Method and apparatus for transmitting and receiving signals in a wireless communication system

Abstract

The present disclosure relates to a communication technology and a system thereof for merging a fifth generation (5G) communication system with an Internet of Things (IoT) technology to support high data transmission rates in a post-fourth generation (4G) system. The present disclosure can be applied to smart services based on 5G communication technology and IoT-related technologies (e.g., smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail, security and safety-related services, etc.). A method and apparatus for sending and receiving signals in a wireless communication system are provided.

Description

Technical Field

[0001] The present disclosure relates to a method and apparatus for transmitting and receiving a signal in a wireless communication system. More specifically, the present disclosure relates to a method and apparatus for transmitting and receiving one or more data between a transmission node and a user equipment (UE) to perform cooperative communication in a wireless communication system. Background Art

[0002] In order to meet the soaring demand for wireless data traffic since the fourth generation (4G) communication system entered the market, people are working hard to develop an improved fifth generation (5G) communication system or pre-5G communication system. For this reason, the 5G communication system or pre-5G communication system is called a super 4G network communication system or a post-long term evolution (LTE) system. For higher data transmission rates, the 5G communication system is considered to be implemented on an ultra-high frequency band (mmWave), such as 70GHz. In order to alleviate the path loss of the ultra-high frequency band and increase the coverage of radio waves, the 5G communication system considers the following technologies: beamforming, massive multiple input multiple output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antennas. In order to have an enhanced network, various technologies of the 5G communication system are also under development, such as evolved or advanced small base stations, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device (D2D) communications, wireless backhaul, mobile networks, cooperative communications, multi-point coordination (CoMP), and interference elimination. There are various other schemes under development for 5G systems, such as hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) modulation (FQAM) and advanced coded modulation (ACM) schemes such as sliding window superposition coding (SWSC), as well as advanced access schemes such as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA).

[0003] The Internet is evolving from a human-centric connected network where humans create and consume information to an Internet of Things (IoT) network where information is communicated and processed between things or other distributed components. Another emerging technology is the Internet of Everything (IoE), which is a combination of big data processing technology and IoT technology, such as through connection to a cloud server. To realize IoT, technical elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology are required. Recently, research on inter-object connection technology, such as sensor networks, machine-to-machine (M2M), or machine-type communication (MTC), is being conducted. In the IoT environment, smart Internet technology (IT) services can be provided to collect and analyze data generated by connected things, thereby creating new value for human life. IoT can have various applications, such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare or smart home appliance industries, or state-of-the-art medical services, by transforming or integrating existing information technology (IT) technologies and various industries.

[0004] Therefore, efforts are being made to apply 5G communication systems to IoT networks. For example, sensor networks, machine-to-machine (M2M), machine-type communications (MTC), or other 5G technologies are implemented through schemes such as beamforming, multiple-input multiple-output (MIMO), and array antenna schemes. The above-mentioned cloud radio access network (RAN) as an application of big data processing technology can be said to be an example of the integration of 5G and IoT technologies.

[0005] As described above, with the development of wireless communication systems, a data transmission and reception solution for network cooperative communication is needed.

[0006] The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with respect to the present disclosure. Summary of the invention

[0007] Technical issues

[0008] An aspect of the present disclosure is to solve at least the above problems and / or disadvantages and to provide at least the advantages described below. Therefore, an aspect of the present disclosure is to provide a method and apparatus for transmitting and receiving one or more data between a transmission node and a user equipment (UE) to perform cooperative communication in a wireless communication system.

[0009] The objects of the present disclosure are not limited to the above objects, and other objects not mentioned will be apparent to those skilled in the art through the following description.

[0010] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments.

[0011] Technical Solution

[0012] According to one aspect of the present disclosure, a method performed by a terminal UE in a wireless communication system is provided. The method includes receiving physical downlink control channel (PDCCH) configuration information including two different values ​​of a control resource set (CORESET) pool index from a base station (BS), receiving information indicating enabling a predefined quasi-co-location (QCL) relationship for application based on the CORESET pool index from the BS, receiving a PDCCH triggering an aperiodic channel state information reference signal (CSI-RS) from the BS, and receiving an aperiodic CSI-RS from the BS, wherein if the scheduling offset between the last symbol of the PDCCH and the start symbol of the aperiodic CSI-RS is less than the duration of the QCL application, the QCL relationship applied for the aperiodic CSI-RS is determined according to the CORESET pool index associated with the PDCCH.

[0013] According to another aspect of the present disclosure, a method performed by a terminal UE in a wireless communication system is provided. The method includes receiving physical downlink control channel (PDCCH) configuration information including two different values ​​of a control resource set (CORESET) pool index from a base station (BS), receiving information indicating enabling a predefined quasi-co-location (QCL) relationship for application based on the CORESET pool index from the BS, receiving a PDCCH from the BS, and receiving a physical downlink shared channel (PDSCH) scheduled by the PDCCH from the BS, wherein if the offset between the reception of the PDCCH and the reception of the PDSCH is less than a threshold for applying the QCL relationship, the QCL relationship applied for the PDSCH is determined according to the CORESET with the lowest CORESET index among the CORESETs configured with the same value as the CORESET pool index of the PDCCH.

[0014] According to another aspect of the present disclosure, a method performed by a base station (BS) in a wireless communication system is provided. The method includes generating physical downlink control channel (PDCCH) configuration information including two different values ​​of a control resource set (CORESET) pool index, generating first information indicating enabling a predefined quasi co-location (QCL) relationship to apply based on the CORESET pool index, sending the PDCCH configuration information to a terminal, and sending the first information to the terminal. According to another aspect of the present disclosure, a terminal in a wireless communication system is provided. The terminal includes a transceiver and a processor, wherein the processor is configured to: receive physical downlink control channel (PDCCH) configuration information including two different values ​​of a control resource set (CORESET) pool index from a base station (BS) via the transceiver, receive information indicating enabling a predefined quasi co-location (QCL) relationship to apply based on the CORESET pool index from the BS via the transceiver, receive a PDCCH triggering an aperiodic channel state information reference signal (CSI-RS) from the BS via the transceiver, and receive the aperiodic CSI-RS from the BS via the transceiver, wherein if a scheduling offset between a last symbol of the PDCCH and a start symbol of the aperiodic CSI-RS is less than a duration of the QCL application, the QCL relationship applied for the aperiodic CSI-RS is determined according to the CORESET pool index associated with the PDCCH. According to another aspect of the present disclosure, a base station (BS) in a wireless communication system is provided. The BS includes a transceiver and a processor, wherein the processor is configured to: generate physical downlink control channel (PDCCH) configuration information including two different values ​​of a control resource set (CORESET) pool index, generate first information indicating enabling a predefined quasi co-location (QCL) relationship to be applied based on the CORESET pool index, send the PDCCH configuration information to a terminal via the transceiver, and send the first information to the terminal via the transceiver.

[0015] According to an embodiment of the present disclosure, a method and apparatus for transmitting and receiving one or more data between a transmission node and a UE for cooperative communication in a wireless communication system may be provided.

[0016] Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings, in which:

[0018] Figure 1is a diagram showing a transmission structure in a time-frequency domain in a Long Term Evolution (LTE), Evolved Universal Terrestrial Radio Access (E-UTRA), Advanced LTE (LTE-A), or similar wireless communication system according to an embodiment of the present disclosure;

[0019] Figure 2 is a diagram showing a frame, a subframe, and a time slot structure in a 5th generation (5G) communication system according to an embodiment of the present disclosure;

[0020] Figure 3 is a diagram showing a bandwidth part (BWP) configuration in a wireless communication system according to an embodiment of the present disclosure;

[0021] Figure 4 is a diagram illustrating a method of indicating and changing a bandwidth portion in a wireless communication system according to an embodiment of the present disclosure;

[0022] Figure 5 is a diagram showing a method configuration of a control region of a downlink control channel in a wireless communication system according to an embodiment of the present disclosure;

[0023] Figure 6 is a diagram showing a method of allocating resources on a physical downlink shared channel (PDSCH) frequency axis in a wireless communication system according to an embodiment of the present disclosure;

[0024] Figure 7 is a diagram showing a method for allocating resources on a PDSCH time axis in a wireless communication system according to an embodiment of the present disclosure;

[0025] Figure 8 is a diagram showing a method of allocating resources on a time axis according to subcarrier spacings of a data channel and a control channel in a wireless communication system according to an embodiment of the present disclosure;

[0026] Fig. 9 is a diagram showing a cooperative communication antenna port configuration according to an embodiment of the present disclosure;

[0027] Fig. 10A is a diagram showing a medium access control (MAC) control element CE structure for a transmission configuration indication (TCI) state activation for a UE-specific physical downlink control channel (PDCCH) according to an embodiment of the present disclosure;

[0028] Fig. 10B is a diagram showing the configuration of beamforming indication and TCI state according to an embodiment of the present disclosure;

[0029] Fig.11 is a diagram showing a method of cooperative communication based on a single PDCCH according to an embodiment of the present disclosure;

[0030] Fig.12 is a diagram showing cooperative communication based on multiple PDCCHs according to an embodiment of the present disclosure;

[0031] Fig.13 is a diagram showing cooperative communication based on multiple PDCCHs according to an embodiment of the present disclosure;

[0032] Fig.14 is a diagram showing cooperative communication based on multiple PDCCHs according to an embodiment of the present disclosure;

[0033] Fig.15 is a flowchart illustrating a method of operating a UE according to an embodiment of the present disclosure;

[0034] Fig.16 , 17 18 is a diagram showing a process for transmitting a plurality of PDSCHs from a plurality of transmission and reception points (TRPs) to a specific UE via a single PDCCH according to various embodiments of the present disclosure;

[0035] Fig.19 is a flowchart illustrating a method of operating a UE according to an embodiment of the present disclosure;

[0036] Fig. 20 is a diagram showing a method for receiving a PDSCH based on NC-JT transmission and a default quasi-co-location (QCL) configuration of a UE according to an embodiment of the present disclosure;

[0037] Fig.21A and 21B is a diagram illustrating a method for receiving an aperiodic or periodic CSI-RS and a PDSCH based on NC-JT and a default QCL configuration of a UE according to various embodiments of the present disclosure;

[0038] Fig. 22 is a diagram showing a structure of a UE in a wireless communication system according to an embodiment of the present disclosure;

[0039] Fig.23 is a diagram showing a structure of a base station in a wireless communication system according to an embodiment of the present disclosure.

[0040] Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures. DETAILED DESCRIPTION

[0041] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of the various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in understanding, but these are to be regarded as exemplary only. Therefore, it will be appreciated by those of ordinary skill in the art that various changes and modifications may be made to the various embodiments described herein without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and configurations may be omitted for clarity and brevity.

[0042] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but are used only by the inventor to enable a clear and consistent understanding of the present disclosure. Therefore, it should be clear to those skilled in the art that the following description of various embodiments of the present disclosure is for illustrative purposes only and is not intended to limit the present disclosure as defined by the appended claims and their equivalents.

[0043] It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

[0044] For the same reason, some elements may be exaggerated or schematically shown. The size of each element does not necessarily reflect the actual size of the element. In all drawings, the same reference numerals are used to refer to the same elements.

[0045] The advantages and features of the present disclosure and methods for implementing the same can be understood by the following embodiments described in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed herein, and various changes may be made thereto. The embodiments disclosed herein are provided only to inform those of ordinary skill in the art of the scope of the present disclosure. The present disclosure is limited only by the attached claims. Throughout the specification, the same reference numerals represent the same elements.

[0046] It should be understood that the blocks in each flowchart and the combination of flowcharts can be executed by computer program instructions. Since computer program instructions can be equipped in a processor of a general-purpose computer, a special-purpose computer or other programmable data processing device, the instructions executed by the processor of the computer or other programmable data processing device generate functions for performing the block descriptions in conjunction with each flowchart. Since computer program instructions can be stored in a computer-usable or computer-readable memory, which can implement functions in a specified manner for a computer or other programmable data processing device, the instructions stored in the computer-usable or computer-readable memory can produce a product including an instruction device, which is used to perform the functions described in conjunction with the blocks in each flowchart. Since computer program instructions can be equipped in a computer or other programmable data processing device, the instructions for generating a process executed by a computer as a series of operations are executed on a computer or other programmable data processing device and run the computer or other programmable data processing device. The data processing device can provide operations for performing functions related to one (multiple) blocks in each flowchart.

[0047] In addition, each block can represent a module, a fragment, or a portion of a code that includes one or more executable instructions for performing one or more specified logical functions. In addition, it should be noted that in some alternative execution examples, the functions mentioned in the blocks can appear in different orders. For example, two blocks shown in succession can be executed substantially simultaneously or in reverse order, depending on the corresponding functions.

[0048] As used herein, the term "unit" refers to a software element or a hardware element, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). The unit plays a certain role. However, the term "unit" is not limited to referring to a software or hardware element. A "unit" can be configured in a storage medium that can be addressed or configured to reproduce one or more processors. Therefore, as an example, a "unit" includes elements, such as software elements, object-oriented software elements, class elements and task elements, processes, functions, attributes, processes, subroutines, program code segments, drivers, firmware, microcodes, circuits, data, databases, data architectures, tables, arrays, and variables. The functions provided in an element or "unit" can be combined with additional elements, or can be divided into sub-elements or sub-units. In addition, an element or "unit" can be implemented as one or more central processing units (CPUs) in a reproduction device or a secure multimedia card. According to an embodiment of the present disclosure, a "unit" may include one or more processors.

[0049] The working principle of the present disclosure is described below in conjunction with the accompanying drawings. When it is determined that the subject matter of the present disclosure is unclear, the details of known functions or configurations can be skipped. The terms used herein are defined in consideration of the functions in the present disclosure and can be replaced by other terms according to the intention or practice of the user or operator. Therefore, these terms should be defined based on the overall disclosure. In the following, a base station may be an entity that allocates resources to a terminal and may be at least one of a gNode B (gNB), an eNode B (eNB), a Node B, a base station (BS), a wireless access unit, a base station controller, or a network node. The terminal may include a user equipment (UE), a mobile station (MS), a terminal, a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function. However, the embodiments of the present disclosure are not limited thereto. According to an embodiment of the present disclosure, a technology for receiving broadcast information from a base station by a UE in a wireless communication system is described. The present disclosure relates to a technology for combining a 5th generation (5G) communication system with an Internet of Things (IoT) technology to support high data transmission rate technology and a communication system thereof in a post-4th generation (4G) system. The present disclosure can be applied to smart services (e.g., smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail, security and safety-related services, etc.) based on 5G communication technology and IoT-related technology.

[0050] In the following, the terms representing broadcast information, the terms representing control information, the terms related to communication coverage, the terms representing state changes (e.g., events), the terms representing network entities, the terms representing messages, or the terms representing device components are provided for illustrative purposes only. The present disclosure is not limited to these terms, and other terms that are technically equivalent may also be used.

[0051] For ease of description, some terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) standard may be used hereinafter. However, the present disclosure is not limited by these terms and names and may also be applicable to systems conforming to other standards.

[0052] Wireless communication systems have evolved from voice-centric services to broadband wireless communication systems to provide high data rate and high-quality packet data services, such as 3GPP High Speed ​​Packet Access (HSPA), LTE or Evolved Universal Terrestrial Radio Access (E-UTRA), LTE-advanced (LTE-A), LTE-pro, 3GPP2 High Rate Packet Data (HRPD), Ultra Mobile Broadband (UMB), and Institute of Electrical and Electronics Engineers (IEEE) 802.16e communication standards.

[0053] As a representative example of such a broadband wireless communication system, the LTE system adopts orthogonal frequency division multiplexing (OFDM) in the downlink and single carrier frequency division multiple access (SC-FDMA) in the uplink. The uplink refers to the wireless link for the user equipment (UE) (or mobile station (MS)) to transmit data or control signals to the base station (BS, or eNode B), and the downlink refers to the wireless link for the base station to transmit data or control signals to the UE. This multiple access scheme allocates and operates the time-frequency resources carrying data or control information for each user so as not to overlap, that is, to maintain orthogonality, thereby distinguishing the data or control information of each user.

[0054] Post-LTE communication systems, such as 5G communication systems, need to freely reflect the various needs of users and service providers, thereby supporting services that meet various needs. Services considered for 5G communication systems include, for example, increased mobile broadband (eMBB), massive machine type communication (MMTC), and ultra-reliable low latency communication (URLLC).

[0055] According to an embodiment of the present disclosure, eMBB is intended to provide a further enhanced data transmission rate compared to LTE, LTE-A or LTE-pro. For example, with respect to one base station, the eMBB of a 5G communication system needs to provide a download peak data rate of 20Gbps and an uplink peak data rate of 10Gbps. The 5G communication system also needs to provide an increased user-perceived data rate for the UE. In order to meet these requirements, it is necessary to further enhance the transmit (TX) / receive (RX) technology and multiple-input multiple-output (MIMO). The data transmission rate required by the 5G communication system can be met by using a frequency band wider than 20MHz in a frequency band of 3Ghz to 6Ghz or a frequency band above 6Ghz, instead of the 2Ghz band currently used by LTE.

[0056] mMTC is also considered to support application services such as the Internet of Things (IoT) in 5G communication systems. In order to efficiently provide IoT, mMTC may be required to support a large number of UEs within a cell, enhance the coverage and battery time of the UE, and reduce the cost of the UE. IoT terminals are connected to various sensors or devices to provide communication functions, so it is necessary to support multiple UEs in each cell (e.g., 1,000,000 user equipment per square meter). Since UEs supporting mMTC, depending on the nature of the service, are likely to be located in shadow areas not covered by the cell, such as underground in a building, it may require a wider coverage compared to other services provided by the 5G communication system. UEs supporting mMTC may need to have very long battery life due to the need for low cost and the difficulty of frequent battery replacement.

[0057] URLLC is a cellular-based wireless communication service for specific purposes (mission-critical), which can be used for remote control of robots or machinery, industrial automation, drones, remote healthcare, and emergency alerts, and may need to provide communications with ultra-low latency and ultra-high reliability. For example, services supporting URLLC need to meet the requirements of less than 0.5 milliseconds of air interface latency and 10 -5 Or a smaller packet error rate. Therefore, for services supporting URLLC, the 5G communication system may need to be designed to provide a shorter transmission time interval (TTI) than other services and allocate a wider range of resources in the frequency band. However, the aforementioned mMTC, URLLC and eMBB are only examples of different service types, and the service types to which the present disclosure is applied are not limited to the above examples.

[0058] The services considered in the above 5G communication system should be merged together based on a framework. That is, for efficient resource management and control, it is better to integrate the services into a single system and control and transmit them instead of running them separately.

[0059] Although the embodiments of the present disclosure are described by taking LTE, LTE-A, LTE Pro or New Radio (NR) systems as examples, the embodiments of the present disclosure may also be applied to other communication systems with similar technical backgrounds or channel forms. In addition, according to the judgment of ordinary technicians in this field, the embodiments of the present disclosure may be modified within the scope that does not significantly deviate from the scope of the present disclosure, and such modifications may be applicable to other communication systems.

[0060] The present disclosure relates to a method and apparatus for repeatedly transmitting data and control signals between a UE and a plurality of transmission nodes performing cooperative communication to improve communication reliability.

[0061] According to the embodiments of the present disclosure, when network cooperative communication is used in a wireless communication system, the reliability of UE receiving data / control signals can be enhanced.

[0062] The frame structure of the 5G system is described below with reference to the accompanying drawings.

[0063] Figure 1 is a diagram showing a transmission structure in the time-frequency domain of a wireless communication system according to an embodiment of the present disclosure.

[0064] Reference Figure 1 , the time-frequency domain transmission structure is as follows Figure 1 As shown, Figure 1 The time-frequency domain transmission structure of LTE, LTE-A, NR or other similar wireless communication systems is shown. Figure 1 The basic structure of the time-frequency domain is shown. The time-frequency domain is the wireless resource area for transmitting data or control channel signals in the 5G system. Figure 1, the horizontal axis refers to the time domain, and the vertical axis refers to the frequency domain. The basic unit of resources in the time domain and frequency domain is the resource element (RE) 1-01. An RE can be defined as a resource that occupies an orthogonal frequency division multiplexing (OFDM) symbol 1-02 on the time axis (time domain) and a subcarrier 1-03 on the frequency axis (frequency domain). In the frequency domain, (eg, 12) consecutive REs may constitute a resource block (RB) 1-04.

[0065] Figure 2 is a diagram showing the frame, subframe and time slot structure in a 5G communication system according to an embodiment of the present disclosure.

[0066] Reference Figure 2 , which shows an exemplary structure of a frame 2-00, a subframe 2-01, and a time slot 2-02. A frame may have a length of 10 milliseconds. A subframe 1-10 may be Figure 1 As shown, the length may be 1 ms, so a frame may consist of a total of 10 subframes. A time slot may include 14 OFDM symbols (e.g., the number of symbols contained in a time slot is For 14 One subframe 1-10 may include one or more time slots, and the number of time slots included in one subframe 1-10 may vary according to a value μ set for the subcarrier spacing.

[0067] Figure 2 An example in which the value μ set for the subcarrier spacing is 0 (μ=0) (2-04) and an example in which the value μ set for the subcarrier spacing is 1 (μ=1) (2-05) are shown. When μ=0 (2-04), the subframe 2-01 may include one time slot 2-02, and when μ=1 (2-05), the subframe 2-01 may include two time slots, for example, two time slots include time slot 2-03. That is, the number of time slots included in one subframe can vary, so the number of time slots included in a frame can be changed. And according to the value μ set for the subcarrier spacing and It can be defined as shown in Table 1 below.

[0068] [Form 1]

[0069]

[0070] In the NR communication system, one component carrier (CC) or serving cell can include up to 250 RBs. Therefore, if the UE always receives the signal of the entire serving cell bandwidth like the LTE communication system, the power consumption of the UE may be very large. To solve this problem, the base station can set one or more bandwidth parts (BWPs) to allow the UE to change the reception area in the cell. In the NR communication system, the base station can set the initial BWP, that is, the bandwidth of the control resource set (CORESET) #0 (or common search space (CSS)) in the UE through the master information block (MIB).

[0071] Thereafter, the base station may set the initial BWP (or first BWP) of the UE through radio resource control (RRC) signaling and provide information about at least one or more BWP configurations, which may be indicated in the future through downlink control information (DCI). Thereafter, the base station may indicate to the UE what frequency band the UE will use by providing a BWP identifier (ID) via DCI. If the UE does not receive DCI in the currently allocated BWP for a certain time or longer, the UE may switch back to the default BWP and attempt to receive DCI in the default BWP.

[0072] Figure 3 is a diagram showing a BWP configuration in a wireless communication system according to an embodiment of the present disclosure.

[0073] Reference Figure 3 , the wireless communication system may be, for example, a 5G communication system. Figure 3 An example is shown in which the UE bandwidth 3-00 is divided into two bandwidth parts, such as bandwidth part #1 (BWP#1) 3-05 and bandwidth part #2 (BWP#2) 3-10. The base station can configure one or more bandwidth parts in the UE, and for each bandwidth part, the information shown in Table 2 below can be configured.

[0074] [Table 2]

[0075]

[0076] In addition to the configuration information described in Table 2, various parameters related to the bandwidth part may be configured in the UE. The above information may be delivered from the base station to the UE via higher layer signaling, such as RRC signaling. At least one of the configured one or more bandwidth parts may be activated. Whether to activate the configured bandwidth part may be delivered from the base station to the UE semi-statically via RRC signaling or dynamically via a media access control (MAC) control element (CE) or DCI.

[0077] The configuration of the bandwidth portion supported by the above-mentioned 5G communication system can be used for various purposes.

[0078] For example, when the bandwidth supported by the UE is less than the system bandwidth, the bandwidth supported by the UE may be supported by configuring the bandwidth part. For example, since the frequency position of the bandwidth part in Table 2 is configured in the UE through configuration information 2, the UE may send and receive data at a specific frequency position within the system bandwidth.

[0079] As another example, in order to support different parameter sets, the base station can configure multiple bandwidth parts in the UE. For example, in order to support data transmission / reception using 15kHz subcarrier spacing and data transmission / reception using 30kHz subcarrier spacing for any UE, two bandwidth parts can be configured for the UE, in which case one of the two bandwidth parts can be configured to use a subcarrier spacing of 15kHz, while the other bandwidth part is configured to use a subcarrier spacing of 30kHz. Different bandwidth parts can be frequency division multiplexed (FDM), and when data is to be sent / received at a specific subcarrier spacing, the bandwidth part configured to use the corresponding subcarrier spacing can be activated.

[0080] As another example, in order to reduce the power consumption of the UE, the base station can configure bandwidth parts with different bandwidth sizes in the UE. For example, when the UE supports a very large bandwidth, such as a bandwidth exceeding a threshold bandwidth, such as 100 MHz, and always sends and receives data through the corresponding bandwidth, significant power consumption will occur. Especially in the absence of traffic, for a large bandwidth of 100 MHz, it is very inefficient in terms of power consumption for the UE to monitor unnecessary downlink control channels. Therefore, in order to reduce the power consumption of the UE, the base station can configure a bandwidth part with a smaller bandwidth for the UE in the UE, such as a bandwidth part of 20 MHz. In the absence of traffic, the UE can perform monitoring operations in the 20 MHz bandwidth part, and when data is generated, the UE can use the 100 MHz bandwidth part to send and receive data according to the instructions of the base station.

[0081] Figure 4 is a diagram illustrating a method for indicating and changing a bandwidth portion in a wireless communication system according to an embodiment of the present disclosure.

[0082] Figure 4 The illustrated operations of indicating and changing the bandwidth portions may be, for example, operations for dynamically changing the configuration of the bandwidth portions.

