Default beam determination in cross-carrier scheduling

Abstract

A method and apparatus for determining a default beam are disclosed. A method includes: receiving a control signal that schedules or triggers a downlink signal, wherein the control signal is received on a first carrier, the downlink signal is received on a second carrier, the first carrier being different from the second carrier; and if the scheduling or triggering offset is less than a threshold, determining a default TCI state for reception of the downlink signal according to a higher layer parameter CORESETPoolIndex.

Description

Technical Field

[0001] The subject matter disclosed herein relates generally to wireless communications, and more specifically to methods and apparatus for utilizing cross-carrier scheduling to determine 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 referenced within 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 ), 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 Indicator (TCI), Control Resource Set (CORESET), Reference Signal (RS), Component Carrier (CC), Bandwidth Part (BWP), Medium Access Control (MAC), Control Element (CE), Demodulation Reference Signal (DM-RS).

[0003] The default TCI state or QCL assumption for the reception of downlink signals such as PDSCH and non-periodic CSI-RS resources when the scheduling or triggering time offset is less than a threshold determined according to the UE capabilities 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, the default TCI state has to be determined. In other words, the capabilities reported by the UE (e.g., timeDurationForQCL) indicate the duration required for the UE to determine the QCL.

[0004] Multi-TRP DL transmission based on multi-DCI has been specified in NR Release 16. Multiple TRPs are able to schedule multiple PDSCH transmissions in the same carrier for a UE in one time slot. A TRP-specific TCI state can be activated for the UE to support multi-TRP DL transmission based on multi-DCI. A higher layer parameter CORESETPoolIndex can be configured for the CORESET to identify the TRP. Each activated TCI state is associated with a CORESETPoolIndex value. Cross-carrier DL scheduling is supported in NR Release 16, and the default QCL assumption is determined for DL ​​reception when the scheduling offset is less than a threshold. The default QCL assumption for a single TRP is determined by the activated TCI state with the lowest ID applicable to the PDSCH. Because different activated TCI states associated with different CORESETPoolIndex values ​​are used for different TRPs, an incorrect QCL assumption can be determined according to NR Release 15. The higher layer parameter CORESETPoolIndex should be considered when determining the default TCI state for cross-carrier PDSCH and aperiodic CSI-RS reception.

[0005] Considering the potential multi-DCI based multi-TRP DL transmission, the present invention aims at the default TCI state for cross-carrier PDSCH and aperiodic CSI-RS reception. Summary of the invention

[0006] A method and apparatus for determining a default beam are disclosed.

[0007] In one embodiment, a method includes: receiving a control signal that schedules or triggers a downlink signal, wherein the control signal is received on a first carrier, the downlink signal is received on a second carrier, and the first carrier is different from the second carrier; and if the scheduling or triggering offset is less than a threshold, determining a default TCI state for reception of the downlink signal based on a higher layer parameter CORESETPoolIndex.

[0008] In one embodiment, the downlink signal is a PDSCH scheduled by a DCI. When a higher layer parameter CORESETPoolIndex with different values ​​is configured for both a CORESET configured on a first carrier and a CORESET configured on a second carrier, it can be assumed that the DM-RS port of the scheduled PDSCH is quasi-co-located with the RS with respect to the QCL parameters associated with the activated TCI state with the lowest ID of the PDSCH associated with the same CORESETPoolIndex as the DCI that schedules the PDSCH in the active BWP applicable to the second carrier; when a higher layer parameter CORESETPoolIndex with different values ​​is configured for the CORESET configured on the first carrier and the higher layer parameter CORESETPoolIndex is not configured for any CORESET configured on the second carrier When the DM-RS ports of the scheduled PDSCH are assumed to be quasi-co-located with the RS with respect to the QCL parameters associated with the activated TCI state with the lowest ID of the PDSCH in the active BWP applicable to the second carrier; and when the higher layer parameter CORESETPoolIndex is not configured for any CORESET configured on the first carrier and the higher layer parameter CORESETPoolIndex with a different value is configured for the CORESET configured on the second carrier, the DM-RS ports of the scheduled PDSCH are assumed to be quasi-co-located with the RS with respect to the QCL parameters associated with the activated TCI state with the lowest ID of the PDSCH associated with CORESETPoonIndex=0 in the active BWP applicable to the second carrier.

