Determine the default uplink (UL) transmission configuration indicator (TCI) state

Abstract

Certain aspects of the present disclosure provide techniques for determining default parameters to use in the absence of a signaled uplink transmission configuration indicator (TCI) state for uplink transmission. In some cases, a UE may determine, based on one or more rules, at least one of a default uplink beam or a default path loss reference signal (PL RS) to use for uplink transmission in the absence of a signaled uplink transmission configuration indicator (TCI) state for uplink transmission, and send an uplink transmission based on the determination.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. application No. 17 / 126,820 filed on December 18, 2020, which claims the benefit of U.S. provisional patent application serial No. 62 / 951,721, entitled “Determining a Default Uplink (UL) Transmission Configuration Indicator (TCI) State,” filed on December 20, 2019, which is assigned to the assignee of this application, and the contents of the above-mentioned application are hereby incorporated by reference in their entirety. Technical Field

[0003] Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for determining a transmission configuration indicator (TCI) state for uplink transmissions performed by a user equipment (UE). Background Art

[0004] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. These wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple-access systems include the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) system, the Advanced LTE (LTE-A) system, the Code Division Multiple Access (CDMA) system, the Time Division Multiple Access (TDMA) system, the Frequency Division Multiple Access (FDMA) system, the Orthogonal Frequency Division Multiple Access (OFDMA) system, the Single Carrier Frequency Division Multiple Access (SC-FDMA) system, and the Time Division Synchronous Code Division Multiple Access (TD-SCDMA) system, to name a few.

[0005] In some examples, a wireless multiple access communication system may include multiple base stations (BSs), each base station capable of simultaneously supporting communication for multiple communication devices (also referred to as user equipment (UE)). In an LTE or LTE-A network, a set of one or more base stations may define an evolved node B (eNB). In other examples (e.g., in next generation, new radio (NR) or 5G networks), a wireless multiple access communication system may include multiple distributed units (DUs) (e.g., edge units (EUs), edge nodes (ENs), radio heads (RHs), smart radio heads (SRHs), transmit receive points (TRPs), etc.) communicating with multiple central units (CUs) (e.g., central nodes (CNs), access node controllers (ANCs), etc.), where the set of one or more DUs communicating with the CUs may define an access node (e.g., which may be referred to as a BS, 5G NB, next generation node B (gNB or gNodeB), transmit receive point (TRP), etc.). A BS or DU may communicate with a set of UEs on downlink channels (eg, for transmissions from the BS or DU to the UEs) and uplink channels (eg, for transmissions from the UEs to the BS or DU).

[0006] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at a city, country, region, and even global level. NR (e.g., New Radio or 5G) is an example of an emerging telecommunication standard. NR is a set of enhancements to the LTE mobile standard released by 3GPP. NR is designed to better support mobile broadband Internet access by improving spectrum efficiency, reducing costs, improving services, utilizing new spectrum, and better integrating with other open standards using OFDMA with cyclic prefix (CP) on the downlink (DL) and uplink (UL). To this end, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

[0007] However, as demand for mobile broadband access continues to grow, there is a need for further improvements to NR and LTE technologies. Preferably, these improvements should also apply to other multiple access technologies and the telecommunication standards that employ them. Summary of the Invention

[0008] The systems, methods, and devices of the present disclosure each have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of the disclosure as expressed by the claims that follow, some features will now be briefly discussed. After considering this discussion, and particularly after reading the section entitled "Detailed Description," one will understand how the features of the present disclosure provide advantages, including improved communication between access points and stations in a wireless network.

[0009] Certain aspects of the present disclosure relate to a method for wireless communications by a user equipment (UE). Generally speaking, the method includes determining, based on one or more rules, at least one of a default uplink beam or a default path loss reference signal (PL RS) to use for an uplink transmission in the absence of a signaled uplink transmission configuration indicator (TCI) state for the uplink transmission; and sending the uplink transmission based on the determination.

[0010] Certain aspects of the present disclosure relate to a method for wireless communications by a network entity. Generally speaking, the method includes determining, based on one or more rules, at least one of a default uplink beam or a default path loss reference signal (PL RS) for a user equipment (UE) to use for receiving an uplink transmission in the absence of a signaled uplink transmission configuration indicator (TCI) state for the uplink transmission; and processing the uplink transmission based on the determination.

[0011] Aspects of the present disclosure also provide various means, units, and computer-readable media including instructions for performing the operations described herein.

[0012] To accomplish the foregoing and related ends, one or more aspects include the features hereinafter fully described and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail certain illustrative features of one or more aspects. However, these features are indicative of only a few of the various ways in which the principles of the various aspects may be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order that the above-mentioned features of the present disclosure may be understood in detail, a more particular description (briefly summarized above) may be made by reference to various aspects, some of which are illustrated in the accompanying drawings. It should be noted, however, that the drawings illustrate only certain typical aspects of the present disclosure and are not therefore to be considered limiting of its scope, as the description may admit to other equally effective aspects.

[0014] Figure 1 is a block diagram conceptually illustrating an example telecommunications system in accordance with certain aspects of the present disclosure.

[0015] Figure 2 is a block diagram illustrating an example for implementing a communication protocol stack in an example RAN architecture, in accordance with certain aspects of the present disclosure.

[0016] Figure 3 is a block diagram conceptually illustrating designs of example base stations (BSs) and user equipment (UEs) in accordance with certain aspects of the present disclosure.

[0017] Figure 4 An example of a frame format for a telecommunications system is shown, in accordance with certain aspects of the present disclosure.

[0018] Figure 5

[0014] Example operations for wireless communications by a UE are illustrated, in accordance with certain aspects of the present disclosure.

[0019] Figure 6

[0014] Example operations for wireless communications by a base station are illustrated, in accordance with certain aspects of the present disclosure.

[0020] Figure 7 A communication device according to aspects of the present disclosure is shown, which may include various components configured to perform operations for the techniques disclosed herein.

[0021] Figure 8 A communication device according to aspects of the present disclosure is shown, which may include various components configured to perform operations for the techniques disclosed herein.

[0022] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation. DETAILED DESCRIPTION

[0023] Various aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for configuring a default beam when an uplink TCI status is not indicated to a user equipment.

[0024] The following description provides examples and does not limit the scope, applicability, or examples set forth in the claims. Changes may be made to the functions and arrangements of the elements discussed without departing from the scope of this disclosure. Various examples may omit, replace, or add various processes or components as appropriate. For example, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. In addition, features described with respect to some examples may be combined in some other examples. For example, a device may be implemented or a method may be implemented using any number of the aspects set forth herein. In addition, the scope of this disclosure is intended to cover such devices or methods implemented using other structures, functions, or structures and functions in addition to or different from the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of the claims. 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.

