Patent Publication Number: US-2023164719-A1

Title: Timing advance indication for multi-panel uplink transmission

Description:
CROSS REFERENCE 
     The present Application is a 371 national stage filing of International PCT Application No. PCT/CN2020/093453 by Yuan et al. entitled “TIMING ADVANCE INDICATION FOR MULTI-PANEL UPLINK TRANSMISSION,” filed May 29, 2020, which is assigned to the assignee hereof, and which is expressly incorporated by reference in its entirety herein. 
    
    
     FIELD OF TECHNOLOGY 
     The following relates generally to wireless communications and more specifically to timing advance indication for multi-panel uplink transmission. 
     BACKGROUND 
     Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE). 
     In some wireless communications systems, a UE may communicate with multiple transmission and reception points (TRPs). In order to support successful communications between multiple TRPs, the UE may receive additional signaling for each of the multiple TRPs. Such additional signaling may result in increased overhead and lower spectral efficiency. 
     SUMMARY 
     In some systems, a user equipment (UE) may support multi-panel communication with a base station and may communicate with the base station via multiple transmission and reception points (TRPs). In some cases, the UE may include multiple panels for communication to the base station, for example each panel communicating with a different TRP associated with the base station. In some cases, the UE may receive a timing advance value for each of the multiple TRPs, which may result in increased overhead and lower spectral efficiency. In the present disclosure, the described techniques relate to improved methods, systems, devices, and apparatuses that support a timing advance indication for multi-panel uplink transmission. Generally, the described techniques provide for receiving, at the UE, a single timing advance value and determining timing advance values for the multiple panels of the UE based on the single timing advance value and a timing of downlink signals received at the multiple panels of the UE. The UE may communicate with the base station via the multiple TRPs accordingly. In some examples, the received timing advance value may be a timing advance value for a reference panel of the UE and the UE may determine timing advance values for each of the remaining panels relative to the timing advance value for the reference panel. In some other implementations, the received timing advance value may be an average (e.g., a mean) of the timing advance value for the multiple panels of the UE and the UE may determine the timing advance value for each of the multiple panels relative to the average timing advance value. 
     A method of wireless communications at a UE is described. The method may include receiving, from a base station, a timing advance value for a serving cell configured for multi-panel communications, determining a first timing advance value for a first panel and a second timing advance value for a second panel based on the received timing advance value and a timing of at least one of a first downlink signal received via the first panel or a second downlink signal received via the second panel, and communicating with one or more TRPs associated with the base station based on the first timing advance value for the first panel and the second timing advance value for the second panel. 
     An apparatus for wireless communications at a UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, from a base station, a timing advance value for a serving cell configured for multi-panel communications, determine a first timing advance value for a first panel and a second timing advance value for a second panel based on the received timing advance value and a timing of at least one of a first downlink signal received via the first panel or a second downlink signal received via the second panel, and communicate with one or more TRPs associated with the base station based on the first timing advance value for the first panel and the second timing advance value for the second panel. 
     Another apparatus for wireless communications at a UE is described. The apparatus may include means for receiving, from a base station, a timing advance value for a serving cell configured for multi-panel communications, determining a first timing advance value for a first panel and a second timing advance value for a second panel based on the received timing advance value and a timing of at least one of a first downlink signal received via the first panel or a second downlink signal received via the second panel, and communicating with one or more TRPs associated with the base station based on the first timing advance value for the first panel and the second timing advance value for the second panel. 
     A non-transitory computer-readable medium storing code for wireless communications at a UE is described. The code may include instructions executable by a processor to receive, from a base station, a timing advance value for a serving cell configured for multi-panel communications, determine a first timing advance value for a first panel and a second timing advance value for a second panel based on the received timing advance value and a timing of at least one of a first downlink signal received via the first panel or a second downlink signal received via the second panel, and communicate with one or more TRPs associated with the base station based on the first timing advance value for the first panel and the second timing advance value for the second panel. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the first panel may be a reference panel, where applying the timing advance value to the first panel may be based on determining that the first panel may be the reference panel. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, from the base station, an indication that the first panel may be the reference panel. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the indication is received via at least one of radio resource control (RRC) signaling, a medium access control (MAC) control element (CE), or downlink control information (DCI). 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first panel is associated with a first panel identifier (ID) lower than a second panel ID associated with the second panel, where determining that the first panel is the reference panel is based on the first panel ID being lower than the second panel ID. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving the first downlink signal via the first panel after receiving the second downlink signal via the second panel, where determining that the first panel may be the reference panel may be based on receiving the first downlink signal via the first panel after receiving the second downlink signal via the second panel. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving the first downlink signal via the first panel prior to receiving the second downlink signal via the second panel, where determining that the first panel may be the reference panel may be based on receiving the first downlink signal via the first panel prior to receiving the second downlink signal via the second panel. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining the second timing advance value for the second panel may include operations, features, means, or instructions for determining an offset based on a difference between when the first downlink signal may be received by the first panel and when the second downlink signal may be received by the second panel, and determining the second timing advance value for the second panel based on the received timing advance value and the offset. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining the first timing advance value for the first panel and the second timing advance value for the second panel may include operations, features, means, or instructions for determining a first offset and a second offset based on a difference between when the first downlink signal may be received by the first panel and when the second downlink signal may be received by the second panel, determining the first timing advance value for the first panel based on the received timing advance value and the first offset, and determining the second timing advance value for the second panel based on the received timing advance value and the second offset. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining the first offset and the second offset may include operations, features, means, or instructions for determining the first offset based on a first difference between when the first downlink signal may be received by the first panel and when the second downlink signal may be received by the second panel, and determining the second offset based on a second difference between when the first downlink signal may be received by the first panel and when the second downlink signal may be received by the second panel. 
     A method of wireless communications at a base station is described. The method may include receiving, from a UE, one or more transmissions from at least one of multiple panels of the UE, determining a timing advance value for a serving cell configured for multi-panel communications based at least in part the received one or more transmissions and a reference timing configuration for the serving cell for the UE, transmitting, to the UE, the timing advance value, and communicating with the UE via one or more TRPs associated with the base station. 
     An apparatus for wireless communications at a base station is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, from a UE, one or more transmissions from at least one of multiple panels of the UE, determine a timing advance value for a serving cell configured for multi-panel communications based at least in part the received one or more transmissions and a reference timing configuration for the serving cell for the UE, transmit, to the UE, the timing advance value, and communicate with the UE via one or more TRPs associated with the base station. 
     Another apparatus for wireless communications at a base station is described. The apparatus may include means for receiving, from a UE, one or more transmissions from at least one of multiple panels of the UE, determining a timing advance value for a serving cell configured for multi-panel communications based at least in part the received one or more transmissions and a reference timing configuration for the serving cell for the UE, transmitting, to the UE, the timing advance value, and communicating with the UE via one or more TRPs associated with the base station. 
     A non-transitory computer-readable medium storing code for wireless communications at a base station is described. The code may include instructions executable by a processor to receive, from a UE, one or more transmissions from at least one of multiple panels of the UE, determine a timing advance value for a serving cell configured for multi-panel communications based at least in part the received one or more transmissions and a reference timing configuration for the serving cell for the UE, transmit, to the UE, the timing advance value, and communicate with the UE via one or more TRPs associated with the base station. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the first panel may be a reference panel based on the reference timing configuration, where the transmitted timing advance value may be equal to the first timing advance value for the first panel based on determining that the first panel may be the reference panel. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, to the UE, an indication that the first panel may be the reference panel. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the indication is transmitted via at least one of RRC signaling, a MAC-CE, or DCI. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first panel is associated with a first panel ID lower than a second panel ID associated with the second panel, where determining that the first panel is the reference panel is based on the first panel being associated with the first panel ID lower than the second panel ID associated with the second panel. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the first panel may be associated with a larger timing advance value than the second panel, where determining that the first panel may be the reference panel may be based on determining that the first panel may be associated with the larger timing advance. 
     Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the first panel may be associated with a smaller timing advance value than the second panel, where determining that the first panel may be the reference panel may be based on determining that the first panel may be associated with the smaller timing advance. 
     In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the transmitted timing advance value is based on an average of the first timing advance value for the first panel and the second timing advance value for the second panel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates an example of a wireless communications system that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. 
         FIG.  2    illustrates an example of a wireless communications system that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. 
         FIG.  3    illustrates example communications timelines that support timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. 
         FIG.  4    illustrates an example of a process flow that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. 
         FIGS.  5  and  6    show block diagrams of devices that support timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. 
         FIG.  7    shows a block diagram of a communications manager that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. 
         FIG.  8    shows a diagram of a system including a device that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. 
         FIGS.  9  and  10    show block diagrams of devices that support timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. 
         FIG.  11    shows a block diagram of a communications manager that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. 
         FIG.  12    shows a diagram of a system including a device that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. 
         FIGS.  13  and  14    show flowcharts illustrating methods that support timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In some wireless communications systems, a user equipment (UE) may support multi-panel communication with a base station via multiple transmission and reception points (TRPs). In some cases, for example, the UE may communicate with the base station via multiple TRPs by communicating with each TRP using a different panel of the UE. For instance, the UE may communicate with a first TRP associated with the base station using a first panel and may communicate with a second TRP associated with the base station using a second panel. To increase the likelihood for successful communications between the UE and the multiple TRPs associated with the base station, the UE may adjust the timing of uplink transmissions from the UE such that uplink transmissions from the UE are received by each TRP aligned with a downlink frame at the TRP. The UE may adjust the timing of an uplink transmission to a TRP by applying a timing advance (e.g., a timing advance value) to the uplink transmission. The timing advance value that the UE may apply to uplink transmissions may be based on the receiving TRP. For example, the first TRP and the second TRP may be associated with different timing advance values. In some cases, the base station, via one or more TRPs, may signal the multiple timing advance values that the UE may use to communicate with the TRPs associated with the base station. 
     According to aspects of the present disclosure, the base station, via one or more TRPs, may signal a timing advance value (e.g., a single timing advance value) that the UE may use to determine a timing advance value for each panel of the UE that the UE uses to communicate with a TRP associated with the base station. For example, the UE may use the received timing advance value to determine a first timing advance value that the UE may use for uplink transmissions from the first panel of the UE to the first TRP and to determine a second timing advance value that the UE may use for uplink transmissions from the second panel of the UE to the second TRP. In some examples, the UE may use the received timing advance value and a timing of a number of downlink signals (e.g., a number of multi-panel downlink receptions) to determine the timing advance values for each panel of the UE. In such examples, the UE may determine the timing advance value for one or more panels of the UE based on determining an offset from the received timing advance value. In some implementations, the UE may determine the offset based on measuring a time duration between downlink signals received at each of the panels of the UE. 
