Default beam determination

Abstract

A method and apparatus for determining a default beam are disclosed. A method includes receiving an activation command of an activated BWP of a serving cell, wherein the activation command contains code points pointing to TCI states, and at least one code point points to two TCI states; and, when a scheduling offset between a downlink signal scheduled or triggered by a 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 the TCI state for receiving the PDCCH or at least one TCI state pointed to by the code points pointing to the two TCI states.

Description

Technical Field

[0001] The subject matter disclosed herein relates generally to wireless communications, and more specifically to methods and apparatus for determining a default beam for receiving downlink signals transmitted from multiple TRPs. Background Art

[0002] The following abbreviations are defined herein, and at least some of them are referred to in the following description: 3rd 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) LCD), Light Emitting Diode (LED), Organic LED (OLED), Orthogonal Frequency Division Multiplexing (OFDM), Radio Resource Control (RRC), Time Division Duplex (TDD), Time Division Multiplexing (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), Transmission Reception Point (TRP), Multiple TRPs (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), Medium Access Control Control Element (MAC CE).

[0003] When the scheduling or triggering time offset is less than a threshold determined according to the UE capability report for scheduling PDSCH within and across carriers and for triggering aperiodic CSI-RS resources across carriers, the default TCI state or QCL assumption for the reception of downlink signals such as PDSCH and aperiodic CSI-RS resources is an important feature in NR Release 15 and Release 16. For example, for PDSCH transmission scheduled by DCI, the TCI state for the reception of PDSCH can be indicated by the 'Transmission Configuration Indication' field (i.e., TCI field) contained 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 a threshold determined according to the UE capability 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.

[0004] A single DCI-based multi-TRP DL transmission mode is introduced for cell-edge UEs in NR Release 16 to obtain high throughput and / or reliable transmission. PDSCH can be scheduled to be transmitted from two TRPs through two potential DL beams in FR2 in non-coherent joint transmission (NCJT) mode.

[0005] The higher layer parameter tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 indicates whether the 'transmission configuration indication' 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 scheduled PDSCH reception. The TCI field is 3 bits with eight possible values ​​(also called 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 PDCSH reception in 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.

[0006] In the following scenarios: (1) the scheduling offset (i.e., the time offset between the reception of the PDSCH scheduled by DCI and the PDCCH carrying the DCI) is less than the threshold for intra-carrier scheduled PDSCH reception, i.e., the PDCCH carrying the DCI and the scheduled PDSCH are transmitted in the same carrier; (2) an 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 presented in the scheduling DCI for all CORESETs (i.e., tci-PresentInDCI is set to 'enabled' for each of the CORESETs or tci-PresentInDCI-ForFormat1_2 is configured for all CORESETs), the default beam (i.e., default TCI state or default QCL assumption) for the reception of scheduled PDSCH transmissions 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.

[0007] However, tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is configured per CORESET, whereas the PDSCH TCI state is activated per BWP via a MAC CE activation command. Therefore, there may be a scenario where tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is not configured for all CORESETs configured for activation of BWP (i.e., some CORESETs are configured with tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 set to 'enabled', whereas some other CORESETs are not configured with tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2). In this condition, if at least one of the eight codepoints contained 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 reception of scheduled PDSCH is.

[0008] In addition, potential NCJT DL transmission should also be considered to determine the default TCI state for reception of cross-carrier scheduled aperiodic CSI-RS resources, i.e., the PDCCH carrying the triggered DCI and the triggered aperiodic CSI-RS resources are transmitted in different carriers.

[0009] The present disclosure aims at determining a default TCI state for reception of scheduled PDSCH and aperiodic CSI-RS resources for intra-carrier and cross-carrier scheduling in order to consider potential single-DCI based multi-TRP NCJT DL transmission. Summary of the invention

[0010] A method and apparatus for determining a default beam are disclosed.

[0011] In one embodiment, a method includes: receiving an activation command for activating BWP for a serving cell, wherein the activation command includes code points pointing to TCI states, 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 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 the TCI state for receiving the PDCCH or at least one TCI state pointed to by the code points pointing to two TCI states.