[0025] The techniques described herein can be used for various wireless communication technologies, such as LTE, CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other networks. The terms "network" and "system" are often used interchangeably. A CDMA network can implement radio technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, and the like. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000 covers the IS-2000, IS-95, and IS-856 standards. A TDMA network can implement radio technologies such as Global System for Mobile Communications (GSM). An OFDMA network can implement radio technologies such as NR (e.g., 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, and the like. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS).

[0026] New Radio (NR) is an emerging wireless communication technology under development in conjunction with the 5G Technology Forum (5GTF). 3GPP Long Term Evolution (LTE) and Advanced LTE (LTE-A) are versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). cdma2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). The techniques described herein can be used for the wireless networks and radio technologies mentioned above, as well as other wireless networks and radio technologies. For clarity, although various aspects may be described herein using terms commonly associated with 3G and / or 4G wireless technologies, various aspects of the present disclosure may be applied to communication systems based on other generations, such as 5G and later technologies (including NR technologies).

[0027] New Radio (NR) access (e.g., 5G technology) can support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidth (e.g., 80 MHz or above), millimeter wave (mmW) targeting high carrier frequency (e.g., 25 GHz or above), massive machine type communication MTC (mMTC) targeting non-backward compatible MTC technology, and / or mission critical targeting ultra-reliable low latency communication (URLLC). These services may include latency and reliability requirements. These services may also have different transmission time intervals (TTIs) to meet corresponding quality of service (QoS) requirements. In addition, these services can coexist in the same subframe.

[0028] Example Wireless Communication System

[0029] Figure 1 An example wireless communication network 100 is shown in which aspects of the present disclosure may be performed. For example, a UE 120 in the wireless communication network 100 may include a UL subband precoding module configured to perform (or assist the UE 120 in performing) operations 1600 described below with reference to FIG. 16 . Similarly, a base station 120 (e.g., a gNB) may include a UL subband precoding module configured to perform (or assist the base station 120 in performing) operations 1700 described below with reference to FIG. 17 .

[0030] As in Figure 1As shown in FIG, wireless communication network 100 may include multiple base stations (BSs) 110 and other network entities. A BS may be a station that communicates with a user equipment (UE). Each BS 110 may provide communication coverage for a specific geographic area. In 3GPP, the term "cell" may refer to the coverage area of ​​a Node B (NB) and / or the NB subsystem serving that coverage area, depending on the context in which the term is used. In NR systems, the term "cell" and next-generation Node B (gNB or gNodeB), NR BS, 5G NB, access point (AP), or transmit / receive point (TRP) may be interchangeable. In some examples, a cell may not necessarily be stationary, and the geographic area of ​​a cell may move depending on the location of a mobile BS. In some examples, base stations may be interconnected with each other and / or with one or more other base stations or network nodes (not shown) in wireless communication network 100 via various types of backhaul interfaces, such as direct physical connections, wireless connections, virtual networks, or interfaces using any suitable transport network.

[0031] In general, 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, subcarrier, frequency channel, tone, subband, etc. Each frequency can support a single RAT in a given geographic area to avoid interference between wireless networks with different RATs. In some cases, NR or 5G RAT networks can be deployed.

[0032] 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 subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a residence) and may allow restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in a residence, etc.). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In Figure 1In the example shown in FIG, BSs 110a, 110b, and 110c may be macro BSs for macro cells 102a, 102b, and 102c, respectively. BS 110x may be a pico BS for pico cell 102x. BSs 110y and 110z may be femto BSs for femto cells 102y and 102z, respectively. A BS may support one or more (e.g., three) cells.

[0033] The wireless communication network 100 may also include a relay station. A relay station is a station that receives transmissions of data and / or other information from an upstream station (e.g., a BS or a UE) and sends transmissions of data and / or other information to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that relays transmissions for other UEs. Figure 1 In the example shown in , a relay station 110r may communicate with a BS 110a and a UE 120r to facilitate communication between the BS 110a and the UE 120r. A relay station may also be referred to as a relay BS, a relay, or the like.

[0034] The wireless communication network 100 may be a heterogeneous network including different types of BSs (e.g., macro BSs, pico BSs, femto BSs, relays, etc.). These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in the wireless communication network 100. For example, a macro BS may have a high transmit power level (e.g., 20 watts), while a pico BS, a femto BS, and a relay may have a lower transmit power level (e.g., 1 watt).

[0035] The wireless communication network 100 can support synchronous operation or asynchronous operation. For synchronous operation, the BSs can have similar frame timing, and transmissions from different BSs can be approximately aligned in time. For asynchronous operation, the BSs can have different frame timing, and transmissions from different BSs can be misaligned in time. The techniques described herein can be used for both synchronous and asynchronous operation.

[0036] The network controller 130 may be coupled to a group of BSs and provide coordination and control for these BSs. The network controller 130 may communicate with the BSs 110 via a backhaul. The BSs 110 may also communicate with each other (eg, directly or indirectly) via a wireless or wired backhaul.

[0037] UEs 120 (e.g., 120x, 120y, etc.) may be dispersed throughout the wireless communication network 100, and each UE may be stationary or mobile. A UE may also be referred to as a mobile station, a terminal, an access terminal, a subscriber unit, a station, customer premises equipment (CPE), a cellular phone, 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 smartbook, an ultrabook, an appliance, a medical device or apparatus, a biometric sensor / device, a wearable device (such as a smart watch, smart clothing, smart glasses, a smart wristband, smart jewelry (e.g., a smart ring, a smart bracelet, etc.)), an entertainment device (e.g., a music device, a video device, a satellite radio device, etc.), a component or sensor of a vehicle, a smart meter / sensor, industrial manufacturing equipment, a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium. Some UEs may be considered machine type communication (MTC) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., which can communicate with a BS, another device (e.g., a remote device), or some other entity. A wireless node may provide, for example, connectivity to a network (e.g., a wide area network such as the Internet or a cellular network) or to a network via a wired or wireless communication link. Some UEs may be considered Internet of Things (IoT) devices, which may be narrowband IoT (NB-IoT) devices.

[0038] Some wireless networks (e.g., LTE) utilize orthogonal frequency division multiplexing (OFDM) on the downlink and single carrier frequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM divide the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, bins, etc. Each subcarrier can be modulated with data. In general, modulation symbols are sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can depend on the system bandwidth. For example, the subcarrier spacing can be 15 kHz and the minimum resource allocation (referred to as a "resource block" (RB)) can be 12 subcarriers (or 180 kHz). Therefore, for system bandwidths of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), the nominal fast Fourier transform (FFT) size can be equal to 128, 256, 512, 1024, or 2048, respectively. The system bandwidth may also be partitioned into subbands. For example, a subband may cover 1.08 MHz (ie, 6 resource blocks), and there may be 1, 2, 4, 8, or 16 subbands for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, respectively.

