WO2021155572A1

WO2021155572A1 - Default spatial relation for srs resource transmission

Info

Publication number: WO2021155572A1
Application number: PCT/CN2020/074505
Authority: WO
Inventors: Bingchao LIU; Chenxi Zhu; Wei Ling; Lingling Xiao; Yi Zhang
Original assignee: Lenovo (Beijing) Limited
Priority date: 2020-02-07
Filing date: 2020-02-07
Publication date: 2021-08-12

Abstract

Methods and apparatuses for determining default spatial relation are disclosed. A method comprises determining a default spatial relation for SRS resource transmission according to a higher layer parameter CORESETPoolIndex; and transmitting the SRS resource using the determined default spatial relation.

Description

DEFAULT SPATIAL RELATION FOR SRS RESOURCE TRANSMISSION

FIELD

The subject matter disclosed herein generally relates to wireless communications, and more particularly relates to methods and apparatuses for determining default spatial relation for SRS transmission in multi-TRP scenario.

BACKGROUND

The following abbreviations are herewith defined, at least some of which are referred to within the following description: Third Generation Partnership Project (3GPP) , European Telecommunications Standards Institute (ETSI) , Frequency Division Duplex (FDD) , Frequency Division Multiple Access (FDMA) , Long Term Evolution (LTE) , New Radio (NR) , Very Large Scale Integration (VLSI) , Random Access Memory (RAM) , Read-Only Memory (ROM) , Erasable Programmable Read-Only Memory (EPROM or Flash Memory) , Compact Disc Read-Only Memory (CD-ROM) , Local Area Network (LAN) , Wide Area Network (WAN) , Personal Digital Assistant (PDA) , User Equipment (UE) , Uplink (UL) , Evolved Node B (eNB) , Next Generation Node B (gNB) , Downlink (DL) , Central Processing Unit (CPU) , Graphics Processing Unit (GPU) , Field Programmable Gate Array (FPGA) , Dynamic RAM (DRAM) , Synchronous Dynamic RAM (SDRAM) , Static RAM (SRAM) , Liquid Crystal Display (LCD) , Light Emitting Diode (LED) , Organic LED (OLED) , Orthogonal Frequency Division Multiplexing (OFDM) , Radio Resource Control (RRC) , Time-Division Duplex (TDD) , Time Division Multiplex (TDM) , User Entity/Equipment (Mobile Terminal) (UE) , Uplink (UL) , Universal Mobile Telecommunications System (UMTS) , Physical Downlink Shared Channel (PDSCH) , Physical Uplink Shared Channel (PUSCH) , Physical Uplink Control Channel (PUCCH) , Downlink control information (DCI) , single DCI (S-DCI) , transmission reception point (TRP) , multiple TRP (multi-TRP or M-TRP) , frequency range 2 (FR2) , Quasi Co-Location (QCL) , channel state information reference signal (CSI-RS) , CSI-RS Resource Indicator (CRI) , Code Division Multiplexing (CDM) , Transmission Configuration Indication (TCI) , Sounding Reference Signal (SRS) , Control Resource Set (CORESET) , Synchronization Signal (SS) , reference signal (RS) , component carrier (CC) , carrier aggregation (CA) , master information block (MIB) , band width part (BWP) , physical broadcast channel (PBCH) .

Multi-DCI based multi-TRP is an important scenario in Release 16, the default DL reception beam determination for the UE has been supported in NR Release 16 based on the configured higher layer parameter CORESETPoolIndex for each CORESET in multi-TRP scenario.

This disclosure targets the determination of the default spatial relation for the SRS (including aperiodic SRS, semi-persistent SRS or periodic SRS) resource transmission.

BRIEF SUMMARY

Methods and apparatuses for determining default spatial relation are disclosed.

In one embodiment, a method comprises determining a default spatial relation for SRS resource transmission according to a higher layer parameter CORESETPoolIndex; and transmitting the SRS resource using the determined default spatial relation.

In one embodiment, the SRS resource is for aperiodic SRS scheduled by DCI. When CORESET (s) are configured on a scheduled CC; and the higher layer parameter CORESETPoolIndex is configured for each CORESET, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among CORESET (s) in the active DL-BWP in the scheduled CC with the same value of CORESETPoolIndex as that configured for the CORESET transmitting the triggering DCI on a scheduling CC. When CORESET (s) are configured on a scheduled CC; and the higher layer parameter CORESETPoolIndex is not configured for at least one of CORESET (s) on the scheduled CC and the CORESET transmitting the triggering DCI on a scheduling CC, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all the configured CORESET (s) in the active DL-BWP in the scheduled CC. When no CORESET is configured on a scheduled CC; and at least one TCI state is activated for PDSCH transmission on the scheduled CC, the default spatial relation for SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the scheduled CC. When no CORESET is configured on a scheduled CC; no TCI state is activated on the scheduled CC; and no simultaneousTCI-CellList is configured for the UE or one or more simultaneousTCI-CellList are configured for the UE but the scheduled CC does not belong to any simultaneousTCI-CellList, the default spatial relation for SRS resource transmission is determined by the RS resource obtained from the SS/PBCH block reception that the UE uses to obtain MIB. When no CORESET is configured on a scheduled CC; no TCI state is activated on the scheduled CC; the scheduled CC belongs to a simultaneousTCI-CellList configured for the UE; and at least one CORESET is configured for at least one CC belonging to the simultaneousTCI-CellList, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all CORESET (s) configured in the active DL-BWP in the scheduled CC with the lowest CC index among all CCs configured with CORESET within the simultaneousTCI-CellList. When no CORESET is configured on a scheduled CC; no TCI state is activated on the scheduled CC; the scheduled CC belongs to a simultaneousTCI-CellList configured for the UE; no CORESET is configured for all CCs within the simultaneousTCI-CellList; and at least one CC in the simultaneousTCI-CellList is configured with at least one TCI state for PDSCH, the default spatial relation for SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the CC with the lowest CC index among all CCs with activated TCI state for PDSCH within the simultaneousTCI-CellList.

