Power headroom reporting procedure for multiple cells

Abstract

Methods, systems, and devices for wireless communications are described. In some wireless communication systems, a device (such as a user equipment) may report power headroom measurements. To support accurate and reliable power headroom reporting (PHR), a UE may receive a first downlink control information (DCI) transmission for a first cell and determine whether a second DCI transmission for a second cell is received. The UE may generate a PHR based on whether a second DCI transmission is received after the first DCI transmission, and may transmit a PHR including power headroom values ​​for both cells. The UE may determine whether to perform actual or virtual power headroom calculations for the second cell based on when the second DCI is received. Additionally or alternatively, the UE may determine whether to discard resources scheduled by the first or second DCI, and may transmit a PHR in the remaining resources.

Description

[0001] Cross-references

[0002] This patent application claims priority to U.S. patent application No. 16 / 731,017, entitled “POWER HEADROOM REPORTING PROCEDURE FOR MULTIPLE CELLS,” filed by HOSSEINI et al. on December 30, 2019, and U.S. provisional patent application No. 62 / 787,627, entitled “POWER HEADROOM REPORTING PROCEDURE FOR MULTIPLE CELLS,” filed by HOSSEINI et al. on January 2, 2019, each of which is assigned to the assignee of this application.

[0003] background

[0004] The following relates generally to wireless communications, and more particularly to power headroom reporting procedures for multiple cells.

[0005] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcasting, etc. These systems may be able to support communication with multiple users by sharing 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, advanced LTE (LTE-A) systems, or LTE-A Pro systems), and fifth generation (5G) systems that may be referred to as new radio (NR) systems. These systems may use various 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 communication system may include several base stations or network access nodes, each of which simultaneously supports the communication of multiple communication devices, which may be referred to as user equipment (UE).

[0006] Overview

[0007] The described techniques relate to improved methods, systems, devices, and apparatuses that support power headroom reporting procedures for multiple cells. In general, the described techniques enable a user equipment (UE) to accurately and reliably report power headroom measurements for multiple cells in at least one power headroom report (PHR). In some wireless communication systems, the UE may report power headroom measurements to a base station based on one or more triggers or conditions (e.g., a periodic timer, a prohibition timer, or some combination of these or other configured timers or triggers). As an example, the UE may receive a first downlink control information (DCI) transmission for a first cell and may determine whether a second DCI transmission for a second cell is received after the first DCI. The UE may generate a PHR including power headroom measurements for multiple cells (e.g., first and second cells) based on whether the second DCI transmission is received and may transmit the PHR in uplink resources.

[0008] In some cases, the UE may determine whether to perform actual or virtual power headroom calculations for the second cell based on when the second DCI is received. For example, if the UE receives the second DCI after the first DCI but before the PHR reference time based on the UE processing capability and the uplink resources for power headroom reporting, the UE may perform a relatively accurate power headroom calculation for the second cell based on the received second DCI (e.g., due to sufficient processing time). Additionally or alternatively, if the two resource sets of the first resources scheduled by the first DCI and the second resources scheduled by the second DCI overlap partially or completely in time, the UE may determine whether to discard the first resources scheduled by the first DCI or the second resources scheduled by the second DCI, and the UE may transmit PHRs for the two cells in the resources that are not discarded. This may improve the reliability of transmitting PHRs in situations where resource allocations overlap.

[0009] A method for wireless communication by a UE is described. The method may include: identifying a trigger for transmitting a PHR; receiving a first DCI for a first cell indicating a first uplink resource; determining whether a second DCI for a second cell indicating a second uplink resource is received after receiving the first DCI and before the first uplink resource; and transmitting a PHR including a first power headroom for the first cell and a second power headroom for the second cell, wherein the PHR is based on the determination.

[0010] An apparatus for wireless communication by a UE is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to: identify a trigger for transmitting a PHR; receive a first DCI indicating a first uplink resource for a first cell; determine whether a second DCI indicating a second uplink resource for a second cell is received after receiving the first DCI and before the first uplink resource; and transmit a PHR including a first power headroom for the first cell and a second power headroom for the second cell, wherein the PHR is based on the determination.

[0011] Another apparatus for wireless communications by a UE is described. The apparatus may include means for: identifying a trigger for transmitting a PHR; receiving a first DCI for a first cell indicating a first uplink resource; determining whether a second DCI for a second cell indicating a second uplink resource is received after receiving the first DCI and before the first uplink resource; and transmitting a PHR including a first power headroom for the first cell and a second power headroom for the second cell, wherein the PHR is based on the determination.

[0012] A non-transitory computer-readable medium storing code for wireless communication by a UE is described. The code may include instructions executable by a processor for the following operations: identifying a trigger for transmitting a PHR; receiving a first DCI indicating a first uplink resource for a first cell; determining whether a second DCI indicating a second uplink resource for a second cell is received after receiving the first DCI and before the first uplink resource; and transmitting a PHR including a first power headroom for the first cell and a second power headroom for the second cell, wherein the PHR is based on the determination.

[0013] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for calculating a first power headroom based on a transmit power indicated by a first DCI, wherein the PHR is based on calculating the first power headroom.

[0014] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for determining whether a second DCI can be received before a PHR reference time based on a power headroom processing timeline for a first cellular cell and an initial symbol of a first uplink resource, and calculating a second power headroom based on determining whether the second DCI can be received before the PHR reference time, wherein the PHR is based on calculating the second power headroom.

[0015] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for the following actions: receiving a second DCI after receiving the first DCI and before the PHR reference time, and calculating a second power headroom based on the transmit power indicated by the second DCI, wherein the PHR is based on calculating the second power headroom.

[0016] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for determining that a second DCI is not received after the first DCI and before the PHR reference time, wherein calculating the second power headroom may be based on determining that the second DCI is not received.

[0017] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for calculating a second power headroom using a virtual calculation, the virtual calculation may be based on one or more preconfigured parameters, one or more parameters indicated by the first DCI, or a combination thereof, wherein the PHR may be based on calculating the second power headroom.

[0018] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for calculating a second power headroom based on a transmit power of a previous uplink resource for a second cell, wherein the previous uplink resource was scheduled prior to receiving the first DCI, wherein the PHR may be based on calculating the second power headroom.

[0019] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, apparatuses, or instructions for the following actions: calculating a second power headroom based on a transmit power of a previous non-granted uplink opportunity or a next non-granted uplink opportunity for a second cellular cell, wherein the previous non-granted uplink opportunity was scheduled before receiving the first DCI, and the next non-granted uplink opportunity is scheduled after receiving the first DCI, wherein the PHR can be based on calculating the second power headroom.

[0020] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for the following actions: receiving a second DCI after a PHR reference time, wherein determining that the second DCI is not received after the first DCI and before the PHR reference time may be based on receiving the second DCI after the PHR reference time.

[0021] In some examples of methods, apparatuses (devices), and non-transitory computer-readable media described herein, the power headroom processing timeline for the first cell may be based on UE processing capabilities for the first cell, a subcarrier spacing (SCS) for the first cell, or a combination thereof. Some examples of methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for the following actions: transmitting a report indicating UE processing capabilities for the first cell, SCS for the first cell, or a combination thereof.

[0022] Some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for the following actions: receiving a second DCI after receiving the first DCI and before the first uplink resource, wherein the first uplink resource at least partially overlaps with the second uplink resource indicated by the second DCI, and discarding at least a portion of the resources from the first uplink resource or the second uplink resource based on the partial overlap, wherein the PHR can be transmitted in the first uplink resource or the second uplink resource based on the discarding.

[0023] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the first priority value of the first uplink resource is different from the second priority value of the second uplink resource. Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, devices, or instructions for the following actions: determining whether to discard the portion of resources from the first uplink resource or from the second uplink resource based on at least one of the first priority value or the second priority value, wherein if the first priority value is less than the second priority value, the portion of resources may be discarded from the first uplink resource, and if the first priority value is greater than the second priority value, the portion of resources may be discarded from the second uplink resource.

[0024] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the first priority value of the first uplink resource is equal to the second priority value of the second uplink resource. Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, devices, or instructions for the following actions: determining whether to discard the portion of resources from the first uplink resource or from the second uplink resource based on preconfiguration, wherein discarding at least the portion of resources from the first uplink resource or the second uplink resource can be based on determining whether to discard the portion of resources from the first uplink resource or from the second uplink resource.

[0025] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the PHR may be transmitted in the second uplink resource based on the discard. Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for the following actions: calculating a first power headroom based on a transmit power indicated by a first DCI, and calculating a second power headroom based on a transmit power indicated by a second DCI.

[0026] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the PHR may be transmitted in the second uplink resource based on the discard. Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for the following actions: using a virtual calculation to calculate the first power headroom, wherein the virtual calculation may be based on one or more preconfigured parameters, one or more parameters indicated by the second DCI, or a combination thereof, and based on the transmit power indicated by the second DCI to calculate the second power headroom.

[0027] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the PHR may be transmitted in the second uplink resource based on the discard. Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for the following actions: determining whether to recalculate the first power headroom based on the power headroom processing timeline for the first cellular cell and the initial codeword of the second uplink resource.

[0028] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, transmitting the PHR may include operations, features, devices, or instructions for the following actions: transmitting the PHR in the initial transmission of a transport block (TB). Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, devices, or instructions for the following actions: determining whether to transmit the PHR in the first uplink resource or the second uplink resource based on whether the first uplink resource or the second uplink resource corresponds to the initial transmission of the TB. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the first uplink resource and the second uplink resource correspond to a retransmission of the TB, wherein transmitting the PHR may include operations, features, devices, or instructions for the following actions: transmitting the PHR in a third uplink resource corresponding to the initial transmission of the TB.

[0029] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, identifying a trigger for transmitting a PHR may include operations, features, apparatuses, or instructions for identifying that a PHR prohibit timer has expired, and determining that a current path loss for at least one cell differs from a reference path loss for the at least one cell by more than a path loss change threshold, wherein the reference path loss corresponds to a most recent PHR transmission for the at least one cell.

[0030] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, identifying a trigger for transmitting a PHR may include operations, features, means, or instructions for identifying that a PHR periodic timer has expired.

[0031] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for the following actions: maintaining the identified trigger upon receiving the first DCI, and canceling the identified trigger based on transmitting the PHR. Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for the following actions: starting a PHR prohibit timer upon canceling the identified trigger.

[0032] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the first cell corresponds to a first processing timeline and the second cell corresponds to a second processing timeline that is shorter than the first processing timeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 and 2

[0013] An example of a wireless communication system that supports a power headroom reporting procedure for multiple cells in accordance with aspects of the present disclosure is illustrated.

[0035] Figures 3 to 5 An example of a power headroom reporting timeline supporting a power headroom reporting procedure for multiple cells in accordance with aspects of the present disclosure is illustrated.

[0036] Figure 6 An example of a process flow supporting a power headroom reporting procedure for multiple cells in accordance with aspects of the present disclosure is illustrated.

[0037] Figure 7 and 8 A block diagram of a device supporting a power headroom reporting procedure for multiple cells is shown in accordance with aspects of the present disclosure.

[0038] Fig. 9 A block diagram of a power headroom reporting module supporting a power headroom reporting procedure for multiple cells is shown in accordance with aspects of the present disclosure.

[0039] Fig.10

[0013] A diagram of a system including a device supporting a power headroom reporting procedure for multiple cells is shown in accordance with aspects of the present disclosure.

[0040] Figures 11 to 14 A flow chart of a method of supporting a power headroom reporting procedure for multiple cells in accordance with aspects of the present disclosure is shown.

[0041] Detailed Description

[0042] In some wireless communication systems (e.g., enhanced ultra-reliable low latency communication (eURLLC) systems), a user equipment (UE) may transmit a power headroom report (PHR) to a base station to indicate the amount of remaining transmit power to be used for the UE in addition to the current transmit power being used by the UE. In some cases, the UE may indicate separate power headroom values ​​for different cells serving the UE. However, the UE may perform a virtual power headroom calculation for one or more cells, which may not be as accurate as a power headroom calculation based on downlink control information (DCI). Additionally, if the UE is scheduled for uplink transmissions for multiple cells in overlapping resources (e.g., time overlap), the UE may fully or partially discard resources for one or more cells. In some cases, the discarding of the resources may cause the UE to discard one or more scheduled PHR transmissions, which may increase the latency involved in reporting the power headroom value. As such, for some cells, the power headroom report for multiple cells may be inaccurate and may be unreliable in situations where resource assignments overlap.

[0043] In some configurations, the UE 115 may report different power headroom measurements that may be for different cells, where the UE 115 may include the different power headroom measurements in the shared PHR. A base station receiving the PHR may use the reported power headroom measurements to estimate a per-cell uplink bandwidth for the UE (e.g., in a particular subframe), where the bandwidth may depend on the available power headroom in some cases.

[0044] The UE may transmit the PHR based on one or more configured PHR triggers for the UE or conditions related to the UE (e.g., a periodic timer, a prohibit timer, or some combination of these or other configured timers or triggers). When the power headroom report is triggered, in some examples, the UE may determine to transmit the PHR in an uplink resource (such as, the next available uplink resource). The UE may receive a first DCI transmission for a first cell scheduling a first uplink resource set for the UE, and the UE may perform (e.g., may initiate) a power headroom calculation based on the DCI. For example, the UE may calculate the power headroom for the first cell using the transmit power indicated in the DCI for the first uplink resource set. In some cases, the UE may perform one or more virtual calculations to determine power headroom measurements for one or more other cells serving the UE (e.g., based on a preconfigured value or parameter in the DCI for the first cell). Additionally or alternatively, the UE may perform power headroom calculations for one or more other cells using the transmit power for a previously or subsequently scheduled uplink resource, or for an ungranted uplink resource.

[0045] To improve the accuracy of one or more of these power headroom calculations, the UE may determine a PHR reference time for updating the power headroom calculation. The PHR reference time may be based on the processing capability of the UE and the first symbol of the scheduled uplink resource. If the UE receives an additional DCI transmission from another cell after receiving the first DCI but before the PHR reference time, the UE may determine that it has sufficient time to perform an updated calculation of the power headroom for the cell. The UE may use the transmit power indicated in the additional DCI to calculate the power headroom for the other cell. Using this DCI-based power headroom calculation may improve the accuracy of the power headroom measurement for the additional cell.

[0046] Additionally or alternatively, for improved PHR transmission reliability, the UE may transmit PHR (including power headroom measurements for multiple cells) in different resource sets. For example, if a first uplink resource set and a second uplink resource set scheduled for the UE overlap (e.g., in time), the UE may fully or partially drop one of the resource sets to avoid collision. However, the UE may transmit PHR in any resource set such that dropping one resource set does not cause the UE to drop PHR transmission. These power headroom reporting techniques may improve the accuracy and reliability of power headroom reporting for multiple cells.