[0012] In one embodiment, the downlink signal is a PDSCH scheduled by a 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 that transmits the DCI that schedules the PDSCH, the default TCI state for reception of the scheduled PDSCH can be determined by the PDCCH QCL indication 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 activated BWP of the monitoring serving cell, 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 transmitting the DCI for the scheduled PDSCH, the default TCI state for the reception of the scheduled PDSCH may 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 transmitting the DCI for the scheduled PDSCH, the default TCI state for the reception of the scheduled PDSCH may be determined by the first TCI state pointed to by the lowest code point among the code points pointing to two different TCI states.

[0013] In another embodiment, the downlink signal is a PDSCH scheduled by a DCI carried in a PDCCH transmitted on a carrier different from the carrier of the PDSCH. Under this condition, regardless of whether the CORESET for transmitting the DCI that schedules the PDSCH is configured with tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2, 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. Alternatively, regardless of whether the CORESET for transmitting the DCI that schedules the PDSCH is configured with tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2, the default TCI state for 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.

[0014] In some embodiments, the downlink signal is an aperiodic CSI-RS triggered by DCI carried in a PDCCH transmitted on a carrier different from that 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 the higher layer parameter trs-Info and without the higher layer parameter repetition is less than a predetermined threshold, the default TCI state for 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.

[0015] In another embodiment, a remote unit includes: a receiver that receives an activation command for activating a BWP for a serving cell, wherein the activation command includes code points pointing to TCI states, and at least one code point points to two TCI states; and a processor that determines a default TCI state for receiving a corresponding downlink signal based on the TCI state for receiving the PDCCH or at least one TCI state pointed to by the code points pointing to the two TCI states when a scheduling offset between a downlink signal scheduled or triggered by a DCI and reception of a PDCCH carrying the DCI is less than a predetermined threshold.

[0016] In one embodiment, a method includes: transmitting an activation command for activating BWP for a serving cell, wherein 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 a 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 the TCI state for receiving the PDCCH or at least one TCI state pointed to by the code point pointing to two TCI states.

[0017] In yet another embodiment, a base station unit includes: a transmitter that transmits an activation command for activating a BWP for a serving cell, wherein 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 determines a default TCI state for receiving a corresponding downlink signal based on the TCI state for receiving the PDCCH or at least one TCI state pointed to by the code point pointing to the two TCI states when a scheduling offset between a downlink signal scheduled or triggered by a DCI and reception of a PDCCH carrying the DCI is less than a predetermined threshold. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] A more particular description of the embodiments briefly described above will be rendered by reference to specific embodiments that are illustrated in the accompanying drawings. Understanding that these drawings depict only some embodiments and are therefore not to be considered limiting of scope, the embodiments will be described and explained with additional uniqueness and detail through the use of the accompanying drawings, in which:

[0019] Figure 1 is a schematic flow chart illustrating an embodiment of a method;

[0020] Figure 2 is a schematic flow chart illustrating yet another embodiment of the method; and

[0021] Figure 3 is a schematic block diagram illustrating an apparatus according to one embodiment. DETAILED DESCRIPTION

[0022] As will be appreciated by those skilled in the art, certain aspects of the embodiments may be embodied as systems, devices, methods or program products. Therefore, the embodiments may take the form of a complete hardware embodiment, a complete software embodiment (including firmware, resident software, microcode, etc.) or an embodiment combining software and hardware aspects, which may be generally referred to herein as a "circuit", "module" or "system". In addition, the embodiments may take the form of a program product embodied in one or more computer-readable storage devices, which store 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-transmitting. The storage device may not embody a signal. In a certain embodiment, the storage device only uses a signal for accessing the code.

[0023] Some functional units described in this specification may be labeled as "modules" to more particularly emphasize 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 a programmable hardware device such as a field programmable gate array, programmable array logic, or a programmable logic device.

[0024] Modules may also be implemented in code and / or software for execution by various types of processors. An identification module of code may, for example, include one or more physical or logical blocks of executable code, which may, for example, be organized as objects, procedures, or functions. However, the executable files identifying the modules need not be physically located together, but may include different instructions stored in different locations, which, when logically joined together, comprise the module and implement the described purpose of the module.

[0025] In fact, the module of code can contain a single instruction or many instructions, and can even be distributed on several different code segments, in different programs and across several memory devices. Similarly, operating data can be identified and illustrated in this article in the module and can be embodied in any suitable form and organized in any suitable type of data structure. The operating data can be collected as a single data set, or can be distributed on different locations, including on different computer-readable storage devices. In the case where a module or parts of a module are implemented in software, the software part is stored on one or more computer-readable storage devices.