In another embodiment, for the semi-persistent (SP) SRS activated by a SP SRS Activation/Deactivation MAC CE, when a higher layer parameter enableDefaultBeamPlForSRS is set as ‘enable’ , the SP SRS is associated with a CORESETPoolIndex by a field in the SP SRS Activation/Deactivation MAC CE or by the CORESET transmitting the DCI scheduling the PDSCH carrying the SP SRS Activation/Deactivation MAC CE, or a CORESETPoolIndex is directly configured in the SRS resource or SRS resource set containing the SRS resource.

In some embodiment, for the periodic SRS, when a higher layer parameter enableDefaultBeamPlForSRS is set as ’ enable’ , each periodic SRS resource or each periodic SRS resource set is associated with a CORESETPoolIndex.

In some embodiment, when CORESET (s) are configured on a CC transmitting the SP or periodic SRS resource, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest ID among all the CORESETs configured with the same CORESETPoolIndex as that associated with the SP or periodic SRS resource. When no CORESET is configured on a CC transmitting the SP or periodic SRS resource; and at least one TCI state is activated for PDSCH in the active DL-BWP in the CC, the default spatial relation for SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the CC. When no CORESET is configured on a CC transmitting the SP or periodic SRS resource; and no TCI state is activated for PDSCH in the active DL-BWP in the CC, the default spatial relation for SRS resource transmission is determined by the RS resource obtained from the SS/PBCH block reception that the UE uses to obtain MIB on the CC.

In one embodiment, a method comprises determining a default spatial relation for SRS resource transmission according to a higher layer parameter CORESETPoolIndex; and receiving the SRS resource using the determined default spatial relation.

In another embodiment, a remote unit comprises a processor configured to determine a default spatial relation for SRS resource transmission according to a higher layer parameter CORESETPoolIndex; and a transmitter configured to transmit the SRS resource using the determined default spatial relation.

In yet another embodiment, a base unit comprises a processor configured to determine a default spatial relation for SRS resource transmission according to a higher layer parameter CORESETPoolIndex; and a receiver configured to receive the SRS resource using the determined default spatial relation.

BRIEF DESCRIPTION OF THE DRAWINGS

A more particular description of the embodiments briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only some embodiments, and are not therefore to be considered to be limiting of scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

Figure 1 illustrates an example of cross-carrier SRS scheduling;

Figure 2 illustrates a semi-persistent SRS Activation/Deactivation MAC CE;

Figure 3 is a schematic flow chart diagram illustrating an embodiment of a method;

Figure 4 is a schematic flow chart diagram illustrating a further embodiment of a method; and

Figure 5 is a schematic block diagram illustrating apparatuses according to one embodiment.

DETAILED DESCRIPTION

As will be appreciated by one skilled in the art that certain aspects of the embodiments may be embodied as a system, apparatus, method, or program product. Accordingly, embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc. ) or an embodiment combining software and hardware aspects that may generally all be referred to herein as a “circuit” , “module” or “system” . Furthermore, embodiments may take the form of a program product embodied in one or more computer readable storage devices storing machine-readable code, computer readable code, and/or program code, referred to hereafter as “code” . The storage devices may be tangible, non-transitory, and/or non-transmission. The storage devices may not embody signals. In a certain embodiment, the storage devices only employ signals for accessing code.

Certain functional units described in this specification may be labeled as “modules” , in order to more particularly emphasize their independent implementation. For example, a module may be implemented as a hardware circuit comprising custom very-large-scale integration (VLSI) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.

Modules may also be implemented in code and/or software for execution by various types of processors. An identified module of code may, for instance, include one or more physical or logical blocks of executable code which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but, may include disparate instructions stored in different locations which, when joined logically together, include the module and achieve the stated purpose for the module.

Indeed, a module of code may contain a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules and may be embodied in any suitable form and organized within any suitable type of data structure. This operational data may be collected as a single data set, or may be distributed over different locations including over different computer readable storage devices. Where a module or portions of a module are implemented in software, the software portions are stored on one or more computer readable storage devices.

Any combination of one or more computer readable medium may be utilized. The computer readable medium may be a computer readable storage medium. The computer readable storage medium may be a storage device storing code. The storage device may be, for example, but need not necessarily be, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

A non-exhaustive list of more specific examples of the storage device would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, random access memory (RAM) , read-only memory (ROM) , erasable programmable read-only memory (EPROM or Flash Memory) , portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.

Code for carrying out operations for embodiments may include any number of lines and may be written in any combination of one or more programming languages including an object-oriented programming language such as Python, Ruby, Java, Smalltalk, C++, or the like, and conventional procedural programming languages, such as the "C" programming language, or the like, and/or machine languages such as assembly languages. The code may be executed entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the very last scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN) , or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider) .

Reference throughout this specification to “one embodiment” , “an embodiment” , or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment” , “in an embodiment” , and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including” , “comprising” , “having” , and variations thereof mean “including but are not limited to” , unless otherwise expressly specified. An enumerated listing of items does not imply that any or all of the items are mutually exclusive, otherwise unless expressly specified. The terms “a” , “an” , and “the” also refer to “one or more” unless otherwise expressly specified.

Furthermore, described features, structures, or characteristics of various embodiments may be combined in any suitable manner. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that embodiments may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid any obscuring of aspects of an embodiment.

Aspects of different embodiments are described below with reference to schematic flowchart diagrams and/or schematic block diagrams of methods, apparatuses, systems, and program products according to embodiments. It will be understood that each block of the schematic flowchart diagrams and/or schematic block diagrams, and combinations of blocks in the schematic flowchart diagrams and/or schematic block diagrams, can be implemented by code. This code may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which are executed via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the schematic flowchart diagrams and/or schematic block diagrams for the block or blocks.

The code may also be stored in a storage device that can direct a computer, other programmable data processing apparatus, or other devices, to function in a particular manner, such that the instructions stored in the storage device produce an article of manufacture including instructions which implement the function specified in the schematic flowchart diagrams and/or schematic block diagrams block or blocks.

The code may also be loaded onto a computer, other programmable data processing apparatus, or other devices, to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the code executed on the computer or other programmable apparatus provides processes for implementing the functions specified in the flowchart and/or block diagram block or blocks.

