The uplink transmission configuration indicates the default uplink MIMO transmission before the state is activated.

Abstract

Various aspects of the present disclosure generally relate to wireless communications. In some aspects, a base station may send and a user equipment (UE) may receive downlink control information (DCI) that schedules uplink multiple-input multiple-output (MIMO) communications. The UE and the base station may send and receive uplink MIMO communications using a default sounding reference signal (SRS) resource configuration based at least in part on the UE receiving the DCI before a medium access control (MAC) control element (MAC‑CE) selects a subset of uplink TCI states included in a pool of uplink transmission configuration indication (TCI) states configured for the UE. Many other aspects are provided.

Description

Technical Field

[0001] Aspects of the present disclosure relate generally to wireless communications and techniques and apparatus for default uplink multiple-input multiple-output transmission prior to activation of an uplink transmission configuration indication state. Background Art

[0002] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). 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, time division synchronous code division multiple access (TD-SCDMA) systems, and long term evolution (LTE). LTE / LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP).

[0003] A wireless communication network may include multiple base stations (BS) that can support communications for multiple user equipment (UE). User equipment (UE) can communicate with a base station (BS) via a downlink and an uplink. A downlink (or forward link) refers to a communication link from a BS to a UE, while an uplink (or reverse link) refers to a communication link from a UE to a BS. As will be described in more detail herein, a BS may be referred to as a Node B, gNB, access point (AP), radio head, transmit receive point (TRP), new radio (NR) BS, 5G Node B, etc.

[0004] The above-mentioned multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user equipment to communicate at the city, country, region, and even global level. New Radio (NR) (also referred to as 5G) is an enhancement set of the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP). NR is designed to use orthogonal frequency division multiplexing (OFDM) (CP-OFDM) with cyclic prefix (CP) on the downlink (DL) and CP-OFDM and / or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL) to improve spectrum efficiency, reduce costs, improve services, utilize new spectrum, and better integrate with other open standards, as well as support beamforming, multiple input multiple output (MIMO) antenna technology, and carrier aggregation, and better support mobile broadband Internet access. However, as the demand for mobile broadband access continues to grow, there is a need to further improve LTE and NR technologies. Preferably, these improvements should be applicable to other multiple access technologies and telecommunication standards that adopt these technologies. Summary of the invention

[0005] In some aspects, a method of wireless communication performed by a user equipment (UE) may include: receiving downlink control information (DCI) scheduling uplink multiple-input multiple-output (MIMO) communication from a base station; and sending uplink MIMO communication to the base station using a default sounding reference signal (SRS) resource configuration based at least in part on receiving the DCI before a medium access control (MAC) control element (MAC-CE) selects a subset of uplink TCI states included in an uplink TCI state pool configured for the UE.

[0006] In some aspects, a method of wireless communication performed by a base station may include: sending a DCI scheduling uplink MIMO communication to a UE; and receiving uplink MIMO communication from the UE using a default SRS resource configuration based at least in part on the UE receiving the DCI before a MAC-CE selects a subset of uplink TCI states included in an uplink TCI state pool configured for the UE.

[0007] In some aspects, a UE for wireless communication may include a memory and one or more processors operably coupled to the memory. The memory and the one or more processors may be configured to: receive DCI scheduling uplink MIMO communication from a base station; and send uplink MIMO communication to the base station using a default SRS resource configuration based at least in part on receiving the DCI before a MAC-CE selects a subset of uplink TCI states included in an uplink TCI state pool configured for the UE.

[0008] In some aspects, a base station for wireless communication may include a memory and one or more processors operably coupled to the memory. The memory and the one or more processors may be configured to: send DCI scheduling uplink MIMO communication to a UE; and receive uplink MIMO communication from the UE using a default SRS resource configuration based at least in part on the UE receiving the DCI before a MAC-CE selects a subset of uplink TCI states included in an uplink TCI state pool configured for the UE.

[0009] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a UE, may cause the one or more processors to: receive DCI scheduling uplink MIMO communication from a base station; and send uplink MIMO communication to the base station using a default SRS resource configuration based at least in part on receiving the DCI before a MAC-CE selects a subset of uplink TCI states included in an uplink TCI state pool configured for the UE.

[0010] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a base station, may cause the one or more processors to: send DCI scheduling uplink MIMO communication to a UE; and receive uplink MIMO communication from the UE using a default SRS resource configuration based at least in part on the UE receiving the DCI before a MAC-CE selects a subset of uplink TCI states included in an uplink TCI state pool configured for the UE.

[0011] In some aspects, an apparatus for wireless communications may include: a component for receiving DCI scheduling uplink MIMO communications from a base station; and a component for sending uplink MIMO communications to the base station using a default SRS resource configuration based at least in part on receiving the DCI before a MAC-CE selects a subset of uplink TCI states included in an uplink TCI state pool configured for the apparatus.

[0012] In some aspects, an apparatus for wireless communication may include: a component for sending DCI scheduling uplink MIMO communication to a UE; and a component for receiving uplink MIMO communication from a UE using a default SRS resource configuration based at least in part on the UE receiving the DCI before a MAC-CE selects a subset of uplink TCI states included in an uplink TCI state pool configured for the UE.

[0013] Aspects generally include methods, apparatus, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, wireless communication devices, and / or processing systems as generally described herein with reference to and illustrated by the figures and description.

[0014] The foregoing has outlined quite extensively the features and technical advantages of examples according to the present disclosure so that the following detailed description may be better understood. Additional features and advantages will be described below. The disclosed concepts and specific examples may be readily utilized as a basis for modifying or designing other structures for achieving the same purpose of the present disclosure. Such equivalent structures do not depart from the scope of the appended claims. The characteristics of the concepts disclosed herein, both their organization and methods of operation, together with the associated advantages, will be better understood from the following description when considered in conjunction with the accompanying drawings. Each of the accompanying drawings is provided for the purpose of illustration and description and not as a definition of limitations to the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to enable the above-mentioned features of the present disclosure to be understood in detail, the above brief overview may be described in more detail by reference to various aspects (some of which are illustrated in the accompanying drawings). However, it should be noted that the accompanying drawings illustrate only certain typical aspects of the present disclosure and should not be considered as limiting the scope thereof, as the description may admit of other equally effective aspects. The same reference numerals in different drawings may identify the same or similar elements.

[0016] Figure 1 is a block diagram conceptually illustrating an example of a wireless communication network in accordance with various aspects of the present disclosure.

[0017] Figure 2 is a block diagram conceptually illustrating an example of a base station in communication with a UE in a wireless communication network according to various aspects of the present disclosure.

[0018] Figure 3 is a diagram illustrating an example call flow related to uplink multiple-input multiple-output (MIMO) communications in accordance with various aspects of the present disclosure.

[0019] Figure 4 is a diagram illustrating an example of default uplink MIMO transmission prior to uplink transmission configuration indication (TCI) state activation according to various aspects of the present disclosure.

[0020] Figure 5 is a diagram illustrating example processes performed, for example, by a UE according to various aspects of the present disclosure.

[0021] Figure 6 is a diagram illustrating example processes performed, for example, by a base station according to various aspects of the present disclosure. DETAILED DESCRIPTION

[0022] The various aspects of the present disclosure will be described more fully below with reference to the accompanying drawings. However, the present disclosure can be implemented in many different forms, and the present disclosure should not be interpreted as being limited to any specific structure or function presented throughout the present disclosure. On the contrary, these aspects are provided so that the present disclosure will become comprehensive and complete, and these aspects will fully convey the scope of the present disclosure to those skilled in the art. Based on the teachings of this article, it should be understood by those skilled in the art that the scope of the present disclosure is intended to cover any aspect of the present disclosure disclosed herein, whether it is realized independently of any other aspect of the present disclosure or realized in combination with any other aspect of the present disclosure. For example, any number of aspects set forth herein can be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such a device or method practiced using other structures, functions, or structures and functions other than the various aspects of the present disclosure set forth herein or different from the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the present disclosure disclosed herein can be implemented by one or more elements of the claim.