[0026] Any combination of one or more computer readable media 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 not necessarily, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

[0027] A non-exhaustive list of more specific examples of storage devices would 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 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.

[0028] The code for performing the operations of the embodiments may include any number of lines and may be written in any combination of one or more programming languages ​​including object-oriented programming languages ​​such as Python, Ruby, Java, Smalltalk, C++, and conventional procedural programming languages ​​such as the "C" programming language, and / or machine languages ​​such as assembly languages. The code may be executed entirely on the user's computer, partially on the user's computer, as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the last scenario, the remote computer may be connected to the user's computer via any type of network including a local area network (LAN) or a wide area network (WAN), or a connection to an external computer may be made (e.g., via the Internet using an Internet service provider).

[0029] References to "one embodiment," "an embodiment," or similar language throughout the specification mean that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment. Therefore, unless otherwise expressly specified, 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 expressly specified, the terms "include," "comprises," "has," and variations thereof mean "including but not limited to." Unless expressly specified, an enumerated list of items does not imply that any or all of the items are mutually exclusive. Unless otherwise expressly specified, the terms "one," "an," and "the" also mean "one or more."

[0030] In addition, the features, structures or characteristics of the various embodiments may be combined in any suitable manner. In the following description, many 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 using other methods, components, materials, etc. In other cases, known structures, materials or operations are not shown or described in detail to avoid confusing aspects of the embodiments.

[0031] Aspects of different embodiments are described below with reference to schematic flow charts and / or schematic block diagrams of methods, devices, systems, and program products according to embodiments. It will be understood that each frame of the schematic flow chart and / or schematic block diagram and the combination of frames in the schematic flow chart and / or schematic block diagram can be implemented by code. The code can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine, so that instructions executed by a processor of a computer or other programmable data processing device create a device for implementing the functions specified for one or more frames in the schematic flow chart and / or schematic block diagram.

[0032] The code may also be stored in a storage device that is capable of directing a computer, other programmable data processing apparatus, or other device to function in a specific manner so that the instructions stored in the storage device produce a product including instructions for implementing the functions specified in the blocks or some blocks of the schematic flowchart and / or schematic block diagram.

[0033] The code may 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 the computer, other programmable apparatus, or other device to produce a computer-implemented process, so that the code executed on the computer or other programmable apparatus provides a process for implementing the functions specified in a box or some boxes of the flowchart and / or block diagram.

[0034] The schematic flow charts and / or schematic block diagrams in the figures illustrate the architecture, functionality and operation of possible implementations of the apparatus, system, method and program product according to various embodiments. In this regard, each box in the schematic flow charts 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.

[0035] It should also be noted that in some alternative implementations, the functions annotated in the blocks may not occur in the order indicated in the various figures. For example, depending on the functionality involved, two blocks shown in succession may be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order. Other steps and methods that are equivalent in function, logic, or effect to one or more blocks or portions thereof of the illustrated figures may be envisioned.

[0036] Although various arrow types and line types may be used in flow charts 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 the logical flow of only the depicted embodiments. For example, an arrow may indicate a waiting or monitoring period of unspecified duration between the enumerated steps of the depicted embodiments. It will also be noted that each frame of the block diagram and / or flow chart, and the combination of the frames in the block diagram and / or flow chart can be implemented by a combination of a dedicated hardware-based system or dedicated hardware and code that performs the specified function or behavior.

[0037] Descriptions of elements in various figures may refer to elements of previous figures. The same reference numerals refer to the same elements in all figures, including alternative embodiments of the same elements.

[0038] The first embodiment is directed to determining a default TCI state for intra-carrier PDSCH scheduling in NCJT mode.

[0039] According to the first embodiment, the default TCI state for reception of the scheduled PDSCH is determined when the following three conditions are met:

[0040] (1) The DCI carried in the PDCCH schedules a PDSCH transmitted on the same carrier as the carrier of the PDCCH (i.e., intra-carrier scheduling of the PDSCH). The scheduled PDSCH may be sent 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'.

[0041] (2) PDCCH is transmitted in one of the CORESETs within the activated 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.

[0042] (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.

[0043] According to the first embodiment, the default TCI state for reception of the scheduled PDSCH is determined differently for a CORESET for which DCI for transmitting the scheduled PDSCH is not configured with tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 and for which tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 set to 'enabled' is configured. Note that a CORESET identifies a set of time-frequency resources for transmission of a PDCCH and each CORESET has a ControlResourceSetId.