The schematic flowchart diagrams and/or schematic block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of apparatuses, systems, methods and program products according to various embodiments. In this regard, each block in the schematic flowchart diagrams and/or schematic block diagrams may represent a module, segment, or portion of code, which includes one or more executable instructions of the code for implementing the specified logical function (s) .

It should also be noted that in some alternative implementations, the functions noted in the block may occur out of the order noted in the Figures. For example, two blocks shown in succession may substantially be executed concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more blocks, or portions thereof, to the illustrated Figures.

Although various arrow types and line types may be employed in the flowchart and/or block diagrams, they are understood not to limit the scope of the corresponding embodiments. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the depicted embodiment. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted embodiment. It will also be noted that each block of the block diagrams and/or flowchart diagrams, and combinations of blocks in the block diagrams and/or flowchart diagrams, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and code.

The description of elements in each Figure may refer to elements of proceeding figures. Like numbers refer to like elements in all figures, including alternate embodiments of like elements.

In all of the below embodiments, the spatial relation information (e.g. spatial domain transmission filter) is not configured to the UE (or although configured, no activation command is received at the UE) for transmission of SRS resource (s) .

SRS can be aperiodic SRS, semi-persistent SRS or periodic SRS.

The first embodiment is related to aperiodic SRS.

Aperiodic SRS used for codebook, non-codebook, beam management and antenna switching can be triggered by DCI format 0_1 or format 1_1 with a non-zero ‘SRS request’ field. Cross-carrier aperiodic SRS triggering in carrier aggregation (CA) scenario can be supported by DCI format 0_1 and format 1_1. DCI format 2_3 with SRS request can be used to trigger an aperiodic SRS resource transmission on another carrier of serving cells in a condition that a UE is not configured for PUSCH and/or PUCCH transmission. At least when no pathloss reference RSs for power control are configured for the SRS resource set by RRC signalling, the default spatial relation for aperiodic SRS resource transmission in a component carrier (CC) in frequency range 2 (FR2) triggered by DCI format 0_1 or 1_1 or 2_3 can be determined according to different configurations for scheduling CC and scheduled CC. The DCI used for triggering SRS resource is transmitted in the scheduling CC. The triggered SRS resource is transmitted in the scheduled CC. The configurations may include but are not limited to: in-carrier scheduling or cross-carrier scheduling; whether CORESET (s) are configured on the scheduled CC and/or the scheduling CC; whether CORESET (s) are configured with higher layer parameter CORESETPoolIndex; whether TCI state is activated for the PDSCH transmission on the scheduled CC; whether simultaneousTCI-CellList is configured, etc.

Scenario 1: in-carrier scheduling. In-carrier scheduling means that the scheduling CC and the scheduled CC are the same CC.

Case 1: when (1) CORESET (s) are configured on the scheduled CC for the SRS resource transmission; and

(2) the higher layer parameter CORESETPoolIndex is configured for each CORESET,

the default spatial relation for the SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among CORESET (s) in the active DL-BWP in the scheduled CC configured with the same value of CORESETPoolIndex as that configured for the CORESET transmitting the scheduling DCI.

This means that the UE will transmit the SRS resource with the same spatial domain transmission filter as that used for the reception of the CORESET with the lowest CORESET-ID in the active DL-BWP in the scheduled CC configured with the same value of CORESETPoolIndex as that configured for the CORESET transmitting the scheduling DCI.

Scenario 2: cross-carrier scheduling and the scheduled CC configured with CORESET. Cross-carrier scheduling means that the scheduling CC and the scheduled CC are different CCs. In scenario 2, CORESET (s) are configured on the scheduled CC.

Case 2-1: when (1) CORESET (s) are configured on the scheduled CC for the SRS resource transmission; and

(2) the higher layer parameter CORESETPoolIndex is not configured for any CORESET on the scheduled CC,

the default spatial relation for the SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all the CORESET (s) configured in the active DL-BWP in the scheduled CC no matter whether the CORESET transmitting the DCI is configured with a CORESETPoolIndex or not.

This means that the UE will transmit the SRS resource with the same spatial domain transmission filter as that used for the reception of the CORESET with the lowest CORESET-ID in the active DL-BWP in the scheduled CC.

Case 2_2: when (1) CORESET (s) are configured on the scheduled CC for the SRS resource transmission;

(2) each configured CORESET on the scheduled CC is configured with a higher layer parameter CORESETPoolIndex; and

(3) the CORESET transmitting the DCI on the scheduling CC is also configured with a CORESETPoolIndex,

the default spatial relation for the SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among CORESET (s) configured with the same value of CORESETPoolIndex in the active DL-BWP in the scheduled CC as that configured for the CORESET transmitting the scheduling DCI on the scheduling CC.

This means that the UE will transmit the SRS resource with the same spatial domain transmission filter as that used for the reception of the CORESET with the lowest CORESET-ID in the active DL-BWP in the scheduled CC configured with the same value of CORESETPoolIndex as that configured for the CORESET transmitting the scheduling DCI on the scheduling CC.

Case 2_3: when (1) CORESET (s) are configured on the scheduled CC for the SRS resource transmission;

(3) the CORESET transmitting the DCI on the scheduling CC is not configured with a CORESETPoolIndex,

the default spatial relation for the SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all the CORESET (s) configured in the active DL-BWP in the scheduled CC.

For case 2_3, the default spatial relation for transmission of a SRS resource with SRS source ID N may be alternatively determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all the CORESETs in the active DL-BWP in the scheduled CC with configured CORESETPoolIndex = MOD(N, 2) . For example, the default spatial relation of

SRS resources

0, 2, 4, …is determined by the lowest CORESET with CORESETPoolIndex = 0 (in particular, the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all the CORESETs in the active DL-BWP in the scheduled CC with configured CORESETPoolIndex = 0) , and the default spatial relation of SRS resources 1, 3, 5, … is determined by the lowest CORESET with CORESETPoolIndex = 1 (in particular, the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all the CORESETs in the active DL-BWP in the scheduled CC with configured CORESETPoolIndex = 1) .