[0009] In another embodiment, the downlink signal is an aperiodic CSI-RS triggered by a DCI. When there are two scheduled PDSCHs associated with different CORESETPoolIndex values ​​with an indicated TCI state in the same symbol as the triggered aperiodic CSI-RS, (1) when a higher layer parameter CORESETPoolIndex with different values ​​is configured for a CORESET configured on an active BWP of a first carrier, when an aperiodic CSI-RS is received, a QCL assumption of the scheduled PDSCH associated with the same CORESETPoolIndex value as the DCI that triggered the aperiodic CSI-RS may be applied; (2) when a higher layer parameter CORESETPoolIndex is not configured for any CORESET configured on an active BWP of the first carrier, when an aperiodic CSI-RS is received, a QCL assumption of the scheduled PDSCH associated with CORESETPoolIndex=0 may be applied.When there is no other DL signal with an indicated TCI state in the same symbol as the triggered aperiodic CSI-RS, (1) when a higher layer parameter CORESETPoolIndex with different values ​​is configured for both the CORESET configured on the first carrier and the CORESET configured on the second carrier, when the aperiodic CSI-RS is received, the QCL assumption for the CORESET associated with the monitored search space with the lowest ControlResourceSetId among the CORESETs configured with the same CORESETPoolIndex value as the DCI that triggered the aperiodic CSI-RS may be applied in the latest time slot in which one or more CORESETs within the active BWP of the monitoring serving cell are monitored; (2) when a higher layer parameter CORESETPoolIndex with different values ​​is configured for the CORESET configured on the first carrier and the higher layer parameter CORESETPoolIndex is not configured for any CORESET configured on the second carrier SETPoolIndex, when a non-periodic CSI-RS is received, the QCL assumption for the CORESET associated with the monitored search space with the lowest ControlResourceSetId can be applied in the latest time slot in which one or more CORESETs within the active BWP of the monitoring service cell are monitored; (3) when the higher layer parameter CORESETPoolIndex is not configured for any CORESET configured on the first carrier and a higher layer parameter CORESETPoolIndex with a different value is configured for the CORESET configured on the second carrier, when a non-periodic CSI-RS is received, the QCL assumption for the CORESET associated with the monitored search space with the lowest ControlResourceSetId among the CORESETs configured with CORESETPoolIndex=0 can be applied in the latest time slot in which one or more CORESETs within the active BWP of the monitoring service cell are monitored.

[0010] In some embodiments, when there is no other DL signal with an indicated TCI state in the same symbol as the triggered aperiodic CSI-RS, (1) when a higher layer parameter CORESETPoolIndex with a different value is configured for a CORESET configured on an active BWP of a first carrier and each of the activated TCI states for a PDSCH on an active BWP of a second carrier is associated with a CORESETPoolIndex value, when an aperiodic CSI-RS is received, the QCL assumption of the activated TCI state with the lowest ID associated with the same CORESETPoolIndex value as the DCI that triggered the aperiodic CSI-RS applicable to the PDSCH in the active BWP of the second carrier may be applied; (2) when a higher layer parameter CORESETPoolIndex is not configured for any CORESET configured on the active BWP of the first carrier, the QCL assumption of the activated TCI state with the lowest ID associated with the same CORESETPoolIndex value as the DCI that triggered the aperiodic CSI-RS may be applied. dex and each of the activated TCI states for the PDSCH on the active BWP of the second carrier is associated with a CORESETPoolIndex value, when a non-periodic CSI-RS is received, the QCL assumption of the activated TCI state with the lowest ID associated with CORESETPoolIndex=0 applicable to the PDSCH in the active BWP of the second carrier can be applied; (3) when a higher layer parameter CORESETPoolIndex with a different value is configured for the CORESET configured on the active BWP of the first carrier and the activated TCI state for the PDSCH on the active BWP of the second carrier is not associated with any CORESETPoolIndex value, when a non-periodic CSI-RS is received, the QCL assumption of the activated TCI state with the lowest ID applicable to the PDSCH in the active BWP of the second carrier can be applied.

[0011] In another embodiment, a remote unit includes: a receiver that receives a control signal that schedules or triggers a downlink signal, wherein the control signal is received on a first carrier and the downlink signal is received on a second carrier, and the first carrier is different from the second carrier; and a processor that determines a default TCI state for reception of the downlink signal based on a higher layer parameter CORESETPoolIndex if the scheduling or triggering offset is less than a threshold.

[0012] In one embodiment, a method includes: transmitting a control signal for scheduling or triggering a downlink signal, wherein the control signal is transmitted on a first carrier and the downlink signal is transmitted on a second carrier, the first carrier being different from the second carrier; and if the scheduling or triggering offset is less than a threshold, determining a default TCI state for transmission of the downlink signal based on a higher layer parameter CORESETPoolIndex.

