Patent Publication Number: US-2020281006-A1

Title: Carrier preference measurement and indication

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Indian Application No. 201941007896, filed on Feb. 28, 2019, entitled “CARRIER PREFERENCE MEASUREMENT AND INDICATION,” which is hereby expressly incorporated by reference herein. 
     BACKGROUND 
     Technical Field 
     The present disclosure relates generally to communication systems, and more particularly, to carrier allocation of carriers for transmissions in multi-carrier scenarios. 
     INTRODUCTION 
     Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems. 
     Multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is 5G New Radio (NR). 
     5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT)), and other requirements. Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There exists a need for further improvements in 5G NR technology. 
     These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies. 
     BRIEF SUMMARY 
     The following presents a simplified summary of one or more aspects to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later. 
     In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE. The apparatus may measure carrier quality on a plurality of carriers, identify a first carrier from the plurality of carriers. The first carrier may correspond to a first measured carrier quality. The apparatus may send an uplink transmission to a base station, the uplink transmission including a first carrier indicator corresponding to the first carrier, and receive an uplink grant from the base station based on the uplink transmission. The first measured carrier quality may be a highest measured carrier quality or lowest measured carrier quality. 
     In another embodiment, the apparatus may also identify a second carrier from the plurality of carriers, the second carrier may correspond to a second measured carrier quality. Additionally, the uplink transmission may include a second carrier indicator corresponding to the second carrier. The first measured carrier quality may be a highest measured carrier quality, and the second measured carrier quality may be a lowest measured carrier quality. The apparatus may also receive a downlink transmission from the base station including a DTX configuration for at least one of the first carrier and the second carrier in response to the uplink transmission. 
     In one embodiment, the uplink transmission may include a buffer status report (BSR). The apparatus may receive an indication from the base station of a BSR format, where the BSR format includes a first carrier indicator field and a second carrier indicator field. In another embodiment, the uplink transmission may include a RRC transmission. The RRC transmission may include the first carrier indicator and the second carrier indicator. The RRC transmission may include a ranked list of carrier indicators including the first carrier indicator and the second carrier indicator. In yet another embodiment, the uplink transmission may include a Medium Access Control (MAC) control element (CE), the MAC CE including the first carrier indicator and the second carrier indicator. 
     In one embodiment. the measuring of the carrier quality may include measuring self-interference within the UE. The self-interference may correspond to interference from uplink carrier transmission by the UE to one or more downlink carriers. The self-interference may correspond to a delta to an SNR caused by the self-interference. Additionally, the first carrier may correspond to an uplink carrier that causes the least amount of measurable self-interference. 
     In another embodiment, the measuring of the carrier quality may include determining a thermal metric associated with transmission on one or more uplink carriers. The thermal metric may be based a transmit power and/or a thermal measurement associated with transmission on the one or more uplink carriers. The first carrier may correspond to an uplink carrier that is associated with a transmit chain having the lowest thermal metric. The second carrier may correspond to an uplink carrier associated with a transmit chain having the highest thermal metric. 
     In yet another embodiment, the apparatus may be associated with a RAT, and the carrier quality is based on an interference metric associated non-WWAN communications. 
     In another aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a base station. The apparatus may receive an uplink transmission from a user equipment (UE), the uplink transmission may include a first carrier indicator. The first carrier indicator may correspond to a first carrier quality for a first carrier. The apparatus may also schedule uplink transmissions based on the first carrier indicator, and transmit an uplink grant from the base station based on the uplink transmission. The first carrier quality may be a highest carrier quality or a lowest carrier quality. Scheduling uplink transmissions may include adjusting a rate of uplink grants scheduled on the first carrier. 
     In an embodiment, the uplink transmission may include a second carrier indicator corresponding to a second carrier and a second carrier quality, and the first carrier quality may be a highest carrier quality, and the second carrier quality may be a lowest carrier quality. Additionally, the apparatus may transmit a DTX configuration for at least one of the first carrier and the second carrier based on the first carrier indicator and the second carrier indicator. 
     In one embodiment, the uplink transmission may be a buffer status report (BSR). The apparatus may transmit an indication of a BSR format, and the BSR format may include a first carrier indicator field and a second carrier indicator field. In another embodiment, the uplink transmission may include an RCC transmission or a Medium Access Control (MAC) control element (CE), The MAC CE may include the first carrier indicator and the second carrier indicator. 
     To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating an example of a wireless communications system and an access network according to some embodiments. 
         FIG. 2  is a diagram illustrating an example of a base station and user equipment (UE) in an access network according to some embodiments. 
         FIG. 3  illustrates a table of logical channel ID (LCID) values. 
         FIG. 4  illustrates a BSR format for communication of carrier IDs. 
         FIG. 5  is a diagram illustrating a base station in communication with a UE according to some embodiments. 
         FIG. 6  is a flowchart of a method of wireless communication according to some embodiments. 
         FIG. 7  is a conceptual data flow diagram illustrating the data flow between different means/components according to some embodiments. 
         FIG. 8  is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system according to some embodiments. 
         FIG. 9  is a flowchart of a method of wireless communication according to some embodiments. 
         FIG. 10  is a conceptual data flow diagram illustrating the data flow between different means/components according to some embodiments. 
         FIG. 11  is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts. 
     In a carrier aggregation or EN-DC scenario, there exist multiple different conditions based on which UE would benefit from a higher or lower grant ratio on a specific carrier as opposed to other carriers. For example, the UE would benefit from indicating a preferred (or non-preferred) carrier to the serving base station. The base station, in turn, could adjust the rate at which uplink grants for the preferred (or non-preferred) carrier is provided to the UE. Furthermore, the preferred (and non-preferred) carrier for a UE may change dynamically based on changing radio conditions. 