Another alternative determination of the default spatial relation for the SRS resource transmission for case 2_3 is as follows: two slotOffset, e.g. slotOffset0 and slotOffset1, are configured for the SRS resource set with resourceType = ‘aperiodic’ . The default spatial relation of SRS resource (s) in the slot determined by slotOffset0 is determined by CORESETPoolIndex = 0 (in particular, the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all the CORESETs in the active DL-BWP in the scheduled CC with configured CORESETPoolIndex = 0) ; and the default spatial relation of SRS resource (s) in the slot determined by slotOffset1 is determined by CORESETPoolIndex = 1 (in particular, the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all the CORESETs in the active DL-BWP in the scheduled CC with configured CORESETPoolIndex = 1) .

Figure 1 illustrates an example of cross-carrier SRS scheduling for e.g. cases 2_1, 2_2 and 2_3.

As illustrated in Figure 1, UE receives a DCI format 0_1 or 1_1 or 2_3 with a non-zero ‘SRS request’ field in slot n on CC#1 (scheduling CC) scheduling an aperiodic SRS resource transmission on CC#2 (scheduled CC) in slot n+k.

If all the CORESETs configured on both CC#1 and CC#2 are configured with a higher layer parameter CORESETPoolIndex and the DCI is transmitted from a CORESET configured with CORESETPoolIndex = 0 (an example of case 2_2) , the default spatial relation for the corresponding SRS resource transmission on CC#2 is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among CORESET (s) in the active DL-BWP in the scheduled CC configured with CORESETPoolIndex = 0 on CC#2.

If either the CORESET transmitting the DCI on CC#1 or the CORESETs configured on CC#2 is not configured with the higher layer parameter CORESETPoolIndex (an example of case 2_1 or case 2_3) , the default spatial relation for the corresponding SRS resource transmission on CC#2 is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all the CORESETs configured in the active DL-BWP in CC#2.

Scenario 3: cross-carrier scheduling and no CORESET configured on the scheduled CC. In scenario 3, no CORESET is configured on the scheduled CC.

Case 3_1: when (1) no CORESET is configured on the scheduled CC; and

(2) at least one TCI state is activated for the PDSCH transmission on the scheduled CC,

the default spatial relation for the SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the scheduled CC no matter whether the CORESET transmitting the DCI on the scheduling CC is configured with a CORESETPoolIndex or not.

Take Figure 1 as an example, if both CC#1 and CC#2 are configured for single-DCI based single-TRP transmission mode, the default spatial relation for the SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in CC#2.

Case 3_2: when (1) no CORESET is configured on the scheduled CC;

(2) no TCI state is activated for the PDSCH transmission on the scheduled CC; and

(3) no simultaneousTCI-CellList is configured for the UE, or one or more simultaneousTCI-CellList are configured for the UE but the scheduled CC does not belong to any simultaneousTCI-CellList,

if the UE receives MIB in the scheduled CC, the default spatial relation for the SRS resource transmission is determined by the RS resource obtained from the SS/PBCH block reception that the UE uses to obtain MIB.

This means that the UE will transmit the SRS resource with the same spatial domain transmission filter as that used for the reception of the RS resource obtained from the SS/PBCH block reception that the UE uses to obtain MIB.

If the UE does not receive MIB on the scheduled CC, the default spatial relation for the SRS resource transmission can be determined on the basis of the scheduling CC according to Case 1. That is, the default spatial relation for the SRS resource transmission on the scheduled CC is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among CORESET (s) configured in the active DL-BWP in the scheduling CC.

Note that all CCs listed in a same simultaneousTCI-CellList share the same TCI state value for PDSCH and/or PDCCH transmission. The gNB can only configure the TCI state for PDSCH and/or PDCCH for one CC in the simultaneousTCI-CellList.

Case 3_3: when (1) no CORESET is configured on the scheduled CC;

(3) one or more simultaneousTCI-CellList are configured for the UE and the scheduled CC belongs to a simultaneousTCI-CellList,

In case that at least one CORESET is configured for at least one CC belonging to the simultaneousTCI-CellList, the default spatial relation for the SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all CORESET (s) configured in the active DL-BWP in the CC with the lowest CC index among all CCs configured with CORESET within the simultaneousTCI-CellList no matter whether the CORESET transmitting the DCI on the scheduling CC is configured with a CORESETPoolIndex or not.

For example, CC#2 (the scheduled CC) , CC#3, CC#4 and CC#5 belong to a simultaneousTCI-CellList. No CORESET is configured on the CC#2 (the scheduled CC) . No TCI state is activated for the PDSCH transmission on the CC#2 (the scheduled CC) . CORESETs are configured on the CC#4 and CC#5 but not on CC#3. The default spatial relation for SRS resource transmission on CC#2 is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all the CORESET (s) configured in the active DL-BWP in CC#4 (which has the lowest CC index among CCs that are configured with CORESET within the simultaneousTCI-CellList) .

In case that no CORESET is configured for all the CCs belonging to the simultaneousTCI-CellList, but at least one CC in the one simultaneousTCI-CellList is configured with at least one TCI state for PDSCH, the default spatial relation for the SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the CC with the lowest CC index among all CCs with activated TCI state for PDSCH within the simultaneousTCI-CellList no matter whether the CORESET transmitting the DCI on the scheduling CC is configured with a CORESETPoolIndex or not.

For example, CC#2 (the scheduled CC) , CC#3, CC#4 and CC#5 belong to a simultaneousTCI-CellList. No CORESET is configured on the CC#2 (the scheduled CC) . No TCI state is activated for the PDSCH transmission on the CC#2 (the scheduled CC) . CORESETs are not configured on the CC#3, CC#4 and CC#5, either. Each of CC#4 and CC#5 (but not CC#3) is activated with at least one TCI state for PDSCH for the active DL-BWP. The default spatial relation for the SRS resource transmission on CC#2 is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the CC#4 (which has the lowest CC index among the CCs with activated TCI state for PDSCH within the simultaneousTCI-CellList) .

The second embodiment is related to semi-persistent (SP) SRS.

SP SRS resource is activated or deactivated by a SP SRS Activation/Deactivation MAC CE. The spatial relation for each activated SP SRS resource may be configured in the MAC CE. On the other hand, if the UE support the default spatial relation feature for SRS, i.e. the UE is configured with a higher layer parameter enableDefaultBeamPlForSRS with the value of enable, the spatial relation for each SP SRS resource may not be configured in the MAC CE. Instead, the UE can transmit the SP SRS resource by using a default spatial relation.