[0013] In another embodiment, a base station unit includes a transmitter that transmits a control signal that schedules or triggers a downlink signal, wherein the control signal is transmitted on a first carrier and the downlink signal is transmitted on a second carrier, and the first carrier is different from the second carrier; and a processor that determines a default TCI state for transmission of the downlink signal based on a higher layer parameter CORESETPoolIndex if the scheduling or triggering offset is less than a threshold. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] A more particular description of the embodiments briefly described above will be presented by reference to specific embodiments 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:

[0015] Figure 1 is a schematic flow chart illustrating an embodiment of a method;

[0016] Figure 2 is a schematic flow chart illustrating yet another embodiment of the method; and

[0017] Figure 3 is a schematic block diagram illustrating an apparatus according to one embodiment. DETAILED DESCRIPTION

[0018] 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. Thus, the embodiments may take the form of a complete hardware embodiment, a complete software embodiment (including firmware, resident software, microcode, etc.), or a combination of software and hardware aspects, which may generally be 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 that 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 employs only a signal for accessing the code.

[0019] 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, a programmable logic device, etc.

[0020] 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 achieve the stated purpose of the module.

[0021] 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 the module or parts of the module are implemented in software, the software part is stored on one or more computer-readable storage devices.

[0022] 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.

[0023] 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 conjunction with an instruction execution system, apparatus, or device.

[0024] 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 through any type of network including a local area network (LAN) or a wide area network (WAN), or a connection may be made to an external computer (e.g., over the Internet using an Internet service provider).

[0025] References to "one embodiment", "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, refer to the same embodiment, but rather mean "one or more but not all embodiments". Unless otherwise expressly specified, the terms "include", "comprising", "having" and their variations mean "including but not limited to". Unless otherwise 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".

[0026] 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 any ambiguity in various aspects of the embodiments.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] Although various arrow types and line types can 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 can be used to indicate the logical flow of only the depicted embodiments. For example, an arrow can indicate a waiting or monitoring period of unspecified duration between the enumeration 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 each frame 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 a specified function or action.

[0033] The description of an element in each figure may refer to an element of a previous figure. The same reference numerals refer to the same elements in all figures, including alternative embodiments of the same elements.

[0034] The first embodiment involves determining a default TCI state for cross-carrier PDSCH scheduling.

[0035] According to the first embodiment, the default TCI state for reception of the scheduled PDSCH is determined when the following three conditions are met:

[0036] (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 (e.g., CC#1), while the PDSCH scheduled by the DCI is received on another component carrier (e.g., CC#2).

[0037] (2) The time offset between the reception of the DL DCI and the scheduled PDSCH is less than the threshold timeDurationForQCL. The threshold 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 ), that is, μ PDCCH <μ PDSCH , then add additional time delay to timeDurationForQCL where d is defined as in NR Release 15.

[0038] (3) Regardless of whether tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is configured for the CORESET transmitting the PDCCH carrying DCI. That is, when tci-PresentInDCI is set to "enabled" or tci-PresentInDCI-ForFormat1_2 is configured for the CORESET transmitting the PDCCH carrying DCI, or when tci-PresentInDCI or tci-PresentInDCI-ForFormat1_2 is not configured for the CORESET transmitting the PDCCH carrying DCI.

[0039] According to the first embodiment, a default TCI state for reception of a scheduled PDSCH is determined in three different cases.

[0040] Case 1-1: A higher layer parameter CORESETPoolIndex with different values ​​is configured for the CORESET configured on two carriers. That is, a higher layer parameter CORESETPoolIndex with different values ​​is configured for the CORESET configured on the carrier on which the PDCCH carrying the scheduled DCI is received (i.e., on CC#1), and a higher layer parameter CORESETPoolIndex with different values ​​is configured for the CORESET configured on the carrier on which the PDSCH scheduled by the DCI is received (i.e., on CC#2). In case 1-1, the UE may assume that the DM-RS port of the scheduled PDSCH is quasi-co-located (hereinafter, may be abbreviated as "QCLed") with respect to the QCL parameters associated with the activated TCI state with the lowest ID of the PDSCH associated with the same CORESETPoolIndex value as the CORESETPoolIndex value of the CORESET for the PDCCH carrying the DCI that schedules the PDSCH in the active BWP applicable to the scheduled carrier (i.e., CC#2) as the DCI that schedules the PDSCH (which may be abbreviated as "same CORESETPoolIndex as the DCI that schedules the PDSCH").

[0041] Case 1-2: The higher layer parameter CORESETPoolIndex is configured with a different value for the CORESET configured on the carrier on which the PDCCH carrying the scheduled DCI is received (i.e., on CC#1), and the higher layer parameter CORESETPoolIndex is not configured for any CORESET configured on the carrier on which the PDSCH scheduled by the DCI is received (i.e., on CC#2). In case 1-2, the UE may assume that the DM-RS ports of the scheduled PDSCH are RS QCLed with respect to the QCL parameters associated with the activated TCI state with the lowest ID for the PDSCH in the active BWP applicable to the scheduled carrier (i.e., CC#2).