     Particular aspects of the subject matter described herein may be implemented to realize one or more potential advantages. The described techniques may support efficient signaling of timing advance values that a UE may use to communicate with multiple TRPs via multiple panels of the UE. Accordingly, the UE and the base station may reduce signaling overhead and improve spectral efficiency while maintaining the high reliability, coverage, and capacity associated with communicating via multiple TRPs. Further, based on receiving fewer timing advance values (e.g., based on receiving a single timing advance value instead of a timing advance value for each panel of the UE), the UE may monitor fewer resources for signaling from the base station and, as such, may power off one or more components to achieve greater power savings and longer battery life. Likewise, the base station, via the multiple TRPs, may perform fewer transmissions and, as such, may similarly achieve greater power savings as well as decrease interference in the system. 
     Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are additionally described in the context of communication timelines and a process flow. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to timing advance indication for multi-panel uplink transmission. 
       FIG.  1    illustrates an example of a wireless communications system  100  that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. The wireless communications system  100  may include one or more base stations  105 , one or more UEs  115 , and a core network  130 . In some examples, the wireless communications system  100  may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communications system  100  may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof. 
     The base stations  105  may be dispersed throughout a geographic area to form the wireless communications system  100  and may be devices in different forms or having different capabilities. The base stations  105  and the UEs  115  may wirelessly communicate via one or more communication links  125 . Each base station  105  may provide a coverage area  110  over which the UEs  115  and the base station  105  may establish one or more communication links  125 . The coverage area  110  may be an example of a geographic area over which a base station  105  and a UE  115  may support the communication of signals according to one or more radio access technologies. 
     The UEs  115  may be dispersed throughout a coverage area  110  of the wireless communications system  100 , and each UE  115  may be stationary, or mobile, or both at different times. The UEs  115  may be devices in different forms or having different capabilities. Some example UEs  115  are illustrated in  FIG.  1   . The UEs  115  described herein may be able to communicate with various types of devices, such as other UEs  115 , the base stations  105 , or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment), as shown in  FIG.  1   . 
     The base stations  105  may communicate with the core network  130 , or with one another, or both. For example, the base stations  105  may interface with the core network  130  through one or more backhaul links  120  (e.g., via an S1, N2, N3, or other interface). The base stations  105  may communicate with one another over the backhaul links  120  (e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations  105 ), or indirectly (e.g., via core network  130 ), or both. In some examples, the backhaul links  120  may be or include one or more wireless links. 
     One or more of the base stations  105  described herein may include or may be referred to by a person having ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next-generation NodeB or a giga-NodeB (either of which may be referred to as a gNB), a Home NodeB, a Home eNodeB, or other suitable terminology. 
     A UE  115  may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client, among other examples. A UE  115  may also include or may be referred to as a personal electronic device such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, a UE  115  may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which may be implemented in various objects such as appliances, or vehicles, meters, among other examples. 
     The UEs  115  described herein may be able to communicate with various types of devices, such as other UEs  115  that may sometimes act as relays as well as the base stations  105  and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in  FIG.  1   . 
     The UEs  115  and the base stations  105  may wirelessly communicate with one another via one or more communication links  125  over one or more carriers. The term “carrier” may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication links  125 . For example, a carrier used for a communication link  125  may include a portion of a radio frequency spectrum band (e.g., a bandwidth part (BWP)) that is operated according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling that coordinates operation for the carrier, user data, or other signaling. The wireless communications system  100  may support communication with a UE  115  using carrier aggregation or multi-carrier operation. A UE  115  may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both frequency division duplexing (FDD) and time division duplexing (TDD) component carriers. 
     In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers. A carrier may be associated with a frequency channel (e.g., an evolved universal mobile telecommunication system terrestrial radio access (E-UTRA) absolute radio frequency channel number (EARFCN)) and may be positioned according to a channel raster for discovery by the UEs  115 . A carrier may be operated in a standalone mode where initial acquisition and connection may be conducted by the UEs  115  via the carrier, or the carrier may be operated in a non-standalone mode where a connection is anchored using a different carrier (e.g., of the same or a different radio access technology). 
     The communication links  125  shown in the wireless communications system  100  may include uplink transmissions from a UE  115  to a base station  105 , or downlink transmissions from a base station  105  to a UE  115 . Carriers may carry downlink or uplink communications (e.g., in an FDD mode) or may be configured to carry downlink and uplink communications (e.g., in a TDD mode). 
     A carrier may be associated with a particular bandwidth of the radio frequency spectrum, and in some examples the carrier bandwidth may be referred to as a “system bandwidth” of the carrier or the wireless communications system  100 . For example, the carrier bandwidth may be one of a number of determined bandwidths for carriers of a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz)). Devices of the wireless communications system  100  (e.g., the base stations  105 , the UEs  115 , or both) may have hardware configurations that support communications over a particular carrier bandwidth or may be configurable to support communications over one of a set of carrier bandwidths. In some examples, the wireless communications system  100  may include base stations  105  or UEs  115  that support simultaneous communications via carriers associated with multiple carrier bandwidths. In some examples, each served UE  115  may be configured for operating over portions (e.g., a sub-band, a BWP) or all of a carrier bandwidth. 
     Signal waveforms transmitted over a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a resource element may consist of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both). Thus, the more resource elements that a UE  115  receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE  115 . A wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers or beams), and the use of multiple spatial layers may further increase the data rate or data integrity for communications with a UE  115 . 
     One or more numerologies for a carrier may be supported, where a numerology may include a subcarrier spacing (Δf) and a cyclic prefix. A carrier may be divided into one or more BWPs having the same or different numerologies. In some examples, a UE  115  may be configured with multiple BWPs. In some examples, a single BWP for a carrier may be active at a given time and communications for the UE  115  may be restricted to one or more active BWPs. 
     The time intervals for the base stations  105  or the UEs  115  may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of T s =1/(Δf max ·N f ) seconds, where Δf max  may represent the maximum supported subcarrier spacing, and Δf f  may represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of a communications resource may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023). 
     Each frame may include multiple consecutively numbered subframes or slots, and each subframe or slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a number of slots. Alternatively, each frame may include a variable number of slots, and the number of slots may depend on subcarrier spacing. Each slot may include a number of symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period). In some wireless communications systems  100 , a slot may further be divided into multiple mini-slots containing one or more symbols. Excluding the cyclic prefix, each symbol period may contain one or more (e.g., N f ) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or frequency band of operation. 
     A subframe, a slot, a mini-slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system  100  and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communications system  100  may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)). 
     Physical channels may be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET)) for a physical control channel may be defined by a number of symbol periods and may extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) may be configured for a set of the UEs  115 . For example, one or more of the UEs  115  may monitor or search control regions for control information according to one or more search space sets, and each search space set may include one or multiple control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to a number of control channel resources (e.g., control channel elements (CCEs)) associated with encoded information for a control information format having a given payload size. Search space sets may include common search space sets configured for sending control information to multiple UEs  115  and UE-specific search space sets for sending control information to a specific UE  115 . 
     Each base station  105  may provide communication coverage via one or more cells, for example a macro cell, a small cell, a hot spot, or other types of cells, or any combination thereof. The term “cell” may refer to a logical communication entity used for communication with a base station  105  (e.g., over a carrier) and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID), or others). In some examples, a cell may also refer to a geographic coverage area  110  or a portion of a geographic coverage area  110  (e.g., a sector) over which the logical communication entity operates. Such cells may range from smaller areas (e.g., a structure, a subset of structure) to larger areas depending on various factors such as the capabilities of the base station  105 . For example, a cell may be or include a building, a subset of a building, or exterior spaces between or overlapping with geographic coverage areas  110 , among other examples. 
     A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by the UEs  115  with service subscriptions with the network provider supporting the macro cell. A small cell may be associated with a lower-powered base station  105 , as compared with a macro cell, and a small cell may operate in the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unrestricted access to the UEs  115  with service subscriptions with the network provider or may provide restricted access to the UEs  115  having an association with the small cell (e.g., the UEs  115  in a closed subscriber group (CSG), the UEs  115  associated with users in a home or office). A base station  105  may support one or multiple cells and may also support communications over the one or more cells using one or multiple component carriers. 
     In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB)) that may provide access for different types of devices. 
     In some examples, a base station  105  may be movable and therefore provide communication coverage for a moving geographic coverage area  110 . In some examples, different geographic coverage areas  110  associated with different technologies may overlap, but the different geographic coverage areas  110  may be supported by the same base station  105 . In other examples, the overlapping geographic coverage areas  110  associated with different technologies may be supported by different base stations  105 . The wireless communications system  100  may include, for example, a heterogeneous network in which different types of the base stations  105  provide coverage for various geographic coverage areas  110  using the same or different radio access technologies. 
     The wireless communications system  100  may support synchronous or asynchronous operation. For synchronous operation, the base stations  105  may have similar frame timings, and transmissions from different base stations  105  may be approximately aligned in time. For asynchronous operation, the base stations  105  may have different frame timings, and transmissions from different base stations  105  may, in some examples, not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations. 
     Some UEs  115 , such as MTC or IoT devices, may be low cost or low complexity devices and may provide for automated communication between machines (e.g., via Machine-to-Machine (M2M) communication). M2M communication or MTC may refer to data communication technologies that allow devices to communicate with one another or 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 such information to a central server or application program that makes use of the information or presents the information to humans interacting with the application program. Some UEs  115  may be designed to collect information or enable automated behavior of machines or other devices. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging. 
     Some UEs  115  may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception simultaneously). In some examples, half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for the UEs  115  include entering a power saving deep sleep mode when not engaging in active communications, operating over a limited bandwidth (e.g., according to narrowband communications), or a combination of these techniques. For example, some UEs  115  may be configured for operation using a narrowband protocol type that is associated with a defined portion or range (e.g., set of subcarriers or resource blocks (RBs)) within a carrier, within a guard-band of a carrier, or outside of a carrier. 