[0023] Several aspects of telecommunication systems will now be presented with reference to various devices and techniques. These devices and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using hardware, software, or a combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0024] It should be noted that although various aspects may be described herein using terminology generally associated with 3G and / or 4G wireless technologies, various aspects of the present disclosure may be applicable in communication systems based on other generations, such as 5G and later generations, including NR technology.

[0025] Figure 1 is a diagram illustrating a wireless network 100 in which various aspects of the present disclosure may be practiced. The wireless network 100 may be an LTE network or some other wireless network, such as a 5G or NR network. The wireless network 100 may include a plurality of BSs 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with a user equipment (UE), and it may also be referred to as a base station, NR BS, Node B, gNB, 5G Node B (NB), access point, transmit receive point (TRP), etc. Each BS may provide communication coverage for a specific geographic area. In 3GPP, the term "cell" may refer to a coverage area of ​​a BS and / or a BS subsystem serving this coverage area, depending on the context in which the term is used.

[0026] A BS may provide communication coverage for macro cells, pico cells, femto cells, and / or other types of cells. A macro cell may cover a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access by UEs with service subscriptions. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscriptions. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs associated with the femto cell (e.g., UEs in a Closed Subscriber Group (CSG)). The BS of a macro cell may be referred to as a macro BS. The BS of a pico cell may be referred to as a pico BS. The BS of a femto cell may be referred to as a femto BS or a home BS. In Figure 1 In the example shown, BS 110a may be a macro BS of macro cell 102a, BS 110b may be a pico BS of pico cell 102b, and BS 110c may be a femto BS of femto cell 102c. A BS may support one or more (e.g., three) cells. The terms "eNB", "base station", "NR BS", "gNB", "TRP", "AP", "Node B", "5G NB", and "cell" may be used interchangeably herein.

[0027] In some aspects, the cells are not necessarily fixed, and the geographic area of ​​the cells may move depending on the location of the mobile BS. In some aspects, the BSs may be interconnected with each other and / or with one or more other BSs or network nodes (not shown) in the wireless network 100 via various types of backhaul interfaces, such as direct physical connections, virtual networks, and / or similar interfaces using any suitable transport networks.

[0028] The wireless network 100 may also include a relay station. A relay station is an entity that can receive transmissions of data from an upstream station (e.g., a BS or a UE) and transmit transmissions of data to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that can relay transmissions for other UEs. Figure 1 In the example shown, a relay station 110d may communicate with a macro BS 110a and a UE 120d to facilitate communication between the BS 110a and the UE 120d. A relay station may also be referred to as a relay BS, a relay base station, a relay, or the like.

[0029] The wireless network 100 may be a heterogeneous network including different types of BSs (e.g., macro BSs, pico BSs, femto BSs, relay BSs, etc.). These different types of BSs may have different transmit power levels, different coverage areas, and different effects on interference in the wireless network 100. For example, a macro BS may have a high transmit power level (e.g., 5 to 40 watts), while a pico BS, a femto BS, and a relay BS may have a lower transmit power level (e.g., 0.1 to 2 watts).

[0030] A network controller 130 may be coupled to a set of BSs and may provide coordination and control for these BSs. The network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with each other (eg, directly or indirectly via a wireless or wired backhaul).

[0031] UE 120 (e.g., 120a, 120b, 120c) can be dispersed throughout the wireless network 100, and each UE can be fixed or mobile. UE can also be referred to as an access terminal, terminal, mobile station, subscriber unit, station, etc. UE can be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet computer, a camera, a gaming device, a netbook, a smart book, an ultrabook, a medical device or apparatus, a biosensor / device, a wearable device (smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicle component or sensor, a smart meter / sensor, an industrial manufacturing device, a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium.

[0032] Some UEs may be considered as UEs of machine type communication (MTC) or evolved or enhanced machine type communication (eMTC). For example, MTC and eMTC UEs include robots, drones, remote devices (such as sensors, meters, monitors, location tags), etc. that can communicate with a base station, another device (e.g., a remote device), or some other entity. For example, a wireless node may provide connectivity for a network or to a network (e.g., a wide area network such as the Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered as Internet of Things (IoT) devices, and / or may be implemented as NB-IoT (narrowband Internet of Things) devices. Some UEs may be considered as customer premise equipment (CPE). UE 120 may be included inside a housing that houses components (such as processor components, memory components, etc.) of UE 120. In some aspects, the processor component and the memory component may be coupled together. For example, a processor component (e.g., one or more processors) and a memory component (e.g., a memory) may be operably coupled, communicatively coupled, electronically coupled, electrically coupled, etc.

[0033] Typically, any number of wireless networks can be deployed in a given geographic area. Each wireless network can support a specific radio access technology (RAT) and can operate on one or more frequencies. RAT can also be referred to as radio technology, air interface, etc. Frequency can also be referred to as carrier, channel, etc. In a given geographic area, each frequency can support a single RAT to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks can be deployed.

[0034] In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using base station 110 as an intermediary for communicating with each other). For example, UE 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocols (e.g., which may include vehicle-to-vehicle (V2V) protocols, vehicle-to-infrastructure (V2I) protocols, etc.), mesh networks, etc. In this case, UE 120 may perform scheduling operations, resource selection operations, and / or other operations described elsewhere herein as being performed by base station 110.

[0035] As mentioned above, Figure 1 Other examples can be found in the Figure 1 The content described is different.

[0036] Figure 2 A block diagram of a design 200 of a base station 110 and a UE 120 is shown, which may be Figure 1 BS 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general T≥1 and R≥1.

[0037] At the base station 110, the transmit processor 220 may receive data for one or more UEs from the data source 212, select one or more modulation and coding schemes (MCS) for each UE based at least in part on a channel quality indicator (CQI) received from the UE, process (e.g., encode and modulate) the data for each UE based at least in part on the (multiple) MCS selected for the UE, and provide data symbols for all UEs. The transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI), etc.) and control information (e.g., CQI requests, grants, upper layer signaling, etc.), and provide overhead symbols and control symbols. The transmit processor 220 may also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS)) and synchronization signals (e.g., primary synchronization signals (PSS) and secondary synchronization signals (SSS)). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, overhead symbols, and / or reference symbols, if applicable, and may provide T output symbol streams to T modulators (MOD) 232a to 232t. Each modulator 232 may process a corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may also process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. T downlink signals from modulators 232a to 232t may be transmitted via T antennas 234a to 234t, respectively. According to various aspects described in more detail below, a synchronization signal may be generated using location coding to convey additional information.

[0038] At the UE 120, antennas 252a to 252r may receive downlink signals from the base station 110 and / or other base stations, and may provide received signals to demodulators (DEMODs) 254a to 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) the received signal to obtain input samples. Each demodulator 254 may also process the input samples (e.g., for OFDM, etc.) to obtain received symbols. The MIMO detector 256 may obtain received symbols from all R demodulators 254a to 254r, perform MIMO detection on the received symbols (if applicable), and provide detected symbols. The receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide decoded data for the UE 120 to the data sink 260, and provide decoded control information and system information to the controller / processor 280. The channel processor may determine reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), channel quality indicator (CQI), etc. In some aspects, one or more components of UE 120 may be included in a housing.

[0039] On the uplink, at the UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information from a controller / processor 280 (e.g., for reports including RSRP, RSSI, RSRQ, CQI, etc.). The transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 (if applicable), further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to the base station 110. At the base station 110, uplink signals from the UE 120 and other UEs may be received by the antenna 234, processed by the demodulator 232, detected by the MIMO detector 236 (if applicable), and further processed by the receive processor 238 to obtain decoded data and control information transmitted by the UE 120. The receive processor 238 may provide decoded data to a data sink 239 and decoded control information to a controller / processor 240. The base station 110 may include a communication unit 244 and communicate with the network controller 130 via the communication unit 244. The network controller 130 may include a communication unit 294, a controller / processor 290, and a memory 292.