[0042] Case 1-3: The higher layer parameter CORESETPoolIndex is not configured for any CORESET configured on the carrier on which the PDCCH carrying the scheduled DCI is received (i.e., on CC#1), and the higher layer parameter CORESETPoolIndex is configured with a different value for the CORESET configured on the carrier on which the PDSCH scheduled by the DCI is received (i.e., on CC#2). In case 1-3, the UE may assume that the DM-RS ports of the scheduled PDSCH are RS QCLed with respect to the QCL parameters associated with the activated TCI state with the lowest ID associated with the PDSCH associated with the lowest CORESETPoolIndex (i.e., CORESETPoolIndex=0) in the active BWP applicable to the scheduled carrier (i.e., CC#2).

[0043] The expression "Regarding the QCL parameters associated with the TCI state and RS QCLed" is further explained as follows:

[0044] 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 via the following RRC signaling:

[0045]

[0046] 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 same downlink RS or different downlink RSs are referenced. 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:

[0047] 'QCL-TypeA': {Doppler shift, Doppler spread, average delay, delay spread}

[0048] 'QCL-TypeB': {Doppler shift, Doppler spread}

[0049] 'QCL-TypeC': {Doppler shift, average delay}

[0050] 'QCL-TypeD': {spatial Rx parameters}

[0051] 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 of the scheduled 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 activated TCI state"). In other words, the QCL of the DM-RS port of the scheduled PDSCH (for reception of the PDSCH) is assumed to be determined according to the activated TCI state.

[0052] An example of the first embodiment is described as follows:

[0053] Five CORESETs, e.g., CORESET#1, CORESET#2, CORESET#3, CORESET#4, and CORESET#5, are configured for the active BWP of the UE's serving cell CC#2 (i.e., the carrier on which the PDSCH scheduled by DCI is received), and a higher layer parameter CORESETPoolIndex=0 is configured for CORESET#1, CORESET#2, and CORESET#3, and CORESETPoolIndex=1 is configured for CORESET#4 and CORESET#5. CORESETPoolIndex=0 for the active BWP of serving cell CC#2 activates {TCI-state #2, TCI-state #5, TCI-state #8, TCI-state #12, TCI-state #18, TCI-state #23, TCI-state #28, TCI-state #32} and CORESETPoolIndex=1 for the active BWP of serving cell CC#2 activates {TCI-state #42, TCI-state #45, TCI-state #48, TCI-state #52, TCI-state #58, TCI-activation-state #63, TCI-state #68, TCI-state #72}.

[0054] If a UE receives DCI carried by a PDCCH from a CORESET configured with CORESETPoolIndex=1 on CC#1 (i.e., the carrier on which the PDCCH carrying the DCI is received) that schedules PDSCH transmission on CC#2, when the scheduling offset is less than a threshold, the UE may assume that the DM-RS ports of the scheduled PDSCH are RS QCLed with respect to the QCL parameters associated with the activated TCI state with the lowest ID (i.e., TCI-state #42) for the PDSCH associated with CORESETPoonIndex=1 in the active BWP applicable to CC#2. This is an example of case 1-1.

[0055] If CORESETPoolIndex is not configured for any CORESET configured on the active BWP of CC#1 and the UE receives DCI carried by PDCCH on CC#1 that schedules PDSCH transmission on CC#2, when the scheduling offset is less than the threshold, the UE may assume that the DM-RS ports of the scheduled PDSCH are RS QCLed with respect to the QCL parameters associated with the activated TCI state with the lowest ID (i.e., TCI-state #2) for the PDSCH associated with CORESETPoonIndex=0 in the active BWP applicable to CC#2. This is an example of case 1-3.

[0056] The second to fifth embodiments relate to determining a default TCI state for triggering aperiodic CSI-RS across carriers.

[0057] According to the second to fifth embodiments, the default TCI state for reception of a triggered aperiodic CSI-RS is determined when the following two conditions are met:

[0058] (1) The DCI carried in the PDCCH triggers 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 (e.g., CC#1), while the aperiodic CSI-RS resources triggered by the DCI are received on another component carrier (e.g., CC#2).

[0059] (2) Subcarrier space of the carrier transmitting PDCCH (μ PDCCH ) is smaller than the subcarrier space (μ) of the carrier transmitting the CSI-RS CSIRS ), that is, μ PDCCH <μ CSIRS The trigger offset between the last symbol of the PDCCH carrying the triggered 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 reported by the UE in units of CSI-RS 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):

[0060] Table 5.2.1.5.1a-1: Additional beam switching timing delay d

[0061] <![CDATA[μ PDCCH ]]> d[PDCCH symbol] 0 8 1 8 2 14

[0062] In a second embodiment, there is one scheduled PDSCH with an indicated TCI state in the same symbol as the CSI-RS. In addition, the PDSCH is scheduled with a time offset greater than or equal to a threshold timeDurationForQCL.

