station  105  as described herein. The device  1005  may include a receiver  1010 , a communications manager  1015 , and a transmitter  1020 . The device  1005  may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). 
     The receiver  1010  may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to multi-panel power reporting techniques, etc.). Information may be passed on to other components of the device  1005 . The receiver  1010  may be an example of aspects of the transceiver  1320  described with reference to  FIG.  13   . The receiver  1010  may utilize a single antenna or a set of antennas. 
     The communications manager  1015  may communicate with a first panel of a UE and a second panel of the UE and receive, from the UE, a report indicating at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel. The communications manager  1015  may be an example of aspects of the communications manager  1310  described herein. 
     The communications manager  1015 , or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager  1015 , or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC), a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. 
     The communications manager  1015 , or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager  1015 , or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager  1015 , or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure. 
     The transmitter  1020  may transmit signals generated by other components of the device  1005 . In some examples, the transmitter  1020  may be collocated with a receiver  1010  in a transceiver module. For example, the transmitter  1020  may be an example of aspects of the transceiver  1320  described with reference to  FIG.  13   . The transmitter  1020  may utilize a single antenna or a set of antennas. 
       FIG.  11    shows a block diagram  1100  of a device  1105  that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. The device  1105  may be an example of aspects of a device  1005 , or a base station  105  as described herein. The device  1105  may include a receiver  1110 , a communications manager  1115 , and a transmitter  1130 . The device  1105  may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). 
     The receiver  1110  may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to multi-panel power reporting techniques, etc.). Information may be passed on to other components of the device  1105 . The receiver  1110  may be an example of aspects of the transceiver  1320  described with reference to  FIG.  13   . The receiver  1110  may utilize a single antenna or a set of antennas. 
     The communications manager  1115  may be an example of aspects of the communications manager  1015  as described herein. The communications manager  1115  may include a communication component  1120  and a report receiver  1125 . The communications manager  1115  may be an example of aspects of the communications manager  1310  described herein. 
     The communication component  1120  may communicate with a first panel of a UE and a second panel of the UE. 
     The report receiver  1125  may receive, from the UE, a report indicating at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel. 
     The transmitter  1130  may transmit signals generated by other components of the device  1105 . In some examples, the transmitter  1130  may be collocated with a receiver  1110  in a transceiver module. For example, the transmitter  1130  may be an example of aspects of the transceiver  1320  described with reference to  FIG.  13   . The transmitter  1130  may utilize a single antenna or a set of antennas. 
       FIG.  12    shows a block diagram  1200  of a communications manager  1205  that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. The communications manager  1205  may be an example of aspects of a communications manager  1015 , a communications manager  1115 , or a communications manager  1310  described herein. The communications manager  1205  may include a communication component  1210 , a report receiver  1215 , a signal transmitter  1220 , a report threshold component  1225 , a monitoring component  1230 , and a resources component  1235 . Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses). 
     The communication component  1210  may communicate with a first panel of a UE and a second panel of the UE. 
     The report receiver  1215  may receive, from the UE, a report indicating at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel. In some cases, the report includes one or more fields associated with a component carrier, the one or more fields including a first field indicating whether the first power headroom value for the first panel is included in the report, and a second field indicating whether the second power headroom value for the second panel is included in the report. In some cases, the report includes a first field for the first power headroom value and a second field for the second power headroom value. 
     The signal transmitter  1220  may transmit, to the UE, a signal indicating a power adjustment for at least one of the first panel or the second panel in response to receiving the report. In some examples, the signal transmitter  1220  may transmit a signal indicating the uplink resources. 
     The report threshold component  1225  may identify that one or more thresholds associated with the report are satisfied, the one or more thresholds including an expiration of a timer associated with the report. 
     The monitoring component  1230  may monitor for the report based on the one or more thresholds being satisfied. 
     The resources component  1235  may identify uplink resources for a transmission from the UE to the base station. 
