Default beam determination

Abstract

The invention relates to default beam determination. Methods and apparatus for determining a default beam are disclosed. In one embodiment, a method includes receiving an activation command of an activated BWP of a serving cell, where the activation command includes code points directed to TCI states, and at least one code point directed to two TCI states; and, when a scheduling offset between a downlink signal scheduled or triggered by the DCI and reception of a PDCCH carrying the DCI is less than a predetermined threshold, determining a default TCI state for reception of a corresponding downlink signal according to a TCI state for receiving the PDCCH or at least one TCI state pointed by a code point pointed to both TCI states.

Description

[0001] This application is a divisional application of the Chinese invention patent application "Default Beam Determination" with the PCT application number PCT / CN2020 / 084205, the international filing date of April 10, 2020, and the Chinese application number 202080099056.0, which entered the Chinese national phase on September 26, 2022. Technical Field

[0002] The subject matter disclosed herein generally relates to wireless communication, and more particularly to methods and apparatuses for determining default beams for receiving downlink signals transmitted from multiple TRPs. Background Art

[0003] The following abbreviations are defined herein, and at least some of them are cited in the following description: 3rd Generation Partnership Project (3GPP), European Telecommunications Standards Institute (ETSI), Frequency Division Duplexing (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 Duplexing (TDD), Time Division Multiplexing (TDM), User Entity / Device (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), Transmission and Reception Point (TRP), Multi-TRP (Multi-TRP or M-TRP), Frequency Range 2 (FR2), Quasi-Co-Location (QCL), Channel State Information Reference Signal (CSI-RS), Code Division Multiplexing (CDM), Transmission Configuration Indication (TCI), Control Resource Set (CORESET), Reference Signal (RS), Component Carrier (CC), Bandwidth Part (BWP), Non-Coherent Joint Transmission (NCJT), Media Access Control Control Element (MAC CE).

[0004] When the scheduling or triggering time offset is less than the threshold determined according to the UE capabilities report for in-carrier and cross-carrier scheduling of PDSCH and for triggering aperiodic CSI-RS resources across carriers, the default TCI state or QCL assumption for the reception of downlink signals such as for PDSCH and aperiodic CSI-RS resources is an important feature in NR Release 15 and Release 16. For example, for a PDSCH transmission scheduled by DCI, the TCI state for the reception of the PDSCH can be indicated by the 'transmission configuration indicator' field (i.e., the TCI field) included in the DCI. However, when the time offset between the reception of the DCI scheduling the PDSCH and the reception of the scheduled PDSCH transmission is less than the threshold determined according to the UE capabilities report (e.g., timeDurationForQCL), the UE will not have enough time to decode the DCI to obtain and change the TCI state for the reception of the scheduled PDSCH and adjust the beam to correspond to the obtained TCI state. Under this condition, one or more default TCI states must be determined in FR2. In other words, the capabilities reported by the UE (e.g., timeDurationForQCL) indicate the duration required by the UE for QCL determination.

[0005] In NR Release 16, a single-DCI-based multi-TRP DL transmission mode has been introduced for cell-edge UEs to achieve high throughput and / or reliable transmission. The PDSCH can be scheduled to be transmitted from two TRPs via two potential DL beams in the non-coherent joint transmission (NCJT) mode in FR2.

[0006] The higher layer parameter tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 indicates whether the 'transmission configuration indicator' field (i.e., the TCI field) is included in the DCI with format 1_1 or 1_2. The TCI field is used to indicate the TCI state for the reception of the scheduled PDSCH. The TCI field is 3 bits with eight possible values (also known as eight code points). Each code point can point to one or two TCI states. In particular, two TCI states can be pointed to by the TCI field in DCI format 1_1 and DCI format 1_2 for PDSCH reception in the NCJT mode. An activation command is received at the UE to indicate one or two TCI states pointed to by each of the eight code points.

[0007] In the following scenarios: (1) the scheduling offset (i.e., the time offset between the PDSCH scheduled by DCI and the reception of the PDCCH carrying the DCI) is less than the threshold for in-carrier scheduling of PDSCH reception, i.e., the PDCCH carrying the DCI and the scheduled PDSCH are transmitted in the same carrier; (2) a receive activation command (e.g., PDSCH TCI state activation / deactivation MAC CE) is received to indicate eight code points, at least one of which points to two TCI states (the other code points may point to one or two TCI states); and (3) the TCI field is configured to be present in the scheduling DCI for all CORESETs (i.e., tci-PresentInDCI is set to 'enabled (enabled)' for each of the CORESETs or tci-PresentInDCI-ForFormat1_2 is configured for all CORESETs), a default beam (i.e., default TCI state or default QCL assumption) for the reception of the scheduled PDSCH transmission is specified in NR Release 16. In particular, the TCI state pointed to by the lowest code point among the code points containing two different TCI states is determined as the default TCI state.

[0008] However, tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is configured according to the CORESET, while the PDSCH TCI state is activated according to the BWP by the MAC CE activation command. Therefore, there may be scenarios where tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is not configured for all CORESETs configured for the activated BWP (i.e., some CORESETs are configured with tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 set to 'enabled', while some other CORESETs are not configured with tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2). Under this condition, if at least one of the eight code points included in the activation command (e.g., PDSCH TCI state activation / deactivation MAC CE) points to two TCI states, it is not known what the default TCI state for the reception of the scheduled PDSCH is.

[0009] In addition, potential NCJT DL transmissions should also be considered to determine the default TCI state for the reception of cross-carrier scheduled aperiodic CSI-RS resources, i.e., the PDCCH carrying the triggering DCI and the triggered aperiodic CSI-RS resources are transmitted in different carriers.

[0010] The present disclosure aims to determine a default TCI state for receiving scheduled PDSCH and aperiodic CSI-RS resources for in-carrier and cross-carrier scheduling, taking into account potential single-DCI-based multi-TRP NCJT DL transmission. Summary of the Invention

[0011] A method and apparatus for determining a default beam are disclosed.