[0083] Reference Figure 4 As described above in conjunction with Table 2, the base station may configure one or more bandwidth parts in the UE and provide the UE with information such as the bandwidth of the bandwidth part, the frequency position of the bandwidth part, and the parameter set of the bandwidth part as the configuration of each bandwidth part.

[0084] Figure 4An example is shown in which two bandwidth parts, bandwidth part #1 (BPW#1) 4-05 and bandwidth part #2 (BWP#2) 4-10, are configured in the UE bandwidth 4-00 for one UE. One or more bandwidth parts of the configured bandwidth may be activated. Figure 4 An example is shown in which one bandwidth section is activated.

[0085] Reference Figure 4 , among the bandwidth parts configured in time slot #0 4-25, bandwidth part #1 (BWP#1) 4-05 is activated, and the UE can monitor the physical downlink control channel (PDCCH) in the control region #1 (CORESET#1) 4-45 configured in the bandwidth part #1 (BWP#1) 4-05, and transmit / receive data 4-55 in the bandwidth part #1 (BWP#1) 4-05. The control region in which the UE receives the PDCCH signal may differ depending on which of the configured bandwidth parts is activated, and thus, the bandwidth in which the UE monitors the PDCCH may vary.

[0086] The base station may additionally send an indicator for changing the configuration of the bandwidth part, such as a configuration change indicator, to the UE. Here, the operation of changing the configuration of the bandwidth part may be regarded as the same as the operation of activating a specific bandwidth part (e.g., changing the activated bandwidth part from bandwidth part A to bandwidth part B). The base station may send a configuration change indicator, such as a configuration switching indicator, to the UE in a specific time slot, and the UE may receive the configuration change indicator from the base station. After receiving the configuration change indicator, the UE may determine the bandwidth part to be activated by applying the configuration changed from a specific time according to the configuration change indicator, and perform a monitoring operation on the PDCCH in the control area configured in the activated bandwidth part.

[0087] Reference Figure 4 , the base station may send a configuration change indicator, for example, a configuration switch indicator 4-15, to indicate that the activated bandwidth part is changed from the existing bandwidth part #1 (BWP#1) 4-05 to the bandwidth part #2 (BWP#2) 4-10 in the time slot #1 4-30. After receiving the configuration change indicator, the UE may activate the bandwidth part #2 (BWP#2) 6-10 based on the configuration change indicator. In this case, a switching time 4-20 for changing the bandwidth part may be required, and a time point for activating the activated bandwidth part may be determined based on the required switching time 4-20.

[0088] Figure 4An example of a transition time 4-20 requiring one time slot after receiving a configuration change indicator (e.g., a configuration switching indicator) 4-15 is shown. Data transmission / reception may not be performed during the transition time 4-20 (4-60). Therefore, bandwidth part #2 (BWP#2) 4-10 may be activated in time slot #2 4-35, and operations of transmitting / receiving control channel signals and data may be performed in the activated bandwidth part #2 (BWP#2) 4-10.

[0089] The base station may pre-configure one or more bandwidth parts in the UE through higher layer signaling (e.g., RRC signaling), and may indicate the activation of the bandwidth part by mapping the configuration change indicator 4-15 to one of the bandwidth parts pre-configured by the base station. 2 The configuration change indicator implemented with N bits may indicate one of the N preconfigured bandwidth parts. Table 3 below shows an example of indicating configuration information on bandwidth parts using the configuration change indicator implemented with two bits.

[0090] [Table 3]

[0091] The value of the indicator Bandwidth Part Configuration 00 Bandwidth configuration set by higher layer signaling A 01 Bandwidth configuration set by higher layer signaling B 10 Bandwidth configuration C set by higher layer signaling 11 Bandwidth configuration set by higher layer signaling D

[0092] Configuration change indicators 4-15 for the bandwidth part are as described above in conjunction with Figure 4 As described above, it can be transmitted from the base station to the UE in the form of medium access control (MAC) control element (CE) signaling or L1 signaling (e.g., common DCI, group common DCI, or UE-specific DCI). Figure 4 The configuration change indicator 4-15 for the bandwidth portion described, from what point in time the bandwidth portion activation is applied, can be determined as follows.

[0093] The time for applying the bandwidth part activation can be set to a predefined value (for example, applying it N (≥1) time slots after receiving the configuration change indicator) (method 1), set in the UE by the base station through higher layer signaling (for example, RRC signaling) (method 2), or included in the configuration change indicator 4-15 and sent (method 3). Alternatively, it can be determined by a combination of the above methods, such as methods 1 to 3. After receiving the configuration change indicator 4-15 of the bandwidth part, the UE can start applying the changed configuration from the time obtained by any one of the above methods or a combination thereof.

[0094] The downlink control channel in the 5G communication system is explained below with reference to the accompanying drawings.

[0095] Figure 5is a diagram showing a method configuration of a control region of a downlink control channel in a wireless communication system according to an embodiment of the present disclosure.

[0096] Reference Figure 5 , an example configuration of a control region for a downlink control channel in a wireless communication system may be an exemplary configuration of a control region, such as CORESET, through which a downlink control channel is transmitted in a 5G communication system. Figure 5 An example is shown in which a bandwidth portion 5-10 of a UE is configured on the frequency axis and two control regions (control region #1 (CORESET#1) 5-01 and control region #2 (CORESET#2) 5-02) are configured in one time slot 5-20 on the time axis. The control regions 5-01 and 5-02 may be configured in a specific frequency resource 5-03 within the entire UE bandwidth portion 5-10 on the frequency axis. The control regions 5-01 and 5-02 may be configured with one or more OFDM symbols on the time axis and may be defined as a control region length, such as a CORESET duration 5-04. Figure 5 In the example of , control region #1 5-01 is configured as a control region length of two symbols, and control region #2 5-02 is configured as a control region length of one symbol.

[0097] The control region in the above-mentioned 5G communication system can be configured in the UE by the base station through higher layer signaling (e.g., system information, master information block (MIB), or radio resource control (RRC) signaling). Configuring the control region in the UE means providing the UE with information such as an identification (ID) of the control region, a frequency position of the control region, and a symbol length of the control region. For example, the information shown in Table 4 can be provided.

[0098] [Table 4]

[0099]

[0100] In Table 4, the tci-StatesPDCCH field indicates QCL configuration information. The tci-StatesPDCCH (abbreviated as transmission configuration indicator (TCI) state) field may include one or more synchronization signals (Ss) / physical broadcast channel (PBCH) blocks or channel state information reference signals (CSI-RS) that are quasi-co-located (QCLed) with the demodulation reference signal (DMRS) transmitted in the corresponding control region. In Table 4, the controlResourceSetId field represents the control region, such as the control resource set ID, the frequencyDomainResources field represents the resource allocation information in the frequency domain, the duration represents the resource allocation information in the time domain, the cce-REG-MappingType field represents the method of mapping the control channel element (CCE) to the resource element group (REG), the reg-BundleSize field represents the REG bundling size, the interleaverSize field represents the size of the interleaver, and the shiftIndex represents the interleaver shift. In a wireless communication system, one or more different antenna ports can be replaced by one or more channels, or one or more signals or a combination thereof. For convenience, different antenna ports are described as an example and can be associated with each other through the QCL configuration illustrated in Table A-1 below.

[0101] [Table A-1]

[0102]

[0103] Specifically, the QCL configuration may associate two different antenna ports with each other in the relationship between a (QCL) target antenna port and a (QCL) reference antenna port. The UE may apply (or assume) all or some statistical characteristics measured at the reference antenna port when receiving at the target antenna port (e.g., Doppler shift, Doppler spread, average delay, delay spread, average gain, spatial Rx (or Tx) parameters or such channel large-scale parameters or the UE's Rx spatial filter coefficients or Tx spatial filter coefficients). The target antenna port refers to an antenna port that transmits a channel or signal set by a higher layer configuration including the QCL configuration, or an antenna port that transmits a channel or signal indicating a TCI state to which the QCL configuration is applied. The reference antenna port refers to an antenna port that transmits a channel or signal indicated (specified) by a referenceSignal parameter in the QCL configuration. In Table A-1, the referenceSignal field may be an indicator indicating a channel state information reference signal (CSI-RS) or one of the SS / PBCH blocks as a QCL reference RS.

[0104] Specifically, the statistical characteristics of the channel defined by the QCL configuration (indicated by the parameter qcl-Type in Table A-1QCL configuration) can be classified according to the QCL type as follows.

[0105] .'QCL-TypeA',{Doppler shift, Doppler spread, average delay, delay spread}

[0106] .'QCL-TypeB',{Doppler shift, Doppler spread}

[0107] .'QCL-TypeC',{Doppler shift, average delay}

[0108] .'QCL-TypeD',{spatial Rx parameters}

[0109] In this case, the QCL types are not limited to the above four, but in order not to make the subject of the description unclear, all possible combinations are not listed.

[0110] QCL-TypeA is a QCL type used when the bandwidth and transmission duration of the target antenna port are sufficient compared to the reference antenna port (for example, on both the frequency axis and the time axis, when the number of target antenna ports is greater than the number of reference antenna port samples, the transmission bandwidth of the target antenna port is wider than the transmission bandwidth of the reference antenna port on both the frequency axis and the time axis, and the transmission time (or duration) of the target antenna port is longer than the transmission time (or duration) of the reference antenna port on both the frequency axis and the time axis), so all measurable statistical characteristics can be referenced on the frequency axis and the time axis.

[0111] QCL-Type B is the QCL type used when the bandwidth of the target antenna port is sufficient to measure measurable statistical characteristics (e.g., Doppler shift and Doppler spread).

[0112] QCL-Type C is the QCL type used when the bandwidth and transmission duration of the target antenna port are not sufficient to measure second-order statistics (e.g., Doppler spread and delay spread), so first-order statistics such as Doppler shift and average delay can be referenced.

[0113] QCL-TypeD is a QCL type that is set when a spatial reception filter value used when receiving through a reference antenna port can be used when receiving through a target antenna port.

[0114] The base station can configure or indicate up to two QCL configurations in one target antenna port through the TCI state configuration as shown in Table A-2 below.

[0115] [Table A-2]

[0116]

[0117] In Table A-2, the tci-StateId field may include a TCI state indicator, the qcl-Type1 field indicates a first QCL configuration for a target antenna port to which a corresponding TCI state is applied, and the qcl-Type2 field indicates a second QCL configuration for a target antenna port to which a corresponding TCI state is applied. Of the two QCL configurations included in one TCI state configuration, the first QCL configuration may be set to one of QCL-TypeA, QCL-TypeB, and QCL-TypeC. In this case, the configurable QCL type is specified according to the types of the target antenna port and the reference antenna port, as described below. Of the two QCL configurations included in one TCI state configuration, the second QCL configuration may be set to QCL-TypeD and may be omitted in some cases. However, this is only one embodiment of the present disclosure, and in some cases, the first QCL configuration and the second QCL configuration may be set to at least one of QCL-type A to QCL-type D.

[0118] The following Tables 4-1 to 4-5 show valid TCI state configurations according to the target antenna port type.

[0119] Table 4-1 shows the valid TCI state configuration when the target antenna port is used for tracking CSI-RS (TRS). TRS refers to non-zero power (NZP) CSI-RS, where no repetition parameter is set between CSI-RS and trs-Info is set to true. Configuration 3 in Table 4-1 can be used for non-periodic TRS.

[0120] [Table 4-1] Valid TCI state configuration when the target antenna port is used for tracking CSI-RS (TRS)

[0121]

[0122] Table 4-2 shows a valid TCI state configuration when the target antenna port is a CSI-RS for CSI. The CSI-RS for CSI refers to an NZP CSI-RS in which a repetition parameter is not set in the CSI-RS and trs-Info is not set to true.

[0123] [Table 4-2] Valid TCI state configuration when the target antenna port is CSI-RS for CSI

[0124]

[0125] Table 4-3 shows the valid TCI state configuration when the target antenna port is a CSI-RS for beam management (BM) (for example, the CSI-RS for BM can have the same meaning as the CSI-RS for L1 RSRP reporting). The CSI-RS for BM refers to the NZP CSI-RS, in which the repetition parameter is set and has a value of On or Off, and trs-Info is not set to true in the CSI-RS.

[0126] [Table 4-3] Valid TCI state configuration when the target antenna port is CSI-RS for BM (for L1 RSRP reporting)

[0127]

[0128] Table 4-4 shows the valid TCI state configuration when the target antenna port is used for the physical downlink control channel (PDCCH) demodulation reference signal (DMRS).

[0129] [Table 4-4] Valid TCI state configuration when the target antenna port is used for PDCCH DMRS

[0130]

[0131] Table 4-5 shows valid TCI state configurations when the target antenna port is used for physical downlink shared channel (PDSCH) DMRS.

[0132] Table 4-5 Valid TCI state configuration when the target antenna port is used for PDSCH DMRS

[0133]

[0134] The representative QCL configuration method according to Tables 4-1 to 4-5 above is to set and operate the target antenna port and reference antenna port of each step as "SSB" -> "TRS" -> "CSI-RS for CSI, or CSI-RS for BM, or PDCCH DMRS, or PDSCH DMRS". This can help the reception operation of the UE, whose statistical characteristics can be measured from the synchronization signal block (SSB) and TRS associated with the antenna port.

[0135] The following describes a method for allocating time and frequency resources for data transmission in an NR communication system.

[0136] In the NR communication system, in addition to the frequency axis resource candidate allocation indicated by BWP, the following frequency domain resource allocation (FD-RA) method can also be provided.

[0137] Figure 6is a diagram illustrating a method of allocating resources on a PDSCH frequency axis in a wireless communication system according to an embodiment of the present disclosure.

[0138] Figure 6 Three frequency axis resource allocation methods of Type 0 and Type 1 configurable via a higher layer and dynamic changes (eg, dynamic switching) are shown.

[0139] Reference Figure 6 , the frequency axis resource allocation method according to type 0 is indicated as RA type 0 (6-00), the frequency axis resource allocation method according to type 1 is indicated as RA type 0 (6-05), and the frequency axis resource allocation method according to dynamic change is indicated as both Ra type 0 and Ra type 1 (6-10).

[0140] Reference Figure 6 If the UE is configured to use only resource type 0 (6-00) through higher layer signaling, some downlink control information (DCI) used to allocate PDSCH to the UE has N RBG The conditions are as follows. In this case, N RBG It refers to the number of resource block groups (RBGs) determined according to the BWP size allocated by the BWP indicator and the higher layer parameter rbg-Size as shown in Table 5 below, and data is transmitted in the RBG, where the value of the corresponding bit in the bitmap is represented as 1.

[0141] [Table 5]

[0142] Bandwidth portion size Configuration 1 Configuration 2 1-36 2 4 37-72 4 8 73-144 8 16 145-275 16 16

[0143] If the UE is configured to use only resource type 1 (6-05) through higher layer signaling, some DCIs of PDSCH allocated to the corresponding UE have the following characteristics: The frequency axis resource allocation information of bits is provided. The conditions are as follows. By doing so, the base station can configure the starting virtual resource block (VRB) 6-20 and the length 6-25 of the frequency axis resources continuously allocated therefrom.

[0144] If the UE is configured to use both resource type 0 and resource type 1 (6-10) through higher layer signaling, some DCIs that allocate PDSCH to the UE have frequency-axis resource allocation information, and the frequency-axis resource allocation information includes a larger bit (6-35) for setting the payload 6-15 of resource type 0 and the payload 6-20 and 6-25 for setting the resource type 1. The conditions are as follows. In this case, a bit (e.g., the most significant bit (MSB)) can be added to a specific part of the frequency-axis resource allocation information in the DCI, such as the front part, and when the corresponding bit is 0, this can indicate the use of resource type 0, and when the corresponding bit is 1, it can indicate the use of resource type 1.

[0145] Figure 7 is a diagram illustrating a method of allocating resources on a PDSCH time axis in a wireless communication system according to an embodiment of the present disclosure.

[0146] Figure 7 An example of timeline resource allocation for PDSCH in an NR communication system is shown.

[0147] Reference Figure 7 The base station can use the subcarrier spacing (SCS) and scheduling offset (K 0 ), the OFDM symbol starting position 7-00 and length 7-05 dynamically indicated by DCI in a time slot are used to indicate the position of the PDSCH resource on the time axis (where the subcarrier spacing of the data channel is μ PDSCH , the subcarrier spacing of the control channel is μ PDCCH ).

[0148] Figure 8 is a diagram illustrating a method of allocating resources on a time axis according to subcarrier spacings of a data channel and a control channel in a wireless communication system according to an embodiment of the present disclosure.

[0149] Reference Figure 8 , it can be determined that when the subcarrier spacing of the data channel and the control channel is the same (8-00), for example, when μ PDSCH =μ PDCCH At (8-00), the number of time slots of the data channel is the same as the number of time slots of the control channel, so the base station and the UE generate a scheduling offset to adapt to the predetermined time slot offset K 0 In contrast, it can be determined that when the subcarrier spacings of the data channel and the control channel are different from each other (8-05), for example, when μ PDSCH ≠μ PDCCH(8-05), the number of time slots of the data channel is different from the number of time slots of the control channel, so the base station and the UE generate a scheduling offset relative to the subcarrier spacing of the PDCCH to adapt to the predetermined time slot offset K 0 .

[0150] According to the purpose of efficient control channel signal reception by the UE, the NR communication system provides various types of DCI formats as shown in Table 6 below.

[0151] [Table 6]

[0152]

[0153] For example, the base station may use DCI format 0_0 or DCI format 0_1 ​​to allocate, eg, schedule, a PDSCH to a cell.

[0154] When DCI format 0_1 ​​is transmitted with a CRC scrambled by a cell radio network temporary identifier (C-RNTI), a configured scheduling RNTI (CS-RNTI) or a new RNTI (new-RNTI), DCI format 0_1 ​​includes, at least, the following information such as an information field.

[0155] - Identifier of DCI format (1 bit) field: The identifier of DCI format field is a DCI format indicator and may always be set to 1.

[0156] - Frequency domain resource allocation (N RBG Bit or bit) field: The frequency domain resource allocation field indicates the frequency axis resource allocation, and when monitoring DCI format 1_0 in the UE-specific search space, is the size of the activated DL BWP. When DCI format 1_0 is not monitored in the UE-specific search space, is the size of the initial DL BWP. N RBG is the number of the resource block group. This method refers to frequency axis resource allocation.

[0157] -Time Domain Resource Allocation (0 to 4 bits) field: The Time Domain Resource Allocation field indicates the time axis resource allocation according to the above description.

[0158] - VRB-to-PRB mapping (1 bit) field: If the value of the VRB-to-PRB mapping field is 0, it indicates non-interleaved VRP to PRB mapping. If the value of the VRB-to-PRB mapping field is 1, it indicates interleaved VRP to PRB mapping.

[0159] - Modulation and Coding Scheme (5 bits) field: The Modulation and Coding Scheme field indicates the modulation order and coding rate used for PDSCH transmission.

[0160] - New Data Indicator (1 bit) field: The New Data Indicator field indicates whether the PDSCH is initial transmission or retransmission according to whether it is switched.

[0161] - Redundancy Version (2 bits) field: The Redundancy Version field indicates the redundancy version used for PDSCH transmission.

[0162] - HARQ process number (4 bits) field: The HARQ process number field indicates the Hybrid Automatic Repeat Request (HARQ) process number used for PDSCH transmission.

[0163] - Downlink Allocation Index (2 bits) field: The Downlink Allocation Index field is a DAI indicator.

[0164] - TPC Command for Scheduled PUCCH (2 bits) field: The TPC Command for Scheduled PUCCH field is a PUCCH power control indicator.

[0165] - PUCCH Resource Indicator (3 bits) field: The PUCCH Resource Indicator field is a PUCCH resource indicator and indicates one of eight resources configured by a higher layer.

[0166] - PDSCH-to-HARQ_feedback timing indicator (3 bits) field: The PDSCH-to-HARQ_feedback timing indicator field is a HARQ feedback timing indicator and indicates one of eight feedback timing offsets set by a higher layer.

[0167] When DCI format 1_1 is transmitted together with a CRC scrambled by a cell radio network temporary identifier (C-RNTI), a configured scheduling RNTI (CS-RNTI), or a new RNTI, DCI format 1_1 includes at least the following information, such as an information field.

[0168] - Identifier of DCI format (1 bit) field: The identifier of DCI format field is a DCI format indicator and may always be set to 1.

[0169] - Carrier indicator (0 or 3 bits) field: The carrier indicator field indicates the component carrier (CC) (or cell) on which the PDSCH allocated by the corresponding DCI is transmitted.

[0170] - Bandwidth Part Indicator (0 or 1 or 2 bits) field: The Bandwidth Part Indicator field indicates the BWP in which the PDSCH allocated by the corresponding DCI is transmitted.

[0171] - Frequency Domain Resource Allocation (Payload Determined Based on Frequency Axis Resource Allocation) Field: The Frequency Domain Resource Allocation field indicates the frequency axis resource allocation, and is the size of the activated DL BWP. Since this method has been described in the frequency axis resource allocation, it will not be repeated below.

[0172] - Time Domain Resource Allocation (0 to 4 bits) field: The Time Domain Resource Allocation field indicates the time axis resource allocation according to the above description.

[0173] - VRB-to-PRB Mapping (0 or 1 bit) field: If the value of the VRB-to-PRB Mapping field is 0, it indicates non-interleaved VRP to PRB mapping, and if the value of the VRB-to-PRB Mapping field is 1, it indicates interleaved VRP to PRB mapping. When the frequency axis resource allocation is set to resource type 0, the number of bits of the VRB-to-PRB Mapping field is 0.

[0174] -PRB bundling size indicator (0 or 1 bit) field: If the higher layer parameter prb-BundlingType is not set or the value of prb-BundlingType is set to "static", the number of bits in the PRB bundling size indicator field is 0, if the value of prb-BundlingType is set to "dynamic", the number of bits in the PRB bundling size indicator field is 1.

[0175] - Rate Matching Indicator (0 or 1 or 2 bits) field: The Rate Matching Indicator field indicates the rate matching mode.

[0176] - ZP CSI-RS Trigger (0 or 1 or 2 bits) field: The ZP CSI-RS Trigger field is an indicator for triggering aperiodic ZP CSI-RS.

[0177] -For transport block 1:

[0178] - Modulation and Coding Scheme (5 bits) field: The Modulation and Coding Scheme field indicates the modulation order and coding rate used for PDSCH transmission.

[0179] - New Data Indicator (1 bit) field: The New Data Indicator field indicates whether the PDSCH is initial transmission or retransmission according to whether it is switched.

[0180] - Redundancy Version (2 bits) field: The Redundancy Version field indicates the redundancy version used for PDSCH transmission.

[0181] -For transport block 2:

[0182] - Modulation and Coding Scheme (5 bits) field: The Modulation and Coding Scheme field indicates the modulation order and coding rate used for PDSCH transmission.

[0183] - New Data Indicator (1 bit) field: The New Data Indicator field indicates whether the PDSCH is initial transmission or retransmission according to whether it is switched.

[0184] - Redundancy Version (2 bits) field: The Redundancy Version field indicates the redundancy version used for PDSCH transmission.

[0185] -HARQ process number (4 bits) field: The HARQ process number field indicates the HARQ process number used for PDSCH transmission.

[0186] - Downlink Allocation Index (0 or 2 or 4 bits) field: The Downlink Allocation Index field is a DAI indicator.

[0187] - TPC Command for PUCCH for Scheduling (2 bits) field: The TPC Command for PUCCH for Scheduling field is a PUCCH power control indicator.

[0188] - PUCCH Resource Indicator (3 bits) field: The PUCCH Resource Indicator field is a PUCCH resource indicator and indicates one of eight resources configured by a higher layer.

[0189] - PDSCH-to-HARQ_feedback timing indicator (3 bits) field: The PDSCH-to-HARQ_feedback timing indicator field is a HARQ feedback timing indicator and indicates one of eight feedback timing offsets set by a higher layer.

[0190] - Antenna Port (4 or 5 or 6 bits) field: The Antenna Port field indicates a DMRS port and a code division multiplexing (CDM) group without data.

[0191] -Transmission Configuration Indication (0 or 3 bits) field: The Transmission Configuration Indication field indicates the TCI indicator.

[0192] - SRS request (2 or 3 bits) field: The SRS request field indicates a sounding reference signal (SRS) transmission request indicator.

[0193] -CBG transmission information (0 or 2 or 4 or 6 or 8 bits) field: The CBG transmission information field is an indicator indicating whether a code block group is transmitted in the allocated PDSCH. When the value of the CBG transmission information field is 0, it indicates that the corresponding code block group (CBG) is not transmitted, and when the value of the CBG transmission information field is 1, it indicates that the corresponding CBG is transmitted.

[0194] -CBG Clear Information (0 or 1 bit) field: The CBG Clear Information field is an indicator of whether the previous CBG is corrupted. If the value of the CBG Clear Information field is 0, it means that the previous CBG may have been corrupted. If the value of the CBG Clear Information field is 1, it means that the previous CBG will be used (can be combined) when a retransmission is received.

[0195] -DMRS Sequence Initialization (0 or 1 bit) field: The DMRS Sequence Initialization field is a DMRS scrambling ID selection indicator.

[0196] The maximum number of DCIs of different sizes that the UE can receive in each time slot in the corresponding cell is 4. The maximum number of DCIs of different sizes scrambled with a cell radio network temporary identifier (C-RNTI) that the UE can receive in each time slot in the corresponding cell is 3.

[0197] Here, the antenna port indication may be represented by the following Tables 7 to 10.