     There are a number of criteria based on which UE may select a preferred carrier for uplink grant reception. Some example criteria explained below include self-jamming conditions, thermal constraints, and inter-RAT interference. These are not the only criteria envisioned as possible bases for identifying preferred carriers, non-preferred carriers, or ranking carriers. Various embodiments described below provide techniques for a UE to indicate preferred and non-preferred carriers to a serving base station. A serving base station, in turn, can make use of the indication to adjust the ratio at which uplink transmissions are scheduled on these carriers. 
     Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. 
     By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. 
     Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer. 
       FIG. 1  is a diagram illustrating an example of a wireless communications system and an access network  100 . The wireless communications system (also referred to as a wireless wide area network (WWAN)) includes base stations  102 , UEs  104 , and an Evolved Packet Core (EPC)  160 . The base stations  102  may include macro cells (high power cellular base station) and/or small cells (low power cellular base station). The macro cells include base stations. The small cells include femtocells, picocells, and microcells. 
     The base stations  102  (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) interface with the EPC  160  through backhaul links  132  (e.g., S 1  interface). In addition to other functions, the base stations  102  may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations  102  may communicate directly or indirectly (e.g., through the EPC  160 ) with each other over backhaul links  134  (e.g., X2 interface). The backhaul links  134  may be wired or wireless. 
     The base stations  102  may wirelessly communicate with the UEs  104 . Each of the base stations  102  may provide communication coverage for a respective geographic coverage area  110 . There may be overlapping geographic coverage areas  110 . For example, the small cell  102 ′ may have a coverage area  110 ′ that overlaps the coverage area  110  of one or more macro base stations  102 . A network that includes both small cell and macro cells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG). The communication links  120  between the base stations  102  and the UEs  104  may include uplink (UL) (also referred to as reverse link) transmissions from a UE  104  to a base station  102  and/or downlink (DL) (also referred to as forward link) transmissions from a base station  102  to a UE  104 . The communication links  120  may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations  102 /UEs  104  may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100 MHz) bandwidth per carrier allocated in a carrier aggregation (CA) of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or less carriers may be allocated for DL than for UL). The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell). 
     Certain UEs  104  may communicate with each other using device-to-device (D2D) communication link  192 . The D2D communication link  192  may use the DL/UL WWAN spectrum. The D2D communication link  192  may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication may be through a variety of wireless D2D communications systems, such as for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR. The wireless communications system may further include a Wi-Fi access point (AP)  150  in communication with Wi-Fi stations (STAs)  152  via communication links  154  in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs  152 /AP  150  may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available. 
     The small cell  102 ′ may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell  102 ′ may employ NR and use the same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP  150 . The small cell  102 ′, employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network. 
     The gNodeB (gNB)  180  may operate in millimeter wave (mmW) frequencies and/or near mmW frequencies in communication with the UE  104 . When the gNB  180  operates in mmW or near mmW frequencies, the gNB  180  may be referred to as an mmW base station. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in the band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmW/near mmW radio frequency band has extremely high path loss and a short range. The mmW base station  180  may utilize beamforming  184  with the UE  104  to compensate for the extremely high path loss and short range. 
     The EPC  160  may include a Mobility Management Entity (MME)  162 , other MMEs  164 , a Serving Gateway  166 , a Multimedia Broadcast Multicast Service (MBMS) Gateway  168 , a Broadcast Multicast Service Center (BM-SC)  170 , and a Packet Data Network (PDN) Gateway  172 . The MME  162  may be in communication with a Home Subscriber Server (HSS)  174 . The MME  162  is the control node that processes the signaling between the UEs  104  and the EPC  160 . Generally, the MME  162  provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway  166 , which itself is connected to the PDN Gateway  172 . The PDN Gateway  172  provides UE IP address allocation as well as other functions. The PDN Gateway  172  and the BM-SC  170  are connected to the IP Services  176 . The IP Services  176  may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, and/or other IP services. The BM-SC  170  may provide functions for MBMS user service provisioning and delivery. The BM-SC  170  may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway  168  may be used to distribute MBMS traffic to the base stations  102  belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information. 
     The base station may also be referred to as a gNB, Node B, evolved Node B (eNB), an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), or some other suitable terminology. The base station  102  provides an access point to the EPC  160  for a UE  104 . Examples of UEs  104  include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a prosthetic, medical device, entertainment device, industrial equipment, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a display, or any other similar functioning device. Some of the UEs  104  may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc.). The UE  104  may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. 
     Referring again to  FIG. 1 , in certain aspects, the UE  104  may be configured to communicate preferred and non-preferred carriers to base station  102 . Base station  102  may be configured to schedule uplink transmissions for UE  104  based on the preferred and non-preferred carriers. 
       FIG. 2  is a block diagram of a base station  210  in communication with a UE  250  in an access network. In the DL, IP packets from the EPC  160  may be provided to a controller/processor  275 . The controller/processor  375  implements layer  3  and layer  2  functionality. Layer  3  includes a radio resource control (RRC) layer, and layer  2  includes a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor  275  provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression/decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. 
     The transmit (TX) processor  216  and the receive (RX) processor  370  implement layer  1  functionality associated with various signal processing functions. Layer  1 , which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The TX processor  216  handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator  274  may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE  250 . Each spatial stream may then be provided to a different antenna  220  via a separate transmitter  218 TX. Each transmitter  218 TX may modulate an RF carrier with a respective spatial stream for transmission. 