[0012] In one embodiment, a method includes: receiving an activation command for an active BWP of a serving cell, where the activation command includes a code point pointing to a TCI state, and at least one code point points to two TCI states; and when a scheduling offset between a downlink signal scheduled or triggered by DCI and the reception of the PDCCH carrying the DCI is less than a predetermined threshold, determining a default TCI state for receiving the corresponding downlink signal according to the TCI state for receiving the PDCCH or at least one TCI state pointed to by the code point pointing to two TCI states.

[0013] In one embodiment, the downlink signal is a PDSCH scheduled by DCI carried in a PDCCH transmitted on the same carrier as the carrier of the PDSCH. Under this condition, when tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is not configured for the CORESET of the DCI that schedules the transmission of the PDSCH, the default TCI state for receiving the scheduled PDSCH can be determined by the PDCCH QCL indication of the CORESET associated with the monitored search space having the lowest ControlResourceSetId in the nearest time slot within the active BWP of the serving cell where it is monitored, or can be determined by the first TCI state pointed to by the lowest code point among the code points pointing to two different TCI states. When tci-PresentInDCI is set to 'enabled' or tci-PresentInDCI-ForFormat1_2 is configured for the CORESET of the DCI that schedules the transmission of the PDSCH, the default TCI state for receiving the scheduled PDSCH can be determined by the TCI state pointed to by the lowest code point among the code points pointing to two different TCI states. Alternatively, regardless of whether tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is configured for the CORESET of the DCI that schedules the transmission of the PDSCH, the default TCI state for receiving the scheduled PDSCH can be determined by the first TCI state pointed to by the lowest code point among the code points pointing to two different TCI states.

[0014] In another embodiment, the downlink signal is a PDSCH scheduled by DCI carried in a PDCCH transmitted on a carrier different from the carrier of the PDSCH. Under this condition, regardless of whether tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is configured for the CORESET transmitting the DCI scheduling the PDSCH, the default TCI state for the reception of the scheduled PDSCH is determined by the TCI state pointed to by the lowest code point among the code points pointing to two different TCI states. Alternatively, regardless of whether tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is configured for the CORESET transmitting the DCI scheduling the PDSCH, the default TCI state for the reception of the scheduled PDSCH can be determined by the first TCI state pointed to by the lowest code point among the code points pointing to two different TCI states.

[0015] In some embodiments, the downlink signal is an aperiodic CSI-RS triggered by DCI carried in a PDCCH transmitted on a carrier different from the carrier of the aperiodic CSI-RS. Under this condition, when the time offset between the last symbol of the PDCCH carrying the triggering DCI and the first symbol of the aperiodic CSI-RS resource configured without higher layer parameter trs-Info and without higher layer parameter repetition is less than a predetermined threshold, the default TCI state for the reception of the triggered aperiodic CSI-RS resource can be determined by the first TCI state pointed to by the lowest code point among the code points pointing to two different TCI states.

[0016] In another embodiment, a remote unit includes: a receiver that receives an activation command for an active BWP of a serving cell, where the activation command includes a code point pointing to a TCI state, and at least one code point points to two TCI states; and a processor that, when the scheduling offset between a downlink signal scheduled or triggered by DCI and the reception of the PDCCH carrying the DCI is less than a predetermined threshold, determines the default TCI state for the reception of the corresponding downlink signal according to the TCI state for receiving the PDCCH or at least one TCI state pointed to by the code points pointing to two TCI states.

[0017] In one embodiment, a method includes: transmitting an activation command for an active BWP of a serving cell, where the activation command includes a code point pointing to a TCI state, and at least one code point points to two TCI states; and when a scheduling offset between a downlink signal scheduled or triggered by DCI and the reception of the PDCCH carrying the DCI is less than a predetermined threshold, determining a default TCI state for the reception of the corresponding downlink signal according to the TCI state for receiving the PDCCH or at least one TCI state pointed to by the code point pointing to two TCI states.

[0018] In yet another embodiment, a base station unit includes: a transmitter that transmits an activation command for an active BWP of a serving cell, where the activation command includes a code point pointing to a TCI state, and at least one code point points to two TCI states; and a processor that, when a scheduling offset between a downlink signal scheduled or triggered by DCI and the reception of the PDCCH carrying the DCI is less than a predetermined threshold, determines a default TCI state for the reception of the corresponding downlink signal according to the TCI state for receiving the PDCCH or at least one TCI state pointed to by the code point pointing to two TCI states. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] A more specific description of the embodiments briefly described above will be rendered by reference to specific embodiments illustrated in the drawings. It should be understood that these drawings only depict some embodiments and should not be considered as limiting the scope. The embodiments will be described and illustrated with additional distinctiveness and details by using the drawings, in which:

[0020] Figure 1 is a schematic flowchart illustrating an embodiment of the method;

[0021] Figure 2 is a schematic flowchart illustrating yet another embodiment of the method; and

[0022] Figure 3 is a schematic block diagram illustrating a device according to an embodiment. DETAILED DESCRIPTION

[0023] As those skilled in the art will appreciate, certain aspects of the embodiments may be embodied as a system, apparatus, method, or program product. Accordingly, the embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects, which software or hardware aspects may generally be referred to herein as "circuitry", "module", or "system". Additionally, the 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, hereinafter referred to as "code". The storage device may be tangible, non-transitory, and / or non-transmissive. The storage device may not embody a signal. In certain embodiments, the storage device merely takes a signal for accessing the code.

[0024] Certain functional units described in this specification may be marked as "modules" for more particularly emphasizing their independent implementation. For example, a module may be implemented as a hardware circuit including 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, etc.

[0025] A module may also be implemented in code and / or software for execution by various types of processors. The identification of a module in code may, for example, include one or more physical or logical blocks of executable code, which may be organized, for example, as objects, procedures, or functions. However, the executable files identifying the module need not be physically located together, but may include different instructions stored in different locations, which, when logically joined together, include the module and implement the stated purpose of the module.