[0198] [Table 7] Antenna port (1000+DMRS port), dmrs-Type=1, maxLength=1

[0199]

[0200] [Table 8] Antenna port (1000+DMRS port), dmrs-Type=1, maxLength=2

[0201]

[0202] [Table 9] Antenna port (1000+DMRS port), dmrs-Type=2, maxLength=1

[0203]

[0204] [Table 10] Antenna port (1000+DMRS port), dmrs-Type=2, maxLength=2

[0205]

[0206]

[0207]

[0208] Table 7 is a table used when dmrs-type is 1 and maxLength is 1. Table 8 is a table used when dmrs-Type=1 and maxLength=2. When dmrs-type=2 and maxLength=1, Table 9 is used, and when drms-tpye is 2 and maxLength is 2, Table 10 is used to indicate the port of DMRS. In Tables 7 to 10, the numbers 1, 2, and 3 indicated by the number of the DMRS CDM group without data are the CDMR groups {0}, {0, 1}, and {0, 1, 2}, respectively. The DMRS port is a sequence of port indexes to be used. The antenna port is indicated as DMRS port + 1000. The CDM group of DMRS is connected to the method for generating a DMRS sequence, and the antenna port is as shown in Tables 11 and 12. Table 11 shows the parameters when dmrs-type=1 is used, and Table 12 shows the parameters when dmrs-type=2 is used.

[0209] [Table 11] Parameters for PDSCH DMRS dmrs-type=1

[0210]

[0211] [Table 12] Parameters of PDSCH DMRS dmrs-type=2

[0212]

[0213] A DMRS sequence according to each parameter is determined by Equation 1 below.

[0214] [Equation 1]

[0215]

[0216]

[0217] k'=0,1

[0218]

[0219] n=0,1,...

[0220] In Tables 7 and 8, when only one codeword is enabled, rows 2, 9, 10, 11, and 30 are only used for single-user multiple-input multiple-output (MIMO). That is, in this case, the UE may not perform multi-user MIMO reception operations, such as eliminating, nulling, or whitening multi-user interference, without assuming that other UEs are co-scheduled.

[0221] In Tables 9 and 10, rows 2, 10, and 23 are used only for single-user MIMO when only one codeword is enabled. That is, in this case, the UE does not perform multi-user MIMO reception operations, such as canceling, nulling, or whitening multi-user interference, without assuming that other UEs are co-scheduled.

[0222] Fig. 9 is a diagram showing a cooperative communication antenna port configuration according to an embodiment of the present disclosure.

[0223] Fig. 9 An example of radio resource allocation for each transmission and reception point (TRP) according to the context and the joint transmission (JT) scheme is shown.

[0224] Reference Fig. 9 , 9-00 shows an example of coherent joint transmission (C-JT) supporting interferometric coding between each cell, TRP and / or beam.

[0225] In C-JT, the same data (e.g., PDSCH signal) is transmitted in TRP A 9-05 and TRP B 9-10, and joint precoding is performed in multiple TRPs. This may mean that in TRP A 9-05 and TRP B 9-10, the same DMRS port (e.g., DMRS ports A and B in both TRPs) is used for the same PDSCH signal transmission. In this case, UE9-15 can receive a DCI format for receiving a PDSCH signal demodulated based on the DMRS sent through DMRS ports A and B.

[0226] Reference Fig. 9 , 9-20 shows an example of non-coherent joint transmission (NC-JT) that supports non-coherent precoding between each cell, TRP and / or beam. In the case of NC-JT, different PDSCH signals are transmitted in each cell, TRP and / or beam, and separate precoding can be applied to each PDSCH signal. This may mean that TRP A 9-25 and TRPB 9-30 use different DMRS ports (e.g., DMRS port A in TRP A and DMRS port B in TRP B) for different PDSCH signal transmissions. In this case, UE 9-35 can receive two DCI formats for receiving PDSCH signal A demodulated based on DMRS sent through DMRS port A and PDSCH signal B demodulated based on DMRS sent through DMRS port B.

[0227] In order to support NC-JT to provide data for one UE at two or more transmission points at the same time, it may be necessary to allocate PDSCHs transmitted through a single PDCCH from two (or more) different transmission points or allocate PDSCHs transmitted through multiple PDCCHs from two (or more) transmission points. The UE can obtain a quasi-co-location (QCL) connection relationship between channels or various reference signals based on L1 / L2 / L3 signaling, and can effectively estimate large-scale parameters of various reference signals or channels based on the obtained QCL connection relationship.

[0228] If the transmission points of a specific reference signal or channel are different, it may be difficult to share large-scale parameters. Therefore, when performing joint transmission, the base station needs to provide the UE with quasi-co-location information of two or more transmission points through two or more TCI states at the same time. If non-coherent joint transmission is supported through multiple PDCCHs, that is, if two or more PDSCHs are simultaneously allocated to the same service cell and the same bandwidth part through two or more PDCCHs, two or more TCI states can be separately allocated to PDSCH or DMRS ports through PDCCH. On the other hand, if non-coherent joint transmission is supported through a single PDCCH, that is, if two or more PDSCHs are simultaneously allocated to the same service cell and the same bandwidth part through one PDCCH, two or more TCI states need to be allocated to PDSCH or DMRS ports through one PDCCH.

[0229] Assuming that the DMRS ports allocated to the UE at a specific time are divided into DMRS port group A transmitted from transmission point A and DMRS port group B transmitted from transmission point B, two or more TCI states can be separately connected to the DMRS port groups, so that the channel can be estimated based on each group of different QCL assumptions.

[0230] Different DMRS ports can be code division multiplexed (CDM), frequency division multiplexed (FDM) or time domain multiplexed (TDM) to improve channel measurement accuracy and reduce transmission load. When the DMRS ports processed by CDM are collectively referred to as CDM groups, when each port has similar channel characteristics, the DMRS ports in the CDM group work well on coding-based multiplexing (that is, when each port has similar characteristics, it can be well divided by orthogonal cover codes (OCC)). Therefore, it may be of great significance to avoid DMRS ports in the same CDM group having different TCI states. According to an embodiment of the present disclosure, a method is provided to indicate to a UE that there is no data on the DMRS port and CDM group to meet the characteristics.

[0231] For convenience of description, a process of transmitting control information via a PDCCH may be referred to as sending a PDCCH, and a process of transmitting data via a PDSCH may be referred to as sending a PDSCH.

[0232] Hereinafter, for the convenience of description, Tables 7 to 12 are referred to as "first antenna port indication" (or "antenna port indication according to the related art"), and the table obtained after modifying all or part of the code points in Tables 7 to 12 is referred to as "second antenna port indication" (or "new antenna port indication"). DMRS ports and CDM groups without data allocation are referred to as DMRS allocation.

[0233] The UE can determine the number of antenna ports used when sending PDSCH by indicating the table of DMRS ports. In the antenna port indication method based on Rel-15, DCI format 1_1 can be based on an index of 4 bits to 6 bits in length indicated in the antenna port field in the DCI, and the antenna port can be determined accordingly. The UE can identify the number and index of the DMRS port of the PDSCH, the number of the front load symbol, and the number of the CDM group based on the indicator (index) sent by the base station. The UE can determine the dynamic change of the beamforming direction based on the information about the transmission configuration indication (TCI) in DCI 1_1.

[0234] If the tci-PresentDCI field is set to "enabled" in the higher layer, the UE can identify the TCI field of 3 bits of information in the scheduled component carrier or DL ​​BWP and determine the beam direction associated with the downlink reference signal (DL-RS) and the activated TCI state. Conversely, if the tci-PresentDCI field is deactivated, it can be considered that the beam direction of the beamforming has not changed.

[0235] According to an embodiment of the present disclosure, a scenario in which a PDSCH transmitted from two (or more) different transmission points is allocated through a single PDCCH is considered. The Rel-15 UE receives a single-layer or multi-layer PDSCH stream including QCL based on the antenna port information and TCI information in a single PDCCH. The Rel-16 UE can receive data from multiple base stations or multiple TRPs in the form of C-JT / NC-JT. In order to support C-JT / NC-JT, the Rel-16 UE requires a default high-level configuration. Specifically, for the high-level configuration, the UE needs to receive C-JT / NC-JT related parameters or setting values ​​and configure them.

[0236] Example 1

[0237] In the present disclosure, a separate DMRS port table is proposed for base stations and UEs supporting C-JT / NC-JT, and the DMRS port table is used to send and receive C-JT / NC-JT transmission signaling. The proposed DMRS port table can be generated as a separate table from the DMRS port table indicated by the antenna port field based on DCI format 1_1. As a method of distinguishing from the DMRS port table proposed in Rel-15, the base station and the UE can pre-configure information about whether NC-JT transmission is supported in the RRC configuration. That is, fields such as C-JT / NC-JT transmission = enable / disable, and whether to identify C-JT / NC-JT based on the C-JT / NC-JT transmission field can be set through the RRC configuration.

[0238] When the field value of the C-JT / NC-JT transmission field is set to enabled by a higher layer (C-JT / NC-JT transmission = enabled), the antenna port field of the existing DCI format 1_1 can be used to indicate the field that the UE should use. Alternatively, a separate field can be used to indicate at least one of the DMRS port number for NC-JT transmission, the number of DMRS CDM groups without data, the (maximum) number of front load symbols, and the DMRS type, but the antenna port field is formed in a separate DCI format 1_1.

[0239] Tables 12-1 to 12-4 propose DMRS ports so that DMRS ports transmitted in the same TRP are transmitted to the same CDM group relative to the above-mentioned CDM group associated with Table 11. In Tables 12-1 to 12-4, different TRP transmissions and different CDM group mappings are distinguished by a semicolon (;) between the left and right sides, but may also be omitted depending on the embodiment. In addition, the order of the values ​​included in the table may be changed based on the semicolon (;). In addition, the DMRS ports described in conjunction with Tables 12-1 to 12-4 show an example in which the first TRP and the second TRP each support up to two DMRS ports. In addition, the basic concepts of DMRS ports, types, and numbering of front load symbols described above in conjunction with Tables 12-1 to 12-4 and Tables 7 to 10 may be similarly applied.

[0240] As shown in Table 12-1, the DMRS port table for C-JT / NC-JT purposes can support other types of ports, which is different from the ports not supported in Rel-15.

[0241] For example, if the base station indicates entry 0 (or also referred to as value) to the UE, the UE can determine that the first TRP and the second TRP send DMRS via DMRS port 0 and DMRS port 2. When identifying that the number of the DMRS port of each TRP is 1, the UE can determine to perform single-layer transmission from the first TRP and the second TRP.

[0242] If the base station indicates entry 1 to the UE, the UE can determine that the first TRP and the second TRP send DMRS via DMRS port 1 and DMRS port 3. When it is identified that the DMRS port number of each TRP is 1, the UE can determine to perform single-layer transmission from the first TRP and the second TRP. Although the DMRS port number in entry 1 is different from the DMRS port number in entry 0, the function of entry 1 is similar to that of entry 0. Therefore, entry 1 can be regarded as overlapping with entry 0 and can be omitted from Table 12-1 above.

[0243] If the base station indicates entry 2 to the UE, the UE can determine that the first TRP sends DMRS via DMRS port 0 and DMRS port 1, and the second TRP sends DMRS via DMRS port 2. When identifying that the DMRS port number of the first TRP is 2 and the DMRS port number of the second TRP is 1, the UE can determine to perform layer 2 transmission in the first TRP when the second TRP performs layer 1 transmission.

[0244] If the base station indicates item 3 to the UE, the UE can determine that the first TRP sends DMRS via DMRS port 0, and the remaining TRP (i.e., the second TRP) sends DMRS via DMRS port 2 and DMRS port 3. When it is identified that the DMRS port number of the first TRP is 1 and the DMRS port number of the second TRP is 2, the UE can determine that a single-layer transmission is performed in the first TRP when a two-layer transmission is performed in the second TRP.

[0245] The operations of the base station and the UE for items 4 and 5 can be easily understood from the description given above in conjunction with items 2 and 3. Although the DMRS port numbers of items 4 and 5 are different from those of items 2 and 3, they are similar in function and thus can be omitted from the above table.

[0246] If the base station indicates item 6 to the UE, the UE can determine that the first TRP sends DMRS via DMRS port 0 and DMRS port 1, and the other TRP (i.e., the second TRP) sends DMRS via DMRS port 2 and DMRS port 3. When it is identified that the port number of each of the first TRP and the second TRP is 2, the UE can determine that 2-layer transmission is performed in the first TRP when 2-layer transmission is performed in the second TRP.

[0247] Table 12-1 shows various scenario examples of communication between a base station and a UE in the form of entries, and all or part of the 7 entries can be applied to an actual system. In addition, a different table configured with at least one of the entries included in the above Table 12-1 can be used. Table 12-1 shows an example of a base station sending a codeword to a UE. However, even when the base station sends two or more codewords to the UE, a method similar to the method shown in Table 12-1 can be applied.

[0248] Table 12-2 shows an example in which, in the same DMRS type as the DMRS type described above in conjunction with Table 12-1 (e.g., DMRS type 1), for example, when maxLength is 2 (maxLength=2), maxLength is different from the maxLength described above in conjunction with Table 12-1. Referring to Tables 7 and 8, the DMRS port configuration of C-JT / NC-JT can be mapped from DMRS port 0 to DMRS port 3 in the same manner as when maxLength is 1 (maxLength=1).

[0249] Table 12-3 is a DMRS port table for C-JT / NC-JT transmission of a DMRS type (e.g., DMRS type 2) different from the DMRS type (e.g., DMRS type 1) described above in conjunction with Table 12-1. Table 12-3 supports up to 12 DMRS ports, which is a structure suitable for MU-MIMO.

[0250] For example, if the base station indicates entry 1 to the UE, the UE can determine that both the first TRP and the second TRP send DMRS via DMRS port 0 and DMRS port 2. When it is identified that the DMRS port number of each of the first TRP and the second TRP is 1, the UE can determine that single-layer transmission is performed from the first TRP and the second TRP, respectively. The entries in Table 12-3 represent the case where the number of DMRS CDM groups is 2 and the case where the number of DMRS CDM groups is 3, but do not exclude the case where the number of DMRS CDM groups is 2 and the case where the number of DMRS CDM groups is 3, which are shown separately from each other in the entries. The above embodiment shows a list in the form of entries, and all or part of the 14 entries can be applied to an actual system.

[0251] For example, some of the 14 entries may be entries 0, 2, 3, 6, 7, 9, 10, and 13, and the table may be determined based on entries 0, 2, 3, 6, 7, 9, 10, and 13. The order of entries in the above embodiment is only one embodiment, and the embodiments of the present disclosure are not limited thereto. Table 12-3 shows an example of a base station sending a codeword to a UE. However, the case where the base station sends two or more codewords to the UE may also be similar to the case where the base station sends one codeword to the UE.

[0252] Table 12-4 shows an example in which, in the same DMRS type as the DMRS type described above in conjunction with Table 12-3 (e.g., DMRS type 2), for example, when maxLength is 2 (maxLength=2), maxLength is different from the maxLength described above in conjunction with Table 12-3. Referring to Tables 7 and 8, a total of 2 to 4 DMRS ports are allocated in the DMRS port configuration of C-JT / NC-JT, and at least one DMRS port is allocated to each CDM group. According to the number of front load symbols, if the number of front load symbols is 1, at least one DMRS port of each CDM group is allocated to DMRS ports 0 to 3 (described above in conjunction with Table 12-3, and will not be repeated below), and if the number of front load symbols is 2, at least one DMRS port of each CDM group is allocated to DMRS ports 0 to 7. When a total of 2 DMRS ports are used for each CDM group, the frequency domain orthogonal cover code (OCC) of each CDM group should be the same.

[0253] At the same time, the time domain OCC of each CDM group can be the same or different. For example, in CDM group {0,1}, DMRS ports 0 and 2 using the same time domain OCC can be used simultaneously, and DMRS ports 0 and 6 using different time domain OCCs can also be used simultaneously. When three or more DMRS ports are used, the time domain OCC applied to CDM group {0,1} can be the same or different. The above embodiments are listed in the form of items, and all or part of the 28 items can be applied to actual systems.

[0254] For example, some entries may be entries 0, 2, 3, 6, 7, 9, 10, and 13 or 0, 2, 3, 6, 7, 9, 10, 13, 14, 16, 17, 20, 23, 24, and 27, and the table may be determined based on entries 0, 2, 3, 6, 7, 9, 10, and 13 or 0, 2, 3, 6, 7, 9, 10, 13, 14, 16, 17, 20, 23, 24, and 27. The order of entries in the above embodiment is only one embodiment, and the embodiments of the present disclosure are not limited thereto. Table 12-4 shows an example of a base station sending a codeword to a UE. However, the case where the base station sends two or more codewords to the UE may be similar to those described above in conjunction with Table 12-4.

[0255] [Table 12-1] DMRS indication table of antenna port (1000+DMRS port),

[0256] dmrs-Type=1, maxLength=1

[0257]

[0258] [Table 12-2] DMRS indication table for antenna port (1000+DMRS port), dmrs-Type=1, maxLength=2

[0259]

[0260] [Table 12-3] DMRS indication table for antenna port (1000+DMRS port), dmrs-Type=2, maxLength=1

[0261]

[0262] [Table 12-4] DMRS indication table for antenna port (1000+DMRS port), dmrs-Type=2, maxLength=2

[0263]

[0264] Example 2

[0265] Table 13-1 proposes a method of using code points of reserved bits in Rel-15 as a method for the base station to indicate the DMRS port to the UE for C-JT / NC-JT transmission. As shown in Table 7, in the Rel-15 DMRS port table, bits 0 to 11 are used, but bits 12 to 15 as reserved bits are not used. According to an embodiment of the present disclosure, as shown in Table 13-1, 4 code points 12 to 15 in the DMRS port table can be used to indicate the DMRS port for joint transmission in two TRPs. Therefore, the use of reserved bits can eliminate the need for the base station to allocate a separate field to the UE, thereby more efficiently utilizing DCI resources.

[0266] For example, when the base station indicates entry 12 to the UE, the UE can determine that the first TRP and the second TRP send DMRS via DMRS port 0 and DMRS port 2. When identifying that the DMRS port number used in each TRP is 1, the UE can determine to perform single-layer transmission from each of the first TRP and the second TRP.

[0267] As another example, if the base station indicates item 13 to the UE, the UE can determine that the first TRP sends DMRS via DMRS port 0 and DMRS port 1, and the second TRP sends DMRS via DMRS port 2. When identifying that the DMRS port number used in the first TRP is 2 and the DMRS port number used in the second TRP is 1, the UE can determine that 2-layer transmission is performed in the first TRP when 1-layer transmission is performed in the second TRP.

[0268] As another example, if the base station indicates item 14 to the UE, the UE can determine that the first TRP transmits DMRS via DMRS port 0, and the remaining one TRP (i.e., the second TRP) transmits DMRS via DMRS port 2 and DMRS port 3. When identifying that the DMRS port number used in the first TRP is 1 and the DMRS port number used in the second TRP is 2, the UE can determine that single-layer transmission is performed in the first TRP when 2-layer transmission is performed in the second TRP.

[0269] As another example, if the base station indicates entry 15 to the UE, the UE can determine that the first TRP transmits DMRS via DMRS port 0 and DMRS port 1, and another TRP (i.e., the second TRP) transmits DMRS via DMRS port 2 and DMRS port 3. When it is identified that the port number used by the first TRP and the second TRP is respectively 2, the UE can determine that 2-layer transmission is performed in the first TRP when 2-layer transmission is performed in the second TRP.

[0270] Here, a UE in which the field value of the C-JT / NC-JT transmission field is set to enabled by a high layer (C-JT / NC-JT transmission = enabled) can identify the remaining code points of the existing antenna port field in DCI format 1_1 and dynamically determine whether to perform C-JT / NC-JT transmission. That is, when the antenna port field in DCI format 1_1 is 12 to 15, the UE can identify the number of TRPs, the number of transmission layers, the number of DMRS CDM groups without data, and the number of front load symbols used to transmit the PDSCH scheduled in the DCI. The above embodiment shows a list in the form of entries, and all or part of the 4 entries can be applied to an actual system. The order of entries in the above embodiment is only one embodiment, and the embodiments of the present disclosure are not limited to this.

[0271] As an example, Tables 13-2 to 13-4 are embodiments obtained by adding some DMRS ports generated separately in Tables 12-2 to 12-4 to Tables 8 to 10 defined in the Rel-15 standard. Duplicate DMRS ports are omitted in Tables 13-2 to 13-4 to minimize the bit size. The omission is only an embodiment, and all or part of the DMRS ports shown in Tables 12-1 to 12-4 may be used additionally. The base station may schedule joint transmission of the same DMRS port as shown in Tables 12-1 to 13-4 for Rel-16 NC-JT UEs, schedule single-port transmission for Rel-15 UEs, and perform downlink MU-MIMO operations.

[0272] As another example, if some entries in Tables 13-1 to 13-4 have the same DMRS port index, the duplicate index can be omitted. That is, in Table 13-1, the DMRS port index of entries 12, 13, and 15 for NC-JT transmission is the same as the DMRS port index of entries 11, 9, and 10, and the DMRS port index of entries 12, 13, and 15 can be omitted. In Table 13-2, the DMRS port index of entries 31, 32, and 34 for NC-JT transmission is the same as the DMRS port index of entries 11, 9, and 10, and the DMRS port index of entries 31, 32, and 34 can be omitted. In Table 13-3, the DMRS port index of entries 24, 25, 27, 29, and 31 for NC-JT transmission is the same as the DMRS port index of entries 23, 9, 10, 29, and 22, and the DMRS port index of entries 24, 25, 27, 29, and 31 can be omitted. In Table 13-3, the DMRS port indexes of entries 24, 25, 27, 29, and 31 for NC-JT transmission are the same as the DMRS port indexes of entries 23, 9, 10, 29, and 22, and the DMRS port indexes of entries 24, 25, 27, 29, and 31 may be omitted. In Table 13-4, the DMRS port indexes of entries 58, 59, 61, 63, and 65 for NC-JT transmission are the same as the DMRS port indexes of entries 23, 9, 10, 20, and 22, and the DMRS port indexes of entries 58, 59, 61, 63, and 65 may be omitted. The DMRS port index can be omitted based on at least one of the following: assuming that at least different CDM groups used for NC-JT are not transmitted in the same DMRS port, assuming that the TCI field can indicate whether NC-JT is performed to allow the UE to identify the DMRS port used for NC-JT, and assuming that the UE can distinguish the DMRS ports based on the reception of DCI and the reception of MAC CE messages, so the DMRS port index of the duplicate entries can be omitted.

[0273] [Table 13-1] DMRS indication table for antenna port (1000+DMRS port), dmrs-Type=1, maxLength=1

[0274]

[0275] [Table 13-2] DMRS indication table for antenna port (1000+DMRS port), dmrs-Type=1, maxLength=2

[0276]

[0277] [Table 13-3] DMRS indication table for antenna port (1000+DMRS port), dmrs-Type=2, maxLength=1

[0278]

[0279] [Table 13-4] DMRS indication table for antenna port (1000+DMRS port), dmrs-Type=2, maxLength=2

[0280]

[0281]

[0282]

[0283] According to an embodiment of the present disclosure, a UE may support data from multiple base stations or multiple TRPs in the form of C-JT / NC-JT. A UE supporting C-JT / NC-JT may receive, for example, C-JT / NC-JT related parameters or setting values ​​in a high-level configuration, and set the UE's RRC parameters based on this. For high-level configuration, the UE may utilize the UE capability parameter tci-StatePDSCH. Here, the UE capability parameter tci-StatePDSCH defines the TCI state for PDSCH transmission purposes, and the number of TCI states may be 4, 8, 16, 32, 64, or 128 in FR1, and 64 or 128 in FR2, and a maximum of 8 states that can be represented by 3 bits of the TCI field of the DCI can be set in the set number through the MAC CE information. The maximum value of 128 represents the value indicated by the maxNumberConfiguredTCIstatesPerCC field in the tci-StatePDSCH parameter included in the UE capability signaling. In this way, a series of configuration processing from high-level configuration to MAC CE configuration can be applied to beamforming indication or beamforming change instructions for at least one PDSCH in a TRP.

[0284] According to an embodiment of the present disclosure, how the UE is activated or deactivated by the base station through different MAC CE signaling is described in Rel-15 and Rel-16. Specifically, when allocating PDSCH for a specific UE, such as DCI format 1_1, the TCI field can be used to dynamically support beamforming direction indication or beamforming direction change indication.

[0285] A beamforming direction indication or a beamforming direction change indication refers to an operation applied when a UE that recognizes the TCI status field of DCI format 1_1 receives a PDSCH on the downlink after a predetermined time, and the beamforming direction refers to the corresponding beamforming setting direction associated with the DL RS of the base station / TRP of the QCL.

[0286] First, the base station or UE may determine to use the Rel-15 MAC CE for the Rel-15 DCI format and the Rel-16 MAC CE for the Rel-16 DCI format. Therefore, different solutions are proposed according to the Rel-15 MAC CE structure and the Rel-16 MAC CE structure.

[0287] Fig. 10A is a diagram schematically showing a MAC CE structure for TCI state activation of a UE-specific PDCCH in a wireless communication system according to an embodiment of the present disclosure.

[0288] Reference Fig. 10A , Fig. 10A 10-00 indicates the structure of MAC CE for TCI state activation of UE-specific PDCCH based on Rel-15.

[0289] The meaning of each field in MAC CE and the values ​​that can be set in each field are shown in Table B-1.

[0290] [Table B-1]

[0291]

[0292] Fig. 10A 10-50 indicate the structure of MAC-CE for TCI state activation / deactivation of UE-specific PDSCH based on Rel-15.

[0293] The meaning of each field in MAC CE and the values ​​that can be set in each field are shown in Table B-2.