     At the UE  250 , each receiver  254 RX receives a signal through its respective antenna  252 . Each receiver  254 RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor  256 . The TX processor  268  and the RX processor  256  implement layer  1  functionality associated with various signal processing functions. The RX processor  256  may perform spatial processing on the information to recover any spatial streams destined for the UE  250 . If multiple spatial streams are destined for the UE  250 , they may be combined by the RX processor  256  into a single OFDM symbol stream. The RX processor  256  then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station  210 . These soft decisions may be based on channel estimates computed by the channel estimator  258 . The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station  210  on the physical channel. The data and control signals are then provided to the controller/processor  259 , which implements layer  2  and layer  2  functionality. 
     The controller/processor  259  can be associated with a memory  260  that stores program codes and data. The memory  260  may be referred to as a computer-readable medium. In the UL, the controller/processor  259  provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC  160 . The controller/processor  259  is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations. 
     Similar to the functionality described in connection with the DL transmission by the base station  210 , the controller/processor  259  provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression/decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. 
     Channel estimates derived by a channel estimator  258  from a reference signal or feedback transmitted by the base station  210  may be used by the TX processor  268  to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor  268  may be provided to different antenna  252  via separate transmitters  254 TX. Each transmitter  254 TX may modulate an RF carrier with a respective spatial stream for transmission. 
     The UL transmission is processed at the base station  210  in a manner similar to that described in connection with the receiver function at the UE  250 . Each receiver  218 RX receives a signal through its respective antenna  220 . Each receiver  218 RX recovers information modulated onto an RF carrier and provides the information to a RX processor  270 . 
     The controller/processor  275  can be associated with a memory  276  that stores program codes and data. The memory  276  may be referred to as a computer-readable medium. In the UL, the controller/processor  275  provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE  250 . IP packets from the controller/processor  275  may be provided to the EPC  160 . The controller/processor  275  is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations. 
     Various wireless communication technologies may have a different frame structure and/or different channels. A frame may be divided into multiple (e.g.,  10 ) equally sized subframes. Each subframe may include multiple consecutive time slots (based on the type of numerology). A resource grid may be used to represent time slots, each time slot may include one or more time concurrent resource blocks (RBs) (also referred to as physical RBs (PRBs)). The resource grid is divided into multiple resource elements (REs). For a normal cyclic prefix, an RB may contain consecutive subcarriers in the frequency domain and consecutive symbols. The number of bits carried by each RE depends on the modulation scheme. 
     Some of the REs may carry reference (pilot) signals (RS) for downlink channel estimation at the UE. These RS may include cell-specific reference signals (CRS) (also sometimes called common RS), UE-specific reference signals (UE-RS), and channel state information reference signals (CSI-RS). 
     Various channels may exist within a DL subframe. The PDCCH carries downlink control information (DCI) within one or more control channel elements (CCEs), each CCE including multiple RE groups (REGs), each REG including a number of consecutive REs in an OFDM symbol. A UE may be configured with a UE-specific enhanced PDCCH (ePDCCH) that also carries DCI. The physical hybrid automatic repeat request (ARQ) (HARQ) indicator channel (PHICH) carries the HARQ indicator (HI) that indicates HARQ acknowledgement (ACK)/negative ACK (NACK) feedback based on the success of decoding a physical uplink shared channel (PUSCH). A primary synchronization signal (PSS) may serve to determine subframe/symbol timing and a physical layer identity. A secondary synchronization signal (SSS) that is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the locations of the downlink RS. A physical broadcast channel (PBCH), carries a master information block (MIB). The PBCH may be logically grouped with the PSS and SSS to form a synchronization signal (SS) block. The MIB provides system configuration information, including a number of RBs in the DL system bandwidth, a PHICH configuration, and a system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs), and paging messages. 
     Uplink subframes may include REs that carry demodulation reference signals (DM-RS) for channel estimation at the base station. The UE may additionally transmit sounding reference signals (SRS) in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL. 
     A physical random access channel (PRACH) may be within one or more subframes within a frame based on the PRACH configuration. The PRACH may include consecutive RB pairs within a subframe. The PRACH allows the UE to perform initial system access and achieve UL synchronization. A physical uplink control channel (PUCCH) may be located on edges of the UL system bandwidth. The PUCCH carries uplink control information (UCI), such as scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and HARQ ACK/NACK feedback. The PUSCH carries data and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and/or UCI. 
     To obtain an uplink grant from a base station, a UE sends an SR to the base station, e.g., following a random access procedure. In response to the SR, the network may allocate a minimal grant for the UE to send a BSR. The BSR indicates how much buffered data is pending uplink transmission at the UE. The BSR indicates the amount of buffered data using different quantized granularities (e.g., using an index). In response to the BSR, the base station may determine and transmit a suitable grant of uplink resources to the UE. 
     5G NR supports different types of carrier aggregation. Carrier aggregation is supported within frequency range 1 (FR 1 ) (e.g., sub 6 GHz), within frequency range 2 (FR 2 ) (e.g., mmWave), or as a combination of FR 1  and FR 2  (e.g., carrier aggregation with Sub 6 Ghz and mmWave carriers). Furthermore, 5G NR also supports EN-DC (EUTRA-NR Dual Connectivity) with at least one carrier on an LTE RAT and at least one carrier on a 5G NR RAT. 
     With respect to carrier aggregation, the BSR presents a limitation, as buffered data is not indicated per carrier, but as a single value per UE. Accordingly, the UE can indicate the amount of total data pending uplink transmission, but there is no mechanism to identify a preferred carrier from the UE side for the pending data. As such, a UE has no mechanism to specify a carrier on which it would prefer to receive a grant. Instead, the network selects to provide a grant on any of the active carriers. 