[0047] Various aspects of the present disclosure are initially described in the context of a wireless communication system. Additional aspects of the present disclosure are described with respect to a power headroom reporting timeline and process flow. Various aspects of the present disclosure are further illustrated and described by and with reference to apparatus diagrams, system diagrams, and flow charts related to a power headroom reporting procedure for multiple cells.

[0048] Figure 1 An example of a wireless communication system 100 supporting a power headroom reporting procedure for multiple cells in accordance with various aspects of the present disclosure is illustrated. The wireless communication system 100 includes a base station 105, a UE 115, and a core network 130. In some examples, the wireless communication system 100 may be a long term evolution (LTE) network, an advanced LTE (LTE-A) network, an LTE-A Pro network, or a new radio (NR) network. In some cases, the wireless communication system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission-critical) communications, low latency communications, or communications with low-cost and low-complexity devices.

[0049] The base station 105 may communicate wirelessly with the UE 115 via one or more base station antennas. The base station 105 described herein may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a Node B, an evolved Node B (eNB), a next generation Node B, or a Gigabit Node B (any of which may be referred to as a gNB), a Home Node B, a Home Evolved Node B, or some other suitable terminology. The wireless communication system 100 may include different types of base stations 105 (e.g., macro cell base stations or small cell base stations). The UE 115 described herein may be able to communicate with various types of base stations 105 and network equipment (including macro eNBs, small cell eNBs, gNBs, relay base stations, etc.).

[0050] Each base station 105 may be associated with a particular geographic coverage area 110 in which it supports communications with various UEs 115. Each base station 105 may provide communications coverage for the respective geographic coverage area 110 via a communication link 125, and the communication link 125 between the base station 105 and the UE 115 may utilize one or more carriers. The communication link 125 shown in the wireless communication system 100 may include an uplink transmission from the UE 115 to the base station 105, or a downlink transmission from the base station 105 to the UE 115. Downlink transmissions may also be referred to as forward link transmissions, and uplink transmissions may also be referred to as reverse link transmissions.

[0051] The geographic coverage area 110 of the base station 105 may be divided into sectors that constitute a portion of the geographic coverage area 110, and each sector may be associated with a cellular cell. For example, each base station 105 may provide communication coverage for a macrocellular cell, a small cellular cell, a hotspot, or other types of cellular cells, or various combinations thereof. In some examples, the base station 105 may be mobile and therefore provide communication coverage for a mobile geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, and the overlapping geographic coverage areas 110 associated with different technologies may be supported by the same base station 105 or different base stations 105. The wireless communication system 100 may include, for example, a heterogeneous LTE / LTE-A / LTE-A Pro or NR network, in which different types of base stations 105 provide coverage for various geographic coverage areas 110.

[0052] The term "cell" refers to a logical communication entity for communicating with base station 105 (e.g., on a carrier), and may be associated with an identifier to distinguish adjacent cells operating via the same or different carriers (e.g., physical cell identifier (PCID), virtual cell identifier (VCID)). In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types that may provide access to different types of devices (e.g., machine type communication (MTC), narrowband Internet of Things (NB-IoT), enhanced mobile broadband (eMBB), or others). In some cases, the term "cell" may refer to a portion of a geographic coverage area 110 (e.g., a sector) on which the logical entity operates.

[0053] Each UE 115 can be dispersed throughout the wireless communication system 100, and each UE 115 can be stationary or mobile. UE 115 can also be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable term, wherein "device" can also be referred to as a unit, a station, a terminal, or a client. UE 115 can also be a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, UE 115 can also refer to a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or an MTC device, etc., which can be implemented in various items (such as electrical appliances, vehicles, meters, etc.).

[0054] Some UEs 115, such as MTC or IoT devices, may be low-cost or low-complexity devices and may provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication technology that allows devices to communicate with each other or with a base station 105 without human intervention. In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay the information to a central server or application, which may utilize the information or present the information to a person interacting with the program or application. Some UEs 115 may be designed to collect information or implement automated behavior of machines. Examples of applications for MTC devices include: smart metering, inventory monitoring, water level monitoring, equipment monitoring, health care monitoring, field survival monitoring, weather and geographic event monitoring, queue management and tracking, remote security sensing, physical access control, and transaction-based commercial charging.

[0055] Some UEs 115 may be configured to employ a reduced power consumption mode of operation, such as half-duplex communication (e.g., a mode that supports unidirectional communication via transmission or reception but not simultaneous transmission and reception). In some examples, half-duplex communication may be performed with a reduced peak rate. Other power saving techniques for UE 115 include entering a power saving "deep sleep" mode when not engaged in active communications, or operating over a limited bandwidth (e.g., in accordance with narrowband communications). In some cases, UE 115 may be designed to support critical functions (e.g., mission critical functions), and the wireless communication system 100 may be configured to provide ultra-reliable communications for these functions.

[0056] In some cases, UE 115 may also be able to communicate directly with other UE 115 (e.g., using a peer-to-peer (P2P) or device-to-device (D2D) protocol). One or more UEs in a group of UEs 115 utilizing D2D communication may be within the geographic coverage area 110 of the base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of the base station 105, or may not be able to receive transmissions from the base station 105 for other reasons. In some cases, each group of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system, in which each UE 115 transmits to each other UE 115 in the group. In some cases, the base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between UEs 115 without involving the base station 105.

[0057] The base stations 105 may communicate with the core network 130 and with each other. For example, the base stations 105 may interface with the core network 130 via a backhaul link 132 (e.g., via S1, N2, N3, or other interfaces). The base stations 105 may communicate with each other directly (e.g., directly between the base stations 105) or indirectly (e.g., via the core network 130) on a backhaul link 134 (e.g., via X2, Xn, or other interfaces).

[0058] 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), which may include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one packet data network (PDN) gateway (P-GW). The MME may manage non-access layer (e.g., control plane) functions such as mobility, authentication, and bearer management of UEs 115 served by base stations 105 associated with the EPC. User IP packets may be delivered through the S-GW, which itself may be connected to the P-GW. The P-GW may provide IP address allocation and other functions. The P-GW may be connected to network operator IP services. Operator IP services may include access to the Internet, an intranet, an IP multimedia subsystem (IMS), or packet switched (PS) streaming services.

[0059] At least some network devices (such as base stations 105) may include subcomponents, such as access network entities, which may be examples of access node controllers (ANCs). Each access network entity may communicate with each UE 115 through a number of other access network transport entities, which may be referred to as radio heads, smart radio heads, or transmission / reception points (TRPs). In some configurations, the various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio heads and access network controllers) or merged into a single network device (e.g., base station 105).

[0060] The wireless communication system 100 can operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). In general, the 300 MHz to 3 GHz region is referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelengths are in the range of from about 1 decimeter to 1 meter long. UHF waves can be blocked or redirected by buildings and environmental features. However, these waves can penetrate various structures sufficiently for macro cells to provide services to UEs 115 located indoors. Transmission of UHF waves can be associated with smaller antennas and shorter ranges (e.g., less than 100 km) compared to transmission using lower frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

[0061] The wireless communication system 100 may also operate in the Super High Frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as centimeter bands. The SHF region includes frequency bands that may be opportunistically used by devices that may be able to tolerate interference from other users, such as the 5 GHz Industrial, Scientific, and Medical (ISM) band.

[0062] The wireless communication system 100 may also operate in the extremely high frequency (EHF) division of the spectrum (e.g., from 30 GHz to 300 GHz), which is also referred to as the millimeter band. In some examples, the wireless communication system 100 may support millimeter wave (mmW) communications between the UE 115 and the base station 105, and the EHF antenna of the corresponding device may be even smaller and more closely spaced than the UHF antenna. In some cases, this may facilitate the use of antenna arrays within the UE 115. However, the propagation of EHF transmissions may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. The technology disclosed herein may be adopted across transmissions using one or more different frequency divisions, and the use of frequency bands specified across these frequency divisions may differ by country or regulatory agency.

[0063] In some cases, the wireless communication system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communication system 100 may employ license assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band (such as a 5 GHz ISM band). When operating in an unlicensed radio frequency spectrum band, wireless devices (such as base stations 105 and UE 115) may employ a listen-before-talk (LBT) procedure to ensure that the frequency channel is clear before transmitting data. In some cases, operations in unlicensed bands may be based on carrier aggregation configuration (e.g., LAA) in coordination with component carriers operating in licensed bands. Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, peer-to-peer transmissions, or a combination of these. Duplexing in unlicensed spectrum may be based on frequency division duplexing (FDD), time division duplexing (TDD), or a combination of the two.

[0064] In some examples, the base station 105 or the UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communication, or beamforming. For example, the wireless communication system 100 may use a transmission scheme between a transmitting device (e.g., the base station 105) and a receiving device (e.g., the UE 115), wherein the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas. MIMO communication may employ multipath signal propagation to increase spectral efficiency by transmitting or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing. For example, the transmitting device may transmit multiple signals via different antennas or different antenna combinations. Similarly, the receiving device may receive multiple signals via different antennas or different antenna combinations. Each of these multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO technology includes single-user MIMO (SU-MIMO), in which multiple spatial layers are transmitted to the same receiving device, and multi-user MIMO (MU-MIMO), in which multiple spatial layers are transmitted to multiple devices.

[0065] 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 or a UE 115) to shape or direct an antenna beam (e.g., a transmit beam or a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining signals communicated via antenna elements of an antenna array so that signals propagating at a particular orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals communicated via antenna elements may include the transmitting device or the receiving device applying a specific amplitude and phase shift to the signal carried via each antenna element associated with the device. The adjustments associated with each antenna element may be defined by a set of beamforming weights associated with a particular orientation (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other orientation).

[0066] In one example, the base station 105 may use multiple antennas or antenna arrays to perform beamforming operations for directional communication with the UE 115. For example, some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted multiple times by the base station 105 in different directions, which may include a signal being transmitted according to different beamforming weight sets associated with different transmission directions. The transmissions in different beam directions may be used (e.g., by the base station 105 or a receiving device, such as the UE 115) to identify the beam direction used by the base station 105 for subsequent transmission and / or reception.

[0067] Some signals, such as data signals associated with a particular recipient device, may be transmitted by base station 105 in a single beam direction (e.g., a direction associated with a recipient device, such as UE 115). In some examples, a beam direction associated with transmissions along a single beam direction may be determined based at least in part on signals transmitted in different beam directions. For example, UE 115 may receive one or more signals transmitted by base station 105 in different directions, and UE 115 may report to base station 105 an indication of the signals received by it with the highest signal quality or other acceptable signal quality. Although these techniques are described with reference to signals transmitted by base station 105 in one or more directions, UE 115 may use similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction used by UE 115 for subsequent transmission or reception) or for transmitting signals in a single direction (e.g., for transmitting data to a recipient device).

[0068] A receiving device (e.g., UE 115, which may be an example of a mmW receiving device) may try multiple receive beams when receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from base station 105. For example, the receiving device may try multiple receive directions by receiving via different antenna subarrays, processing received signals according to different antenna subarrays, receiving according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, or processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as "listening" according to different receive beams or receive directions. In some examples, the receiving device may use a single receive beam to receive along a single beam direction (e.g., when receiving a data signal). The single receive beam may be aligned on a beam direction determined at least in part based on listening according to different receive beam directions (e.g., a beam direction determined to have the highest signal strength, highest signal-to-noise ratio, or other acceptable signal quality based at least in part on listening according to multiple beam directions).

[0069] In some cases, the antennas of a base station 105 or a UE 115 may be located within one or more antenna arrays that 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 cases, the antennas or antenna arrays associated with a base station 105 may be located at different geographic locations. A base station 105 may have an antenna array having several rows and columns of antenna ports that the base station 105 may use to support beamforming for communications with a UE 115. Likewise, a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations.

[0070] In some cases, the wireless communication system 100 can be a packet-based network that operates according to a layered protocol stack. In the user plane, the communication of the bearer or packet data convergence protocol (PDCP) layer can be IP-based. The radio link control (RLC) layer can perform packet segmentation and reassembly to communicate on the logical channel. The media access control (MAC) layer can perform priority handling and multiplex logical channels into transport channels. The MAC layer can also use hybrid automatic repeat request (HARQ) to provide retransmission of the MAC layer, thereby improving link efficiency. In the control plane, the radio resource control (RRC) protocol layer can provide the establishment, configuration and maintenance of the RRC connection of the radio bearer supporting user plane data between the UE 115 and the base station 105 or the core network 130. In the physical layer, the transport channel can be mapped to the physical channel.

[0071] In some cases, UE 115 and base station 105 may support retransmission of data to increase the likelihood that the data is successfully received. HARQ feedback is a technique that increases the likelihood of correctly receiving data on communication link 125. HARQ may include a combination of error detection (e.g., using cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ can improve the throughput of the MAC layer in poor radio conditions (e.g., signal-to-noise ratio conditions). In some cases, a wireless device may support simultaneous slot HARQ feedback, where the device may provide HARQ feedback in a specific time slot for data received in a previous symbol in the time slot. In other cases, the device may provide HARQ feedback in a subsequent time slot or according to some other time interval.

[0072] The time interval in LTE or NR can be represented by a basic time unit (which may refer to a sampling period T for example). s =1 / 30,720,000 seconds). The time intervals of the communication resources may be organized according to radio frames each having a duration of 10 milliseconds (ms), where the frame period may be expressed as T f =307,200Ts . A radio frame may be identified by a system frame number (SFN) ranging from 0 to 1023. Each frame may include 10 subframes numbered from 0 to 9, and each subframe may have a duration of 1 ms. A subframe may be further divided into 2 slots, each slot having a duration of 0.5 ms, and each slot may contain 6 or 7 modulation symbol periods (e.g., depending on the length of a cyclic prefix prepended to each symbol period). Excluding the cyclic prefix, each symbol period may contain 2048 sampling periods. In some cases, a subframe may be the minimum scheduling unit of the wireless communication system 100 and may be referred to as a transmission time interval (TTI). In other cases, the minimum scheduling unit of the wireless communication system 100 may be shorter than a subframe or may be dynamically selected (e.g., in a burst of a shortened TTI (sTTI) or in a selected component carrier using sTTI).

[0073] In some wireless communication systems, a time slot may be further divided into a plurality of mini-slots containing one or more symbols. In some instances, a symbol of a mini-slot or a mini-slot may be the minimum scheduling unit. For example, each symbol may vary in duration depending on the subcarrier spacing or the operating frequency band. Further, some wireless communication systems may implement time slot aggregation, wherein a plurality of time slots or mini-slots are aggregated together and used for communication between UE 115 and base station 105.