[0294] [Table B-2]

[0295]

[0296] The MAC CE of Rel-16 can be configured in the form of an extended MAC CE message of Rel-15. In this embodiment of the present disclosure, all TCI states activated by the Rel-15 MAC CE can be included in the TCI state activated by the Rel-16 MAC CE. This will be referred to below. Fig. 10B Give a description.

[0297] Fig. 10B is a diagram illustrating TCI state configuration and beamforming indication operation according to an embodiment of the present disclosure.

[0298] Reference Fig. 10B The base station can determine that all TCI states of the TCI state 10-01 configured by the RRC of Rel-15 include M TCI states, such as TCI#0, TCI#1, TCI#2, ..., TCI#M-1, and select TCI#0', TCI#1', TCI#2', ..., TCI#K-1 from the M TCI states as the subset 10-21 of the TCI state selected by the MAC CE of Rel-15.

[0299] In contrast, base stations and UEs supporting Rel-16 can respectively set the TCI states configured by the RRC supporting Rel-16, or directly use the TCI states configured by the RRC set in Rel-15. In this case, the TCI states configured by the RRC supporting Rel-16 can include some or all of the TCI states configured by the RRC set in Rel-15. If M=128, the number of TCI states for Rel-16 can be equal to or greater than 128. If the base station or UE increases the number of TCI states supported by Rel-15 according to the ratio of the number of base stations / TRPs operating as C-JT / NC-JT in Rel-16, and there are two TRPs running, a maximum of 256 TCI states can be set. Here, in the TCI states configured by the RRC for use by Rel-16, the Rel-16 MAC CE can include some or all of the TCI states supported by the MAC CE of Rel-15. Specifically, if the Rel-16 MAC CE includes all TCI states supported by the MAC CE of Rel-15, and the number of TCI states increases proportionally with the number of base stations / TRPs operating as C-JT / NC-JT in Rel-16, and if there are two TRPs operating, a maximum of 2K TCI states can be set.

[0300] Table 14 shows the details of the above tci-StatePDSCH parameters in combination with the above embodiments. Specifically, the FR2 mandatory value of the parameter maxNumberConfiguredTCIstatesPerCC can be modified from 64 to 128 or 256, or can be increased by 64, 128 or 256 separately for C-JT / NC-JT.

[0301] [Table 14]

[0302]

[0303]

[0304] For example, a base station or UE supporting Rel-15 and Rel-16 may set a maximum value for each of Rel-15 and Rel-16 for setting the TCI state through MAC CE, and set the number of TCI states to a value equal to or less than the set maximum value. The following various embodiments may be proposed as a method for setting the number of TCI states to a value equal to or less than the maximum value.

[0305] The number of TCI states activated by the MAC CE messages of Rel-15 and Rel-16 may be set by the UE capability value reported by the UE. As another example, the number of TCI states activated by the MAC CE messages of Rel-15 and Rel-16 may be determined as a value preset by the base station. As another example, the number of TCI states activated by the MAC CE messages of Rel-15 and Rel-16 may be determined as a value pre-agreed between the base station and the UE.

[0306] As an example, Fig. 10B As shown, the base station and the UE can determine that all TCI states of the TCI state 10-01 configured by the RRC of Rel-15 include M TCI states, such as TCI#0, TCI#1, TCI#2, ..., TCI#M-1, and select TCI#0', TCI#1, TCI#2', ..., TCI#K-1 as a subset 10-21 of the TCI state selected by the MAC CE of Rel-15 from the M TCI states. If TCI#0 is selected from the M TCI states, TCI#0 can be placed on TCI#0'. Here, as an example, the maximum value of K for the base station and UE supporting Rel-15 can be set or determined to be 8, and the maximum value of K for the base station and UE supporting Rel-16 can also be set to 8. If the maximum value of K for base stations and UEs supporting Rel-15 and the maximum value of K for base stations and UEs supporting Rel-16 are both set to 8, the base station can instruct the UE to select a beam for PDSCH through DCI-based beam selection for one CORESET. The selection of the beam can be determined by identifying the TCI field information 10-41 in the DCI among up to eight beams. Fig. 10BThe TCI field #I indicated in the DCI can be selected as a value from 0 to 7. For example, if the TCI field in the DCI is indicated as 000, it can be determined that among TCI#0', TCI#1', TCI#2', TCI#3', TCI#4', TCI#5', TCI#6' and TCI#7', TCI#0' (TCI#I=TCI#0') is indicated. Although in the above-mentioned embodiments of the present disclosure, the maximum value of K of the base station and UE supporting Rel-15 and the maximum value of K of the base station and UE supporting Rel-16 are respectively set to 8 (K=8), the maximum value of K of the base station and UE supporting Rel-15 and the maximum value of K of the base station and UE supporting Rel-16 can both be set to a value less than 8. Although in the above-mentioned embodiments of the present disclosure, the maximum value K of MAC CE of Rel-15 and the maximum value K of MAC CE of Rel-16 are the same, the maximum value K of MAC CE of Rel-15 and the maximum value K of MAC CE of Rel-16 can be set to different values.

[0307] As another example, if the number of TCI states increases in proportion to the number of base stations / TRPs operating as C-JT / NC-JT, the maximum value of K for base stations and UEs supporting Rel-16 may be set to 16 when two TRPs are operating. When the maximum value of K is set to 16, the base station may instruct the UE to select one or two or more beams for the PDSCH through a DCI-based beam selection of a CORESET. When K is 16, the TCI field #I selected and indicated by the base station may be selected as a value of 0 to 15. Although in the above-mentioned embodiments of the present disclosure, the maximum value of K for the MAC CE of Rel-15 and the maximum value of K for the MAC CE of Rel-16 are set to 16 (K=16), the maximum value of K for the MAC CE of Rel-15 and the maximum value of K for the MAC CE of Rel-16 may be set to a value less than 16.

[0308] Table 15 shows the characteristics of the UE capability reporting parameters "PDSCH beam switching (or timeDurationForQCL, UE capa 2-2)" and "maximum number of downlink RS resources and activated spatial relationship information for QCL type D in activated TCI state (or UE capa 2-62)" for QCL-TypeD.

[0309] Referring to Table 15, the UE can report to the base station through timeDurationForQCL the time interval required to change the receive beam from a minimum of 7 symbols to a maximum of 28 symbols based on a 60kHz subcarrier spacing (SCS), or can report the time interval required to change the receive beam from a minimum of 14 symbols to a maximum of 28 symbols based on a 120kHz subcarrier spacing (SCS). 60kHz and 120kHz SCS are values ​​that can only be set in FR2, and it can be determined from Table 15 that timeDurationForQCL is also available only in FR2.

[0310] In addition, the UE can inform the base station through "UE capa 2-62" how many downlink reference signals can be used as reference RSs of QCL type D in the activated TCI state. For example, if the value of "UE capa 2-62" is 1, it means that there is only one reference RS of QCL type D in the activated TCI state-that is, it can be interpreted as the inability to dynamically change the receiving beam. On the other hand, if the value of "UE capa 2-62" is 2 or more, it means that there are two or more reference RSs of QCL type D in the activated TCI state, and it can be understood as the ability to dynamically change the receiving beam.

[0311] [Table 15]

[0312]

[0313] The base station based on Rel-15 can allocate data considering the scheduling time offset (t_so) from the time when the reception of the PDCCH in the CORESET is completed to the time when the PDSCH scheduled by the PDCCH is transmitted. The scheduling time offset (t_so) is the time (or duration) from the last symbol (or next symbol) of the PDCCH used to allocate the PDSCH to the previous symbol, where the PDSCH used to transmit data is in the combination of the above Figure 8 The starting symbol of the PDSCH may be determined according to the start and length indicator (SLIV) index set in the startSymbolAndLength (0 to 127) of the PDSCH-TimeDomainResourceAllocation set in a higher layer. Depending on the capabilities of the UE, the application of beamforming may be different for each UE, and the capabilities are passed to the base station as a timeDurationForQCL value during the RRC configuration process with the base station. In an embodiment of the present disclosure, timeDurationForQCL may be referred to as a time interval for which the UE applies QCL or a time interval for which QCL is applied.

[0314] Basically, the UE can perform the following operations according to the values ​​of the scheduling time offset (t_so) and timeDurationForQCL based on the capabilities of the UE set in a higher layer.

[0315] When the tci-PresentinDCI field is not set to "enabled" in higher layer configuration, the UE can determine whether the scheduling offset / scheduling timing offset between PDCCH and PDSCH is equal to or greater than the timeDurationForQCL reported through the UE capability report, regardless of the DCI format.

[0316] When the TCI-PresentinDCI field is set to "enabled" in higher layer configuration and the UE receives DCI format 1_1 from the base station, the UE may assume that the TCI field is present in the DCI and determine whether the scheduling time offset between PDCCH and PDSCH is equal to or greater than the timeDurationForQCL reported by the UE capability report.

[0317] When the scheduling offset / scheduling timing offset between PDCCH and PDSCH is less than timeDurationForQCL, the UE may determine the DMRS port of the received PDSCH based on the QCL parameters used in the CORESET with the lowest CORESET ID associated with the monitored search space in the latest time slot.

[0318] Further, as an example, when the scheduling offset / scheduling timing offset between the PDCCH and the PDSCH is greater than or equal to timeDurationForQCL, the UE applies the same QCL assumption as that of the CORESET used to transmit the PDCCH to the corresponding PDSCH DMRS port.

[0319] As another example, when the scheduling offset / scheduling timing offset between PDCCH and PDSCH is greater than or equal to timeDurationForQCL, the UE applies the QCL assumption indicated by the TCI field in the corresponding PDCCH (DCI) to the corresponding PDSCH DMRS port.

[0320] When none of the TCI states "for all BWPs" set in the UE include QCL-TypeD, the UE can derive QCL assumptions based on the TCI state that is always indicated, regardless of the interval between the DCI and the PDSCH to which the DCI is allocated. Fig.11 , 12 , 13 and 14 describe the structure of the PDCCH transmitted by the base station according to at least one CORESET and search space set.

[0321] Fig.11 is a diagram illustrating a method of cooperative communication based on a single PDCCH according to an embodiment of the present disclosure.

[0322] Fig.12 is a diagram illustrating cooperative communication based on multiple PDCCHs according to an embodiment of the present disclosure.

[0323] Fig.13 is a diagram illustrating cooperative communication based on multiple PDCCHs according to an embodiment of the present disclosure.

[0324] Fig.14 is a diagram illustrating cooperative communication based on multiple PDCCHs according to an embodiment of the present disclosure.

[0325] Reference Fig.11 , 12 , 13 and 14, which show the base station in Figure 8 An embodiment of sending the first PDCCH in a CORESET (e.g., the first CORESET or PDCCH#1) is shown in FIG. Specifically, the first PDCCH transmitted in TRP-A can schedule one or more PUCCH resources and at least two or more PDSCHs. DMRS ports in different CDM groups can be respectively applied to multiple PDSCHs sent from the base station, and the DMRS transmission symbol sent with each PDSCH can be located in the same symbol.

[0326] The base station may maintain the PDCCH beam direction (TCI state) in a specific CORESET that the base station transmits in the same beam direction for a specific UE unless updated separately by the MAC CE. Fig.11 , 12 , 13 and 14, the Nth PDCCH (PDCCH#N) 11-15 transmitted from the base station / TRP A indicates the PDCCH in the CORESET with the lowest CORESETID associated with the monitored search space in the latest time slot. That is, if the UE does not receive the PDCCH beam change update message, the UE applies the QCL parameters for receiving the Nth PDCCH in the CORESET with the lowest CORESET ID associated with the monitored search space in the latest time slot, even when the first PDCCH is received in the same manner. Although it has been described above that the Nth PDCCH is transmitted in different search spaces in the same CORESET and is transmitted to the first PDCCH in the previous time slot, it may also be transmitted in different search spaces in the same time slot.

[0327] exist Fig.11 , 12, 13 and 14, the first PDCCH and the second PDCCH may indicate the allocation of the first PDSCH and the second PDSCH for NC-JT transmission, in which case the beamforming direction of the PDSCH may be changed according to the beamforming information configured at a higher layer, the TCI information of the DCI in the first PDCCH or the second PDCCH, the antenna port information or the RNTI information. The UE may identify the beamforming direction changed by the base station based on the received beamforming information and the DCI information.

[0328] Reference Fig.11 , the beamforming direction of the first PDCCH may be different from the beamforming direction of the first PDSCH and the beamforming direction of the second PDSCH for NC-JT transmission. As another example, the beamforming direction of the first PDCCH may be the same as the beamforming direction of the first PDSCH or the beamforming direction of the second PDSCH for NC-JT transmission. As another example, the base station may set the beamforming direction of the first PDSCH and the beamforming direction of the second PDSCH to be different from each other in consideration of the spatial beamforming gain.

[0329] and Fig.11 The related description is the operation of the base station and the UE according to the relationship between timeDurationForQCL and the scheduling timing offset, where the scheduling timing offset includes the number of symbols or the duration between the start symbol of the PDSCH received by the UE and the last symbol of the first PDCCH.

[0330] Although this article defines the scheduling timing offset as the number of symbols between the starting symbol of the PDSCH corresponding to the PDCCH and the last symbol of the PDCCH, the embodiments of the present disclosure are not limited to this and can also be defined in various other ways, such as a predetermined number of symbol units or time slot units.

[0331] Example 1-1

[0332] As an example, for a UE in which the tci-PresentinDCI field is not set to "enabled", the base station does not support NC-JT-based transmissions scheduled using a single PDCCH. That is, the base station may allocate only one PDSCH in one PDCCH for a UE in which the tci-PresentinDCI field is not set to "enabled". After all, when the base station allocates two or more PDSCHs to a specific UE through a single PDCCH scheduling, NC-JT-based transmissions may be performed only on UEs in which the tci-PresentinDCI field is set to "enabled". However, NC-JT-based transmissions may be performed by scheduling using multiple PDCCHs, and instructions related thereto will be described in addition in conjunction with Example 5-1.

[0333] As another example, the base station may indicate to a UE in which the tci-PresentinDCI field is not set to "enabled" a NC-JT-based transmission scheduled using a single PDCCH using antenna port information within a single PDCCH. Specifically, the base station may indicate to the UE in the antenna port information information related to DMRS mapped to different CDM groups, thereby providing information related to multiple PDSCHs to be sent by the base station.

[0334] Example 1-2

[0335] The base station can support NC-JT based transmission by scheduling in a single PDCCH with DCI format 1_1 for UEs in which the tci-PresentinDCI field is set to "enabled". In addition, in NC-JT based transmission, the base station can perform data transmission to the UE considering the scheduling time offset (t_so) between a single PDCCH and multiple PDSCHs.

[0336] Fig.11 11-00 represents an example in which the value of t_so scheduled by the base station is 14 or more. When the calculated value of t_so is 14 or more, the base station may determine and operate using at least one of the methods proposed below.

[0337] As an example, the base station may send the first PDCCH (DCI format 1_1) and the first PDSCH 11-20 and the second PDSCH 11-25 allocated by the first PDCCH 11-10 to a specific UE in which the tci-PresentinDCI field is set to "enabled". In this case, the base station may send both the first PDSCH 11-20 and the second PDSCH 11-25 based on the scheduling algorithm of the base station, without considering the timeDurationForQCL of the UE. For example, the base station may indicate the beamforming direction in which the PDSCH (i.e., the first PDSCH and the second PDSCH) is sent using the antenna port information and TCI information in the DCI of the first PDCCH 11-10. In this case, the capabilities of the UE are not considered when scheduling.

[0338] As another example, if the base station determines that the UE can receive at least one PDSCH based on the indicated timeDurationForQCL information of the UE and the TCI state-related information of the first PDSCH and the second PDSCH, the base station can send the first PDCCH and the first PDSCH and the second PDSCH allocated by the first PDCCH to the UE for NC-JT-based transmission of the UE.

[0339] As another example, if the base station determines that the UE can receive two PDSCHs based on the indicated UE's timeDurationForQCL information and TCI state-related information of the first PDSCH and the second PDSCH, the base station can send the first PDCCH and the first PDSCH and the second PDSCH allocated by the first PDCCH to the UE.

[0340] Example 2-1

[0341] As an example, when the tci-PresentinDCI field is not set to "enabled", the UE does not expect NC-JT based transmission. That is, when the tci-PresentinDCI field is not set to "enabled" or DCI format 1_0 is received, the UE may only regard it as one PDSCH corresponding to one PDCCH being transmitted. For example, the UE may determine that the beamforming direction of the first PDCCH is the same as the beamforming direction of the PDSCH indicated by the first PDCCH.

[0342] As another example, when the TCI-PresentinDCI field is not set to "Enabled", the UE can determine whether to perform NC-JT transmission based on the antenna port information included in the DCI. That is, the antenna port information may include information about whether the base station sends a single PDSCH or multiple PDSCHs. For example, the UE may determine that at least one of the beamforming direction of the first PDCCH, the beamforming direction of the first PDSCH indicated by the first PDCCH, and the beamforming direction of the second PDSCH is the same. Alternatively, the UE may determine that the beamforming direction of the first PDCCH, the beamforming direction of the first PDSCH indicated by the first PDCCH, and the beamforming direction of the second PDSCH is set to the default TCI state.

[0343] Example 2-2

[0344] When the UE receives a message from the base station in which the tci-PresentinDCI field is set to "enabled" and receives DCI format 1_1 of the first PDCCH, the UE can calculate the scheduling time offset (t_so) and compare the calculated time offset (t_so) with the UE capability parameter timeDurationForQCL reported to the base station (e.g., S14).

[0345] Fig.11 11-00 represents an example in which the value of t_so calculated by the UE is 14 or more. When the value of t_so is 14 or more, the UE may operate using at least one of the methods proposed below.

[0346] As an example, the UE may assume that the TCI field is present in the corresponding DCI and apply the QCL parameters (or QCL parameter set) of the TCI state, indicating the beamforming direction for at least one or more PDSCHs indicated by the TCI code point.

[0347] As another example, if the information indicated by the TCI code point includes a TCI state, the UE may assume that the TCI state of one of the two PDSCHs is the same as the TCI of the PDCCH. The UE may receive data by applying the QCL parameters of the first PDSCH and the second PDSCH based on the information of the configured TCI field.

[0348] Fig.11 11-50 shows an example in which the t_so value between the PDCCH and the PDSCH transmitted by the base station is less than 14. When the value of t_so is less than 14, the base station may determine and operate using at least one of the methods proposed below.

[0349] Example 3-1

[0350] In an embodiment of the present disclosure, when the base station does not set the tci-PresentinDCI field to "enabled", the base station may operate in the same manner as in Embodiment 1-1.

[0351] Example 3-2

[0352] In this embodiment of the present disclosure, an operation is described when the base station sets the tci-PresentinDCI field to "enabled" and transmits DCI format 1_1 through the first PDCCH.

[0353] As an example, the base station may send the first PDCCH and all of the first PDSCH and the second PDSCH allocated by the first PDCCH according to the scheduling algorithm of the base station, without considering the timeDurationForQCL of the UE based on NC-JT transmission for a specific UE.

[0354] For example, the base station may use the antenna port information and TCI information in the DCI transmitted through the first PDCCH to indicate the beamforming direction applied to the PDSCH (ie, the first PDSCH and the second PDSCH). In this case, the capability of the UE is not considered in scheduling.

[0355] As another example, when it is determined that the UE cannot receive at least one PDSCH based on the TCI state related information of the first PDSCH and the second PDSCH as indicated and the timeDurationForQCL information of the UE for transmitting the first PDCCH and the first PDSCH and the second PDSCH allocated by the first PDCCH for NC-JT-based transmission for a specific UE, the base station can transmit only the receivable PDSCH (e.g., the first PDSCH ( Fig.11 PDSCH#1)).

[0356] As another example, when it is determined that the UE cannot receive at least one PDSCH based on the TCI state related information of the first PDSCH and the second PDSCH as indicated and the timeDurationForQCL information of the UE for transmitting the first PDCCH and the first PDSCH and the second PDSCH allocated by the first PDCCH for NC-JT-based transmission for a specific UE, the base station may determine based on the TCI state that can be received by the UE (e.g., for receiving the first PDCCH (e.g., Fig.11 1) or the Nth PDCCH (e.g., Fig.11The TCI state of PDCCH#N) is used to transmit at least one of the first PDSCH and the second PDSCH.

[0357] As another example, when it is determined that the UE cannot receive at least one PDSCH when only the timeDurationForQCL information of the UE is considered, in order to transmit the first PDCCH and the first PDSCH and the second PDSCH of the NC-JT-based transmission for the specific UE, the base station can avoid performing all PDSCHs (e.g., the first PDSCH and the second PDSCH ( Fig.11 Transmission of PDSCH#1 and PDSCH#2)).

[0358] When the UE receives a message from the base station in which the tci-PresentinDCI field is set to "enabled" and receives DCI format 1_1 through the first PDCCH, the UE can calculate the scheduling time offset (t_so) and compare the calculated scheduling time offset (t_so) with the UE capability parameter timeDurationForQCL reported by the UE to the base station (e.g., S14).

[0359] Fig.11 11-50 indicate an example in which the value of t_so calculated by the UE is less than 14. When the value of t_so is less than 14, the UE may operate using at least one of the methods proposed below.

[0360] Example 4-1

[0361] If the scheduling time offset (t_so) value calculated by the UE is less than the UE capability parameter timeDurationForQCL reported to the base station (eg, S14), the UE does not expect the NC-JT based transmission of the base station.

[0362] For example, if the timeDurationForQCL required to apply the TCI state-related QCL parameter indicating the beamforming direction for the PDSCH is not satisfied, the UE may skip all PDSCH reception operations indicated in the PDCCH.

[0363] As another example, if the timeDurationForQCL required for the UE to apply the TCI state-related QCL parameter indicating the beamforming direction for the PDSCH is not satisfied, the UE, when receiving the first PDSCH or the second PDSCH, may apply the QCL parameter for receiving the Nth PDCCH in the CORESET with the lowest CORESET ID associated with the monitored search space in the latest time slot. Specifically, the UE may decode and the QCL parameter is applied to both the first PDSCH and the second PDSCH. Therefore, if the base station performs NC-JT transmission with different beamforming directions applied, the UE expects to selectively successfully receive only one of the two PDSCHs (i.e., the first PDSCH and the second PDSCH).

[0364] Example 4-2

[0365] If the scheduling time offset (t_so) value calculated by the UE is less than the UE capability parameter timeDurationForQCL reported to the base station (eg, S14), the UE desires to perform transmission based on a single transmission in the base station.

[0366] For example, if the timeDurationForQCL required for the UE to apply the TCI state-related QCL parameter indicating the beamforming direction for the PDSCH is not met, the UE may use the QCL parameter for receiving the Nth PDCCH in the CORESET with the lowest CORESET ID associated with the monitored search space in the latest time slot. Therefore, the UE can receive data in the PDSCH (e.g., the first PDSCH / second PDSCH) of the lowest / highest resource RB allocated to the first PDSCH and the second PDSCH, and the QCL parameter can be used at this time. As another example, if the timeDurationForQCL required for the UE to apply the TCI state-related QCL parameter indicating the beamforming direction for the PDSCH is not met, the UE may apply the QCL parameter for receiving the Nth PDCCH in the CORESET with the lowest CORESET ID associated with the monitored search space in the latest time slot to the first PDSCH or the second PDSCH. The DMRS port configuration for receiving the first PDSCH and the second PDSCH may be received based on the antenna port information in the DCI.

[0367] In the above embodiments of the present disclosure, the UE desires to set a default QCL in a single PDCCH-based NC-JT transmission in a CORESET.

[0368] In addition, in NC-JT based on a single PDCCH within a CORESET, the UE is expected to configure two or more default QCLs. When two or more default QCLs are configured, it means that the UE can apply QCL parameters to two PDSCHs (e.g., the first PDSCH and the second PDSCH) according to the information previously configured by the base station. The QCL parameters to be applied can be set implicitly or externally through DCI information (e.g., antenna port information and TCI information), MAC CE, or RRC information indicated to the UE.

[0369] For example, when the base station configures at least two or more default QCLs for each CORESET or each PDCCH-config, the base station can set the respective beamforming directions of the TRPs to the same beamforming directions as the UE side performing the receiving operation based on at least two or more default QCLs. Alternatively, each of the multiple TRPs can be set to a TCI state assuming that the UE performs the same beamforming. In this case, the UE can determine that the TCI state is the same based on the MAC CE or RRC information set internally or externally to the base station, and can perform the receiving operation based on the same TCI state. Considering the location and channel of the TRP, the TCI states may be the same or different from each other. That is, the UE can perform receive beamforming in the same direction by applying QCL parameters to two PDSCHs (e.g., the first PDSCH and the second PDSCH).

[0370] As another example, when the base station sets at least two or more default QCLs for each CORESET or each PDCCH-config, the base station may set the two or more default QCLs to be the same as each other. That is, although two default QCLs are explicitly set, the two default QCLs may be set to indicate the same beamforming direction. In this case, the UE may recognize the same TCI state set by the base station and perform the same beamforming. Alternatively, the UE may perform a receiving operation based on one TCI state assuming that multiple TCI states for the default QCL set by the base station are the same. That is, the UE may perform receive beamforming in the same direction by applying the QCL parameters set to be the same to two PDSCHs (e.g., the first PDSCH and the second PDSCH).

[0371] Meanwhile, the base station may sequentially set at least two or more default QCLs per CORESET or per PDCCH-config. Alternatively, in some cases, there may be a state where two or more default QCLs are not fully set but only one default QCL is set.