       FIG.  13    shows a diagram of a system  1300  including a device  1305  that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. The device  1305  may be an example of or include the components of device  1005 , device  1105 , or a base station  105  as described herein. The device  1305  may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager  1310 , a network communications manager  1315 , a transceiver  1320 , an antenna  1325 , memory  1330 , a processor  1340 , and an inter-station communications manager  1345 . These components may be in electronic communication via one or more buses (e.g., bus  1350 ). 
     The communications manager  1310  may communicate with a first panel of a UE and a second panel of the UE and receive, from the UE, a report indicating at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel. 
     The network communications manager  1315  may manage communications with the core network (e.g., via one or more wired backhaul links). For example, the network communications manager  1315  may manage the transfer of data communications for client devices, such as one or more UEs  115 . 
     The transceiver  1320  may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver  1320  may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver  1320  may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas. 
     In some cases, the wireless device may include a single antenna  1325 . However, in some cases the device may have more than one antenna  1325 , which may be capable of concurrently transmitting or receiving multiple wireless transmissions. 
     The memory  1330  may include RAM, ROM, or a combination thereof. The memory  1330  may store computer-readable code  1335  including instructions that, when executed by a processor (e.g., the processor  1340 ) cause the device to perform various functions described herein. In some cases, the memory  1330  may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices. 
     The processor  1340  may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor  1340  may be configured to operate a memory array using a memory controller. In some cases, a memory controller may be integrated into processor  1340 . The processor  1340  may be configured to execute computer-readable instructions stored in a memory (e.g., the memory  1330 ) to cause the device  1305  to perform various functions (e.g., functions or tasks supporting multi-panel power reporting techniques). 
     The inter-station communications manager  1345  may manage communications with other base station  105 , and may include a controller or scheduler for controlling communications with UEs  115  in cooperation with other base stations  105 . For example, the inter-station communications manager  1345  may coordinate scheduling for transmissions to UEs  115  for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communications manager  1345  may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations  105 . 
     The code  1335  may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code  1335  may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code  1335  may not be directly executable by the processor  1340  but may cause a computer (e.g., when compiled and executed) to perform functions described herein. 
       FIG.  14    shows a flowchart illustrating a method  1400  that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. The operations of method  1400  may be implemented by a UE  115  or its components as described herein. For example, the operations of method  1400  may be performed by a communications manager as described with reference to  FIGS.  6  through  9   . In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware. 
     At  1405 , the UE may communicate via a first panel of the UE and a second panel of the UE. The operations of  1405  may be performed according to the methods described herein. In some examples, aspects of the operations of  1405  may be performed by a panel component as described with reference to  FIGS.  6  through  9   . 
     At  1410 , the UE may determine at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel. The operations of  1410  may be performed according to the methods described herein. In some examples, aspects of the operations of  1410  may be performed by a PHR component as described with reference to  FIGS.  6  through  9   . 
     At  1415 , the UE may transmit, to a base station, a report indicating at least one of the first power headroom value for the first panel or the second power headroom value for the second panel. The operations of  1415  may be performed according to the methods described herein. In some examples, aspects of the operations of  1415  may be performed by a report component as described with reference to  FIGS.  6  through  9   . 
       FIG.  15    shows a flowchart illustrating a method  1500  that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. The operations of method  1500  may be implemented by a UE  115  or its components as described herein. For example, the operations of method  1500  may be performed by a communications manager as described with reference to  FIGS.  6  through  9   . In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware. 
     At  1505 , the UE may communicate via a first panel of the UE and a second panel of the UE. The operations of  1505  may be performed according to the methods described herein. In some examples, aspects of the operations of  1505  may be performed by a panel component as described with reference to  FIGS.  6  through  9   . 
     At  1510 , the UE may determine at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel. The operations of  1510  may be performed according to the methods described herein. In some examples, aspects of the operations of  1510  may be performed by a PHR component as described with reference to  FIGS.  6  through  9   . 
     At  1515 , the UE may identify one or more power backoff metrics including a first power backoff metric associated with the first panel, a second power backoff metric associated with the second panel, or both. The operations of  1515  may be performed according to the methods described herein. In some examples, aspects of the operations of  1515  may be performed by a metric component as described with reference to  FIGS.  6  through  9   . 