     The wireless communications system  100  may be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof. For example, the wireless communications system  100  may be configured to support ultra-reliable low-latency communications (URLLC) or mission critical communications. The UEs  115  may be designed to support ultra-reliable, low-latency, or critical functions (e.g., mission critical functions). Ultra-reliable communications may include private communication or group communication and may be supported by one or more mission critical services such as mission critical push-to-talk (MCPTT), mission critical video (MCVideo), or mission critical data (MCData). Support for mission critical functions may include prioritization of services, and mission critical services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission critical, and ultra-reliable low-latency may be used interchangeably herein. 
     In some examples, a UE  115  may also be able to communicate directly with other UEs  115  over a device-to-device (D2D) communication link  135  (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs  115  utilizing D2D communications may be within the geographic coverage area  110  of a base station  105 . Other UEs  115  in such a group may be outside the geographic coverage area  110  of a base station  105  or be otherwise unable to receive transmissions from a base station  105 . In some examples, groups of the UEs  115  communicating via D2D communications may utilize a one-to-many (1:M) system in which each UE  115  transmits to every other UE  115  in the group. In some examples, a base station  105  facilitates the scheduling of resources for D2D communications. In other cases, D2D communications are carried out between the UEs  115  without the involvement of a base station  105 . 
     In some systems, the D2D communication link  135  may be an example of a communication channel, such as a sidelink communication channel, between vehicles (e.g., UEs  115 ). In some examples, vehicles may communicate using vehicle-to-everything (V2X) communications, vehicle-to-vehicle (V2V) communications, or some combination of these. A vehicle may signal information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information relevant to a V2X system. In some examples, vehicles in a V2X system may communicate with roadside infrastructure, such as roadside units, or with the network via one or more network nodes (e.g., base stations  105 ) using vehicle-to-network (V2N) communications, or with both. 
     The core network  130  may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network  130  may be an evolved packet core (EPC) or 5G core (5GC), which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW), a Packet Data Network (PDN) gateway (P-GW), or a user plane function (UPF)). The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs  115  served by the base stations  105  associated with the core network  130 . User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions. The user plane entity may be connected to the network operators IP services  150 . The operators IP services  150  may include access to the Internet, Intranet(s), an IP Multimedia Subsystem (IMS), or a Packet-Switched Streaming Service. 
     Some of the network devices, such as a base station  105 , may include subcomponents such as an access network entity  140 , which may be an example of an access node controller (ANC). Each access network entity  140  may communicate with the UEs  115  through one or more other access network transmission entities  145 , which may be referred to as radio heads, smart radio heads, or transmission/reception points (TRPs). Each access network transmission entity  145  may include one or more antenna panels. In some configurations, various functions of each access network entity  140  or base station  105  may be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., a base station  105 ). 
     The wireless communications system  100  may operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length. The UHF waves may be blocked or redirected by buildings and environmental features, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs  115  located indoors. The transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz. 
     The wireless communications system  100  may also operate in a super high frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as the centimeter band, or in an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz), also known as the millimeter band. In some examples, the wireless communications system  100  may support millimeter wave (mmW) communications between the UEs  115  and the base stations  105 , and EHF antennas of the respective devices may be smaller and more closely spaced than UHF antennas. In some examples, this may facilitate use of antenna arrays within a device. The propagation of EHF transmissions, however, may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body. 
     The wireless communications system  100  may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communications system  100  may employ License Assisted Access (LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in unlicensed radio frequency spectrum bands, devices such as the base stations  105  and the UEs  115  may employ carrier sensing for collision detection and avoidance. In some examples, operations in unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating in a licensed band (e.g., LAA). Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among other examples. 
     A base station  105  or a UE  115  may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of a base station  105  or a UE  115  may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with a base station  105  may be located in diverse geographic locations. A base station  105  may have an antenna array with a number of rows and columns of antenna ports that the base station  105  may use to support beamforming of communications with a UE  115 . Likewise, a UE  115  may have one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, an antenna panel may support radio frequency beamforming for a signal transmitted via an antenna port. 
     The base stations  105  or the UEs  115  may use MIMO communications to exploit multipath signal propagation and increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such techniques may be referred to as spatial multiplexing. The multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO), where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO), where multiple spatial layers are transmitted to multiple devices. 
     Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station  105 , a UE  115 ) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that some signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying amplitude offsets, phase offsets, or both to signals carried via the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation). 
     A base station  105  or a UE  115  may use beam sweeping techniques as part of beam forming operations. For example, a base station  105  may use multiple antennas or antenna arrays (e.g., antenna panels) to conduct beamforming operations for directional communications with a UE  115 . Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station  105  multiple times in different directions. For example, the base station  105  may transmit a signal according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by a transmitting device, such as a base station  105 , or by a receiving device, such as a UE  115 ) a beam direction for later transmission or reception by the base station  105 . 
     Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station  105  in a single beam direction (e.g., a direction associated with the receiving device, such as a UE  115 ). In some examples, the beam direction associated with transmissions along a single beam direction may be determined based on a signal that was transmitted in one or more beam directions. For example, a UE  115  may receive one or more of the signals transmitted by the base station  105  in different directions and may report to the base station  105  an indication of the signal that the UE  115  received with a highest signal quality or an otherwise acceptable signal quality. 
     In some examples, transmissions by a device (e.g., by a base station  105  or a UE  115 ) may be performed using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmission (e.g., from a base station  105  to a UE  115 ). The UE  115  may report feedback that indicates precoding weights for one or more beam directions, and the feedback may correspond to a configured number of beams across a system bandwidth or one or more sub-bands. The base station  105  may transmit a reference signal (e.g., a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS)), which may be precoded or unprecoded. The UE  115  may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook). Although these techniques are described with reference to signals transmitted in one or more directions by a base station  105 , a UE  115  may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE  115 ) or for transmitting a signal in a single direction (e.g., for transmitting data to a receiving device). 
     A receiving device (e.g., a UE  115 ) may try multiple receive configurations (e.g., directional listening) when receiving various signals from the base station  105 , such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or by 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 configurations or receive directions. In some examples, a receiving device may use a single receive configuration to receive along a single beam direction (e.g., when receiving a data signal). The single receive configuration may be aligned in a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio (SNR), or otherwise acceptable signal quality based on listening according to multiple beam directions). 
     The wireless communications system  100  may be a packet-based network that operates according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate over logical channels. A Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use error detection techniques, error correction techniques, or both to support retransmissions at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE  115  and a base station  105  or a core network  130  supporting radio bearers for user plane data. At the physical layer, transport channels may be mapped to physical channels. 
     The UEs  115  and the base stations  105  may support retransmissions of data to increase the likelihood that data is received successfully. Hybrid automatic repeat request (HARQ) feedback is one technique for increasing the likelihood that data is received correctly over a communication link  125 . HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ may improve throughput at the MAC layer in poor radio conditions (e.g., low signal-to-noise conditions). In some examples, a device may support same-slot HARQ feedback, where the device may provide HARQ feedback in a specific slot for data received in a previous symbol in the slot. In other cases, the device may provide HARQ feedback in a subsequent slot, or according to some other time interval. 
     In some cases, a base station  105  may be associated with multiple TRPs and a UE  115  may communicate with the base station  105  via the multiple TRPs. The UE  115  may support multi-panel communication and may communicate with each of the multiple TRPs using a different panel of the UE  115 . A panel of the UE  115  may refer to an antenna configuration of the UE  115  and, as such, may equivalently be referred to as an antenna panel. A group of antenna elements, which may include two or more antenna elements in one or more antenna arrays or sub-arrays may be referred to herein as an antenna panel, which may correspond to a physical antenna panel or hardware module at a UE or to a virtual antenna panel that may include two or more antenna elements that are a subset of antenna elements at a physical antenna module or that span multiple antenna modules. Each antenna panel may include antenna elements associated with one or more polarizations. In some cases, an antenna panel may include beamforming capability (e.g., analog beamforming components such as phase shifters or configurable amplifiers). In some cases, each antenna panel may be associated with one or more radio frequency chains, which may, for example, convert between radio frequency signals and digital baseband signals. 
     TRPs that are associated with the base station  105  may include or otherwise refer to TRPs located at the same physical location as the base station  105  (e.g., TRPs that are a part of the base station  105 ) or TRPs located at various physical locations that the base station  105  may use to communicate with the UE  115  (e.g., such as a relay node). Alternatively, a TRP may refer to the base station  105  and, in such cases, the UE  115  may communicate with multiple base stations  105 . 
     In some implementations of the present disclosure, the base station  105  may receive one or more transmissions from the UE  115  and may measure or otherwise determine a timing advance value for each panel of the UE  115  that the UE  115  uses to communicate with the multiple TRPs associated with the base station  105 . The base station  105  may determine a timing advance value (e.g., a single timing advance value) based on the measured timing advance values for each panel of the UE  115  and may transmit the timing advance value (e.g., the single timing advance value) to the UE  115 . The UE  115  may use the received timing advance value and a timing of at least one downlink signal received via at least one of the multiple panels of the UE  115  to derive or otherwise determine a timing advance value for each panel of the UE  115 . Accordingly, the UE  115  may apply the derived timing advance values for each panel of the UE  115  to communicate with the base station  105  via the multiple TRPs associated with the base station  105 . 
       FIG.  2    illustrates an example of a wireless communications system  200  that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. In some examples, the wireless communications system  200  may implement aspects of the wireless communications system  100 . 
     The wireless communications system  200  may include a base station  105 - a  and a UE  115 - a,  which may be examples of corresponding devices as described herein. The base station  105 - a  may be associated with a TRP  205  and a TRP  210 , which may be physically located at the base station  105 - a  or at a location remote from the base station  105 - a,  and usable by the base station  105 - a  to communicate with the UE  115 - a.  The UE  115 - a  may communicate with the TRP  205  and the TRP  210  using a panel  235  and a panel  240 , respectively. For example, the UE  115 - a  may use the panel  235  to transmit uplink signals  255  over an uplink communication link  220  to the TRP  205  and to receive downlink signals  250  over a downlink communication link  215  from the TRP  205 . Similarly, the UE  115 - a  may use the panel  240  to transmit uplink signals  265  over an uplink communication link  230  to the TRP  210  and to receive downlink signals  260  over a downlink communication link  225  from the TRP  210 . In some examples, the UE  115 - a  may receive a timing advance value  245  from the base station  105 - a  (e.g., via the TRP  205 , as shown, via the TRP  210 , or via any other signaling) and the UE  115 - a  may use the timing advance value  245  to determine a timing advance value for communications from each of the panel  235  and the panel  240 . 