[0040] As described in greater detail elsewhere herein, the controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2Any other component(s) of the UE 120 may perform one or more techniques associated with default uplink MIMO transmission prior to activation of the uplink transmission configuration indication (TCI) state. For example, the controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2 Any other component(s) may perform or direct e.g. Figure 5 The process of 500 Figure 6 600 and / or other processes described herein. Memories 242 and 282 may store data and program codes for base station 110 and UE 120, respectively. In some aspects, memory 242 and / or memory 282 may include a non-transitory computer-readable medium storing one or more instructions for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compilation, conversion, interpretation, etc.) by one or more processors of base station 110 and / or UE 120, may perform or direct, for example, Figure 5 The process of 500 Figure 6 The process 600 of , and / or operations of other processes described herein. In some aspects, executing instructions may include running instructions, converting instructions, compiling instructions, interpreting instructions, etc. The scheduler 246 may schedule UEs for data transmission on the downlink and / or uplink.

[0041] In some aspects, UE 120 may include: a component for receiving downlink control information (DCI) scheduling uplink MIMO communication from base station 110; and a component for sending uplink MIMO communication to base station 110 using a default sounding reference signal (SRS) resource configuration based at least in part on receiving the DCI before a medium access control (MAC) control element (MAC-CE) selects a subset of uplink TCI states included in an uplink TCI state pool configured for UE 120, etc. In some aspects, such components may include a component for transmitting uplink MIMO communication to base station 110 in combination with the DCI. Figure 2 One or more components of UE 120 are depicted, such as controller / processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, and the like.

[0042] In some aspects, base station 110 may include: means for sending DCI scheduling uplink MIMO communication to UE 120; and means for receiving uplink MIMO communication from UE 120 using a default SRS resource configuration based at least in part on UE receiving the DCI before MAC-CE selects a subset of uplink transmission configuration indicating TCI states included in an uplink TCI state pool configured for UE 120, etc. In some aspects, such means may include combining Figure 2 One or more components of base station 110 are depicted, such as antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller / processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, and the like.

[0043] As mentioned above, Figure 2 Other examples can be found in the Figure 2 The content described is different.

[0044] Figure 3 is a diagram illustrating an example call flow 300 associated with uplink MIMO communications according to various aspects of the present disclosure. Figure 3 As shown, the UE can communicate with the base station through a wireless network (e.g., wireless network 100). In addition, as described herein, the UE and the base station can use beams to communicate with each other. For example, in some cases, the downlink transmission configuration indicator (TCI) state can define the beam according to the downlink transmit beam to be used by the base station and the corresponding downlink receive beam to be used by the UE. Typically, the downlink TCI state can indicate the source reference signal and quasi-colocation (QCL) type to be used for the corresponding beam. For example, the QCL type can correspond to one or more QCL relationships, which indicate how the source reference signal will be quasi-colocated (QCL) with the channel on the beam. If the properties of the channel on which the symbols on one antenna port are conveyed (e.g., the channel on the beam) can be inferred from the channel on which the symbols on another antenna port are conveyed (e.g., the source reference signal), the two antenna ports are called QCL. Examples of QCL relationships that can be bound in the QCL type may include Doppler shift, Doppler spread, average delay, delay spread, spatial reception parameters, etc. Accordingly, the QCL relationship(s) indicated in the TCI state can generally be used to derive the properties of the beam from the properties of the source reference signal.

[0045] In addition, on the uplink, the beam is typically defined based on uplink spatial relationship information indicating the spatial domain transmission filter to be used by the UE for the corresponding uplink communication. Accordingly, in this case, the uplink spatial relationship information may indicate the uplink transmit beam to be used by the UE and the corresponding uplink receive beam to be used by the base station. Additionally or alternatively, an uplink TCI state may be defined for beamformed uplink communications. In such cases, each valid uplink TCI state configuration may include a source reference signal indicating an uplink transmit beam for a target uplink communication (e.g., a target uplink reference signal or a target uplink channel). For example, the source reference signal may be an uplink reference signal (such as a sounding reference signal (SRS)), or a downlink reference signal (such as a synchronization signal block (SSB)), a channel state information reference signal

[0046] (CSI-RS), etc. In addition, the target uplink communication can be a physical random access channel (PRACH), a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), SRS, a demodulation reference signal (DMRS) (e.g., DMRS for PUCCH or PUSCH), etc. In this way, supporting uplink TCI states can enable a unified TCI framework for downlink and uplink communications, can enable the base station to indicate various uplink QCL relationships (e.g., Doppler shift, Doppler spread, average delay, delay spread, etc.) for uplink TCI states, etc. For example, in Figure 3 In the example call flow 300, the example call flow 300 can be used to inform the UE about which uplink TCI state will be activated for a particular uplink communication.

[0047] In particular, if Figure 3As shown in , and as shown by reference numeral 310, a base station may send and a UE may receive radio resource control (RRC) signaling configured for an uplink TCI state pool for the UE. In some aspects, the RRC signaling may include one or more RRC messages configuring an uplink TCI state pool for a specific uplink resource or resource set. For example, the uplink resources associated with the uplink TCI state pool configured by the RRC may generally include one or more time and frequency resources (e.g., resource blocks) that the UE may use to send uplink communications (e.g., uplink reference signals (such as SRS, etc.) or uplink channels (such as PRACH, PUCCH, PUSCH, etc.)). Additionally or alternatively, an uplink resource set associated with the configured uplink TCI state pool may include a set of time and frequency resources (e.g., a set of resource blocks) that the UE may use to send uplink communications. In some aspects, the uplink TCI state pool may include up to 128 candidate uplink TCI states that may be used for corresponding uplink communications. For example, in some aspects, each candidate uplink TCI state included in the uplink TCI state pool configuration may include a source reference signal indicating an uplink transmit beam to be used for a target uplink communication. For example, the source reference signal may include an uplink reference signal (e.g., SRS) or a downlink reference signal (e.g., SSB or CSI-RS), and the target uplink communication may include an uplink reference signal (e.g., SRS), an uplink channel (e.g., PRACH, PUCCH, or PUSCH), an uplink reference signal for an uplink channel (e.g., DMRS for PUCCH or PUSCH), and the like. In addition, in some aspects, an uplink TCI state pool for a specific uplink resource or uplink resource set may be associated with an uplink TCI state identifier space specific to a specific bandwidth portion, a specific component carrier, and / or a UE.

[0048] like Figure 3 As further shown in the figure and indicated by reference numeral 320, the base station may send and the UE may receive a medium access control (MAC) control element (MAC-CE) for selecting a subset of candidate uplink TCI states in the RRC-configured uplink TCI state pool. For example, as described above, the RRC-configured uplink TCI state pool may include up to 128 candidate uplink TCI states for one or more uplink resources or uplink resource sets, and the MAC-CE may include a method for selecting up to 2 from the RRC-configured uplink TCI state pool. NThe MAC-CE may include information of uplink TCI states for uplink transmissions scheduled by the DCI in a three-bit TCI request field, where N is the number of bits that subsequent downlink control information (DCI) may include in a TCI request field to activate a specific uplink TCI state for uplink transmissions scheduled by the DCI. For example, in some aspects, the MAC-CE may select up to eight (8) uplink TCI states from an RRC-configured uplink TCI state pool, which TCI states may be sequentially mapped to eight (8) possible codepoints that the DCI may provide in a three-bit TCI request field for uplink communications scheduled for dynamic or semi-persistent scheduling. Accordingly, as shown in the reference numeral 330, the base station may send and the UE may receive DCI including an uplink TCI codepoint (e.g., in a three-bit uplink TCI request field) that is to be mapped to an uplink TCI state in a subset of the uplink TCI states selected by the MAC-CE.

[0049] like Figure 3 As further shown in the and indicated by reference numeral 340, the UE may perform uplink transmission using an uplink TCI state mapped to an uplink TCI code point included in a DCI that schedules an uplink transmission, which may include an SRS, a PRACH, a PUCCH, a PUSCH, a DMRS for PUCCH, a DMRS for PUSCH, etc. For example, in some aspects, the UE may perform uplink transmission using an uplink transmit beam associated with an uplink TCI state identified by an uplink TCI code point included in the scheduling DCI, and the base station may receive the uplink transmission using an uplink receive beam corresponding to the uplink transmit beam.