[0039] Communication systems (such as NR) can utilize OFDM with a cyclic prefix (CP) on both the uplink and downlink, as well as support for half-duplex operation using time division duplex (TDD). Beamforming can be supported and the beam direction can be dynamically configured. MIMO transmission with precoding can also be supported. The MIMO configuration in the DL can support up to 8 transmit antennas, with multi-layer DL transmission of up to 8 streams and up to 4 streams per UE. Multi-layer transmission with up to 4 streams per UE can be supported. Aggregation of multiple cells can be supported with up to 8 serving cells.

[0040] In some examples, access to the air interface can be scheduled. A scheduling entity (e.g., BS) allocates resources for communication between some or all devices and apparatuses within its service area or cell. The scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communications, the subordinate entities utilize the resources allocated by the scheduling entity. The base station is not the only entity that can be used as a scheduling entity. In some examples, a UE may be used as a scheduling entity and may schedule resources for one or more subordinate entities (e.g., one or more other UEs), and other UEs may utilize the resources scheduled by the UE to perform wireless communications. In some examples, a UE may be used as a scheduling entity in a peer-to-peer (P2P) network and / or in a mesh network. In the mesh network example, in addition to communicating with the scheduling entity, UEs may also communicate directly with each other.

[0041] exist Figure 1 In FIG, a solid line with double arrows indicates desired transmissions between a UE and a serving BS, which is a BS designated to serve the UE on the downlink and / or uplink. A thin dashed line with double arrows indicates interfering transmissions between the UE and the BS.

[0042] Figure 2 A diagram illustrating an example of implementing a communication protocol stack in a RAN (e.g., such as RAN 100) in accordance with various aspects of the present disclosure is shown. The illustrated communication protocol stack 200 may be implemented by a device operating in a wireless communication system, such as a 5G NR system (e.g., wireless communication network 100). In various examples, the layers of the protocol stack 200 may be implemented as separate software modules, as part of a processor or ASIC, as part of a non-co-located device connected by a communication link, or various combinations thereof. For example, a co-located and non-co-located implementation may be used in the protocol stack of a network access device or UE. Figure 2 As shown, the system can support various services through one or more protocols. One or more protocol layers of the protocol stack 200 can be implemented by the AN and / or the UE.

[0043] like Figure 2 As shown, the protocol stack 200 is in AN (e.g., Figure 1 The AN may implement the RRC layer 205, PDCP layer 210, RLC layer 215, MAC layer 220, PHY layer 225, and RF layer 230. For example, the CU-CP may implement the RRC layer 205 and PDCP layer 210. The DU may implement the RLC layer 215 and MAC layer 220. The AU / RRU may implement the PHY layer 225 and RF layer 230. The PHY layer 225 may include a high PHY layer and a low PHY layer.

[0044] The UE may implement the entire protocol stack 200 (eg, the RRC layer 205 , the PDCP layer 210 , the RLC layer 215 , the MAC layer 220 , the PHY layer 225 , and the RF layer 230 ).

[0045] Figure 3 Example components of BS 110 and UE 120 are shown (eg Figure 1 16 ), which may be used to implement various aspects of the present disclosure. For example, antennas 352, processors 366, 358, 364, and / or controller / processor 380 of UE 120 may be configured to (or used to) perform operations 1600 of FIG. 16 , and / or antennas 334, processors 320, 330, 338, and / or controller / processor 340 of BS 110 may be configured to (or used to) perform operations 1700 described below with reference to FIG. 17 .

[0046] At BS 110, a transmit processor 320 may receive data from a data source 312 and control information from a controller / processor 340. The control information may be for a physical broadcast channel (PBCH), a physical control format indicator channel (PCFICH), a physical hybrid ARQ indicator channel (PHICH), a physical downlink control channel (PDCCH), a group common PDCCH (GC PDCCH), etc. Data may be for a physical downlink shared channel (PDSCH), etc. The processor 320 may process (e.g., encode and symbol map) the data and control information, respectively, to obtain data symbols and control symbols. The processor 320 may also generate reference symbols, such as for a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a cell-specific reference signal (CRS). A transmit (TX) multiple-input multiple-output (MIMO) processor 330 may perform spatial processing (e.g., precoding) on ​​the data symbols, control symbols, and / or reference symbols, if applicable, and may provide output symbol streams to modulators (MODs) 332a through 332t. Each modulator 332 may process a corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and frequency upconvert) the output sample stream to obtain a downlink signal. The downlink signals from modulators 332a through 332t may be transmitted via antennas 334a through 334t, respectively.

[0047] At UE 120, antennas 352a through 352r can receive downlink signals from base station 110 and can provide received signals to demodulators (DEMODs) 354a through 354r, respectively, in the transceiver. Each demodulator 354 can condition (e.g., filter, amplify, downconvert, and digitize) a corresponding received signal to obtain input samples. Each demodulator can further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 356 can obtain received symbols from all demodulators 354a through 354r, perform MIMO detection on the received symbols (if applicable), and provide detected symbols. A receive processor 358 can process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for UE 120 to a data sink 360, and provide decoded control information to a controller / processor 380.

[0048] In a MIMO system, a transmitter (e.g., BS 120) includes multiple transmit antennas 354a through 354r, and a receiver (e.g., UE 110) includes multiple receive antennas 352a through 352r. Thus, there are multiple signal paths 394 from the transmit antennas 354a through 354r to the receive antennas 352a through 352r. Each of the transmitter and receiver can be implemented, for example, within UE 110, BS 120, or any other suitable wireless communication device.

[0049] The use of this multi-antenna technology enables wireless communication systems to exploit the spatial domain to support spatial multiplexing, beamforming, and transmit diversity. Spatial multiplexing can be used to send different data streams (also called layers) simultaneously on the same time-frequency resources. Data streams can be sent to a single UE to increase the data rate, or to multiple UEs to increase the overall system capacity, the latter being called multi-user MIMO (MU-MIMO). This is achieved by spatially precoding each data stream (i.e., multiplying the data stream by different weights and phase shifts) and then sending each spatially precoded stream through multiple transmit antennas on the downlink. The spatially precoded data streams arrive at the UE with different spatial signatures, which enables each UE to recover one or more data streams intended for that UE. On the uplink, each UE sends a spatially precoded data stream, which enables the base station to identify the source of each spatially precoded data stream.

[0050] The number of data streams or layers corresponds to the rank of the transmission. Typically, the rank of a MIMO system is limited by the number of transmit or receive antennas, whichever is lower. In addition, the channel conditions at the UE and other considerations such as the available resources at the base station may also affect the transmission rank. For example, the rank (and therefore the number of transmission layers) assigned to a particular UE on the downlink can be determined based on a rank indicator (RI) sent from the UE to the base station. The RI can be determined based on the antenna configuration (e.g., the number of transmit and receive antennas) and the signal to interference and noise ratio (SINR) measured on each receive antenna. The RI can indicate, for example, the number of layers that can be supported under current channel conditions. The base station can use the RI along with resource information (e.g., available resources and the amount of data to be scheduled for the UE) to assign a transmission rank to the UE.