     Most networks employ a combination of CQI reporting from multiple carriers, load balancing, and other scheduling algorithms to determine the carrier on which to provide an uplink grant to the user or the proportions in which grants are distributed across multiple carriers. However, there exist multiple different scenarios and conditions based on which UE would benefit from a higher or lower grant ratio on a specific carrier as opposed to other carriers. In an ideal scenario, the UE could indicate a preferred (or non-preferred) carrier to the serving base station. The base station, in turn, could adjust the rate at which uplink grants for the preferred (or non-preferred) carrier are provided to the UE. Furthermore, the preferred (or non-preferred) carrier for a UE may change dynamically based on radio conditions. 
     There are a number of criteria based on which UE may prefer a specific carrier for uplink grant reception. Some example criteria explained below include self-jamming conditions, thermal constraints, and inter-RAT interference. These are not the only criteria envisioned as possible bases for identifying preferred carriers, non-preferred carriers, or ranking carriers. The detailed description set forth below in connection with these criteria is not intended to represent the only basis in which the invention may be practiced. The detailed description includes example criteria to provide a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that other criteria may be applied within the scope of the invention. 
     A first example criterion for identifying preferred carriers, non-preferred carriers, or ranking carriers includes self-jamming and similar interference conditions. In carrier aggregation or EN-DC scenarios, multiple carriers may be actively transmitting or receiving transmission on multiple transceivers. Transmission from one or more uplink carriers could cause self-interference to one of the active downlink carriers. The extent of the self-interference may depend on the in-device isolation between an aggressor transmitter and a victim receiver. The in-device isolation may refer to, for example, the extent to which harmonic or inter-modulation interference from an aggressor transmitter impacts a victim receiver. 
     In this example, the active uplink carrier causing the least interference to any active receiver would be a preferred carrier and any active uplink carrier which causes the most interference to any active receiver would be the non-preferred carrier. Where there is more than one aggressor transmitter, identifying the preferred (or non-preferred) carrier includes quantifying the interference or self-jamming that is caused to the respective receivers to a metric. This metric may be, for example, SNR-based. A preferred uplink carrier would be the uplink carrier associated with an aggressor transmitter causing the lowest magnitude of self-interference to any victim receiver, subject to a priority metric of the victim. For example, the measurement ranking of the uplink carrier may be based on a magnitude of interference caused to each victim receiver adjusted based on the properties of the receiver. The properties of the receiver may include whether the receiver is operating on a primary carrier or a secondary carrier, whether the victim receiver is idle or associated with a voice session. For example, each victim receiver may be given a priority indicator—a voice receiver has a higher priority than idle receiver for mobile terminated paging, which in turn has a higher priority than data receiver. The magnitude of the interference may be determined, for example, based on a delta between SNR under normal conditions and SNR under self-jamming or interference conditions. 
     A second example criterion for identifying preferred carriers, non-preferred carrier, or ranking carriers includes thermal constraints. Thermal constraint handling is one of the major concerns in 5G. In a scenario with multiple active uplink carriers, different uplink carriers may be active on different power amplifiers (PA) (for Sub 6 GHz) or different beamers/phasors (for mmW). A thermal (e.g., temperature) metric of each carrier may serve to determine the carrier contributing the most and least to the overall system thermal conditions. The thermal metric may be based on a thermistor reading from different phasors or PAs in a device. For example, a carrier associated with a highest transmit power and thermistor reading may have a greater impact on the overall temperature of the system and would correspond to a non-preferred carrier. Similarly, the carrier with the lowest thermal contribution to the device temperature would be the most preferred carrier. By reducing the ratio of uplink grants on the non-preferred carrier and increasing the ratio of uplink grants on the most preferred carrier, the system could improve the duty cycle of the transmitter components (e.g., PA, phasors, beamers) by allowing them sufficient time to cool down and thereby controlling the temperature of the device. 
     In an embodiment, the thermal constraints may be determined based on a comparison of active PA thermal readings and average PA thermal readings. For each carrier, the device may track the average transmit power and thermal readings for a last N subframes, and compare a current thermistor reading for active PA/beamer with the average reading. The carrier associated with the PA/phasors with the highest thermistor reading relative to the average reading (beyond a hysteresis) may correspond to a non-preferred carrier (where the hysteresis serves to prevent minor temperature variation from arbitrarily impacting the carrier preference). In response to the preferred carrier indication, the network can respond by providing a thinner grant ratio on the indicated carrier, thereby allowing the PA to go to a lower power mode and cool down. 
     A third example criterion for identifying preferred carriers, non-preferred carriers, or ranking carriers includes jamming of non-WAN communications (e.g., GNSS). There are scenarios in which the active carrier transmission on 5G NR may jam non-WAN technologies. For example, jamming of GNSS reception is a common scenario. 
     The present solution for GNSS jamming is to blank GNSS transmissions to the UE when the aggressor is active or perform a power back-off of the aggressor transmission. “Blanking” refers to the practice of modifying the active receiver side such that up to 80% of GNSS subframes are received while there is no active aggressor in the system. However, this extends the sampling period of the GNSS receiver. These solutions suffer from different limitations. For example, with blanking, if an aggressor transmitter is continuously active, excessive blanking may cause GNSS decode failures and poor position fixes. Similarly, power back-off to the aggressor transmit power can cause RLF on cell edge scenarios or power headroom reduction. Both of these limitations can be overcome by indicating a preferred carrier, which is not an aggressor to the active GNSS, and indicating any active aggressor to the GNSS as the non-preferred carrier. Such an approach allocates the thinnest grant ratio to the non-preferred carrier (GNSS aggressor in this example), and thereby allows sufficient non-jamming time to GNSS to perform decodes. 