     The base station  105 - a  may host a serving cell for the UE  115 - a  and, accordingly, may be referred to herein as a serving base station  105 - a.  The UE  115 - a  may be configured to support multi-panel uplink communication with the base station  105 - a  and may communicate with the TRP  205  and the TRP  210  associated with the base station  105 - a  using different panels of the UE  115 - a,  such as the panel  235  and the panel  240 , respectively. In some cases, TRP  205  and TRP  210  may be synchronized with the downlink timing of the base station  105 - a  (e.g., transmitting and receiving signals according to a synchronized frame timing). In such cases, the base station  105 - a  may transmit a timing advance value  245  to the UE  115 - a  for each of the panel  235  and the panel  240  to better align signals transmitted by the UE  115 - a  with the downlink timing at the base station  105 - a  when received by the TRP  205  or TRP  210 . For example, communication between the TRP  205  and the panel  235  may be associated with a first timing advance group (TAG) (e.g., a first TAG-ID) and the base station  105 - a  may signal a first timing advance value for the UE  115 - a  to apply to communication between the TRP  205  and the panel  235 . Similarly, communication between the TRP  210  and the panel  240  may be associated with a second TAG (e.g., a second TAG-ID) and the base station  105 - a  may signal a second timing advance value for the UE  115 - a  to apply to communication between the TRP  210  and the panel  240 . For example, the TRP  205  and the TRP  210  may be at different locations (e.g., physically separate from the base station  105 - a ) or communication between the TRP  205  and the UE  115 - a  may take a different duration of time than communication between the TRP  210  and the UE  115 - a  for other reasons (e.g., different channel paths, reflections). 
     In some cases, the TRP  205  and the TRP  210  may be synchronized (e.g., timing-aligned) such that the TRP  205  and the TRP  210  may have aligned uplink frames and downlink frames. For example, the beginning of a downlink frame of the TRP  205  may be aligned with the beginning of a downlink frame of the TRP  210 . Based on being located at different locations and having alignment in time, the timing advance value that the UE  115 - a  may use to communicate with each of the TRP  205  and the TRP  210  may be different. In such examples, the UE  115 - a  may adjust the timing of a first uplink transmission (e.g., an uplink signal  255 ) from the panel  235  to the TRP  205  by the first timing advance value and may adjust the timing of a second transmission (e.g., an uplink signal  265 ) from the panel  240  to the TRP  210  by the second timing advance value, which may result in better alignment of the reception of the uplink signal  255  at the TRP  205  and a downlink frame of the TRP  205  and better alignment of the reception of the uplink signal  265  at the TRP  210  and a downlink frame of the TRP  210 . In some cases, however, signaling a different timing advance value for each TRP associated with the base station  105 - a  (e.g., for each panel of the UE  115 - a  that the UE  115 - a  uses to communicate with a TRP associated with the base station  105 - a ) may result in an increase in signaling overhead and may reduce the spectral efficiency and the achievable data rate of the wireless communications system  200 . 
     In some implementations of the present disclosure, the base station  105 - a  may signal a timing advance value  245  (e.g., a single timing advance value  245 ) that the UE  115 - a  may use to determine timing advance values for the panel  235  and the panel  240 . In some aspects, the timing advance value  245  may be associated with a TAG-ID (e.g., the UE  115 - a  may be associated with a single TAG). In such implementations, the base station  105 - a  may transmit fewer signals to the UE  115 - a,  reducing overhead and improving spectral efficiency. In some examples, the base station  105 - a  may determine the timing advance for each of the panel  235  and the panel  240  based on determining the difference (e.g., the time-domain difference) between when a transmission from the UE  115 - a  is received and the start of a downlink frame at the base station  105 - a  (which may be equivalent to the start of a downlink frame at both of the TRP  205  and the TRP  210  in the case that the TRP  205  and the TRP  210  are timing-aligned). For example, the base station  105 - a  may measure the difference between when the base station  105 - a  (e.g., via the TRP  205 ) receives an uplink signal  255  and the beginning of a downlink frame at the base station  105 - a  to determine a first timing advance value for the panel  235 . Similarly, the base station  105 - a  may measure the difference between when the base station  105 - a  (e.g., via the TRP  210 ) receives an uplink signal  265  and the beginning of a downlink frame at the base station  105 - a  to determine a second timing advance value for the panel  240 . 
     The base station  105 - a  may use the first timing advance value for the panel  235  and the second timing advance value for the panel  240  to determine the timing advance value  245  that the base station  105 - a  may transmit to the UE  115 - a.  In some examples, the base station  105 - a  may determine the timing advance value  245  based on the first timing advance value, the second timing advance value, and a reference timing configuration for the serving cell (e.g., for the serving base station  105 - a ). The reference timing configuration may indicate how the base station  105 - a  may determine the timing advance value  245 . For example, in some implementations, the reference timing configuration may indicate that the base station  105 - a  may determine the timing advance value  245  based on equating the timing advance value  245  to the timing advance value of a reference or a default panel (e.g., either the first timing advance value for the panel  235  or the second timing advance value for the panel  240 ). For instance, in the case that the panel  235  is the reference panel, the timing advance value  245  may equal the first timing advance value that the base station  105 - a  measures for communication between the TRP  205  and the panel  235  of the UE  115 - a.  In some other implementations, the reference timing configuration may indicate that the base station  105 - a  may determine the timing advance value  245  based on the mean (e.g., the average) of the first timing advance value and the second timing advance value. For example, the base station  105 - a  may average the first timing advance value and the second timing advance value and may set the timing advance value  245  equal to the average. In some aspects, the reference timing configuration may be configured at both the base station  105 - a  and the UE  115 - a  (e.g., pre-configured or signaled). 
     The UE  115 - a  may receive the timing advance value  245  and determine the first timing advance value for the panel  235  and the second timing advance value for the panel  240  based on the received timing advance value  245  and a timing of at least one of the downlink signal  250  or the downlink signal  260  received via the panel  235  or the panel  240 , respectively. In some examples, the UE  115 - a  may determine the first timing advance value for the panel  235  and the second panel  240  based on the reference timing configuration. For example, the method, technique, algorithm, or process for determining the first timing advance value and the second timing advance value may be based on whether the timing advance value  245  is equal to a timing advance value for a reference panel (e.g., the first timing advance value for the panel  235  or the second timing advance value for the panel  240 ) or equal to an average of the first timing advance value for the panel  235  and the second timing advance value for the panel  240 . Additional details relating to determining the first timing advance value for the panel  235  and the second timing advance value for the panel  240  are described herein, including with reference to  FIG.  3   . 
     Accordingly, the UE  115 - a  may communicate with the TRP  205  and the TRP  210  associated with the base station  105 - a  based on the first timing advance value for the panel  235  and the second timing advance value for the panel  240 . For example, the UE  115 - a  may apply the first timing advance value to communication (e.g., uplink signals  255 ) between the TRP  205  and the panel  235  and may apply the second timing advance value to communication (e.g., uplink signals  265 ) between the TRP  210  and the panel  240 . 
       FIG.  3    illustrates example communication timelines  300 ,  301 , and  302  that support timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. In some examples, the communication timelines  300 ,  301 , and  302  may implement aspects of the wireless communications system  100  and the wireless communications system  300 . The communications timelines  300 ,  301 , and  302  may illustrate communication between multiple TRPs associated with a base station and a UE, which may be examples of corresponding devices described herein. In some examples, the UE may determine a timing advance value for multiple panels, such as a panel  305  and a panel  310 , based on receiving a timing advance value (e.g., a single timing advance value) from the base station. 
     In some cases, the UE may communicate with a first TRP associated with the base station via the panel  305  and may communicate with a second TRP associated with the base station via the panel  310 . In some implementations, the base station may determine the timing advance value based on determining a first timing advance value for communication between the first TRP and the panel  305  of the UE (which may be referred to herein as 2*t 0 ), a second timing advance value for communication between the second TRP and the panel  310  of the UE (which may be referred to herein as 2*t 1 ), and a reference timing configuration, as described in more detail herein, including with reference to  FIG.  2   . In some examples, the reference timing configuration may indicate that the base station will set the transmitted timing advance value equal to the timing advance value for a reference panel of the UE. The reference panel of the UE may be either the panel  305  or the panel  310  based on the configuration. In some other examples, the reference timing configuration may indicate that the base station will set the transmitted timing advance value equal to an average of the first timing advance value for the panel  305  and the second timing advance value for the panel  310 . 
     In some examples in which the reference timing configuration indicates that the transmitted timing advance value is equal to the timing advance value for a reference panel, the base station and the UE may determine the reference panel based on the configuration or based on signaling. For example, in some implementations, the base station may determine the reference panel and may signal an indication of the reference panel to the UE. The base station may signal the reference panel to the UE via radio resource control (RRC) signaling, a medium access control (MAC) control element (CE), or an indication in downlink control information (DCI). In such implementations, the base station may semi-statically or dynamically update which panel of the UE is the reference panel. In some other implementations, the base station and the UE may determine the reference panel based on a fixed rule. For example, the reference panel may be determined based on a panel identifier (ID) associated with each panel of the UE. For instance, the base station and the UE may determine that the panel with the lowest panel ID is the reference panel. In some aspects, the panel ID may be reused from or associated with other signal IDs, such as a sounding reference signal (SRS) resource ID, an SRS set ID, a CORESET pool index, or a beam ID, among other examples. Although described and illustrated in an example in which the reference panel is the panel with the lowest panel ID, the described techniques may be equivalently applied to an example in which the reference panel is the panel with the highest panel ID. In some other examples, the reference panel may be defined based on the relative timing advance value for each panel. For example, the base station and the UE may determine that the panel with the relatively smaller or larger timing advance value is the reference panel. 
     In such examples in which the timing advance value transmitted by the base station is equal to the timing advance value for a reference panel, the UE may apply the received timing advance value to the reference panel (e.g., apply the received timing advance value to communication from the reference panel) and derive the timing advance for the other panel. In some examples in which the reference timing configuration indicates that the transmitted timing advance value is equal to the average of the first timing advance value and the second timing advance value, the UE may derive the timing advance value for each panel of the UE. Examples of some implementations of the present disclosure are described with reference communication timelines  300 ,  301 , and  302  and similar methods and algorithms may be used in addition, or in an alternative, to the example methods and algorithms described herein. Further, as described herein, N TAi  is to the total timing advance value for a panel i of the UE  115 - a  and may be defined as shown below in Equation 1. 