[0026] In fact, 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, the operational data may be identified and illustrated herein within a module and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set or may be distributed over different locations, including over different computer-readable storage devices. In cases 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.

[0027] Any combination of one or more computer-readable media can be utilized. A computer-readable medium can be a computer-readable storage medium. A computer-readable storage medium can be a storage device that stores code. The storage device can be, by way of example, but not necessarily, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micro-mechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

[0028] A non-exhaustive list of more specific examples of storage devices will include the following: an electrical connection having one or more wires, a portable computer floppy disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a 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 can be any tangible medium that is capable of containing or storing a program for use by or in connection with an instruction execution system, apparatus, or device.

[0029] The code for performing the operations of the embodiments can include any number of lines and can be written in any combination of one or more programming languages including object-oriented programming languages such as Python, Ruby, Java, Smalltalk, C++, and the like, conventional procedural programming languages such as the "C" programming language, and / or machine languages such as assembly language. The code can 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 a remote computer or server. In the last scenario, the remote computer can 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 can make a connection to an external computer (e.g., using an Internet service provider through the Internet).

[0030] References throughout the specification to "one embodiment", "an embodiment", or similar language mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, unless otherwise explicitly specified, the appearances of the phrases "in one embodiment", "in an embodiment", and similar language throughout the specification may, but do not necessarily, all refer to the same embodiment, but rather mean "one or more but not all embodiments". Unless otherwise explicitly specified, the terms "comprises", "comprising", "has", and variations thereof mean "including but not limited to". Unless explicitly specified, an enumeration of items does not imply that any or all of the items are mutually exclusive. Unless otherwise explicitly specified, the terms "a", "an", and "the" also refer to "one or more".

[0031] In addition, the features, structures, or characteristics of the 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 the embodiments. However, those skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific details or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the embodiments.

[0032] Aspects of different embodiments are described below with reference to the schematic flowcharts 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 flowcharts and / or schematic block diagrams, and combinations of blocks in the schematic flowcharts and / or schematic block diagrams, can be implemented by code. This code can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions executed via the processor of the computer or other programmable data processing apparatus create a device for implementing the functions specified for one or more blocks in the schematic flowcharts and / or schematic block diagrams.

[0033] The code can also be stored in a storage device that can direct a computer, other programmable data processing apparatus, or other device to operate in a particular manner, such that the instructions stored in the storage device produce an article of manufacture including instructions for implementing the functions specified in the block or blocks of the schematic flowcharts and / or schematic block diagrams.

[0034] The code can also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on that computer, other programmable apparatus, or other device to produce a computer-implemented process, such that the code executed on the computer or other programmable apparatus provides a process for implementing the functions specified in the block or blocks of the flowchart and / or block diagram.

[0035] The schematic flowcharts 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 flowcharts and / or schematic block diagrams may represent a module, segment, or portion of code that includes one or more executable instructions for implementing the specified logical function.

[0036] It should also be noted that, in some alternative embodiments, the functions annotated in the boxes may not occur in the order indicated in the respective figures. For example, depending on the functionality involved, two consecutively shown boxes may be executed substantially simultaneously, or sometimes these boxes may be executed in the reverse order. Other steps and methods equivalent in function, logic, or effect to one or more boxes or portions thereof of the illustrated figures may be contemplated.

[0037] Although various arrow types and line types may be employed in the flowcharts and / or block diagrams, they are understood not to limit the scope of the corresponding embodiments. In fact, some arrows or other connectors may be used to indicate only the logical flow of the depicted embodiments. For example, an arrow may indicate a waiting or monitoring period of unspecified duration between the enumerated steps of the depicted embodiment. It will also be noted that each box of the block diagram and / or flowchart, and combinations of the boxes in the block diagram and / or flowchart, can be implemented by a system based on dedicated hardware or a combination of dedicated hardware and code that performs the specified functions or actions.

[0038] The description of the elements in each figure may refer to the elements of the previous figure. The same reference numerals in all figures refer to the same elements, including alternative embodiments of the same elements.

[0039] The first embodiment relates to determining a default TCI state for in-carrier PDSCH scheduling in the NCJT mode.

[0040] According to the first embodiment, a default TCI state for the reception of the scheduled PDSCH is determined when the following three conditions are met:

[0041] (1) The DCI carried in the PDCCH schedules the PDSCH transmitted on the same carrier as the carrier of the PDCCH (i.e., in-carrier scheduling of the PDSCH). The scheduled PDSCH may be transmitted from one or two TRPs. The scheduling offset (i.e., the time offset between the reception of the scheduled PDSCH and the PDCCH carrying the DCI) is less than the threshold 'timeDurationForQCL'.

[0042] (2) The PDCCH is transmitted in one of the CORESETs within the active BWP of the serving cell monitored by the UE. Some CORESETs are configured with tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 set to 'enabled', while some other CORESETs are not configured with tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2.

[0043] (3) Receive an activation command (e.g., PDSCH TCI state activation / deactivation MAC CE) to indicate eight code points pointing to the TCI state to be activated. At least one code point points to two different TCI states; and each of the other code points can point to one or two TCI states.

[0044] According to the first embodiment, for a CORESET of a DCI for a transmitted scheduled PDSCH for which tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is not configured therefor and for a CORESET of a DCI for a transmitted scheduled PDSCH for which tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 configured to be 'enabled' is configured therefor, the default TCI state for reception of the scheduled PDSCH is determined differently. Note that a CORESET identifies a set of time-frequency resources for the transmission of a PDCCH and each CORESET has a ControlResourceSetId.

[0045] In particular, for a CORESET of a DCI for a transmitted scheduled PDSCH for which tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is not configured therefor, the default TCI state for reception of the scheduled PDSCH is determined by the TCI state for reception of the PDCCH. In particular, the UE may assume that the DM-RS ports of the scheduled PDSCH of the serving cell are quasi-co-located (hereinafter, abbreviated as "QCLed") with the RS with respect to the QCL parameter, and the QCL parameter is used for the PDCCH QCL indication of the CORESET associated with the monitored search space having the lowest ControlResourceSetId in the most recent time slot within the active BWP of the serving cell in which one or more CORESETS are monitored by the UE.