     The UE may benefit from a mechanism to indicate a carrier preference to the base station. In one example, an enhanced BSR format may be added that includes fields for signaling one or more carriers to the base station. The base station may indicate to use this enhanced BSR format by providing the UE with a corresponding LCID value.  FIG. 3  illustrates a table  300  of LCID values supported by 5G NR. At present, 5G NR supports LCID values for various BSR formats (e.g., short BSR, long BSR, short truncated BSR, long truncated BSR, and padding BSR). The LCID table  300  includes reserved values  305  to support future LCID values. Accordingly, one or more new BSR formats may be associated with a reserved LCID value. For example, a new enhanced BSR associated with LCID value  33  may be added, which includes support for transmission of one or more carrier ID values. 
     In one example, a new enhanced BSR format may include an additional octet that is defined to include two 4-bit carrier ID values.  FIG. 4  illustrates an example BSR format  400  that includes bit indicators for logical channel groups (LCGs)  0 - 7 , an octet  415  for supporting two 4-bit carrier IDs  405 ,  410 , and Octets  2  to m+1 (where m&lt;8) for indicating buffer sizes  1  to m corresponding to the LCG&#39;s indicated as present in Octet  1  of the BSR. Buffer sizes  1  to m correspond to index values associated with corresponding buffer sizes of pending uplink data for each of LCG  0 - 7  indicated as present in Octet  1  of the BSR. The 4 least significant bits  410  may specify a preferred carrier ID, and the 4 most significant bits  405  may specify the non-preferred carrier ID. The 4-bit values allow for 16 possible carrier IDs each. In a variation of the example, to support up to 32 carriers, an entire or portion of a first octet can be reserved to indicate a preferred carrier ID, and an entire or portion of a second octet can be reserved to indicate a non-preferred carrier ID. 
     In another embodiment, in addition to specifying the preferred carrier and non-preferred carrier, the UE may provide the base station with a ranked list of carriers in order of preference for uplink grants. Given the size of such a communication, this list may be provided via RRC signaling on a periodic basis. This ranking may be regularly updated with BSR transmissions indicating the preferred carriers and/or non-preferred carriers. 
     In another embodiment, a MAC-CE may be defined to communicate carrier preferences for uplink grants. As the UE radio condition changes, the MAC-CE can be used to update the UE&#39;s preference as well. Such a MAC-CE may be configured as part of a periodic transmission in place of, or in addition to, BSR or RRC carrier indications. 
     The proposed embodiment may further and indirectly provide indications for DTX on a specific carrier. That is, by indicating a non-preferred carrier, the UE may request to initiate DTX on the non-preferred carrier. In another embodiment, an additional UE signaling, or a MAC-CE can be added for a UE to request DTX on a specific carrier for a specific time. Thereby, the UE may provide DTX preferences to the base station based on, for example, thermal, maximum permissible exposure (MPE), interference control, and other UE specific control procedures. 
     The above embodiment and example provide a UE with additional capability to increase the uplink grant ratio on its preferred active carrier. This may allow the UE to improve performance relative to a device without the ability to adjust carrier ratios under the same network conditions. In this way, various UE specific impairments can be effectively overcome without the need for additional HW, while increasing processing capabilities. 
       FIG. 5  is a diagram  500  illustrating a base station  504  in communication with a UE  502  according to some embodiments. The diagram  500  illustrates a process by which a UE  502  may identify and communicate a preferred and/or non-preferred uplink carrier to a base station. The UE  502  may be configured to operate using a plurality of carriers. For example, the UE  502  may be configured to use carrier aggregation or EN-DC. 
     At  505 , the UE  502  may provide base station  504  with a capability indication. The capability indication may indicate that the UE  502  supports an ability to identify and transmit an indication of the preferred and/or non-preferred uplink carrier to a base station. This indication may be, for example, an indication of a UE category that supports such measurement and indication. Alternatively, the indication may be indicated via RRC or MAC signaling. Alternatively, the UE may indicate such support during a random-access procedure. Furthermore, the capability may be indicated as part of an SR transmitted to the base station. 
     At  510 , the UE  502  may transmit an SR to base station  504 . The SR indicates to base station  504  that UE  502  has buffered data for transmission to the base station  504 . 
     At  515 , the base station  504  may transmit a signal to the UE  502  to transmit a BSR. The indication may include a BSR format that the UE  502  should send to the base station. The indicated BSR format may be an enhanced BSR format with fields for indicating a preferred carrier and/or a non-preferred carrier. The carrier indication in the BSR format may include two 4-bit fields for indicating the preferred carrier and non-preferred carrier, or may include one or more 8-bit fields for indicating the preferred and/or non-preferred carrier. 
     At  520 , the UE  502  may measure carrier quality. Step  520  may be performed on a continual basis at the UE, whereby the UE  502  continually monitors carrier quality. Alternatively, the UE  502  may measure carrier quality periodically or in response to certain base station communications, such as receipt of a grant to transmit BSR, or in response to internal conditions (e.g., having buffered data for uplink). Carrier quality may be measured based on one of more UE  502  conditions. As discussed above, these conditions may include, for example, self-jamming between downlink and uplink transmissions, thermal conditions impacting specific carrier and/or transmit chains, and non-WWAN interference. In one embodiment, the UE  502  may rank or prioritize the configured plurality of uplink carriers. 
     A  525 , the UE  502  may determine a preferred carrier from among a plurality of carriers as set forth above. 
     At  530 , the UE  502  may determine a non-preferred carrier from among a plurality of carriers which it is configured to use. Various measurable UE conditions may form the basis for selecting a non-preferred carrier. 
     Steps  520 ,  525 , and  530  may be performed sequentially or may be performed as a combined step. Accordingly, the UE  502  may rank the carriers and thereby identify the preferred and non-preferred carriers based on the carrier rankings. 
     At  535 , UE  502  may transmit a BSR to the base station  504 . The BSR may be an enhanced BSR indicating the preferred carrier and/or the non-preferred carrier. As illustrated in  FIG. 4 , the carrier indication in the BSR may include two 4-bit fields for indicating the preferred carrier and non-preferred carrier or may include one or more 8-bit fields for indicating the preferred and/or non-preferred carrier. 