[0050] Accordingly, in the case where the base station and the UE are configured to communicate on the uplink using uplink TCI states (e.g., as part of a unified TCI framework for uplink and downlink), RRC signaling configures an uplink TCI state pool including a plurality of candidate uplink TCI states, and MAC-CE is then used to select 2 from the uplink TCI state pool. Nor less uplink TCI states, where N is the number of bits in the DCI for scheduling uplink transmissions for activating a specific uplink TCI state. However, in some cases, the UE may receive a DCI for scheduling uplink transmissions before receiving a MAC-CE that down-selects a candidate uplink TCI state in the RRC-configured uplink TCI state pool. In this case, since the DCI for scheduling the uplink indicates the uplink beam to be used according to the uplink TCI code point, the UE may not be able to clearly determine the uplink beam to be used until the MAC-CE down-selects the candidate uplink TCI state in the RRC-configured uplink TCI state pool to the number that can be mapped to the uplink TCI code point (e.g., eight or less in the case of a three-bit uplink TCI code point).

[0051] Accordingly, some aspects described herein relate to techniques and apparatus for configuring uplink MIMO communications (e.g., PUSCH communications) when an uplink DCI for scheduling uplink MIMO communications includes an uplink TCI code point before a MAC-CE selects a subset of uplink TCI states in an RRC-configured uplink TCI state pool. For example, as further described in detail herein, a UE may be configured with one or more SRS resources and / or SRS resource sets for codebook or non-codebook uplink MIMO communications, and the UE may send uplink MIMO communications using a default SRS resource configuration before a MAC-CE selects a subset of uplink TCI states in an RRC-configured uplink TCI state pool. In this way, the UE may determine various parameters to be used for uplink MIMO communications (e.g., SRS transmissions, PUSCH transmissions, etc.) based on the default SRS resource configuration. For example, the default SRS resource configuration may be used to determine one or more power control parameters to be used for uplink MIMO communication, one or more precoding parameters to be used for uplink MIMO communication, an uplink beam to be used for uplink MIMO communication, etc. In addition, in some aspects, the UE may be configured to map code points included in the scheduling DCI to specific uplink TCI states, SRS triggering states, etc. based at least in part on the number of uplink TCI states included in the RRC-configured uplink TCI state pool, the number of RRC-configured SRS triggering states, etc. In this way, the UE and the base station may determine an explicit mapping between the code points included in the scheduling DCI and the RRC-configured uplink TCI states and / or SRS triggering states without requiring the MAC-CE to select the RRC-configured uplink TCI states and / or SRS triggering states to the number of possible values ​​that can be sequentially mapped to the code points.

[0052] As mentioned above, Figure 3 Other examples can be found in the Figure 3 The content described is different.

[0053] Figure 4 4 is a diagram illustrating an example 400 of default uplink MIMO transmission prior to uplink TCI state activation according to various aspects of the present disclosure. Figure 4 As shown, example 400 includes a UE (e.g., UE 120) communicating with a base station (e.g., base station 110) via a wireless network (e.g., wireless network 100). In some aspects, as described herein, the UE and the base station may communicate on the uplink using beamforming communications. For example, the UE may use an uplink transmit beam when transmitting uplink communications, and the base station may receive uplink communications using an uplink receive beam corresponding to the uplink transmit beam. Typically, the base station may perform uplink beam management to configure, activate, deactivate, or otherwise update the uplink transmit beam and the corresponding uplink receive beam based at least in part on the uplink TCI state. For example, the UE may support beamforming uplink communications using uplink TCI states, and downlink signaling from the base station to the UE may be used to indicate a specific uplink TCI state to be activated and used for uplink communications from the UE to the base station.

[0054] like Figure 4 As shown, and as shown by reference numeral 410, the base station may send and the UE may receive RRC signaling for configuring the uplink TCI state pool. For example, as described above, the RRC signaling may include one or more RRC messages for configuring the uplink TCI state pool, and the uplink TCI state pool includes up to 128 candidate uplink TCI states that can be used for uplink communication. For example, in some aspects, each candidate uplink TCI state included in the uplink TCI state pool configuration may indicate the QCL relationship between the source reference signal and the target uplink communication. For example, the source reference signal may include an uplink reference signal (e.g., SRS) or a downlink reference signal (e.g., SSB or CSI-RS), and the target uplink communication may include an uplink reference signal (e.g., SRS), an uplink channel (e.g., PRACH, PUCCH or PUSCH), an uplink reference signal for an uplink channel (e.g., DMRS for PUCCH or PUSCH), and the like. Accordingly, each uplink TCI state in the RRC-configured uplink TCI state pool can be used to determine various transmission parameters (e.g., power control, precoding, beam information, etc.) to be used for target uplink communications based at least in part on a source reference signal.

[0055] like Figure 4 As further shown in and indicated by reference numeral 420, before the MAC-CE selects a subset of uplink TCI states included in the RRC configured uplink TCI state pool, the base station may send and the UE may receive DCI that schedules uplink MIMO communications. For example, in some aspects, the uplink MIMO communications scheduled by the DCI may include a PUSCH, and the DCI may be associated with an uplink DCI format (e.g., DCI format 0_0 or 0_1) without an uplink TCI request field. Alternatively, the DCI may include an uplink TCI request field, in which case the DCI may include an SRS resource indicator (SRI) and / or a transmit precoder matrix indicator (TPMI) index to indicate a precoder and / or rank information for uplink MIMO communications.

[0056] like Figure 4 As further shown, and indicated by reference numeral 430, the UE may determine a default SRS resource configuration to be used for uplink MIMO communications based at least in part on receiving a DCI scheduling uplink MIMO before the MAC-CE selects a subset of uplink TCI states in the RRC-configured uplink TCI state pool. For example, for codebook-based and non-codebook-based uplink MIMO transmissions, the UE may be configured with one or more SRS resource sets that indicate various communication parameters to be used for SRS transmissions.

[0057] For example, in some aspects, a UE may be configured with multiple SRS resource sets, each of which includes one or more SRS resources. In this case, each SRS resource in the SRS resource set has the same number of ports, and different SRS resource sets may include different numbers of SRS ports and / or different numbers of SRS resources. For example, a first SRS resource set may include four SRS resources, all with four SRS ports, and a second SRS resource set may include two SRS resources, all with two SRS ports. In addition, in the case of non-codebook uplink MIMO transmission, an uplink TCI state may be used to indicate an uplink beam associated with an SRS resource set, and / or an SRI indicating a precoder and / or rank information. In the case of codebook uplink MIMO transmission, an uplink TCI state may similarly indicate an uplink beam associated with an SRS resource set, and in this case, a TPMI index may indicate a precoder and / or rank information.

[0058] Alternatively, in the case where the UE is configured with a single SRS resource set, the SRS resource set may include one or more SRS resources that may have different numbers of SRS ports. For example, the SRS resource set may include one or more SRS resources with two SRS ports, one or more SRS resources with four SRS ports, and so on. In addition, in the case of non-codebook uplink MIMO transmission, the uplink TCI state may similarly indicate an uplink beam associated with the SRS resource, and / or an SRI indicating precoder and / or rank information, or in the case of codebook uplink MIMO transmission, the uplink TCI state may indicate an uplink beam associated with the SRS resource, and a TPMI index indicating precoder and / or rank information.