[0044] In particular, for a CORESET that transmits DCI for a scheduled PDSCH for which tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is not configured, 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 port of the scheduled PDSCH of the serving cell is quasi-co-located (hereinafter, abbreviated as "QCLed") with the RS with respect to a QCL parameter, the QCL parameter being used for the PDCCH QCL indication of the CORESET associated with the monitored search space having the lowest ControlResourceSetId in the most recent timeslot in which one or more CORESETs within the activated BWP of the serving cell are monitored by the UE.

[0045] On the other hand, for a CORESET that transmits DCI for a scheduled PDSCH and for which tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is configured set to 'enabled', the default TCI state for 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 includes 'QCL-TypeD', the UE may assume that the DM-RS ports of the scheduled PDSCH of the serving cell are RS QCLed 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 a scheduled PDSCH contains 'QCL-TypeD', the UE shall derive 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 without having to determine the default beam.

[0046] The expression "regarding the QCL parameters associated with the TCI state and the RS QCLed" is further explained as follows:

[0047] The UE can be configured with a list of up to M TCI state configurations to decode the PDSCH from a detected PDCCH with DCI intended for the UE and a given serving cell, where M depends on the UE capabilities. The TCI state is configured by the following RRC signaling:

[0048]

[0049] Each TCI state contains parameters for configuring a quasi-co-location (QCL) relationship between one or two downlink reference signals (i.e., RS) and a DM-RS port of a PDSCH, a DM-RS port of a PDCCH, or a CSI-RS port of a CSI-RS resource. The quasi-co-location relationship is configured by a 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 type should be different, regardless of whether the reference is to the same downlink RS or different downlink RSs. The quasi-co-location type (i.e., QCL parameter) corresponding to each downlink RS is given by a higher layer parameter qcl-Type in QCL-Info and can take one of the following values:

[0050] 'QCL-TypeA': {Doppler shift, Doppler spread, average delay, delay spread}

[0051] 'QCL-TypeB': {Doppler shift, Doppler spread}

[0052] 'QCL-TypeC': {Doppler shift, average delay}

[0053] 'QCL-TypeD': {spatial Rx parameters}

[0054] 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, delay spread of the DM-RS port of the PDSCH are the same as those estimated by CSI-RS#1, and the UE can receive the PDSCH and the corresponding DM-RS port using the same spatial RX parameters as those used to receive CSI-RS#2. We can say that the UE can assume that the DM-RS port scheduled for PDSCH is quasi-co-located (i.e., QCLed) with CSI-RS#1 with respect to 'QCL-TypeA', and is quasi-co-located with CSI-RS#2 with respect to 'QCL-TypeD' (or in abbreviated form, "QCLed with respect to the QCL parameters associated with the indicated TCI state"). In other words, the QCL assumption of the DM-RS port scheduled for PDSCH (for reception of PDSCH) is determined according to the indicated TCI state.

[0055] The activation command (e.g., PDSCH TCI state activation / deactivation MAC CE) received by the UE is used to map up to eight different TCI states to the code points of the DCI field 'Transmission Configuration Indication' (i.e., TCI field) in 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.

[0056] An example of the first embodiment is described as follows:

[0057] Assume that the following PDSCH TCI state activation / deactivation MAC CE is received for the currently activated BWP of the serving cell, and at least one of the configured TCI states for the serving cell scheduled with PDSCH contains 'QCL-TypeD':

[0058] {

[0059] A TCI field with a codepoint value of '000' points to TCI state #1.

[0060] A TCI field with a codepoint value of '001' points to TCI state #2.

[0061] The TCI field with the code point value of '010' points to TCI state #5 and TCI state #8.

[0062] The TCI field with the code point value '011' points to TCI state #11.

[0063] The TCI field with a value of '100' code point points to TCI state #38.

[0064] The TCI field with the value '101' code point points to TCI state #52.

[0065] The TCI field with the value '110' points to TCI state #65 and TCI state #88.

[0066] The TCI field with the value '111' points to TCI state #110

[0067] }

[0068] Three CORESETs, eg, CORESET#1, CORESET#2, and CORESET#3, are configured for the activated BWP of the serving cell for the UE, wherein tci-PresentInDCI is not configured for CORESET#1, CORESET#2 and tci-PresentInDCI is set to 'enabled' for CORESET#3.