[0063] According to the second embodiment, when receiving the triggered aperiodic CSI-RS, the UE may apply the QCL assumption of the scheduled PDSCH (ie, the TCI state of the scheduled PDSCH).

[0064] In the third embodiment, there are two PDSCHs scheduled by DCI transmitted from different CORESETs configured with different CORESETPoolIndex values ​​with indicated TCI states in the same symbol as CSI-RS. In addition, each of the two PDSCHs is scheduled with a time offset greater than or equal to a threshold timeDurationForQCL.

[0065] According to the third embodiment, a default TCI state for reception of a triggered aperiodic CSI-RS is determined in two different cases.

[0066] Case 3-1: A higher layer parameter CORESETPoolIndex with a different value is configured for the CORESET configured on the active BWP of CC#1 (the carrier on which the PDCCH carrying the DCI triggering the aperiodic CSI-RS is received). In case 3-1, the UE may apply the QCL assumption of the PDSCH scheduled by the DCI (i.e., the TCI state indicated by it) transmitted from the CORESET configured with the same CORESETPoolIndex value as the CORESETPoolIndex value of the CORESET carrying the DDCCH triggering the aperiodic CSI-RS (which may be abbreviated as "the same CORESETPoolIndex value as the DCI triggering the aperiodic CSI-RS") for the reception of the triggered aperiodic CSI-RS.

[0067] Case 3-2: The higher layer parameter CORESETPoolIndex is not configured for any CORESET configured on the active BWP of CC#1. The UE may apply the QCL assumption of the PDSCH scheduled by DCI (i.e., the TCI state indicated for it) transmitted from the CORESET configured with the lowest CORESETPoolIndex (i.e., CORESETPoolIndex=0) for the reception of the triggered aperiodic CSI-RS.

[0068] An example of situation 3-1 is as follows:

[0069] The UE receives DCI carried in the PDCCH from a CORESET configured with CORESETPoolIndex=1 on CC#1 that triggers aperiodic CSI-RS transmission on CC#2. There are two PDSCH transmissions (e.g., PDSCH transmission #1 and PDSCH transmission #2). PDSCH transmission #1 is scheduled by DCI #1 from a CORESET configured with CORESETPoolIndex=0, and PDSCH transmission #2 is scheduled by DCI #2 from a CORESET configured with CORESETPoolIndex=1. If the triggering offset of the aperiodic CSI-RS is less than the threshold, the UE applies the TCI state indicated for PDSCH transmission #2 as the default TCI state for reception of the triggered aperiodic CSI-RS.

[0070] In the fourth embodiment, there is no other DL signal with an indicated TCI state in the same symbol as the CSI-RS, and at least one CORESET is configured for a BWP to transmit an aperiodic CSI-RS.

[0071] Other DL signals refer to any of the following: PDSCH scheduled with a scheduling offset greater than or equal to the threshold timeDurationForQCL as defined in [13, TS 38.306]; PDSCH scheduled with a scheduling offset greater than or equal to the threshold timeDurationForQCL in a CSI-RS symbol when the reporting value is one of {14, 28, 48} aperiodic CSI-RS triggered with a trigger offset of 48+d; aperiodic CSI-RS triggered with a trigger offset greater than or equal to 48+d when the reported value of beamSwitchTiming is one of {224,336}; periodic CSI-RS; and semi-persistent CSI-RS.

[0072] According to the fourth embodiment, a default TCI state for reception of a triggered aperiodic CSI-RS is determined in three different cases.

[0073] Case 4-1: A higher layer parameter CORESETPoolIndex with different values ​​is configured for the CORESET configured on two carriers. That is, a higher layer parameter CORESETPoolIndex with different values ​​is configured for the CORESET configured on the carrier on which the PDCCH carrying the triggering DCI is received (i.e., on CC#1), and a higher layer parameter CORESETPoolIndex with different values ​​is configured for the CORESET configured on the carrier on which the aperiodic CSI-RS triggered by the DCI is received (i.e., on CC#2). In case 4-1, when aperiodic CSI-RS is received, the UE may apply, in the latest timeslot of one or more CORESETs within the active BWP of the monitored serving cell, the QCL assumption for the CORESET associated with the monitored search space (i.e., the TCI state indicated for it) having the lowest ControlResourceSetId among the CORESETs configured with the same CORESETPoolIndex value as the CORESET of the PDCCH used to carry the DCI that triggers the aperiodic CSI-RS.