         N   TAi   =N   TA   +TA+δ   i    (1)
 
     As shown in Equation 1, N TA  is the the cumulative timing advance for a panel (e.g., based on a summation of previous timing advance values received from the base station), TA is the timing advance value received from the base station, and δ i  is an offset (e.g., in the time domain) for a panel i of the UE based on a timing of downlink signals received at the panels of the UE. In some cases, for example, the first timing advance value for the panel  305  may equivalently be defined as 2*t 0 =TA+δ 0  and the second timing advance value for the panel  310  may be defined as 2*t 1 =TA+δ 1 . 
     As illustrated by communications timeline  300 , the UE may transmit an uplink signal from each of the panel  305 - a  and the panel  310 - a  during the same time period and may receive a downlink signal via each of the panel  305 - a  and the panel  310 - a  during the same time period. In such cases, the timing advance value transmitted by the base station will apply to communications from the panel  305 - a  and the panel  310 - a  equally regardless of which panel is the reference panel. For example, the timing advance value for the panel  305 - a  and the panel  310 - a  is the same (e.g., t 0 =t 1 ). As such, the first timing advance value for the panel  305 - a  may be equal to TA (e.g., δ 0 =0) and the total timing advance value for the panel  305 - a  may be determined based on N TA0 =N TA +TA. Likewise, the second timing advance value for the panel  310 - a  may be equal to TA (e.g., δ 1 =0) and the total timing advance value for the panel  310 - a  may be determined based on N TA1 =N TA +TA. 
     As illustrated by communications timeline  301 , the UE may transmit an uplink signal from the panel  305 - b  prior to transmitting an uplink signal from the panel  310 - b  and may receive a downlink signal via the panel  310 - b  prior to receiving a downlink signal via the panel  305 - b.  Accordingly, the first timing advance value 2*t 0  may be different than the second timing advance value 2*t 1  (e.g., t 0 &gt;t 1 ) and, as such, the algorithms or methods that the UE may use to determine the first timing advance value and the second timing advance value may be based on the reference timing configuration used by the base station to determine the transmitted timing advance value. 
     In examples in which the timing advance value received by the UE is equal to the timing advance value of a reference panel and the reference panel is determined based on which panel receives a downlink signal first (e.g., which may be equivalent to which panel has the relatively smaller timing advance value), the base station and the UE may determine that the panel  310 - b  is the reference panel. For example, the UE may measure a first set of synchronization signal blocks (SSBs) which are associated with a first TRP of the base station using the panel  305 - b  and may measure a second set of SSBs which are associated with a second TRP of the base station using the panel  310 - b.  The first set of SSBs and the second set of SSBs may be transmitted from the first TRP of the base station and the second TRP of the base station, respectively. Based on the measurement, the UE may determine which panel receives a downlink signal first (e.g., the panel  310 - b  may receive the second set of SSBs before the panel  305 - b  receives the first set of SSBs). For example, the received timing advance value TA may be equal to 2*t 1  and the UE may determine that the second timing advance value for the panel  310 - b  is equal to 2*t 1  (e.g., the UE may determine that δ 1 =0 based on determining that the panel  310 - b  is the reference panel). As such, the UE may determine the second timing advance value for the panel  310 - b  based on determining N TA1 =N TA +TA. 
     The UE may determine (e.g., derive) the first timing advance value for the panel  305 - b  based on the received timing advance value and a timing of the downlink signals received via the panel  305 - b  and the panel  310 - b.  In some examples, the UE may determine the offset δ 0  between when a downlink signal is received via the panel  305 - b  and when a downlink signal is received via the panel  310 - b.  In some aspects, the UE may measure the offset between two downlink signals received at different panels of the UE that were transmitted from different TRPs associated with the base station at the same time (e.g., to achieve an accurate measure of the difference in timing advance between communications between the first TRP and the panel  305 - b  and communications between the second TRP and the panel  310 - b ). In some implementations, the UE may determine the offset δ 0  to be equal to 2*(t 0 −t 1 ). For instance, δ 0 =2*(t 0 −t 1 ). Accordingly, the UE may determine the total timing advance value for the panel  305 - b  based on determining N TA0 =N TA TA+δ 0 . 
     In examples in which the timing advance value received by the UE is equal to the timing advance value of a reference panel and the reference panel is determined based on which panel has the lower panel ID, the base station and the UE may determine that the panel  305 - b  is the reference panel (e.g., the panel  305 - b  may be associated with a lower panel ID than the panel  310 - b ). For example, the received timing advance value TA may be equal to 2*t 0  and the UE may determine that the first timing advance value for the panel  305 - b  is equal to 2*t 0  (e.g., the UE may determine that δ 0 =0 based on determining that the panel  305 - b  is the reference panel). As such, the UE may determine the first timing advance value for the panel  305 - b  based on determining N TA0 =N TA +TA. 
     The UE may determine (e.g., derive) the second timing advance value for the panel  310 - b  based on the received timing advance value and the timing of the downlink signals received via the panel  305 - b  and the panel  310 - b.  For example, the UE may determine the offset δ 1  between when a downlink signal is received via the panel  305 - b  and when a downlink signal is received via the panel  310 - b.  In some aspects, the UE may measure the offset between two downlink signals received at different panels of the UE that were transmitted from different TRPs associated with the base station at the same time. In some implementations, the UE may determine the offset δ 1  to be proportional with the time difference of receiving the two downlink signals received at different panels of the UE that were transmitted from different TRPs associated with the base station at the same time. For instance, δ 1 =2*(t 0 −t 1 ). Accordingly, the UE may determine the total timing advance value for the panel  310 - b  based on determining N TA1 =N TA +TA−δ 1 . 
     In examples in which the received timing advance value is equal to an average of the first timing advance value for the panel  305 - b  and the second timing advance value for the panel  310 - b  (e.g., TA=(2*t 0 +2*t 1 )/2=t 0 +t 1 ), the UE may derive both the first timing advance value and the second timing advance value. For example, the UE may determine a first offset δ 0  for the panel  305 - b  and a second offset δ 1  for the panel  310 - b.  In some examples, the UE may determine the first offset δ 0  based on a first difference between when a first downlink signal is received via the panel  305 - b  and when a second downlink signal is received via the panel  310 - b  and may determine the second offset δ 1  based on a second difference between when the first downlink signal is received via the panel  305 - b  and when the second downlink signal is received via the panel  310 - b.  In some aspects, for example, the first difference may be proportional with the time difference between receiving the first downlink signal at panel  305 - b  of the UE and receiving the second downlink signal at panel  310 - b  of the UE that were transmitted from different TRPs associated with the base station at the same time. For example, the second difference may be proportional with the time difference between receiving the second downlink signal at panel  310 - b  of the UE and receiving the first downlink signal at panel  305 - b  of the UE that were transmitted by different TRPs associated with the base station at the same time. For instance, δ 0 =t 0 −t 1  and δ 1 =t 1 −t 0 . The UE may determine the first timing advance value for panel  305 - b  based on the received timing advance value and the first offset and may determine the second timing advance value for panel  310 - b  based on the received timing advance value and the second offset. For example, the first timing advance value may be equal to TA+δ 0  and the second timing advance value may be equal to TA+δ 1 . Accordingly, the UE may determine the total timing advance value for the panel  305 - b  based on determining N TA0 =N TA +TA+δ 0  and may determine the total timing advance value for the panel  310 - b  based on determining N TA1 =N TA TA+δ 1 . 
     As illustrated by communications timeline  302 , the UE may transmit an uplink signal from the panel  310 - c  prior to transmitting an uplink signal from the panel  305 - c  and may receive a downlink signal via the panel  305 - c  prior to receiving a downlink signal via the panel  310 - c.  Accordingly, the first timing advance value 2*t 0  may be different than the second timing advance value 2*t 1  (e.g., t 1 &gt;t 0 ) and, as such, the algorithms or methods that the UE may use to determine the first timing advance value and the second timing advance value may be based on the reference timing configuration used by the base station to determine the transmitted timing advance value. 
     In examples in which the the timing advance value received by the UE is equal to the timing advance value of a reference and the reference panel is determined based on which panel receives a downlink signal first (e.g., which may be equivalent to which panel has the relatively smaller timing advance value), the base station and the UE may determine that the panel  305 - c  is the reference panel. For example, the received timing advance value TA may be equal to 2*t 0  and the UE may determine that the first timing advance value for the panel  305 - c  is equal to 2*t 0  (e.g., the UE may determine that δ 0 =0 based on determining that the panel  305 - c  is the reference panel). As such, the UE may determine the total timing advance value for the panel  305 - c  based on determining N TA0 =N TA +TA. 
     The UE may determine (e.g., derive) the second timing advance value for the panel  310 - c  based on the received timing advance value and a timing of the downlink signals received via the panel  305 - c  and the panel  310 - c.  In some examples, the UE may determine an offset δ 1  between when a downlink signal is received via the panel  305 - c  and when a downlink signal is received via the panel  310 - c.  In some aspects, the UE may measure the offset δ 1  between two downlink signals received at different panels of the UE that were transmitted from different TRPs associated with the base station at the same time (e.g., to achieve an accurate measure of the difference in timing advance between communications between the first TRP and the panel  305 - c  and communications between the second TRP and the panel  310 - c ). In some implementations, the UE may determine the offset δ 1  to be proportional with the time difference of receiving two downlink signals received at different panels of the UE that were transmitted from different TRPs associated with the base station at the same time. For instance, δ 1 =2*(t 1 −t 0 ). Accordingly, the UE may determine the total timing advance value for the panel  310 - c  based on determining N TA1 =N TA +TA+δ 1 . 
     In examples in which the timing advance value received by the UE is equal to the timing advance value of a reference panel and the reference panel is determined based on which panel has the lower panel ID, the base station and the UE may determine that the panel  305 - c  is the reference panel (e.g., the panel  305 - c  may be associated with a lower panel ID than the panel  310 - c ). For example, the received timing advance value TA may be equal to 2*t 0  and the UE may determine that the first timing advance value for the panel  305 - c  is equal to 2*t 0  (e.g., the UE may determine that δ 0 =0 based on determining that the panel  305 - c  is the reference panel). As such, the UE may determine the total timing advance value for the panel  305 - c  based on determining N TA0 =N TA +TA. 
