WO2021142561A1

WO2021142561A1 - Methods and apparatus for aperiodic srs triggering

Info

Publication number: WO2021142561A1
Application number: PCT/CN2020/071642
Authority: WO
Inventors: Alexandros MANOLAKOS; Wei Yang; Muhammad Sayed Khairy Abdelghaffar; Yi Huang; Yu Zhang; Wanshi Chen
Original assignee: Qualcomm Incorporated
Priority date: 2020-01-13
Filing date: 2020-01-13
Publication date: 2021-07-22

Abstract

The present disclosure relates to methods and devices for wireless communication including a UE and a base station. In some aspects, the base station can schedule for uplink transmissions on multiple component carriers (CCs). The base station can also transmit a downlink control information (DCI) on a first CC of the multiple CCs. The base station can also receive one or more aperiodic SRS resource sets on at least one third CC based on at least one of the DCI or an SRS configuration. The UE can receive scheduling for uplink transmissions on multiple CCs. The UE can also receive a DCI on a first CC of the multiple CCs. The UE can also transmit one or more aperiodic SRS resource sets on at least one third CC based on at least one of the DCI or an SRS configuration.

Description

METHODS AND APPARATUS FOR APERIODIC SRS TRIGGERING

BACKGROUND

Technical Field

The present disclosure relates generally to communication systems, and more particularly, to methods and apparatus related to sounding reference signal (SRS) in wireless communication systems.

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. Examples of such 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.

These 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. 5G NR includes services associated with enhanced mobile broadband (eMBB) , massive machine type communications (mMTC) , and ultra reliable low latency communications (URLLC) . 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.

SUMMARY

The following presents a simplified summary of one or more aspects in order 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. In some aspects, the apparatus may receive scheduling for uplink transmissions on multiple component carriers (CCs) . The apparatus can also receive a downlink control information (DCI) on a first CC of the multiple CCs, where the DCI includes a sounding reference signal (SRS) request field for the triggering of one or more aperiodic SRS resource sets. The apparatus can also transmit the one or more aperiodic SRS resource sets on at least one third CC based on at least one of the DCI or an SRS configuration.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a base station. In some aspects, the apparatus may schedule for uplink transmissions on multiple component carriers (CCs) . The apparatus can also transmit the scheduling for the uplink transmissions on the multiple CCs. The apparatus can also transmit a downlink control information (DCI) on a first CC of the multiple CCs, where the DCI includes a sounding reference signal (SRS) request field for the triggering of one or more aperiodic SRS resource sets. The apparatus can also receive the one or more aperiodic SRS resource sets on at least one third CC based on at least one of the DCI or an SRS configuration.

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.

FIGs. 2A, 2B, 2C, and 2D are diagrams illustrating examples of a first 5G/NR frame, DL channels within a 5G/NR subframe, a second 5G/NR frame, and UL channels within a 5G/NR subframe, respectively.

FIG. 3 is a diagram illustrating an example of a base station and user equipment (UE) in an access network.

FIG. 4 is a diagram illustrating an example of SRS triggering.

FIG. 5 is a diagram illustrating an example of SRS triggering.

FIG. 6 is a diagram illustrating an example of SRS triggering.

FIG. 7 is a diagram illustrating an example of SRS triggering.

FIG. 8 is a diagram illustrating an example of SRS triggering.

FIG. 9 is a diagram illustrating example communication between a UE and a base station.

FIG. 10 is a flowchart of a method of wireless communication.

FIG. 11 is a flowchart of a method of wireless communication.

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.

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, an Evolved Packet Core (EPC) 160, and another core network 190 (e.g., a 5G Core (5GC) ) . The base stations 102 may include macrocells (high power cellular base station) and/or small cells (low power cellular base station) . The macrocells include base stations. The small cells include femtocells, picocells, and microcells.

The base stations 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN) ) may interface with the EPC 160 through first backhaul links 132 (e.g., S1 interface) . The base stations 102 configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN) ) may interface with core network 190 through second backhaul links 184. 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 or core network 190) with each other over third backhaul links 134 (e.g., X2 interface) . The third 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 macrocells 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, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation 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 fewer 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 158. The D2D communication link 158 may use the DL/UL WWAN spectrum. The D2D communication link 158 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.

A base station 102, whether a small cell 102' or a large cell (e.g., macro base station) , may include and/or be referred to as an eNB, gNodeB (gNB) , or another type of base station. Some base stations, such as gNB 180 may operate in a traditional sub 6 GHz spectrum, 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 (e.g., 3 GHz –300 GHz) has extremely high path loss and a short range. The mmW base station 180 may utilize beamforming 182 with the UE 104 to compensate for the extremely high path loss and short range. The base station 180 and the UE 104 may each include a plurality of antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate the beamforming.

The base station 180 may transmit a beamformed signal to the UE 104 in one or more transmit directions 182'. The UE 104 may receive the beamformed signal from the base station 180 in one or more receive directions 182″. The UE 104 may also transmit a beamformed signal to the base station 180 in one or more transmit directions. The base station 180 may receive the beamformed signal from the UE 104 in one or more receive directions. The base station 180 /UE 104 may perform beam training to determine the best receive and transmit directions for each of the base station 180 /UE 104. The transmit and receive directions for the base station 180 may or may not be the same. The transmit and receive directions for the UE 104 may or may not be the same.

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 core network 190 may include a Access and Mobility Management Function (AMF) 192, other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. The AMF 192 may be in communication with a Unified Data Management (UDM) 196. The AMF 192 is the control node that processes the signaling between the UEs 104 and the core network 190. Generally, the AMF 192 provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF 195. The UPF 195 provides UE IP address allocation as well as other functions. The UPF 195 is connected to the IP Services 197. The IP Services 197 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and/or other IP services.

The base station may include and/or be referred to as a gNB, 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) , a transmit reception point (TRP) , or some other suitable terminology. The base station 102 provides an access point to the EPC 160 or core network 190 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 vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, 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 include a reception component 198 configured to receive scheduling for uplink transmissions on multiple component carriers (CCs) . Reception component 198 may also be configured to receive a downlink control information (DCI) on a first CC of the multiple CCs, where the DCI includes a sounding reference signal (SRS) request field for the triggering of one or more aperiodic SRS resource sets. Reception component 198 may also be configured to transmit the one or more aperiodic SRS resource sets on at least one third CC based on at least one of the DCI or an SRS configuration.

Referring again to FIG. 1, in certain aspects, the base station 180 may include a transmission component 199 configured to schedule for uplink transmissions on multiple component carriers (CCs) . Transmission component 199 may also be configured to transmit the scheduling for the uplink transmissions on the multiple CCs. Transmission component 199 may also be configured to transmit a downlink control information (DCI) on a first CC of the multiple CCs, where the DCI includes a sounding reference signal (SRS) request field for the triggering of one or more aperiodic SRS resource sets. Transmission component 199 may also be configured to receive the one or more aperiodic SRS resource sets on at least one third CC based on at least one of the DCI or an SRS configuration.