[0046] On the other hand, for a CORESET of DCI that transmits the scheduled PDSCH with tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 configured to 'enabled', the default TCI state for the reception of the scheduled PDSCH is determined by one of the TCI states activated in the activation command (e.g., PDSCH TCI state activation / deactivation MAC CE). In particular, when at least one of the configured TCI states of the serving cell for the scheduled PDSCH contains 'QCL-TypeD', the UE may assume that the DM-RS ports of the scheduled PDSCH of the serving cell are QCLed with the RS with respect to the QCL parameters associated with the TCI state pointed to by the lowest code point among the code points pointing to two different TCI states. Incidentally, when none of the configured TCI states of the serving cell for the scheduled PDSCH contains 'QCL-TypeD', the UE shall obtain other QCL assumptions from the indicated TCI state of its scheduled PDSCH regardless of the time offset between the reception of the PDSCH and the corresponding DL DCI and does not have to determine the default beam.

[0047] The statement "QCLed with the RS with respect to the QCL parameters associated with the TCI state" is further explained as follows:

[0048] The UE can be configured with a list of up to M TCI state configurations to decode the PDSCH based on the detected PDCCH of the DCI intended for the UE and a given serving cell, where M depends on the UE capability. The TCI states are configured by the following RRC signaling:

[0049]

[0050] Each TCI state contains parameters for configuring the quasi-colocation (QCL) relationship between one or two downlink reference signals (i.e., RS) and the DM-RS ports of the PDSCH, the DM-RS ports of the PDCCH, or the CSI-RS ports of the CSI-RS resources. The quasi-colocation relationship is configured by the higher layer parameter qcl-Type1 for the first downlink RS and qcl-Type2 (if configured) for the second downlink RS. For the case of two downlink RSs, the QCL types shall be different regardless of whether the reference is to the same downlink RS or different downlink RSs. The quasi-colocation type (i.e., QCL parameter) corresponding to each downlink RS is given by the higher layer parameter qcl-Type in QCL-Info and can take one of the following values:

[0051] 'QCL-TypeA': {Doppler frequency shift, Doppler spread, average delay, delay spread}

[0052] 'QCL-TypeB': {Doppler shift, Doppler spread}

[0053] 'QCL-TypeC': {Doppler shift, average delay}

[0054] 'QCL-TypeD': {Spatial Rx parameter}

[0055] For example, if the TCI state is configured as TCI state = {CSI-RS#1, QCL-TypeA; CSI-RS#2, QCL-TypeD} and it is indicated for PDSCH reception, this means that the UE can assume that the Doppler shift, Doppler spread, average delay, and delay spread of the DM-RS ports of the PDSCH are the same as those estimated by CSI-RS#1, and the UE can use the same spatial Rx parameters as those used for receiving CSI-RS#2 to receive the PDSCH and the corresponding DM-RS ports. We can say that the UE can assume that the DM-RS ports of the scheduled PDSCH are quasi-co-located (i.e., QCLed) with CSI-RS#1 with respect to 'QCL-TypeA', and quasi-co-located with CSI-RS#2 with respect to 'QCL-TypeD' (or abbreviated as "QCLed with the RS with respect to the QCL parameters associated with the indicated TCI state"). In other words, the QCL assumption of the DM-RS ports of the scheduled PDSCH (for PDSCH reception) is determined according to the indicated TCI state.

[0056] The activation command received by the UE (e.g., PDSCH TCI state activation / deactivation MAC CE) is used to map up to eight different TCI states to the code points of the 'transmission configuration indication' (i.e., TCI field) in the DCI field of one DL BWP of the serving cell. When the UE supports two TCI states pointed to by the code points of the TCI field, the activation command can be used to map up to 8 combinations of one or two different TCI states to the code points of the TCI field.

[0057] An example of the first embodiment is described as follows:

[0058] Assume that the following PDSCH TCI state activation / deactivation MAC CE is received for the currently active BWP of the serving cell, and at least one of the configured TCI states for the serving cell of the scheduled PDSCH contains 'QCL-TypeD':

[0059] {

[0060] The TCI field with a code point value of '000' points to TCI state #1,

[0061] The TCI field with a code point of '001' points to TCI state #2.

[0062] The TCI field with a code point of '010' points to TCI state #5 and TCI state #8.

[0063] The TCI field with a code point of '011' points to TCI state #11.

[0064] The TCI field with a code point of '100' points to TCI state #38.

[0065] The TCI field with a code point of '101' points to TCI state #52.

[0066] The TCI field with a code point of '110' points to TCI state #65 and TCI state #88.

[0067] The TCI field with a code point of '111' points to TCI state #110

[0068] }

[0069] Configure three CORESETs for the active BWP of the serving cell for the UE, such as CORESET#1, CORESET#2, and CORESET#3, where tci-PresentInDCI is not configured for CORESET#1 and CORESET#2 and tci-PresentInDCI is set to 'enabled' for CORESET#3.

[0070] If the UE receives a DCI with format 1_1 that schedules a PDSCH transmission with a scheduling offset less than the threshold timeDurationForQCL, the default TCI state must be determined.

[0071] According to the first embodiment, if the UE receives a DCI with format 1_1 transmitted from CORESET#1 that schedules a PDSCH with a scheduling offset less than the threshold timeDurationForQCL, the UE may assume that the DM-RS ports of the scheduled PDSCH are QCLed with the QCL parameters associated with the TCI state of the CORESET associated with the monitored search space having the lowest ControlResourceSetId in the nearest time slot monitored by the UE for one or more CORESETs within the active BWP of the serving cell. That is, the default TCI state is determined by the received TCI state of the PDCCH associated with the monitored search space having the lowest ControlResourceSetId in the nearest time slot monitored by the UE for one or more CORESETs within the active BWP of the serving cell, regardless of the activation command.