     The UE may determine (e.g., derive) the second timing advance value for the panel  310 - c  based on the received timing advance value and the timing of the downlink signals received via the panel  305 - c  and the panel  310 - c.  For example, the UE may determine an offset δ 1  between when a downlink signal is received via the panel  305 - c  and when a downlink signal is received via the panel  310 - c.  In some aspects, the UE may measure the offset δ 1  based on the time difference between two downlink signals received at different panels of the UE that were transmitted from different TRPs associated with the base station at the same time. In some implementations, the UE may determine the offset δ 1  to be proportional with the time difference between receiving the first downlink signal at the reference panel (e.g., panel  305 - c ) of the UE and receiving the downlink downlink signal at the other panel (e.g., panel  310 - c ) of the UE that were transmitted from different TRPs associated with the base station at the same time. For instance, δ 1 =2*(t 1 −t 0 ). Accordingly, the UE may determine the total timing advance value for the panel  310 - c  based on determining N TA1 =N TA +TA+δ 1 . 
     In examples in which the received timing advance value is equal to an average of the first timing advance value for the panel  305 - c  and the second timing advance value for the panel  310 - c  (e.g., TA=(2*t 0 +2*t 1 )/2=t 0 +t 1 ), the UE may derive both the first timing advance value and the second timing advance value. For example, the UE may determine a first offset δ 0  for the panel  305 - c  and a second offset δ 1  for the panel  310 - c.  In some examples, the UE may determine the first offset δ 0  based on a first difference between when a first downlink signal is received via panel  305 - c  and when a second downlink signal is received via panel  310 - b  and may determine the second offset δ 1  based on a second difference between when the first downlink signal is received via panel  305 - c  and when the second downlink signal is received via panel  310 - c.  In some aspects, for example, the first difference may be proportional with the time difference between receiving the first downlink signal at panel  305 - c  of the UE and receiving the second downlink signal at panel  310 - c  of the UE that were transmitted from different TRPs associated with the base station at the same time. For example, the second difference may be proportional with the time difference between receiving the second downlink signal at panel  310 - c  of the UE and receiving the first downlink signal at panel  305 - c  of the UE that were transmitted from different TRPs associated with the base station at the same time. For instance, the first difference may refer to t 0 −t 1  and the second difference may refer to t 1 −t 0 . Accordingly, δ 0 =t 0 −t 1  and δ 1 =t 1 −t 0 . The UE may determine the first timing advance value for the panel  305 - c  based on the received timing advance value and the first offset and may determine the second timing advance value for the panel  310 - c  based on the received timing advance value and the second offset. For example, the first timing advance value may be equal to the TA+(t 0 −t 1 ) and the second timing advance value may be equal to TA+(t 1 −t 0 ). Accordingly, the UE may determine the total timing advance value for the panel  305 - c  based on determining N TA0 =N TA +TA+(t 0 −t 1 ) and may determine the total timing advance value for the panel  310 - c  based on determining N TA1 =N TA +TA+(t 1 −t 0 ). 
     As such, the UE may determine the first timing advance value for a panel  305  and the second timing advance value for a panel  310  and the UE may apply the determined timing advance values to communication between the first TRP associated with the base station and the panel  305  and to communication between the second TRP associated with the base station and the panel  310 , respectively. As such, the base station may receive uplink signals from the UE better aligned with downlink frames maintained at the base station, which may increase the reliability of communications between the base station and the UE. Although described herein in the context of two panels (e.g., the panel  305  and the panel  310 ), the described techniques may apply to any number of panels. For example, the UE may receive a timing advance value from the base station and may determine any number of timing advance values for any number of panels of the UE based on the received timing advance value and a timing of downlink signals received at the different panels of the UE. 
       FIG.  4    illustrates an example of a process flow  400  that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. In some examples, the process flow  400  may implement aspects of the wireless communications system  100  and the wireless communication system  200 . The process flow  400  may illustrate communication between a base station  105 - b  and a UE  115 - b,  which may be examples of corresponding devices as described herein. In some implementations, the UE  115 - b  may receive a timing advance value from the base station  105 - b  and may derive a timing advance value for each panel of the UE  115 - b  based on the received timing advance value and a timing of downlink signals received at different panels of the UE  115 - b.    
     At  405 , the UE  115 - a  may transmit one or more uplink signals to the base station  105 - b.  For example, the UE  115 - a  may transmit one or more transmissions from at least one of the multiple panels of the UE  115 - b.  In some aspects, the UE  115 - a  may transmit a first uplink signal from a first panel of the UE  115 - b  to a first TRP associated with the base station  105 - b  and a second uplink signal from a second panel of the UE  115 - b  to a second TRP associated with the base station  105 - b.    
     At  410 , the base station  105 - b  may determine a timing advance value for a serving cell configured for multi-panel communications based on the received one or more uplink signals (e.g., the one or more transmissions) from the UE  115 - b  and a reference timing configuration for the serving cell for the UE  115 - b.  The reference timing configuration may indicate that the base station  105 - b  will determine the timing advance value such that the timing advance value is equal to a timing advance value of a reference panel of the UE  115 - b  or equal to an average of the timing advance values for the panels of the UE  115 - b,  as described in more detail herein, including with reference to  FIGS.  2  and  3   . 
     At  415 , the base station  105 - b  may, in some implementations, transmit an indication of the reference panel to the UE  115 - b.  For example, the base station  105 - b  may transmit an indication that the first panel of the UE  115 - b  is the reference panel. The base station  105 - b  may transmit the indication of the reference panel to the UE  115 - b  via RRC signaling, a MAC-CE, or in an indication in DCI. 
     At  420 , the base station  105 - b  may transmit the timing advance value to the UE  115 - b.  The timing advance value may be a timing advance value for the serving cell configured for multi-panel communications. 
     At  425 , the UE  115 - b  may determine a first timing advance value for the first panel and a second timing advance value for the second panel based on the received timing advance value and a timing of at least one of a first downlink signal received via the first panel or a second downlink signal received via the second panel. In some examples, the UE  115 - b  may determine the first timing advance value and the second timing advance value based on the reference timing configuration. For example, the UE  115 - b  may identify a method or algorithm that the UE  115 - b  may use to determine the first timing advance value and the second timing advance value based on the reference timing configuration. 
     In some implementations, the received timing advance value may be equal to a timing advance value for a reference panel of the UE  115 - b  and the UE  115 - b  may determine the first timing advance value and the second timing advance value based on determining the reference panel. In some examples, the UE  115 - b  may determine the reference panel of the UE  115 - b  based on the signaling from the base station  105 - b  at  415 . In some other examples, the UE  115 - b  may determine which panel is associated with the lower panel ID. For example, the UE  115 - b  may determine that the first panel is associated with a lower panel ID and may determine that the first panel is the reference panel based on the first panel being associated with the lower panel ID. In some other examples, the UE  115 - b  may determine the reference panel based on which panel receives a downlink signal first or which panel receives a downlink signal last. For example, the UE  115 - b  may receive the first downlink signal via the first panel after receiving the second downlink signal via the second panel and the UE  115 - b  may determine that the first panel is the reference panel based on receiving the first downlink signal after the second downlink signal. Alternatively, the UE  115 - b  may receive the first downlink signal via the first panel prior to receiving the second downlink signal via the second panel and the UE  115 - b  may determine that the first panel is the reference panel based on receiving the first downlink signal prior to the second downlink signal. Upon determining the reference panel of the UE  115 - b  (e.g., upon determining that the first panel is the reference panel), the UE  115 - b  may derive the timing advance value for each remaining panel (e.g., the second panel) based on determining an offset from the received timing advance value based on the timing of the downlink signals received via the first panel and the second panel of the UE  115 - b.    
     In some other implementations, the received timing advance value may be equal to an average of the first timing advance value and the second timing advance value. In such implementations, the UE  115 - b  may derive the first timing advance value for the first panel and the second timing advance value for the second panel based on determining a first offset associated with the first panel and a second offset associated with the second panel based on downlink signals received via the first panel and the second panel of the UE  115 - b.  Additional details and examples relating to determining the first timing advance value for the first panel and the second timing advance value for the second panel are described herein, including with reference to  FIG.  3   . 
     At  430 , the UE  115 - b  may communicate with one or more TRPs associated with the base station  105 - b  based on the first timing advance value for the first panel and the second timing advance value for the second panel. For example, the UE  115 - b  may apply the first timing advance value to communication (e.g., uplink signaling) between the first TRP associated with the base station  105 - b  and the first panel of the UE  115 - b  and may apply the second timing advance value to communications (e.g., uplink signaling) between the second TRP associated with the base station  105 - b  and the second panel of the UE  115 - b.    
       FIG.  5    shows a block diagram  500  of a device  505  that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. The device  505  may be an example of aspects of a UE  115  as described herein. The device  505  may include a receiver  510 , a communications manager  515 , and a transmitter  520 . The device  505  may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). For example, the receive  510  may communicate with the communications manager  515  via a first link, which may be an example a wired link, a wireless link, or any other link that couples the receiver  510  and the communications manager  515 . In some examples, the receiver  510  may send a received timing advance value to the communications manager  515  via the first link. The communications manager  515  may communicate with the transmitter  520  via second a link, which may be also an example of a wired link, a wireless link, or any other link that couples the communications manager  515  and the transmitter  520 . In some examples, the communications manager  515  may send information relating to uplink signaling and timing advance values to the transmitter  520  via the second link. 
     The receiver  510  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 timing advance indication for multi-panel uplink transmission, etc.). Information may be passed on to other components of the device  505 . The receiver  510  may be an example of aspects of the transceiver  820  described with reference to  FIG.  8   . The receiver  510  may utilize a single antenna or a set of antennas. 
     The communications manager  515  may receive, from a base station, a timing advance value for a serving cell configured for multi-panel communications, determine a first timing advance value for a first panel and a second timing advance value for a second panel based on the received timing advance value and a timing of at least one of a first downlink signal received via the first panel or a second downlink signal received via the second panel, and communicate with one or more TRPs associated with the base station based on the first timing advance value for the first panel and the second timing advance value for the second panel. The communications manager  515  may be an example of aspects of the communications manager  810  described herein. 