Although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

FIG. 2A is a diagram 200 illustrating an example of a first subframe within a 5G/NR frame structure. FIG. 2B is a diagram 230 illustrating an example of DL channels within a 5G/NR subframe. FIG. 2C is a diagram 250 illustrating an example of a second subframe within a 5G/NR frame structure. FIG. 2D is a diagram 280 illustrating an example of UL channels within a 5G/NR subframe. The 5G/NR frame structure may be FDD in which for a particular set of subcarriers (carrier system bandwidth) , subframes within the set of subcarriers are dedicated for either DL or UL, or may be TDD in which for a particular set of subcarriers (carrier system bandwidth) , subframes within the set of subcarriers are dedicated for both DL and UL. In the examples provided by FIGs. 2A, 2C, the 5G/NR frame structure is assumed to be TDD, with subframe 4 being configured with slot format 28 (with mostly DL) , where D is DL, U is UL, and X is flexible for use between DL/UL, and subframe 3 being configured with slot format 34 (with mostly UL) . While

subframes

3, 4 are shown with slot formats 34, 28, respectively, any particular subframe may be configured with any of the various available slot formats 0-61. Slot formats 0, 1 are all DL, UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. UEs are configured with the slot format (dynamically through DL control information (DCI) , or semi-statically/statically through radio resource control (RRC) signaling) through a received slot format indicator (SFI) . Note that the description infra applies also to a 5G/NR frame structure that is TDD.

Other wireless communication technologies may have a different frame structure and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms) . Each subframe may include one or more time slots. Subframes may also include mini-slots, which may include 7, 4, or 2 symbols. Each slot may include 7 or 14 symbols, depending on the slot configuration. For slot configuration 0, each slot may include 14 symbols, and for slot configuration 1, each slot may include 7 symbols. The symbols on DL may be cyclic prefix (CP) OFDM (CP-OFDM) symbols. The symbols on UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also referred to as single carrier frequency-division multiple access (SC-FDMA) symbols) (for power limited scenarios; limited to a single stream transmission) . The number of slots within a subframe is based on the slot configuration and the numerology. For slot configuration 0, different numerologies μ 0 to 5 allow for 1, 2, 4, 8, 16, and 32 slots, respectively, per subframe. For slot configuration 1, different numerologies 0 to 2 allow for 2, 4, and 8 slots, respectively, per subframe. Accordingly, for slot configuration 0 and numerology μ, there are 14 symbols/slot and 2 ^μ slots/subframe. The subcarrier spacing and symbol length/duration are a function of the numerology. The subcarrier spacing may be equal to 2 ^μ*15 kHz, where μ is the numerology 0 to 5. As such, the numerology μ=0 has a subcarrier spacing of 15 kHz and the numerology μ=5 has a subcarrier spacing of 480 kHz. The symbol length/duration is inversely related to the subcarrier spacing. FIGs. 2A-2D provide an example of slot configuration 0 with 14 symbols per slot and numerology μ=0 with 1 slot per subframe. The subcarrier spacing is 15 kHz and symbol duration is approximately 66.7 μs.

A resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs) ) that extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs) . The number of bits carried by each RE depends on the modulation scheme.

As illustrated in FIG. 2A, some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include demodulation RS (DM-RS) (indicated as R _x for one particular configuration, where 100x is the port number, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS) , beam refinement RS (BRRS) , and phase tracking RS (PT-RS) .

FIG. 2B illustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) , each CCE including nine RE groups (REGs) , each REG including four consecutive REs in an OFDM symbol. A primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE 104 to determine subframe/symbol timing and a physical layer identity. A secondary synchronization signal (SSS) may be within symbol 4 of particular subframes of a frame. The SSS 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 aforementioned DM-RS. The physical broadcast channel (PBCH) , which carries a master information block (MIB) , may be logically grouped with the PSS and SSS to form a synchronization signal (SS) /PBCH block. The MIB provides a number of RBs in the system bandwidth 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.

As illustrated in FIG. 2C, some of the REs carry DM-RS (indicated as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE may transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH) . The PUSCH DM-RS may be transmitted in the first one or two symbols of the PUSCH. The PUCCH DM-RS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used. The UE may transmit sounding reference signals (SRS) . The SRS may be transmitted 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.

FIG. 2D illustrates an example of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. 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.

FIG. 3 is a block diagram of a base station 310 in communication with a UE 350 in an access network. In the DL, IP packets from the EPC 160 may be provided to a controller/processor 375. 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 service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor 375 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 316 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 316 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 374 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 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX may modulate an RF carrier with a respective spatial stream for transmission.

At the UE 350, each receiver 354RX receives a signal through its respective antenna 352. Each receiver 354RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 may perform spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they may be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 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 310. These soft decisions may be based on channel estimates computed by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station 310 on the physical channel. The data and control signals are then provided to the controller/processor 359, which implements layer 3 and layer 2 functionality.

The controller/processor 359 can be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller/processor 359 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 359 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 310, the controller/processor 359 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 358 from a reference signal or feedback transmitted by the base station 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antenna 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a respective spatial stream for transmission.

The UL transmission is processed at the base station 310 in a manner similar to that described in connection with the receiver function at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370.

The controller/processor 375 can be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the controller/processor 375 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 350. IP packets from the controller/processor 375 may be provided to the EPC 160. The controller/processor 375 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

At least one of the TX processor 368, the RX processor 356, and the controller/processor 359 may be configured to perform aspects in connection with 198 of FIG. 1.

At least one of the TX processor 316, the RX processor 370, and the controller/processor 375 may be configured to perform aspects in connection with 199 of FIG. 1.

Some aspects of wireless communication support sounding reference signal (SRS) resources that span a number of adjacent symbols, e.g., one, two, or four symbols, with a number of ports per SRS resource, e.g., up to four ports per SRS resource. In some aspects, the SRS resource can help a base station to determine an uplink channel. Additionally, each port of an SRS may be sounded in each symbol in which the SRS resource is configured. In some instances, an SRS may be transmitted in a number of symbols of a slot, e.g., the last six symbols of a slot. Further, an SRS may be transmitted after a data channel, e.g., a PUSCH, in a particular slot.

In some instances, an SRS resource set may contain a set of SRS resources transmitted by a UE. For instance, an SRS resource set may be transmitted in an aperiodic (AP) manner, e.g., DCI signaled, a semi-persistent (SP) manner, or a periodic (P) manner. A UE may be configured with multiple resources, which may be grouped in a SRS resource set depending on ta use case, e.g., antenna switching, codebook-based, non-codebook based, or beam management. Additionally, an SRS transmission may be wideband or subband. And an SRS bandwidth may include multiple physical resource blocks (PRBs) , e.g., four PRBs.