[0072] On the other hand, according to the first embodiment, if the UE receives DCI transmitted from CORESET #3 that schedules the PDSCH with a scheduling offset less than the threshold timeDurationForQCL, the UE may assume that the DM-RS ports of the scheduled PDSCH are QCLed with the RS with respect to the QCL parameters associated with TCI state #5 and TCI state #8, because the code point '010' is the lowest code point that points to two different TCI states.

[0073] The second embodiment relates to another option for determining the default TCI state for in-carrier PDSCH scheduling in the NCJT mode.

[0074] According to the second embodiment, the default TCI state for the reception of the scheduled PDSCH is determined when the same three conditions as in the first embodiment are met.

[0075] The second embodiment is different from the first embodiment in that for the CORESET of the DCI that transmits and schedules the PDSCH and for which tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is not configured therefor, the default TCI state for the reception of the scheduled PDSCH is determined in a different manner.

[0076] According to the first embodiment, it is required that the UE maintains at least 3 different default beams for PDSCH reception, namely the beam for the CORESET and the two beams corresponding to the two default TCI states. This requires high capabilities of the UE. To reduce the number of beams maintained by the UE, according to the second embodiment, for the CORESET of the DCI that transmits and schedules the PDSCH and for which tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is not configured therefor, the default TCI state for the reception of the scheduled PDSCH is determined by one of the TCI states activated in an activation command (e.g., PDSCH TCI state activation / deactivation MAC CE). In particular, when at least one of the configured TCI states of the serving cell for the scheduled PDSCH contains 'QCL-TypeD', the UE may assume that the DM-RS ports of the scheduled PDSCH of the serving cell are QCLed with the RS with respect to the QCL parameters associated with one of the TCI states (preferably the first TCI state) pointed to by the lowest code point among the code points that point to two different TCI states.

[0077] For a CORESET of DCI that transmits a scheduled PDSCH with tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 configured to 'enabled' for this, the default TCI state for the reception of the scheduled PDSCH is determined in the same manner as in the first embodiment. That is, when at least one of the TCI states configured for the serving cell of the scheduled PDSCH includes 'QCL-TypeD', the UE may assume that the DM-RS ports of the scheduled PDSCH of the serving cell are QCLed with the RS with respect to the QCL parameters associated with the TCI state pointed to by the lowest code point among the code points pointing to two different TCI states. Generally, according to the second embodiment, at most two different beams corresponding to two default TCI states are maintained by the UE.

[0078] An example of the second embodiment is described as follows:

[0079] It is assumed that the same PDSCH TCI state activation / deactivation MAC CE as in the first embodiment is received for the currently active BWP of the serving cell.

[0080] Similarly to the first embodiment, three CORESETs are configured for the active BWP of the serving cell of the UE, such as CORESET#1, CORESET#2, and CORESET#3, where tci-PresentInDCI is not configured for CORESET#1 and CORESET#2 and tci-PresentInDCI is set to 'enabled' for CORESET#3.

[0081] According to the second embodiment, if the UE receives a DCI with format 1_1 transmitted from CORESET#1 or CORESET#2 that schedules a PDSCH with a scheduling offset less than the threshold timeDurationForQCL, the UE may assume that the DM-RS ports of the scheduled PDSCH are QCLed with the RS with respect to the QCL parameters associated with TCI state #5 or TCI state #8. TCI state #5 is preferred because it is the first TCI state among the TCI states pointed to by the lowest code point pointing to two different TCI states.

[0082] According to the second embodiment, if the UE receives a DCI with format 1_1 transmitted from CORESET#3 that schedules a PDSCH with a scheduling offset less than the threshold timeDurationForQCL, the UE may assume that the DM-RS ports of the scheduled PDSCH are QCLed with the RS with respect to the QCL parameters associated with TCI state #5 and TCI state #8, which is the same as in the first embodiment.

[0083] The third embodiment relates to another option for determining the default TCI state for in-carrier PDSCH scheduling in the NCJT mode.

[0084] According to the third embodiment, the default TCI state for the reception of the scheduled PDSCH is determined when the same three conditions as in the first embodiment are met.

[0085] The third embodiment is different from the first or second embodiment in that for both the CORESET of the DCI for the transmit-scheduled PDSCH for which tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is not configured for this and the CORESET of the DCI for the transmit-scheduled PDSCH for which tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is configured with the setting 'enabled' for this, the default TCI state for the reception of the scheduled PDSCH is determined in the same way.

[0086] As described above, according to the first embodiment, the UE needs to maintain three different default beams for PDSCH reception, while according to the second embodiment, the UE needs to maintain two different default beams for PDSCH reception. According to the third embodiment, the UE will only need to maintain one default beam for PDSCH reception. According to the third embodiment, for the CORESET of the DCI for the transmit-scheduled PDSCH (regardless of whether tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is configured for the CORESET), the default TCI state for the reception of the scheduled PDSCH is determined by one of the TCI states activated in the activation command (e.g., the PDSCH TCI state activation / deactivation MAC CE). In particular, when at least one of the configured TCI states of the serving cell for the scheduled PDSCH includes 'QCL-TypeD', the UE may assume that the DM-RS ports of the scheduled PDSCH of the serving cell are QCLed with the RS with respect to the QCL parameters associated with one of the TCI states (preferably the first TCI state) pointed to by the lowest code point among the code points pointing to two different TCI states.

[0087] An example of the third embodiment is described as follows:

[0088] Assume that the same PDSCH TCI state activation / deactivation MAC CE as in the first embodiment is received for the currently active BWP of the serving cell.

[0089] Similar to the first embodiment, three CORESETs are configured for the active BWP of the serving cell for the UE, such as CORESET #1, CORESET #2, and CORESET #3, where tci-PresentInDCI is not configured for CORESET #1 and CORESET #2 and tci-PresentInDCI is set to 'enabled' for CORESET #3.