[0051] On the uplink, at the UE 120, a transmit processor 364 may receive and process data from a data source 362 (e.g., for a physical uplink shared channel (PUSCH)) and control information from a controller / processor 380 (e.g., for a physical uplink control channel (PUCCH)). The transmit processor 364 may also generate reference symbols for reference signals (e.g., for a sounding reference signal (SRS)). The symbols from the transmit processor 364 may be precoded by a TX MIMO processor 366 (if applicable), further processed by demodulators 354a through 354r in the transceiver (e.g., for SC-FDM, etc.), and transmitted to the base station 110. At the BS 110, the uplink signal from the UE 120 may be received by the antenna 334, processed by the modulator 332, detected by the MIMO detector 336 (if applicable), and further processed by the receive processor 338 to obtain decoded data and control information transmitted by the UE 120. The receive processor 338 may provide decoded data to a data sink 339 and decoded control information to a controller / processor 340 .

[0052] Controllers / processors 340 and 380 may direct the operation of BS 110 and UE 120, respectively. Processor 340 and / or other processors and modules at base station 110 may perform or direct the execution of processes for the techniques described herein. Memories 342 and 382 may store data and program codes for BS 110 and UE 120, respectively. Scheduler 344 may schedule UEs for data transmission on the downlink and / or uplink.

[0053] Figure 4 4 is a diagram showing an example of a frame format 400 for NR. The transmission timeline for each of the downlink and uplink can be divided into units of radio frames. Each radio frame can have a predetermined duration (e.g., 10 ms) and can be divided into 10 subframes with indices 0 to 9, each subframe being 1 ms. Each subframe can include a variable number of slots, depending on the subcarrier spacing. Each slot can include a variable number of symbol periods (e.g., 7 or 14 symbols), depending on the subcarrier spacing. An index can be assigned to the symbol periods in each slot. A microslot (which can be referred to as a subslot structure) refers to a transmission time interval with a duration less than a slot (e.g., 2, 3, or 4 symbols). Each symbol in a slot can indicate the link direction of data transmission (e.g., DL, UL, or flexible), and the link direction of each subframe can be dynamically switched. The link direction can be based on the slot format. Each slot can include DL / UL data and DL / UL control information.

[0054] In NR, a synchronization signal (SS) block is transmitted. The SS block includes PSS, SSS, and two-symbol PBCH. It can be sent at a fixed time slot position (e.g., Figure 4 SS blocks are sent in the physical downlink shared channel (symbols 0-3 shown in ). PSS and SSS can be used by UE for cell search and acquisition. PSS can provide half-frame timing, and SS can provide CP length and frame timing. PSS and SSS can provide cell identity. PBCH carries certain basic system information, such as downlink system bandwidth, timing information within the radio frame, SS burst set period, system frame number, etc. SS blocks can be organized into SS bursts to support beam scanning. Additional system information, such as remaining minimum system information (RMSI), system information block (SIB), other system information (OSI), can be sent on the physical downlink shared channel (PDSCH) in certain subframes. For mmW, SS blocks can be sent up to sixty-four times, for example, using up to sixty-four different beam directions. The transmission of up to sixty-four SS blocks is called an SS burst set. The SS blocks in an SS burst set are sent in the same frequency region, while the SS blocks in different SS burst sets may be sent at different frequency positions.

[0055] The UE may operate in various radio resource configurations, including configurations associated with using a dedicated set of resources to send pilots (e.g., a radio resource control (RRC) dedicated state, etc.), or configurations associated with using a common set of resources to send pilots (e.g., an RRC common state, etc.). When operating in the RRC dedicated state, the UE may select a dedicated set of resources for sending pilot signals to the network. When operating in the RRC common state, the UE may select a common set of resources for sending pilot signals to the network. In either case, the pilot signals sent by the UE may be received by one or more network access devices (e.g., an AN or DU or a portion thereof). Each receiving network access device may be configured to receive and measure the pilot signals sent on the common set of resources, and also receive and measure the pilot signals sent on the dedicated set of resources allocated to the UE (for which the network access device is a member of a set of network access devices that monitor the UE). A CU receiving measurement results of one or more of the network access devices, or receiving a pilot signal sent to it by a network access device, may use the measurement results to identify a serving cell for a UE, or initiate a change to a serving cell for one or more of these UEs.

[0056] Example default configuration of uplink (UL) transmission configuration indicator (TCI) states

[0057] Various aspects of the present disclosure provide mechanisms that can provide a default configuration for an uplink transmission configuration state (e.g., when no TCI state is configured when an uplink transmission is to be performed). By providing techniques for identifying a default configuration for uplink transmission when no TCI state is configured, various aspects of the present disclosure can allow assumptions to be made to facilitate uplink beam selection. Before performing an uplink transmission in a multi-beam environment, the UE does not need to wait for the gNodeB to indicate the configuration of the UL TCI state. Because the UE may not need to wait for the gNodeB to indicate the configuration of the UL TCI state before performing an uplink transmission, latency can be reduced by reducing signaling in communications between the UE and the gNodeB, and the UE can start uplink transmissions to the gNodeB more quickly.

[0058] In Release 16, signaling overhead reduction may allow the gNB to not configure the spatial relationship for the Physical Uplink Control Channel (PUCCH) or SRS. A rule-based determination may be used to identify a default spatial relationship, which will be used if no spatial relationship has been configured. Using rule-based determination to identify the default spatial relationship may allow for reduced latency in communications between the UE and the gNB, which may improve overall throughput.

[0059] Enhancements for multi-beam operation can target different operating frequencies, such as FR1 and FR2 bands. Some of these enhancements can facilitate more efficient beam management to support intra-cell and inter-cell mobility and / or a greater number of configured TCI states. For example, a common beam can be used for data and control transmission and / or reception for both downlink and uplink (e.g., for intra-band carrier aggregation). A unified TCI framework for downlink / uplink beam indication can be used. In addition, signaling mechanisms, such as more dynamic use of control signaling, can be used to improve latency and efficiency.

[0060] For UEs equipped with multiple panels, various mechanisms can be used to facilitate uplink beam selection. For example, UL beam indication can be based on a unified TCI framework, where TCI states are associated with both UL and DL beam indications. Simultaneous transmission can be enabled across multiple panels, and fast panel selection can be enabled.