[0059] Accordingly, in some aspects, the UE may determine a default SRS resource configuration based at least in part on a default SRS resource (e.g., where the UE is configured with a single SRS resource set that may include multiple SRS resources with different parameters) or a default SRS resource set (e.g., where the UE is configured with multiple SRS resource sets, each of which may include one or more SRS resources with the same parameters). For example, in some aspects, the default SRS resource or default SRS resource set may correspond to an SRS resource or SRS resource set with a lowest identifier, a highest identifier, etc. Additionally or alternatively, the default SRS resource or default SRS resource set may be determined based at least in part on a corresponding priority for the SRS resource and / or SRS resource set configured for the UE. For example, in some aspects, the priority may be defined such that an SRS resource or SRS resource set associated with a periodic configuration has the highest priority, an SRS resource or SRS resource set associated with a semi-persistent configuration has the second highest priority, and an SRS resource or SRS resource set associated with an aperiodic configuration has the lowest priority. Alternatively, the priority may be defined such that an SRS resource or SRS resource set associated with an aperiodic configuration has the highest priority, an SRS resource or SRS resource set associated with a semi-persistent configuration has the second highest priority, and an SRS resource or SRS resource set associated with a periodic configuration has the lowest priority. In such a case, where there are multiple SRS resources or multiple SRS resource sets with the same priority, identifiers associated with the multiple SRS resources or SRS resource sets may be used to determine a default SRS resource or SRS resource set.

[0060] In some aspects, the UE may determine a default SRS resource configuration based at least in part on a default SRS resource or SRS resource set. For example, in some aspects, the default SRS resource configuration may include a set of power control parameters to be used for uplink MIMO communication (e.g., a path loss reference signal, a P0 parameter reflecting a target signal to interference and noise ratio (SINR) for uplink MIMO communication, an α parameter representing a fractional power control factor, a closed-loop index that may indicate power control parameters for different uplink panels, etc.). Accordingly, the UE may determine the power control parameters to be used for uplink MIMO communication (which may include PUSCH transmissions scheduled by DCI) based at least in part on the power control parameters associated with the default SRS resource configuration. For example, in the case of codebook-based MIMO transmission, each SRS resource in an SRS resource set may have a different set of power control parameters, whereby the power control parameters for codebook-based MIMO transmission may be determined based on the power control parameters associated with the default SRS resources in the SRS resource set. Similarly, in the case where the UE is configured with multiple SRS resource sets for codebook-based or non-codebook-based MIMO transmission, each SRS resource set can be associated with a different set of power control parameters, whereby the power control parameters for codebook-based or non-codebook-based MIMO transmission can be determined based on the power control parameters associated with a default SRS resource set among the multiple SRS resource sets.

[0061] In addition, in some aspects, the default SRS resource configuration can be used to determine additional transmission parameters for uplink MIMO communication. For example, in some aspects, the UE can determine one or more precoding parameters based at least in part on the precoding parameters associated with the default SRS resource configuration (e.g., the maximum number of SRS ports, the number of SRS resources, the maximum rank associated with the SRS resource set), and the like. In this way, the UE can determine the precoding parameters (e.g., SRI or TPMI) to be used for uplink MIMO communication (e.g., according to the bit width and code point mapping of the SRI or TPMI in the field of the DCI). In addition, in some aspects, the default SRS resource configuration can be used to determine the uplink beam to be used for uplink MIMO communication. For example, in some aspects, the beam associated with the default SRS resource configuration can be used as an uplink beam for uplink MIMO communication.

[0062] like Figure 4As further shown, and indicated by reference numeral 440, the UE may determine a mapping between a code point included in a DCI for scheduling uplink MIMO communication and a target uplink MIMO communication. For example, in some cases, the DCI may include a code point in an SRS request field to indicate an SRS triggering state to be activated (e.g., to schedule SRS transmission using the indicated SRS triggering state). Additionally or alternatively, in some cases, the DCI may include a code point in an uplink TCI request field to indicate a target uplink MIMO communication. Accordingly, as described herein, because the scheduling DCI is received before the MAC-CE selects a subset of the RRC-configured SRS triggering states and / or a subset of the RRC-configured uplink TCI states, the UE may determine a direct mapping from a code point in the scheduling DCI to one of the RRC-configured SRS triggering states and / or the RRC-configured uplink TCI states.

[0063] For example, in the case where the scheduling DCI includes a code point in the SRS request field having N bits, when the number of trigger states configured by RRC is less than or equal to 2 N When -1, the codepoint can directly indicate the SRS triggering status (in the absence of any MAC-CE subset selection). In particular, a codepoint (e.g., "000") can indicate that no SRS request is triggered, which leaves 2 N -1 possible codepoint that can be provided in the SRS request field to trigger SRS transmission. Accordingly, when the number of SRS triggering states configured by RRC is less than or equal to 2 N -1, the N bits in the SRS request field can unambiguously identify one of the RRC-configured SRS triggering states without any MAC-CE subset selection. Alternatively, when the number of RRC-configured SRS triggering states is greater than 2 N -1 case, the first 2 N - 1 RRC configured SRS triggering state may be mapped to an N-bit SRS request field, which may then directly indicate the SRS triggering state to be activated without any MAC-CE subset selection.

[0064] Similarly, in the case where the scheduling DCI includes a codepoint in the uplink TCI request field having N bits, when the number of trigger states configured by RRC is less than or equal to 2 N In particular, when the number of uplink TCI states configured by RRC is less than or equal to 2, the codepoint can directly indicate the uplink TCI state (and therefore the target uplink MIMO communication) without any MAC-CE subset selection. NBecause the N bits in the uplink TCI request field can have a maximum of 2 N The N bits in the Uplink TCI Request field can unambiguously identify one of the RRC-configured uplink TCI states without any MAC-CE subset selection. Alternatively, when the number of RRC-configured uplink TCI states is greater than 2, the N bits in the Uplink TCI Request field can unambiguously identify one of the RRC-configured uplink TCI states without any MAC-CE subset selection. N In the case of the first 2 N The uplink TCI states configured by each RRC may be mapped to an N-bit uplink TCI request field, which may then directly indicate the uplink TCI state to be activated without any MAC-CE subset selection.

[0065] like Figure 4As further shown, and indicated by reference numeral 450, the UE and the base station may transmit and receive uplink MIMO communications using a default SRS resource configuration based at least in part on a code point included in a DCI that schedules uplink MIMO communications. For example, in some aspects, the UE may use a code point included in the scheduling DCI to determine an SRS trigger state to be activated, determine a target uplink MIMO communication, and the like, and the default SRS resource configuration may be used to determine power control parameters, precoding parameters, beam parameters, and the like for uplink MIMO communications. Additionally or alternatively, in some aspects, power control parameters for uplink MIMO communications may be determined based at least in part on an uplink TCI state (e.g., an uplink TCI state mapped to a code point included in the scheduling DCI). For example, in some aspects, RRC signaling that configures an uplink TCI state pool may further configure one or more power control parameters (e.g., a path loss reference signal, a P0 parameter, an alpha parameter, a closed loop index identifier, and the like) for each uplink TCI state. In this case, the power control parameters may be configured simultaneously by changing, updating or otherwise indicating the uplink TCI state to be used for uplink MIMO communication. Additionally or alternatively, the power control parameters may be configured via separate signaling. For example, in some aspects, multiple open-loop power control parameters may be configured via RRC signaling, and the DCI for scheduling the PUSCH may indicate the open-loop power control parameters to be used among the multiple RRC-configured open-loop power control parameters. Additionally or alternatively, the power control parameters may be configured via RRC signaling, for a PUCCH group or an SRS resource set, and the MAC-CE may be used to update the power control parameters for the PUCCH group or the SRS resource set. In this way, the uplink TCI state may be used to indicate uplink MIMO communication (e.g., SRS, PUCCH, PUSCH, etc.), and different techniques may be used to update the power control parameters for uplink MIMO communication (e.g., relative to the power control parameters determined from the default SRS resource configuration).

[0066] As mentioned above, Figure 4 Other examples can be found in the Figure 4 The content described is different.

[0067] Figure 5 5 is a diagram illustrating an example process 500, for example, performed by a UE, according to various aspects of the present disclosure. Example process 500 is an example in which a UE (eg, UE 120, etc.) performs operations associated with default uplink MIMO transmission prior to uplink TCI state activation.