In some aspects of wireless communications, there may be a number of different SRS priority rules. For example, the collision of two AP SRS resource sets may be determined by implementation. And in some instances, there may be no agreed upon SRS priority rules. For instance, an AP SRS may be prioritized over an SP SRS, and an SP SRS may be prioritized over a P SRS. Additionally, when an SRS resource with an SRS-resourceType set as aperiodic is triggered on an OFDM symbol configured with a periodic or semi-persistent SRS transmission, the UE may transmit the aperiodic SRS resource and not transmit the periodic or semi-persistent SRS resource (s) overlapping within the symbol (s) . Also, when an SRS resource with SRS-resourceType set as semi-persistent is triggered on an OFDM symbol configured with periodic SRS transmission, the UE may transmit the semi-persistent SRS resource and not transmit the periodic SRS resource (s) overlapping within the symbol (s) .

In some aspects, an AP SRS triggering mechanism can be included, where the AP SRS can be triggered in a downlink or uplink DCI, as well as in a group common DCI. In some aspects, the downlink or uplink DCI can include an SRS request field, which can be a number of bits, e.g., two bits. Also, each AP SRS set can be associated or tagged with a number, e.g., one, two, or three. After this, the UE can monitor for DCI. For example, when a bit value is 01, then all sets that are associated with a value of 01 may be triggered. The UE can also transmit the SRS after it confirms a positive request.

In addition, each AP SRS set can be configured in radio resource control (RRC) signaling, e.g., including a slotOffset value between 0 and 32. The slotOffset value can be an offset in the number of slots between the triggering DCI and the actual transmission of the SRS resource set. In some instances, if the field is absent, the UE may not apply an offset, e.g., indicate a value of 0. Also, each SRS resource of a set can have an associated symbol index of the first symbol containing the SRS resource, i.e., a startPosition. In some instance, this can be how the UE determines in which slot it should transmit. Further, an SRS resource may span multiple consecutive OFDM symbols.

Aspects of the present disclosure can also include a carrier index in SRS triggering. In some aspects, if the UE is configured with a carrier indicator field, e.g., via CrossCarrierSchedulingConfig, the serving cell of a triggered SRS can be indicated by the carrier indicator field. For example, this can apply for uplink DCI, e.g., a DCI format of 0_1 or 1_1. In some instances, if there is an SRS request, it can be transmitted in the same SRS carrier that is used for a PUSCH. So one DCI can be used to schedule a carrier for a PUSCH and an SRS.

Additionally, certain DCI formats, e.g., a DCI format of 1_1, can be used for scheduling a PDSCH in a cell. Some information can also be transmitted by means of certain DCI formats, e.g., a DCI format of 1_1, with a cyclic redundancy check (CRC) scrambled by cell radio network temporary identifier (C-RNTI) , a configured scheduling RNTI (CS-RNTI) , or a modulation and coding scheme RNTI (MCS-C-RNTI) . For example, an identifier for DCI formats, e.g., one bit, can be transmitted via a DCI format of 1_1. Additionally, a value of a bit field for a DCI format of 1_1 can be set to 1, which can indicate a downlink DCI format. Further, a carrier indicator, e.g., 0 or 3 bits, can be transmitted via a DCI format of 1_1. Also, an SRS request can be transmitted via a DCI format, e.g., two bits for UEs not configured with supplementaryUplink in ServingCellConfig in the cell, or three bits for UEs configured with supplementaryUplink in ServingCellConfig in the cell where the first bit is the supplementary uplink (SUL) or non-SUL indicator, where the second and third bits may be defined by a table. The aforementioned bit field may also indicate an associated CSI-RS.

As indicated above, the aforementioned processes can be used for a carrier with a configured PUSCH or PUCCH. For a carrier without a configured PUSCH or PUCCH configured, an SRS carrier switching mechanism can be employed. For instance, the SRS carrier switching can be triggered by the DCI format that is transmitted. In some instances, this can be referred to as a group common DCI. For example, for an aperiodic SRS triggered in a DCI format, e.g., DCI format 2_3, and if a UE is configured with higher layer parameter, e.g., srs-TPC-PDCCH-Group set to typeA and given by SRS-CarrierSwitching without a PUSCH or PUCCH transmission, the order of the triggered SRS transmission on the serving cells may follow the order of the serving cells in the indicated set of serving cells configured by higher layers. In some instances, the UE in each serving cell can transmit the configured one or two SRS resource set (s) with a higher layer parameter usage set to antennaSwitching and a higher layer parameter resourceType in SRS-ResourceSet set to aperiodic.

For an aperiodic SRS triggered in DCI format 2_3 and if a UE is configured with a higher layer parameter, e.g., srs-TPC-PDCCH-Group set to typeB without a PUSCH or PUCCH transmission, the order of the triggered SRS transmission on the serving cells can follow the order of the serving cells with an aperiodic SRS triggered in the DCI, and the UE in each serving cell can transmit the configured one or two SRS resource set (s) with a higher layer parameter usage set to antennaSwitching and a higher layer parameter resourceType in SRS-ResourceSet set to aperiodic.

In some aspects, a UE can be configured with SRS resource (s) on a carrier c ₁ with slot formats comprised of downlink and uplink symbols and not configured for PUSCH or PUCCH transmission. For carrier c ₁, the UE can be configured with a higher layer parameter, e.g., srs-SwitchFromServCellIndex and srs-SwitchFromCarrier, where the switching from carrier c ₂ can be configured for PUSCH or PUCCH transmission. During an SRS transmission on carrier c ₁, the UE can temporarily suspend the uplink transmission on carrier c ₂.

For an n ^th (n ≥ 1) aperiodic SRS transmission on a cell c, upon detection of a positive SRS request on a grant, a UE can commence the SRS transmission on the configured symbol and slot. This can occur if it is no earlier than the summation of: the maximum time duration between the two durations spanned by N OFDM symbols of the numerology of cell c and the cell carrying the grant respectively, and the uplink or downlink RF retuning time. Further, this can occur if the SRS transmission does not collide with any previous SRS transmissions, or interruption due to uplink or downlink RF retuning time. Otherwise, n ^th SRS transmission may be dropped, where N is the reported capability as the minimum time interval in the unit of symbols, between the DCI triggering and the aperiodic SRS transmission.

In some aspects, a DCI format of 2_3 can be applicable for uplink carrier (s) of serving cells where a UE may not configured for PUSCH or PUCCH transmission or for uplink carrier (s) of a serving cell where srs-PowerControlAdjustmentStates can indicate a separate power control adjustment state between SRS transmissions and PUSCH transmissions. Additionally, a UE configured by higher layers with a parameter carrierSwitching can be provided.

In some aspects, a PUSCH and a PDSCH can be configured in multiple channels in an uplink carrier aggregation (CA) . Moreover, in some instances, one component carrier (CC) can be used to schedule a single CC. However, in some aspects, a single CC can be used to schedule multiple SRSs in one or more CCs.

Aspects of the present disclosure can trigger multiple AP SRS resources on multiple CCs, e.g., in scenarios with a PUSCH or PUCCH configured in uplink carrier aggregation (CA) . For instance, aspects of the present disclosure can enable, with one DCI, e.g., an uplink, downlink, or group common DCI, to trigger multiple AP SRS resource sets jointly on different uplink carriers, which can have a PUSCH or PUCCH configured in uplink CA. For example, aspects of the present disclosure can include a first SRS, i.e., SRS1, in a first CC, i.e., CC1, and SRS2 in CC2, as well as SRS4 in CC4. In these instances, all the CCs may be configured for uplink CA and there may be no need for carrier switching. Also, the SRS triggering of the present disclosure can include both intra-band and inter-band CA. The SRS resources can also have a slot offset, and can be transmitted on the same OFDM symbols based on UE capability.