[0061] Enhancements to support multiple transmit / receive pair (TRP) deployments may target both FR1 and FR2 frequency bands. These enhancements may use multiple TRPs and / or multi-panel transmission and reception to improve the reliability and robustness of various channels, such as the physical downlink control channel (PDCCH), physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH), etc. Various features may enable inter-cell multi-TRP operation, and some enhancements may allow simultaneous multi-TRP transmission with multi-panel reception.

[0062] The TCI state framework for downlink transmissions can be extended to uplink transmissions. Beam management typically includes TCI state-based quasi-colocation (QCL) definitions for the downlink and spatial relationship-based configurations for the uplink. The default beam for use can be identified in the context of uplink spatial relations for PUCCH and / or SRS and when a scheduling DCI is received within a scheduling threshold for a scheduled transmission on a physical downlink shared channel. Typically, default parameters to be used for SRS resources are defined; however, when no UL TCI state is indicated or configured for uplink transmissions, default uplink parameters (e.g., default beam and / or default PL RS) may not be defined.

[0063] When no uplink TCI state is indicated or configured for uplink transmission of a physical uplink control channel, a physical uplink shared channel, a sounding reference signal and / or a physical random access channel (PRACH), embodiments of the present disclosure may allow a default uplink beam and / or path loss (PL) reference signal (RS) to be determined according to a set of rules.

[0064] Figure 5 Example operations 500 are shown that may be performed by a user equipment (UE) to determine an uplink beam for use in an uplink transmission.

[0065] As shown, operations 500 begin at 502, where the UE determines, based on one or more rules, at least one of a default uplink beam or a default path loss reference signal (PL RS) to use for uplink transmission in the absence of a signaled uplink transmission configuration indicator (TCI) state for uplink transmission. In some aspects, the one or more rules are based on whether a control resource set (CORESET) is configured in the active DL BWP. If the CORESET is not configured in the active DL BWP, the rules may be based on whether certain TCI states are activated in the active DL BWP.

[0066] At 504, the UE sends an uplink transmission based on the determination.

[0067] Figure 6 Example operations 600 are illustrated that may be performed by a network entity to process received uplink transmissions based on the timing of the uplink transmissions.

[0068] Operations 600 begin at 602, where a network entity determines, based on one or more rules, at least one of a default uplink beam or a default path loss reference signal (PL RS) for uplink transmission by a user equipment (UE) in the absence of a signaled uplink transmission configuration indicator (TCI) state for uplink transmission.

[0069] At 604, the network entity processes the uplink transmission based on the determination.

[0070] In some embodiments, when a CORESET is configured in an active downlink (DL) bandwidth part (BWP), the default beam and / or corresponding PL RS may follow a spatial QCL reference signal, such as a QCL type reference signal identified in the downlink TCI state or QCL assumption of one of the CORESETs in the active DL BWP. The QCL assumption may, for example, be a QCL assumption for receiving the CORESETs in the active DL BWP. For example, the QCL assumption may be based on the CORESET with the lowest identifier or the highest identifier in the active DL BWP. In some aspects, the default uplink beam may correspond to the downlink beam indicated by the DL TCI state.

[0071] In some embodiments, when a CORESET for uplink transmission is not configured in the active DL BWP, but at least one PDSCH TCI state is activated in the active DL BWP, the default UL beam and / or the corresponding default PL RS may follow the QCL type D reference signal in the active PDSCH TCI state or other downlink TCI states in the active DL BWP. The determined UL beam and / or PL RS may correspond to, for example, the beam and / or PL RS associated with the lowest or highest TCI state identifier in the active DL BWP. That is, in addition to or instead of using CSI-RS or SSB as a QCL source from which a QCL assumption may be made, the PDSCH TCI state may be used as a quasi-co-located (QCL) source.

[0072] In some embodiments, if an uplink transmission is scheduled within a scheduling threshold using a DCI carrying a corresponding UL TCI state, the default TCI state may be used for uplink transmission for a time period corresponding to the scheduling threshold period. The scheduling threshold period may be a configured value or determined based on the capabilities of the UE. After the scheduling threshold period has elapsed, uplink transmission may be performed based on the parameters included in the UL TCI state (e.g., beam indication, PL RS, etc.). However, before the scheduling threshold period expires, the default TCI state may be used for uplink transmission. The default TCI state may be different from the UL TCI state carried in the received DCI.

[0073] Figure 7 A communication device 700 is shown that may include devices configured to perform operations for the techniques disclosed herein (such as Figure 5 7. The communication device 700 includes various components (e.g., corresponding to means plus functional components) for the operations shown. The communication device 700 includes a processing system 702 coupled to a transceiver 708 (e.g., a transmitter and / or a receiver). The transceiver 708 is configured to transmit and receive signals for the communication device 700, such as the various signals described herein, via an antenna 710. The processing system 702 can be configured to perform processing functions for the communication device 700, including processing signals received and / or to be transmitted by the communication device 700.

[0074] The processing system 702 includes a processor 704 coupled to a computer-readable medium / memory 712 via a bus 706. In some aspects, the computer-readable medium / memory 712 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 704, cause the processor 704 to perform Figure 5The operations shown or other operations for performing the various techniques for beam switching gaps discussed herein. In certain aspects, in accordance with aspects of the present disclosure, the computer-readable medium / memory 712 stores: code 714 for determining, based on one or more rules, at least one of a default uplink beam or a default path loss reference signal (PL RS) to be used for uplink transmission in the absence of a signaled uplink transmission configuration indicator (TCI) state for uplink transmission; and code 716 for transmitting an uplink transmission based on the determination. In certain aspects, the processor 704 has circuitry configured to implement the code stored in the computer-readable medium / memory 712. In accordance with aspects of the present disclosure, the processor 704 includes circuitry 718 for determining, based on one or more rules, at least one of a default uplink beam or a default path loss reference signal (PL RS) to be used for uplink transmission in the absence of a signaled uplink transmission configuration indicator (TCI) state for uplink transmission; and circuitry 720 for transmitting an uplink transmission based on the determination.

[0075] Figure 8 A communication device 800 is shown that may include devices configured to perform operations for the techniques disclosed herein (such as Figure 6 800 includes various components (e.g., corresponding to means plus functional components) for the operations shown. The communication device 800 includes a processing system 802 coupled to a transceiver 808 (e.g., a transmitter and / or a receiver). The transceiver 808 is configured to transmit and receive signals for the communication device 800, such as the various signals described herein, via an antenna 810. The processing system 802 can be configured to perform processing functions for the communication device 800, including processing signals received and / or to be transmitted by the communication device 800.