     The communications manager  515 , or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager  515 , or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC), a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. 
     The communications manager  515 , or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager  515 , or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager  515 , or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure. 
     The transmitter  520  may transmit signals generated by other components of the device  505 . In some examples, the transmitter  520  may be collocated with a receiver  510  in a transceiver module. For example, the transmitter  520  may be an example of aspects of the transceiver  820  described with reference to  FIG.  8   . The transmitter  520  may utilize a single antenna or a set of antennas. 
     In some examples, the communications manager  515  may be implemented as an integrated circuit or chipset for a mobile device modem, and the receiver  510  and the transmitter  520  may be implemented as analog components (e.g., amplifiers, filters, antennas) coupled with the mobile device modem to enable wireless transmission and reception over one or more bands. 
     The communications manager  515  as described herein may be implemented to realize one or more potential advantages. In some implementations of the present disclosure, the communications manager  515  may derive multiple timing advance values for multiple panels of the device  505  based on receiving a single timing advance value from a base station. Based on receiving a single timing advance value, the device  505  may monitor fewer resources for signaling from the base station, which may enable the device  505  to power down one or more processing components of the device  505  associated with receiving signaling from the base station for longer durations or to use resources that would have otherwise been used to receive control signaling from the base station to communicate data with the base station. As such, the device  505  may improve power savings and increase the battery life of the device  505  or improve the spectral efficiency of the communication link between the device  505  and the base station, or both. 
       FIG.  6    shows a block diagram  600  of a device  605  that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. The device  605  may be an example of aspects of a device  505 , or a UE  115  as described herein. The device  605  may include a receiver  610 , a communications manager  615 , and a transmitter  630 . The device  605  may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). 
     The receiver  610  may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to timing advance indication for multi-panel uplink transmission, etc.). Information may be passed on to other components of the device  605 . The receiver  610  may be an example of aspects of the transceiver  820  described with reference to  FIG.  8   . The receiver  610  may utilize a single antenna or a set of antennas. 
     The communications manager  615  may be an example of aspects of the communications manager  515  as described herein. The communications manager  615  may include a timing advance manager  620  and a TRP manager  625 . The communications manager  615  may be an example of aspects of the communications manager  810  described herein. 
     The timing advance manager  620  may receive, from a base station, a timing advance value for a serving cell configured for multi-panel communications and determine a first timing advance value for a first panel and a second timing advance value for a second panel based on the received timing advance value and a timing of at least one of a first downlink signal received via the first panel or a second downlink signal received via the second panel. The TRP manager  625  may communicate with one or more TRPs associated with the base station based on the first timing advance value for the first panel and the second timing advance value for the second panel. 
     The transmitter  630  may transmit signals generated by other components of the device  605 . In some examples, the transmitter  630  may be collocated with a receiver  610  in a transceiver module. For example, the transmitter  630  may be an example of aspects of the transceiver  820  described with reference to  FIG.  8   . The transmitter  630  may utilize a single antenna or a set of antennas. 
       FIG.  7    shows a block diagram  700  of a communications manager  705  that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. The communications manager  705  may be an example of aspects of a communications manager  515 , a communications manager  615 , or a communications manager  810  described herein. The communications manager  705  may include a timing advance manager  710 , a TRP manager  715 , a panel manager  720 , a reference panel manager  725 , and an offset manager  730 . Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses). 
     The timing advance manager  710  may receive, from a base station, a timing advance value for a serving cell configured for multi-panel communications. In some examples, the timing advance manager  710  may determine a first timing advance value for a first panel and a second timing advance value for a second panel based on the received timing advance value and a timing of at least one of a first downlink signal received via the first panel or a second downlink signal received via the second panel. 
     In some examples, the timing advance manager  710  may determine the second timing advance value for the second panel based on the received timing advance value and the offset. In some examples, the timing advance manager  710  may determine the first timing advance value for the first panel based on the received timing advance value and the first offset. In some examples, the timing advance manager  710  may determine the second timing advance value for the second panel based on the received timing advance value and the second offset. 
     The TRP manager  715  may communicate with one or more TRPs associated with the base station based on the first timing advance value for the first panel and the second timing advance value for the second panel. 
     The panel manager  720  may determine that the first panel is a reference panel, where applying the timing advance value to the first panel is based on determining that the first panel is the reference panel. 
     The reference panel manager  725  may receive, from the base station, an indication that the first panel is the reference panel. In some examples, the reference panel manager  725  may receive the first downlink signal via the first panel after receiving the second downlink signal via the second panel, where determining that the first panel is the reference panel is based on receiving the first downlink signal via the first panel after receiving the second downlink signal via the second panel. In some examples, the reference panel manager  725  may receive the first downlink signal via the first panel prior to receiving the second downlink signal via the second panel, where determining that the first panel is the reference panel is based on receiving the first downlink signal via the first panel prior to receiving the second downlink signal via the second panel. 
     The offset manager  730  may determine an offset based on a difference between when the first downlink signal is received by the first panel and when the second downlink signal is received by the second panel. In some examples, the offset manager  730  may determine a first offset and a second offset based on a difference between when the first downlink signal is received by the first panel and when the second downlink signal is received by the second panel. 
     In some examples, the offset manager  730  may determine the first offset based on a first difference between when the first downlink signal is received by the first panel and when the second downlink signal is received by the second panel. In some examples, the offset manager  730  may determine the second offset based on a second difference between when the first downlink signal is received by the first panel and when the second downlink signal is received by the second panel. 
       FIG.  8    shows a diagram of a system  800  including a device  805  that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. The device  805  may be an example of or include the components of device  505 , device  605 , or a UE  115  as described herein. The device  805  may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager  810 , an I/O controller  815 , a transceiver  820 , an antenna  825 , memory  830 , and a processor  840 . These components may be in electronic communication via one or more buses (e.g., bus  845 ). 
     The communications manager  810  may receive, from a base station, a timing advance value for a serving cell configured for multi-panel communications, determine a first timing advance value for a first panel and a second timing advance value for a second panel based on the received timing advance value and a timing of at least one of a first downlink signal received via the first panel or a second downlink signal received via the second panel, and communicate with one or more TRPs associated with the base station based on the first timing advance value for the first panel and the second timing advance value for the second panel. 
     The I/O controller  815  may manage input and output signals for the device  805 . The I/O controller  815  may also manage peripherals not integrated into the device  805 . In some cases, the I/O controller  815  may represent a physical connection or port to an external peripheral. In some cases, the I/O controller  815  may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. In other cases, the I/O controller  815  may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller  815  may be implemented as part of a processor. In some cases, a user may interact with the device  805  via the I/O controller  815  or via hardware components controlled by the I/O controller  815 . 
     The transceiver  820  may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver  820  may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver  820  may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas. 
     In some cases, the wireless device may include a single antenna  825 . However, in some cases the device may have more than one antenna  825 , which may be capable of concurrently transmitting or receiving multiple wireless transmissions. 
     The memory  830  may include RAM and ROM. The memory  830  may store computer-readable, computer-executable code  835  including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory  830  may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices. 
     The processor  840  may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor  840  may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor  840 . The processor  840  may be configured to execute computer-readable instructions stored in a memory (e.g., the memory  830 ) to cause the device  805  to perform various functions (e.g., functions or tasks supporting timing advance indication for multi-panel uplink transmission). 
     The code  835  may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code  835  may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code  835  may not be directly executable by the processor  840  but may cause a computer (e.g., when compiled and executed) to perform functions described herein. 
       FIG.  9    shows a block diagram  900  of a device  905  that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. The device  905  may be an example of aspects of a base station  105  as described herein. The device  905  may include a receiver  910 , a communications manager  915 , and a transmitter  920 . The device  905  may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). 
     The receiver  910  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 timing advance indication for multi-panel uplink transmission, etc.). Information may be passed on to other components of the device  905 . The receiver  910  may be an example of aspects of the transceiver  1220  described with reference to  FIG.  12   . The receiver  910  may utilize a single antenna or a set of antennas. 
     The communications manager  915  may receive, from a UE, one or more transmissions from at least one of multiple panels of the UE, determine a timing advance value for a serving cell configured for multi-panel communications based at least in part the received one or more transmissions and a reference timing configuration for the serving cell for the UE, transmit, to the UE, the timing advance value, and communicate with the UE via one or more TRPs associated with the base station. The communications manager  915  may be an example of aspects of the communications manager  1210  described herein. 
     The communications manager  915 , or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager  915 , or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC), a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. 
     The communications manager  915 , or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager  915 , or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager  915 , or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure. 
     The transmitter  920  may transmit signals generated by other components of the device  905 . In some examples, the transmitter  920  may be collocated with a receiver  910  in a transceiver module. For example, the transmitter  920  may be an example of aspects of the transceiver  1220  described with reference to  FIG.  12   . The transmitter  920  may utilize a single antenna or a set of antennas. 
     As described herein, the device  905  may determine a timing advance for each panel of a UE that the UE uses to communicate with a TRP associated with the device  905  and may signal a single timing advance value to the UE. As such, the device  905  may reduce the amount of resources the device  905  may use for control signaling to the UE, which may improve the spectral efficiency of the communication link between the device  905  and the UE. Further, the device  905 , based on reducing signaling to the UE, may also reduce the interference that may potentially be generated as a result of signaling between the device  905  and the UE, which may increase the likelihood for successful wireless communications among other devices in the cell and increase the capacity of the cell. 
       FIG.  10    shows a block diagram  1000  of a device  1005  that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. The device  1005  may be an example of aspects of a device  905 , or a base station  105  as described herein. The device  1005  may include a receiver  1010 , a communications manager  1015 , and a transmitter  1035 . The device  1005  may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses). 
     The receiver  1010  may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to timing advance indication for multi-panel uplink transmission, etc.). Information may be passed on to other components of the device  1005 . The receiver  1010  may be an example of aspects of the transceiver  1220  described with reference to  FIG.  12   . The receiver  1010  may utilize a single antenna or a set of antennas. 
     The communications manager  1015  may be an example of aspects of the communications manager  915  as described herein. The communications manager  1015  may include an uplink manager  1020 , a timing advance manager  1025 , and a TRP manager  1030 . The communications manager  1015  may be an example of aspects of the communications manager  1210  described herein. 