In one aspect of the present disclosure, when the UE receives an SRS request field in a DCI from a first CC, e.g., an SRS request field value of 01 in CC1, the UE may transmit all SRS resource sets in the respective active bandwidth part (BWP) . For example, the BWP of all CCs that are associated with a codepoint can be in the respective CC. In some instances, the carrier index field in the DCI may not be used for SRS triggering, but rather for PUSCH or PDSCH scheduling depending on whether it is a downlink or uplink DCI.

FIG. 4 is a diagram 400 illustrating an example of SRS triggering. As shown in FIG. 4, if DCI is received that indicates an SRS request field of 01, then a number of different SRSs can be scheduled. So a single DCI with an SRS request can result in the scheduling of all SRSs. For example, receiving the DCI in a first CC, i.e., CC1, with an SRS request field of 01, can result in scheduling or triggering the corresponding SRSs in each of the remaining active CCs. For example, receiving the DCI in CC1 with an SRS request field of 01 can result in scheduling SRS1 in CC1, SRS1 in CC2, SRS4 in CC3, and SRS2 in CC4

As indicated above, aspects of the present disclosure can receive the DCI in one CC out of a group of CCs. This DCI can trigger the SRS configuration, and then the UE can be expected to transmit the SRSs in the corresponding CCs. So a base station may schedule the SRS and transmit the scheduling to the UE, and then the UE may transmit the SRS resource sets on a plurality of CCs based on the DCI. Also, the transmitted SRS can active and associated with a CC.

In another aspect of the present disclosure, in each CC for each AP SRS resource set configuration, a CC field can be added. This CC field may have multiple CC indexes which correspond to the CC indexes from which a DCI can be received. Further, this may trigger a specific AP SRS resource set.

FIG. 5 is a diagram 500 illustrating an example of SRS triggering. As shown in FIG. 5, in a first CC, i.e., CC1, SRS1 can be associated with CC1, CC2, CC4 and a codepoint value of 01. As such, whenever a DCI is received with a codepoint value of 01, the UE may understand that it will transmit a first SRS, e.g., SRS1. Here, SRS1 associated with codepoint value of 01 may be triggered if the DCI is received on a subset of the CCs. Also, this subset of CCs can be separately configured. So each SRS can be associated with a subset of CCs and a codepoint value. Accordingly, an SRS can be associated with a subset of CCs, and this subset of CCs can be where the DCI is transmitted.

As shown in FIG. 5, when a DCI is received from CC1 with a codepoint value of 01, SRS1 of CC1 can be triggered in CC1, CC2, or CC4. Also, when a DCI is received from CC1 with a codepoint value of 01, SRS1 of CC2 can be triggered in CC1. Moreover, when a DCI is received from CC1 with a codepoint value of 01, SRS1 of CC3 can be triggered in CC3. Further, when a DCI is received from CC1 with a codepoint value of 01, SRS1 of CC4 can be triggered in CC4.

In another aspect of the present disclosure, in each CC for each SRS request codepoint value, a CC field can be added. This CC field may have multiple CC indexes which correspond to the CC indexes to which all associated AP SRS resource sets are triggered. Further, in this aspect, the codepoint value can be associated with a subset of CCs. So whenever a DCI is received in a certain CC with a certain codepoint value, an SRS may be transmitted on the subset of CCs associated with this codepoint value. In some aspects, the CC index may be part of the configuration of the DCI field.

FIG. 6 is a diagram 600 illustrating an example of SRS triggering. As shown in FIG. 6, when DCI is received in a first CC, e.g., CC1, a first codepoint value, e.g., codepoint 01, can be associated with CC1, CC2, or CC4. As such, an SRS may be transmitted on CC1, CC2, or CC4. Also, codepoint value 10 can be associated with CC1 and CC2. As such, a DCI received in CC1 with codepoint 10 can result in an SRS transmission on CC1 or CC2. So when a DCI is received on CC1 with an SRS codepoint of 01, each of the SRS resource sets configured in CC1, each of which are associated with codepoint 01, may be triggered in CC1, CC2, or CC4.

As further in FIG. 6, DCI received in CC2 with a codepoint value 01 can result in an SRS transmission on CC1 or CC2. So when a DCI is received on CC2 with an SRS codepoint of 01, each of the SRS resource sets configured in CC2 which are associated with codepoint value 01 may be triggered in CC1 and CC2. Also, a DCI received in CC2 with a codepoint value 10 can result in an SRS transmission on CC2.

Additionally, DCI received in CC3 with codepoint value 01 can result in an SRS transmission on CC3. Further, a DCI received in CC3 with codepoint value 10 can result in an SRS transmission on CC1 or CC2. Moreover, DCI received in CC4 with codepoint value 01 can result in an SRS transmission on CC4. And a DCI received in CC4 with codepoint value 10 can result in an SRS transmission on CC2 or CC3.

In another aspect of the present disclosure, a carrier index can be reused. For instance, in each CC, for each value of the carrier index, e.g., values 0 through 7, a field can be configured with radio resource control (RRC) signaling or a medium access control (MAC) control element (CE) . This can include which CC (s) are triggered for a PUSCH and/or PDSCH, i.e., PxSCH, and which CC (s) are used for SRS triggering. So aspects of the present disclosure can use RRC signaling or a MAC CE to define the CC index. Additionally, each SRS request codepoint values in this CC may result in AP SRS being triggered on the CCs configured in the carrier index. If no field is configured for SRS, i.e., the SRS is not configured, then the same CC as that used for the PUSCH and PDSCH may be used for an SRS, i.e., this can be default or legacy behavior.

FIG. 7 is a diagram 700 illustrating an example of SRS triggering. As shown in FIG. 7, each of the plurality of CCs can include at least one carrier index field associated with RRC signaling or a MAC CE. Also, one of the at least one carrier index field can indicate a shared channel transmission component carrier and a plurality of CCs for SRS transmission. For example, a CC index of 0 can correspond to a PUSCH and/or PDSCH, i.e., PxSCH, in CC1 and an SRS in CC1 or CC2. Further, a CC index of 1 can correspond to a PxSCH in CC2 and an SRS in CC1 or CC4. A CC index of 2 can correspond to a PxSCH in CC3 and an SRS in CC1. Additionally, a CC index of 3 can correspond to a PxSCH in CC4 and an empty SRS.

In another aspect of the present disclosure, in each CC, a new carrier index, e.g., including values between 0 and 7, can be configured in DCI, which is configured in RRC signaling or a MAC CE. This can also include which CC (s) are used for SRS triggering. Further, all SRS request codepoint values in this CC may result in AP SRS being triggered on the CCs configured in the carrier index. If no field is configured for the SRS, then the same CC as that used for the PxSCH may be used for the SRS, i.e., this can be default or legacy behavior.