For the multi-TRP scenario, TRP-specific SP SRS should be supported at least for multi-DCI based multi-TRP scenario. If the UE is configured with enableDefaultBeamPlForSRS = ’enable’ in multi-DCI based multi-TRP scenario, the spatial relation for each SRS resource may not be configured in the MAC CE. In order to support TRP-specific SP SRS activation or deactivation and transmission, the SP SRS resource can be activated per TRP, i.e. per CORESETPoolIndex.

The association between a SP SRS resource and CORESETPoolIndex may be achieved by introducing an additional CORESETPoolIndex field in the current SP SRS Activation/Deactivation MAC CE as illustrated in Figure 2. As illustrated in Figure 2, the MAC CE is associated with a CORESETPoolIndex indicated by the T field. Therefore, the activated SP SRS resource is also associated with the indicated CORESETPoolIndex. The T field (CORESETPoolIndex field) is only present if CORESETPoolIndex is configured for the CORESET configured on the BWP in the CC indicated by the MAC CE.

The association between the SP SRS resource and CORESETPoolIndex may be alternatively achieved by being based on the DCI scheduling the PDSCH carrying the MAC CE. The activated SP SRS resource is associated with the CORESETPoolIndex configured for the CORESET transmitting the DCI scheduling the PDSCH carrying the MAC CE.

Alternatively, the associated CORESETPoolIndex is directly configured in the SRS resource or the SRS resource set containing the SRS resource.

The default spatial relation for SP SRS resource transmission in a CC (e.g. in FR2) can be determined by the following manner:

Case 4_1: when (1) CORESET (s) are configured on the CC,

the default spatial relation for SP SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest ID among all the CORESETs configured with the same CORESETPoolIndex as that associated with the activated SRS resource.

This means that the UE will transmit the SP SRS resource with the same spatial domain transmission filter as that used for the reception of the CORESET with the lowest ID among all the CORESETs configured with the same CORESETPoolIndex as that associated with the activated SRS resource.

Case 4_2: when (1) no CORESET is configured on the CC; and

(2) at least one TCI state is activated for PDSCH in the active DL-BWP in the CC,

the default spatial relation for SP SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the CC.

Case 4_3: when (1) no CORESET is configured on the CC; and

(2) no TCI state is activated for PDSCH in the active DL-BWP in the CC,

the default spatial relation for SP SRS resource transmission is determined by the RS resource obtained from the SS/PBCH block reception that the UE uses to obtain MIB on this CC if applicable.

This means that the UE will transmit the SP SRS resource with the same spatial domain transmission filter as that used for the reception of the RS resource obtained from the SS/PBCH block reception that the UE uses to obtain MIB.

The third embodiment is related to periodic SRS.

For the periodic SRS without configured spatialRelationInfo where the UE is configured with enableDefaultBeamPlForSRS = ‘enable’ , each SRS resource set with resourceType = periodic can be associated with a CORESETPoolIndex when each CORESET configured on the CC for the UE is configured with a CORESETPoolIndex to support TRP-specific periodic SRS resource transmission with default spatial relation in multi-DCI based multi-TRP transmission by using the follows configuration. As each SRS resource set is associated with a CORESETPoolIndex, each SRS resource contained in the SRS resource set is associated with the CORESETPoolIndex. Alternatively, each SRS resource is associated with the CORESETPoolIndex.

SRS-Config information element

The default spatial relation for periodic SRS resource transmission in a CC (e.g. in FR2) can be determined by the following manner:

Case 5_1: when (1) CORESET (s) are configured on the CC,

the default spatial relation for periodic SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest ID among all the CORESETs configured with the same CORESETPoolIndex as that associated with the periodic SRS.

This means that the UE will transmit the periodic SRS resource with the same spatial domain transmission filter as that used for the reception of the CORESET with the lowest ID among all the CORESETs configured with the same CORESETPoolIndex as that associated with the periodic SRS.

Case 5_2: when (1) no CORESET is configured on the CC, and

the default spatial relation for periodic SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the CC.

Case 5_3: when (1) no CORESET is configured on the CC, and

(2) no TCI state is activated for PDSCH in the active DL-BWP in the CC,

the default spatial relation for periodic SRS resource transmission is determined by the RS resource obtained from the SS/PBCH block reception that the UE uses to obtain MIB if applicable.

This means that the UE will transmit the periodic SRS resource with the same spatial domain transmission filter as that used for the reception of the RS resource obtained from the SS/PBCH block reception that the UE uses to obtain MIB.

Figure 3 is a schematic flow chart diagram illustrating an embodiment of a method 300 according to the present application. In some embodiments, the method 300 is performed by an apparatus, such as a base unit. In certain embodiments, the method 300 may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

The method 300 may include 302 determining a default spatial relation for SRS resource transmission according to a higher layer parameter CORESETPoolIndex; and 304 receiving the SRS resource using the determined default spatial relation.

Figure 4 is a schematic flow chart diagram illustrating a further embodiment of a method 400 according to the present application. In some embodiments, the method 400 is performed by an apparatus, such as a remote unit. In certain embodiments, the method 400 may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

The method 400 may include 402 determining a default spatial relation for SRS resource transmission according to a higher layer parameter CORESETPoolIndex; and 404 transmitting the SRS resource using the determined default spatial relation.

Referring to Figure 5, the UE (i.e. the remote unit) includes a processor, a memory, and a transceiver. The processor implements a function, a process, and/or a method which are proposed in Figure 4. The eNB (i.e. base unit) includes a processor, a memory, and a transceiver. The processors implement a function, a process, and/or a method which are proposed in Figure 3. Layers of a radio interface protocol may be implemented by the processors. The memories are connected with the processors to store various pieces of information for driving the processors. The transceivers are connected with the processors to transmit and/or receive a radio signal. Needless to say, the transceiver may be implemented as a transmitter to transmit the radio signal and a receiver to receive the radio signal.

The memories may be positioned inside or outside the processors and connected with the processors by various well-known means.