     The uplink manager  1020  may receive, from a UE, one or more transmissions from at least one of multiple panels of the UE. The timing advance manager  1025  may determine a timing advance value for a serving cell configured for multi-panel communications based at least in part the received one or more transmissions and a reference timing configuration for the serving cell for the UE and transmit, to the UE, the timing advance value. The TRP manager  1030  may communicate with the UE via one or more TRPs associated with the base station. 
     The transmitter  1035  may transmit signals generated by other components of the device  1005 . In some examples, the transmitter  1035  may be collocated with a receiver  1010  in a transceiver module. For example, the transmitter  1035  may be an example of aspects of the transceiver  1220  described with reference to  FIG.  12   . The transmitter  1035  may utilize a single antenna or a set of antennas. 
       FIG.  11    shows a block diagram  1100  of a communications manager  1105  that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. The communications manager  1105  may be an example of aspects of a communications manager  915 , a communications manager  1015 , or a communications manager  1210  described herein. The communications manager  1105  may include an uplink manager  1110 , a timing advance manager  1115 , a TRP manager  1120 , and a reference panel manager  1125 . Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses). 
     The uplink manager  1110  may receive, from a UE, one or more transmissions from at least one of multiple panels of the UE. 
     The timing advance manager  1115  may determine a timing advance value for a serving cell configured for multi-panel communications based at least in part the received one or more transmissions and a reference timing configuration for the serving cell for the UE. In some examples, the timing advance manager  1115  may transmit, to the UE, the timing advance value. 
     In some examples, the timing advance manager  1115  may determine that the first panel is associated with a larger timing advance value than the second panel, where determining that the first panel is the reference panel is based on determining that the first panel is associated with the larger timing advance. In some examples, the timing advance manager  1115  may determine that the first panel is associated with a smaller timing advance value than the second panel, where determining that the first panel is the reference panel is based on determining that the first panel is associated with the smaller timing advance. 
     The TRP manager  1120  may communicate with the UE via one or more TRPs associated with the base station. 
     The reference panel manager  1125  may determine that the first panel is a reference panel based on the reference timing configuration, where the transmitted timing advance value is equal to the first timing advance value for the first panel based on determining that the first panel is the reference panel. In some examples, the reference panel manager  1125  may transmit, to the UE, an indication that the first panel is the reference panel. 
       FIG.  12    shows a diagram of a system  1200  including a device  1205  that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. The device  1205  may be an example of or include the components of device  905 , device  1005 , or a base station  105  as described herein. The device  1205  may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager  1210 , a network communications manager  1215 , a transceiver  1220 , an antenna  1225 , memory  1230 , a processor  1240 , and an inter-station communications manager  1245 . These components may be in electronic communication via one or more buses (e.g., bus  1250 ). 
     The communications manager  1210  may receive, from a UE, one or more transmissions from at least one of multiple panels of the UE, determine a timing advance value for a serving cell configured for multi-panel communications based at least in part the received one or more transmissions and a reference timing configuration for the serving cell for the UE, transmit, to the UE, the timing advance value, and communicate with the UE via one or more TRPs associated with the base station. 
     The network communications manager  1215  may manage communications with the core network (e.g., via one or more wired backhaul links). For example, the network communications manager  1215  may manage the transfer of data communications for client devices, such as one or more UEs  115 . 
     The transceiver  1220  may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver  1220  may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver  1220  may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas. 
     In some cases, the wireless device may include a single antenna  1225 . However, in some cases the device may have more than one antenna  1225 , which may be capable of concurrently transmitting or receiving multiple wireless transmissions. 
     The memory  1230  may include RAM, ROM, or a combination thereof. The memory  1230  may store computer-readable code  1235  including instructions that, when executed by a processor (e.g., the processor  1240 ) cause the device to perform various functions described herein. In some cases, the memory  1230  may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices. 
     The processor  1240  may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor  1240  may be configured to operate a memory array using a memory controller. In some cases, a memory controller may be integrated into processor  1240 . The processor  1240  may be configured to execute computer-readable instructions stored in a memory (e.g., the memory  1230 ) to cause the device  1205  to perform various functions (e.g., functions or tasks supporting timing advance indication for multi-panel uplink transmission). 
     The inter-station communications manager  1245  may manage communications with other base station  105 , and may include a controller or scheduler for controlling communications with UEs  115  in cooperation with other base stations  105 . For example, the inter-station communications manager  1245  may coordinate scheduling for transmissions to UEs  115  for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communications manager  1245  may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations  105 . 
     The code  1235  may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code  1235  may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code  1235  may not be directly executable by the processor  1240  but may cause a computer (e.g., when compiled and executed) to perform functions described herein. 
       FIG.  13    shows a flowchart illustrating a method  1300  that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. The operations of method  1300  may be implemented by a UE  115  or its components as described herein. For example, the operations of method  1300  may be performed by a communications manager as described with reference to  FIGS.  5  through  8   . In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware. 
     At  1305 , the UE may receive, from a base station, a timing advance value for a serving cell configured for multi-panel communications. To receive the timing advance value, the UE may identify a resource allocation (e.g., time and frequency resources) over which the base station may transmit the timing advance value, demodulate the transmission over the resource allocation, and decode the demodulated transmission to obtain bits that indicate the timing advance value. 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 by a timing advance manager as described with reference to  FIGS.  5  through  8   . 
     In some examples, the UE may receive the timing advance value as part of a timing advance configuration for multi-panel communication for the UE. As described herein, signaling a single timing advance value to configure a timing advance for multiple panels of the UE may reduce signaling overhead and improve the spectral efficiency of a communication link between the base station and the UE (e.g., via one or more TRPs). 
     At  1310 , the UE may determine a first timing advance value for a first panel and a second timing advance value for a second panel based on the received timing advance value and a timing of at least one of a first downlink signal received via the first panel or a second downlink signal received via the second panel. The UE may use a method or an algorithm for determining the first timing advance for the first panel and the second timing advance for the second panel based on a reference timing configuration, as described in more detail with reference to  FIG.  3   . For example, the received timing advance value may be equal to the timing advance value of a reference panel of the UE or may be equal to an average of the timing advances for each panel of UE, among other examples. 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 by a timing advance manager as described with reference to  FIGS.  5  through  8   . 
     At  1315 , the UE may communicate with one or more TRPs associated with the base station based on the first timing advance value for the first panel and the second timing advance value for the second panel. For example, the UE may identify a resource allocation (e.g., time and frequency resources) for transmitting or receiving, or both, with the one or more TRPs. Such communication may include encoding, modulating, and transmitting signals to the one or more TRPs or receiving, demodulating, and decoding signals from the one or more TRPs. In some examples, the UE may apply the first timing advance value to communication (e.g., uplink signaling) from the first panel to a first TRP associated with the base station and may apply the second timing advance value to communication (e.g., uplink signaling) from the second panel to a second TRP associated with the base station. 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 by a TRP manager as described with reference to  FIGS.  5  through  8   . 
       FIG.  14    shows a flowchart illustrating a method  1400  that supports timing advance indication for multi-panel uplink transmission in accordance with aspects of the present disclosure. The operations of method  1400  may be implemented by a base station  105  or its components as described herein. For example, the operations of method  1400  may be performed by a communications manager as described with reference to  FIGS.  9  through  12   . In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware. 
     At  1405 , the base station may receive, from a UE, one or more transmissions from at least one of multiple panels of the UE. To receive the one or more transmissions from the at least one of the multiple panels of the UE, the base station may identify a resource allocation (e.g., time and frequency resources) over which the UE may transmit, demodulate the transmission over the resource allocation, and decode the demodulated transmission to obtain bits that indicate the transmission. In some examples, the one or more transmissions from the UE may refer to uplink signaling that the base station may measure to determine the timing advance value for each panel of the UE that the UE uses to communicate with TRPs associated with the base station. The operations of  1405  may be performed according to the methods described herein. In some examples, aspects of the operations of  1405  may be performed by an uplink manager as described with reference to  FIGS.  9  through  12   . 
     At  1410 , the base station may determine a timing advance value for a serving cell configured for multi-panel communications based at least in part the received one or more transmissions and a reference timing configuration for the serving cell for the UE. The base station may use a method or an algorithm for determining the timing advance value based on a reference timing configuration, as described in more detail with reference to  FIG.  3   . In some examples, the base station may set the timing advance value equal to the timing advance value of a reference panel of the UE. In some other examples, the base station may set the timing advance value equal to an average of the timing advance values for the panels of the UE. The operations of  1410  may be performed according to the methods described herein. In some examples, aspects of the operations of  1410  may be performed by a timing advance manager as described with reference to  FIGS.  9  through  12   . 
     At  1415 , the base station may transmit, to the UE, the timing advance value. To transmit the timing advance value, the base station may identify a resource allocation (e.g., time and frequency resources) over which the base station may transmit the timing advance value, encode the timing advance value to determine bits that indicate the timing advance value, and modulate the timing advance value over the resource allocation. The operations of  1415  may be performed according to the methods described herein. In some examples, aspects of the operations of  1415  may be performed by a timing advance manager as described with reference to  FIGS.  9  through  12   . 
     In some examples, the base station may transmit the timing advance value as part of a timing advance configuration for multi-panel communication for the UE. As described herein, signaling a single timing advance value to configure a timing advance for multiple panels of the UE may reduce signaling overhead and improve the spectral efficiency of a communication link between the base station and the UE (e.g., via one or more TRPs). 
     At  1420 , the base station may communicate with the UE via one or more TRPs associated with the base station. For example, the base station may identify a resource allocation (e.g., time and frequency resources) for transmitting or receiving, or both, with the UE via the one or more TRPs. Such communication may include encoding, modulating, and transmitting signals to the UE via the one or more TRPs or receiving, demodulating, and decoding signals from UE via the one or more TRPs. In some examples, the base station may receive uplink signaling from the UE aligned in time with a downlink frame at the base station based on transmitting the timing advance value to the UE. 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 by a TRP manager as described with reference to  FIGS.  9  through  12   . 
     It should be noted that the methods described herein describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined. 
     Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to various other wireless communications systems such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, as well as other systems and radio technologies not explicitly mentioned herein. 
     Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. 
     The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration). 
     The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. 
     Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include random-access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media. 
     As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of”) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on.” 
     In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label. 
     The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration,” and not “preferred” or “advantageous over other examples.” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples. 
     The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.