FIG. 8 is a diagram 800 illustrating an example of SRS triggering. As shown in FIG. 8, the carrier index field can include a first field that indicates the shared channel transmission component carrier, e.g., the CC for PUSCH and/or PDSCH, i.e., PxSCH. For example, a first carrier index field, i.e., CC index1, of 0 can correspond to a PxSCH in CC1. Further, a CC index1 of 1 can correspond to a PxSCH in CC2. A CC index1 of 2 can correspond to a PxSCH in CC3. And a CC index1 of 3 can correspond to a PxSCH in CC4.

Also, the carrier index field can include a second field, i.e., CC index2, that indicates the plurality of CCs for SRS transmission. For example, a CC index2 of 0 can correspond to an SRS in CC1 or CC2. Also, a CC index2 of 1 can correspond to an SRS in CC1 or CC4. A CC index2 of 2 can correspond to an SRS in CC1. Further, a CC index2 that is not configured in the DCI can correspond to a CC index2 being equal to the CC index1 value.

In some aspects, AP SRS resource sets can be for a number of different options, e.g., codebook-based SRS, non-codebook-based (NCB) SRS, antenna switching, uplink beam management, and/or positioning. In case of NCB SRS, an SRS request can trigger one or multiple CSI-RS resources on the same or different CC (s) as the triggered AP SRS resource sets for NCB. Additionally, having different CCs for the CSI-RS to measure in one carrier and transmit non-codebook SRS on the other carrier may make sense in a uplink partial-reciprocity in frequency domain scenario, e.g., when the UE is using angle, delay-spread estimation, extrapolation by implementation to derive the uplink precoder on a different carrier.

Aspects of the present disclosure can also utilize joint triggering of AP-CSI with AP SRS, such that a number of options may be produced. For instance, one DCI in CC1 can jointly trigger an AP-CSI associated with a CSI-RS received in CC2, a AP SRS transmitted in CC3, while a channel state information (CSI) report can be expected to be transmitted by the UE in CC4. Certain scenarios may find the above useful, e.g., spending DCI resources in a low-loaded downlink CC, while triggering CSI-RS in CC2, and SRS in CC3, spatial reciprocity in both by implementation to derive CSI for both CC2 and CC3, and/or while obtaining the CSI report in a low-loaded uplink CC.

FIG. 9 is a diagram 900 illustrating example communication between a UE 902 and a base station 904. At 910, the base station 904 may schedule for uplink transmissions on multiple CCs, where the multiple CCs may include uplink data or may be configured for a control channel transmission. At 920, the base station 904 may transmit the scheduling for the uplink transmissions, e.g., scheduling for uplink transmissions 922, on the multiple CCs. At 930, the UE 902 may receive the scheduling for the uplink transmissions, e.g., scheduling for uplink transmissions 922, on the multiple CCs, where the multiple CCs may include uplink data or may be configured for a control channel transmission.

At 940, the base station 904 may transmit a DCI, e.g., DCI 942, on a first CC of the multiple CCs, where the DCI can include a sounding reference signal (SRS) request field for the triggering of one or more aperiodic SRS resource sets. At 950, the UE 902 may receive the DCI, e.g., DCI 942, on the first CC of the multiple CCs, where the DCI can include a sounding reference signal (SRS) request field for the triggering of one or more aperiodic SRS resource sets. In some aspects, one of the one or more aperiodic SRS resource sets may be configured in a second CC of the multiple CCs and may be configured to be transmitted in at least one third CC of the multiple CCs. At 960, the UE 902 may transmit one or more aperiodic SRS resource sets, e.g., aperiodic SRS resource sets 962, on the at least one third CC based on at least one of the DCI or an SRS configuration. At 970, the base station 904 may receive the one or more aperiodic SRS resource sets, e.g., aperiodic SRS resource sets 962, on the at least one third CC based on at least one of the DCI or an SRS configuration.

In some aspects, the first CC can be distinct from the second CC and the at least one third CC, and the second CC can be distinct from the at least one third CC. Additionally, the multiple CCs can be associated with an uplink carrier aggregation (CA) configuration. Moreover, the one or more aperiodic SRS resources sets can be received on a same symbol of the multiple CCs. In some instances, each of the one or more aperiodic SRS resource sets can be associated with at least one codepoint value of the SRS request field, and each of the one or more aperiodic SRS resource sets associated with the codepoint value of the SRS request field can be transmitted in an active bandwidth part of the second CC. Also, each of the one or more aperiodic SRS resource sets configured in the multiple CCs can be transmitted. Further, each of the one or more aperiodic SRS resource sets configured in the multiple CCs can be transmitted in an active bandwidth part of a subset of the multiple CCs. The one or more aperiodic SRS resource sets can also be associated with at least one codepoint value.

In some aspects, the one or more aperiodic SRS resource sets can be associated with at least one codepoint value, where the at least one codepoint value can be associated with a subset of the multiple CCs. Additionally, each of the multiple CCs can include at least one carrier index field associated with at least one of radio resource control (RRC) signaling or a medium access control (MAC) control element (CE) . Moreover, one of the at least one carrier index field can indicate both a shared channel transmission component carrier and the plurality of CCs for SRS transmission. The one of the at least one carrier index field can also include a first field indicating the shared channel transmission component carrier and a second field indicating the plurality of CCs for SRS transmission.

FIG. 10 is a flowchart 1000 of a method of wireless communication. The method may be performed by a UE or a component of a UE (e.g., the

UE

104, 350, 902; an apparatus; a processing system, which may include the memory 360 and which may be the entire UE or a component of the UE, such as the TX processor 368, the RX processor 356, and/or the controller/processor 359) . Optional aspects are illustrated with a dashed line. The methods described herein can provide a number of benefits, such as improving communication signaling, resource utilization, and/or power savings.

At 1002, the UE may receive scheduling for the uplink transmissions on multiple CCs, where the multiple CCs can include uplink data or can be configured for a control channel transmission, as described in connection with the examples in FIGs. 4-9. At 1004, the UE may receive a DCI on a first CC of the multiple CCs, where the DCI can include a sounding reference signal (SRS) request field for the triggering of one or more aperiodic SRS resource sets, as described in connection with the examples in FIGs. 4-9. In some aspects, one of the one or more aperiodic SRS resource sets may be configured in a second CC of the multiple CCs and may be configured to be transmitted in at least one third CC of the multiple CCs. At 1006, the UE may transmit one or more aperiodic SRS resource sets on the at least one third CC based on at least one of the DCI or an SRS configuration, as described in connection with the examples in FIGs. 4-9.