     Alternatively, the UE  502  may indicate the preferred carrier and/or non-preferred carrier via MAC or RRC signaling. The MAC signaling may include transmission of a MAC-CE including fields for the preferred carrier and/or non-preferred carrier, and may be transmitted periodically or aperiodically (e.g., based on a request from the base station). RRC signaling providing carrier preferences may include the preferred carrier and/or non-preferred carrier or may include a ranked list of a plurality of carriers. RRC signaling may also be transmitted periodically or aperiodically. 
     At  540 , the base station  504  may schedule an uplink grant. The uplink grant may be a cross-carrier grant or a self-scheduling grant (depending on the carrier configuration). The base station  540  may schedule the uplink grant for a specific carrier based in-part or in-whole on the preferred carrier and/or non-preferred carrier indication(s) from UE  502 . Additionally, the base station may schedule the UE based on measured CQI, network load, QoS requirements, the requirements of other UEs and other network conditions conventionally associated with carrier schedule criteria. 
     At  545 , the base station  504  may transmit an uplink grant to UE  502 . The grant may indicate the carrier and resource allocation for transmission of the buffered data. The indicated carrier may correspond to the preferred carrier, or not correspond to the non-preferred carrier. 
     At  550 , the UE  550  may transmit all or a portion of the buffered data to the base station  504  based on the carrier and resource allocation provided in the uplink grant. 
     Additionally (not shown), the base station  504  may modify the DTX configuration of a UE  502  based on the indication of the non-preferred carrier. For example, the base station  504  may deactivate transmission chains associated with the non-preferred carriers. 
       FIG. 6  is a flowchart  900  of a method of wireless communication. The method may be performed by a UE (e.g., the UE  104 ,  502 , the apparatus  802 / 802 ′). The method covers a process by which a UE may indicate a preferred carrier for uplink transmission to a base station. The indication may be provided in a BSR, MAC-CE, or RRC communication. In response, the base station may adjust its criteria when selecting a carrier for subsequent uplink transmissions. In flowchart  600 , dashed lines represent optional steps. 
     At  605 , the UE may receive a BSR format from the base station. The BSR format may correspond to an enhanced BSR format, with a field to identify one or more carriers to the base station. The base station may indicate for the UE to use this enhanced BSR format by providing the UE with a corresponding LCID value. The new BSR format may include an octet that is defined to include two 4-bit carrier ID values. Alternatively, an entire or a portion of an octet can be reserved to indicate UE&#39;s most preferred carrier ID, and an entire or portion of a second octet can be reserved to indicate UE&#39;s non-preferred carrier ID. 
     At  610 , the UE may measure carrier quality. A UE configured to employ carrier aggregation or EN-DC may measure carrier quality over a plurality of uplink configured carriers. Carrier quality may be determined based on one of more UE measurable conditions. As discussed above, these conditions may include, for example, self-jamming between downlink and uplink transmissions, thermal conditions impacting specific carrier and/or transmit chains, and non-WWAN interference. In one embodiment, the UE  502  may rank or prioritize the configured uplink carriers. 
     At  615 , the UE may identify a first carrier corresponding to a first measured carrier quality. The first carrier may have a corresponding first measured carrier quality. In one example, the first carrier may be a preferred carrier from among a plurality of carriers. Various measurable UE conditions may form the basis for selecting a preferred carrier. In another example, the carrier may be a non-preferred carrier. 
     At  620 , the UE may identify a second carrier corresponding to a second carrier quality. The second carrier may be one of the plurality of carriers. The second carrier may be selected based on a second measured carrier quality. In one example, the first measured carrier quality may be a highest measured carrier quality associated with the plurality carriers, and the second measured carrier quality may be a lowest measured carrier quality associated with the plurality carriers. 
     In a first example, the measured carrier quality may correspond to self-interference within the UE. Self-interference may correspond to interference within the UE or to one or more downlink carriers caused by uplink carrier transmissions from the UE. That is, a transmit chain configured to transmit on one carrier may cause interference to a receive chain for another carrier. In this scenario, the measured carrier quality may be based on the magnitude of the self-interference to the downlink carrier that is the victim of the interference. The first carrier corresponds to an uplink carrier that causes the least amount of measurable self-interference. 
     In a second example, the measured carrier quality may correspond to a thermal metric associated with transmission on one or more uplink carriers. The thermal metric may be based on a transmit power and/or a thermal measurement associated with transmission on the one or more uplink carriers. For example, the thermal measurement may be a thermistor reading of a PA or phaser used for uplink transmission. In this example, the first carrier corresponds to an uplink carrier associated with a transmit chain having the lowest thermal metric. Similarly, the second carrier corresponds to an uplink carrier associated with a transmit chain having the highest thermal metric. 
     In a third example, the UE employs a non-WWAN network, and the carrier quality is based on interference experienced by a non-WWAN system (e.g., GNSS) due to uplink communications. 
     At  625 , the UE may send an uplink transmission with a carrier indication. The uplink transmission may be a BSR. BSR may have a format including a first carrier indicator field and a second carrier indicator field. Alternatively and as discussed above, the uplink transmission may include a MAC control element (CE) or RRC parameter having the first carrier indicator and the second carrier indicator. 
     Finally, at  630 , the UE may receive an uplink grant. The uplink grant indicates the carrier and resources on which the UE may transmit buffered data. 