[0372] As an example, the base station may set the default QCL of the first PDSCH at a first time, and may set the default QCL of the second PDSCH at a second time, the second time being later than the first time, or may not set the default QCL of the second PDSCH. In the case where the default QCL of the second PDSCH is not set, if only one ServingCell, PDCCH-config or the default QCL of the first PDSCH set in the CORESET (group) of each TRP is configured, the UE may determine that the default QCL of the second PDSCH is the same as the default QCL of the first PDSCH. Alternatively, the UE may determine that the default QCL of the second PDSCH is unnecessary, thereby determining that it is not scheduled within the scheduling time offset. Alternatively, the UE may determine that the transmission of the second PDSCH is not performed. That is, unless the base station configures at least two default QCLs, the UE may assume that at least two or more PDSCHs are not transmitted in a time slot in multiple TRPs based on a single DCI after configuring at least two default QCLs. And determine that at least two or more PDSCHs will be transmitted in a time slot in multiple TRPs. Fig.12 An embodiment is shown in which a base station transmits a first PDCCH in one CORESET (eg, CORESET#0 or PDCCH#1) and additionally transmits a second PDCCH in another CORESET (eg, CORESET#1 or PDCCH#2).

[0373] Specifically, the first PDCCH transmitted in TRP-A can schedule one or more PUCCH resources (first PUCCH) and one or more PDSCHs (first PDSCH), and the second PDCCH transmitted in TRP-B can schedule one or more PUCCH resources (second PUCCH) and one or more PDSCHs (second PDSCH). DMRS ports of different CDM groups can be applied to PDSCHs sent from the base station, and the DMRS transmission symbol transmitted with each PDSCH can be located in the same symbol as the symbol transmitting each PDSCH. Although it is assumed that each PDSCH is transmitted in the same symbol as the DMRS transmission symbol, the present disclosure is not limited to that each PDSCH must be transmitted in the same symbol as the DMRS transmission symbol.

[0374] Multiple CORESETs may be individually configured for a base station for multi-DCI based NC-JT transmission. Alternatively, multiple CORESETs may be configured in a set, such as a CORESET group, and may be indicated by L1 / L2 signaling or higher layers of a UE supporting NC-JT.

[0375] For example, for multi-DCI based NC-JT based transmission, the base station may configure a CORESET group including at least one or more CORESETs in a specific UE. Specifically, the base station may configure four CORESETs in a CORESET group in a specific UE, so that the UE can receive two PDCCHs by monitoring the four CORESETs, and receive the PDSCH allocated by the received PDCCH.

[0376] Reference Fig.12 , the base station may configure a CORESET group (e.g., CORESET group #0) in a specific UE, and among a maximum of five CORESETs (e.g., CORESET #0 to CORESET #4) included in the CORESET group, the UE may monitor CORESET #0 and CORESET #1 for NC-JT purposes. In this case, the CORESET monitored by the UE in the CORESET group may be determined according to the configuration of the base station or the configuration of the UE, or may be performed arbitrarily. This method for determining the CORESET monitored by the UE within a specific CORESET group may be applied to other embodiments of the present disclosure.

[0377] As another example, for multi-DCI based NC-JT based transmission, the base station may configure at least two or more CORESET groups including at least one or more CORESETs in a specific UE. For example, the base station may configure two CORESET groups in a specific UE, and configure or indicate a CORESET in one or both of the configured CORESET groups. Therefore, the UE may receive two PDCCHs by monitoring the configured CORESETs, and receive the PDSCH allocated by the received PDCCHs. Fig.12 As shown, the base station may configure two CORESET groups (e.g., CORESET group #0 and CORESET group #1) in a specific UE, and among the CORESETs in the two CORESET groups, CORESET #0 in CORESET group #0 and CORESET #1 in CORESET group #1 may be monitored by the UE for the purpose of NC-JT. In this case, the CORESET monitored by the UE in the CORESET group may be determined according to the configuration of the base station or the configuration of the UE, or may be performed arbitrarily.

[0378] CORESET#0 may include a first PDCCH and an Nth PDCCH, and CORESET#1 may include a second PDCCH and an N+1th PDCCH. The CORESETs configured for each CORESET group may be different (for example, CORESET group #0 may include CORESET#0 and #2, while CORESET group #1 may include CORESET#1, #3, and #5), and the number of CORESETs configured in all CORESET groups is not greater than the maximum number of CORESETs that can be configured in the UE, that is, the number of CORESETs reported in the UE capabilities. In the above-mentioned embodiments of the present disclosure, the maximum number of CORESETs may be 5 or less.

[0379] Unless updated by a MAC CE, the base station may keep the PDCCH beam direction (TCI-STATE) in a specific CORESET sent by the base station the same for a specific UE.

[0380] Fig.12 The Nth PDCCH (PDCCH#N) / N1th PDCCH (PDCCH#N1) transmitted by TRP-A / TRP-B is shown, which are PDCCHs in the CORESET with the lowest CORESET ID associated with the monitored search space in the latest time slot of the respective CORESETs of TRP-A / TRP-B. That is, if the UE does not receive the PDCCH beam change update message, the UE applies the QCL parameters for receiving the Nth PDCCH / N+1th PDCCH in the CORESET with the lowest CORESET ID associated with the monitored search space in the latest time slot, even when the first PDCCH / second PDCCH is received in the same manner.

[0381] Although the above combination Fig.12 An example is described in which the Nth PDCCH (PDCCH#N) / N1th PDCCH (PDCCH#N 1) is transmitted in the same time slot of the first PDCCH / second PDCCH as an embodiment in which they are transmitted in different search spaces in the same CORESET, and the embodiments of the present disclosure do not exclude the situation in which they are transmitted in different search spaces in the previous time slot.

[0382] The first PDCCH and the second PDCCH respectively indicate the allocation of the first PDSCH and the second PDSCH for NC-JT transmission, in which case the beamforming directions of the first PDSCH and the second PDSCH may be changed according to the beamforming information set in the higher layer, the TCI information of the DCI in the first PDCCH and the second PDCCH, the antenna port information or the RNTI information. The UE may identify the beamforming direction changed by the base station based on the received beamforming information and the DCI information.

[0383] As an example, the beamforming direction of the first PDCCH may be different from the beamforming direction of the first PDSCH used for NC-JT transmission, and the beamforming direction of the second PDCCH may be different from the beamforming direction of the second PDSCH used for NC-JT transmission.

[0384] As another example, the beamforming direction of the first PDCCH may be the same as the beamforming direction of the first PDSCH used for NC-JT transmission, or the beamforming direction of the second PDCCH may be the same as the beamforming direction of the second PDSCH used for NC-JT transmission.

[0385] As another example, given the spatial beamforming gain, the base station may set the beamforming direction of the first PDSCH to be different from the beamforming direction of the second PDSCH. Fig.12 , 13 and 14 show the operation of a base station and a UE depending on the relationship between timeDurationForQCL and a scheduling timing offset which is the duration between the last symbol of a first PDCCH received by the UE and the start symbol of a first PDSCH, and depending on the relationship between timeDurationForQCL and a scheduling timing offset which is the duration between the last symbol of a second PDCCH and the start symbol of a second PDSCH.

[0386] Example 5-1

[0387] When the tci-PresentinDCI field for a specific UE is not set to "enabled", the base station can perform scheduling operations for the specific UE without considering the scheduling time offset (t_so) for NC-JT based transmission and timeDurationForQCL reported in the UE capability report.

[0388] Example 5-2

[0389] As an example, when the tci-PresentinDCI field is set to "enabled" for a specific UE, the base station can perform scheduling operations for the specific UE without considering the scheduling time offset (t_so) for NC-JT-based transmission and the timeDurationForQCL reported in the UE capability report. The base station can determine whether to change the transmission beams for the first PDSCH and the second PDSCH based on NC-JT without considering the capabilities of the UE. Therefore, the base station can send the first PDSCH and the second PDSCH based on the TCI field information of the PDCCH used to allocate the first PDSCH and the second PDSCH.

[0390] As another example, when the tci-PresentinDCI field is set to "enabled" for a specific UE, the base station may consider the scheduling time offset (t_so) for NC-JT-based transmission and the timeDurationForQCL reported in the UE capability report to perform scheduling operations for the specific UE. The base station may determine the beamforming direction of the first PDSCH and the second PDSCH based on whether the transmission beams of the first PDSCH and the second PDSCH based on NC-JT are changed.

[0391] For example, Fig.12As shown, the base station may configure CORESET#0 in CORESET group #0 and CORESET#1 in CORESET group #1 in the UE, for NC-JT purposes, CORESET group #0 and CORESET group #1 (for example, CORESET group #0 includes CORESET#0 and #2, and CORESET group #1 includes CORESET#1, #3, and #5), for beam change to occur for the first PDSCH and the second PDSCH in the PDSCH to be jointly transmitted with the PDCCH in CORESET#0 and CORESET#1. Here, the base station may perform at least one of the following comparisons, i.e., a comparison between timeDurationForQCL and a first scheduled time offset which is a duration between the first PDSCH and the first PDCCH for which the PDSCH beam change occurs in a specific UE, or a comparison between timeDurationForQCL and a second scheduled time offset which is a duration between the second PDCCH and the second PDSCH. Therefore, if the first scheduled time offset and the second scheduled time offset according to the beam change are less than timeDurationForQCL, the base station may operate as follows. According to an embodiment of the present disclosure, the base station may apply QCL parameters for transmitting the Nth PDCCH in the CORESET with the lowest CORESET ID (e.g., CORESET #0 and CORESET #1) associated with the monitored search space in the latest time slot in each CORESET group (e.g., CORESET group #0 and CORESET group #1) when transmitting the first PDSCH, and may apply QCL parameters for transmitting the N+1th PDCCH in transmitting the second PDSCH.

[0392] Specifically, if Fig.12 As shown, if PDSCH#1 is scheduled from CORESET group #0, the QCL parameters for PDCCH#N corresponding to the monitored search space of the lowest CORESET ID in the latest slot in CORESET group #0 are used to transmit PDSCH#1.

[0393] If PDSCH#2 is scheduled from CORESET group #1, the QCL parameters used for PDCCH#N+1 are used to send PDSCH#2, similar to the case where PDSCH#1 is scheduled from CORESET group #0. That is, the base station can set up two CORESET groups for NC-JT and match each CORESET group with the corresponding TRP. The QCL assumption for each PDSCH can be referenced from the corresponding lowest CORESET ID in the CORESET group.

[0394] In an embodiment of the present disclosure, QCL parameters for transmitting the Nth PDCCH in a CORESET with a lowest CORESET ID (e.g., CORESET #0) associated with a monitored search space in a latest time slot in a lowest CORESET group (e.g., CORESET group #0) may be applied to each of a first PDSCH transmission and a second PDSCH transmission.

[0395] In an embodiment of the present disclosure, the QCL parameters for transmitting the Nth PDCCH in the CORESET with the lowest CORESET ID (CORESET#0) associated with the monitored search space in the latest time slot in the lowest CORESET group (CORESET group #0) may be applied to transmit the first PDSCH, and the transmission of the second PDSCH may be abandoned or may not be performed. That is, the transmission of the PDSCH may be prioritized according to the lowest CORESET ID.

[0396] As another example, the base station may set CORESETs for NC-JT purposes in one CORESET group #0 (eg, CORESET group #0 includes CORESET #0 and CORESET #1). Fig.12 , it is assumed that CORESET#0 and CORESET#1 are set. The following describes an example in which a beam change for a first PDSCH and a second PDSCH occurs in a PDSCH transmitted jointly with a PDCCH in CORESET#0 and CORESET#1. When a beam change for a PDSCH occurs in a specific UE, the base station may compare timeDurationForQCL with a first scheduled time offset which is a duration between a first PDCCH and the first PDSCH, and compare timeDurationForQCL with a second scheduled time offset which is a duration between a second PDCCH and the second PDSCH. Therefore, in the event that a beam change for a PDSCH occurs, if the first scheduled time offset or the second scheduled time offset is less than timeDurationForQCL, the base station may operate in each of the following embodiments.

[0397] According to an embodiment of the present disclosure, the base station may apply QCL parameters for transmitting the Nth PDCCH in the CORESET associated with the monitored search space based on information for the lowest ID (e.g., CORESET #0) or the second lowest ID (e.g., CORESET #1) in the latest time slot in the CORESET group (e.g., CORESET group #0) in which a beam change occurs when transmitting the first PDSCH, and apply QCL parameters for transmitting the N+1th PDCCH 12-90 when transmitting the second PDSCH.

[0398] According to an embodiment of the present disclosure, when transmitting the first PDSCH or the second PDSCH where a beam change occurs, the base station can apply the QCL parameters for transmitting the Nth PDCCH in the CORESET associated with the monitored search space based on the lowest ID (e.g., CORESET #0) in the latest time slot (e.g., CORESET group #0) in the CORESET group where the beam change occurs.

[0399] According to an embodiment of the present disclosure, when transmitting the first PDSCH, the base station may apply the QCL parameters for transmitting the Nth PDCCH in the CORESET associated with the monitored search space based on the information for the lowest ID (e.g., CORESET #0) in the latest time slot in the CORESET group (e.g., CORESET group #0) where the beam change occurs, and abandon or avoid transmitting the second PDSCH. That is, the transmission of the PDSCH may be prioritized according to the lowest CORESET ID.

[0400] In the above-described embodiments of the present disclosure, there is a CORESET group (for example, CORESET group #0 includes CORESET #0 and CORESET #2). However, in some cases, there may be no CORESET group, or no CORESET group is set and only CORESET exists. Therefore, it is obvious that the scheme in the above-described embodiments is performed based on the CORESET ID, except that there is no CORESET group or no CORESET group is set in the operation according to the above-described embodiments.

[0401] Although in the above-described embodiments of the present disclosure, the lowest CORESET / CORESET group ID is provided, the present disclosure may cover other various embodiments in which the highest CORESET / CORESET group ID as well as the lowest CORESET / CORESET group ID are used or provided.

[0402] As another example, when a beam change occurs for at least one of the PDSCHs to be transmitted, such as the first PDSCH and the second PDSCH, the base station may perform at least one of the following comparisons for a specific UE: a comparison between a first scheduling time offset which is the duration between the first PDCCH and the first PDSCH and timeDurationForQCL or a comparison between a second scheduling time offset which is the duration between the second PDCCH and the second PDSCH and timeDurationForQCL, and, if both the first scheduling time offset and the second scheduling time offset are less than timeDurationForQCL and timeDurationForQCL is a specific value (e.g., s7), the base station may select one of the QCL parameters for transmitting the Nth PDCCH and the QCL parameters for transmitting the N+1th PDCCH, and typically apply the selected one to the beam direction of the first PDSCH and the second PDSCH. The method of selecting one of the QCL parameters for transmitting the Nth PDCCH and the QCL parameters for transmitting the N+1th PDCCH may specifically include selecting the lowest / highest CORESET ID, selecting the PDCCH index allocated in the latest search space, or selecting the longest one considering the time difference between the PUCCH for transmitting the ACK / NACK of the PDSCH and the PDSCH. According to one embodiment, multiple PDSCHs can be transmitted from TRP-A or TRP-B.

[0403] When the UE receives a message from the base station in which the tci-PresentinDCI field is set to "enabled" and receives DCI format 1_1 through the first PDCCH, the UE can calculate the scheduling time offset (t_so) and compare the calculated time offset (t_so) with the UE capability parameter timeDurationForQCL reported to the base station (e.g., S14). Fig.12 An example is shown in which the value of t_so1 and the value of t_so2 calculated by the UE are both less than 14. When the value of t_so is less than 14, the UE may operate according to the method proposed below.

[0404] Example 6-1

[0405] For example, in the case where the UE receives a message in which the tci-PresentinDCI field is set to "enabled" from the base station and receives DCI format 1_1 through the first PDCCH or the second PDCCH, if the calculated scheduling time offset (t_so) value is less than the UE capability parameter timeDurationForQCL reported to the base station (e.g., S14), the UE does not expect to perform NC-JT based transmission. For example, if the timeDurationForQCL required for applying the TCI state-related QCL parameter indicating the beamforming direction of the PDSCH is not satisfied, the UE can skip all PDSCH reception operations indicated in the PDCCH (e.g., the first PDCCH or the second PDCCH).

[0406] As another example, if the timeDurationForQCL required for applying the TCI state-related parameters for the beamforming directions of the first PDSCH and the second PDSCH indicating that a beam change has occurred is not met, the UE may operate as follows, corresponding to Example 5-2.

[0407] The UE may be configured with multiple CORESET groups. In the embodiments of the present disclosure, it is assumed that the first PDSCH is jointly allocated with the PDCCH in the CORESE in CORESET group #0, and the second PDSCH is jointly allocated with the PDCCH in the CORESE in CORESET group #1.

[0408] According to an embodiment of the present disclosure, the UE may apply the first QCL parameter-related information for receiving the Nth PDCCH in the CORESET with the lowest CORESET ID (e.g., CORESET#0 or CORESET#1) associated with the monitored search space in the latest time slot in the CORESET group (e.g., CORESET group #0 or CORESET group #1) where the beam change occurs when receiving the first PDSCH, and apply the second QCL parameter-related information for receiving the N+1th PDCCH when receiving the second PDSCH. Specifically, the UE may perform decoding by applying the first QCL parameter-related information and the second QCL parameter-related information to the first PDSCH and the second PDSCH, respectively.

[0409] As an embodiment of the present disclosure, the UE may apply the first QCL parameter-related information for receiving the Nth PDCCH in the CORESET with the lowest CORESET ID (e.g., CORESET #0) associated with the monitored search space in the latest time slot of the lowest CORESET group in the CORESET group (e.g., CORESET group #0 and CORESET group #1) where beam change occurs when receiving the first PDSCH and receiving the second PDSCH.

[0410] According to an embodiment of the present disclosure, the UE may apply the first QCL parameter related information for receiving the Nth PDCCH in the CORESET with the lowest CORESET ID (e.g., CORESET #0) associated with the monitored search space in the latest time slot of the lowest CORESET group in the CORESET group (e.g., CORESET group #0 and CORESET group #1) where beam change occurs when receiving the first PDSCH, and abandon or avoid receiving the second PDSCH. That is, the PDSCH may be preferentially received according to the lowest CORESET ID.

[0411] As another example, if the timeDurationForQCL required for applying the TCI state-related parameters for the beamforming directions of the first PDSCH and the second PDSCH indicating that a beam change has occurred is not met, the UE may operate as follows, corresponding to Example 5-2.

[0412] The UE may be configured with multiple CORESET groups. In the embodiments of the present disclosure, it is assumed that the first PDSCH and the second PDSCH are jointly allocated with the PDCCH in CORESET group #0 (eg, CORESET group #0 includes CORESET #0 to CORESET #4).

[0413] According to an embodiment of the present disclosure, the UE may, when receiving the first PDSCH, apply QCL parameters for receiving the Nth PDCCH in the CORESET associated with the monitored search space or / and QCL parameters for receiving the N+1th PDCCH when receiving the second PDSCH based on information of the lowest CORESET ID (e.g., CORESET#0) or / and the second lowest ID (e.g., CORESET#1) in the latest time slot in the CORESET group (e.g., CORESET group #0) where the beam change occurs.

[0414] Specifically, in Fig.12In the description of receiving PDSCH #1, if PDSCH #1 is scheduled from CORESET group #0, the UE uses the QCL parameters for PDCCH #N corresponding to the monitored search space of the lowest CORESET ID in the latest slot in CORESET group #0 when receiving PDSCH #1. If PDSCH #2 is scheduled from CORESET group #1, the UE uses the QCL parameters for PDCCH #N+1 when receiving PDSCH #2, just as in the description of receiving PDSCH #1.

[0415] According to an embodiment of the present disclosure, the UE can apply QCL parameters for receiving the Nth PDCCH in the CORESET associated with the monitored search space based on information of the lowest ID (e.g., CORESET#0) in the latest time slot in the CORESET group (e.g., CORESET group #0) where the beam change occurs when receiving the first PDSCH or / and the second PDSCH where the beam change occurs.

[0416] According to an embodiment of the present disclosure, the UE may apply the QCL parameter for receiving the Nth PDCCH in the CORESET associated with the monitored search space based on the information of the lowest ID (e.g., CORESET #0) in the latest time slot in the CORESET group (e.g., CORESET group #0) in which the beam change occurs in receiving the first PDSCH, and abandon or avoid receiving the second PDSCH. That is, the PDSCH may be preferentially received according to the lowest CORESET ID.

[0417] Although the above-described embodiments consider the lowest CORESET ID, the present disclosure may also encompass embodiments that consider the highest CORESET ID as well as the lowest CORESET ID.

[0418] In the above-described embodiments of the present disclosure, there is a CORESET group (for example, CORESET group #0 includes CORESET #0 to CORESET #4). However, in some cases, there may be no CORESET group, or no CORESET group is set and only CORESET exists. Therefore, it is obvious that the scheme in the above-described embodiments is performed based on the CORESET ID, except that there is no CORESET group or no CORESET group is set in the operation according to the above-described embodiments.

[0419] As another example, if no UE applies the timeDurationForQCL required by the TCI state-related QCL parameter indicating the beamforming direction of the first PDSCH and the second PDSCH, the UE may select at least one of the first QCL parameter-related information and the second QCL parameter-related information for receiving the Nth PDCCH in the CORESET with the lowest CORESET ID associated with the monitored search space in the latest time slot in each CORESET, and apply the selected QCL parameter-related information to both the first PDSCH and the second PDSCH for decoding. The method for selecting at least one of the first QCL parameter-related information and the second QCL parameter-related information may specifically include: selecting the lowest / highest CORESET ID among multiple CORESETs, selecting a PDCCH index allocated in the latest search space, or selecting the longest one taking into account the transmission time difference between the PUCCH for sending the ACK / NACK of the PDSCH and the PDSCH. According to one embodiment, multiple PDSCHs may be sent from TRP-A or TRP-B.

[0420] Example 6-2

[0421] For example, when the tci-PresentinDCI field is not set to "enabled" or the UE receives DCI format 1_0 from the base station, the UE can receive multiple PDSCHs based on NC-JT transmission without considering the timeDurationForQCL reported by the UE capability report. That is, when the tci-PresentinDCI field is not set to "enabled" or the UE receives DCI format 1_0 from the base station, the UE can regard it as allocating and transmitting only one PDSCH in one PDCCH. For example, the UE can determine that the beamforming direction of the first PDCCH and the beamforming direction of the first PDSCH indicated by the first PDCCH are the same as each other, and can determine that the beamforming direction of the second PDCCH and the beamforming direction of the second PDSCH indicated by the second PDCCH are the same as each other.

[0422] As another example, if the tci-PresentinDCI field is not set to "enabled", the UE may determine that PDSCH transmission based on NC-JT transmission is not supported.

[0423] Fig.13 13-00 shows an example in which one of the values ​​of t_so1 and t_so2 calculated by the UE is less than 14. According to an embodiment of the present disclosure, when the value of t_so2 among the multiple t_so values ​​(ie, the value of t_so1 and the value of t_so2) is less than 14, the base station and the UE may operate based on the method proposed below.

[0424] Example 7-1

[0425] As described above in conjunction with Example 5-1, if the tci-PresentinDCI field is not set to "enabled" for a specific UE, the base station can perform scheduling for NC-JT-based transmissions without the timeDurationForQCL and scheduling time offset (t_so) reported in the UE capability report.

[0426] Example 7-2

[0427] As an example, as described above in combination with Example 5-2, when the tci-PresentinDCI field is set to "enabled" for a specific UE, the base station can perform scheduling operations for NC-JT based transmissions without considering the scheduling time offset (t_so) and timeDurationForQCL reported in the UE capability report.

[0428] As another example, when the tci-PresentinDCI field is set to "enabled" for a specific UE, the base station may perform scheduling operations for NC-JT-based transmissions taking into account the timeDurationForQCL reported in the UE capability report and the scheduling time offset (t_so). The base station may determine the beamforming directions of the first PDSCH and the second PDSCH based on NC-JT based on whether the transmit beams of the first PDSCH and the second PDSCH are changed.

[0429] Reference Fig.13, the base station may configure CORESET#0 included in CORESET group #0 and CORESET#1 included in CORESET group #1 as CORESETs of UEs of CORESET group #0 and CORESET group #1 for NC-JT purposes (e.g., CORESET group #0 includes CORESET#0 and #2, and CORESET group #1 includes CORESET#1, #3, and #5), beam changing occurs in a first PDSCH and a second PDSCH in a PDSCH jointly transmitted with a PDCCH in a CORESET (i.e., CORESET#0 included in CORESET group #0 and CORESET#1 included in CORESET group #1). Here, the base station may perform at least one of a comparison between a first scheduling time offset (t_so1) which is a duration between a first PDCCH and a first PDSCH and timeDurationForQCL, or a comparison between a second scheduling time offset (t_so2) which is a duration between a second PDCCH and a second PDSCH and timeDurationForQCL. When one of the first scheduling time offset and the second scheduling time offset is less than timeDurationForQCL, the following operations may be performed: In the embodiment of the present disclosure, it is assumed that t_so2 is less than timeDurationForQCL.

[0430] According to an embodiment of the present disclosure, the base station may apply, when transmitting the second PDSCH, the QCL parameters for sending the N+1th PDCCH in the CORESET with the lowest CORESET ID (e.g., CORESET #1) associated with the monitored search space in the latest time slot based on the CORESET group (e.g., CORESET group #0 and CORESET group #1) in which the scheduling time offset value is less than timeDurationForQCL and the CORESET ID in the group.

[0431] Specifically, in Fig.13 In the embodiment, when PDSCH#2 is scheduled from CORESET group#1, the QCL parameters of PDCCH#N+1 corresponding to the monitored search space of the lowest CORESET ID of the latest slot in the CORESET group are used to transmit PDSCH#2.