[0076] The processing system 802 includes a processor 804 coupled to a computer-readable medium / memory 812 via a bus 806. In certain aspects, the computer-readable medium / memory 812 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 804, cause the processor 804 to perform Figure 6The operations shown or other operations for performing the various techniques for beam switching gaps discussed herein. In certain aspects, according to aspects of the present disclosure, the computer-readable medium / memory 812 stores: code 814 for determining, based on one or more rules, at least one of a default uplink beam or a default path loss reference signal (PL RS) for a user equipment (UE) to use for receiving an uplink transmission in the absence of a signaled uplink transmission configuration indicator (TCI) state for the uplink transmission; and code 816 for processing the uplink transmission based on the determination. In certain aspects, the processor 804 has circuitry configured to implement the code stored in the computer-readable medium / memory 812. According to aspects of the present disclosure, processor 804 includes circuitry 818 for determining, based on one or more rules, at least one of a default uplink beam or a default path loss reference signal (PL RS) for a user equipment (UE) to use for receiving an uplink transmission in the absence of a signaled uplink transmission configuration indicator (TCI) state for the uplink transmission, and circuitry 820 for processing the uplink transmission based on the determination.

[0077] Example Embodiments

[0078] Embodiment 1: A method for wireless communication by a user equipment (UE), comprising: in the absence of a signaled uplink transmission configuration indicator (TCI) state for uplink transmission, determining at least one of a default uplink beam or a default path loss reference signal (PL RS) to be used for the uplink transmission based on one or more rules; and sending the uplink transmission according to the determination.

[0079] Embodiment 2: The method according to embodiment 1, wherein the uplink transmission includes at least one of a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), a sounding reference signal (SRS) or a physical random access channel (PRACH).

[0080] Embodiment 3: A method according to embodiment 1 or 2, wherein, according to one of the rules, the UE uses a downlink transmission configuration indicator (TCI) state as a quasi-co-located source to determine at least one of the default uplink beam or PLRS.

[0081] Embodiment 4: The method according to embodiment 3, wherein the UE determines an uplink beam corresponding to the downlink beam indicated by the downlink TCI state as the default uplink beam.

[0082] Embodiment 5: A method according to embodiment 1 or 2, wherein, according to one of the rules: the UE determines at least one of the default uplink beam or the default PL RS based on a spatial quasi-co-located (QCL) reference signal (RS) or QCL assumption of at least one control resource set (CORESET) in an active downlink bandwidth part (BWP).

[0083] Embodiment 6: The method according to embodiment 5, wherein according to one of the rules: the spatial QCL RS includes a QCL type D RS.

[0084] Embodiment 7: The method of embodiment 5 or 6, wherein the at least one CORESET is selected based on a value of its CORESET ID relative to one or more other CORESET IDs in the active downlink BWP.

[0085] Embodiment 8: A method according to embodiment 1 or 2, wherein, according to one of the rules: when a control resource set (CORESET) is not configured in an active downlink bandwidth part (BWP), the UE determines at least one of the default uplink beam or the default PL RS based on a spatial quasi-co-located (QCL) reference signal (RS) in an active physical downlink shared channel (PDSCH) transmission configuration indicator (TCI) state in the active downlink bandwidth part (BWP).

[0086] Embodiment 9: The method of embodiment 8, wherein the active PDSCH TCI state is selected based on a value of its TCI state ID relative to one or more other TCI state IDs in the active downlink BWP.

[0087] Embodiment 10: A method according to embodiments 1 to 9, wherein, if the uplink transmission is scheduled within a threshold scheduling period through downlink control information (DCI), the UE is configured to use the default uplink beam or default PL RS, and the DCI carries a corresponding uplink transmission configuration indicator (TCI) state for the uplink transmission.

[0088] Embodiment 11: The method according to embodiment 10, wherein the threshold scheduling period is at least one of a configured value or determined based on the capability of the UE.

[0089] Embodiment 12: A method for wireless communication by a network entity, comprising: in the absence of a signaled uplink transmission configuration indicator (TCI) state for uplink transmission, determining at least one of a default uplink beam or a default path loss reference signal (PL RS) for a user equipment (UE) to use for receiving the uplink transmission based on one or more rules; and processing the uplink transmission according to the determination.

[0090] Embodiment 13: The method according to embodiment 12, wherein the uplink transmission includes at least one of a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), a sounding reference signal (SRS) or a physical random access channel (PRACH).

[0091] Embodiment 14: A method according to embodiment 12 or 13, wherein, according to one of the rules, the network entity determines that the UE uses a downlink transmission configuration indicator (TCI) state as a quasi-co-located source to determine at least one of the default uplink beam or PL RS.

[0092] Embodiment 15: The method according to embodiment 14, wherein the network entity determines that the UE will use the uplink beam corresponding to the downlink beam indicated by the downlink TCI state as the default uplink beam.

[0093] Embodiment 16: A method according to embodiment 12 or 13, wherein, according to one of the rules: the network entity determines that the UE uses at least one of the default uplink beam or the default PL RS based on a spatial quasi-co-located (QCL) reference signal (RS) or QCL assumption of at least one control resource set (CORESET) in an active downlink bandwidth part (BWP).

[0094] Embodiment 17: The method according to embodiment 16, wherein according to one of the rules: the spatial QCL RS includes a QCL type D RS.

[0095] Embodiment 18: The method of embodiment 16 or 17, wherein the at least one CORESET is selected based on a value of its CORESET ID relative to one or more other CORESET IDs in the active downlink BWP.

[0096] Embodiment 19: A method according to embodiment 12 or 13, wherein, according to one of the rules: when a control resource set (CORESET) is not configured in an active downlink bandwidth part (BWP), the network entity determines that the UE uses at least one of the default uplink beam or the default PL RS based on a spatial quasi-co-located (QCL) reference signal (RS) in an active physical downlink shared channel (PDSCH) transmission configuration indicator (TCI) state in the active downlink bandwidth part (BWP).

[0097] Embodiment 20: The method of embodiment 19, wherein the active PDSCH TCI state is selected based on a value of its TCI state ID relative to one or more other TCI state IDs in the active downlink BWP.

[0098] Embodiment 21: A method according to embodiments 12 to 20, wherein, if the uplink transmission is scheduled within a threshold scheduling period through downlink control information (DCI), the network entity determines that the UE is configured to use the default uplink beam or default PL RS, and the DCI carries a corresponding uplink transmission configuration indicator (TCI) state for the uplink transmission.

[0099] Embodiment 22: The method according to embodiment 21, wherein the threshold scheduling period is at least one of a configured value or determined based on the capability of the UE.

[0100] Embodiment 23: An apparatus for wireless communication by a user equipment (UE), comprising: a processor; and a memory having instructions, which, when executed by the processor, perform the operations according to any one of embodiments 1 to 11.

[0101] Embodiment 24: An apparatus for wireless communication by a network entity, comprising: a processor; and a memory having instructions, the instructions, when executed by the processor, performing the operations according to any one of embodiments 12 to 22.