     At  1520 , the UE may determine that one or more thresholds are satisfied based on the identified one or more power backoff metrics, where transmitting the report is based on the satisfied one or more thresholds. The operations of  1520  may be performed according to the methods described herein. In some examples, aspects of the operations of  1520  may be performed by a threshold component as described with reference to  FIGS.  6  through  9   . 
     At  1525 , the UE may transmit, to a base station, a report indicating at least one of the first power headroom value for the first panel or the second power headroom value for the second panel. The operations of  1525  may be performed according to the methods described herein. In some examples, aspects of the operations of  1525  may be performed by a report component as described with reference to  FIGS.  6  through  9   . 
       FIG.  16    shows a flowchart illustrating a method  1600  that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. The operations of method  1600  may be implemented by a base station  105  or its components as described herein. For example, the operations of method  1600  may be performed by a communications manager as described with reference to  FIGS.  10  through  13   . In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware. 
     At  1605 , the base station may communicate with a first panel of a UE and a second panel of the UE. The operations of  1605  may be performed according to the methods described herein. In some examples, aspects of the operations of  1605  may be performed by a communication component as described with reference to  FIGS.  10  through  13   . 
     At  1610 , the base station may receive, from the UE, a report indicating at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel. The operations of  1610  may be performed according to the methods described herein. In some examples, aspects of the operations of  1610  may be performed by a report receiver as described with reference to  FIGS.  10  through  13   . 
       FIG.  17    shows a flowchart illustrating a method  1700  that supports multi-panel power reporting techniques in accordance with aspects of the present disclosure. The operations of method  1700  may be implemented by a base station  105  or its components as described herein. For example, the operations of method  1700  may be performed by a communications manager as described with reference to  FIGS.  10  through  13   . In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware. 
     At  1705 , the base station may communicate with a first panel of a UE and a second panel of the UE. The operations of  1705  may be performed according to the methods described herein. In some examples, aspects of the operations of  1705  may be performed by a communication component as described with reference to  FIGS.  10  through  13   . 
     At  1710 , the base station may receive, from the UE, a report indicating at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel. The operations of  1710  may be performed according to the methods described herein. In some examples, aspects of the operations of  1710  may be performed by a report receiver as described with reference to  FIGS.  10  through  13   . 
     At  1715 , the base station may transmit, to the UE, a signal indicating a power adjustment for at least one of the first panel or the second panel in response to receiving the report. The operations of  1715  may be performed according to the methods described herein. In some examples, aspects of the operations of  1715  may be performed by a signal transmitter as described with reference to  FIGS.  10  through  13   . 
     It should be noted that the methods described herein describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined. 
     Example 1: A method of wireless communications at a UE, comprising: communicating via a first panel of the UE and a second panel of the UE, determining at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel, and transmitting, to a base station, a report indicating at least one of the first power headroom value for the first panel or the second power headroom value for the second panel. 
     Example 2: The method of example 1, further comprising: populating one or more fields of the report prior to transmission of the report, the one or more fields including a first field indicating whether the first power headroom value for the first panel is included in the report, and a second field indicating whether the second power headroom value for the second panel is included in the report. 
     Example 3: The method of examples 1 or 2, further comprising: populating the report with at least one of the first power headroom value for the first panel or the second power headroom value for the second panel, wherein the report includes a first field for the first power headroom value and a second field for the second power headroom value. 
     Example 4: The method of any of examples 1 to 3, further comprising: identifying one or more power backoff metrics comprising a first power backoff metric associated with the first panel, a second power backoff metric associated with the second panel, or both; and determining that one or more thresholds are satisfied based at least in part on the identified one or more power backoff metrics, wherein transmitting the report is based at least in part on the satisfied one or more thresholds. 
     Example 5: The method of any of examples 1 to 4, further comprising: comparing a change of the one or more power backoff metrics to a change threshold of the one or more thresholds, wherein determining that the one or more thresholds are satisfied is based at least in part on the comparison. 