[0432] According to an embodiment of the present disclosure, the base station may apply, when transmitting the second PDSCH, QCL parameters for transmitting the Nth PDCCH in the CORESET with the lowest CORESET ID (e.g., CORESET #0) associated with the monitored search space in the latest time slot in the lowest CORESET group (CORESET group #0) in the CORESET groups (e.g., CORESET group #0 and CORESET group #1).

[0433] According to an embodiment of the present disclosure, the base station may apply QCL parameters according to the beamforming direction indicated in the CORESET (e.g., CORESET#0) in the CORESET group (e.g., CORESET group #0) in which the scheduling time offset value is equal to or greater than timeDurationForQCL (i.e., for information via the TCI field of the second PDCCH), and the beamforming direction of the PDSCH (second PDSCH) scheduled in the CORESET (e.g., CORESET#1) in the CORESET group (e.g., CORESET group #1) in which the scheduling time offset value is less than timeDurationForQCL. In this case, if the change in the beamforming direction is not indicated by the first PDCCH, the base station may apply the QCL parameters of the first PDCCH (or the first PDSCH) to the second PDSCH.

[0434] According to an embodiment of the present disclosure, the base station may compare t_so1 with timeDurationForQCL or compare t_so2 with timeDurationForQCL regardless of each CORESET group, and if t_so1 or t_so2 is less than timeDurationForQCL, the base station may avoid (stop or skip) transmitting to a specific UE the PDSCH (e.g., the second PDSCH) scheduled in the CORESET (e.g., CORESET#1) corresponding to the scheduling time offset less than timeDurationForQCL.

[0435] As another example, a case is described in which the base station may configure CORESETs (CORESET#0 and CORESET#1) for NC-JT purposes for a specific UE in one CORESET group #0 (e.g., CORESET group #0 includes CORESET#0 and CORESET#1), and a beam change occurs for at least one of the PDSCHs to be transmitted jointly with the PDCCHs in the CORESETs (i.e., CORESET#0 and CORESET#1). Here, the base station may perform one of the following comparisons: a comparison between timeDurationForQCL and a first scheduling time offset (the first scheduling time offset is a duration between a first PDSCH and a first PDCCH for which a beam change occurs for the PDSCH), or a comparison between timeDurationForQCL and a second scheduling time offset (the second scheduling time offset is a duration between a second PDCCH and a second PDSCH). If the first scheduling time offset or the second scheduling time offset is less than timeDurationForQCL when a beam change occurs for the PDSCH, the base station may operate in various embodiments.

[0436] According to an embodiment of the present disclosure, the base station can apply the QCL parameters for transmitting the Nth PDCCH in the CORESET with the lowest CORESET ID (e.g., CORESET#0) associated with the monitored search space in the latest time slot based on the CORESET ID corresponding to the scheduling time offset less than timeDurationForQCL in the CORESET group (e.g., CORESET group #0) when transmitting the second PDSCH.

[0437] According to an embodiment of the present disclosure, the base station may apply, in transmitting the second PDSCH, the QCL parameters for transmitting the Nth PDCCH in the CORESET with the lowest CORESET ID (e.g., CORESET #0) associated with the monitored search space in the latest time slot in the lowest CORESET group (CORESET group #0) in the CORESET group (e.g., CORESET group #0).

[0438] According to an embodiment of the present disclosure, the base station may apply QCL parameters for NC-JT transmission according to the beamforming direction indicated in the CORESET (e.g., CORESET#0) corresponding to the scheduling time offset equal to or greater than timeDurationForQCL (i.e., for the information of the TCI field indicated via the second PDCCH), and the beamforming direction of the PDSCH (second PDSCH) scheduled in the CORESET (e.g., CORESET#1) corresponding to the scheduling time offset less than timeDurationForQCL. In this case, if the base station does not indicate a change in the beam direction through the first PDCCH, the second PDSCH may apply the QCL parameters of the first PDCCH (or the first PDSCH).

[0439] According to an embodiment of the present disclosure, the base station may compare t_so1 with timeDurationForQCL or t_so2 with timeDurationForQCL for a specific UE regardless of each CORESET group used for NC-JT transmission, and if t_so1 or t_so2 is less than timeDurationForQCL, the base station may not transmit the PDSCH (e.g., the second PDSCH) scheduled in the CORESET (e.g., CORESET#1) corresponding to the scheduling time offset less than timeDurationForQCL.

[0440] In the above-described embodiments of the present disclosure, there is a CORESET group (for example, CORESET group #0 includes CORESET #0 and CORESET #2). However, in some cases, there may be no CORESET group, or no CORESET group is set and only CORESET exists. Therefore, it is obvious that the scheme in the above-described embodiments is performed based on the CORESET ID, except that there is no CORESET group or no CORESET group is set in the operation according to the above-described embodiments.

[0441] Although the above-described embodiments consider the lowest CORESET / CORESET group ID, the present disclosure may also encompass embodiments that consider the highest CORESET / CORESET group ID as well as the lowest CORESET / CORESET group ID.

[0442] Example 8-1

[0443] In the case where the UE receives a message from the base station in which the tci-PresentinDCI field is set to "enabled" and receives DCI format 1_1 through the first PDCCH or the second PDCCH, if the calculated scheduling time offset (t_so) value in one CORESET is less than the UE capability parameter timeDurationForQCL reported to the base station (e.g., S14), the UE does not expect to perform NC-JT-based transmission. For example, when the value of t_so1 is 14 or greater and the value of t_so2 is less than 14, the UE can determine that the base station does not perform NC-JT-based transmission. That is, if the timeDurationForQCL required for applying the TCI state-related QCL parameter indicating the beamforming direction of the second PDSCH is not satisfied, the UE can skip the second PDSCH reception operation indicated in the second PDCCH.

[0444] Example 8-2

[0445] In the case where the UE receives a message from the base station in which the tci-PresentinDCI field is set to "enabled" and receives DCI format 1_1 through the first PDCCH or the second PDCCH, if the calculated scheduling time offset (t_so) value in one CORESET is less than the UE capability parameter timeDurationForQCL reported to the base station (e.g., S14), the UE may consider the following NC-JT-based transmission of the base station corresponding to Example 7-2. The UE may be configured with multiple CORESET groups. In an embodiment of the present disclosure, it is assumed that the first PDSCH is jointly allocated with the PDCCH in the CORESET in CORESET group #0, and the second PDSCH is jointly allocated with the PDCCH in the CORESET in CORESET group #1.

[0446] According to an embodiment of the present disclosure, when the value of t_so1 in the CORESET in CORESET group #0 is 14 or greater and the value of t_so2 in the CORESET in CORESET group #1 is less than 14, the UE may determine that the base station performs NC-JT-based transmission. That is, if the timeDurationForQCL required for applying the TCI state-related QCL parameter indicating the beamforming direction of the second PDSCH is not satisfied, the UE may apply the QCL parameter for receiving the N+1th PDCCH in the CORESET with the lowest CORESET ID (e.g., CORESET #1) associated with the monitored search space in the latest time slot based on the CORESET group (e.g., CORESET group #1) and the CORESET ID in which timeDurationForQCL is less than t_so2 when receiving the second PDSCH.

[0447] In an embodiment of the present disclosure, when the value of t_so1 in the CORESET in CORESET group #0 is 14 or greater and the value of t_so2 in the CORESET in CORESET group #1 is less than 14, the UE determines that the base station performs NC-JT based transmission. That is, when receiving the second PDSCH, the UE may apply a QCL parameter for receiving the Nth PDCCH in the CORESET with the lowest CORESET ID (e.g., CORESET #0) associated with the monitored search space in the latest slot in the lowest CORESET group (CORESET group #0) of the CORESET group (e.g., CORESET group #0 and CORESET group #1).

[0448] In an embodiment of the present disclosure, when the value of t_so1 in the CORESET in the CORESET group #0 is 14 or more and the value of t_so2 in the CORESET in the CORESET group #1 is less than 14, the UE determines that the base station performs NC-JT based transmission. That is, the UE may apply QCL parameters according to the beamforming direction indicated in the CORESET (e.g., CORESET #0) in the CORESET group (e.g., CORESET group #0) corresponding to a scheduling time offset equal to or less than timeDurationForQCL (i.e., information for the TCI field indicated in the second PDCCH) and the beam direction of the PDSCH (second PDSCH) scheduled in the CORESET (e.g., CORESET #1) in the CORESET group (e.g., CORESET group #1) corresponding to a scheduling time offset less than timeDurationForQCL. In this case, if the base station does not indicate a change in the beam direction in the first PDCCH, the second PDSCH may apply the QCL parameters of the first PDCCH (or the first PDSCH).

[0449] According to an embodiment of the present disclosure, the base station may compare t_so1 with timeDurationForQCL or compare t_so2 with timeDurationForQCL regardless of each CORESET group, and if t_so1 or t_so2 is less than timeDurationForQCL, the base station may not send a PDSCH (e.g., a second PDSCH) scheduled in a CORESET (e.g., CORESET#1) corresponding to a scheduling time offset less than timeDurationForQCL to a specific UE.

[0450] As another example, in a case where the UE receives a message in which the tci-PresentinDCI field is set to "enabled" from the base station and receives DCI format 1_1 through the first PDCCH or the second PDCCH, if the calculated scheduling time offset (t_so) value in one CORESET is less than the UE capability parameter timeDurationForQCL (e.g., S14) reported to the base station, the UE may consider the following NC-JT-based transmission of the base station corresponding to Example 7-2. Described below is a case in which CORESETs (e.g., CORESET group #0 (e.g., CORESET group #0 includes CORESET #0 to CORESET #4)) may be configured in the UE for the purpose of NC-JT, and beam change occurs in at least one of the PDSCHs transmitted jointly with the PDCCH in the CORESET. However, the present disclosure is not limited thereto, and the number of CORESETs configured in the UE may change according to the setting of the base station.

[0451] According to an embodiment of the present disclosure, the UE may apply a QCL parameter based on a CORESET ID corresponding to a scheduling time offset less than timeDurationForQCL in a configured CORESET group (e.g., CORESET group #0) when receiving a second PDSCH, and the QCL parameter is used to receive the Nth PDCCH in a CORESET with the lowest CORESET ID (e.g., CORESET #0) associated with the monitored search space in the latest time slot.

[0452] According to an embodiment of the present disclosure, the UE may apply a QCL parameter when receiving a second PDSCH, wherein the QCL parameter is used to receive the Nth PDCCH in a CORESET with a lowest CORESET ID (e.g., CORESET #0) associated with a monitored search space in the latest time slot in a lowest CORESET group (CORESET group #0) of a CORESET group (e.g., CORESET group #0).

[0453] According to an embodiment of the present disclosure, the UE may apply QCL parameters for NC-JT transmission according to the beamforming direction indicated in the CORESET (e.g., CORESET#0) corresponding to a scheduling time offset equal to or greater than timeDurationForQCL (i.e., information for the TCI field indicated in the second PDCCH), and the beamforming direction of the PDSCH (second PDSCH) scheduled in the CORESET (e.g., CORESET#1) corresponding to a scheduling time offset less than timeDurationForQCL. In this case, if the base station does not indicate a change in the beam direction in the first PDCCH, the QCL parameters of the first PDCCH (or the first PDSCH) may be applied to the second PDSCH.

[0454] According to an embodiment of the present disclosure, the base station may compare t_so1 with timeDurationForQCL or compare t_so2 with timeDurationForQCL regardless of each CORESET group used for NC-JT transmission, and if t_so1 or t_so2 is less than timeDurationForQCL, the base station may not send a PDSCH (e.g., a second PDSCH) scheduled in a CORESET (e.g., CORESET#1) corresponding to a scheduling time offset less than timeDurationForQCL to a specific UE.

[0455] In the above-described embodiments of the present disclosure, there is a CORESET group (for example, CORESET group #0 includes CORESET #0 and CORESET #2). However, in some cases, there may be no CORESET group, or no CORESET group is set and only CORESET exists. Therefore, it is obvious that the scheme in the above-described embodiments is performed based on the CORESET ID, except that there is no CORESET group or no CORESET group is set in the operation according to the above-described embodiments.

[0456] Although the above-described embodiments consider the lowest CORESET / CORESET group ID, the present disclosure may also encompass embodiments that consider the highest CORESET / CORESET group ID as well as the lowest CORESET / CORESET group ID.

[0457] Example 8-3

[0458] For example, when the tci-PresentinDCI field is not set to "enabled" or the UE receives DCI format 1_0 from the base station, the UE may receive multiple PDSCHs based on NC-JT transmission without considering the timeDurationForQCL reported by the UE capability report. That is, when receiving DCI format 1_0, the UE may assume that the base station has only transmitted one PDSCH allocated by one PDCCH. For example, the UE may determine that the beamforming direction of the first PDCCH is the same as the beamforming direction of the first PDSCH indicated by the first PDCCH, and the beamforming direction of the second PDCCH is the same as the beamforming direction of the second PDSCH indicated by the second PDCCH.

[0459] As another example, if the tci-PresentinDCI field is not set to "enabled", the UE may determine that PDSCH transmission based on NC-JT transmission is not supported.

[0460] Fig.14 13-50 shows an example in which the value of the duration (t_so1) between the last symbol of the first PDCCH and the start symbol of the first PDSCH and the value of the duration (t_so2) between the last symbol of the first PDCCH and the start symbol of the first PDSCH calculated by the UE are both 14 or greater, wherein the base station and the UE can operate according to at least one of the methods proposed below.

[0461] Example 9-1

[0462] For example, when the above conditions are met, that is, when the value of the duration (t_so1) between the last symbol of the first PDCCH and the start symbol of the first PDSCH and the value of the duration (t_so2) between the last symbol of the first PDCCH and the start symbol of the first PDSCH calculated by the UE are both 14 or greater, the base station can always set the tci-PresentinDCI field to "enabled" during NC-JT transmission. Alternatively, when the tci-PresentinDCI field is set to "enabled", the base station can set the scheduling time so that the above time conditions are always met during NC-JT transmission.

[0463] In the case where the tci-PresentinDCI field is set to "enabled" by the base station and DCI format 1_1 is received through the first PDCCH or the second PDCCH, if the scheduling time offset (t_so) value calculated by the UE is greater than or equal to the UE capability parameter timeDurationForQCL reported to the base station (e.g., S14), the UE applies the QCL assumption indicated by the TCI field in the PDCCH (or DCI) to the PDSCH DMRS port. For example, the UE can apply TCI state-related QCL parameters for the first PDSCH and the second PDSCH based on the TCI field information for each DCI in the first PDCCH and the second PDCCH to change the beamforming direction of the PDSCH. Even if the CORESET group is configured, the operations in Example 9-1 can be easily inferred and applied as described in conjunction with Example 8.

[0464] Example 9-2

[0465] For example, when the base station does not set the tci-PresentinDCI field to "enabled" or sends DCI format 1_0 to the UE, the base station may not perform scheduling for NC-JT transmission. Therefore, when the tci-PresentinDCI field is not set to "enabled" or when DCI format 1_0 is received from the base station, the UE may regard it as a base station that transmits only one PDSCH allocated by one PDCCH. For example, the UE may determine that the beamforming direction of the first PDCCH is the same as the beamforming direction of the first PDSCH indicated by the first PDCCH, and the beamforming direction of the second PDCCH is the same as the beamforming direction of the second PDSCH indicated by the second PDCCH.

[0466] In the above-mentioned embodiments of the present disclosure, the UE may desire to set one or more default QCLs in NC-JT transmission based on multiple PDCCHs within one CORESET.

[0467] Fig.15 is a flowchart illustrating a method of operating a UE according to an embodiment of the present disclosure.

[0468] Reference Fig.15 , a method for receiving PDSCH based on NC-JT transmission and default QCL assumption of UE.

[0469] In operation 15-00, the UE may receive at least one configuration information during an RRC establishment process with a base station, the configuration information including parameters related to base station beamforming (e.g., tci-PresentinDCI) and at least one of parameters or configuration information for control channels and data channels (e.g., PDDCH-config and PDSCH-config).

[0470] In addition, in operation 15-00, the UE may send UE capability information (e.g., timeDurationForQCL) to the base station. The UE may send the UE capability information at the request of the base station or at a predetermined time (e.g., during the RRC establishment process with the base station). Accordingly, when the base station receives the capability information of the UE, the operation of the base station receiving the capability of the UE may be omitted. Alternatively, the operation of the base station receiving the capability of the UE may be omitted according to the configuration information.

[0471] Thereafter, the UE receives the first PDCCH or the second PDCCH in a specific CORESET based on the configuration information from the base station.

[0472] In addition, in operation 15-10, the UE may identify at least one of resource allocation information, TCI-related information, and antenna port information of the first PDSCH or the second PDSCH based on the first PDCCH or the second PDCCH.

[0473] Based on the identified information, the UE may calculate a scheduling time offset between the PDCCH and the PDSCH (at least one between the first PDDCH and the first PDSCH or between the second PDCCH and the second PDSCH), and, in operations 15-20, based on the result of the calculation, the UE may determine at least one of a reception operation (or a reception operation method) of the first PDSCH or the second PDSCH or a reception beamforming direction of the first PDSCH or the second PDSCH. In this case, the operation of the UE determining the reception operation method of the first PDSCH or the second PDSCH may include at least one of the following: an operation of determining whether to receive data through at least one of the first PDSCH or the second PDSCH, or a method of receiving data through at least one of the first PDSCH or the second PDSCH when it is determined that data is received through at least one of the first PDSCH or the second PDSCH.

[0474] In operation 15-30, the UE may receive data via the first PDSCH or the second PDSCH corresponding to the first PDCCH or the second PDCCH based on at least one of the information identified in operation 15-10 and the determination result in operation 15-20.

[0475] The UE may decode the received data.

[0476] Table 16 shows a simplified Abstract Syntax Notation (ASN.1) structure of a serving cell. The following embodiments are described based on the high-level information elements and field information described in conjunction with Table 16 to distinguish between multiple TRPs for NC-JT-based transmission and configuration of multiple TRPs.

[0477] In Table 16, ServingCell can be mapped to each cell index by ServingCellIndex. Here, ServingCellIndex refers to the ID of the serving cell, and can be 0 when the serving cell is the primary cell (PCell) of the primary cell group, the value of servCellIndex set to SpCellConfig information element (IE) when the serving cell is a primary SCG cell (PSCell), or SCellIndex of SCellConfig IE when the serving cell is a secondary cell (SCell).

[0478] Further, physCellId indicates the physical cell identifier of the serving cell, and the corresponding cell identifier can be the value set in the ServingCellConfigCommon IE. Transmission resource configuration, such as the downlink transmission channel related configuration of the serving cell and BWP, can be defined by IE, such as absolute radio frequency channel number (ARFCN), PDSCH-ServingCellConfig, BWP, PDCCH-Config, PDSCH-ConFIG. Similarly, the uplink transmission related components of the corresponding serving cell can be defined by IE, such as ARFCN, PUSCH-ServingCellConfig, BWP, PUCCH-Config, PUSCH-ConFIG. For multi-TRP transmission based on NC-JT, TRP pairs or TRP sets can be configured according to the parameters or IEs of Table 16.

[0479] For example, for multi-TRP transmission based on NC-JT, TRP pairs or TRP sets can configure or classify TRPs in units of ServingCell IE. In this case, when TRPs are classified based on each ServingCell, NC-JT-based transmission can constitute a pair or a group of different ServingCells, and additional combinations and changes can be made if changes are required. That is, multiple base stations can be operated, with each TRP mapped to a different ServingCell object. In addition, ServingCell pairs or ServingCell sets can be configured, and separate higher-layer parameters can be configured. Here, multiple TRPs for NC-JT can have the same SSB carrier or SCS-SpecificCarrier. In addition, multiple TRPs can include the same SCS, the same carrier BW, and the same A-point (a common reference point of the resource block grid or the lowest subcarrier of the common RB 0).

[0480] As another example, for multi-TRP transmission based on NC-JT, TRP pairs or TRP sets can configure or classify TRPs in units of PDCCH-config. In this case, since multiple TRPs have been configured with the same ServingCell, the UE can determine that multiple TRPs are the same cell. If the base station configures a TRP pair or TRP set for NC-JT according to the PDDCH-config, the UE can determine the configuration and change of the TRP through the configuration and change of the PDCCH-config through the RRC configuration or reconfiguration process. That is, at least two or more TRPs can set multiple CORESETs and search spaces through PDCCH-config, and different scrambling IDs or different time / frequency resources can be additionally allocated. In this case, each PDCCH configuration can use up to 5 CORESETs for URLLC purposes, and independent TCI states can be set for PDCCH diversity performance.

[0481] As another example, for multi-TRP transmission based on NC-JT, TRP pairs or TRP sets can configure or classify TRPs in units of CORESET or CORESET groups. In this case, since multiple TRPs have been configured with the same ServingCell, the UE can determine that multiple TRPs are the same cell. If the base station configures TRP pairs or TRP sets for NC-JT in units of CORESET or CORESET groups, the UE can determine the configuration and change of the TRP through the configuration and change of PDCCH-config CORESET (index) or CORESET group (index) through the RRC configuration or reconfiguration process. That is, for the transmission of at least two or more TRPs, the CORESET indexes can be associated with each other, or the CORESETs of the TRPs can operate in association with each other using the CORESET group index set on each CORESET.

[0482] The maximum number of CORESETs that can be set in the same TRP can be determined by the capabilities of the UE, and the base station can set the candidate for the maximum number of CORESETs to 3 to a minimum value or 5 (for example, in the case of a URLLC scenario) to a maximum value in consideration of the capability value of the UE. Further, the maximum number of CORESET groups (indexes) supported by the UE can be set to be less than or equal to the maximum number of CORESETs set in the UE. A UE supporting NC-JT in Rel-16 supports up to two CORESET groups. The UE can store the set CORESET groups (indexes) in a memory according to the capability value of the UE and manage them accordingly.

[0483] When a higher layer index is set for each CORESET, in case of multi-DCI based operation, if multiple dataScramblingIdentityPDSCH parameters are set, each dataScramblingIdentityPDSCH is associated with the higher layer index of each CORESET and applies to the PDSCH that has scheduled the DCI identified in the CORESET with the same higher layer index.

[0484] [Table 16]

[0485]

[0486] Various embodiments of the present disclosure describe operations for determining a default QCL in a base station and a UE. In the description of the above various embodiments, the case where the beam used to send PDCCH and the beam used to transmit PDSCH are the same has been considered. At the same time, depending on the settings in the TRP, the TRP can be configured (decoupled) so that the PDCCH beam (the beam that sends PDCCH) and the PDSCH beam (the beam that sends PDSCH) are different from each other. Such examples may include when the PDCCH beam and the PDSCH have different beam widths, for example, when the width of the PDCCH beam is wider and the width of the PDSCH beam is narrower, or when different beams or adjacent beams are set although their beam widths are the same. At least two or more beam widths operated by the base station can be set (for example, level 1: wide beam; level 2: normal beam; level 3: narrow beam, etc.), and in this case, the base station can mainly set and use wide beams, such as level 1, for beams used to send PDSCH, and set and use narrow beams of level 2 or 3 as well as level 1 for UEs that require increased throughput.

[0487] In this way, although the beam used by the TRP for transmitting the PDCCH and the beam used by the TRP for transmitting the PDSCH are set to be different from each other, the UE can perform the PDSCH reception operation in a manner similar to the method specified in Rel-15. For example, if the scheduling time offset (t_so) value calculated from the time when the control information including the information that the PDSCH is allocated via the CORESET is received to the time when the allocated PDSCH is received is less than the UE capability parameter timeDurationForQCL reported to the base station (e.g., 14 symbols), the UE can apply the QCL assumption (i.e., the same QCL parameters) of the lowest CORESET ID in the latest listening time (time slot or opportunity) when receiving the PDSCH.

[0488] However, the above embodiment can be applicable to a context in which the beams for sending different PDCCHs are the same as the beams for sending PDSCH. If the base station sets the beam for sending PDCCH and the beam for sending PDSCH to be different from each other in order to improve throughput, when t_so is less than timeDurationForQCL, the UE can use the default spatial QCL for PDSCH reception, and in the present disclosure, a method for determining the default spatial QCL is proposed.

[0489] Example A1

[0490] The base station and the UE can set the beam to be applied to the default QCL via signaling based on the MAC CE. The UE can identify the default (spatial) QCL related information of the MAC CE received from the base station and apply the identified information to the operation of receiving the PDSCH. That is, the UE can receive the MAC CE from the base station and identify the information related to the default QCL. If the received t_so value between the PDCCH and the PDSCH is less than the timeDurationForQCL, the UE can apply the information related to the default QCL for PDSCH reception set in the MAC CE to the beam for receiving the PDSCH and receive the PDSCH. In this case, the default QCL related information may include at least one of the QCL parameters, the TCI state related information, and the information associated with the DL-RS or UL-RS.

[0491] For the MAC CE structure configured by the base station, at least one MAC CE structure discussed in Rel-15 / 16 may be (re)used and (re)interpreted.

[0492] As an example, if Fig. 10A 10-00 of , the UE receives a TCI state activation / deactivation MAC CE message for a PDSCH based on Rel-15 as in , the UE can determine that the beam indicated as the default QCL of the PDSCH and the beam for sending the PDCCH are set to be different from each other. Specifically, after receiving the TCI state activation / deactivation message, the UE can understand one of the activated TCI states as the TCI state corresponding to the default QCL according to a predetermined rule. For example, the TCI state corresponding to the default QCL according to the predetermined rule can be defined as the TCI state indicated by the lowest / highest index in the activated TCI state in the MAC CE message. After receiving a MAC CE message in which the service cell ID#2, BWP#4, and T0 to T7 values ​​are all indicated as the activated state (1), the UE can determine that the TCI state corresponding to the default QCL in the service cell #2 and BWP#4 is the lowest TCI index (T0) or the highest index (T7) in the activated TCI index.