[0090] According to the third embodiment, if the UE receives a DCI with format 1_1 transmitted from CORESET #1 or CORESET #2 or CORESET #3 that schedules a PDSCH with a scheduling offset less than the threshold timeDurationForQCL, the UE may assume that the DM-RS ports of the scheduled PDSCH are QCLed with the RS with respect to the QCL parameters associated with TCI state #5 or TCI state #8. TCI state #5 is preferred because it is the first TCI state among the TCI states pointed to by the lowest code point that points to two different TCI states.

[0091] The fourth embodiment relates to determining a default TCI state for cross-carrier scheduling in the NCJT mode.

[0092] According to the fourth embodiment, a default TCI state for the reception of the scheduled PDSCH is determined when the following three conditions are met:

[0093] (1) The DCI carried in the PDCCH schedules a PDSCH transmission on a carrier different from the carrier of the PDCCH (i.e., a cross-carrier scheduled PDSCH). In other words, the PDCCH carrying the scheduling DCI is received on one component carrier, while the PDSCH scheduled by this DCI is received on another component carrier. The time offset between the reception of the scheduled PDSCH and the DL DCI is less than the threshold timeDurationForQCL. timeDurationForQCL is determined based on the subcarrier spacing of the scheduled PDSCH. If the subcarrier spacing (μ PDCCH ) of the carrier transmitting the PDCCH is less than the subcarrier spacing (μ PDSCH ) of the carrier transmitting the PDSCH, i.e., μ PDCCH < μ PDSCH , an additional timing delay d is added to timeDurationForQCL as defined in NR version 15.

[0094] (2) Transmit PDCCH in one of the CORESETs within the active BWP of the serving cell monitored by the UE. Some CORESETs are configured with tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 set to 'enabled', while some other CORESETs are not configured with tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2.

[0095] (3) Receive an activation command (e.g., PDSCH TCI state activation / deactivation MAC CE) to indicate eight code points pointing to the TCI states to be activated. At least one code point points to two different TCI states; and each of the other code points can point to one or two TCI states.

[0096] According to the fourth embodiment, for the CORESET that transmits the DCI for scheduling the PDSCH (regardless of whether it is configured with tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2), the default TCI state for the reception of the scheduled PDSCH is determined by one of the TCI states activated in the activation command (e.g., PDSCH TCI state activation / deactivation MAC CE). In particular, when at least one of the configured TCI states of the serving cell for the scheduled PDSCH contains 'QCL-TypeD', the UE may assume that the DM-RS ports of the scheduled PDSCH of the serving cell are QCLed with the RS with respect to the QCL parameters associated with the TCI state pointed to by the lowest code point among the code points pointing to two different TCI states. Incidentally, when none of the configured TCI states of the serving cell for the scheduled PDSCH contains 'QCL-TypeD', the UE should obtain other QCL assumptions from the indicated TCI state of its scheduled PDSCH, regardless of the time offset between the reception of the PDSCH and the corresponding DL DCI and does not have to determine the default beam.

[0097] An example of the fourth embodiment is described as follows:

[0098] The UE receives DCI carried in the PDCCH transmitted on CC#1 that schedules the PDSCH transmitted on CC#2. Assume that the following PDSCH TCI state activation / deactivation MAC CE is received for the current active BWP of CC#2, and at least one of the configured TCI states of the serving cell for the scheduled PDSCH contains 'QCL-TypeD':

[0099] {

[0100] The TCI field with the code point of '000' points to TCI state #1.

[0101] The TCI field with the code point of '001' points to TCI state #2.

[0102] The TCI field with the code point of '010' points to TCI state #5 and TCI state #8.

[0103] The TCI field with the code point of '011' points to TCI state #11.

[0104] The TCI field with the code point of '100' points to TCI state #38.

[0105] The TCI field with the code point of '101' points to TCI state #52.

[0106] The TCI field with the code point of '110' points to TCI state #65 and TCI state #88.

[0107] The TCI field with the code point of '111' points to TCI state #110.

[0108] }

[0109] When the scheduling offset is less than timeDurationForQCL, the UE may assume that the DM-RS ports of the scheduled PDSCH are QCLed with the RS with respect to the QCL parameters associated with TCI state #5 and TCI state #8.

[0110] The fifth embodiment relates to another option for determining the default TCI state for cross-carrier PDSCH scheduling in the NCJT mode.

[0111] According to the fifth embodiment, the default TCI state for the reception of the scheduled PDSCH is determined when the same three conditions as in the fourth embodiment are met.

[0112] The UE may report different UE capabilities for different cells. The fifth embodiment takes this into account. For example, when the UE is able to support NCJT in CC#2 (on which the scheduled PDSCH will be transmitted) but not in CC#1 (on which the PDCCH carrying the scheduling DCI is transmitted), if the scheduling offset is less than the threshold, the UE may receive the PDSCH with a single default TCI state.

[0113] When the UE receives the DCI carried in the PDCCH on a cell without NCJT capability for scheduling the PDSCH on another cell and the scheduling offset is less than the threshold, according to the fifth embodiment, the default TCI state for the reception of the scheduled PDSCH is determined by one of the TCI states activated in the activation command (e.g., PDSCH TCI state activation / deactivation MAC CE). In particular, when at least one of the configured TCI states of the serving cell for the scheduled PDSCH contains 'QCL-TypeD', the UE may assume that the DM-RS ports of the scheduled PDSCH of the serving cell are QCLed with the RS with respect to the QCL parameters associated with one of the TCI states (preferably the first TCI state) pointed to by the lowest code point among the code points pointing to two different TCI states.

[0114] An example of the fifth embodiment is described as follows:

[0115] The UE receives the DCI carried in the PDCCH transmitted on CC#1 that schedules the PDSCH transmitted on CC#2. Assume that the same PDSCH TCI state activation / deactivation MAC CE as in the fourth embodiment is received for the currently active BWP of CC#2.