     Example 6: The method of any of examples 1 to 5, wherein the change of the one or more power backoff metrics comprises a change of the first power backoff metric, a change of the second power backoff metric, a change of a sum of the first power backoff metric and the second power backoff metric, or any combination thereof. 
     Example 7: The method of any of examples 1 to 6, further comprising: determining an expiration of a timer associated with the report, wherein determining that the one or more thresholds are satisfied is based at least in part on the expiration of the timer. 
     Example 8: The method of any of examples 1 to 7, further comprising: receiving a signal indicating uplink resources for a transmission from the UE, wherein determining that the one or more thresholds are satisfied is based at least in part on the received signal. 
     Example 9: The method of any of examples 1 to 8, wherein determining at least one of the first power headroom value or the second power headroom value comprises: identifying a first maximum power parameter associated with the first panel based at least in part on a first power reduction parameter; and calculating the first power headroom value based at least in part on the first maximum power parameter. 
     Example 10: The method of any of examples 1 to 9, further comprising: calculating the second power headroom value based at least in part on the first maximum power parameter, wherein the first maximum power parameter corresponds to both the first panel and the second panel. 
     Example 11: The method of any of examples 1 to 10, further comprising: identifying a second maximum power parameter associated with the second panel based at least in part on a second power reduction parameter different than the first power reduction parameter, wherein the first power reduction parameter corresponds to the first panel and the second power reduction parameter corresponds to the second panel; and calculating the second power headroom value based at least in part on the second maximum power parameter. 
     Example 12: The method of any of examples 1 to 11, further comprising: calculating a real transmission power or a virtual transmission power based at least in part on communicating via the first panel of the UE and the second panel of the UE, wherein determining at least one of the first power headroom value for the first panel or the second power headroom value for the second panel is based at least in part on the real transmission power or the virtual transmission power. 
     Example 13: The method of any of examples 1 to 12, further comprising: receiving a signal indicating uplink resources for a transmission from the UE, wherein calculating the real transmission power is based at least in part on the indicated uplink resources. 
     Example 14: An apparatus comprising at least one means for performing a method of any of examples 1 to 13. 
     Example 15: An apparatus for wireless communications comprising a processor; memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of examples 1 to 13. 
     Example 16: A non-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by a processor to perform a method of any of embodiments 1 to 13. 
     Example 17: A method of wireless communications at a base station, comprising: communicating with a first panel of a user equipment (UE) and a second panel of the UE; and receiving, from the UE, a report indicating at least one of a first power headroom value for the first panel or a second power headroom value for the second panel, the first power headroom value being specific to the first panel and the second power headroom value being specific to the second panel. 
     Example 18: The method of example 17, further comprising: transmitting, to the UE, a signal indicating a power adjustment for at least one of the first panel or the second panel in response to receiving the report. 
     Example 19: The method of examples 17 or 18, wherein the report includes one or more fields associated with a component carrier, the one or more fields including a first field indicating whether the first power headroom value for the first panel is included in the report, and a second field indicating whether the second power headroom value for the second panel is included in the report. 
     Example 20: The method of any of examples 17 to 19, wherein the report includes a first field for the first power headroom value and a second field for the second power headroom value. 
     Example 21: The method of any of examples 17 to 20, further comprising: identifying that one or more thresholds associated with the report are satisfied, the one or more thresholds comprising an expiration of a timer associated with the report; and monitoring for the report based at least in part on the one or more thresholds being satisfied. 
     Example 22: The method of any of examples 17 to 21, further comprising: identifying uplink resources for a transmission from the UE to the base station; and transmitting a signal indicating the uplink resources. 
     Example 23: An apparatus comprising at least one means for performing a method of any of examples 17 to 22. 
     Example 24: An apparatus for wireless communications comprising a processor; memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of examples 17 to 22. 
     Example 25: A non-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by a processor to perform a method of any of embodiments 17 to 22. 
     Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to various other wireless communications systems such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, as well as other systems and radio technologies not explicitly mentioned herein. 
     Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. 
     The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may 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). 
     The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. 
     Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media. 
     As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of”) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on.” 
     In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label. 
     The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration,” and not “preferred” or “advantageous over other examples.” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples. 
     The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.