[0493] As another example, Fig. 10AAs shown in 10-50 of , the UE can receive a TCI state indication MAC CE message for a PDCCH based on Rel-15, and understand the TCI state ID indicated in the message together with CORESET 0 as the TCI state corresponding to the default QCL of the beam used to send the PDSCH. Here, the TCI state ID of the MAC CE message refers to the ID of the TCI state of the PDSCH set in a higher layer (for example, the TCI state ID included in tci-States-ToAddModList). That is, the UE can receive the TCI state indication MAC CE of the PDCCH from the base station and identify the information related to the default QCL. If the received t_so value of the PDCCH and the PDSCH is less than timeDurationForQCL, the UE can apply the TCI state indicated together with CORESET 0 for PDSCH reception to the beam receiving the PDSCH. As a result, when the UE receives a PDSCH scheduled via a PDCCH transmitted in CORESET0, the default QCL beam of the PDSCH can be the same as the beam set for CORESET 0. Meanwhile, if the beam for CORESET 0 is not set as the MAC CE, the default beam for receiving the PDSCH may be a preset TCI state as in the various embodiments described above.

[0494] As another example, if a portion of the beam list for PDCCH reception set in the UE (e.g., the beam list set and released by tci-StatesPDCCH-ToAddList and tci-StatesPDCCH-ToReleaseList) is set as a duplicate of the beam list for PDSCH reception (e.g., the beam list set and released by tci-StatesToAddModList and tci-StatesToReleaseList), the base station and the UE can exclude the duplicate beam when setting the default QCL for PDSCH reception. That is, the UE can compare the reference RS and QCL type of each beam configured for PDCCH reception with the reference RS and QCL type of each beam configured for PDSCH reception, and if there are duplicate reference RS and QCL types in the PDCCH reception beam list and the PDSCH reception beam list, the UE can exclude the duplicate from the default QCL configuration for PDSCH reception. Alternatively, the UE does not want to set the beam that can be reused for PDCCH reception and PDSCH reception as the default QCL for PDSCH reception.

[0495] The MAC CE structure set by the base station may consist of a new control element message (signaling) structure.

[0496] A new message may be configured in the form of a default QCL for setting a message for supporting a single TRP. For example, a MAC CE message for setting the default QCL may include information (e.g., a TCI index) indicating at least one TCI state assumed by the default QCL of the PDSCH. As another example, the message may directly or indirectly indicate the direction of a beam sent from the base station using information such as QCL type A / B / C / D or DL-RS / UL-RS index. This information refers to the beam direction assumed by the base station and the UE for PDSCH reception when there is insufficient time for the UE to decode the DCI including beam information for PDSCH reception sent by one TRP or when there is insufficient time for the UE to switch beams and receive the PDSCH.

[0497] The message may be configured in the form of a message for setting a default QCL for supporting multiple TRPs. For example, a MAC CE message for setting the default QCL may include information indicating at least one TCI state assumed by the default QCL of the PDSCH (e.g., TCI index #1 or TCI index #2). In this case, if the message includes one TCI state, the UE may determine that multiple TRPs indicate the same default QCL or a single TRP indicates one default QCL, and if the message includes two or more TCI states that are different from each other, the UE may determine that multiple TRPs indicate two or more different default QCLs. Specifically, if the message indicates two or more TCI indexes, the UE may determine the order of the TCI indexes according to the order of the TRPs or the order of the HigherLayerIndexPerCORESET indexes. Alternatively, the TRP index / HigherLayerIndexPerCORESET index and the corresponding TCI index may be indicated respectively. Further, when the message may include two or more TCI states and the indicated TCI states are the same, the UE may determine that the same default QCL is indicated.

[0498] As another example, the MAC CE message for setting the default QCL may include information (e.g., a TCI set index) indicating at least one TCI set (e.g., a pair of two or a group of three) among the TCI states assumed for the default QCL of the PDSCH transmitted from the multi-TRP. In this case, upon receiving the TCI set index, the UE can determine that the multi-TRP has indicated a pre-specified TCI state as the default QCL.

[0499] As another example, the message may directly or indirectly indicate the direction of the beam transmitted from the base station using information such as multiple QCL types A / B / C / D or DL-RS / UL-RS indexes. This information refers to the beam direction assumed by the base station and the UE for receiving the PDSCH when the UE performs beam switching on the PDSCH transmitted from one TRP and the time for receiving the PDSCH is insufficient.

[0500] Alternatively, separate messages can be set up for single-TRP and multi-TRP, or a single integrated message configured as one type can be set up.

[0501] As an example, a MAC CE message for setting a default beam based on multiple TRPs can be set separately for multiple TRPs based on a single DCI. As another example, a MAC CE message for setting a default beam based on multiple TRPs can be set separately for multiple TRPs based on multiple DCIs.

[0502] In addition, separate messages for single TRP and multiple TRPs can be determined based on the TRP sending / receiving capabilities supported by the UE. Further, MAC CE can be used to set the initial default QCL and can be considered as further updated.

[0503] Example A2

[0504] The MAC CE message can be configured per component carrier (CC) or per BWP.

[0505] First, the MAC CE message may be configured as a CC unit. As an example, the MAC CE message may indicate the default QCL related information applied in one CC (e.g., primary CC / PCell / PSCell, secondary CC / SCell, or cross-CC) and the activated BWP. As another example, the MAC CE message may indicate the default QCL related information applied in one CC and at least one or more configured BWPs. As another example, the MAC CE message may indicate the default QCL related information applied in one CC and all BWPs supported by the CC.

[0506] Second, the MAC CE message may be configured for multiple CCs at the same time. As an example, the MAC CE message may indicate the default QCL related information applied in at least two or more CCs (e.g., including a primary CC / PCell / PSCell, a secondary CC / SCell, or cross-CC) and an activated BWP. As another example, the MAC CE message may indicate the default QCL related information applied in at least two or more CCs and at least one or more configured BWPs. As another example, the MAC CE message may indicate the default QCL related information applied in at least two or more CCs and all BWPs supported by the CC.

[0507] Third, in the above embodiments of the present disclosure, a MAC CE message may be configured for each CC combination and / or each BWP combination set in the UE. Specifically, a factor indicating some or all of the preset CCs / activated CCs may be set through higher layer signaling in the MAC CE message. The CC indication factor may indicate at least one of the following as shown in Table 17.

[0508] [Table 17]

[0509]

[0510] The MAC CE message may include the default QCL related information applied to the CC indicated above. In addition, the MAC CE message may be applied to all BWPs / activated BWPs / BWP sets in the indicated CC. Here, the BWP set may be explicitly indicated or may be implicitly agreed upon, and when explicitly indicated, it may be indicated by a higher layer configuration or MAC CE.

[0511] Fourth, in the above-mentioned embodiments of the present disclosure, the MAC CE message may be configured or further updated when switching a CC or a BWP. Specifically, the MAC CE message may indicate the default QCL-related information of each BWP when CC switching occurs, such as when an additional CC is activated for the UE or when a connected CC is deactivated and a new CC is activated. For example, the MAC CE message may indicate the default QCL-related information applied in the switched or updated CC and the activated BWP, and the CC currently communicating between the UE and the base station. As another example, the MAC CE message may indicate the default QCL-related information applied in the switched or updated CC and at least one or more configured BWPs. As another example, the MAC CE message may indicate the default QCL-related information applied in the switched or updated CC and all BWPs supported by the CC.

[0512] Example A3

[0513] The method of specifying and updating beams for the default QCL based on the MAC CE message can be effectively used starting from the time when the MAC CE mesh structure is set. For example, after the UE's initial access process, the base station does not activate the duration of the default QCL configuration-related MAC CE message. The duration may include a period during which the default QCL configuration-related MAC CE message is not received and a predefined period from the time the UE receives the MAC CE message to the time the MAC CE is activated. After receiving the PDSCH before and after the duration, the default QCL can be set as follows.

[0514] First, the UE can determine that the beam that transmits the PDCCH and the beam that transmits the PDSCH transmitted from the base station are the same until the MAC CE message for setting the default QCL related information transmitted from the base station is activated. If the scheduling time offset (t_so) value calculated from the reception time of the CORESET including the PDCCH for allocating the PDSCH to the reception time of the allocated PDSCH is less than the UE capability parameter timeDurationForQCL reported to the base station (e.g., 14 symbols), the UE can apply the QCL assumption of the lowest CORESET ID in the latest listening time (time slot or opportunity) when receiving the PDSCH. Alternatively, when the condition is met, the UE can apply the QCL assumption of the lowest CORESET ID in the latest listening time (time slot or opportunity) in the CORESET group that transmits the PDCCH for allocating the PDSCH when receiving the PDSCH. When the MAC CE message for setting the default QCL configuration of the PDSCH is activated in a specific CC or BWP but the MAC CE message is not activated in the remaining CCs or BWPs, the above operation can also be applied to the inactivated CC or BWP.

[0515] Second, after the MAC CE message for setting the default QCL related information sent from the base station is activated, the UE can receive the PDSCH based on the default QCL related information set in the MAC CE message as described above in combination with Embodiments 1 and 2. That is, if the scheduling time offset (t_so) value calculated from the reception time of the control information for allocating the PDSCH through the CORESET to the reception time of the allocated PDSCH is less than the UE capability parameter timeDurationForQCL reported to the base station (e.g., 14 symbols), the UE can apply the QCL parameters to receive the PDSCH based on the QCL related information indicated in the MCE CE.

[0516] Third, if after receiving a MAC CE message for setting default QCL related information sent from a base station, the code point value of the transmission configuration indication (TCI) field is indicated in DCI format 1_1, the UE can receive the PDSCH based on the default QCL related information set in the MAC CE message as described above in combination with Embodiment A1 and Embodiment A2. The TCI field can be applied to the case where the higher layer parameter tci-PresentInDCI is enabled.

[0517] Fourth, if the base station does not set the higher layer parameter tci-PresentInDCI to enabled or changes it to disabled for the UE, the UE may not expect the default QCL configuration based on the MAC CE message. Alternatively, if the base station does not set the higher layer parameter tci-PresentInDCI to enabled for the UE, the UE may not apply the default QCL related information indicated in the MAC CE when receiving the PDSCH, although the MAC CE message for setting the default QCL sent from the base station is received. As a result, if the scheduling time offset (t_so) value calculated from the reception time of the control information for allocating the PDSCH by the CORESET to the reception time of the allocated PDSCH is less than the UE capability parameter timeDurationForQCL reported to the base station (e.g., 14 symbols), the UE may apply the QCL assumption applied to the lowest CORESET ID in the latest listening time (time slot or opportunity) when receiving the PDSCH. Alternatively, when the conditions are met, the UE may apply the QCL assumption applied to the lowest CORESET ID in the latest listening time (time slot or opportunity) in the CORESET group transmitting the PDCCH for allocating the PDSCH when receiving the PDSCH.

[0518] Fifth, if the base station performs cross-carrier scheduling or cross-BWP scheduling on PDSCH and does not set the PDSCH default QCL through MAC CE in a specific CC or BWP, the UE can perform the same operation as before the MAC CE message activation in the specific CC or BWP.

[0519] For example, if the scheduling time offset (t_so) value calculated from the reception time of the control information for scheduling the PDSCH allocated across carriers or across BWPs by the CORESET to the reception time of the PDSCH allocated across carriers or across BWPs is less than the UE capability parameter timeDurationForQCL reported to the base station (e.g., 14 symbols), the UE can apply the QCL assumption applied to the lowest CORESET ID in the latest listening event (time slot or opportunity) when receiving the PDSCH. That is, the same QCL parameters. Alternatively, if the scheduling time offset (t_so) value calculated from the reception time of the CORESET in the CORESET group including the PDCCH that schedules the PDSCH allocated across carriers or across BWPs to the reception time of the PDSCH allocated across carriers or across BWPs is less than the UE capability parameter timeDurationForQCL reported to the base station (e.g., 14 symbols), the UE may apply the QCL assumption of the lowest CORESET ID in the latest listening event (time slot or opportunity) in the CORESET group in which the PDCCH in which the PDSCH is allocated when receiving the PDSCH, i.e., the same QCL parameters.

[0520] Fig.11 , 16 1 to 18 show an example of multiple TRPs transmitting multiple PDSCHs to a specific UE through a single PDCCH according to various embodiments of the present disclosure. Here, various schemes may exist according to aspects of the PDSCHs allocated to the UE by the TRP. The scheme according to PDSCH transmission can be divided as follows.

[0521] Solution 1 (Spatial Domain Multiplexing (SDM)): The base station uses the number of nodes less than N in a single time slot. s (The maximum number of supportable TCI states) n TCI states is a scheme for allocating PDSCHs to a UE, where the transmitted PDSCHs overlap in the time and frequency domains.

[0522] Solution 2 (Frequency Domain Multiplexing (FDM)): The base station is based on less than N f (The maximum number of supportable TCI states) n TCI states is a scheme for allocating PDSCHs to a UE, where the PDSCHs do not overlap in the frequency domain.

[0523] Solution 3 (Time Domain Multiplexing (TDM)): The base station uses a t1 (The maximum number of supportable TCI states) n TCI states is a scheme for allocating PDSCHs to the UE, where the transmitted PDSCHs do not overlap in the time domain.

[0524] Solution 4 (Time Domain Multiplexing (TDM)): The base station uses multiple single time slots less than Nt2 The n TCI states (the maximum number of supportable TCI states) are a scheme for allocating PDSCHs to a UE, where the transmitted PDSCHs overlap in the time and frequency axes (domains).

[0525] In scheme 3 or 4, in the case of 3GPP Rel-16, the maximum number of TCI states can be, for example, 2 or more. In addition, the TRP can support the same number of consecutive symbols in one transmission. For example, if the first PDSCH sent to the UE includes two symbols, the second and subsequent PDSCHs can both include two symbols. In addition, the maximum number of layers transmitted by each TRP can be at least two or more. The maximum size of the supported TB can be determined based on the capabilities of the UE.

[0526] In scheme 3, the number of times the PDSCH is sent can be determined by the number of TCI states indicated in the code point of the TCI field in the DCI. For example, if the number of states in the TCI field in the DCI received from the UE is determined to be 1, it means that the PDSCH allocated by the base station is transmitted once, and if it is 2, it means that the PDSCH is transmitted twice. In this case, in the first PDSCH transmission and the second and subsequent PDSCH transmissions, the offset value Koffset can be set to indicate the offset of a predetermined number of symbols or the offset between PDSCHs in the time domain. For example, the first symbol in the second transmission can be allocated Koffset symbols away from the last symbol in the first transmission. In this case, Koffset can be set by the relevant RRC parameters, in which case the UE regards Koffset as 0 unless otherwise set in the RRC.

[0527] In scheme 4, the base station can indicate to the UE the number of times the PDSCH is sent by using the PDSCH-TimeDomainResourceAllocation field for time domain resource allocation (TDRA). In this case, as a method for indicating PDSCH resource allocation, information of the SLIV field indicating, for example, the starting position, length, and offset of the PDSCH symbol can be directly or indirectly utilized. Further, the SLIV value applied to the first PDSCH allocated by the base station can also be applied to multiple PDSCHs in the second transmission or its subsequent transmissions.

[0528] The RVid indicated by the DCI can indicate the selection of a redundancy version (RV) sequence. The base station sends data according to the set RVid. In this case, the base station has the same RVid. id The data is the same. Generally speaking, the RV transmission sequence is repeated four times by default. In each transmission, RV can be transmitted idThe RV sequence sent from each TRP can be defined as follows.

[0529] -The selected RV sequence is linked to the first TRP (first TCI state), and the RV sequence linked to the second TRP is determined by the RV offset from the selected RV sequence.

[0530] -RV offset is determined by the set RRC value

[0531] - TCI state mapping for PDSCH transmission supports 2 options and switching is determined by RRC

[0532] - Option 1: Round Robin Mapping (if 2 TCI states are indicated, map to #1#2#1#2)

[0533] - Option 2: Sequential mapping (if 2 TCI states are indicated, map to #1#1#2#2)

[0534] Fig.16 , 17 and 18 are diagrams showing a process for sending multiple PDSCHs from multiple TRPs to a specific UE via a single PDCCH according to various embodiments of the present disclosure.

[0535] Reference Fig.16 , 17 and 18, Fig.16 -00, 17-00 and 18-00 correspond to the case where the Koffset between multiple PDSCHs allocated to the UE by the base station based on scheme 3 or 4 is 0. Specifically, the base station can send the first PDCCH and the first and second PDSCHs corresponding thereto to the UE, and in some cases, the second PDCCH and the first to fourth PDSCHs corresponding thereto can be sent continuously or after a predetermined time. The UE can receive multiple PDSCHs and send HARQ ACK / NACK to PUCCH#1 and #2 indicated in the PDCCH set by the base station according to whether the decoding is successful. Multiple PDSCHs scheduled in a single PDCCH can repeatedly transmit the same data (for example, when the indicated RV value is the same).

[0536] Modification 1-1

[0537] Specifically, the number of TCI states sent by TRP or the number of TRPs sending PDSCH can be the same as the number of PDSCHs repeatedly sent in mode 1.

[0538] Here, Mode 1 is as follows.

[0539] - Mode 1: TCI state number (TRP number) = number of repetitions

[0540] (Mode 1: TCI state number (TRP number) = number of repetitions)

[0541] For example, the UE recognizes that the TCI state {#1, #2, #3, #4} is indicated by the TCI code point within the DCI, and it can be recognized as indicated in 16-00, indicating that it applies TCI state #1 to the first PDSCH, applies TCI state #2 to the second PDSCH, applies TCI state #3 to the third PDSCH, and applies TCI state #4 to the fourth PDSCH. The UE that recognizes the DCI in this way can determine the direction of the reception beam through the following determination process as to whether to apply the indicated state.

[0542] First, if the number of TCI states indicated by the TCI in the DCI from the base station is the same as the number of PDSCHs transmitted repeatedly, the position of the time domain resources of the PDSCH to which the TCI state is applied is compared with timeDurationForQCL to determine whether the TCI state is applied.

[0543] For example, if the time when the TCI state is applied to the PDSCH is after the position based on the set timeDurationForQCL, the UE can allocate all TCI state information indicated in the DCI to the PDSCH in sequence. That is, if the transmission time (start time) of the PDSCH scheduled to apply the TCI state is equal to or greater than symbol No. 9, the UE that recognizes that the last symbol index of the PDCCH transmitted from the base station is 2 and the set timeDurationForQCL value is 7 can perform reception, in which TCI state #1, TCI state #2, TCI state #3 and TCI state #4 are applied to the first PDSCH, the second PDSCH, the third PDSCH and the fourth PDSCH in sequence.

[0544] As another example, if the transmission time (start time) of the PDSCH scheduled to apply the TCI state is equal to or greater than the first symbol of the next time slot, a UE that recognizes that the last symbol index of the PDCCH sent from the base station is 2 and the timeDurationForQCL value is set to 14 can perform reception, where TCI state #1, TCI state #2, TCI state #3 and TCI state #4 are applied to the first PDSCH, the second PDSCH, the third PDSCH and the fourth PDSCH respectively.

[0545] Modification 1-2

[0546] If the time when the TCI state is applied to the PDSCH is before the position based on the set timeDurationForQCL, the UE that receives multiple PDSCHs indicating the TCI state from the base station does not completely and sequentially allocate all TCI state information indicated in the DCI to the PDSCH.

[0547] For example, if at least one symbol of a first PDSCH (e.g., a first PDSCH) among multiple PDSCHs exists in a position based on timeDurationForQCL, a UE that receives multiple PDSCHs in which TCI states are indicated from a base station may apply a default spatial QCL instead of TCI state #1 indicated in the first PDSCH. The default spatial QCL refers to a QCL parameter for receiving a PDCCH in a CORESET with the lowest CORESET ID associated with the monitored search space in the latest time slot. In addition, the UE may perform reception in which TCI state #2, TCI state #3, and TCI state #4 are applied to the second PDSCH, the third PDSCH, and the fourth PDSCH, respectively, in sequence. That is, although the base station instructs the UE to apply TCI state #1 to the first PDSCH as in 16-30, if the starting symbol of the first PDSCH is symbol number 4 and the symbol length is 5, the UE that recognizes that the last symbol index of the PDCCH is 2 and timeDurationForQCL is 7 can apply the default spatial QCL to the first PDSCH, and apply TCI state #2 to TCI state #4 indicated in the TCI in the DCI to other PDSCHs, i.e., the second PDSCH to the fourth PDSCH, thereby performing beamforming for PDSCH reception.

[0548] As another example, if at least one symbol of a second PDSCH (e.g., a second PDSCH) among a plurality of PDSCHs exists in a position based on timeDurationForQCL, a UE receiving a plurality of PDSCHs in which TCI states are indicated from a base station may apply a default spatial QCL instead of TCI states #1 and #2 indicated in the first PDSCH and the second PDSCH. The default spatial QCL refers to a QCL parameter for receiving a PDCCH in a CORESET with the lowest CORESET ID associated with the monitored search space in the latest time slot. In addition, the UE may perform reception in which TCI state #3 and TCI state #4 are applied to the third PDSCH and the fourth PDSCH, respectively, in sequence. That is, although the base station instructs the UE to apply TCI states #1 and #2 to the first and second PDSCHs, if the starting symbol of the first PDSCH is symbol No. 5 and the symbol length is 3, the UE that recognizes that the last symbol index of the PDCCH is 2 and timeDurationForQCL is 7 can apply the default spatial QCL to the first and second PDSCHs and apply TCI state #3 and TCI state #4 indicated in the TCI in the DCI to other PDSCHs, namely the third PDSCH and the fourth PDSCH, thereby performing beamforming for PDSCH reception.

[0549] The default spatial QCL can be extended to have the following meanings.

[0550] 1) The above meaning, that is, the QCL parameter is used to receive the PDCCH in the CORESET with the lowest CORESET ID associated with the monitored search space in the latest time slot.

[0551] 2) The default spatial QCL of the PDSCH set by, for example, MAC-CE. In this case, the same default spatial QCL can be set for all TRPs, or a different default spatial QCL can be set for each TRP.

[0552] 3) The default spatial QCL of the PDSCH may indicate a value having the lowest ID in a TCI state for the PDSCH set by the RRC or a value having the lowest ID in a TCI state for the PDSCH activated by the MAC-CE.

[0553] Different default spatial QCLs may be applied depending on the context. For example, in the case of cross-carrier scheduling or cross-BWP scheduling, 3) may be applied, while in other cases, 1) or 2) may be applied. In the case where the UE supports MAC-CE for configuring a default spatial QCL for PDSCH, 1) may be applied before activating the corresponding MAC-CE, and 2) may be applied thereafter.

[0554] Modification 1-3

[0555] As another example, if the starting positions of all repeated PDSCHs are less than timeDurationForQCL, a UE that receives a PDSCH indicating a TCI state from a base station in time slot 0 / 1 such as 16-00, particularly in scheme 3, can apply a default spatial QCL instead of the TCI state indicated for the first PDSCH and the second PDSCH or the first to fourth PDSCHs. Here, one, two, or four default QCLs can be set and run based on a single PDCCH default QCL enhancement. That is, although the base station instructs the UE to apply TCI state #1 to TCI state #4 to the first to fourth PDSCHs in time slot 1, if the starting symbol of the first PDSCH is symbol No. 4 and the symbol length is 1, the UE that recognizes that the last symbol index of the PDCCH is 2 and timeDurationForQCL is 7 can apply the default spatial QCL to the first to fourth PDSCHs, because the symbol index of the starting position of all repeated multiple PDSCHs is less than the symbol index (No. 9) at the position taking into account timeDurationForQCL. In this case, one, two, or four default QCLs may be set or determined, and the PDSCH may be received by applying them.

[0556] Modification 1-4

[0557] If the time at which the TCI state is applied to the PDSCH is before the position at which the time at which the PDSCH is applied is set based on timeDurationForQCL, a UE that receives multiple PDSCHs indicating the TCI state from a base station can apply the default spatial QCL to the first to fourth PDSCHs instead of the TCI state indicated for the first to fourth PDSCHs, regardless of whether the PDSCH positions overlap.

[0558] Modification 2

[0559] As an example, if at least one symbol of the first PDSCH among multiple PDSCHs exists in a position based on timeDurationForQCL, a UE that receives multiple PDSCHs in which TCI states are indicated from a base station can apply a default spatial QCL instead of applying TCI state #1 indicated in the first PDSCH, and can apply TCI state #1, TCI state #2, and TCI state #3 to the second PDSCH, the third PDSCH, and the fourth PDSCH, respectively, in sequence when performing reception. That is, although the base station instructs the UE to apply TCI state #1 to the first PDSCH as in 16-30, if the starting symbol of the first PDSCH is symbol No. 4 and the symbol length is 5, the UE that recognizes that the last symbol index of the PDCCH is 2 and timeDurationForQCL is 7 can apply the default spatial QCL to the first PDSCH and apply TCI state #2 to TCI state #4 indicated in the TCI in the DCI to other PDSCHs, i.e., the first PDSCH to the third PDSCH, thereby performing beamforming for PDSCH reception. Therefore, the base station can change and indicate TCI-related information in the DCI under the premise of considering the default QCL of the UE. That is, the base station can predict the default QCL in which the UE operates and indicate {#1,#2,#3}, {#1,#2} or {#1} for the TCI state under the premise of considering the default QCL, instead of {#1,#2,#3,#4}. In this case, the base station can virtualize the TCI field or the TCI state-related higher-layer parameter field.