[0068] like Figure 5As shown, in some aspects, process 500 may include receiving DCI scheduling uplink MIMO communications from a base station (block 510). For example, as described above, a UE may receive (e.g., using antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, controller / processor 280, memory 282, etc.) DCI scheduling uplink MIMO communications from a base station.

[0069] like Figure 5 As further shown, in some aspects, process 500 may include sending uplink MIMO communications to a base station using a default SRS resource configuration based at least in part on receiving DCI before the MAC-CE selects a subset of uplink TCI states included in a pool of uplink TCI states configured for the UE (block 520). For example, as described above, the UE may send (e.g., using controller / processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252, etc.) uplink MIMO communications to a base station using a default SRS resource configuration based at least in part on receiving DCI before the MAC-CE selects a subset of uplink TCI states included in a pool of uplink TCI states configured for the UE.

[0070] Process 500 may include additional aspects, such as any single aspect or any combination of aspects described below and / or described in conjunction with one or more other processes described elsewhere herein.

[0071] In a first aspect, a default SRS resource configuration for uplink MIMO communications includes one or more power control parameters associated with one or more of a default SRS resource or a set of default SRS resources.

[0072] In a second aspect, alone or in combination with the first aspect, a default SRS resource configuration for uplink MIMO communication comprises one or more precoding parameters associated with one or more of a default SRS resource or a default SRS resource set.

[0073] In a third aspect, alone or in combination with one or more of the first and second aspects, a default SRS resource configuration for uplink MIMO communication comprises an indication of an uplink transmit beam associated with one or more of a default SRS resource or a default SRS resource set.

[0074] In a fourth aspect, alone or in combination with one or more of the first to third aspects, the default SRS resource configuration is determined based at least in part on an identifier associated with one or more SRS resources or one or more SRS resource sets configured for the UE.

[0075] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, a default SRS resource configuration is determined based at least in part on a priority associated with one or more SRS resources or one or more SRS resource sets configured for the UE.

[0076] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, a DCI scheduling uplink MIMO communication is associated with a DCI format without an uplink TCI request field.

[0077] In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, the DCI scheduling uplink MIMO communication includes an uplink TCI request field indicating an uplink TCI state code point associated with the uplink MIMO communication.

[0078] In an eighth aspect, alone or in combination with one or more of the first to seventh aspects, the DCI for scheduling uplink MIMO communication indicates one or more of the SRI or TPMI for uplink MIMO communication based at least in part on the uplink MIMO communication having a codebook-based configuration.

[0079] In the ninth aspect, alone or in combination with one or more of the first to eighth aspects, the DCI for scheduling uplink MIMO communication includes a code point having N bits, when the number of SRS triggering states in the set of SRS triggering states configured for the UE is 2 N When -1 or less, the code point is mapped to an SRS triggering state in the set of SRS triggering states.

[0080] In the tenth aspect, alone or in combination with one or more of the first to ninth aspects, the DCI for scheduling uplink MIMO communication includes a code point having N bits, when the number of SRS triggering states in the set of SRS triggering states configured for the UE is greater than 2 N -1, the code point is mapped to the first 2 in the set of SRS trigger states N - One of 1 SRS triggering states.

[0081] In the eleventh aspect, alone or in combination with one or more of the first to tenth aspects, the DCI for scheduling uplink MIMO communication includes a code point having N bits, when the number of uplink TCI states included in the uplink TCI state pool configured for the UE is 2 N or less, the code point is mapped to one of the uplink TCI states included in the uplink TCI state pool.

[0082] In the twelfth aspect, alone or in combination with one or more of the first to eleventh aspects, the DCI for scheduling uplink MIMO communication includes a code point having N bits, when the number of uplink TCI states included in the uplink TCI state pool configured for the UE is greater than 2 N When the code point is mapped to the first 2 N One of the uplink TCI states.

[0083] In a thirteenth aspect, either alone or in combination with one or more of the first to twelfth aspects, uplink MIMO communications are transmitted using one or more power control parameters associated with an uplink TCI state code point indicated in a DCI scheduling uplink MIMO communications.

[0084] In the fourteenth aspect, alone or in combination with one or more of the first to thirteenth aspects, when the uplink MIMO communication is PUSCH, the uplink MIMO communication is sent using one or more power control parameters indicated in the DCI that schedules the uplink MIMO communication, or, when the uplink MIMO communication is PUCCH or SRS, the uplink MIMO communication is sent using one or more power control parameters indicated in the MAC-CE.

[0085] Although Figure 5 Example blocks of process 500 are shown, but in some aspects, process 500 may include Figure 5 Additional blocks, fewer blocks, different blocks, or differently arranged blocks may be included than those depicted in the process 500. Additionally or alternatively, two or more blocks in process 500 may be performed in parallel.

[0086] Figure 6 6 is a diagram illustrating an example process 600, for example, performed by a base station, according to various aspects of the present disclosure. Example process 600 is an example in which a base station (eg, base station 110, etc.) performs operations associated with default uplink MIMO transmission prior to uplink TCI state activation.

[0087] like Figure 6 As shown, in some aspects, process 600 may include sending DCI scheduling uplink MIMO communications to the UE (block 610). For example, as described above, the base station may send (e.g., using controller / processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, etc.) DCI scheduling uplink MIMO communications to the UE.

[0088] like Figure 6As further shown, in some aspects, process 600 may include receiving uplink MIMO communications from the UE using a default SRS resource configuration based at least in part on the UE receiving DCI before the MAC-CE selects a subset of uplink TCI states included in a pool of uplink TCI states configured for the UE (block 620). For example, as described above, the base station may receive (e.g., using antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller / processor 240, etc.) uplink MIMO communications from the UE using a default SRS resource configuration based at least in part on the UE receiving DCI before the MAC-CE selects a subset of uplink TCI states included in a pool of uplink TCI states configured for the UE.

[0089] Process 600 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in combination with one or more other processes described elsewhere herein.

[0090] In a first aspect, a default SRS resource configuration for uplink MIMO communications includes one or more power control parameters associated with one or more of a default SRS resource or a set of default SRS resources.

[0091] In a second aspect, alone or in combination with the first aspect, a default SRS resource configuration for uplink MIMO communication comprises one or more precoding parameters associated with one or more of a default SRS resource or a default SRS resource set.

[0092] In a third aspect, alone or in combination with one or more of the first and second aspects, a default SRS resource configuration for uplink MIMO communication comprises an indication of an uplink transmit beam associated with one or more of a default SRS resource or a default SRS resource set.

[0093] In a fourth aspect, alone or in combination with one or more of the first to third aspects, the default SRS resource configuration is determined based at least in part on an identifier associated with one or more SRS resources or one or more SRS resource sets configured for the UE.

[0094] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, a default SRS resource configuration is determined based at least in part on a priority associated with one or more SRS resources or one or more SRS resource sets configured for the UE.

[0095] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, a DCI scheduling uplink MIMO communication is associated with a DCI format without an uplink TCI request field.

[0096] In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, the DCI scheduling uplink MIMO communication includes an uplink TCI request field indicating an uplink TCI state code point associated with the uplink MIMO communication.

[0097] In an eighth aspect, alone or in combination with one or more of the first to seventh aspects, the DCI for scheduling uplink MIMO communication indicates one or more of the SRI or TPMI for uplink MIMO communication based at least in part on the uplink MIMO communication having a codebook-based configuration.

[0098] In the ninth aspect, alone or in combination with one or more of the first to eighth aspects, the DCI for scheduling uplink MIMO communication includes a code point having N bits, when the number of SRS triggering states in the set of SRS triggering states configured for the UE is 2 N When -1 or less, the code point is mapped to an SRS triggering state in the set of SRS triggering states.

[0099] In the tenth aspect, alone or in combination with one or more of the first to ninth aspects, the DCI for scheduling uplink MIMO communication includes a code point having N bits, when the number of SRS triggering states in the set of SRS triggering states configured for the UE is greater than 2 N -1, the code point is mapped to the first 2 in the set of SRS trigger states N - One of 1 SRS triggering states.