[0069] If the UE receives DCI with format 1_1 scheduling PDSCH transmission with a scheduling offset less than the threshold timeDurationForQCL, the default TCI state must be determined.

[0070] According to the first embodiment, if the UE receives DCI with format 1_1 transmitted from CORESET#1 that schedules PDSCH with a scheduling offset less than a threshold timeDurationForQCL, the UE may assume that the DM-RS port of the scheduled PDSCH is RS QCLed with respect to the QCL parameters associated with the TCI state indicated to the CORESET associated with the monitored search space with the lowest ControlResourceSetId in the most recent timeslot in which one or more CORESETs within the activated BWP of the serving cell are monitored by the UE. That is, the default TCI state is determined by the TCI state of the reception of the PDCCH associated with the monitored search space with the lowest ControlResourceSetId in the most recent timeslot in which one or more CORESETs within the activated BWP of the serving cell are monitored by the UE, regardless of the activation command.

[0071] On the other hand, according to the first embodiment, if the UE receives DCI transmitted from CORESET#3 that schedules PDSCH with a scheduling offset less than the threshold timeDurationForQCL, the UE can assume that the DM-RS port of the scheduled PDSCH is RS QCLed 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 pointing to two different TCI states.

[0072] The second embodiment relates to another option for determining the default TCI state for intra-carrier PDSCH scheduling in NCJT mode.

[0073] According to the second embodiment, a default TCI state for reception of a scheduled PDSCH is determined when the same three conditions as in the first embodiment are met.

[0074] The second embodiment is different from the first embodiment in that, for a CORESET that transmits DCI scheduling a PDSCH for which tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is not configured, a default TCI state for reception of the scheduled PDSCH is determined in a different manner.

[0075] According to the first embodiment, the UE is required to maintain 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. In order to reduce the number of beams maintained by the UE, according to the second embodiment, for the CORESET that transmits the DCI for the scheduled PDSCH without configuring tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 for this purpose, the default TCI state for 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 includes 'QCL-TypeD', the UE may assume that the DM-RS port of the scheduled PDSCH of the serving cell is RS QCLed with respect to the QCL parameters associated with one TCI state (preferably the first TCI state) pointed to by the lowest code point among the code points pointing to two different TCI states.

[0076] For a CORESET that transmits a DCI scheduling a PDSCH and for which tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is configured set to 'enabled', the default TCI state for reception of the scheduled PDSCH is determined in the same manner as in the first embodiment. That is, 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 RS QCLed 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. In general, according to the second embodiment, at most two different beams corresponding to the two default TCI states are maintained by the UE.

[0077] An example of the second embodiment is described as follows:

[0078] It is assumed that the currently activated BWP for the serving cell receives the same PDSCH TCI state activation / deactivation MAC CE as in the first embodiment.

[0079] Also similar to the first embodiment, three CORESETs, such as CORESET#1, CORESET#2 and CORESET#3, are configured for the activated BWP of the serving cell for the UE, wherein tci-PresentInDCI is not configured for CORESET#1 and CORESET#2 and tci-PresentInDCI is set to 'enabled' for CORESET#3.

[0080] According to a second embodiment, if the UE receives DCI with format 1_1 transmitted from CORESET #1 or CORESET #2 that schedules PDSCH with a scheduling offset less than a threshold timeDurationForQCL, the UE may assume that the DM-RS port of the scheduled PDSCH is RS QCLed 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 pointed to by the lowest code point pointing to two different TCI states.

[0081] According to the second embodiment, if the UE receives DCI with format 1_1 transmitted from CORESET#3 that schedules PDSCH with a scheduling offset less than the threshold timeDurationForQCL, the UE can assume that the DM-RS port of the scheduled PDSCH is RS QCLed with respect to the QCL parameters associated with TCI state #5 and TCI state #8, which is the same as the first embodiment.

[0082] The third embodiment relates to yet another option for determining a default TCI state for intra-carrier PDSCH scheduling in NCJT mode.

[0083] According to the third embodiment, a default TCI state for reception of a scheduled PDSCH is determined when the same three conditions as in the first embodiment are met.

[0084] The third embodiment is different from the first embodiment or the second embodiment in that, for both the CORESET of DCI for transmitting the scheduled PDSCH for which tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is not configured and the CORESET of DCI for transmitting the scheduled PDSCH for which tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is configured set to 'enabled', the default TCI state for reception of the scheduled PDSCH is determined in the same manner.