[0102] Embodiment 25: An apparatus for wireless communication by a user equipment (UE), comprising: a unit capable of performing the operations according to any one of embodiments 1 to 11.

[0103] Embodiment 26: An apparatus for wireless communication by a network entity, comprising: a unit capable of performing the operations according to any one of embodiments 12 to 22.

[0104] Embodiment 27: A computer readable medium having instructions stored thereon, the instructions, when executed by a processor, performing the operations of any one of embodiments 1 to 11.

[0105] Embodiment 28: A computer readable medium having instructions stored thereon that, when executed by a processor, perform the operations of any one of Embodiments 12 to 22.

[0106] Additional considerations

[0107] The methods disclosed herein include one or more steps or actions for implementing the methods. These method steps and / or actions may be interchangeable with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0108] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including single members. For example, "at least one of a, b, or c" is intended to encompass any combination of a, b, c, ab, ac, bc, and abc, as well as multiples of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c).

[0109] As used herein, the term "determining" includes a wide variety of actions. For example, "determining" may include calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, database, or another data structure), ascertaining, and the like. Furthermore, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. Furthermore, "determining" may include resolving, selecting, choosing, establishing, and the like.

[0110] The foregoing description is provided to enable any person skilled in the art to implement the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the overall principles defined herein may be applied to other aspects. Accordingly, the claims are not intended to be limited to the aspects shown herein, but are to be given the full scope consistent with the text of the claims, wherein, unless otherwise specifically stated, reference to an element in the singular is not intended to mean "one and only one," but rather "one or more." Unless otherwise explicitly stated, the term "some" refers to one or more. All structural and functional equivalents of the elements throughout the various aspects described in this disclosure are expressly incorporated herein by reference and are intended to be encompassed by the claims, such structural and functional equivalents being known or becoming known to those skilled in the art. Furthermore, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be interpreted under 35 U.S.C. § 112, paragraph 6, unless the element is explicitly recited using the phrase "means for..." or, in the case of a method claim, the element is recited using the phrase "step for..."

[0111] The various operations of the methods described above may be performed by any appropriate units capable of performing the corresponding functions. These units may include various hardware and / or software components and / or modules, including but not limited to: circuits, application specific integrated circuits (ASICs) or processors. For example, Figure 3 The various processors shown may be configured to perform operations 1000 and 1100 of Figures 10 and 11 .

[0112] The various illustrative logic blocks, modules, and circuits described in conjunction with the present disclosure may be implemented or performed using a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0113] If implemented in hardware, an example hardware configuration may include a processing system in a wireless node. The processing system may be implemented using a bus architecture. Depending on the specific application and overall design constraints of the processing system, the bus may include any number of interconnecting buses and bridges. The bus may connect various circuits including a processor, a machine-readable medium, and a bus interface. In addition, the bus interface may also be used to connect a network adapter to the processing system via the bus. The network adapter may be used to implement the signal processing functions of the PHY layer. In the user terminal 120 (see Figure 1 ), a user interface (e.g., a keypad, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also connect various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, etc., which are well known in the art and therefore will not be described further. The processor may be implemented using one or more general and / or special purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits that can execute software. Those skilled in the art will recognize how to best implement the functionality described for the processing system based on the specific application and the overall design constraints imposed on the entire system.

[0114] If implemented in software, the functionality may be stored on or transmitted via a computer-readable medium as one or more instructions or codes. Whether referred to as software, firmware, middleware, microcode, hardware description language, or other terms, software should be broadly interpreted to mean instructions, data, or any combination thereof. Computer-readable media includes both computer storage media and communication media, including any medium that facilitates the transfer of computer programs from one location to another. The processor may be responsible for managing the bus and general processing, including executing software modules stored on a machine-readable storage medium. The computer-readable storage medium may be coupled to the processor so that the processor can read information from and write information to the storage medium. Alternatively, the storage medium may be an integral part of the processor. For example, the machine-readable medium may include a transmission line, a carrier modulated by data, and / or a computer-readable storage medium with instructions stored thereon, separate from the wireless node, all of which may be accessed by the processor via a bus interface. Alternatively, or in addition, the machine-readable medium or any portion thereof may be integrated into the processor, for example, in the form of a cache and / or a general register file. For example, examples of machine-readable storage media may include RAM (random access memory), flash memory, ROM (read-only memory), PROM (programmable read-only memory), EPROM (erasable programmable read-only memory), EEPROM (electrically erasable programmable read-only memory), registers, magnetic disks, optical disks, hard drives, or any other suitable storage media, or any combination thereof. The machine-readable medium may be embodied in a computer program product.

[0115] A software module may include a single instruction or many instructions and may be distributed across several different code segments, distributed among different programs, and distributed across multiple storage media. A computer-readable medium may include multiple software modules. A software module includes instructions that, when executed by a device such as a processor, cause a processing system to perform various functions. A software module may include a sending module and a receiving module. Each software module may be located in a single storage device or distributed across multiple storage devices. For example, when a triggering event occurs, a software module may be loaded from a hard drive into RAM. During execution of the software module, the processor may load some of the instructions into a cache to increase access speed. Subsequently, one or more cache lines may be loaded into a general register file for execution by the processor. It will be understood that when a function of a software module is mentioned below, such function is implemented by the processor when executing instructions from the software module.

[0116] Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies (e.g., infrared (IR), radio, and microwave), then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies (e.g., infrared, radio, and microwave) are included in the definition of medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and optical disc. Optical disks, where magnetic disks typically reproduce data magnetically, and optical disks reproduce data optically using lasers. Thus, in some aspects, computer-readable media may include non-transitory computer-readable media (e.g., tangible media). Furthermore, for other aspects, computer-readable media may include transitory computer-readable media (e.g., signals). Combinations of the above should also be included within the scope of computer-readable media.

[0117] Thus, certain aspects may include a computer program product for performing the operations presented herein. For example, such a computer program product may include a computer-readable medium having instructions stored (and / or encoded) thereon, the instructions being executable by one or more processors to perform the operations described herein (e.g., instructions for performing the operations described herein and illustrated in Figures 15 and 16).

[0118] In addition, it should be understood that the modules and / or other appropriate units for performing the methods and techniques described herein can be downloaded and / or otherwise obtained by the user terminal and / or base station where applicable. For example, such a device can be coupled to a server to facilitate the transmission of units for performing the methods described herein. Alternatively, the various methods described herein can be provided via a storage unit (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or a floppy disk, etc.) so that the user terminal and / or base station can obtain the various methods when the storage unit is coupled to or provided to the device. In addition, any other appropriate technology for providing the methods and techniques described herein to a device can be used.