[0116] According to the fifth embodiment, the UE may assume that the DM-RS ports of the scheduled PDSCH are QCLed with the RS with respect to the QCL parameters associated with TCI state #5 or TCI state #8. TCI state #5 is preferred because it is the first TCI state among the TCI states pointed to by the lowest code point among the code points pointing to two different TCI states.

[0117] The sixth embodiment relates to determining the default TCI state for cross-carrier aperiodic CSI-RS resource triggering.

[0118] Different from the PDSCH transmission in the NCJT mode, each CSI-RS resource can be transmitted from only one TRP in a given time slot. Therefore, the default TCI state for cross-carrier aperiodic CSI-RS resource triggering should be a single default TCI state.

[0119] According to the sixth embodiment, the default TCI state for the reception of the triggered CSI-RS is determined when the following three conditions are met:

[0120] (1)The DCI carried in the PDCCH triggers an aperiodic CSI-RS transmission on a carrier different from the carrier of the PDCCH (i.e., cross-carrier triggered aperiodic CSI-RS). In other words, the PDCCH carrying the triggering DCI is received on one component carrier, while the aperiodic CSI-RS resource triggered by this DCI is received on another component carrier. The subcarrier spacing (μ PDCCH ) of the carrier transmitting the PDCCH is less than the subcarrier spacing ( μCSIRS ) of the carrier transmitting the CSI-RS, i.e., μ PDCCH < μ CSIRS . The scheduling offset between the last symbol of the PDCCH carrying the triggering DCI and the first symbol of the aperiodic CSI-RS resource configured without the higher layer parameter trs-Info and without the higher layer parameter repetition is less than the threshold beamSwitchTiming + d in terms of PDCCH symbols reported by the UE. The reported value of beamSwitchTiming indicates the duration for the UE to perform beam switching and is one of the values {14, 28, 48}. The beam switching timing delay d is defined in the following table (Table 5.2.1.5.1a-1 of TS38.214):

[0121] Table 5.2.1.5.1a-1: Additional beam switching timing delay d

[0122]

[0123] (2)There is no other DL signal with the indicated TCI state in the same symbol as the CSI-RS, and no CORESET is configured for the BWP on the cell where the aperiodic CSI-RS will be received.

[0124] (3)Receive an activation command (e.g., PDSCH TCI state activation / deactivation MAC CE) to indicate eight code points pointing to the TCI states to be activated. At least one code point points to two different TCI states; and each of the other code points can point to one or two TCI states.

[0125] Incidentally, condition (2) is included to indicate that to satisfy only condition (2), it is necessary to determine the default TCI state. If there is any other DL signal with an indicated TCI state in the same symbol as the CSI-RS, the UE also applies the QCL assumption of the other DL signal when receiving the aperiodic CSI-RS. The other DL signal refers to the PDSCH scheduled with an offset greater than or equal to the threshold timeDurationForQCL as defined in [13, TS38.306], the aperiodic CSI-RS scheduled with an offset greater than or equal to the UE-reported threshold beamSwitchTiming + d*μ PDCCH / μ PDSCH when the reported value of beamSwitchTiming is one of {14, 28, 48}, the aperiodic CSI-RS scheduled with an offset greater than or equal to the UE-reported threshold beamSwitchTiming + d*μ

[0126] the aperiodic CSI-RS scheduled with an offset greater than or equal to 48 + d when the reported value of beamSwitchTiming is one of {224, 336}, the periodic CSI-RS, and the semi-persistent CSI-RS. If at least one CORESET is configured for the BWP in which the aperiodic CSI-RS will be received, when receiving the aperiodic CSI-RS, the UE applies the QCL assumption of the CORESET associated with the monitored search space with the lowest ControlResourceSetId in the most recent time slot of one or more CORESETS within the active BWP for monitoring the serving cell.

[0127] An example of the sixth embodiment is described as follows:

[0128] The UE receives DCI carried in a PDCCH transmitted on CC#1 that triggers the transmission of an aperiodic CSI-RS resource on CC#2. The following PDSCH TCI state activation / deactivation MAC CE is received for the currently active BWP of CC#2, and at least one of the configured TCI states of the serving cell for the triggered CSI-RS contains 'QCL-TypeD':

[0129] {

[0130] The TCI field with the code point of '000' points to TCI state #1,

[0131] The TCI field with the code point of '001' points to TCI state #2,

[0132] The TCI field with the code point of '010' points to TCI state #5 and TCI state #8,

[0133] The TCI field with the code point of '011' points to TCI state #11,

[0134] The TCI field with the code point of '100' points to TCI state #38,

[0135] The TCI field with the code point of '101' points to TCI state #52,

[0136] The TCI field with the code point of '110' points to TCI state #65 and TCI state #88,

[0137] The TCI field with the code point of '111' points to TCI state #110

[0138] }

[0139] According to the sixth embodiment, when the trigger offset between the last symbol of the PDCCH carrying the triggering DCI and the first symbol of the aperiodic CSI-RS resource configured without the higher layer parameter trs-Info and without the higher layer parameter repetition is less than the threshold beamSwitchTiming reported by the UE plus d in terms of PDCCH symbols, the UE may assume that the triggered CSI-RS is RSQCLed with respect to the QCL parameters associated with TCI state #5 or TCI state #8. TCI state #5 is preferred because it is the first TCI state among the TCI states pointed to by the lowest code point that points to two different TCI states.

[0140] Figure 1 is a schematic flowchart illustrating an embodiment of method 100 according to the present application. In some embodiments, method 100 is performed by a device such as a base station unit. In certain embodiments, method 100 may be performed by a processor executing program code such as, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, an FPGA, etc.

[0141] Method 100 may include 102 receiving an activation command for an activated BWP of a serving cell, where the activation command includes a code point pointing to a TCI state, and at least one code point points to two TCI states; and when a scheduling offset between a downlink signal scheduled or triggered by DCI and the reception of the PDCCH carrying the DCI is less than a predetermined threshold, determining 104 a default TCI state for the reception of the corresponding downlink signal according to the TCI state for receiving the PDCCH or at least one TCI state pointed to by the code point pointing to two TCI states.