[0074] The term "carrier" refers to a set of radio frequency spectrum resources having a defined physical layer structure for supporting communications on the communication link 125. For example, a carrier of the communication link 125 may include a portion of a radio frequency spectrum band that operates according to a physical layer channel for a given radio access technology. Each physical layer channel may carry user data, control information, or other signaling. A carrier may be associated with a predefined frequency channel (e.g., an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) Absolute Radio Frequency Channel Number (EARFCN)) and may be located according to a channel grid for discovery by a UE 115. A carrier may be downlink or uplink (e.g., in FDD mode), or configured to carry downlink communications and uplink communications (e.g., in TDD mode). In some examples, a signal waveform transmitted on a carrier may include multiple subcarriers (e.g., using a multi-carrier modulation (MCM) technique such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)).

[0075] For different radio access technologies (e.g., LTE, LTE-A, LTE-A Pro, NR), the organizational structure of the carrier can be different. For example, the communication on the carrier can be organized according to TTIs or time slots, each of which can include user data and control information or signaling to support decoding of the user data. The carrier can also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc.) and control signaling to coordinate the operation of the carrier. In some examples (e.g., in a carrier aggregation configuration), the carrier may also have acquisition signaling or control signaling to coordinate the operation of other carriers.

[0076] Physical channels may be multiplexed on a carrier according to various techniques. Physical control channels and physical data channels may be multiplexed on a downlink carrier, for example, using a time division multiplexing (TDM) technique, a frequency division multiplexing (FDM) technique, or a hybrid TDM-FDM technique. In some examples, control information transmitted in a physical control channel may be distributed in a cascaded manner between different control regions (e.g., between a common control region or a common search space and one or more UE-specific control regions or UE-specific search spaces).

[0077] 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 the "system bandwidth" of the carrier or wireless communication system 100. For example, the carrier bandwidth may be one of several predetermined bandwidths of a carrier for a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). In some examples, each served UE 115 may be configured to operate on part or all of the carrier bandwidth. In other examples, some UEs 115 may be configured to operate using a narrowband protocol type associated with a predefined portion or range within a carrier (e.g., a set of subcarriers or resource blocks (RBs)) (e.g., an "in-band" deployment of a narrowband protocol type).

[0078] In a system using MCM technology, a resource element may include a symbol period (e.g., the duration of a modulation symbol) and a subcarrier, where the symbol period and the 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). Thus, the more resource elements received by UE 115 and the higher the order of the modulation scheme, the higher the data rate of UE 115 can be. In a MIMO system, wireless communication resources may refer to a combination of radio frequency spectrum resources, time resources, and space resources (e.g., space layers), and the use of multiple space layers may further increase the data rate of communication with UE 115.

[0079] A device (e.g., base station 105 or UE 115) of wireless communication system 100 may have a hardware configuration that supports communication on a particular carrier bandwidth, or may be configurable to support communication on one of a set of carrier bandwidths. In some examples, wireless communication system 100 may include base stations 105 and / or UEs 115 that support simultaneous communication via carriers associated with more than one different carrier bandwidths.

[0080] The wireless communication system 100 may support communication with the UE 115 on multiple cells or carriers, a feature that may be referred to as carrier aggregation or multi-carrier operation. The 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 FDD and TDD component carriers.

[0081] In some cases, the wireless communication system 100 may utilize an enhanced component carrier (eCC). An eCC may be characterized by one or more features including a wider carrier or frequency channel bandwidth, a shorter symbol duration, a shorter TTI duration, or a modified control channel configuration. In some cases, an eCC may be associated with a carrier aggregation configuration or a dual connectivity configuration (e.g., when multiple serving cells have suboptimal or non-ideal backhaul links). An eCC may also be configured for use in an unlicensed spectrum or a shared spectrum (e.g., where more than one operator is allowed to use the spectrum). An eCC characterized by a wide carrier bandwidth may include one or more segments that may be utilized by a UE 115 that is not capable of monitoring the entire carrier bandwidth or is otherwise configured to use a limited carrier bandwidth (e.g., to save power).

[0082] In some cases, an eCC may utilize a different symbol duration than other component carriers, which may include using a reduced symbol duration compared to the symbol duration of other component carriers. A shorter symbol duration may be associated with an increased spacing between adjacent subcarriers. A device utilizing an eCC (such as a UE 115 or a base station 105) may transmit a wideband signal (e.g., according to a frequency channel or carrier bandwidth of 20, 40, 60, 80 MHz, etc.) with a reduced symbol duration (e.g., 16.67 microseconds). A TTI in an eCC may include one or more symbol periods. In some cases, the TTI duration (i.e., the number of symbol periods in a TTI) may be variable.

[0083] The wireless communication system 100 may be an NR system that may utilize any combination of licensed, shared, and unlicensed spectrum bands, etc. The flexibility of eCC symbol duration and subcarrier spacing may allow eCC to be used across multiple spectrums. In some examples, NR shared spectrum may improve spectrum utilization and spectrum efficiency, particularly through dynamic vertical (e.g., across frequency domain) and horizontal (e.g., across time domain) sharing of resources.

[0084] In some wireless communication systems 100 (e.g., eURLLC systems), the UE 115 may report power headroom measurements for one or more cells serving the UE 115 to the base station 105. In some configurations, the UE 115 may report different power headroom measurements for different cells, and the UE 115 may include the different power headroom measurements in a single PHR. The base station 105 receiving the PHR may use the reported power headroom measurements to estimate a per-cell uplink bandwidth for the UE 115, where the bandwidth may depend on the indicated power headroom.

[0085] UE 115 may transmit a PHR based on one or more PHR triggers configured for UE 115. When a power headroom report is triggered (e.g., at UE 115), UE 115 may determine to transmit a PHR (e.g., in the next available uplink resource). UE 115 may receive a first DCI transmission for a first cell that schedules a first uplink resource set for UE 115 (e.g., from base station 105), and UE 115 may initiate a power headroom calculation based on the DCI. For example, UE 115 may calculate the power headroom for the first cell using the transmit power indicated in the DCI for the first uplink resource set. In some cases, UE 115 may perform several calculations (such as virtual calculations) to determine power headroom measurements for other cells serving UE 115 (e.g., based on preconfigured values ​​or parameters in the DCI for the first cell). Additionally or alternatively, the UE 115 may perform power headroom calculations for other cells using transmit power for previously scheduled uplink resources, transmit power for ungranted uplink resources, etc.

[0086] To improve the accuracy of one or more of these power headroom calculations, the UE 115 may determine a PHR reference time (e.g., a DCI reception period) for updating the power headroom calculations. The PHR reference time may be based on the processing capabilities of the UE 115 and the first symbol of the scheduled uplink resources. If the UE 115 receives an additional DCI transmission from another cell (e.g., from the same or different base station 105) after receiving the first DCI but before the PHR reference time, the UE 115 may determine that it has sufficient time to perform an updated calculation of the power headroom for the cell. The UE 115 may calculate the power headroom for the other cell using the transmit power indicated in the additional DCI. Using this DCI-based power headroom calculation may improve the accuracy of the power headroom measurement for the additional cell.

[0087] Additionally or alternatively, for improved PHR transmission reliability, UE 115 may switch (e.g., dynamically switch) uplink resources used to transmit PHR to increase the likelihood that PHR is transmitted in a timely manner. For example, if a first uplink resource set and a second uplink resource set scheduled for UE 115 overlap (e.g., in time), UE 115 may fully or partially discard one of the resource sets to avoid conflict (e.g., based on the priority of each resource set). UE 115 may transmit PHR in any resource set, but discarding one resource set does not cause UE 115 to refrain from transmitting PHR transmission. These power headroom reporting techniques may improve the accuracy and reliability of UE 115 reporting power headroom measurements for multiple cells.

[0088] Figure 2 An example of a wireless communication system 200 that supports a power headroom reporting procedure for multiple cells in accordance with various aspects of the present disclosure is illustrated. The wireless communication system 200 may include a base station 105-a and a UE 115-a, which may be reference Figure 1 Examples of corresponding devices described. The base station 105-a can support a first cell 225-a and a second cell 225-b, where each of these cells 225 can serve at least the UE 115-a. Alternatively, separate base stations 105 can support the first cell 225-a and the second cell 225-b, where the separate base stations 105 can be linked via a backhaul. In some cases, the UE 115-a can transmit a PHR 220 containing power headroom measurements for both the cell 225-a and the cell 225-b.

[0089] The power headroom generally relates to a measurement of the available transmit power left for the UE 115 (e.g., in addition to the current transmit power used by the UE 115 for the current transmission). The UE 115 may support multiple types of power headroom measurements. For example, a Type 1 power headroom measurement may refer to the difference between the nominal UE maximum transmit power and the estimated current transmit power (e.g., the transmit power of the uplink shared channel (SCH) transmission per activated serving cell).

[0090] Type 2 power headroom may refer to the difference between the nominal UE maximum transmit power and the estimated power of uplink SCH and physical uplink control channel (PUCCH) transmissions on another MAC entity cell (e.g., special cell, serving cell, etc.). In Type 2 power headroom, in the case of E-UTRA NR dual connectivity (EN-DC), the other MAC entity may be an E-UTRA MAC entity.

[0091] Type 3 power headroom may refer to the difference between a nominal UE maximum transmit power and an estimated power of a sounding reference signal (SRS) transmission per activated serving cell. In some cases, additional or alternative types of power headroom measurements may be defined for a system. In a power headroom reporting procedure, a UE 115 (e.g., UE 115-a) may transmit a PHR 220 to a serving base station 105 (e.g., base station 105-a) to indicate power headroom information, such as one or more of these types of power headroom measurements. The PHR 220 may be an example of a MAC control element (CE) and may be transmitted in a physical uplink shared channel (PUSCH) transmission.

[0092] When power headroom reporting is triggered, the UE 115-a may calculate one or more power headroom measurements to include in the PHR 220 for transmissions to the base station 105-a. For example, the power headroom measurement (e.g., type 1 power headroom) may correspond to the UE maximum available transmit power minus the power scheduled for PUSCH transmission, as described in Equation 1 below:

[0093] Power headroom = UE maximum transmit power - PUSCH power (1)

[0094] UE 115-a may calculate the power headroom based on information included in DCI 215 received from base station 105-a. DCI 215 transmission may allocate uplink resources (e.g., PUSCH resources) to UE 115 and may indicate a scheduled transmit power to be achieved by UE 115 in the scheduled PUSCH resources. UE 115 may then transmit PHR 220 to base station 105 and may include the calculated power headroom value(s) in PHR 220.

[0095] The PHR 220 may be triggered in a variety of ways, including but not limited to different conditions. In one example, if a periodic timer expires (e.g., phr-PeriodicTimer), the PHR 220 may be triggered. This may maintain a maximum time gap between PHRs 220 for the UE 115-a (e.g., where the maximum gap corresponds to a reset value configured for the periodic timer).

[0096] In another example, a PHR may be triggered if a prohibition timer (e.g., phr-ProhibitTimer) expires and if the path loss of a path loss reference cell has changed by more than a threshold. In this example, the prohibition timer may trigger the transmission of a PHR 220 regardless of whether the prohibition timer expires before or after the path loss difference satisfies the threshold. The path loss change threshold may be defined as a phr-Tx-PowerFactorChange threshold and, in some cases, may be measured in decibels (dB). The UE 115-a may check the path loss difference of each activated serving cell 225 for any MAC entity operating as a path loss reference that has uplink resources allocated for a new transmission. If at least one of these activated serving cells 225 has a path loss change greater than a threshold since the last transmission of the PHR 220 in the corresponding MAC entity and the prohibition timer has expired, the PHR 220 transmission may be triggered at the UE 115-a.

[0097] Specifically, the change in path loss for one of the serving cells 225 may correspond to the difference between the path loss measured at the current time on the first current path loss reference cell and the path loss measured at the transmission time of the previous (e.g., last) transmission of the PHR 220 for the second path loss reference cell used at that time. The path loss reference cell may be the first cell 225 used for the measurement at the first time (e.g., the current time) and may be the second cell 225 used for the measurement at the second time (e.g., the transmission time), or the path loss reference cell may be the same cell 225 at both times.

[0098] In this example of using an inhibit timer to trigger the PHR 220, once the first PHR 220 has been triggered or transmitted, the PHR 220 may not be triggered again until the inhibit timer expires. In situations where the path loss measurement has changed dramatically (e.g., exceeded a threshold), the inhibit timer may allow the UE 115-a to send the PHR 220 at shorter intervals than the periodic timer. The periodic timer and the inhibit timer are two examples of possible triggers for the transmission of the PHR 220. However, additional or alternative triggers and / or timers may be implemented by the UE 115-a to trigger the transmission of the PHR 220 to the base station 105-a.

[0099] The UE 115-a may be configured (e.g., the base station 105-a may configure the UE 115-a) to calculate one or more power headroom measurements for the configured uplink cells 225. In a first example, the UE 115-a may be configured in a "single" configuration (e.g., a single PHR mode or a single PHR format). In the single configuration, if power headroom reporting is triggered, the UE 115-a may calculate the power headroom and transmit the PHR 220 for one cell 225 (e.g., a primary cell (PCell) of the UE 115-a, such as the cell 225-a).

[0100] In a second example, the UE 115-a may be configured in a "multiple" configuration (e.g., a multiple PHR mode). In a multiple configuration scenario, if a power headroom report for even one cell 225 is triggered, the UE 115-a may report a PHR 220 including power headrooms for multiple (e.g., all) configured uplink cells 225 (e.g., cells 225-a and 225-b) of a MAC entity. Whether the UE 115-a is configured for a single PHR 220 (e.g., a PHR 220 containing a single power headroom measurement) or multiple PHRs 220 (e.g., a PHR 220 containing multiple power headroom measurements) may be determined by the base station 105-a. The base station 105-a may transmit an indication of at least one configuration (e.g., a single or multiple PHR configuration) to the UE 115-a, and the UE 115-a may operate according to the signaled configuration.

[0101] In some systems, the UE 115 may be configured to include multiple power headroom measurements in the same PHR. The UE 115 may calculate power headroom values ​​for multiple cells and may transmit a PHR (e.g., a Type 1 PHR) to one or more base stations 105, wherein the PHR includes power headroom values ​​for multiple cells. However, the UE 115 may perform one or more "virtual" calculations for the power headroom calculations for the multiple cells, thereby limiting the accuracy of the power headroom measurements.