     At  635 , the UE may additionally receive a DTX configuration. The DTX configuration may provide indications for DTX on a specific carrier. That is, the base station may indicate to the UE to initiate DTX on the non-preferred carrier. In another embodiment, additional UE signaling (e.g., a MAC-CE) can be introduced for a UE to request DTX on a carrier. Thereby, the UE may use the preferred and non-preferred carrier indication to provide DTX preferences to the base station based on, for example, thermal, MPE, interference control and other UE conditions. As such, the base station may provide a mechanism by which the UE may indicate over-heated transmit chains (e.g., including heavily active mmWave phasers) to the base station, and the base station may use DTX to allow those receive chains to cool down. 
       FIG. 7  is a conceptual data flow diagram  700  illustrating the data flow between different means/components in an exemplary apparatus  702 . The apparatus may be a UE. The apparatus includes RF component  704 , carrier quality measurement component  706 , buffer monitoring component  708 , BSR generator  710 , DTX component  712 , and uplink transmission component  714 . RF component  704  receives downlink transmission  716  from base station  750  and transmits uplink transmissions  734  to base station  750 . Downlink transmissions  716  include various signaling from base station  750 , including reference signals, control information (e.g., uplink grants), and data. Uplink transmission  724  may include reference signals, control information (e.g., BSR, MAC-CE), and buffered data. Carrier quality measurement component  706  may receive and measure carrier quality from measurable signals  718  (e.g., reference signals, broadcast signals) received by RF component  704 . Buffer monitoring component  708  monitors the quantity of data for uplink transmission at apparatus  702 . BSR generator  710  generates a BSR  726  for transmission to base station  750  based on buffer data information  724  and carrier quality preferences/measurements  722 . DTX component  712  may receive a DTX configuration  728  from base station  750 . Uplink transmission component  714  processes uplink grants  730  from base station  750 , and provides uplink data  732  for transmission to base station  750 . 
     The apparatus may include additional components that perform each of the blocks of the algorithm in the aforementioned flowcharts of  FIGS. 5 and 6 . As such, each block in the aforementioned flowcharts of  FIG. 6  may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof. 
       FIG. 8  is a diagram  800  illustrating an example of a hardware implementation for an apparatus  702 ′ employing a processing system  814 . The processing system  814  may be implemented with a bus architecture, represented generally by the bus  824 . The bus  824  may include any number of interconnecting buses and bridges depending on the specific application of the processing system  814  and the overall design constraints. The bus  824  links together various circuits including one or more processors and/or hardware components, represented by the processor  804 , the components  704 ,  706 ,  708 ,  710 ,  712 , and  74  and the computer-readable medium/memory  806 . The bus  824  may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. 
     The processing system  814  may be coupled to a transceiver  810 . The transceiver  810  is coupled to one or more antennas  820 . The transceiver  810  provides a means for communicating with various other apparatus over a transmission medium. The transceiver  810  receives a signal from the one or more antennas  820 , extracts information from the received signal, and provides the extracted information to the processing system  814 , specifically the RF component  704 . In addition, the transceiver  810  receives information from the processing system  814 , specifically the RF component  704 , and based on the received information, generates a signal to be applied to the one or more antennas  820 . The processing system  814  includes a processor  804  coupled to a computer-readable medium/memory  806 . The processor  804  is responsible for general processing, including the execution of software stored on the computer-readable medium/memory  806 . The software, when executed by the processor  804 , causes the processing system  814  to perform the various functions described supra for any particular apparatus. The computer-readable medium/memory  806  may also be used for storing data that is manipulated by the processor  804  when executing software. The processing system  814  further includes at least one of the components  704 ,  706 ,  708 . The components may be software components running in the processor  804 , resident/stored in the computer readable medium/memory  806 , one or more hardware components coupled to the processor  804 , or some combination thereof. The processing system  814  may be a component of the UE  250  and may include the memory  260  and/or at least one of the TX processor  268 , the RX processor  256 , and the controller/processor  259 . 
     In one configuration, the apparatus  702 / 702 ′ for wireless communication includes means for means measuring carrier quality on a plurality of carriers, means for identifying a first carrier from the plurality of carriers, the first carrier corresponding to a first measured carrier quality, means for sending an uplink transmission to a base station, the uplink transmission including an indication of the first carrier, means for receiving an uplink grant from the base station based on the uplink transmission. The aforementioned means may be one or more of the aforementioned components of the apparatus  702  and/or the processing system  814  of the apparatus  702 ′ configured to perform the functions recited by the aforementioned means. As described supra, the processing system  814  may include the TX Processor  268 , the RX Processor  256 , and the controller/processor  259 . As such, in one configuration, the aforementioned means may be the TX Processor  268 , the RX Processor  256 , and the controller/processor  259  configured to perform the functions recited by the aforementioned means. 
       FIG. 9  is a flowchart  900  of a method of wireless communication. The method may be performed by a base station (e.g., the base station  102 ,  504 , or the apparatus  1002 / 1002 ′). The method covers a process by which a base station receives a preferred carrier indication from a UE. The indication may be provided via a BSR, MAC-CE, or RRC communication. In response, the base station may adjust its criteria when selecting a carrier for subsequent uplink transmissions. In flowchart  900 , dashed lines represent optional steps. 
     At  902 , the base station may transmit an indication of a BSR format. The BSR format may correspond to an enhanced BSR format, with a field to identify one or more carriers to the base station. The base station may indicate for the UE to use this enhanced BSR format by providing the UE with a corresponding LCID value. The BSR format may be provided based on a determined UE capability. For example, the UE may indicate the ability to support the enhanced BSR by indicating a UE category or by providing MAC or RRC communications indicative of supporting an enhanced BSR. 
     At  904 , the base station may receive an uplink transmission, including a first carrier indicator. The first indicator may correspond to a first measured carrier quality. The first measured carrier quality may correspond to a highest measured carrier quality or lowest measured carrier quality. The uplink transmission may also include a second carrier indicator corresponding to a second measured carrier quality, in which case the first measured carrier quality may be a highest measured carrier quality, and the second measured carrier quality may be a lowest measured carrier quality. The uplink transmission may be a BSR (e.g., the enhanced BSR), a MAC control element (CE), or RRC signaling. 