In some instances, the first CC can be distinct from the second CC and the at least one third CC, and the second CC can be distinct from the at least one third CC. Additionally, the multiple CCs can be associated with an uplink carrier aggregation (CA) configuration, as described in connection with the examples in FIGs. 4-9. The one or more aperiodic SRS resources sets can be transmitted on a same symbol of the multiple CCs, as described in connection with the examples in FIGs. 4-9. In some aspects, each of the one or more aperiodic SRS resource sets can be associated with at least one codepoint value of the SRS request field, and each of the one or more aperiodic SRS resource sets associated with the codepoint value of the SRS request field can be transmitted in an active bandwidth part of the second CC, as described in connection with the examples in FIGs. 4-9. Also, each of the one or more aperiodic SRS resource sets configured in the multiple CCs can be transmitted, as described in connection with the examples in FIGs. 4-9. Further, each of the one or more aperiodic SRS resource sets configured in the multiple CCs can be transmitted in an active bandwidth part of a subset of the multiple CCs, as described in connection with the examples in FIGs. 4-9. Also, the one or more aperiodic SRS resource sets can be associated with at least one codepoint value, as described in connection with the examples in FIGs. 4-9.

The one or more SRS aperiodic resource sets can also be associated with at least one codepoint value, where the at least one codepoint value can be associated with a subset of the multiple CCs, as described in connection with the examples in FIGs. 4-9. Each of the multiple CCs can include at least one carrier index field associated with at least one of radio resource control (RRC) signaling or a medium access control (MAC) control element (CE) , as described in connection with the examples in FIGs. 4-9. Further, one of the at least one carrier index field can indicate both a shared channel transmission component carrier and the plurality of CCs for SRS transmission, as described in connection with the examples in FIGs. 4-9. The one of the at least one carrier index field can also include a first field indicating the shared channel transmission component carrier and a second field indicating the plurality of CCs for SRS transmission, as described in connection with the examples in FIGs. 4-9.

FIG. 11 is a flowchart 1100 of a method of wireless communication. The method may be performed by a base station or a component of a base station (e.g., the

base station

102, 310, 904; an apparatus; a processing system, which may include the memory 376 and which may be the entire base station or a component of the base station, such as the TX processor 316, the RX processor 370, and/or the controller/processor 375) . Optional aspects are illustrated with a dashed line. The methods described herein can provide a number of benefits, such as improving communication signaling, resource utilization, and/or power savings.

At 1102, the base station may schedule for uplink transmissions on multiple CCs, where the multiple CCs may include uplink data or are configured for a control channel transmission, as described in connection with the examples in FIGs. 4-9. At 1104, the base station may transmit the scheduling for the uplink transmissions on the multiple CCs, as described in connection with the examples in FIGs. 4-9. At 1106, the base station may transmit a DCI on a first CC of the multiple CCs, where the DCI can include a sounding reference signal (SRS) request field for the triggering of one or more aperiodic SRS resource sets, as described in connection with the examples in FIGs. 4-9. In some aspects, one of the one or more aperiodic SRS resource sets may be configured in a second CC of the multiple CCs and may be configured to be transmitted in at least one third CC of the multiple CCs. At 1108, the base station may receive the one or more aperiodic SRS resource sets on the at least one third CC based on at least one of the DCI or an SRS configuration, as described in connection with the examples in FIGs. 4-9.

In some aspects, the first CC can be distinct from the second CC and the at least one third CC, and the second CC can be distinct from the at least one third CC. Additionally, the multiple CCs can be associated with an uplink carrier aggregation (CA) configuration, as described in connection with the examples in FIGs. 4-9. Moreover, the one or more aperiodic SRS resources sets can be received on a same symbol of the multiple CCs, as described in connection with the examples in FIGs. 4-9. In some instances, each of the one or more aperiodic SRS resource sets can be associated with at least one codepoint value of the SRS request field; and each of the one or more aperiodic SRS resource sets associated with the codepoint value of the SRS request field can be received in an active bandwidth part of the second CC, as described in connection with the examples in FIGs. 4-9. In some aspects, each of the one or more aperiodic SRS resource sets configured in the multiple CCs can be received. Further, each of the one or more aperiodic SRS resource sets configured in the multiple CCs can be transmitted in an active bandwidth part of a subset of the multiple CC, as described in connection with the examples in FIGs. 4-9. The one or more aperiodic SRS resource sets can also be associated with at least one codepoint value, as described in connection with the examples in FIGs. 4-9.

In some aspects, the one or more aperiodic SRS resource sets can be associated with at least one codepoint value, where the at least one codepoint value can be associated with a subset of the multiple CCs, as described in connection with the examples in FIGs. 4-9. Additionally, each of the multiple CCs can include at least one carrier index field associated with at least one of radio resource control (RRC) signaling or a medium access control (MAC) control element (CE) , as described in connection with the examples in FIGs. 4-9. Moreover, one of the at least one carrier index field can indicate both a shared channel transmission component carrier and the plurality of CCs for SRS transmission, as described in connection with the examples in FIGs. 4-9. The one of the at least one carrier index field can also include a first field indicating the shared channel transmission component carrier and a second field indicating the plurality of CCs for SRS transmission, as described in connection with the examples in FIGs. 4-9.

Further disclosure is included in the Appendix.

It is understood that the specific order or hierarchy of blocks in the processes /flowcharts disclosed is an illustration of example 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. ”

Claims

A method of wireless communication of a user equipment (UE) , comprising:

receiving scheduling for uplink transmissions on multiple component carriers (CCs) , wherein the multiple CCs include uplink data or are configured for a control channel transmission;

receiving a downlink control information (DCI) on a first CC of the multiple CCs, wherein the DCI includes a sounding reference signal (SRS) request field for triggering one or more aperiodic SRS resource sets;

wherein one of the one or more aperiodic SRS resource sets is configured in a second CC of the multiple CCs and is configured to be transmitted in at least one third CC of the multiple CCs; and

transmitting the one or more aperiodic SRS resource sets on the at least one third CC based on at least one of the DCI or an SRS configuration.
The method of claim 1, wherein the first CC is distinct from the second CC and the at least one third CC, and the second CC is distinct from the at least one third CC.
The method of claim 1, wherein the multiple CCs are associated with an uplink carrier aggregation (CA) configuration.
The method of claim 1, wherein the one or more aperiodic SRS resources sets are transmitted on a same symbol of the multiple CCs.
The method of claim 1, wherein each of the one or more aperiodic SRS resource sets is associated with at least one codepoint value of the SRS request field; and

wherein each of the one or more aperiodic SRS resource sets associated with the codepoint value of the SRS request field is transmitted in an active bandwidth part of the second CC.
The method of claim 5, wherein each of the one or more aperiodic SRS resource sets configured in the multiple CCs is transmitted.
The method of claim 1, wherein each of the one or more aperiodic SRS resource sets configured in the multiple CCs is transmitted in an active bandwidth part of a subset of the multiple CCs.
The method of claim 7, wherein the one or more SRS aperiodic resource sets are associated with at least one codepoint value.
The method of claim 1, wherein the one or more aperiodic SRS resource sets are associated with at least one codepoint value, the at least one codepoint value being associated with a subset of the multiple CCs.
The method of claim 1, wherein each of the multiple CCs include at least one carrier index field associated with at least one of radio resource control (RRC) signaling or a medium access control (MAC) control element (CE) .
The method of claim 10, wherein one of the at least one carrier index field indicates both a shared channel transmission component carrier and the plurality of CCs for SRS transmission.
The method of claim 11, wherein the one of the at least one carrier index field includes a first field indicating the shared channel transmission component carrier and a second field indicating the plurality of CCs for SRS transmission.
An apparatus for wireless communication of a user equipment (UE) , comprising:

a memory; and

at least one processor coupled to the memory and configured to:

receive scheduling for uplink transmissions on multiple component carriers (CCs) , wherein the multiple CCs include uplink data or are configured for a control channel transmission;

receive downlink control information (DCI) on a first CC of the multiple CCs, wherein the DCI includes a sounding reference signal (SRS) request field for the triggering of one or more aperiodic SRS resource sets;

wherein one of the one or more aperiodic SRS resource sets is configured in a second CC of the multiple CCs and is configured to be transmitted in at least one third CC of the multiple CCs; and

transmit the one or more aperiodic SRS resource sets on the at least one third CC based on at least one of the DCI or an SRS configuration.
The apparatus of claim 13, wherein the first CC is distinct from the second CC and the at least one third CC, and the second CC is distinct from the at least one third CC.
The apparatus of claim 13, wherein the multiple CCs are associated with an uplink carrier aggregation (CA) configuration.
The apparatus of claim 13, wherein the one or more aperiodic SRS resources sets are transmitted on a same symbol of the multiple CCs.
The apparatus of claim 13, wherein each of the one or more aperiodic SRS resource sets is associated with at least one codepoint value of the SRS request field; and

wherein each of the one or more aperiodic SRS resource sets associated with the codepoint value of the SRS request field is transmitted in an active bandwidth part of the second CC.
The apparatus of claim 13, wherein each of the one or more aperiodic SRS resource sets configured in the multiple CCs is transmitted.
The apparatus of claim 13, wherein each of the one or more aperiodic SRS resource sets configured in the multiple CCs is transmitted in an active bandwidth part of a subset of the multiple CCs.
The apparatus of claim 19, wherein the one or more aperiodic SRS resource sets are associated with at least one codepoint value.
The apparatus of claim 13, wherein the one or more aperiodic SRS resource sets are associated with at least one codepoint value, the at least one codepoint value being associated with a subset of the multiple CCs.
The apparatus of claim 13, wherein each of the multiple CCs include at least one carrier index field associated with at least one of radio resource control (RRC) signaling or a medium access control (MAC) control element (CE) .
The apparatus of claim 22, wherein one of the at least one carrier index field indicates both a shared channel transmission component carrier and the plurality of CCs for SRS transmission.
The apparatus of claim 23, wherein the one of the at least one carrier index field includes a first field indicating the shared channel transmission component carrier and a second field indicating the plurality of CCs for SRS transmission.
An apparatus for wireless communication of a user equipment (UE) , comprising:

means for receiving scheduling for uplink transmissions on multiple component carriers (CCs) , wherein the multiple CCs include uplink data or are configured for a control channel transmission;

means for receiving a downlink control information (DCI) on a first CC of the multiple CCs, wherein the DCI includes a sounding reference signal (SRS) request field for the triggering of one or more aperiodic SRS resource sets;

wherein one of the one or more aperiodic SRS resource sets is configured in a second CC of the multiple CCs and is configured to be transmitted in at least one third CC of the multiple CCs; and

means for transmitting the one or more aperiodic SRS resource sets on the at least one third CC based on at least one of the DCI or an SRS configuration.
The apparatus of claim 25, wherein the first CC is distinct from the second CC and the at least one third CC, and the second CC is distinct from the at least one third CC.
The apparatus of claim 25, wherein the multiple CCs are associated with an uplink carrier aggregation (CA) configuration.
The apparatus of claim 25, wherein the one or more aperiodic SRS resources sets are transmitted on a same symbol of the multiple CCs.
The apparatus of claim 25, wherein each of the one or more aperiodic SRS resource sets is associated with at least one codepoint value of the SRS request field; and

wherein each of the one or more aperiodic SRS resource sets associated with the codepoint value of the SRS request field is transmitted in an active bandwidth part of the second CC.
The apparatus of claim 25, wherein each of the one or more aperiodic SRS resource sets configured in the multiple CCs is transmitted.
The apparatus of claim 25, wherein each of the one or more aperiodic SRS resource sets configured in the multiple CCs is transmitted in an active bandwidth part of a subset of the multiple CCs.
The apparatus of claim 31, wherein the one or more aperiodic SRS resource sets are associated with at least one codepoint value.
The apparatus of claim 25, wherein the one or more aperiodic SRS resource sets are associated with at least one codepoint value, the at least one codepoint value being associated with a subset of the multiple CCs.
The apparatus of claim 25, wherein each of the multiple CCs include at least one carrier index field associated with at least one of radio resource control (RRC) signaling or a medium access control (MAC) control element (CE) .
The apparatus of claim 34, wherein one of the at least one carrier index field indicates both a shared channel transmission component carrier and the plurality of CCs for SRS transmission.
The apparatus of claim 35, wherein the one of the at least one carrier index field includes a first field indicating the shared channel transmission component carrier and a second field indicating the plurality of CCs for SRS transmission.
A computer-readable medium storing computer executable code for wireless communication of a user equipment (UE) , the code when executed by a processor cause the processor to:

receive scheduling for uplink transmissions on multiple component carriers (CCs) , wherein the multiple CCs include uplink data or are configured for a control channel transmission;

receive downlink control information (DCI) on a first CC of the multiple CCs, wherein the DCI includes a sounding reference signal (SRS) request field for the triggering of one or more aperiodic SRS resource sets;

wherein one of the one or more aperiodic SRS resource sets is configured in a second CC of the multiple CCs and is configured to be transmitted in at least one third CC of the multiple CCs; and

transmit the one or more aperiodic SRS resource sets on the at least one third CC based on at least one of the DCI or an SRS configuration.
A method of wireless communication of a base station, comprising:

scheduling for uplink transmissions on multiple component carriers (CCs) , wherein the multiple CCs include uplink data or are configured for a control channel transmission;

transmitting a downlink control information (DCI) on a first CC of the multiple CCs, wherein the DCI includes a sounding reference signal (SRS) request field for the triggering of one or more aperiodic SRS resource sets;

wherein one of the one or more aperiodic SRS resource sets is configured in a second CC of the multiple CCs and is configured to be transmitted in at least one third CC of the multiple CCs; and

receiving the one or more aperiodic SRS resource sets on the at least one third CC based on at least one of the DCI or an SRS configuration.
The method of claim 38, wherein the first CC is distinct from the second CC and the at least one third CC, and the second CC is distinct from the at least one third CC.
The method of claim 38, wherein the multiple CCs are associated with an uplink carrier aggregation (CA) configuration.
The method of claim 38, wherein the one or more aperiodic SRS resources sets are received on a same symbol of the multiple CCs.
The method of claim 38, further comprising:

transmitting the scheduling for the uplink transmissions on the multiple CCs.
The method of claim 38, wherein each of the one or more aperiodic SRS resource sets is associated with at least one codepoint value of the SRS request field; and

wherein each of the one or more aperiodic SRS resource sets associated with the codepoint value of the SRS request field is received in an active bandwidth part of the second CC.
The method of claim 43, wherein each of the one or more aperiodic SRS resource sets configured in the multiple CCs is received.
The method of claim 38, wherein each of the one or more aperiodic SRS resource sets configured in the multiple CCs is transmitted in an active bandwidth part of a subset of the multiple CC.
The method of claim 45, wherein the one or more aperiodic SRS resource sets are associated with at least one codepoint value.
The method of claim 38, wherein the one or more aperiodic SRS resource sets are associated with at least one codepoint value, the at least one codepoint value being associated with a subset of the multiple CCs.
The method of claim 38, wherein each of the multiple CCs include at least one carrier index field associated with at least one of radio resource control (RRC) signaling or a medium access control (MAC) control element (CE) .
The method of claim 48, wherein one of the at least one carrier index field indicates both a shared channel transmission component carrier and the plurality of CCs for SRS transmission.
The method of claim 49, wherein the one of the at least one carrier index field includes a first field indicating the shared channel transmission component carrier and a second field indicating the plurality of CCs for SRS transmission.
An apparatus for wireless communication of a base station, comprising:

a memory; and

at least one processor coupled to the memory and configured to:

schedule for uplink transmissions on multiple component carriers (CCs) , wherein the multiple CCs include uplink data or are configured for a control channel transmission;

transmit a downlink control information (DCI) on a first CC of the multiple CCs, wherein the DCI includes a sounding reference signal (SRS) request field for the triggering of one or more aperiodic SRS resource sets;

wherein one of the one or more aperiodic SRS resource sets is configured in a second CC of the multiple CCs and is configured to be transmitted in at least one third CC of the multiple CCs; and

receive the one or more aperiodic SRS resource sets on the at least one third CC based on at least one of the DCI or an SRS configuration.
The apparatus of claim 51, wherein the first CC is distinct from the second CC and the at least one third CC, and the second CC is distinct from the at least one third CC.
The apparatus of claim 51, wherein the multiple CCs are associated with an uplink carrier aggregation (CA) configuration.
The apparatus of claim 51, wherein the one or more aperiodic SRS resources sets are received on a same symbol of the multiple CCs.
The apparatus of claim 51, wherein the at least one processor is further configured to:

transmit the scheduling for the uplink transmissions on the multiple CCs.
The apparatus of claim 51, wherein each of the one or more aperiodic SRS resource sets is associated with at least one codepoint value of the SRS request field; and

wherein each of the one or more aperiodic SRS resource sets associated with the codepoint value of the SRS request field is received in an active bandwidth part of the second CC.
The apparatus of claim 56, wherein each of the one or more aperiodic SRS resource sets configured in the multiple CCs is received.
The apparatus of claim 51, wherein each of the one or more aperiodic SRS resource sets configured in the multiple CCs is transmitted in an active bandwidth part of a subset of the multiple CC.
The apparatus of claim 58, wherein the one or more aperiodic SRS resource sets are associated with at least one codepoint value.
The apparatus of claim 51, wherein the one or more aperiodic SRS resource sets are associated with at least one codepoint value, the at least one codepoint value being associated with a subset of the multiple CCs.
The apparatus of claim 51, wherein each of the multiple CCs include at least one carrier index field associated with at least one of radio resource control (RRC) signaling or a medium access control (MAC) control element (CE) .
The apparatus of claim 61, wherein one of the at least one carrier index field indicates both a shared channel transmission component carrier and the plurality of CCs for SRS transmission.
The apparatus of claim 62, wherein the one of the at least one carrier index field includes a first field indicating the shared channel transmission component carrier and a second field indicating the plurality of CCs for SRS transmission.
An apparatus for wireless communication of a base station, comprising:

means for scheduling for uplink transmissions on multiple component carriers (CCs) , wherein the multiple CCs include uplink data or are configured for a control channel transmission;

means for transmitting a downlink control information (DCI) on a first CC of the multiple CCs, wherein the DCI includes a sounding reference signal (SRS) request field for the triggering of one or more aperiodic SRS resource sets;

wherein one of the one or more aperiodic SRS resource sets is configured in a second CC of the multiple CCs and is configured to be transmitted in at least one third CC of the multiple CCs; and

means for receiving the one or more aperiodic SRS resource sets on the at least one third CC based on at least one of the DCI or an SRS configuration.
The apparatus of claim 64, wherein the first CC is distinct from the second CC and the at least one third CC, and the second CC is distinct from the at least one third CC.
The apparatus of claim 64, wherein the multiple CCs are associated with an uplink carrier aggregation (CA) configuration.
The apparatus of claim 64, wherein the one or more aperiodic SRS resources sets are received on a same symbol of the multiple CCs.
The apparatus of claim 64, further comprising:

means for transmitting the scheduling for the uplink transmissions on the multiple CCs.
The apparatus of claim 64, wherein each of the one or more aperiodic SRS resource sets is associated with at least one codepoint value of the SRS request field; and

wherein each of the one or more aperiodic SRS resource sets associated with the codepoint value of the SRS request field is received in an active bandwidth part of the second CC.
The apparatus of claim 64, wherein each of the one or more aperiodic SRS resource sets configured in the multiple CCs is received.
The apparatus of claim 64, wherein each of the one or more aperiodic SRS resource sets configured in the multiple CCs is transmitted in an active bandwidth part of a subset of the multiple CC.
The apparatus of claim 71, wherein the one or more aperiodic SRS resource sets are associated with at least one codepoint value.
The apparatus of claim 64, wherein the one or more aperiodic SRS resource sets are associated with at least one codepoint value, the at least one codepoint value being associated with a subset of the multiple CCs.
The apparatus of claim 64, wherein each of the multiple CCs include at least one carrier index field associated with at least one of radio resource control (RRC) signaling or a medium access control (MAC) control element (CE) .
The apparatus of claim 74, wherein one of the at least one carrier index field indicates both a shared channel transmission component carrier and the plurality of CCs for SRS transmission.
The apparatus of claim 75, wherein the one of the at least one carrier index field includes a first field indicating the shared channel transmission component carrier and a second field indicating the plurality of CCs for SRS transmission.
A computer-readable medium storing computer executable code for wireless communication of a base station, the code when executed by a processor cause the processor to:

schedule for uplink transmissions on multiple component carriers (CCs) , wherein the multiple CCs include uplink data or are configured for a control channel transmission;

transmit a downlink control information (DCI) on a first CC of the multiple CCs, wherein the DCI includes a sounding reference signal (SRS) request field for the triggering of one or more aperiodic SRS resource sets;

wherein one of the one or more aperiodic SRS resource sets is configured in a second CC of the multiple CCs and is configured to be transmitted in at least one third CC of the multiple CCs; and

receive the one or more aperiodic SRS resource sets on the at least one third CC based on at least one of the DCI or an SRS configuration.