[0102] For example, the UE 115 may calculate a first power headroom measurement based on an assigned transmit power for a first set of PUSCH resources, where the assigned transmit power may be indicated in a first received DCI. The first set of PUSCH resources may correspond to an initial transmission of a first transport block (TB) on a first active uplink bandwidth part (BWP) for a first carrier of a first serving cell. The UE 115 may also receive a second DCI that schedules a second PUSCH transmission on a second active BWP for a second carrier of a second serving cell, where the second DCI may indicate a transmit power for the second PUSCH transmission. The second PUSCH resources may overlap (e.g., in time) with the first PUSCH resources. If the second DCI is received after the first DCI, the UE may not consider the transmit power indicated in the second DCI when calculating the power headroom for the second cell.

[0103] For example, if the second DCI corresponds to a first DCI format (e.g., DCI format 0_0 or 0_1) in a physical downlink control channel (PDCCH) received in a second PDCCH monitoring opportunity, and if the second PDCCH monitoring opportunity occurs after a first PDCCH monitoring opportunity in which UE 115 detects the earliest DCI format (e.g., 0_0 or 0_1) that schedules an initial transmission of a TB after a PHR transmission is triggered, the second DCI may not affect the power headroom calculation. That is, the first DCI after the PHR trigger may initiate the power headroom calculation for the PHR for each cell, and thus the DCI received after the first DCI may not be used for the power headroom calculation that has already been performed.

[0104] In these situations (e.g., if a first DCI is received in a first monitoring opportunity for a first cell, power headroom calculations for multiple cells are initiated), power headroom calculations for additional cells beyond the first cell may be performed based on a virtual calculation, as opposed to an "actual" calculation that takes into account the currently assigned DCI transmit power. In some examples, the virtual calculation of power headroom may involve the UE 115 determining an estimate of power headroom for a different cell based on preconfigured values ​​or parameters in the DCI for a cell (e.g., where the UE 115 estimates the transmit power for the cell). In some situations, the estimate of transmit power may be based on a reference PUSCH or a non-grant PUSCH, rather than the currently scheduled PUSCH. In some examples, the actual calculation of power headroom may involve the UE 115 subtracting the actual transmit power indicated in the DCI transmission for the PUSCH resources from the maximum available transmit power of the UE 115.

[0105] In some cases, for such systems, PUSCH resources for different cells may overlap in time. If UE 115 does not support simultaneous or concurrent transmission in multiple PUSCH resource sets, UE 115 may fully or partially drop one or more resource sets. If a PHR is scheduled for transmission in a first PUSCH based on a DCI received in a first PDCCH monitoring opportunity and UE 115 drops resources from the first PUSCH, UE 115 may be unable to send a PHR to base station 105. This problem may be more severe in the case where the second PUSCH resource is associated with a packet having a relatively higher priority than the packet associated with the first PUSCH resource.

[0106] For example, the second PUSCH resource may correspond to an ultra-reliable low latency communication (URLLC) transmission, and the first PUSCH resource may correspond to an eMBB transmission. In order for the base station 105 to support URLLC, the base station 105 may use accurate power headroom information received in a timely manner (e.g., within a threshold response time). If the PHR transmission is discarded based on discarding the first PUSCH resource, the base station 105 may not be able to fully support URLLC reception due to not receiving power headroom measurements. In this way, these systems may result in inaccurate power headroom measurements for certain cells, and slow power headroom reporting in situations where PUSCH resources with scheduled PHRs are discarded.

[0107] In contrast, the wireless communication system 200 may support one or more operations for improved power headroom reporting for multiple cells 225. The UE 115-a may identify a trigger for transmitting a PHR 220 (e.g., based on a PHR timer). Based on the PHR trigger, the UE 115-a may determine to transmit the PHR 220 in the next available uplink resource. The UE 115-a may receive a first DCI 215-a transmission for a first cell 225-a on a first carrier 205-a (e.g., from a base station 105-a). The first DCI 215-a may schedule a first uplink resource set (e.g., PUSCH resources) for the UE 115-a, and the UE 115-a may initiate a power headroom calculation based on the first DCI 215-a. For example, the UE 115-a may calculate the power headroom for the first cell 235 using the transmit power indicated in the first DCI 215 for the first uplink resource set. In some cases, the UE 115 - a may perform several calculations (eg, virtual calculations) to determine power headroom measurements for other cells 225 (eg, a second cell 225 - b ) serving the UE 115 - a.

[0108] In a first operation, to improve the accuracy of one or more of these power headroom calculations, the UE 115-a may determine a PHR reference time (e.g., a DCI 215 reception period) for updating the power headroom calculations. The PHR reference time may be based on the processing capability of the UE 115-a and the first symbol of the scheduled uplink resource. If the UE 115-a receives additional DCI 215-b (e.g., from another cell 225-b) on a second carrier 205-b (e.g., from the same or different base station 105) after receiving the first DCI 215-a and before the PHR reference time, the UE 115-a may determine whether it has sufficient time to perform the updated calculation of the power headroom for the second cell 225-b. The UE 115-a may calculate the power headroom for the second cell 225-b using the transmit power indicated in the second DCI 215-b. Using the DCI-based power headroom calculation may improve the accuracy of the power headroom measurements for the additional cells 225-b. The UE 115-a may transmit one or more PHRs 220 containing power headroom measurements for at least the first cell 225-a and the second cell 225b to the base station 105-a on the uplink channel 210 using scheduled uplink resources (e.g., a PUSCH resource set scheduled by the first DCI 215-a or the second DCI 215-b).

[0109] Additionally or alternatively, in operation, UE 115-a may improve PHR transmission reliability by supporting switching of uplink resources used to transmit PHR 220 to increase the likelihood that PHR 220 is transmitted in a timely manner. For example, if a first uplink resource set scheduled by DCI 215-a and a second uplink resource set scheduled by DCI 215-b for UE 115-a overlap in time, UE 115-a may fully or partially discard one resource set (e.g., based on a priority of at least one resource set). However, UE 115-a may transmit PHR 220 in either resource set, such that discarding one resource set does not cause UE 115-a to suppress transmission of PHR 220 in at least one of the scheduled PUSCH resource sets. In this manner, UE 115-a may transmit PHR 220 in the first uplink resource or the second uplink resource. The base station 105 - a may receive the PHR 220 and may support URLLC operations based on the received power headroom measurements for the first cell 225 - a and the second cell 225 - b .

[0110] Figure 3An example of a power headroom reporting timeline 300 that supports a power headroom reporting procedure for multiple cells in accordance with aspects of the present disclosure is illustrated. The power headroom reporting timeline 300 illustrates UE 115 operations for reporting power headroom measurements for multiple cells 305 (e.g., a first cell 305-a and a second cell 305-b). The UE 115 may be as described with reference to Figure 1 and 2 An example of a described UE 115. According to the power headroom reporting timeline 300, the UE 115 may perform a number of calculations (eg, "actual" power headroom calculations) to improve power headroom reporting accuracy.

[0111] The UE 115 may identify a PHR trigger 310. In some cases, the PHR trigger 310 may be associated with a particular cell 305. In other cases, the PHR trigger 310 may correspond to multiple (e.g., all) cells 305 serving the UE 115 (e.g., for a particular MAC entity). Based on the identified PHR trigger 310, the UE 115 may schedule a PHR transmission in uplink resources (e.g., PUSCH resources 325). In one example, the UE 115 may receive a DCI 315-a in a first monitoring opportunity for a first cell 305-a. The DCI 315-a may indicate scheduling of uplink transmissions for the UE 115 in the PUSCH resources 325-a. The UE 115 may determine to transmit a PHR in these scheduled PUSCH resources 325-a based on the PHR trigger 310 and the received DCI 315-a.

[0112] In some cases, rather than using the first DCI 315 reception point as a reference point for power headroom calculation, the UE 115 may identify a PHR timing capability (e.g., UE-specific PHR timing capability, cell-specific PHR timing capability, subcarrier spacing (SCS)-dependent PHR timing capability, etc.) for power headroom calculation. In some cases, the PHR timing capability may be equal to or a function of a PUSCH preparation timeline (N2), which may refer to the time for the UE 115 to process the DCI 315 and prepare for uplink transmission between the last symbol of the DCI 315 and the first symbol of the corresponding PUSCH resource 325. In some examples, the value of N2 may be specific to the cell 305 in which the UE 115 reports the PHR.

[0113] Additionally or alternatively, the PHR timing capability may depend on other internal processing capabilities of the UE 115. The PHR timing capability may correspond to an amount of time 320 used by the UE 115 to calculate a power headroom measurement for the cell 305 based on the transmit power allocated to the PUSCH resource 325. Using the PHR timing capability and the initial symbol of the scheduled PUSCH resource 325-a, the UE 115 may determine a reference point in time marking a deadline for the UE 115 to receive a DCI 315 and still support the calculation of the power headroom based on the received DCI 315. The reference point based on the PHR timing capability may be after the first DCI 315 reception time. As such, the first DCI 315-a may trigger the UE 115 to begin preparing for the PHR, but when calculating power headroom measurements for other cells for the PHR, the UE 115 may account for the transmit power indicated in the DCI 315 received after the first DCI 315-a (but before the identified PHR timing reference point). This approach to power headroom calculation allows for a gap between the two DCIs 315, thereby supporting PHR reporting of a more accurate power headroom measurement for the second cell 305-b (e.g., because the power headroom for the second cell 305-b can be determined using a “real” power headroom calculation, rather than a “virtual” power headroom calculation).

[0114] For example, a first DCI 315-a and a second DCI 315-b may be received by a UE 115, wherein the second DCI 315-b is received after the first DCI 315-a. The first DCI 315-a may assign a first PUSCH resource 325-a to the UE 115 for uplink transmissions for the first cell 305-a, while the second DCI 315-b may assign a second PUSCH resource 325-b to the UE 115 for uplink transmissions for the second cell 305-b. Once the UE 115 receives the first DCI 315-a, the UE 115 may use the information in the first DCI 315-a (e.g., transmission parameters of the PUSCH resource 325-a) to calculate a power headroom measurement for the first cell 305-a. Additionally, the UE 115 may begin a virtual power headroom calculation for the second cell 305-b. The UE 115 may schedule transmission of a PHR for these first PUSCH resources 325 - a .

[0115] When calculating the power headroom for the first cell 305-a, the UE 115 may receive a second DCI 315-b indicating a second PUSCH resource 325-b. The UE 115 may determine whether the second DCI 315-b is received before the PHR timing reference point (e.g., whether the second DCI 315-b is received at least a time amount 320 ahead of the first codeword of the scheduled PUSCH resource 325-a). If so, the UE 115 may use the transmission parameters of the second PUSCH resource 325-b (which in some examples may be indicated by the second DCI 315-b) to calculate the power headroom for the second cell 305-b. Because the actual assigned transmit power can be used for the calculation, the calculation based on the actual grant can result in a more accurate power headroom measurement for the second cell 305-b compared to the virtual calculation.

[0116] In some cases, reference Figure 3 The described operations may be used for scenarios where the UE 115 uses two PUSCH resource sets 325. For example, the UE 115 may transmit on the uplink simultaneously in the first PUSCH resource 325-a and the second PUSCH resource 325-b (e.g., if the component carriers of the cell 305 are inter-band or intra-band contiguous). Alternatively, the described operations may be used in scenarios where resources are dropped from either of the PUSCH resource sets 325 (e.g., because the UE 115 does not support concurrent transmissions in the two cells 305).

[0117] Figure 4 An example of a power headroom reporting timeline 400 that supports a power headroom reporting procedure for multiple cells in accordance with aspects of the present disclosure is illustrated. The power headroom reporting timeline 400 illustrates UE 115 operations for reporting power headroom measurements for multiple cells 405 (e.g., a first cell 405-a and a second cell 405-b). The UE 115 may be as described with reference to Figures 1 to 3 An example of a described UE 115. According to the power headroom reporting timeline 400, if the DCI 415 for the cell 405 is not received before the PHR timing capability reference point, the UE 115 may handle the power headroom calculation for the cell 405.

[0118] The UE 115 may identify a PHR trigger 410. Based on the identified PHR trigger 410, the UE 115 may schedule a PHR transmission in uplink resources (e.g., PUSCH resources 425). In one example, the UE 115 may receive a DCI 415-a in a first monitoring opportunity for a first cell 405-a (e.g., on a first carrier). The DCI 415-a may indicate scheduling of uplink transmissions for the UE 115 in the PUSCH resources 425-a. The UE 115 may determine to transmit a PHR in these scheduled PUSCH resources 425-a based on the PHR trigger 410 and the received DCI 415-a.

[0119] The UE 115 may determine whether a DCI 415 for the second cell 405-b is received after the first DCI 415-a and before the PHR timing reference point. The PHR timing reference point may be determined by the UE 115, as described above with reference to Figure 3 As described. In some cases, the UE 115 does not receive DCI 415 for the second cell 405-b while there is a remaining amount of time 420 before the PHR transmission in the PUSCH resource 425-a. In one example, the UE 115 may not receive any DCI 415 for the second cell 405-b before the transmission of the PHR. In another example, the UE 115 may receive the second DCI 415 for the second cell 405-b when the UE 115 does not have sufficient time to process the DCI 415 and calculate the power headroom measurement based on the information in the DCI 415 (e.g., the second DCI 415-b is received after the PHR timing reference point).

[0120] The amount of time 420 required to process the second DCI 415 for the second cell 405-b may be a predefined value T proc,2 In such a scenario, the UE 115 calculation of the power headroom for the second cell 405-b may not be based on the scheduled PUSCH 425-b for the second cell 405-b (e.g., based on the transmit power indicated in the DCI 415-b). Instead, the UE 115 may use other values ​​or parameters to determine the power headroom for the second cell 405-b such that the UE 115 may include a power headroom measurement for the second cell 405-b in the PHR transmitted in the first PUSCH resource 425-a.

[0121] In a first example, the UE 115 may calculate a virtual power headroom for the second cell 405-b and may include the virtual power headroom calculation result in a PHR transmitted in the first PUSCH resource 425-a (e.g., together with a power headroom measurement for the first cell 405-a based on the first DCI 415-a and the indicated transmit power for the first PUSCH).

[0122] In a second example, the UE 115 may calculate the power headroom based on a previous PUSCH. The UE 115 may be assigned PUSCH resources 425 for the second cell 405-b prior to receiving the first DCI 415-a, prior to the PHR trigger 410, or both. The UE 115 may calculate the power headroom for the second cell 405-b using the transmit power for these previously assigned PUSCH resources 425 (e.g., the most recent PUSCH transmitted on the cell 405-b before the first DCI 415-a scheduling the PUSCH resources 425-a on the cell 405-a was received).