In the embodiments described above, the components and the features of the embodiments are combined in a predetermined form. Each component or feature should be considered as an option unless otherwise expressly stated. Each component or feature may be implemented not to be associated with other components or features. Further, the embodiment may be configured by associating some components and/or features. The order of the operations described in the embodiments may be changed. Some components or features of any embodiment may be included in another embodiment or replaced with the component and the feature corresponding to another embodiment. It is apparent that the claims that are not expressly cited in the claims are combined to form an embodiment or be included in a new claim.

The embodiments may be implemented by hardware, firmware, software, or combinations thereof. In the case of implementation by hardware, according to hardware implementation, the exemplary embodiment described herein may be implemented by using one or more application-specific integrated circuits (ASICs) , digital signal processors (DSPs) , digital signal processing devices (DSPDs) , programmable logic devices (PLDs) , field programmable gate arrays (FPGAs) , processors, controllers, micro-controllers, microprocessors, and the like.

Embodiments may be practiced in other specific forms. The described embodiments are to be considered in all respects to be only illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

A method comprising:

determining a default spatial relation for SRS resource transmission according to a higher layer parameter CORESETPoolIndex; and

transmitting the SRS resource using the determined default spatial relation.
The method of claim 1, wherein, for aperiodic SRS scheduled by DCI, when CORESET (s) are configured on a scheduled CC; and the higher layer parameter CORESETPoolIndex is configured for each CORESET, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among CORESET (s) in the active DL-BWP in the scheduled CC with the same value of CORESETPoolIndex as that configured for the CORESET transmitting the triggering DCI on a scheduling CC.
The method of claim 1, wherein for aperiodic SRS scheduled by DCI, when CORESET (s) are configured on a scheduled CC; and the higher layer parameter CORESETPoolIndex is not configured for at least one of CORESET (s) on the scheduled CC and the CORESET transmitting the triggering DCI on a scheduling CC, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all the configured CORESET (s) in the active DL-BWP in the scheduled CC.
The method of claim 1, wherein for the aperiodic SRS scheduled by DCI, when no CORESET is configured on a scheduled CC; and at least one TCI state is activated for PDSCH transmission on the scheduled CC, the default spatial relation for SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the scheduled CC.
The method of claim 1, wherein for the aperiodic SRS scheduled by DCI, when no CORESET is configured on a scheduled CC; no TCI state is activated on the scheduled CC; and no simultaneousTCI-CellList is configured for the UE or one or more simultaneousTCI-CellList are configured for the UE but the scheduled CC does not belong to any simultaneousTCI-CellList, the default spatial relation for SRS resource transmission is determined by the RS resource obtained from the SS/PBCH block reception that the UE uses to obtain MIB.
The method of claim 1, wherein for the aperiodic SRS scheduled by DCI, when no CORESET is configured on a scheduled CC; no TCI state is activated on the scheduled CC; the scheduled CC belongs to a simultaneousTCI-CellList configured for the UE; and at least one CORESET is configured for at least one CC belonging to the simultaneousTCI-CellList, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all CORESET (s) configured in the active DL-BWP in the CC with the lowest CC index among all CCs configured with CORESET within the simultaneousTCI-CellList.
The method of claim 1, wherein for the aperiodic SRS scheduled by DCI, when no CORESET is configured on a scheduled CC; no TCI state is activated on the scheduled CC; the scheduled CC belongs to a simultaneousTCI-CellList configured for the UE; no CORESET is configured for all CCs within the simultaneousTCI-CellList; and at least one CC in the simultaneousTCI-CellList is configured with at least one TCI state for PDSCH, the default spatial relation for SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the CC with the lowest CC index among all CCs with activated TCI state for PDSCH within the simultaneousTCI-CellList.
The method of claim 1, wherein for the semi-persistent (SP) SRS activated by a SP SRS Activation/Deactivation MAC CE, when a higher layer parameter enableDefaultBeamPlForSRS is set as ‘enable’ , the SP SRS is associated with a CORESETPoolIndex by a field in the SP SRS Activation/Deactivation MAC CE or by the CORESET transmitting the DCI scheduling the PDSCH carrying the SP SRS Activation/Deactivation MAC CE, or a CORESETPoolIndex is directly configured in the SRS resource or SRS resource set containing the SRS resource.
The method of claim 1, wherein for the periodic SRS, when a higher layer parameter enableDefaultBeamPlForSRS is set as ’ enable’ , each periodic SRS resource or each periodic SRS resource set is associated with a CORESETPoolIndex.
The method of claim 8 or 9, wherein, when CORESET (s) are configured on a CC transmitting the SP or periodic SRS resource, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest ID among all the CORESETs configured with the same CORESETPoolIndex as that associated with the SP or periodic SRS resource.
The method of claim 8 or 9, wherein, when no CORESET is configured on a CC transmitting the SP or periodic SRS resource; and at least one TCI state is activated for PDSCH in the active DL-BWP in the CC, the default spatial relation for SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the CC.
The method of claim 8 or 9, wherein, when no CORESET is configured on a CC transmitting the SP or periodic SRS resource; and no TCI state is activated for PDSCH in the active DL-BWP in the CC, the default spatial relation for SRS resource transmission is determined by the RS resource obtained from the SS/PBCH block reception that the UE uses to obtain MIB on the CC.
A method comprising:

determining a default spatial relation for SRS resource transmission according to a higher layer parameter CORESETPoolIndex; and