[0100] In the eleventh aspect, alone or in combination with one or more of the first to tenth aspects, the DCI for scheduling uplink MIMO communication includes a code point having N bits, when the number of uplink TCI states included in the uplink TCI state pool configured for the UE is 2 N or less, the code point is mapped to one of the uplink TCI states included in the uplink TCI state pool.

[0101] In the twelfth aspect, alone or in combination with one or more of the first to eleventh aspects, the DCI for scheduling uplink MIMO communication includes a code point having N bits, when the number of uplink TCI states included in the uplink TCI state pool configured for the UE is greater than 2 N When the code point is mapped to the first 2N One of the uplink TCI states.

[0102] In a thirteenth aspect, either alone or in combination with one or more of the first to twelfth aspects, uplink MIMO communications are transmitted using one or more power control parameters associated with an uplink TCI state code point indicated in a DCI scheduling uplink MIMO communications.

[0103] In the fourteenth aspect, alone or in combination with one or more of the first to thirteenth aspects, when the uplink MIMO communication is PUSCH, the uplink MIMO communication is sent using one or more power control parameters indicated in the DCI that schedules the uplink MIMO communication, or, when the uplink MIMO communication is PUCCH or SRS, the uplink MIMO communication is sent using one or more power control parameters indicated in the MAC-CE.

[0104] Although Figure 6 Example blocks of process 600 are shown, but in some aspects, process 600 may include Figure 6 Additional blocks, fewer blocks, different blocks, or differently arranged blocks may be included than those depicted in the process 600. Additionally or alternatively, two or more blocks in process 600 may be performed in parallel.

[0105] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the various aspects.

[0106] The term "component" as used herein is intended to be broadly interpreted as hardware, firmware, and / or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, and / or a combination of hardware and software.

[0107] As used herein, satisfying a threshold may refer to a value being greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, not equal to a threshold, etc., depending on the context.

[0108] It will be apparent that the systems and / or methods described herein may be implemented in various forms of hardware, firmware, and / or combinations of hardware and software. The actual dedicated control hardware or software code used to implement the systems and / or methods is not limited in these respects. Thus, the operation and behavior of the systems and / or methods are described herein without reference to specific software code—it should be understood that software and hardware may be designed to implement the systems and / or methods based, at least in part, on the description herein.

[0109] Although the specific combination of features is set forth in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, multiple features in these features can be combined in a manner that is not specifically set forth in the claims and / or is not specifically disclosed in the specification. Although each dependent claim listed below can be directly subordinate to only one claim, the disclosure of various aspects includes the combination of each dependent claim and each other claim in the claim set. The phrase "at least one" related to the list of items refers to any combination of those items, including a single member. As an example, "at least one of a, b, or c" is intended to cover a, b, c, ab, ac, bc, and abc and any combination with multiple identical elements (for example, aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc or any other arrangement of a, b, and c).

[0110] Unless explicitly described, any element, action, or instruction used herein should not be interpreted as critical or necessary. In addition, the articles "a" and "an" used herein are intended to include one or more items and can be used interchangeably with "one or more". In addition, the terms "set" and "group" used herein are intended to include one or more items (e.g., related items, unrelated items, combinations of related and unrelated items, etc.), and can be used interchangeably with "one or more". In the case of only intending to include one item, the phrase "only one" or similar language is used. In addition, the terms "has", "have", "having", etc. used herein are intended to be open terms. In addition, unless otherwise explicitly stated, the phrase "based on" is intended to represent "based at least in part on".

Claims

1. A method of wireless communication performed by a user equipment UE, comprising: receiving downlink control information DCI for scheduling uplink multiple-input multiple-output MIMO communication from a network node; as well as sending the uplink MIMO communication to the network node using a default sounding reference signal (SRS) resource configuration based at least in part on receiving the DCI before a medium access control element MAC-CE selects a subset of uplink TCI states included in an uplink transmission configuration indication (TCI) state pool configured for the UE, wherein the uplink TCI state associated with the uplink beam transmitting the uplink MIMO communication is determined based on an explicit mapping between the code points included in the DCI and the uplink TCI states in the uplink TCI state pool, and the explicit mapping is determined at least in part based on the number of uplink TCI states included in the uplink TCI state pool.

2. The method of claim 1, wherein the default SRS resource configuration for the uplink MIMO communication comprises one or more power control parameters associated with one or more of a default SRS resource or a default SRS resource set.

3. The method of claim 1, wherein the default SRS resource configuration for the uplink MIMO communication comprises one or more precoding parameters associated with one or more of a default SRS resource or a default SRS resource set.

4. The method of claim 1, wherein the default SRS resource configuration for the uplink MIMO communication comprises an indication of an uplink transmit beam associated with one or more of a default SRS resource or a default SRS resource set. 5 . The method of claim 1 , wherein the default SRS resource configuration is determined based at least in part on an identifier associated with one or more SRS resources or one or more SRS resource sets configured for the UE. 6 . The method of claim 1 , wherein the default SRS resource configuration is determined based at least in part on a priority associated with one or more SRS resources or one or more SRS resource sets configured for the UE.

7. The method of claim 1, wherein the DCI scheduling the uplink MIMO communication is associated with a DCI format without an uplink TCI request field.

8. The method of claim 1, wherein the DCI scheduling the uplink MIMO communication comprises an uplink TCI request field indicating an uplink TCI state code point associated with the uplink MIMO communication.

9. The method of claim 1 , wherein the DCI scheduling the uplink MIMO communication indicates one or more of an SRS resource indicator (SRI) or a transmit precoder matrix indicator (TPMI) for the uplink MIMO communication based at least in part on the uplink MIMO communication having a codebook-based configuration.

10. The method of claim 1, wherein the DCI for scheduling the uplink MIMO communication comprises a code point having N bits, and when the number of SRS triggering states in the set of SRS triggering states configured for the UE is 2 N When -1 or less, the code point is mapped to an SRS triggering state in the set of SRS triggering states.

11. The method of claim 1 , wherein the DCI for scheduling the uplink MIMO communication comprises a code point having N bits, and when the number of SRS triggering states in the set of SRS triggering states configured for the UE is greater than 2 N -1, the code point is mapped to the first 2 in the set of SRS trigger states N - One of 1 SRS triggering states.

12. The method of claim 1, wherein the DCI for scheduling the uplink MIMO communication comprises a code point having N bits, when the number of uplink TCI states included in the uplink TCI state pool configured for the UE is 2 N or less, the code point is mapped to one of the uplink TCI states included in the uplink TCI state pool.

13. The method of claim 1, wherein the DCI for scheduling the uplink MIMO communication comprises a code point having N bits, when the number of uplink TCI states included in the uplink TCI state pool configured for the UE is greater than 2. N When the code point is mapped to the first 2 N One of the uplink TCI states.

14. The method of claim 1, wherein the uplink MIMO communication is transmitted using one or more power control parameters associated with an uplink TCI state code point indicated in the DCI scheduling the uplink MIMO communication.

15. The method of claim 1, wherein when the uplink MIMO communication is a physical uplink shared channel (PUSCH), the uplink MIMO communication is sent using one or more power control parameters indicated in the DCI that schedules the uplink MIMO communication, or, when the uplink MIMO communication is a physical uplink control channel (PUCCH) or SRS, the uplink MIMO communication is sent using one or more power control parameters indicated in the MAC-CE.

16. A method of wireless communication performed by a base station, comprising: Sending downlink control information DCI for scheduling uplink multiple-input multiple-output MIMO communication to user equipment UE; as well as receiving the uplink MIMO communication from the UE using a default sounding reference signal (SRS) resource configuration based at least in part on the UE receiving the DCI before a medium access control element MAC-CE selects a subset of uplink TCI states included in an uplink transmission configuration indication (TCI) state pool configured for the UE, wherein the uplink TCI state associated with the uplink beam transmitting the uplink MIMO communication is determined based on an explicit mapping between the code points included in the DCI and the uplink TCI states in the uplink TCI state pool, and the explicit mapping is determined at least in part based on the number of uplink TCI states included in the uplink TCI state pool.