[0119] It should be understood that the claims are not limited to the precise configuration and components shown above. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

1. A method for wireless communication by a user equipment (UE), comprising: determining, in absence of a signaled uplink transmission configuration indicator (TCI) state for an uplink transmission, at least one of a default uplink beam or a default path loss reference signal (PL RS) to use for the uplink transmission based on one or more rules; as well as sending the uplink transmission based on the determination, In which, if the uplink transmission is scheduled within a threshold scheduling period through downlink control information (DCI), the UE is configured to use the default uplink beam or default PL RS, and the DCI carries the corresponding uplink transmission configuration indicator (TCI) state for the uplink transmission.

2. The method according to claim 1, wherein The uplink transmission includes at least one of a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), a sounding reference signal (SRS), or a physical random access channel (PRACH).

3. The method according to claim 1, wherein According to one of the rules, the UE uses a downlink transmission configuration indicator (TCI) state as a quasi-co-located source to determine at least one of the default uplink beam or the PL RS.

4. The method according to claim 3, wherein: The UE determines the uplink beam corresponding to the downlink beam indicated by the downlink TCI state as the default uplink beam.

5. The method according to claim 1, wherein According to one of the rules: The UE determines at least one of the default uplink beam or the default PL RS based on a spatial quasi-co-located (QCL) reference signal (RS) or a QCL assumption of at least one control resource set (CORESET) in an active downlink bandwidth part (BWP).

6. The method according to claim 5, wherein: According to one of the rules: The spatial QCL RS includes a QCL type D RS.

7. The method according to claim 5, wherein: The at least one CORESET is selected based on a value of its CORESET ID relative to one or more other CORESET IDs in the active downlink BWP.

8. The method according to claim 1, wherein According to one of the rules: When a control resource set (CORESET) is not configured in an active downlink bandwidth part (BWP), the UE determines at least one of the default uplink beam or the default PL RS based on a spatial quasi-colocated (QCL) reference signal (RS) in an active physical downlink shared channel (PDSCH) transmission configuration indicator (TCI) state in the active downlink bandwidth part (BWP).

9. The method according to claim 8, wherein The active PDSCH TCI state is selected based on the value of its TCI state ID relative to one or more other TCI state IDs in the active downlink BWP.

10. The method according to claim 1, wherein The threshold scheduling period is at least one of a configured value or determined based on a capability of the UE.

11. A method for wireless communication by a network entity, comprising: determining, in the absence of a signaled uplink transmission configuration indicator (TCI) state for an uplink transmission, at least one of a default uplink beam or a default path loss reference signal (PL RS) for a user equipment (UE) to use for receiving the uplink transmission based on one or more rules; as well as processing the uplink transmission based on the determination, Wherein, if the uplink transmission is scheduled within a threshold scheduling period through downlink control information (DCI), the network entity determines that the UE is configured to use the default uplink beam or default PL RS, and the DCI carries the corresponding uplink transmission configuration indicator (TCI) state for the uplink transmission.

12. The method according to claim 11, wherein The uplink transmission includes at least one of a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), a sounding reference signal (SRS), or a physical random access channel (PRACH).

13. The method according to claim 11, wherein According to one of the rules, the network entity determines that the UE uses a downlink transmission configuration indicator (TCI) state as a quasi-co-located source to determine at least one of the default uplink beam or the PL RS.

14. The method according to claim 13, wherein The network entity determines that the UE will use the uplink beam corresponding to the downlink beam indicated by the downlink TCI state as the default uplink beam.

15. The method according to claim 11, wherein According to one of the rules: The network entity determines that the UE uses at least one of the default uplink beam or the default PL RS based on a spatial quasi-co-located (QCL) reference signal (RS) or a QCL assumption of at least one control resource set (CORESET) in an active downlink bandwidth part (BWP).

16. The method according to claim 15, wherein According to one of the rules: The spatial QCL RS includes a QCL type D RS.

17. The method according to claim 15, wherein: The at least one CORESET is selected based on a value of its CORESET ID relative to one or more other CORESET IDs in the active downlink BWP.

18. The method according to claim 11, wherein According to one of the rules: When a control resource set (CORESET) is not configured in an active downlink bandwidth part (BWP), the network entity determines that the UE uses at least one of the default uplink beam or the default PL RS based on a spatial quasi-colocated (QCL) reference signal (RS) in an active physical downlink shared channel (PDSCH) transmission configuration indicator (TCI) state in the active downlink bandwidth part (BWP).

19. The method according to claim 18, wherein The active PDSCH TCI state is selected based on the value of its TCI state ID relative to one or more other TCI state IDs in the active downlink BWP.

20. The method according to claim 11, wherein The threshold scheduling period is at least one of a configured value or determined based on a capability of the UE.

21. An apparatus for wireless communication by a user equipment (UE), comprising: A processor configured to: determining, in absence of a signaled uplink transmission configuration indicator (TCI) state for an uplink transmission, at least one of a default uplink beam or a default path loss reference signal (PL RS) to use for the uplink transmission based on one or more rules; and sending the uplink transmission based on the determination, wherein, if the uplink transmission is scheduled within a threshold scheduling period via downlink control information (DCI), the UE is configured to use the default uplink beam or default PL RS, and the DCI carries a corresponding uplink transmission configuration indicator (TCI) state for the uplink transmission; as well as Memory.

22. The device according to claim 21, wherein According to one of the rules: The UE determines at least one of the default uplink beam or the default PL RS based on a spatial quasi-co-located (QCL) reference signal (RS) or a QCL assumption of at least one control resource set (CORESET) in an active downlink bandwidth part (BWP).

23. The device according to claim 22, wherein According to one of the rules: The spatial QCL RS includes a QCL type D RS.

24. The apparatus according to claim 22, wherein The at least one CORESET is selected based on a value of its CORESET ID relative to one or more other CORESET IDs in the active downlink BWP.

25. The apparatus according to claim 21, wherein According to one of the rules: When a control resource set (CORESET) is not configured in an active downlink bandwidth part (BWP), the UE determines at least one of the default uplink beam or the default PL RS based on a spatial quasi-colocated (QCL) reference signal (RS) in an active physical downlink shared channel (PDSCH) transmission configuration indicator (TCI) state in the active downlink bandwidth part (BWP).

26. The device according to claim 25, wherein The active PDSCH TCI state is selected based on the value of its TCI state ID relative to one or more other TCI state IDs in the active downlink BWP.

27. An apparatus for wireless communication by a user equipment (UE), comprising: means for determining, in absence of a signaled uplink transmission configuration indicator (TCI) state for an uplink transmission, at least one of a default uplink beam or a default path loss reference signal (PL RS) to use for the uplink transmission based on one or more rules; as well as means for sending the uplink transmission based on the determination, In which, if the uplink transmission is scheduled within a threshold scheduling period through downlink control information (DCI), the UE is configured to use the default uplink beam or default PL RS, and the DCI carries the corresponding uplink transmission configuration indicator (TCI) state for the uplink transmission.

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