[0085] As described above, according to the first embodiment, the UE is required to maintain three different default beams for PDSCH reception, whereas according to the second embodiment, the UE is required to maintain two different default beams for PDSCH reception. According to the third embodiment, the UE will be required to maintain only one default beam for PDSCH reception. According to the third embodiment, for a CORESET that transmits DCI that schedules a PDSCH (regardless of whether tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is configured for the CORESET), the default TCI state for 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 includes 'QCL-TypeD', the UE may assume that the DM-RS port of the scheduled PDSCH of the serving cell is RS QCLed with respect to the QCL parameters associated with one TCI state (preferably the first TCI state) pointed to by the lowest code point among the code points pointing to two different TCI states.

[0086] An example of the third embodiment is described as follows:

[0087] It is assumed that the currently activated BWP for the serving cell receives the same PDSCH TCI state activation / deactivation MAC CE as in the first embodiment.

[0088] Also similar to the first embodiment, three CORESETs, such as CORESET#1, CORESET#2 and CORESET#3, are configured for the activated BWP of the serving cell for the UE, wherein tci-PresentInDCI is not configured for CORESET#1 and CORESET#2 and tci-PresentInDCI is set to 'enabled' for CORESET#3.

[0089] According to a third embodiment, if the UE receives DCI with format 1_1 transmitted from CORESET#1 or CORESET#2 or CORESET#3 that schedules PDSCH with a scheduling offset less than a threshold timeDurationForQCL, the UE may assume that the DM-RS port of the scheduled PDSCH is RS QCLed 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 pointed to by the lowest code point pointing to two different TCI states.

[0090] The fourth embodiment is directed to determining a default TCI state for cross-carrier scheduling in NCJT mode.

[0091] According to the fourth embodiment, the default TCI state for reception of the scheduled PDSCH is determined when the following three conditions are met:

[0092] (1) The DCI carried in the PDCCH schedules PDSCH transmission on a carrier different from the carrier of the PDCCH (i.e., cross-carrier scheduled PDSCH). In other words, the PDCCH carrying the scheduled DCI is received on one component carrier, while the PDSCH scheduled by the DCI is received on another component carrier. The time offset between the scheduled PDSCH and the reception of 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 ) is smaller than the subcarrier space (μ) of the carrier transmitting the PDSCH PDSCH ), namely μ PDCCH <μ PDSCH , then an additional timing delay d is added to timeDurationForQCL as defined in NR Release 15.

[0093] (2) PDCCH is transmitted in one of the CORESETs within the activated 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.

[0094] (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.

[0095] According to the fourth embodiment, for a CORESET that transmits DCI that schedules a PDSCH (regardless of whether tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is configured for the CORESET), the default TCI state for 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 includes 'QCL-TypeD', the UE may assume that the DM-RS port of the scheduled PDSCH of the serving cell is RS QCLed 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 a scheduled PDSCH contains 'QCL-TypeD', the UE shall derive 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 without having to determine the default beam.

[0096] An example of the fourth embodiment is described as follows:

[0097] 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 currently activated BWP of CC#2, and at least one of the configured TCI states of the serving cell for the scheduled PDSCH contains 'QCL-TypeD':

[0098] {

[0099] A TCI field with a codepoint value of '000' points to TCI state #1.

[0100] A TCI field with a codepoint value of '001' points to TCI state #2.

[0101] The TCI field with the code point value of '010' points to TCI state #5 and TCI state #8.

[0102] The TCI field with the code point value '011' points to TCI state #11.

[0103] The TCI field with a value of '100' code point points to TCI state #38.

[0104] The TCI field with the value '101' code point points to TCI state #52.

[0105] The TCI field with the value '110' points to TCI state #65 and TCI state #88.

[0106] The TCI field with the value '111' points to TCI state #110

[0107] }

[0108] 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.

[0109] The fifth embodiment relates to another option for determining a default TCI state for cross-carrier PDSCH scheduling in NCJT mode.

[0110] According to the fifth embodiment, a default TCI state for reception of a scheduled PDSCH is determined when the same three conditions as in the fourth embodiment are satisfied.

[0111] Different UE capabilities may be reported by the UE 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) and cannot support NCJT in CC#1 (on which the PDCCH carrying the scheduling DCI is transmitted), if the scheduling offset is less than a threshold, the UE can receive the PDSCH through a single default TCI state.