[0123] In a third example, the UE 115 may calculate the power headroom based on the non-grant PUSCH resources 425. The UE 115 may be configured to have non-grant PUSCH resources 425 for the cell 405-b, wherein the UE 115 is configured to have a transmit power for each of these non-grant resource sets. The UE 115 may calculate the power headroom for the second cell 405-b using the transmit power for the non-grant resources scheduled before the first DCI 415-a was received (e.g., the most recent non-grant PUSCH opportunity) or scheduled after the first PUSCH resource 425-a, the PUSCH resource 425-b, or both (e.g., the next non-grant PUSCH opportunity). In some cases, if no DCI 415 for the second cell 405-b is received between the reception of the first DCI 415-a and the PHR timing reference point, the UE 115 may be configured to operate according to one of the above examples. In other cases, the UE 115 may semi-statically or dynamically select which example to operate according to based on one or more parameters (e.g., temporal proximity of previous or subsequent PUSCH resources, information in the first DCI 415-a, etc.).

[0124] These examples may support power headroom calculations for the second cell 405-b (and the second carrier) with or without a granted PUSCH as a calculation reference. In some cases, the second and third examples may be implemented as replacements for PHR timing reference points, where the UE 115 may use one or both of these operations to determine power headroom calculations regardless of the timing of the second DCI 415-b. In other cases, based on one or both of these operations, the PHR timing may be further relaxed (e.g., the amount of time 420 may be extended).

[0125] Figure 5 An example of a power headroom reporting timeline 500 that supports a power headroom reporting procedure for multiple cells in accordance with aspects of the present disclosure is illustrated. The power headroom reporting timeline 500 illustrates UE 115 operations for reporting power headroom measurements for multiple cells 505 (e.g., a first cell 505-a and a second cell 505-b). The UE 115 may be as described with reference to Figures 1 to 4 An example of a UE 115 is described. According to the power headroom reporting timeline 500, the UE 115 may drop resources from one or more PUSCH resource sets 525 to avoid overlapping uplink transmissions. In such a scenario, the UE 115 may manage the power headroom reporting such that the PHR is still transmitted to the base station 105 despite the loss of resources.

[0126] In the power headroom reporting timeline 500, the UE 115 may identify a PHR trigger 510 that may prompt the UE 115 to report power headroom measurements for one or more serving cells 505. Based on the identified PHR trigger 510, the UE 115 may schedule a PHR transmission in an uplink resource (e.g., a PUSCH resource 525). In one example, the UE 115 may receive a DCI 515-a for a first cell 505-a. The DCI 515-a may indicate scheduling of uplink transmissions for the UE 115 in the first PUSCH resources 525-a. The UE 115 may determine to transmit a PHR in these scheduled first PUSCH resources 525-a based on the PHR trigger 510 and the received first DCI 515-a. However, in some cases, the UE 115 may receive a second DCI 515-b for a second cell 505-b. The DCI 515-b may schedule the UE 115 for uplink transmissions in second PUSCH resources 525-b that overlap with the first PUSCH resources 525-a in time, frequency, or both. The UE 115 may not support simultaneous or concurrent transmissions to different cells 505 in the two overlapping PUSCH resource sets 525.

[0127] In some cases, the UE 115 may drop (e.g., intentionally drop) resources from one of the PUSCH resource sets 525 to avoid transmitting partially or completely overlapping signals on the uplink (e.g., if the UE 115 does not support concurrently transmitting at least partially overlapping PUSCH transmissions when these PUSCH transmissions are scheduled on an in-band component carrier). For example, due to the presence of the second PUSCH resource 525-b, the UE 115 may drop the first PUSCH resource 525-a corresponding to the first DCI 515-a. In some examples, the second PUSCH resource 525-b may correspond to an eURLLC PUSCH resource, which may have a relatively higher transmission priority than the first PUSCH resource 525-a (e.g., an eMBB PUSCH resource). If the first PUSCH is dropped, the UE 115 may adaptively switch the PHR transmission to the second PUSCH. The PHR may include calculated power headroom measurements for both the first cell 505-a and the second cell 505-b. The UE 115 may determine the power headroom for the second cell 505-b using an actual power headroom calculation (e.g., based on an actual transmit power for the second PUSCH resource 525-b indicated in the second DCI 515-b). The UE 115 may calculate the power headroom for the first cell 505-a using an actual or virtual calculation.

[0128] In a first example, the UE 115 may determine whether to calculate an actual power headroom for the first cell 505-a (e.g., based on a transmit power indicated in a first DCI 515-a for a first PUSCH resource 525-a) or a virtual power headroom (e.g., based on a preconfigured value or parameter in a second DCI 515-b for a second PUSCH resource 525-b). The UE 115 may make this determination based on the timing or content of the received DCI 515, the scheduled PUSCH resources 525, or both. In some cases, if there is a sufficient time gap 520 between the end of the second PDCCH (e.g., the second DCI 515-b) and the beginning of the second PUSCH 525-b, the UE 115 may calculate the power headroom for the first cell 505-a based on a virtual calculation.

[0129] If the time gap 520 is at least as long as the timing used to perform the virtual power headroom calculation for the first cell 505-a, the UE 115 may recalculate the power headroom for the first cell 505-a using the virtual calculation. In other cases, if the time gap 520 is insufficient to perform the recalculation, the UE 115 may include the power headroom calculated for the first cell 505-a based on the actual grant (e.g., the transmit power in the first DCI 515-a granting the first PUSCH resource 525-a).

[0130] In other situations (e.g., if the first symbol of the second PUSCH resource 525-b precedes the first symbol of the first PUSCH resource 525-a, such that the PHR is sent in the second PUSCH resource 525-b before the actual calculation for the first cell 505-a is completed), the UE 115 may calculate the power headroom for the first cell 505-a using some other type of calculation (e.g., a low-latency virtual calculation based on the processing time of the second cell 505-b). For example, the processing time used by the UE 115 to calculate the power headroom values ​​on different cells 505 may depend on the SCS or may depend on the different timing capabilities of the cells 505.

[0131] In one scenario, the processing time for the eMBB power headroom calculation may be longer than the processing time for the URLLC power headroom calculation. Therefore, the power headroom timing for the first cell 505-a may be different from the power headroom timing for the second cell 50-5b. In some scenarios, the UE 115 may report the timing capabilities for one or more cells 505 to the base station 105.

[0132] In a second example, the UE 115 may calculate an actual power headroom for the first cell 505-a (e.g., regardless of or independent of timing). When the second PUSCH resource 525-b is scheduled, the UE 115 may discard the first PUSCH resource 525-a carrying the first PHR (e.g., based on the priority metric of the second PUSCH resource 525-b being greater than the priority metric of the first PUSCH resource 525-a). The UE 115 may alternatively include power headroom measurements for both the first cell 505-a and the second cell 505-b in the PHR transmitted in the second PUSCH resource 525-b. These power headroom measurements may include two actual power headroom measurements based on the respective transmit powers indicated in the respective DCI 515 transmissions. For example, when the first DCI 515-a is received, the UE 115 may begin calculating the actual power headroom of the first cell 505-a based on the PUSCH transmit power information included in the first DCI 515-a. The UE 115 may use this value in the PHR transmitted in the second PUSCH resource 525 - b rather than performing any recalculation.

[0133] The UE 115 may maintain the PHR trigger 510 to support PUSCH resource discarding without discarding the PHR transmission. For example, when the first DCI 515-a is received and the power headroom calculation is initiated, the UE 115 may maintain the PHR trigger(s) 510 instead of canceling one or more PHR triggers 510. If the PUSCH carrying the PHR is not cancelled or partially discarded (e.g., based on another PUSCH), the UE 115 may cancel the PHR trigger(s) 510. For example, the UE 115 may maintain the PHR trigger(s) 510 until the PHR is actually transmitted in the PUSCH resource 525. Based on satisfying the condition (e.g., based on the PHR transmission), the UE 115 may cancel the PHR trigger(s) 510 (e.g., all PHR triggers). Additionally or alternatively, as opposed to when the DCI 515 is received, the UE 115 may restart the PHR prohibit timer upon transmitting the PHR.

[0134] In some cases, UE 115 may be configured to Figure 3 and 4 In other cases, the UE 115 may be configured to operate according to the reference Figure 5 In some other cases, the UE 115 may operate according to some combination of these processes. For example, the UE 115 may perform some combination of these operations or may select between these operations based on one or more parameters.

[0135] For example, in some systems, if the PUSCH corresponds to the initial transmission of the TB, the PHR may be sent on the PUSCH. This may be based on a bit buffering procedure at the UE 115. For example, for the initial transmission of the TB, the UE 115 may encode a set of payload bits and may load the encoded bits into a buffer (e.g., a HARQ buffer, a circular buffer, etc.). The UE 115 may transmit a selection of bits from the buffer in a codeword as an initial TB transmission. For each retransmission of the TB, the UE 115 may select a different set of bits from the preloaded buffer for transmission. Therefore, the UE may not be able to introduce new information (e.g., PHR) into the TB retransmission without re-encoding the TB with additional bits representing the new information. Therefore, if the initial transmission of the TB does not include the PHR, the UE 115 may not be able to include the PHR in the TB retransmission.

[0136] Thus, if the first PUSCH corresponds to the first transmission of a TB and is not a retransmission, the UE 115 may implement the reference Figure 3 and 4 In this case, the second PUSCH may or may not correspond to a retransmission of a TB. Alternatively, if the second PUSCH corresponds to an initial transmission of a TB, the UE 115 may implement the reference Figure 5 The second operation described. In this case, the first PUSCH may or may not correspond to a retransmission of a TB. In some cases, any one PUSCH resource set does not correspond to an initial TB transmission, or the resources corresponding to the initial TB transmission (e.g., the first PUSCH resource) may be discarded. In these cases, the UE 115 may be able to send a PHR in a later PUSCH resource (e.g., corresponding to a new TB or corresponding to a retransmission of a TB if the initial TB is discarded but includes a PHR). For example, if the UE 115 discards the first PUSCH resource 525-a, and if the second PUSCH resource 525-b corresponds to a retransmission of a TB, the UE 115 may transmit a PHR in the next available PUSCH resource 525 that is not discarded and is associated with the initial transmission of the HARQ process. The type of TB is one way that the UE 115 can determine which power headroom reporting operation to implement based on an adaptive reporting scenario, but other ways of selecting a power headroom reporting operation may be supported.

[0137] Figure 6 An example of a process flow 600 for supporting a power headroom reporting procedure for multiple cells in accordance with aspects of the present disclosure is illustrated. The process flow 600 may include a base station 105-b and a UE 115-b, which may be referenced Figures 1 to 5Examples of corresponding devices described. UE 115-b may use one or more operations to transmit multiple PHRs to base station 105-b for improved accuracy, improved reliability, or both. The following alternative examples may be implemented, where the steps may be performed in an order different from the order described or not performed at all. In some cases, the steps may include additional features not mentioned below, or further steps may be added.

[0138] At 605, UE 115-b may identify a trigger for transmitting a PHR. If UE 115-b identifies a timer, such as a periodic timer (e.g., phr-PeriodicTimer), that has expired, the PHR may be triggered. If UE 115-b identifies a second time, such as a prohibit timer (e.g., phr-ProhibitTimer), that has expired, and if UE 115-b determines that a current path loss for at least one cell differs from a reference path loss for one or more of the same cells by more than a path loss change threshold (e.g., phr-Tx-PowerFactorChange), the PHR may also be triggered. The first and second reference cells used to determine the path loss may be the same cell, or may be different cells. Once UE 115-b identifies a trigger for transmitting the PHR, UE 115-b may maintain the trigger after it has received the first DCI. Once UE 115-b has transmitted the PHR, UE 115-b may cancel or discard the identified trigger. Additionally or alternatively, UE 115-b may reset the PHR prohibit timer upon transmitting the PHR.

[0139] At 610, UE 115-b may receive a first DCI from base station 105-b. The first DCI may indicate a first uplink resource for a first cell and may be received on a first carrier. The first uplink resource may be a PUSCH or other example of an uplink resource. The first DCI may be transmitted by base station 105-b on a first PDCCH or other example of a downlink resource. The first DCI may also indicate a first transmit power for UE 115-b to use for transmissions in the first uplink resource.

[0140] At 615, in some cases, UE 115-b may receive a second DCI from base station 105-b (or a different base station 105). The second DCI may indicate a second uplink resource for a second cell and may be received on a second carrier. The second uplink resource may be a PUSCH or other example of an uplink resource. The second DCI may be transmitted by base station 105-b on a second PDCCH or other example of a downlink resource. In some cases, the second uplink resources may be scheduled so that they overlap in time with the first uplink resources. The second DCI may also indicate a transmit power for UE 115-b to use for transmissions in the second uplink resource.

[0141] At 620, UE 115-b may determine whether it has received a second DCI and may determine the timing of any received second DCI. For example, UE 115-b may determine whether the second DCI is received after the first DCI and before the first uplink resource set scheduled by the first DCI. In some cases, UE 115-b may additionally determine whether the second DCI is received before a PHR reference time. The PHR reference time may be based on a power headroom processing timeline for the first cell, which in turn may be based on a processing capability of UE 115-b, an SCS for the first cell, other information, or any combination thereof. In some examples, UE 115-b may transmit a report to base station 105-b indicating the processing capability of UE 115-b, an SCS for the first cell, other information, or any combination thereof.

[0142] In one scenario, UE 115-b may receive a second DCI after receiving the first DCI and before a PHR reference time. The PHR reference time may be based on a power headroom processing timeline for the first cell and an initial symbol of the first uplink resource. In this scenario, calculation of the second power headroom may be based on a second transmit power indicated by the second DCI. The PHR may include a second power headroom calculated based on the second transmit power and a first power headroom calculated based on the first transmit power.

[0143] In another scenario, UE 115-b may determine that a second DCI is not received after the first DCI and before the power headroom reference time. For example, UE 115-b may receive the second DCI after the PHR reference time. In this scenario, UE 115-b may calculate a second power headroom for the PHR based on determining that a second DCI is not received after the first DCI and before the power headroom reference time. For example, the calculation of the second power headroom may be based on a virtual calculation, which may be based on one or more preconfigured parameters, one or more parameters indicated by the first DCI, other information, or any combination thereof. The calculation of the second power headroom may be additionally or alternatively based on the transmit power of a previous uplink resource for the second cell. The previous uplink resource may have been scheduled before receiving the first DCI. Further, the calculation of the second power headroom may be additionally or alternatively based on the transmit power of a previous non-granted uplink opportunity or a next non-granted uplink opportunity. The previous non-granted uplink opportunity may have been scheduled before receiving the first DCI.