[0142] Figure 2 FIG. is a schematic flowchart illustrating an embodiment of method 200 according to the present application. In some embodiments, method 200 is performed by a device such as a base station unit. In certain embodiments, method 200 may be performed by a processor executing program code such as, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, an FPGA, etc.

[0143] Method 200 may include 202 transmitting an activation command for an activated BWP of a serving cell, where the activation command includes a code point pointing to a TCI state, and at least one code point points to two TCI states; and when a scheduling offset between a downlink signal scheduled or triggered by DCI and the reception of the PDCCH carrying the DCI is less than a predetermined threshold, determining 204 a default TCI state for the reception of the corresponding downlink signal according to the TCI state for receiving the PDCCH or at least one TCI state pointed to by the code point pointing to two TCI states.

[0144] Figure 3 FIG. is a schematic block diagram of a device according to an embodiment.

[0145] Reference Figure 3 , the UE (i.e., the remote unit) includes a processor, a memory, and a transceiver. The processor implements the functions, processes, and / or methods proposed in Figure 1 . The gNB (i.e., the base station unit) includes a processor, a memory, and a transceiver. The processor implements the functions, processes, and / or methods proposed in Figure 2 . The layers of the radio interface protocol may be implemented by the processor. The memory is connected to the processor to store various pieces of information for driving the processor. The transceiver is connected to the processor to transmit and / or receive radio signals. Needless to say, the transceiver may be implemented as a transmitter for transmitting radio signals and a receiver for receiving radio signals.

[0146] The memory may be located inside or outside the processor and connected to the processor by various well-known means.

[0147] In the above embodiments, the components and features of the embodiments are combined in a predetermined form. Unless otherwise explicitly stated, each component or function should be considered an option. Each component or feature can be implemented without being associated with other components or features. Additionally, embodiments can be configured by associating some components and / or features. The order of operations described in the embodiments can be changed. Some components or features of any embodiment can be included in another embodiment or replaced with corresponding components and features of another embodiment. It is obvious that claims not explicitly recited in the claims are combined to form embodiments or included in new claims.

[0148] Embodiments can be implemented by hardware, firmware, software, or a combination thereof. In the case of implementation by hardware, according to the hardware implementation, the exemplary embodiments described herein can 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, microcontrollers, microprocessors, etc.

[0149] Embodiments can be practiced in other specific forms. The described embodiments are to be considered in all respects only illustrative and not restrictive. The scope of the present invention is thus indicated by the appended claims rather than by the foregoing description. All changes that fall within the equivalent meaning and scope of the claims should be covered within their scope.

Claims

1. A method performed at a base station unit, comprising: Transmitting an activation command for an activated bandwidth part BWP of a serving cell, wherein the activation command includes code points pointing to one or more transmission configuration indication TCI states, and at least one code point points to two TCI states; and When a scheduling offset between reception of a physical downlink control channel PDCCH carrying downlink control information DCI and a corresponding physical downlink shared channel PDSCH scheduled by the DCI and transmitted on the same carrier as the PDCCH is less than a predetermined threshold, determining at least one of one or more default TCI states for reception of the scheduled PDSCH according to at least one TCI state pointed to by the code point pointing to two TCI states.

2. The method according to claim 1, wherein When tci - PresentInDCI is set to "enabled" or tci - PresentInDCI - ForFormat1_2 is configured for the CORESET transmitting the DCI scheduling the PDSCH, the default TCI state for reception of the scheduled PDSCH is determined by the TCI state pointed to by the lowest code point among the code points pointing to two different TCI states.

3. The method according to claim 1, wherein When neither tci - PresentInDCI nor tci - PresentInDCI - ForFormat1_2 is configured for the CORESET transmitting the DCI scheduling the PDSCH, the default TCI state for reception of the scheduled PDSCH is determined by a first TCI state pointed to by the lowest code point among the code points pointing to two different TCI states.

4. The method according to claim 1, wherein Regardless of whether tci - PresentInDCI or tci - PresentInDCI - ForFormat1_2 is configured for the CORESET transmitting the DCI scheduling the PDSCH, the default TCI state for reception of the scheduled PDSCH is determined by a first TCI state pointed to by the lowest code point among the code points pointing to two different TCI states.

5. A base station unit, comprising: A transmitter that transmits an activation command for an activated bandwidth part BWP of a serving cell, wherein the activation command includes code points pointing to one or more transmission configuration indication TCI states, and at least one code point points to two TCI states; and A processor that, when a scheduling offset between reception of a physical downlink control channel PDCCH carrying downlink control information DCI and a corresponding physical downlink shared channel PDSCH scheduled by the DCI and transmitted on the same carrier as the PDCCH is less than a predetermined threshold, determines at least one of one or more default TCI states for reception of the scheduled PDSCH according to at least one TCI state pointed to by the code point pointing to two TCI states.

6. The base station unit according to claim 5, wherein, When tci-PresentInDCI is set to "enabled" or tci-PresentInDCI-ForFormat1_2 is configured for the CORESET of the DCI that transmits the scheduling for the PDSCH, the default TCI state for the reception of the scheduled PDSCH is determined by the TCI state pointed to by the lowest code point among the code points that point to two different TCI states.

7. The base station unit according to claim 5, wherein When tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is not configured for the CORESET of the DCI that transmits the scheduling for the PDSCH, the default TCI state for the reception of the scheduled PDSCH is determined by the first TCI state pointed to by the lowest code point among the code points that point to two different TCI states.

8. The base station unit according to claim 5, wherein, Regardless of whether tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is configured for the CORESET of the DCI that transmits the scheduling for the PDSCH, the default TCI state for the reception of the scheduled PDSCH is determined by the first TCI state pointed to by the lowest code point among the code points that point to two different TCI states.

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