[0112] When the UE receives DCI carried in the PDCCH on a cell without NCJT capability to schedule PDSCH on another cell and the scheduling offset is less than a threshold, according to the fifth embodiment, the default TCI state for 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 port of the scheduled PDSCH of the serving cell is RS QCLed with respect to the QCL parameters associated with one TCI state (preferably the first TCI state) pointed to by the lowest code point among the code points pointing to two different TCI states.

[0113] An example of the fifth embodiment is described as follows:

[0114] The UE receives DCI carried in the PDCCH transmitted on CC#1 that schedules the PDSCH transmitted on CC#2. It is assumed that the current active BWP for CC#2 receives the same PDSCH TCI state activation / deactivation MAC CE as in the fourth embodiment.

[0115] According to the fifth embodiment, the UE may assume that the DM-RS port for the scheduled PDSCH is RS QCLed 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 pointed to by the lowest code point pointing to two different TCI states.

[0116] The sixth embodiment is directed to determining a default TCI state for cross-carrier aperiodic CSI-RS resource triggering.

[0117] Unlike PDSCH transmission in 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.

[0118] According to the sixth embodiment, the default TCI state for reception of the triggered CSI-RS is determined when the following three conditions are met:

[0119] (1) The DCI carried in the PDCCH triggers the transmission of aperiodic CSI-RS 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 triggered DCI is received on one component carrier, while the aperiodic CSI-RS resources triggered by the DCI are received on another component carrier. The subcarrier space (μ PDCCH ) is smaller than the subcarrier space of the carrier transmitting the CSI-RS ( μCSIRS ), namely 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 UE reported threshold beamSwitchTiming + d in units of PDCCH symbols. The reported value of beamSwitchTiming indicates the duration for the UE to perform beam switching and is one of the values ​​of {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):

[0120] Table 5.2.1.5.1a-1: Additional beam switching timing delay d

[0121] <![CDATA[μ PDCCH ]]> d[PDCCH symbol] 0 8 1 8 2 14

[0122] (2) There are no other DL signals 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 is to be received.

[0123] (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.

[0124] By the way, condition (2) is included to indicate that only condition (2) is satisfied, it is necessary to determine the default TCI state. If there is any other DL signal with the 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 non-periodic CSI-RS. The other DL signal refers to a PDSCH scheduled at an offset greater than or equal to the threshold timeDurationForQCL as defined in [13, TS38.306], a PDSCH scheduled at an offset greater than or equal to the threshold timeDurationForQCL as defined in [13, TS38.306], a threshold beamSwitchTiming+d*μ greater than or equal to the UE report in the CSI-RS symbol when the reported value is one of {14, 28, 48}. PDCCH / μ PDSCH Aperiodic CSI-RS scheduled with an offset of 48+d, 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}, Periodic CSI-RS, Semi-persistent CSI-RS. If at least one CORESET is configured for the BWP in which the aperiodic CSI-RS is to be received, then when the aperiodic CSI-RS is received, the UE applies the QCL assumption for the CORESET associated with the monitored search space with the lowest ControlResourceSetId in the most recent slot of one or more CORESETs within the activated BWP in which the serving cell is monitored.

[0125] According to the sixth embodiment, the default TCI state for reception of the triggered CSI-RS 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 triggered CSI-RS includes 'QCL-TypeD', the UE may assume that the CSI-RS resource is QCLed with respect to the QCL parameters associated with one TCI state (preferably the first TCI state) pointed to by the lowest code point among the code points pointing to two different TCI states.

[0126] An example of the sixth embodiment is described as follows:

[0127] The UE receives DCI carried in the PDCCH transmitted on CC#1 that triggers aperiodic CSI-RS resources transmitted on CC#2. The following PDSCH TCI state activation / deactivation MAC CE is received for the currently activated BWP for CC#2, and at least one of the configured TCI states of the serving cell for the triggered CSI-RS contains 'QCL-TypeD':

[0128] {

[0129] A TCI field with a codepoint value of '000' points to TCI state #1.

[0130] A TCI field with a codepoint value of '001' points to TCI state #2.

[0131] The TCI field with the code point value of '010' points to TCI state #5 and TCI state #8.

[0132] The TCI field with the code point value '011' points to TCI state #11.

[0133] The TCI field with a value of '100' code point points to TCI state #38.

[0134] The TCI field with the value '101' code point points to TCI state #52.