[0074] Case 4-2: A higher layer parameter CORESETPoolIndex with a different value is configured for the CORESET configured on the carrier on which the PDCCH carrying the triggered DCI is received (i.e. on CC#1), and the higher layer parameter CORESETPoolIndex is not configured for any CORESET configured on the carrier on which the aperiodic CSI-RS triggered by the DCI is received (i.e. on CC#2). In case 4-2, the UE may apply the QCL assumption for the CORESET associated with the monitored search space (i.e., the TCI state indicated for it) with the lowest ControlResourceSetId in the latest timeslot of one or more CORESETs within the active BWP of the monitoring serving cell when the aperiodic CSI-RS is received.

[0075] Case 4-3: The higher layer parameter CORESETPoolIndex is not configured for any CORESET configured on the carrier on which the PDCCH carrying the triggered DCI is received (i.e., on CC#1), and the higher layer parameter CORESETPoolIndex with a different value is configured for the CORESET configured on the carrier on which the aperiodic CSI-RS triggered by the DCI is received (i.e., on CC#2). In case 4-3, the UE may apply the QCL assumption for the CORESET associated with the monitored search space (i.e., the TCI state indicated for it) with the lowest ControlResourceSetId among the CORESETs configured with the lowest CORESETPoolIndex (i.e., CORESETPoolIndex=0) in the latest timeslot of one or more CORESETs within the active BWP of the monitoring serving cell when the aperiodic CSI-RS is received.

[0076] In the fifth embodiment, there is no other DL signal with an indicated TCI state in the same symbol as the CSI-RS, and a CORESET is not configured for the BWP in which the aperiodic CSI-RS is to be received.

[0077] Other DL signals refer to any of the following: PDSCH scheduled with a scheduling offset greater than or equal to the threshold timeDurationForQCL as defined in [13, TS 38.306]; PDSCH scheduled with a scheduling offset greater than or equal to the threshold timeDurationForQCL in a CSI-RS symbol when the reporting value is one of {14, 28, 48} aperiodic CSI-RS triggered with a trigger offset of 48+d; aperiodic CSI-RS triggered with a trigger offset greater than or equal to 48+d when the reported value of beamSwitchTiming is one of {224,336}; periodic CSI-RS; and semi-persistent CSI-RS.

[0078] According to the fifth embodiment, a default TCI state for reception of a triggered aperiodic CSI-RS is determined in three different cases.

[0079] Case 5-1: A higher layer parameter CORESETPoolIndex with a different value is configured for the CORESET configured on the active BWP of CC#1 (the carrier on which the PDCCH carrying the DCI triggering the DCI is received) and each of the activated TCI states for the PDSCH on the active BWP of CC#2 (the carrier on which the aperiodic CSI-RS triggered by the DCI is received) is associated with a CORESETPoolIndex value. In case 5-1, the UE may apply the QCL assumption of the activated TCI state with the lowest ID associated with the same CORESETPoolIndex value of the CORESET for the PDCCH carrying the DCI triggering the aperiodic CSI-RS (which may be abbreviated as "the same CORESETPoolIndex value as the DCI triggering the aperiodic CSI-RS") corresponding to the PDSCH in the active BWP applicable to the triggered carrier (i.e., CC#2) when receiving the aperiodic CSI-RS.

[0080] Case 5-2: The higher layer parameter CORESETPoolIndex is not configured for any CORESET configured on the active BWP of CC#1 and each of the activated TCI states for the PDSCH on the active BWP of CC#2 is associated with a CORESETPoolIndex value. In case 5-2, the UE may apply the QCL assumption corresponding to the activated TCI state with the lowest ID associated with CORESETPoolIndex=0 for the PDSCH in the active BWP applicable to the triggered carrier (i.e., CC#2) when receiving aperiodic CSI-RS.

[0081] Case 5-3: The higher layer parameter CORESETPoolIndex is configured for the CORESET configured on the active BWP of CC#1 and the activated TCI state for the PDSCH on the active BWP of CC#2 is not associated with any CORESETPoolIndex value. In case 5-3, the UE may apply the QCL assumption corresponding to the activated TCI state with the lowest ID for the PDSCH in the active BWP applicable to the triggered carrier (i.e., CC#2) when receiving aperiodic CSI-RS.

[0082] In all the above embodiments, the present invention is described from the perspective of the UE. That is, a DCI that schedules a PDSCH or triggers an aperiodic CSI-RS is received at the UE; and the scheduled PDSCH and / or the triggered aperiodic CSI-RS are received at the UE. On the other hand, from the perspective of the gNB (base station), a DCI that schedules a PDSCH or triggers an aperiodic CSI-RS is transmitted from the gNB; and the scheduled PDSCH and the triggered aperiodic CSI-RS are transmitted from the gNB.