[0144] In another scenario, UE 115-b may receive a second DCI after receiving the first DCI and before the first uplink resource scheduled by the first DCI. The second DCI may indicate a second uplink resource that at least partially overlaps in time with the first uplink resource. UE 115-b may discard at least a portion of resources from the first uplink resource or the second uplink resource based on the overlapping resources. The PHR may be transmitted in the first uplink resource or the second uplink resource based on which resources are discarded (e.g., if the first resource is discarded, the PHR may be transmitted in the second resource, and vice versa).

[0145] In a first example, the first uplink resource may have a first priority value and the second uplink resource may have a second priority value different from the first priority value. UE 115-b may determine whether to discard a portion of the first uplink resource or the second uplink resource depending on the priority value. In one case, if the first uplink resource has a lower priority value than the second uplink resource, UE 115-b may discard a portion of the resources from the first uplink resource. In another case, if the second uplink resource has a lower priority value than the first uplink resource, UE 115-b may discard a portion of the resources from the second uplink resource.

[0146] In a second example, the first uplink resource and the second uplink resource may have the same priority value. In this example, UE 115-b may determine whether to drop resources from the first uplink resource or the second uplink resource based on a preconfiguration.

[0147] At 625, UE 115-b may calculate a first power headroom for a first cell and a second power headroom for a second cell. The PHR may be based on (e.g., including) a power headroom for the first cell and a power headroom for the second cell. In some cases, UE 115-b may calculate the first power headroom based on a first transmit power indicated by a first DCI and may calculate the second power headroom based on a virtual calculation. In other cases, UE 115-b may calculate the first power headroom based on a virtual calculation and calculate the second power headroom based on a second transmit power indicated by a second DCI. In yet other cases, UE 115-b may calculate two power headrooms using the transmit power indicated by the DCI. The virtual calculation may be based on preconfigured parameters, parameters indicated by DCI for different cells, or a combination thereof. In some cases, UE 115-b may calculate the second power headroom based on determining whether the second DCI is received before the PHR reference time.

[0148] At 630, UE 115-b may transmit a PHR to base station 105-b. The transmitted PHR may include a first power clearance for a first cell and a second power clearance for a second cell. In some cases, the first power clearance may correspond to a first processing timeline (e.g., an eMBB timeline) and the second cell may correspond to a second processing timeline (e.g., a URLLC timeline) that is different from (e.g., shorter than) the first processing timeline. The PHR may be transmitted in the initial transmission of the TB. In some cases, the PHR may be transmitted by UE 115-b in a first uplink resource (e.g., based on receiving a DCI indicating these first uplink resources in a first monitoring opportunity). In other cases, UE 115-b may transmit a PHR to base station 105-b in a second uplink resource based on discarding a portion of the resources (e.g., the first uplink resources). In still other cases, both the first uplink resource and the second uplink resource correspond to a retransmission of the TB. In some such situations, UE 115-b may transmit a PHR in a third uplink resource corresponding to an initial transmission of a TB.

[0149] Figure 7 A block diagram 700 of a device 705 supporting a power headroom reporting procedure for multiple cells in accordance with aspects of the present disclosure is shown. The device 705 may be an example of aspects of a UE 115 as described herein. The device 705 may include a receiver 710, a power headroom reporting module 715, and a transmitter 720. The device 705 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0150] 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 power headroom reporting procedures for multiple cells, etc.). The information may be passed to other components of the device 705. The receiver 710 may be a reference Fig.10 Examples of aspects of the described transceiver 1020. The receiver 710 may utilize a single antenna or a collection of antennas.

[0151] The power headroom reporting module 715 may identify a trigger for transmitting a PHR and may receive a first DCI for a first cell indicating a first uplink resource. The power headroom reporting module 715 may further determine whether a second DCI for a second cell indicating a second uplink resource is received after receiving the first DCI and before the first uplink resource. The power headroom reporting module 715 may transmit a PHR including a first power headroom for the first cell and a second power headroom for the second cell, wherein the PHR is based on the determination. The power headroom reporting module 715 may be an example of aspects of the power headroom reporting module 1010 described herein.

[0152] The actions performed by the power headroom reporting module 715 as described herein may be implemented to achieve one or more potential advantages. For example, transmitting a PHR based on whether and when a second DCI is received may allow the UE 115 to provide more accurate power headroom measurements for multiple cells. The UE 115 may account for DCI received for the second cell (e.g., when received after the DCI for the first cell but before the PHR reference time) to perform an actual power headroom calculation, as opposed to a virtual power headroom calculation that may be less accurate. Additionally or alternatively, the UE 115 may reduce latency involved in power headroom reporting when overlapping PUSCH resources are discarded by ensuring that the PHR is sent in the remaining PUSCH resources.

[0153] Based on transmitting the PHR according to whether and when the second DCI is received, a processor of the UE 115 (e.g., a processor controlling the receiver 710, the power headroom reporting module 715, the transmitter 720, etc.) can reduce processing resources for power headroom reporting. For example, by supporting more accurate power headroom measurements, the UE 115 can reduce the number of times power headroom reporting is triggered at the UE 115. Reducing the number of triggered PHR transmissions can reduce the number of times the processor ramps up processing power and turns on processing units to handle power headroom calculations and PHR transmissions.

[0154] The power headroom reporting module 715 or its subcomponents may be implemented in hardware, in 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 power headroom reporting module 715 or its subcomponents may be performed 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.

[0155] The power headroom reporting module 715 or its subcomponents may be physically located at various locations, including being distributed such that portions of the functionality are implemented by one or more physical components at different physical locations. In some examples, the power headroom reporting module 715 or its subcomponents may be separate and distinct components according to aspects of the present disclosure. In some examples, according to aspects of the present disclosure, the power headroom reporting module 715 or its subcomponents may be combined with one or more other hardware components (including, but not limited to, input / output (I / O) components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof).

[0156] The transmitter 720 may transmit signals generated by other components of the device 705. In some examples, the transmitter 720 may be co-located with the receiver 710 in a transceiver module. For example, the transmitter 720 may be a reference Fig.10 Examples of aspects of the described transceiver 1020. The transmitter 720 may utilize a single antenna or a collection of antennas.

[0157] Figure 8 A block diagram 800 of a device 805 supporting a power headroom reporting procedure for multiple cells in accordance with aspects of the present disclosure is shown. The device 805 may be an example of aspects of the device 705 or UE 115 as described herein. The device 805 may include a receiver 810, a power headroom reporting module 815, and a transmitter 840. The device 805 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0158] The receiver 810 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 power headroom reporting procedures for multiple cells, etc.). The information may be passed to other components of the device 805. The receiver 810 may be a reference Fig.10 Examples of aspects of the described transceiver 1020. The receiver 810 may utilize a single antenna or a collection of antennas.

[0159] The power headroom reporting module 815 may be an example of aspects of the power headroom reporting module 715 described herein. The power headroom reporting module 815 may include a triggering component 820, a DCI receiving component 825, a processing determination component 830, and a PHR component 835. The power headroom reporting module 815 may be an example of aspects of the power headroom reporting module 1010 described herein.

[0160] The triggering component 820 may identify a trigger for transmitting a PHR. The DCI receiving component 835 may receive a first DCI for a first cell indicating a first uplink resource. The processing determining component 830 may determine whether a second DCI for a second cell indicating a second uplink resource is received after receiving the first DCI and before the first uplink resource. The PHR component 835 may transmit a PHR including a first power headroom for the first cell and a second power headroom for the second cell, wherein the PHR is based on the determination.

[0161] The transmitter 840 may transmit signals generated by other components of the device 805. In some examples, the transmitter 840 may be co-located with the receiver 810 in a transceiver module. For example, the transmitter 840 may be a reference Fig.10 Examples of various aspects of the transceiver 1020 are described. The transmitter 840 may utilize a single antenna or a collection of antennas.

[0162] Fig. 9 A block diagram 900 of a power headroom reporting module 905 supporting a power headroom reporting procedure for multiple cells in accordance with aspects of the present disclosure is shown. The power headroom reporting module 905 may be an example of aspects of the power headroom reporting module 715, the power headroom reporting module 815, or the power headroom reporting module 1010 described herein. The power headroom reporting module 905 may include a triggering component 910, a DCI receiving component 915, a processing determining component 920, a PHR component 925, a power headroom calculating component 930, a capability reporting component 935, a resource discarding component 940, an initial TB transmission component 945, and a PHR timer component 950. Each of these modules may communicate directly or indirectly with each other (e.g., via one or more buses).

[0163] Trigger component 910 can identify a trigger for transmitting a PHR. In some cases, identifying a trigger for transmitting a PHR involves PHR timer component 950 identifying that a PHR prohibit timer has expired and determining that a current path loss for at least one cell differs from a reference path loss for the at least one cell by more than a path loss change threshold, wherein the reference path loss corresponds to a most recent PHR transmission for the at least one cell. In other cases, identifying a trigger for transmitting a PHR involves PHR timer component 950 identifying that a PHR period timer has expired.

[0164] DCI receiving component 915 can receive a first DCI for a first cell indicating a first uplink resource.In some cases, power headroom calculating component 930 can calculate a first power headroom based on a transmit power indicated by the first DCI, wherein the PHR is based on calculating the first power headroom.

[0165] Processing determination component 920 may determine whether a second DCI indicating a second uplink resource is received for a second cell after receiving the first DCI and before the first uplink resource. In some cases, processing determination component 920 may determine whether the second DCI is received before a PHR reference time based on a power headroom processing timeline for the first cell and an initial symbol of the first uplink resource. In these cases, power headroom calculation component 930 may calculate a second power headroom based on determining whether the second DCI is received before the PHR reference time, wherein the PHR is based on calculating the second power headroom.

[0166] In some examples, DCI receiving component 915 can receive a second DCI after receiving the first DCI and before the PHR reference time. In these examples, power headroom calculating component 930 can calculate a second power headroom based on the transmit power indicated by the second DCI, wherein the PHR is based on calculating the second power headroom.

[0167] In other examples, processing determining component 920 can determine that a second DCI is not received after the first DCI and before the PHR reference time, wherein calculating the second power headroom is based on determining that the second DCI is not received.

[0168] In a first example, the power headroom calculation component 930 may calculate the second power headroom using a virtual calculation based on one or more preconfigured parameters, one or more parameters indicated by the first DCI, or a combination thereof, wherein the PHR is based on calculating the second power headroom. In a second example, the power headroom calculation component 930 may calculate the second power headroom based on a transmit power of a previous uplink resource for the second cell, wherein the previous uplink resource was scheduled before receiving the first DCI, wherein the PHR is based on calculating the second power headroom. In a third example, the power headroom calculation component 930 may calculate the second power headroom based on a transmit power of a previous no-grant uplink opportunity or a next no-grant uplink opportunity for the second cell, wherein the previous no-grant uplink opportunity was scheduled before receiving the first DCI, and the next no-grant uplink opportunity is scheduled after receiving the first DCI, and wherein the PHR is based on calculating the second power headroom.

[0169] In some examples, DCI receiving component 915 may receive a second DCI after a PHR reference time, wherein determining that the second DCI was not received after the first DCI and before the PHR reference time is based on receiving the second DCI after the PHR reference time.

[0170] In some cases, the power headroom processing timeline for the first cell is based on a UE processing capability for the first cell, a subcarrier spacing (SCS) for the first cell, or a combination thereof. Capability reporting component 935 may transmit a report indicating the UE processing capability for the first cell, the SCS for the first cell, or a combination thereof.

[0171] In some examples, the DCI receiving component 915 can receive a second DCI after receiving the first DCI and before the first uplink resource, wherein the first uplink resource overlaps at least partially with the second uplink resource indicated by the second DCI. In some cases, the resource discarding component 940 can discard at least a portion of the resources from the first uplink resource or the second uplink resource based on the partial overlap, wherein the PHR is transmitted in the first uplink resource or the second uplink resource based on the discarding.

[0172] In some examples, the first priority value of the first uplink resource is different from the second priority value of the second uplink resource. In these examples, the resource discarding component 940 can determine whether to discard the portion of resources from the first uplink resource or the second uplink resource based on at least one of the first priority value or the second priority value, wherein if the first priority value is less than the second priority value, the portion of resources is discarded from the first uplink resource, and if the first priority value is greater than the second priority value, the portion of resources is discarded from the second uplink resource. In other examples, the first priority value of the first uplink resource is equal to the second priority value of the second uplink resource. In these examples, the resource discarding component 940 can determine whether to discard the portion of resources from the first uplink resource or the second uplink resource based on preconfiguration, wherein discarding at least the portion of resources from the first uplink resource or the second uplink resource is based on determining whether to discard the portion of resources from the first uplink resource or the second uplink resource.

[0173] In some cases, the PHR is transmitted in the second uplink resource based on the discard. In some of these cases, the power headroom calculation component 930 may calculate the first power headroom based on the transmit power indicated by the first DCI, and may calculate the second power headroom based on the transmit power indicated by the second DCI. In other cases of these cases, the power headroom calculation component 930 may calculate the first power headroom using a virtual calculation, wherein the virtual calculation is based on one or more preconfigured parameters, one or more parameters indicated by the second DCI, or a combination thereof, and the power headroom calculation component 930 may calculate the second power headroom based on the transmit power indicated by the second DCI. The power headroom calculation component 930 may determine whether to recalculate the first power headroom based on the power headroom processing timeline for the first cell and the initial symbol of the second uplink resource.

[0174] The PHR component 925 may transmit a PHR including a first power headroom for a first cell and a second power headroom for a second cell, wherein the PHR is based on determining whether a second DCI indicating a second uplink resource is received for the second cell after receiving the first DCI and before receiving the first uplink resource. In some cases, the first cell corresponds to a first processing timeline (e.g., an eMBB processing timeline) and the second cell corresponds to a second processing timeline (e.g., a URLLC timeline) that is shorter than the first processing timeline.

[0175] In some cases, transmitting the PHR may involve the initial TB transmission component 945 transmitting the PHR in an initial transmission of the TB. In some examples, the initial TB transmission component 945 may determine whether to transmit the PHR in the first uplink resource or the second uplink resource based on whether the first uplink resource or the second uplink resource corresponds to the initial transmission of the TB. In some examples, if the first uplink resource and the second uplink resource correspond to a retransmission of the TB, transmitting the PHR may involve the initial TB transmission component 945 transmitting the PHR in a third uplink resource corresponding to the initial transmission of the TB.

[0176] In some examples, trigger component 910 can maintain the identified trigger upon receiving the first DCI, and cancel the identified trigger based on transmitting the PHR. In some examples, PHR timer component 950 can start a PHR prohibit timer upon canceling the identified trigger.