receiving the SRS resource using the determined default spatial relation.
The method of claim 13, wherein, for aperiodic SRS scheduled by DCI, when CORESET (s) are configured on a scheduled CC; and the higher layer parameter CORESETPoolIndex is configured for each CORESET, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among CORESET (s) in the active DL-BWP in the scheduled CC with the same value of CORESETPoolIndex as that configured for the CORESET transmitting the triggering DCI on a scheduling CC.
The method of claim 13, wherein for aperiodic SRS scheduled by DCI, when CORESET (s) are configured on a scheduled CC; and the higher layer parameter CORESETPoolIndex is not configured for at least one of CORESET (s) on the scheduled CC and the CORESET transmitting the triggering DCI on a scheduling CC, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all the configured CORESET (s) in the active DL-BWP in the scheduled CC.
The method of claim 13, wherein for the aperiodic SRS scheduled by DCI, when no CORESET is configured on a scheduled CC; and at least one TCI state is activated for PDSCH transmission on the scheduled CC, the default spatial relation for SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the scheduled CC.
The method of claim 13, wherein for the aperiodic SRS scheduled by DCI, when no CORESET is configured on a scheduled CC; no TCI state is activated on the scheduled CC; and no simultaneousTCI-CellList is configured for the UE or one or more simultaneousTCI-CellList are configured for the UE but the scheduled CC does not belong to any simultaneousTCI-CellList, the default spatial relation for SRS resource transmission is determined by the RS resource obtained from the SS/PBCH block reception that the UE uses to obtain MIB.
The method of claim 13, wherein for the aperiodic SRS scheduled by DCI, when no CORESET is configured on a scheduled CC; no TCI state is activated on the scheduled CC; the scheduled CC belongs to a simultaneousTCI-CellList configured for the UE; and at least one CORESET is configured for at least one CC belonging to the simultaneousTCI-CellList, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all CORESET (s) configured in the active DL-BWP in the CC with the lowest CC index among all CCs configured with CORESET within the simultaneousTCI-CellList.
The method of claim 13, wherein for the aperiodic SRS scheduled by DCI, when no CORESET is configured on a scheduled CC; no TCI state is activated on the scheduled CC; the scheduled CC belongs to a simultaneousTCI-CellList configured for the UE; no CORESET is configured for all CCs within the simultaneousTCI-CellList; and at least one CC in the simultaneousTCI-CellList is configured with at least one TCI state for PDSCH, the default spatial relation for SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the CC with the lowest CC index among all CCs with activated TCI state for PDSCH within the simultaneousTCI-CellList.
The method of claim 13, wherein for the semi-persistent (SP) SRS activated by a SP SRS Activation/Deactivation MAC CE, when a higher layer parameter enableDefaultBeamPlForSRS is set as ‘enable’ , the SP SRS is associated with a CORESETPoolIndex by a field in the SP SRS Activation/Deactivation MAC CE or by the CORESET transmitting the DCI scheduling the PDSCH carrying the SP SRS Activation/Deactivation MAC CE, or a CORESETPoolIndex is directly configured in the SRS resource or SRS resource set containing the SRS resource.
The method of claim 13, wherein for the periodic SRS, when a higher layer parameter enableDefaultBeamPlForSRS is set as ’ enable’ , each periodic SRS resource or each periodic SRS resource set is associated with a CORESETPoolIndex.
The method of claim 20 or 21, wherein, when CORESET (s) are configured on a CC transmitting the SP or periodic SRS resource, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest ID among all the CORESETs configured with the same CORESETPoolIndex as that associated with the SP or periodic SRS resource.
The method of claim 20 or 21, wherein, when no CORESET is configured on a CC transmitting the SP or periodic SRS resource; and at least one TCI state is activated for PDSCH in the active DL-BWP in the CC, the default spatial relation for SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the CC.
The method of claim 20 or 21, wherein, when no CORESET is configured on a CC transmitting the SP or periodic SRS resource; and no TCI state is activated for PDSCH in the active DL-BWP in the CC, the default spatial relation for SRS resource transmission is determined by the RS resource obtained from the SS/PBCH block reception that the UE uses to obtain MIB on the CC.
A remote unit, comprising:

a processor configured to determine a default spatial relation for SRS resource transmission according to a higher layer parameter CORESETPoolIndex; and

a transmitter configured to transmit the SRS resource using the determined default spatial relation.
The remote unit of claim 25, wherein, for aperiodic SRS scheduled by DCI, when CORESET (s) are configured on a scheduled CC; and the higher layer parameter CORESETPoolIndex is configured for each CORESET, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among CORESET (s) in the active DL-BWP in the scheduled CC with the same value of CORESETPoolIndex as that configured for the CORESET transmitting the triggering DCI on a scheduling CC.
The remote unit of claim 25, wherein for aperiodic SRS scheduled by DCI, when CORESET (s) are configured on a scheduled CC; and the higher layer parameter CORESETPoolIndex is not configured for at least one of CORESET (s) on the scheduled CC and the CORESET transmitting the triggering DCI on a scheduling CC, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all the configured CORESET (s) in the active DL-BWP in the scheduled CC.
The remote unit of claim 25, wherein for the aperiodic SRS scheduled by DCI, when no CORESET is configured on a scheduled CC; and at least one TCI state is activated for PDSCH transmission on the scheduled CC, the default spatial relation for SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the scheduled CC.
The remote unit of claim 25, wherein for the aperiodic SRS scheduled by DCI, when no CORESET is configured on a scheduled CC; no TCI state is activated on the scheduled CC; and no simultaneousTCI-CellList is configured for the remote unit or one or more simultaneousTCI-CellList are configured for the remote unit but the scheduled CC does not belong to any simultaneousTCI-CellList, the default spatial relation for SRS resource transmission is determined by the RS resource obtained from the SS/PBCH block reception that the remote unit uses to obtain MIB.
The remote unit of claim 25, wherein for the aperiodic SRS scheduled by DCI, when no CORESET is configured on a scheduled CC; no TCI state is activated on the scheduled CC; the scheduled CC belongs to a simultaneousTCI-CellList configured for the remote unit; and at least one CORESET is configured for at least one CC belonging to the simultaneousTCI-CellList, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all CORESET (s) configured in the active DL-BWP in the CC with the lowest CC index among all CCs configured with CORESET within the simultaneousTCI-CellList.
The remote unit of claim 25, wherein for the aperiodic SRS scheduled by DCI, when no CORESET is configured on a scheduled CC; no TCI state is activated on the scheduled CC; the scheduled CC belongs to a simultaneousTCI-CellList configured for the remote unit; no CORESET is configured for all CCs within the simultaneousTCI-CellList; and at least one CC in the simultaneousTCI-CellList is configured with at least one TCI state for PDSCH, the default spatial relation for SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the CC with the lowest CC index among all CCs with activated TCI state for PDSCH within the simultaneousTCI-CellList.
The remote unit of claim 25, wherein for the semi-persistent (SP) SRS activated by a SP SRS Activation/Deactivation MAC CE, when a higher layer parameter enableDefaultBeamPlForSRS is set as ‘enable’ , the SP SRS is associated with a CORESETPoolIndex by a field in the SP SRS Activation/Deactivation MAC CE or by the CORESET transmitting the DCI scheduling the PDSCH carrying the SP SRS Activation/Deactivation MAC CE, or a CORESETPoolIndex is directly configured in the SRS resource or SRS resource set containing the SRS resource.
The remote unit of claim 25, wherein for the periodic SRS, when a higher layer parameter enableDefaultBeamPlForSRS is set as ’ enable’ , each periodic SRS resource or each periodic SRS resource set is associated with a CORESETPoolIndex.
The remote unit of claim 32 or 33, wherein, when CORESET (s) are configured on a CC transmitting the SP or periodic SRS resource, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest ID among all the CORESETs configured with the same CORESETPoolIndex as that associated with the SP or periodic SRS resource.
The remote unit of claim 32 or 33, wherein, when no CORESET is configured on a CC transmitting the SP or periodic SRS resource; and at least one TCI state is activated for PDSCH in the active DL-BWP in the CC, the default spatial relation for SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the CC.
The remote unit of claim 32 or 33, wherein, when no CORESET is configured on a CC transmitting the SP or periodic SRS resource; and no TCI state is activated for PDSCH in the active DL-BWP in the CC, the default spatial relation for SRS resource transmission is determined by the RS resource obtained from the SS/PBCH block reception that the remote unit uses to obtain MIB on the CC.
A base unit, comprising:

a processor configured to determine a default spatial relation for SRS resource transmission according to a higher layer parameter CORESETPoolIndex; and

a receiver configured to receive the SRS resource using the determined default spatial relation.
The base unit of claim 37, wherein, for aperiodic SRS scheduled by DCI, when CORESET (s) are configured on a scheduled CC; and the higher layer parameter CORESETPoolIndex is configured for each CORESET, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among CORESET (s) in the active DL-BWP in the scheduled CC with the same value of CORESETPoolIndex as that configured for the CORESET transmitting the triggering DCI on a scheduling CC.
The base unit of claim 37, wherein for aperiodic SRS scheduled by DCI, when CORESET (s) are configured on a scheduled CC; and the higher layer parameter CORESETPoolIndex is not configured for at least one of CORESET (s) on the scheduled CC and the CORESET transmitting the triggering DCI on a scheduling CC, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type- D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all the configured CORESET (s) in the active DL-BWP in the scheduled CC.
The base unit of claim 37, wherein for the aperiodic SRS scheduled by DCI, when no CORESET is configured on a scheduled CC; and at least one TCI state is activated for PDSCH transmission on the scheduled CC, the default spatial relation for SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the scheduled CC.
The base unit of claim 37, wherein for the aperiodic SRS scheduled by DCI, when no CORESET is configured on a scheduled CC; no TCI state is activated on the scheduled CC; and no simultaneousTCI-CellList is configured for the UE or one or more simultaneousTCI-CellList are configured for the UE but the scheduled CC does not belong to any simultaneousTCI-CellList, the default spatial relation for SRS resource transmission is determined by the RS resource obtained from the SS/PBCH block reception that the UE uses to obtain MIB.
The base unit of claim 37, wherein for the aperiodic SRS scheduled by DCI, when no CORESET is configured on a scheduled CC; no TCI state is activated on the scheduled CC; the scheduled CC belongs to a simultaneousTCI-CellList configured for the UE; and at least one CORESET is configured for at least one CC belonging to the simultaneousTCI-CellList, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest CORESET-ID among all CORESET (s) configured in the active DL-BWP in the CC with the lowest CC index among all CCs configured with CORESET within the simultaneousTCI-CellList.
The base unit of claim 37, wherein for the aperiodic SRS scheduled by DCI, when no CORESET is configured on a scheduled CC; no TCI state is activated on the scheduled CC; the scheduled CC belongs to a simultaneousTCI-CellList configured for the UE; no CORESET is configured for all CCs within the simultaneousTCI-CellList; and at least one CC in the simultaneousTCI-CellList is configured with at least one TCI state for PDSCH, the default spatial relation for SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the CC with the lowest CC index among all CCs with activated TCI state for PDSCH within the simultaneousTCI-CellList.
The base unit of claim 37, wherein for the semi-persistent (SP) SRS activated by a SP SRS Activation/Deactivation MAC CE, when a higher layer parameter enableDefaultBeamPlForSRS is set as ‘enable’ , the SP SRS is associated with a CORESETPoolIndex by a field in the SP SRS Activation/Deactivation MAC CE or by the CORESET transmitting the DCI scheduling the PDSCH carrying the SP SRS Activation/Deactivation MAC CE, or a CORESETPoolIndex is directly configured in the SRS resource or SRS resource set containing the SRS resource.
The base unit of claim 37, wherein for the periodic SRS, when a higher layer parameter enableDefaultBeamPlForSRS is set as ’ enable’ , each periodic SRS resource or each periodic SRS resource set is associated with a CORESETPoolIndex.
The base unit of claim 44 or 45, wherein, when CORESET (s) are configured on a CC transmitting the SP or periodic SRS resource, the default spatial relation for SRS resource transmission is determined by the RS with ‘QCL-Type-D’ corresponding to the QCL assumption of the CORESET with the lowest ID among all the CORESETs configured with the same CORESETPoolIndex as that associated with the SP or periodic SRS resource.
The base unit of claim 44 or 45, wherein, when no CORESET is configured on a CC transmitting the SP or periodic SRS resource; and at least one TCI state is activated for PDSCH in the active DL-BWP in the CC, the default spatial relation for SRS resource transmission is determined by the activated TCI state with the lowest ID applicable to PDSCH in the active DL-BWP in the CC.
The base unit of claim 44 or 45, wherein, when no CORESET is configured on a CC transmitting the SP or periodic SRS resource; and no TCI state is activated for PDSCH in the active DL-BWP in the CC, the default spatial relation for SRS resource transmission is determined by the RS resource obtained from the SS/PBCH block reception that the UE uses to obtain MIB on the CC.