[0083] 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 remote 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.

[0084] Method 100 may include: 102 receiving a control signal for scheduling or triggering a downlink signal, wherein the control signal is received on a first carrier and the downlink signal is received on a second carrier, the first carrier being different from the second carrier; and 104 determining a default TCI state for reception of the downlink signal based on a higher layer parameter CORESETPoolIndex if the scheduling or triggering offset is less than a threshold.

[0085] 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.

[0086] Method 200 may include: 202 transmitting a control signal for scheduling or triggering a downlink signal, wherein the control signal is transmitted on a first carrier and the downlink signal is transmitted on a second carrier, the first carrier being different from the second carrier; and 204 determining a default TCI state for transmission of the downlink signal based on a higher layer parameter CORESETPoolIndex if the scheduling or triggering offset is less than a threshold.

[0087] Figure 3 is a schematic block diagram illustrating an apparatus according to one embodiment.

[0088] refer to Figure 3 , UE (ie, remote unit) includes a processor, a memory and a transceiver. The processor is implemented in Figure 1The 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.

[0089] The memory may be located inside or outside the processor and connected to the processor through various well-known means.

[0090] 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.

[0091] 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.

[0092] Embodiments may be practiced in other specific forms. The described embodiments should 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 user equipment, comprising: receiving a control signal that schedules or triggers a downlink signal, wherein the control signal is received on a first carrier and the downlink signal is received on a second carrier, the first carrier being different from the second carrier; and If the scheduling or triggering offset is less than a threshold, determining a default TCI state for reception of the downlink signal according to a higher layer parameter CORESETPoolIndex, The downlink signal is an aperiodic CSI-RS triggered by DCI, and Wherein, when there are two scheduled PDSCHs associated with different CORESETPoolIndex values ​​with an indicated TCI state in the same symbol as the triggered aperiodic CSI-RS and the higher layer parameter CORESETPoolIndex with different values ​​is configured for the CORESET configured on the active BWP of the first carrier, when the aperiodic CSI-RS is received, the QCL assumption of the scheduled PDSCH associated with the same CORESETPoolIndex value as the DCI that triggered the aperiodic CSI-RS is applied.

2. A method performed at a user equipment, comprising: receiving a control signal that schedules or triggers a downlink signal, wherein the control signal is received on a first carrier and the downlink signal is received on a second carrier, the first carrier being different from the second carrier; and If the scheduling or triggering offset is less than a threshold, determining a default TCI state for reception of the downlink signal according to a higher layer parameter CORESETPoolIndex, The downlink signal is an aperiodic CSI-RS triggered by DCI, and Wherein, when there is no other DL signal with an indicated TCI state in the same symbol as the triggered aperiodic CSI-RS and the higher layer parameter CORESETPoolIndex is configured with different values ​​for both the CORESET configured on the first carrier and the CORESET configured on the second carrier, when the aperiodic CSI-RS is received, the QCL assumption associated with the monitored search space having the lowest ControlResourceSetId among the CORESETs configured with the same CORESETPoolIndex value as the DCI that triggered the aperiodic CSI-RS is applied in the latest time slot of one or more CORESETs within the active BWP of the monitored serving cell.

3. A user equipment, comprising: a receiver that receives a control signal that schedules or triggers a downlink signal, wherein the control signal is received on a first carrier and the downlink signal is received on a second carrier, the first carrier being different from the second carrier; and a processor, wherein if the scheduling or triggering offset is less than a threshold, the processor determines a default TCI state for reception of the downlink signal according to a higher layer parameter CORESETPoolIndex, The downlink signal is an aperiodic CSI-RS triggered by DCI, and Wherein, when there are two scheduled PDSCHs associated with different CORESETPoolIndex values ​​with an indicated TCI state in the same symbol as the triggered aperiodic CSI-RS and the higher layer parameter CORESETPoolIndex with different values ​​is configured for the CORESET configured on the active BWP of the first carrier, when the aperiodic CSI-RS is received, the processor applies the QCL assumption of the scheduled PDSCH associated with the same CORESETPoolIndex value as the DCI that triggered the aperiodic CSI-RS.