[0177] Fig.10 A diagram of a system 1000 including a device 1005 supporting a power headroom reporting procedure for multiple cells in accordance with various aspects of the present disclosure is shown. The device 1005 may be an example of or include components of the device 705, device 805, or UE 115 as described herein. The device 1005 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a power headroom reporting manager 1010, an I / O controller 1015, a transceiver 1020, an antenna 1025, a memory 1030, and a processor 1040. These components may be in electronic communication via one or more buses (e.g., bus 1045).

[0178] The power headroom reporting module 1010 can identify a trigger for transmitting a PHR; receive a first DCI indicating a first uplink resource for a first cell; determine whether a second DCI indicating a second uplink resource for a second cell is received after receiving the first DCI and before the first uplink resource; and transmit a PHR including a first power headroom for the first cell and a second power headroom for the second cell, wherein the PHR is based on the determination.

[0179] I / O controller 1015 can manage input and output signals of device 1005. I / O controller 1015 can also manage peripheral devices that are not integrated into device 1005. In some cases, I / O controller 1015 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 1015 can utilize an operating system, such as Or another known operating system. In other cases, I / O controller 1015 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I / O controller 1015 may be implemented as part of a processor. In some cases, a user may interact with device 1005 via I / O controller 1015 or via hardware components controlled by I / O controller 1015.

[0180] The transceiver 1020 can communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 1020 may represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 1020 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0181] In some cases, a wireless device may include a single antenna 1025. However, in some cases, the device may have more than one antenna 1025, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0182] Memory 1030 may include random access memory (RAM) and read-only memory (ROM). Memory 1030 may store computer-readable, computer-executable code 1035 including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, memory 1030 may include, among other things, a basic I / O system (BIOS) that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0183] The processor 1040 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a central processing unit (CPU), a microcontroller, an ASIC, an FPGA, a programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, the processor 1040 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into the processor 1040. The processor 1040 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1030) to cause the device 1005 to perform various functions (e.g., functions or tasks that support a power headroom reporting procedure for multiple cellular cells).

[0184] The code 1035 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 1035 may be stored in a non-transitory computer-readable medium, such as a system memory or other type of memory. In some cases, the code 1035 may not be directly executable by the processor 1040, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0185] Fig.11 1 is a flow chart of a method 1100 for supporting a power headroom reporting procedure for multiple cells in accordance with aspects of the present disclosure. The operations of the method 1100 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 1100 may be implemented by a UE 115 or components thereof as described herein. Figures 7 to 10 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0186] At 1105, the UE may identify a trigger for transmitting a PHR. The operations of 1105 may be performed according to the methods described herein. In some examples, aspects of the operations of 1105 may be performed as described with reference to Figures 7 to 10 The described trigger component is executed.

[0187] At 1110, the UE may receive a first DCI indicating a first uplink resource for a first cellular cell. The operations of 1110 may be performed according to the methods described herein. In some examples, aspects of the operations of 1110 may be performed as described with reference to Figures 7 to 10 The DCI receiving component described is performed.

[0188] At 1115, the UE may determine whether a second DCI indicating a second uplink resource for a second cell is received after receiving the first DCI and before receiving the first uplink resource. The operations of 1115 may be performed according to the methods described herein. In some examples, aspects of the operations of 1115 may be performed as described with reference to Figures 7 to 10 The described processes determine the components to perform.

[0189] At 1120, the UE may transmit a PHR including a first power headroom for the first cell and a second power headroom for the second cell, wherein the PHR is based on the determination. The operations of 1120 may be performed according to the methods described herein. In some examples, aspects of the operations of 1120 may be performed as described with reference to Figures 7 to 10 The described PHR components are performed.

[0190] Fig.121 is a flow chart of a method 1200 for supporting a power headroom reporting procedure for multiple cells in accordance with aspects of the present disclosure. The operations of the method 1200 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 1200 may be implemented by a UE 115 or components thereof as described herein. Figures 7 to 10 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0191] At 1205, the UE may identify a trigger for transmitting a PHR. The operations of 1205 may be performed according to the methods described herein. In some examples, aspects of the operations of 1205 may be performed as described with reference to Figures 7 to 10 The described trigger component is executed.

[0192] At 1210, the UE may receive a first DCI indicating a first uplink resource for a first cellular cell. The operations of 1210 may be performed according to the methods described herein. In some examples, aspects of the operations of 1210 may be performed as described with reference to Figures 7 to 10 The DCI receiving component described is performed.

[0193] At 1215, the UE may calculate a first power headroom based on the transmit power indicated by the first DCI, wherein the PHR is based on calculating the first power headroom. The operations of 1215 may be performed according to the methods described herein. In some examples, aspects of the operations of 1215 may be as described with reference to Figures 7 to 10 The power headroom calculation components described are performed.

[0194] At 1220, the UE may determine whether a second DCI indicating a second uplink resource is received for the second cell after receiving the first DCI and before the first uplink resource. For example, the UE may determine whether the second DCI is received before a PHR reference time based on a power headroom processing timeline for the first cell and an initial symbol of the first uplink resource. The operations of 1220 may be performed according to the methods described herein. In some examples, aspects of the operations of 1220 may be performed as described with reference to Figures 7 to 10 The described processes determine the components to perform.

[0195] At 1225, the UE may calculate a second power headroom based on determining whether a second DCI is received before a PHR reference time, wherein the PHR is based on calculating the second power headroom. The operations of 1225 may be performed according to the methods described herein. In some examples, aspects of the operations of 1225 may be performed as described with reference to Figures 7 to 10 The power headroom calculation components described are performed.

[0196] At 1230, the UE may transmit a PHR including a first power headroom for the first cell and a second power headroom for the second cell, wherein the PHR is based on the determination. The operations of 1230 may be performed according to the methods described herein. In some examples, aspects of the operations of 1230 may be performed as described with reference to Figures 7 to 10 The described PHR components are performed.

[0197] Fig.13 1 is a flow chart of a method 1300 for supporting a power headroom reporting procedure for multiple cells in accordance with aspects of the present disclosure. The operations of the method 1300 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 1300 may be implemented by a UE 115 or components thereof as described herein. Figures 7 to 10 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0198] At 1305, the UE may identify a trigger for transmitting a PHR. The operations of 1305 may be performed according to the methods described herein. In some examples, aspects of the operations of 1305 may be performed as described with reference to Figures 7 to 10 The described trigger component is executed.

[0199] At 1310, the UE may receive a first DCI indicating a first uplink resource for a first cellular cell. The operations of 1310 may be performed according to the methods described herein. In some examples, aspects of the operations of 1310 may be performed as described with reference to Figures 7 to 10 The DCI receiving component described is performed.

[0200] At 1315, the UE may receive a second DCI after receiving the first DCI and before the first uplink resource, wherein the first uplink resource at least partially overlaps with the second uplink resource indicated by the second DCI. In some cases, the UE may determine that the second DCI is received after receiving the first DCI and before the first uplink resource. The operations of 1315 may be performed according to the methods described herein. In some examples, aspects of the operations of 1315 may be performed as described with reference to Figures 7 to 10 The DCI receiving component described is performed.

[0201] At 1320, the UE may drop at least a portion of resources from the first uplink resource or the second uplink resource based on the partial overlap, wherein the PHR is transmitted in the first uplink resource or the second uplink resource based on the dropping. The operations of 1320 may be performed according to the methods described herein. In some examples, aspects of the operations of 1320 may be performed as described with reference to Figures 7 to 10 The resource discard component described is executed.

[0202] At 1325, the UE may transmit a PHR including a first power headroom for the first cell and a second power headroom for the second cell, wherein the PHR is based on the determination. The operations of 1325 may be performed according to the methods described herein. In some examples, aspects of the operations of 1325 may be performed as described with reference to Figures 7 to 10 The described PHR components are performed.

[0203] Fig.14 1400 for supporting a power headroom reporting procedure for multiple cells in accordance with aspects of the present disclosure. The operations of the method 1400 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 1400 may be implemented by a UE 115 or components thereof as described herein. Figures 7 to 10 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0204] At 1405, the UE may identify a trigger for transmitting a PHR. 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 as described with reference to Figures 7 to 10 The described trigger component is executed.

[0205] At 1410, the UE may receive a first DCI indicating a first uplink resource for a first cellular cell. 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 as described with reference to Figures 7 to 10 The DCI receiving component described is performed.

[0206] At 1415, the UE may determine whether a second DCI indicating a second uplink resource for a second cell is received after receiving the first DCI and before receiving the first uplink resource. 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 as described with reference to Figures 7 to 10 The described processes determine the components to perform.

[0207] At 1420, the UE may determine whether to transmit the PHR in the first uplink resource or the second uplink resource based on whether the first uplink resource or the second uplink resource corresponds to the initial transmission of the TB. The operations of 1420 may be performed according to the methods described herein. In some examples, aspects of the operations of 1420 may be performed as described with reference to Figures 7 to 10 The initial TB transfer component described is performed.

[0208] At 1425, the UE may transmit a PHR including a first power headroom for the first cell and a second power headroom for the second cell, wherein the PHR is based on the determination and is transmitted in an initial transmission of the TB. The operations of 1425 may be performed according to the methods described herein. In some examples, aspects of the operations of 1425 may be performed as described with reference to Figures 7 to 10 The described PHR components are performed.

[0209] It should be noted that the methods described herein describe possible implementations, and that the various operations and steps may be rearranged or otherwise modified and other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0210] The technology described herein can be used in various wireless communication systems, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA) and other systems. CDMA systems can implement radio technologies such as CDMA2000, Universal Terrestrial Radio Access (UTRA). CDMA2000 covers IS-2000, IS-95 and IS-856 standards. IS-2000 versions are generally referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is generally referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD), etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. TDMA systems can implement radio technologies such as Global System for Mobile Communications (GSM).

[0211] OFDMA systems can implement radio technologies such as Ultra Mobile Broadband (UMB), E-UTRA, Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS). LTE, LTE-A, and LTE-A Pro are versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, LTE-A Pro, NR, and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). CDMA2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). The techniques described herein can be used for the systems and radio technologies mentioned herein as well as for other systems and radio technologies. Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein may also be applicable to applications other than LTE, LTE-A, LTE-A Pro, or NR applications.

[0212] A macro cell generally covers a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access by UEs with service subscriptions to a network provider. A small cell may be associated with a lower power base station (compared to a macro cell), and the small cell may operate in the same or different (e.g., licensed, unlicensed, etc.) frequency band as the macro cell. According to various examples, a small cell may include a pico cell, a femto cell, and a micro cell. A pico cell, for example, may cover a smaller geographic area and may allow unrestricted access by UEs with service subscriptions to a network provider. A femto cell may also cover a smaller geographic area (e.g., a residence) and may provide restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs of users in the residence, etc.). An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB may support one or more (eg, two, three, four, etc.) cells and may also support communication using one or more component carriers.

[0213] The wireless communication systems described herein may support synchronous or asynchronous operation. For synchronous operation, each base station may have similar frame timing, and transmissions from different base stations may be roughly aligned in time. For asynchronous operation, each base station may have different frame timing, and transmissions from different base stations may not be aligned in time. The techniques described herein may be used for synchronous or asynchronous operation.

[0214] The information and signals described herein may be represented using any of a variety of different techniques and technologies. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout this description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0215] The various illustrative blocks and modules described in conjunction with the disclosure herein may be implemented or executed with a general purpose processor, a DSP, an ASIC, 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 an alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0216] 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 by a computer-readable medium as one or more instructions or codes. Other examples and implementations fall within the scope of the present disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. Features that implement the functions may also be physically located in various locations, including being distributed so that parts of the functions are implemented at different physical locations.

[0217] Computer-readable medium includes both non-transient computer storage medium and communication medium, and it includes any medium that facilitates computer program to transfer from one place to another.Non-transient storage medium can be any available medium that can be accessed by general or special-purpose computer.As an example and not limitation, non-transient computer-readable medium can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, disk storage or other magnetic storage device, or can be used to carry or store instruction or data structure form of desired program code means and can be accessed by general or special-purpose computer or general or special-purpose processor any other non-transient medium.Any connection is also properly referred to as computer-readable medium.For example, if software is transmitted from website, server or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL or wireless technology such as infrared, radio and microwave are just included in the definition of medium. Disk and disc as used herein include CDs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, 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.

[0218] As used herein (including in the claims), "or" used in a list of items (e.g., a list of items with a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so 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). Similarly, as used herein, the phrase "based on" should not be interpreted as referring to a closed set of conditions. For example, an exemplary step described as "based on condition A" may be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0219] In the accompanying drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number that distinguishes between similar components. If only the first reference number is used in the specification, the description may apply to any of the similar components having the same first reference number regardless of the second reference number, or other subsequent reference numbers.

[0220] The descriptions set forth herein in conjunction with the accompanying drawings describe example configurations and do not represent all examples that may be implemented or that fall within the scope of the claims. The term "exemplary" as used herein means "used as an example, instance, or illustration" and does not mean "better than" or "better than other examples." This detailed description includes specific details to provide an understanding of the described techniques. However, these techniques may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0221] The description herein is provided to enable those skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled in the art, and the universal principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication by a user equipment (UE), comprising: Identifies a trigger for transmitting a power headroom report; receiving first downlink control information indicating first uplink resources for a first cell; determining whether second downlink control information indicating a second uplink resource for a second cell is received after receiving the first downlink control information and before a power headroom reporting reference time a threshold amount of time before indicating the first uplink resource, wherein the power headroom reporting reference time is based at least in part on a processing capability of the UE and a first symbol of the first uplink resource; as well as The power headroom report is transmitted including a first power headroom for the first cell and a second power headroom for the second cell, wherein the power headroom report is based at least in part on the determination.

2. The method of claim 1, further comprising: The first power headroom is calculated based at least in part on a transmit power indicated by the first downlink control information, wherein the power headroom report is based at least in part on calculating the first power headroom.

3. The method of claim 1 , wherein the power headroom reporting reference time is based at least in part on a power headroom processing timeline for the first cell and an initial symbol of the first uplink resource, the method further comprising: The second power headroom is calculated based at least in part on determining whether the second downlink control information is received before the power headroom reporting reference time, wherein the power headroom reporting is based at least in part on calculating the second power headroom.

4. The method of claim 3, further comprising: receiving the second downlink control information after receiving the first downlink control information and before the power headroom report reference time; as well as The second power headroom is calculated based at least in part on a transmit power indicated by the second downlink control information, wherein the power headroom report is based at least in part on calculating the second power headroom.

5. The method of claim 3, further comprising: A determination is made that the second downlink control information is not received after the first downlink control information and before the power headroom reporting reference time, wherein calculating the second power headroom is based at least in part on the determination that the second downlink control information is not received.