17. The method of claim 16, wherein the default SRS resource configuration for the uplink MIMO communication comprises one or more power control parameters associated with one or more of a default SRS resource or a default SRS resource set.

18. The method of claim 16, wherein the default SRS resource configuration for the uplink MIMO communication comprises one or more precoding parameters associated with one or more of a default SRS resource or a default SRS resource set.

19. The method of claim 16, wherein the default SRS resource configuration for the uplink MIMO communication comprises an indication of an uplink transmit beam associated with one or more of a default SRS resource or a default SRS resource set.

20. The method of claim 16, wherein the default SRS resource configuration is determined based at least in part on an identifier associated with one or more SRS resources or one or more SRS resource sets configured for the UE.

21. The method of claim 16, wherein the default SRS resource configuration is determined based at least in part on a priority associated with one or more SRS resources or one or more SRS resource sets configured for the UE.

22. The method of claim 16, wherein the DCI scheduling the uplink MIMO communication is associated with a DCI format without an uplink TCI request field.

23. The method of claim 16, wherein the DCI scheduling the uplink MIMO communication includes an uplink TCI request field indicating an uplink TCI state code point associated with the uplink MIMO communication.

24. The method of claim 16, wherein the DCI scheduling the uplink MIMO communication indicates one or more of an SRS resource indicator (SRI) or a transmit precoder matrix indicator (TPMI) for the uplink MIMO communication based at least in part on the uplink MIMO communication having a codebook-based configuration.

25. The method of claim 16, wherein the DCI for scheduling the uplink MIMO communication comprises a code point having N bits, and when the number of SRS triggering states in the set of SRS triggering states configured for the UE is 2 N When -1 or less, the code point is mapped to an SRS triggering state in the set of SRS triggering states.

26. The method of claim 16, wherein the DCI for scheduling the uplink MIMO communication comprises a code point having N bits, and when the number of SRS triggering states in the set of SRS triggering states configured for the UE is greater than 2 N -1, the code point is mapped to the first 2 in the set of SRS trigger states N - One of 1 SRS triggering states.

27. The method of claim 16, wherein the DCI for scheduling the uplink MIMO communication comprises a code point having N bits, when the number of uplink TCI states included in the uplink TCI state pool configured for the UE is 2 N or less, the code point is mapped to one of the uplink TCI states included in the uplink TCI state pool.

28. The method of claim 16, wherein the DCI for scheduling the uplink MIMO communication comprises a code point having N bits, when the number of uplink TCI states included in the uplink TCI state pool configured for the UE is greater than 2. N When the code point is mapped to the first 2 N One of the uplink TCI states.

29. The method of claim 16, wherein the uplink MIMO communication is transmitted using one or more power control parameters associated with an uplink TCI state code point indicated in the DCI scheduling the uplink MIMO communication.

30. A method as claimed in claim 16, wherein when the uplink MIMO communication is a physical uplink shared channel PUSCH, the uplink MIMO communication is sent using one or more power control parameters indicated in the DCI that schedules the uplink MIMO communication, or, when the uplink MIMO communication is a physical uplink control channel PUCCH or SRS, the uplink MIMO communication is sent using one or more power control parameters indicated in the MAC-CE.

31. A user equipment UE for wireless communication, comprising: Memory; as well as one or more processors, the one or more processors being operably coupled to the memory, the memory and the one or more processors being configured to: receiving downlink control information DCI for scheduling uplink multiple-input multiple-output MIMO communication from a network node; as well as sending the uplink MIMO communication to the network node using a default sounding reference signal resource configuration based at least in part on receiving the DCI before a medium access control element MAC-CE selects a subset of uplink TCI states included in an uplink transmission configuration indication TCI state pool configured for the UE, wherein the uplink TCI state associated with the uplink beam transmitting the uplink MIMO communication is determined based on an explicit mapping between the code points included in the DCI and the uplink TCI states in the uplink TCI state pool, and the explicit mapping is determined at least in part based on the number of uplink TCI states included in the uplink TCI state pool.

32. A network node for wireless communication, comprising: Memory; as well as one or more processors, the one or more processors being operably coupled to the memory, the memory and the one or more processors being configured to: Sending downlink control information DCI for scheduling uplink multiple-input multiple-output MIMO communication to user equipment UE; as well as receiving the uplink MIMO communication from the UE using a default sounding reference signal resource configuration based at least in part on the UE receiving the DCI before a medium access control MAC control element MAC-CE selects a subset of uplink TCI states included in an uplink transmission configuration indication TCI state pool configured for the UE, wherein the uplink TCI state associated with the uplink beam transmitting the uplink MIMO communication is determined based on an explicit mapping between the code points included in the DCI and the uplink TCI states in the uplink TCI state pool, and the explicit mapping is determined at least in part based on the number of uplink TCI states included in the uplink TCI state pool.

33. A non-transitory computer readable medium storing one or more instructions for wireless communication, the one or more instructions comprising: One or more instructions, when executed by one or more processors of a user equipment UE, the one or more instructions cause the one or more processors to: receiving downlink control information DCI for scheduling uplink multiple-input multiple-output MIMO communication from a network node; as well as sending the uplink MIMO communication to the network node using a default sounding reference signal resource configuration based at least in part on receiving the DCI before a medium access control element MAC-CE selects a subset of uplink TCI states included in an uplink transmission configuration indication TCI state pool configured for the UE, wherein the uplink TCI state associated with the uplink beam transmitting the uplink MIMO communication is determined based on an explicit mapping between the code points included in the DCI and the uplink TCI states in the uplink TCI state pool, and the explicit mapping is determined at least in part based on the number of uplink TCI states included in the uplink TCI state pool.

34. A non-transitory computer readable medium storing one or more instructions for wireless communication, the one or more instructions comprising: One or more instructions that, when executed by one or more processors of a network node, cause the one or more processors to: Sending downlink control information DCI for scheduling uplink multiple-input multiple-output MIMO communication to user equipment UE; as well as receiving the uplink MIMO communication from the UE using a default sounding reference signal resource configuration based at least in part on the UE receiving the DCI before a medium access control element MAC-CE selects a subset of uplink TCI states included in an uplink transmission configuration indication TCI state pool configured for the UE, wherein the uplink TCI state associated with the uplink beam transmitting the uplink MIMO communication is determined based on an explicit mapping between the code points included in the DCI and the uplink TCI states in the uplink TCI state pool, and the explicit mapping is determined at least in part based on the number of uplink TCI states included in the uplink TCI state pool.

35. An apparatus for wireless communication, comprising: means for receiving downlink control information DCI scheduling uplink multiple-input multiple-output MIMO communications from a network node; as well as means for transmitting the uplink MIMO communication to the network node using a default sounding reference signal resource configuration based at least in part on receiving the DCI before a medium access control MAC control element MAC-CE selects a subset of uplink TCI states included in an uplink transmission configuration indication TCI state pool configured for the apparatus, wherein the uplink TCI state associated with the uplink beam transmitting the uplink MIMO communication is determined based on an explicit mapping between the code points included in the DCI and the uplink TCI states in the uplink TCI state pool, and the explicit mapping is determined at least in part based on the number of uplink TCI states included in the uplink TCI state pool.

36. An apparatus for wireless communication, comprising: A component for sending downlink control information DCI for scheduling uplink multiple-input multiple-output MIMO communication to a user equipment UE; as well as means for receiving the uplink MIMO communication from the UE using a default sounding reference signal resource configuration based at least in part on the UE receiving the DCI before a medium access control element MAC-CE selects a subset of uplink TCI states included in an uplink transmission configuration indication TCI state pool configured for the UE, wherein the uplink TCI state associated with the uplink beam transmitting the uplink MIMO communication is determined based on an explicit mapping between the code points included in the DCI and the uplink TCI states in the uplink TCI state pool, and the explicit mapping is determined at least in part based on the number of uplink TCI states included in the uplink TCI state pool.

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