4. A user equipment, comprising: a receiver that receives a control signal that schedules or triggers a downlink signal, wherein the control signal is received on a first carrier and the downlink signal is received on a second carrier, the first carrier being different from the second carrier; and a processor, wherein if the scheduling or triggering offset is less than a threshold, the processor determines a default TCI state for reception of the downlink signal according to a higher layer parameter CORESETPoolIndex, The downlink signal is an aperiodic CSI-RS triggered by DCI, and Wherein, when there is no other DL signal with an indicated TCI state in the same symbol as the triggered aperiodic CSI-RS and the higher layer parameter CORESETPoolIndex is configured with different values ​​for both the CORESET configured on the first carrier and the CORESET configured on the second carrier, when the aperiodic CSI-RS is received, the processor applies, in the latest timeslot of one or more CORESETs within the active BWP of the monitored serving cell, the QCL assumption for the CORESET associated with the monitored search space having the lowest ControlResourceSetId among the CORESETs configured with the same CORESETPoolIndex value as the DCI that triggered the aperiodic CSI-RS.

5. A method performed at a base station unit, comprising: transmitting a control signal that schedules or triggers a downlink signal, wherein the control signal is transmitted on a first carrier and the downlink signal is transmitted on a second carrier, the first carrier being different from the second carrier; and If the scheduling or triggering offset is less than a threshold, determining a default TCI state for transmission of the downlink signal according to a higher layer parameter CORESETPoolIndex, The downlink signal is an aperiodic CSI-RS triggered by DCI, and Wherein, when there are two scheduled PDSCHs associated with different CORESETPoolIndex values ​​with an indicated TCI state in the same symbol as the triggered aperiodic CSI-RS and the higher layer parameter CORESETPoolIndex with different values ​​is configured for the CORESET configured on the active BWP of the first carrier, when the aperiodic CSI-RS is transmitted, the QCL assumption of the scheduled PDSCH associated with the same CORESETPoolIndex value as the DCI that triggered the aperiodic CSI-RS is applied.

6. A method performed at a base station unit, comprising: transmitting a control signal that schedules or triggers a downlink signal, wherein the control signal is transmitted on a first carrier and the downlink signal is transmitted on a second carrier, the first carrier being different from the second carrier; and If the scheduling or triggering offset is less than a threshold, determining a default TCI state for transmission of the downlink signal according to a higher layer parameter CORESETPoolIndex, The downlink signal is an aperiodic CSI-RS triggered by DCI, and Wherein, when there is no other DL signal with an indicated TCI state in the same symbol as the triggered aperiodic CSI-RS and the higher layer parameter CORESETPoolIndex is configured with different values ​​for both the CORESET configured on the first carrier and the CORESET configured on the second carrier, when the aperiodic CSI-RS is transmitted, the QCL assumption associated with the monitored search space having the lowest ControlResourceSetId among the CORESETs configured with the same CORESETPoolIndex value as the DCI that triggers the aperiodic CSI-RS is applied in the latest time slot of one or more CORESETs within the active BWP of the monitoring serving cell.

7. A base station unit, comprising: a transmitter that transmits a control signal that schedules or triggers a downlink signal, wherein the control signal is transmitted on a first carrier and the downlink signal is transmitted on a second carrier, the first carrier being different from the second carrier; and a processor, wherein if the scheduling or triggering offset is less than a threshold, the processor determines a default TCI state for transmission of the downlink signal according to a higher layer parameter CORESETPoolIndex, The downlink signal is an aperiodic CSI-RS triggered by DCI, and Wherein, when there are two scheduled PDSCHs associated with different CORESETPoolIndex values ​​with indicated TCI states in the same symbol as the triggered aperiodic CSI-RS and the higher layer parameter CORESETPoolIndex with different values ​​is configured for the CORESET configured on the active BWP of the first carrier, when transmitting the aperiodic CSI-RS, the processor applies the QCL assumption of the scheduled PDSCH associated with the same CORESETPoolIndex value as the DCI that triggered the aperiodic CSI-RS.

8. A base station unit, comprising: a transmitter that transmits a control signal that schedules or triggers a downlink signal, wherein the control signal is transmitted on a first carrier and the downlink signal is transmitted on a second carrier, the first carrier being different from the second carrier; and a processor, wherein if the scheduling or triggering offset is less than a threshold, the processor determines a default TCI state for transmission of the downlink signal according to a higher layer parameter CORESETPoolIndex, The downlink signal is an aperiodic CSI-RS triggered by DCI, and Wherein, when there is no other DL signal with an indicated TCI state in the same symbol as the triggered aperiodic CSI-RS and the higher layer parameter CORESETPoolIndex is configured with different values ​​for both the CORESET configured on the first carrier and the CORESET configured on the second carrier, when the aperiodic CSI-RS is transmitted, the processor applies, in the latest timeslot of one or more CORESETs within the active BWP of the monitored serving cell, the QCL assumption for the CORESET associated with the monitored search space having the lowest ControlResourceSetId among the CORESETs configured with the same CORESETPoolIndex value as the DCI that triggered the aperiodic CSI-RS.

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