6. The method of claim 5, further comprising: The second power headroom is calculated using a virtual calculation based at least in part on one or more preconfigured parameters, one or more parameters indicated by the first downlink control information, or a combination thereof, wherein the power headroom report is based at least in part on calculating the second power headroom.

7. The method of claim 5, further comprising: The second power headroom is calculated based at least in part on a transmit power of a previous uplink resource for a second cell, wherein the previous uplink resource was scheduled prior to receiving the first downlink control information, and wherein the power headroom report is based at least in part on calculating the second power headroom.

8. The method of claim 5, further comprising: The second power headroom is calculated at least in part based on a transmit power of a previous no-grant uplink opportunity or a next no-grant uplink opportunity for a second cellular cell, wherein the previous no-grant uplink opportunity is scheduled before receiving the first downlink control information and the next no-grant uplink opportunity is scheduled after receiving the first downlink control information, and wherein the power headroom report is based at least in part on calculating the second power headroom.

9. The method of claim 5, further comprising: The second downlink control information is received after the power headroom reporting reference time, wherein determining that the second downlink control information is not received after the first downlink control information and before the power headroom reporting reference time is at least partially based on receiving the second downlink control information after the power headroom reporting reference time.

10. The method of claim 3, wherein the power headroom processing timeline for the first cell is based at least in part on a UE processing capability for the first cell, a subcarrier spacing (SCS) for the first cell, or a combination thereof.

11. The method of claim 10, further comprising: A report is transmitted indicating the UE processing capabilities for the first cell, the SCS for the first cell, or a combination thereof.

12. The method of claim 1, further comprising: receiving the second downlink control information after receiving the first downlink control information and before the first uplink resource, wherein the first uplink resource at least partially overlaps with the second uplink resource indicated by the second downlink control information, and At least a portion of resources is dropped from the first uplink resources or the second uplink resources based at least in part on the partial overlap, wherein the power headroom report is transmitted in the first uplink resources or the second uplink resources based at least in part on the dropping.

13. The method of claim 12, wherein the first priority value of the first uplink resource is different from the second priority value of the second uplink resource, the method further comprising: A determination is made at least in part based on at least one of the first priority value or the second priority value as to whether to discard the portion of resources from the first uplink resource or from the second uplink resource, wherein if the first priority value is less than the second priority value, the portion of resources is discarded from the first uplink resource, and if the first priority value is greater than the second priority value, the portion of resources is discarded from the second uplink resource.

14. The method of claim 12, wherein the first priority value of the first uplink resource is equal to the second priority value of the second uplink resource, the method further comprising: A determination is made at least in part based on a preconfiguration to discard the portion of resources from the first uplink resource or from the second uplink resource, wherein discarding at least the portion of resources from the first uplink resource or from the second uplink resource is at least in part based on a determination to discard the portion of resources from the first uplink resource or from the second uplink resource.

15. The method of claim 12, wherein transmitting the power headroom report in the second uplink resource is based at least in part on the discarding, the method further comprising: calculating the first power headroom based at least in part on a transmit power indicated by the first downlink control information; as well as The second power headroom is calculated based at least in part on a transmit power indicated by the second downlink control information.

16. The method of claim 12, wherein transmitting the power headroom report in the second uplink resource is based at least in part on the discarding, the method further comprising: calculating the first power headroom using a virtual calculation, wherein the virtual calculation is based at least in part on one or more preconfigured parameters, one or more parameters indicated by the second downlink control information, or a combination thereof; as well as The second power headroom is calculated based at least in part on a transmit power indicated by the second downlink control information.

17. The method of claim 12, wherein transmitting the power headroom report in the second uplink resource is based at least in part on the discarding, the method further comprising: A determination is made whether to recalculate the first power headroom based at least in part on a power headroom processing timeline for the first cell and an initial symbol of the second uplink resource.

18. The method of claim 1, wherein transmitting the power headroom report comprises: The power headroom report is transmitted in an initial transmission of a transport block.

19. The method of claim 18, further comprising: Whether to transmit the power headroom report in the first uplink resource or the second uplink resource is determined based at least in part on whether the first uplink resource or the second uplink resource corresponds to an initial transmission of the transport block.

20. The method of claim 18, wherein the first uplink resource and the second uplink resource correspond to a retransmission of a transport block, and wherein transmitting the power headroom report comprises: The power headroom report is transmitted in a third uplink resource corresponding to an initial transmission of the transport block.

21. The method of claim 1, wherein identifying the trigger for transmitting the power headroom report comprises: Indicates that the power headroom report prohibition timer has expired; as well as A determination is made that a current path loss for at least one cell differs from a reference path loss for the at least one cell by more than a path loss change threshold, wherein the reference path loss corresponds to a most recent power headroom report transmission for the at least one cell.

22. The method of claim 1, wherein identifying the trigger for transmitting the power headroom report comprises: Indicates that the power headroom report periodicity timer has expired.

23. The method of claim 1, further comprising: maintaining the identified trigger upon receiving the first downlink control information; as well as The identified trigger is cancelled based at least in part on transmitting the power headroom report.

24. The method of claim 23, further comprising: A power headroom reporting inhibit timer is started upon removal of the identified trigger.

25. The method of claim 1, wherein the first cell corresponds to a first processing timeline and the second cell corresponds to a second processing timeline that is shorter than the first processing timeline.

26. An apparatus for wireless communication by a user equipment (UE), comprising: processor; a memory in electronic communication with the processor; as well as instructions stored in the memory and executable by the processor to cause the apparatus to: Identifies a trigger for transmitting a power headroom report; receiving first downlink control information indicating first uplink resources for a first cell; determining whether second downlink control information indicating a second uplink resource for a second cell is received after receiving the first downlink control information and before a power headroom reporting reference time a threshold amount of time before indicating the first uplink resource, wherein the power headroom reporting reference time is based at least in part on a processing capability of the UE and a first symbol of the first uplink resource; as well as The power headroom report is transmitted including a first power headroom for the first cell and a second power headroom for the second cell, wherein the power headroom report is based at least in part on the determination.

27. The apparatus of claim 26, wherein the instructions are further executable by the processor to cause the apparatus to: The first power headroom is calculated based at least in part on a transmit power indicated by the first downlink control information, wherein the power headroom report is based at least in part on calculating the first power headroom.

28. The apparatus of claim 26, wherein the power headroom reporting reference time is based at least in part on a power headroom processing timeline for the first cell and an initial symbol of the first uplink resource, wherein the instructions are further executable by the processor to cause the apparatus to: The second power headroom is calculated based at least in part on determining whether the second downlink control information is received before the power headroom reporting reference time, wherein the power headroom reporting is based at least in part on calculating the second power headroom.

29. The apparatus of claim 28, wherein the instructions are further executable by the processor to cause the apparatus to: receiving the second downlink control information after receiving the first downlink control information and before the power headroom report reference time; and The second power headroom is calculated based at least in part on a transmit power indicated by the second downlink control information, wherein the power headroom report is based at least in part on calculating the second power headroom.

30. The apparatus of claim 28, wherein the instructions are further executable by the processor to cause the apparatus to: A determination is made that the second downlink control information is not received after the first downlink control information and before the power headroom reporting reference time, wherein calculating the second power headroom is based at least in part on the determination that the second downlink control information is not received.

31. The apparatus of claim 30, wherein the instructions are further executable by the processor to cause the apparatus to: The second power headroom is calculated using a virtual calculation based at least in part on one or more preconfigured parameters, one or more parameters indicated by the first downlink control information, or a combination thereof, wherein the power headroom report is based at least in part on calculating the second power headroom.

32. The apparatus of claim 30, wherein the instructions are further executable by the processor to cause the apparatus to: The second power headroom is calculated based at least in part on a transmit power of a previous uplink resource for a second cell, wherein the previous uplink resource was scheduled prior to receiving the first downlink control information, and wherein the power headroom report is based at least in part on calculating the second power headroom.

33. The apparatus of claim 30, wherein the instructions are further executable by the processor to cause the apparatus to: The second power headroom is calculated at least in part based on a transmit power of a previous no-grant uplink opportunity or a next no-grant uplink opportunity for a second cellular cell, wherein the previous no-grant uplink opportunity is scheduled before receiving the first downlink control information and the next no-grant uplink opportunity is scheduled after receiving the first downlink control information, and wherein the power headroom report is based at least in part on calculating the second power headroom.

34. The apparatus of claim 30, wherein the instructions are further executable by the processor to cause the apparatus to: The second downlink control information is received after the power headroom reporting reference time, wherein determining that the second downlink control information is not received after the first downlink control information and before the power headroom reporting reference time is at least partially based on receiving the second downlink control information after the power headroom reporting reference time.

35. The apparatus of claim 28, wherein the power headroom processing timeline for the first cell is based at least in part on a UE processing capability for the first cell, a subcarrier spacing (SCS) for the first cell, or a combination thereof.

36. The apparatus of claim 35, wherein the instructions are further executable by the processor to cause the apparatus to: A report is transmitted indicating the UE processing capabilities for the first cell, the SCS for the first cell, or a combination thereof.

37. The apparatus of claim 26, wherein the instructions are further executable by the processor to cause the apparatus to: receiving the second downlink control information after receiving the first downlink control information and before the first uplink resource, wherein the first uplink resource at least partially overlaps with the second uplink resource indicated by the second downlink control information, and At least a portion of resources is dropped from the first uplink resources or the second uplink resources based at least in part on the partial overlap, wherein the power headroom report is transmitted in the first uplink resources or the second uplink resources based at least in part on the dropping.

38. The apparatus of claim 37, wherein the first priority value of the first uplink resource is different from the second priority value of the second uplink resource, wherein the instructions are further executable by the processor to cause the apparatus to: A determination is made at least in part based on at least one of the first priority value or the second priority value as to whether to discard the portion of resources from the first uplink resource or from the second uplink resource, wherein if the first priority value is less than the second priority value, the portion of resources is discarded from the first uplink resource, and if the first priority value is greater than the second priority value, the portion of resources is discarded from the second uplink resource.

39. The apparatus of claim 37, wherein the first priority value of the first uplink resource is equal to the second priority value of the second uplink resource, wherein the instructions are further executable by the processor to cause the apparatus to: A determination is made at least in part based on a preconfiguration to discard the portion of resources from the first uplink resource or from the second uplink resource, wherein discarding at least the portion of resources from the first uplink resource or from the second uplink resource is at least in part based on a determination to discard the portion of resources from the first uplink resource or from the second uplink resource.

40. The apparatus of claim 37, wherein the power headroom report is transmitted in the second uplink resource based at least in part on the discarding, wherein the instructions are further executable by the processor to cause the apparatus to: calculating the first power headroom based at least in part on a transmit power indicated by the first downlink control information; and The second power headroom is calculated based at least in part on a transmit power indicated by the second downlink control information.

41. The apparatus of claim 37, wherein the power headroom report is transmitted in the second uplink resource based at least in part on the discarding, wherein the instructions are further executable by the processor to cause the apparatus to: calculating the first power headroom using a virtual calculation, wherein the virtual calculation is based at least in part on one or more preconfigured parameters, one or more parameters indicated by the second downlink control information, or a combination thereof; and The second power headroom is calculated based at least in part on a transmit power indicated by the second downlink control information.

42. The apparatus of claim 37, wherein the power headroom report is transmitted in the second uplink resource based at least in part on the discarding, wherein the instructions are further executable by the processor to cause the apparatus to: A determination is made whether to recalculate the first power headroom based at least in part on a power headroom processing timeline for the first cell and an initial symbol of the second uplink resource.

43. The apparatus of claim 26, wherein the instructions for transmitting the power headroom report are further executable by the processor to cause the apparatus to: The power headroom report is transmitted in an initial transmission of a transport block.

44. The apparatus of claim 43, wherein the instructions are further executable by the processor to cause the apparatus to: Whether to transmit the power headroom report in the first uplink resource or the second uplink resource is determined based at least in part on whether the first uplink resource or the second uplink resource corresponds to an initial transmission of the transport block.

45. The apparatus of claim 43, wherein the first uplink resource and the second uplink resource correspond to a retransmission of a transport block, and wherein the instructions for transmitting the power headroom report are further executable by the processor to cause the apparatus to: The power headroom report is transmitted in a third uplink resource corresponding to an initial transmission of the transport block.

46. ​​The apparatus of claim 26, wherein the instructions for identifying the trigger for transmitting the power headroom report are further executable by the processor to cause the apparatus to: indicating that a power headroom report prohibit timer has expired; and A determination is made that a current path loss for at least one cell differs from a reference path loss for the at least one cell by more than a path loss change threshold, wherein the reference path loss corresponds to a most recent power headroom report transmission for the at least one cell.

47. The apparatus of claim 26, wherein the instructions for identifying the trigger for transmitting the power headroom report are further executable by the processor to cause the apparatus to: Indicates that the power headroom report periodicity timer has expired.

48. The apparatus of claim 26, wherein the instructions are further executable by the processor to cause the apparatus to: maintaining the identified trigger upon receiving the first downlink control information; and The identified trigger is cancelled based at least in part on transmitting the power headroom report.

49. The apparatus of claim 48, wherein the instructions are further executable by the processor to cause the apparatus to: A power headroom reporting inhibit timer is started upon removal of the identified trigger.

50. The apparatus of claim 26, wherein the first cell corresponds to a first processing timeline and the second cell corresponds to a second processing timeline that is shorter than the first processing timeline.

51. An apparatus for wireless communication by a user equipment (UE), comprising: means for identifying a trigger for transmitting a power headroom report; means for receiving first downlink control information indicating first uplink resources for a first cell; means for determining whether second downlink control information indicating a second uplink resource for a second cell is received after receiving the first downlink control information and before a power headroom reporting reference time indicating the first uplink resource a threshold amount of time before the power headroom reporting reference time is based at least in part on a processing capability of the UE and a first symbol of the first uplink resource; as well as Means for transmitting the power headroom report comprising a first power headroom for the first cell and a second power headroom for the second cell, wherein the power headroom report is based at least in part on the determination.

52. A non-transitory computer-readable medium storing code for wireless communication by a user equipment (UE), the code comprising instructions executable by a processor to: Identifies a trigger for transmitting a power headroom report; receiving first downlink control information indicating first uplink resources for a first cell; determining whether second downlink control information indicating a second uplink resource for a second cell is received after receiving the first downlink control information and before a power headroom reporting reference time a threshold amount of time before indicating the first uplink resource, wherein the power headroom reporting reference time is based at least in part on a processing capability of the UE and a first symbol of the first uplink resource; as well as The power headroom report is transmitted including a first power headroom for the first cell and a second power headroom for the second cell, wherein the power headroom report is based at least in part on the determination.

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