     At  906 , the base station may schedule at least one uplink transmission. Scheduling the uplink transmissions may be based on the first carrier indicator. For example, the base station may adjust a rate of uplink grants scheduled on the first carrier based on the first measured carrier quality. For example, if the first carrier indicator corresponds to a preferred carrier, the base station may increase the ratio of uplink grants on the first carrier. Conversely, if the first carrier indicator corresponds to a non-preferred carrier, the base station may decrease the ratio of uplink grants on the first carrier or not schedule transmissions on the carrier. If the uplink transmission includes both a first carrier indicator associated with a preferred carrier and a second carrier indicator associated with a non-preferred carrier, the base station may increase the grant ratio of uplink grants on the first carrier and decrease the ratio of uplink grants on the second carrier. 
     Finally, at  908 , the base station may transmit an uplink grant to the UE. 
     At  910 , the base station may also transmit a DTX configuration to the UE. The DTX configuration may correspond to the first carrier and second carrier based on the information conveyed by the first carrier indicator and the second carrier indicator. The DTX configuration may provide for DTX on a specific carrier. That is, the base station may indicate to the UE to initiate DTX on the non-preferred carrier. As such, the base station may provide a mechanism by which an over-heated transmit chain (e.g., including active mmWave phasers) may use DTX to cool down. 
       FIG. 10  is a conceptual data flow diagram  1000  illustrating the data flow between different means/components in an exemplary apparatus  1002 . The apparatus may be a base station. The apparatus includes RF component  1004 , scheduler component  1006 , DTX component  1008 , and BSR format selector  1010 . RF component  1004  transmits downlink transmissions  1022  to UE  1050  and receives uplink transmissions  1012  from UE  1050 . Downlink transmissions  1022  include various signaling, including reference signals, control information (e.g., uplink Grants), and data. Uplink transmission  1012  reference signals, control information (e.g., BSR, MAC-CE), and buffered data. Scheduler  1006  receives scheduling control information  1014  (e.g., CQI measurement, BSR) generates downlink assignments and uplink grants  1016  for UE  1050 . DTX components generate DTX configurations  1018  for UE  1050  based on UE parameters, including preferred and non-preferred carrier indication information. BSR Format Selector  1010  transmits an indicator  1020  to UE  1050  indicating the type of BSR to transmit to apparatus  1002 . 
     The apparatus may include additional components that perform each of the blocks of the algorithm in the aforementioned flowcharts of  FIGS. 5 and 9 . As such, each block in the aforementioned flowcharts of  FIG. 9  may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof. 
       FIG. 11  is a diagram  1100  illustrating an example of a hardware implementation for an apparatus  1002 ′ employing a processing system  1114 . The processing system  1114  may be implemented with a bus architecture, represented generally by the bus  1124 . The bus  1124  may include any number of interconnecting buses and bridges depending on the specific application of the processing system  1114  and the overall design constraints. The bus  1124  links together various circuits including one or more processors and/or hardware components, represented by the processor  1104 , the components  1004 ,  1006 ,  1008 ,  1010 , and the computer-readable medium/memory  1106 . The bus  1124  may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. 
     The processing system  1114  may be coupled to a transceiver  1110 . The transceiver  1110  is coupled to one or more antennas  1120 . The transceiver  1110  provides a means for communicating with various other apparatus over a transmission medium. The transceiver  1110  receives a signal from the one or more antennas  1120 , extracts information from the received signal, and provides the extracted information to the processing system  1114 . In addition, the transceiver  1110  receives information from the processing system  1114 , and based on the received information, generates a signal to be applied to the one or more antennas  1120 . The processing system  1114  includes a processor  1104  coupled to a computer-readable medium/memory  1106 . The processor  1104  is responsible for general processing, including the execution of software stored on the computer-readable medium/memory  1106 . The software, when executed by the processor  1104 , causes the processing system  1114  to perform the various functions described supra for any particular apparatus. The computer-readable medium/memory  1106  may also be used for storing data that is manipulated by the processor  1104  when executing software. The processing system  1114  further includes at least one of the components  1004 ,  1006 ,  1008 , and  1010 . The components may be software components running in the processor  1104 , resident/stored in the computer readable medium/memory  1106 , one or more hardware components coupled to the processor  1104 , or some combination thereof. (The processing system  1114  may be a component of the base station  210  and may include the memory  276  and/or at least one of the TX processor  216 , the RX processor  270 , and the controller/processor  275   
     In one configuration, the apparatus_ 1002 /_ 1002 ′ for wireless communication includes means for means for receiving an uplink transmission from a, the uplink transmission including a first carrier indicator, the first carrier indicator corresponding to a first measured carrier quality for a first carrier, means for scheduling uplink transmissions based on first carrier indicator, and means for transmitting an uplink grant from the base station based on the uplink transmission. The aforementioned means may be one or more of the aforementioned components of the apparatus_ 1002  and/or the processing system  1114  of the apparatus_ 1002 ′ configured to perform the functions recited by the aforementioned means. As described supra, the processing system  1114  may include the TX Processor  216 , the RX Processor  270 , and the controller/processor  275 . As such, in one configuration, the aforementioned means may be the TX Processor  216 , the RX Processor  270 , and the controller/processor  275  configured to perform the functions recited by the aforementioned means. 
     It is understood that the specific order or hierarchy of blocks in the processes/flowcharts disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes/flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented. 
     The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module,” “mechanism,” “element,” “device,” and the like may not be a substitute for the word “means.” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for.”