[0135] The TCI field with the value '110' points to TCI state #65 and TCI state #88.

[0136] The TCI field with the value '111' points to TCI state #110

[0137] }

[0138] According to a sixth embodiment, when the trigger offset between the last symbol of the PDCCH carrying the triggered DCI and the first symbol of the non-periodic CSI-RS resource configured without the higher layer parameter trs-Info and without the higher layer parameter repetition is less than the UE reported threshold beamSwitchTiming+d in units of PDCCH symbols, the UE may assume that the triggered CSI-RS is QCLed 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.

[0139] Figure 1 1 is a schematic flow chart illustrating an embodiment of a method 100 according to the present application. In some embodiments, the method 100 is performed by a device such as a base station unit. In some embodiments, the method 100 can be performed by a processor that executes program code, such as a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, an FPGA, etc.

[0140] Method 100 may include 102 receiving an activation command for activating a BWP for a serving cell, wherein 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 a DCI and the reception of a PDCCH carrying the DCI is less than a predetermined threshold, 104 determining a default TCI state for receiving a 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.

[0141] Figure 2 2 is a schematic flow chart illustrating an embodiment of a method 200 according to the present application. In some embodiments, the method 200 is performed by a device such as a base station unit. In some embodiments, the method 200 can be performed by a processor that executes program code, such as a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, an FPGA, etc.

[0142] Method 200 may include 202 transmitting an activation command for activating a BWP for a serving cell, wherein 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 a DCI and the reception of a PDCCH carrying the DCI is less than a predetermined threshold, 204 determining a default TCI state for receiving a 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.

[0143] Figure 3 is a schematic block diagram illustrating an apparatus according to one embodiment.

[0144] refer to Figure 3 , UE (ie, remote unit) includes a processor, a memory and a transceiver. The processor is implemented in Figure 1 The functions, processes and / or methods proposed in the gNB (i.e., base station unit) include a processor, a memory and a transceiver. The processor implements Figure 2 The functions, processes and / or methods proposed in the present invention are described in detail. The layers of the radio interface protocol can be implemented by a 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 can be implemented as a transmitter for transmitting radio signals and a receiver for receiving radio signals.

[0145] The memory may be located inside or outside the processor and connected to the processor through various well-known means.

[0146] In the above-described 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 as an option. Each component or feature can be implemented as not being associated with other components or features. In addition, the embodiments can be configured by associating some components and / or features. The order of the operations described in the embodiments can be changed. Some components or features of any embodiment can be included in another embodiment or replaced with components and features corresponding to another embodiment. It is obvious that claims that are not explicitly cited in the claims are combined to form embodiments or are included in new claims.

[0147] The embodiments may be implemented by hardware, firmware, software or a combination thereof. In the case of being implemented by hardware, according to the hardware implementation, the exemplary embodiments 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, microcontrollers, microprocessors, etc.

[0148] Embodiments may be practiced in other specific forms. The described embodiments will be considered in all respects to be illustrative only and not restrictive. The scope of the present invention is therefore indicated by the appended claims rather than by the preceding description. All changes falling within the equivalent meaning and scope of the claims should be included within their scope.

Claims

1. A method performed at a remote unit, comprising: receiving an activation command for an activated bandwidth part (BWP) of a serving cell, wherein the activation command comprises 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 the scheduling offset between the reception of a physical downlink control channel PDCCH carrying downlink control information DCI and the 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, at least one of the one or more default TCI states for the reception of the scheduled PDSCH is determined based on at least one TCI state pointed to by code points 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 that transmits the DCI that schedules 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 tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is not configured for the CORESET that transmits the DCI that schedules the PDSCH, the default TCI state for reception of the scheduled PDSCH is determined by the 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 that transmits the DCI that schedules the PDSCH, the default TCI state for reception of the scheduled PDSCH is determined by the first TCI state pointed to by the lowest code point among the code points pointing to two different TCI states.

5. A remote unit comprising: a receiver, the receiver receiving an activation command for an activated bandwidth part BWP for a serving cell, wherein the activation command comprises 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, 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, the processor determines at least one of one or more default TCI states for reception of the scheduled PDSCH based on at least one TCI state pointed to by code points pointing to two TCI states.

6. The remote unit of claim 5, wherein: When tci-PresentInDCI is set to "enabled" or tci-PresentInDCI-ForFormat1_2 is configured for the CORESET that transmits the DCI that schedules 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.

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

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

Images