[0560] Fig.16 16-60 show examples in which Koffset between multiple PDSCHs allocated to the UE by the base station in various embodiments of variant examples 1 and 2 is not zero (for example, when Koffset is set to 2). Here, as a condition for changing Koffset, if the position based on timeDurationForQCL in the time domain exists in an offset region located between PDSCHs, the UE can regard the PDSCH that existed before the offset as a region for determining whether to apply the default QCL. For example, if the transmission time (start time) of the PDSCH scheduled to apply the TCI state is equal to or greater than symbol No. 9, a UE that recognizes that the last symbol index of the PDCCH sent from the base station is 2 and the set timeDurationForQCL value is 7 can perform reception, in which TCI state #1, TCI state #2, TCI state #3 and TCI state #4 are applied to the first PDSCH, the second PDSCH, the third PDSCH and the fourth PDSCH, respectively.

[0561] As another example, although the base station instructs the UE to apply TCI state #1 to the first PDSCH, if the starting symbol of the first PDSCH is symbol number 4, the symbol length is 4, and Koffset is 2, the UE that recognizes that the last symbol index of the PDCCH is 2 and timeDurationForQCL is 7 can additionally recognize that timeDurationForQCL exists in the offset region between the first PDSCH and the second PDSCH or before the second PDSCH, and applies the default spatial QCL to the first PDSCH, while applying the above-mentioned embodiments (variants 1 to 2) to other PDSCHs, i.e., the second PDSCH to the fourth PDSCH.

[0562] As another example, if the starting positions of all repeated PDSCHs are less than timeDurationForQCL, a UE that receives a PDSCH indicating a TCI state in time slot 0 / 1 from a base station as in 17-00 (specifically, Scheme 3) can apply a default spatial QCL instead of the TCI state indicated for the first PDSCH and the second PDSCH or the first to fourth PDSCH. Here, one or two default QCLs can be set and run based on a single PDCCH default QCL enhancement. That is, although the base station instructs the UE to apply TCI state #1 and TCI state #2 to the first to fourth PDSCHs in time slot 1, if the starting symbol of the first PDSCH is symbol No. 4 and the symbol length is 1, the UE that recognizes that the last symbol index of the PDCCH is 2 and timeDurationForQCL is 7 can apply the default spatial QCL to the first to fourth PDSCHs, because the symbol index of the starting position of all repeated multiple PDSCHs is less than the symbol index (No. 9) considering the position of timeDurationForQCL. In this case, two default QCLs may be set or determined, and the PDSCH may be received by applying them.

[0563] The default spatial QCL can be extended to have the following meanings.

[0564] 1) The above meaning is that the QCL parameter is used to receive the PDCCH in the CORESET with the lowest CORESET ID associated with the monitored search space in the latest time slot.

[0565] 2) Default spatial QCL for PDSCH set by, for example, MAC-CE. In this case, the same default spatial QCL may be set for all TRPs, or a different default spatial QCL may be set for each TRP.

[0566] 3) The default spatial QCL of the PDSCH may indicate a value having the lowest ID in a TCI state for the PDSCH set by the RRC or a value having the lowest ID in a TCI state for the PDSCH activated by the MAC-CE.

[0567] Different default spatial QCLs may be applied depending on the context. For example, in the case of cross-carrier scheduling or cross-BWP scheduling, 3) may be applied, and in other cases, 1) or 2) may be applied. In the case where the UE supports MAC-CE for configuring a default spatial QCL for PDSCH, 1) may be applied before activating the corresponding MAC-CE, and 2) may be applied thereafter.

[0568] Modification 3, Modification 4

[0569] First, if Fig.17 and 18 As shown, the number of TCI states sent by multiple TRPs or the number of TRPs sending PDSCH can be less than the number of PDSCHs repeatedly sent in mode 2.

[0570] Here, Mode 2 is as follows.

[0571] -Mode 2: TCI state number (TRP number) < number of repetitions

[0572] (Mode 2: TCI state number (TRP number) < number of repetitions)

[0573] For example, the UE can identify the PDCCH, and identify that the TCI state {#1, #2} is indicated by the TCI code point in the DCI, and identify that the PDSCH is repeatedly transmitted four times in total. Here, according to the method of applying the TCI state, the method of the base station sending the PDSCH four times can be divided into the following types.

[0574] Method 1: A cyclic mapping method (for example, the first timing for TRP1 - TCI state #1, the second timing for TRP2 - TCI state #2, the third timing for TRP1 - TCI state #1, the fourth timing for TRP2 - TCI state #2), wherein the number of times the corresponding TCI state is indicated is the same as the number of times each TRP is repeatedly sent (for example, 2 times).

[0575] Method 2: Sequential mapping method (e.g., first timing - TCI state #1 for TRP1, second timing - TCI state #1 for TRP1, third timing - TCI state #2 for TRP2, fourth timing - TCI state #2 for TRP2), where each TRP is repeatedly transmitted (e.g., 2 times), corresponding to one TCI state.

[0576] Reference Fig.17 , when method 1 (cyclic mapping method) is applied, TRP1 can apply TCI state #1 to the first PDSCH (PDSCH #1) and send it to the UE, and TRP2 can continuously apply TCI state #2 to the second PDSCH (PDSCH #2) and send it to the UE. Continuously, TRP1 can apply TCI state #1 to the third PDSCH (PDSCH #3) and send it to the UE, and TRP2 can apply TCI state #2 to the fourth PDSCH (PDSCH #4) and send it to the UE.

[0577] On the contrary, when Fig.18 When method 2 (sequential mapping method) is applied, TRP1 can apply TCI state #1 to the first PDSCH (PDSCH #1) and the second PDSCH (PDSCH #2) and send them to the UE. Subsequently, TRP2 can apply TCI state #2 to the third PDSCH (PDSCH #3) and the fourth PDSCH (PDSCH #4) and send them to the UE.

[0578] The base station may set higher layer parameters so that the UE can identify method 1 and method 2. For example, the base station may allow identification of method 1 and method 2 by including the tciMapping field in the RepetititionSchemeConfig IE as an RRC information element (IE). Here, the tciMapping field enables the TCI state mapping method for PDSCH transmission timing and is set to cyclic mapping (cyclicMapping) or sequential mapping (sequentialMapping). When the value of the tciMapping field is set to "cyclicMapping", the UE can recognize that method 1, i.e., the cyclic mapping method, is applied, and when the value of the tciMapping field is set to "sequentialMapping", the UE can recognize that method 2, i.e., the sequential mapping method, is applied.

[0579] The base station may use a separate field included in the DCI, as well as the tciMapping field as described above, or use an existing TCI field to identify methods 1 and 2. Alternatively, the base station may utilize a parameter or bit resource that can distinguish between method 1 and method 2 in the RRC. That is, the UE that recognizes the DCI may determine the direction of the reception beam through the following recognition process to determine whether to apply the indicated TCI state.

[0580] Modification 3-1

[0581] If the number of TCI states indicated in each TRP is less than Fig.17 The UE can identify whether method 1 is applied and compare the position of the time domain resources of the PDSCH to which the TCI state is applied with timeDurationForQCL to identify whether the TCI state is applied based on the number of repeatedly transmitted PDSCHs shown.

[0582] For example, if the time when the TCI state is applied to the PDSCH in method 1 is after the time based on the set timeDurationForQCL, the UE can assume that all TCI states indicated in the DCI are cyclically mapped to the PDSCH. That is, if the transmission time (start time) of the PDSCH scheduled to apply the TCI state is the same as or after the symbol with a symbol index of 9, the UE recognizes that the last symbol index of the PDCCH sent from the base station is 2 and the set timeDurationForQCL value is 7, when receiving, TCI state #1 can be applied to the first PDSCH allocated from TRP1, TCI state #2 to the second PDSCH allocated from TRP2, TCI state #1 to the third PDSCH allocated from TRP1, and TCI state #2 to the fourth PDSCH allocated from TRP2.

[0583] As another example, if the transmission time (start time) of the PDSCH scheduled to apply the TCI state is equal to or after the symbol with symbol index 1 in the next time slot, the UE that recognizes that the last symbol index of the PDCCH sent from the base station is 2 and the timeDurationForQCL value is set to 14 can, when receiving, apply TCI state #1 to the first PDSCH allocated from TRP1, apply TCI state #2 to the second PDSCH allocated from TRP2, apply TCI state #1 to the third PDSCH allocated from TRP1, and apply TCI state #2 to the fourth PDSCH allocated from TRP2.

[0584] Modification 3-2

[0585] The embodiment related to the default QCL is described as an example in Modification 3-2.

[0586] If the time when the TCI state is applied to the PDSCH is before the position based on the set timeDurationForQCL, the UE that receives multiple PDSCHs indicating the TCI state from the base station does not completely allocate all TCI state information indicated in the DCI to the PDSCH in sequence.

[0587] As an example, if at least one symbol of a first PDSCH (eg, PDSCH#1) among a plurality of PDSCHs exists in Fig.17 In the position based on timeDurationForQCL shown in 17-00 of , a UE that receives multiple PDSCHs indicating TCI states from a base station can apply the default spatial QCL instead of the TCI state #1 indicated in the first PDSCH. Here, the default spatial QCL refers to the QCL parameters used to receive the PDCCH in the CORESET with the lowest CORESET ID associated with the monitored search space in the latest time slot. The UE can apply TCI state #2 to the second PDSCH (PDSCH#2) allocated from TRP2, apply TCI state #1 to the third PDSCH (PDSCH#3) allocated from TRP1, and apply TCI state #2 to the fourth PDSCH (PDSCH#4) allocated from TRP2 in sequence when receiving. That is, although as Fig.17 As shown in 17-30, the base station instructs the UE to apply TCI state #1 to the first PDSCH. If the starting symbol of the first PDSCH is symbol No. 4 and the symbol length is 5, the UE that recognizes that the last symbol index of the PDCCH is 2 and timeDurationForQCL is 7 can apply the default spatial QCL to the first PDSCH when receiving, and apply TCI state #2 to the second PDSCH starting with symbol index 9 (as allocated from TRP2), apply TCI state #1 to the third PDSCH starting from symbol No. 0 in the next time slot (as allocated from TRP1), and apply TCI state #2 to the fourth PDSCH starting from symbol No. 5 in the next time slot.

[0588] The default spatial QCL of the first PDSCH or the second PDSCH may correspond to at least one of TRP1, TRP2, or the TRP for transmitting the DCI.

[0589] Modification 3-3

[0590] The embodiment related to the default QCL is described as an example in Modification 3-3.

[0591] For example, if at least one symbol of a first PDSCH (e.g., PDSCH#1) among multiple PDSCHs exists in a position based on timeDurationForQCL, a UE that receives multiple PDSCHs indicating TCI states from a base station may apply the default spatial QCL, instead of TCI state #1, to the first PDSCH. Upon reception, the UE may sequentially apply TCI state #2 to the second PDSCH (PDSCH#2) allocated from TRP2, apply the default QCL applied to the first PDSCH instead of TCI state #1 to the third PDSCH (PDSCH#3) allocated from TRP1, and apply TCI state #2 to the fourth PDSCH allocated from TRP2.

[0592] As another example, if at least one symbol of a second PDSCH (e.g., PDSCH#2) among multiple PDSCHs exists in a position based on timeDurationForQCL, a UE that receives multiple PDSCHs indicating TCI states from a base station may apply a default spatial QCL, instead of TCI state #1 and TCI state #2, to the first and second PDSCHs. The UE may sequentially apply the default QCL applied to the first PDSCH, instead of TCI state #1, to the third PDSCH allocated from TRP1, and the default spatial QCL applied to the second PDSCH, instead of TCI state #2, to the fourth PDSCH allocated from TRP2. The default spatial QCL applied to the first PDSCH and the default spatial QCL applied to the second PDSCH may be the same or different. The default spatial QCL of the first PDSCH may correspond to at least one of TRP1, TRP2, or a TRP transmitting DCI.

[0593] Modification 3-4

[0594] The embodiment related to the default QCL is described as an example in Modification 3-3.

[0595] For example, in scheme 3, if the starting positions of the repeated multiple PDSCHs are all before the position based on timeDurationForQCL, then the received Fig.18A UE that indicates multiple PDSCHs with TCI states in time slots #0 and #1 from 18 to 00 can apply the default spatial QCL instead of the TCI state indicated for the first PDSCH and the second PDSCH or the first to fourth PDSCH. Here, one or two default QCLs can be set and run based on the single PDCCH default QCL enhancement. That is, although the base station instructs the UE to apply TCI state #1 to TCI state #2 to the first to fourth PDSCHs in time slot #1, if the starting symbol of the first PDSCH is symbol No. 4 and the symbol length is 1, since the symbol indexes of the starting positions of all repeated multiple PDSCHs (No. 4, 5, 6, and 7) are less than the symbol index (No. 9) based on the position of timeDurationForQCL, the UE that recognizes that the index of the last symbol of the PDCCH is 2 and timeDurationForQCL is 7 can apply the default spatial QCL to the first to fourth PDSCHs. In this case, two default QCLs can be set or determined, and the PDSCH can be received by applying them.

[0596] Modification 4-1

[0597] if Fig.18 If the number of TCI states indicated in each TRP is less than the number of repeatedly transmitted PDSCHs, the UE can identify whether method 2 is applied and compare the position of the time domain resources of the PDSCH to which the TCI state is applied with timeDurationForQCL to identify whether the TCI state is applied.

[0598] For example, if the time when the TCI state is applied to the PDSCH in case 1 is after the position based on the set timeDurationForQCL, the UE can consider that all TCI states indicated in the DCI are mapped to the PDSCH in sequence. That is, if the transmission time (start time) of the PDSCH scheduled to apply the TCI state is the same as or after symbol No. 9, the UE that recognizes that the last symbol index of the PDCCH sent from the base station is 2 and the set timeDurationForQCL value is 7 can apply TCI state #1 to the first PDSCH (PDSCH #1) allocated from TRP1, apply TCI state #1 to the second PDSCH (PDSCH #2) allocated from TRP1, apply TCI state #2 to the third PDSCH (PDSCH #3) allocated from TRP2, and apply TCI state #2 to the fourth PDSCH (PDSCH #4) allocated from TRP2 when receiving.

[0599] As another example, if the transmission time (start time) of the PDSCH scheduled to apply the TCI state in the next time slot is equal to symbol No. 1 or after symbol No. 1, the UE that recognizes that the last symbol index of the PDCCH sent from the base station is 2 and the set timeDurationForQCL value is 14 can, when receiving, apply TCI state #1 to the first PDSCH allocated from TRP1, apply TCI state #1 to the second PDSCH allocated from TRP1, apply TCI state #2 to the third PDSCH allocated from TRP1, and apply TCI state #2 to the fourth PDSCH allocated from TRP2.

[0600] Modification 4-2

[0601] If the time when the TCI state is applied to the PDSCH is before the position based on the set timeDurationForQCL, the UE that receives multiple PDSCHs indicating the TCI state from the base station will not completely and sequentially allocate all TCI state information indicated in the DCI to the PDSCH.

[0602] As an example, if at least one symbol of a first PDSCH (eg, PDSCH#1) among a plurality of PDSCHs is Fig.18 -00 is positioned in a position based on timeDurationForQCL, a UE that receives multiple PDSCHs indicating TCI states from a base station can apply the default spatial QCL instead of TCI state #1 indicated in the first PDSCH. The default spatial QCL refers to the QCL parameters used to receive PDCCH in the CORESET with the lowest CORESET ID associated with the monitored search space in the latest time slot. The UE can apply TCI state #1 to the second PDSCH allocated from TRP1, TCI state #2 to the third PDSCH allocated from TRP2, and TCI state #2 to the fourth PDSCH allocated from TRP2 in sequence when receiving. That is, although as Figure 18-30 indicates that the base station instructs the UE to apply TCI state #1 to the first PDSCH. If the starting symbol of the first PDSCH is symbol No. 4 and the symbol length is 5, the UE that recognizes that the last symbol index of the PDCCH is 2 and timeDurationForQCL is 7 can apply the default spatial QCL to the first PDSCH when receiving, apply TCI state #1 to the second PDSCH in which the symbol index assigned from TRP1 starts from 9, and apply TCI state #2 to the third and fourth PDSCHs starting from symbol No. 0 (as assigned from TRP2) in the next time slot. The default spatial QCL of the first PDSCH can correspond to at least one of TRP1, TRP2, or the TRP for transmitting DCI. The default spatial QCL can be the default spatial QCL mentioned in variant example 3-2.

[0603] Modification 4-3

[0604] As an example, if at least one symbol of the first or second PDSCH (e.g., PDSCH #1 or #2) among the multiple PDSCHs exists in a position based on timeDurationForQCL, a UE that receives multiple PDSCHs indicating TCI states from a base station may apply a default spatial QCL instead of TCI state #1 indicated in the first PDSCH. However, the UE may sequentially apply the default spatial QCL to the second PDSCH allocated from TRP1 and apply TCI state #2 to the third and fourth PDSCHs allocated from TRP2 upon reception.

[0605] As another example, if at least one symbol of a second PDSCH (e.g., PDSCH#2) among a plurality of PDSCHs exists in a position based on timeDurationForQCL, a UE receiving a plurality of PDSCHs indicating a TCI state from a base station may universally apply a default spatial QCL to the first to fourth PDSCHs. The default spatial QCL of the first and third PDSCHs may correspond to at least one of TRP1, TRP2, or a TRP for transmitting DCI.

[0606] Modification 4-4

[0607] For example, if the starting positions of all repeated PDSCHs are less than timeDurationForQCL, a UE that receives a PDSCH indicating a TCI state in time slot 0 / 1 as in 18-00 from a base station, particularly in scheme 3, can apply a default spatial QCL instead of the TCI state indicated for the first PDSCH and the second PDSCH or the first to fourth PDSCHs. Here, one or two default QCLs can be set and run based on a single PDCCH default QCL enhancement. That is, although the base station instructs the UE to apply TCI state #1 and TCI state #2 to the first to fourth PDSCHs in time slot 1, if the starting symbol of the first PDSCH is symbol No. 4 and the symbol length is 1, the UE that recognizes that the last symbol index of the PDCCH is 2 and timeDurationForQCL is 7 can apply the default spatial QCL to the first to fourth PDSCHs, because the symbol index of the starting position of all repeated multiple PDSCHs is less than the symbol index (No. 9) considering the position of timeDurationForQCL. In this case, two default QCLs may be set or determined, and the PDSCH may be received by applying them.

[0608] Meanwhile, the meaning of the default spatial QCL described in Modification 3 / 4 and the above-mentioned meaning can be extended as follows and can be applied to all embodiments.

[0609] 1) The meaning described in the above-mentioned variant 3 / 4, that is, the QCL parameter is used to receive the PDCCH in the CORESET with the lowest CORESET ID associated with the monitored search space in the latest time slot.

[0610] 2) The default spatial QCL for PDSCH set by, for example, MAC-CE (default spatial QCL for PDSCH). In this case, the same default spatial QCL may be set for all TRPs, or a different default spatial QCL may be set for each TRP.

[0611] 3) The default spatial QCL of the PDSCH may indicate a value having the lowest ID in the TCI state of the PDSCH set by the RRC or a value having the lowest ID in the TCI state of the PDSCH activated by the MAC-CE.

[0612] Different default spatial QCLs may be applied depending on the context. For example, in case of cross-carrier scheduling or cross-BWP scheduling, the default spatial QCL as described in 3) may be applied, and in other cases, the default spatial QCL as described in 1) or the default spatial QCL as described in 2) may be applied. In the case where the UE supports a MAC-CE for configuring a default spatial QCL for PDSCH, the default spatial QCL as described in 1) may be applied before activating the corresponding MAC-CE, and the default spatial QCL as described in 2) may be applied thereafter.

[0613] 4) Among the TCI states set as TCI in the DCI field, the TCI state corresponding to the lowest code point may be used as the default QCL. As an example, the lowest code point may refer to the code point itself having the smallest index value among the code points of the TCI field. In this case, the lowest code point may include two or more TCI states. As another example, the lowest code point may represent the minimum value (index) among the code points including at least two or more TCI states among the multiple code points of the TCI field.

[0614] For example, when the number of TCI states indicated by the lowest code point is 2, both the first TCI state and the second TCI state may be determined as the default QCL. That is, if both the determined first and second TCI states are determined as the default QCL, the UE may perform beamforming based on both the first and second TCI states. As another example, when the number of TCI states indicated by the lowest code point is 2, at least one of the first TCI state and the second TCI state may be determined as the default QCL. That is, if only the first TCI state is determined as the default QCL, the UE may perform beamforming based only on the first TCI state, and if only the second TCI state is determined as the default QCL, the UE may perform beamforming based only on the second TCI state. The method for determining one of the two TCI states may follow the settings of the base station and the UE or follow a predetermined operation.

[0615] 5) When all TCI code points contain a TCI state and are mapped, the Rel-15 based base station / UE operates as follows.

[0616] The above-mentioned default QCL operation may be a feature defined in the UE capabilities.

[0617] As an example, in the case of the above-mentioned modification examples 3-2 to 4, where Fig.17The UE with cyclMapping enabled as shown may apply the first TCI state of the lowest code point as the default spatial QCL applied to the first PDSCH sent from TRP1, and apply the second TCI state of the lowest code point as the default spatial QCL applied to the second PDSCH sent from TRP2. Further, the UE may apply the TCI state indicated in the scheduling DCI or the first TCI state of the lowest code point as the default spatial QCL applied to the first PDSCH sent from TRP3, and apply the TCI state indicated in the scheduling DCI or the second TCI state of the lowest code point as the default spatial QCL applied to the second PDSCH sent from TRP4.

[0618] As another example, refer to Fig.18 Under the conditions shown in Variant Examples 4-2 to 4-4, a UE with cyclMapping enabled may apply the first TCI state of the lowest code point as the default spatial QCL applied to the first and second PDSCHs sent from TRP1, and apply the TCI state indicated in the scheduling DCI or the second TCI state of the lowest code point as the default spatial QCL applied to the second PDSCH sent from TRPs 3 and 4.

[0619] Fig.18 18-60 show examples in which Koffset between multiple PDSCHs allocated to the UE by the base station in various embodiments of variant examples 3 and 4 is not zero (for example, when Koffset is set to 4). Here, as a condition for changing Koffset, if the position based on timeDurationForQCL exists in an offset region (including the boundary) between PDSCHs on the time axis, the UE can regard the PDSCH existing before the offset as an area for determining whether to apply the default QCL. As an example, if the transmission time (start time) of the PDSCH scheduled to apply the TCI state is equal to or greater than symbol No. 9, the UE that recognizes that the last symbol index of the PDCCH sent from the base station is 2 and the set timeDurationForQCL value is 7 can apply TCI state #1 to the first PDSCH allocated from TRP1 when receiving, apply TCI state #2 to the second PDSCH allocated from TRP2, apply TCI state #1 to the third PDSCH allocated from TRP1, and apply TCI state #2 to the fourth PDSCH allocated from TRP2.

[0620] As another example, although the base station instructs the UE to apply TCI state #1 to the first PDSCH, if the starting symbol of the first PDSCH is symbol number 4 and the symbol length is 4, and Koffset is 2, the UE that recognizes that the last symbol index of the PDCCH is 2 and timeDurationForQCL is 7 can further recognize that timeDurationForQCL exists in the offset region between the first PDSCH and the first PDSCH or in the region before the second PDSCH, and can apply the default spatial QCL to the first PDSCH and apply the above-mentioned various embodiments (Variants 3 and 4) to the second PDSCH to the fourth PDSCH.

[0621] Fig.19 is a flowchart illustrating a method of operating a UE according to an embodiment of the present disclosure.

[0622] Reference Fig.19 , a method for receiving PDSCH based on NC-JT transmission and default QCL assumption of a UE.

[0623] In operation 19-00, during the RRC establishment process with the base station, the UE may receive at least one configuration information including at least one of a parameter related to base station beamforming (e.g., tci-PresentinDCI or RepTCIMapping) and a parameter or configuration information of a control channel and a data channel (e.g., PDDCH-config and PDSCH-config). According to the setting value of the RepTCIMapping parameter, the UE may recognize, for example, data repeatedly transmitted from the base station, resource-related information, and a beamforming mode.

[0624] In addition, in operation 19-00, the UE may send UE capability information (e.g., timeDurationForQCL) to the base station. The UE may send the UE capability information at the request of the base station or at a predetermined time (e.g., during the RRC establishment process with the base station). Accordingly, when the base station receives the capability information of the UE, the operation of receiving the capability may be omitted. Alternatively, the operation of receiving the capability may be omitted according to the configuration information.

[0625] Thereafter, the UE receives the first PDCCH in a specific CORESET based on the configuration information from the base station.

[0626] In addition, in operation 19-10, the UE may identify at least one of resource allocation information for the PDCCH and multiple PDSCHs, TCI-related information, and antenna port information. Figures 16 to 18The repeatedly transmitted data, resource-related information, and beamforming mode described herein are used to repeatedly transmit multiple PDSCHs (eg, two PDSCHs or four PDSCHs).

[0627] Based on the identified information, the UE may calculate a scheduling time offset between the PDCCH and at least one PDSCH (e.g., between the PDDCH and the Nth PDSCH, where N is an integer of 2, 4 or more), and in operations 19-20, the UE may determine at least one of a receiving beamforming direction or a receiving operation (or a receiving operation method) of the Nth PDSCH (e.g., N is an integer of 2, 4 or more) based on the calculation result. As an example, determining the receiving operation method by the UE may include determining at least one of the following: whether to receive data through at least one of the first PDSCH or the second PDSCH, or a method for receiving data when determining to receive data. As another example, determining the receiving operation method by the UE may include determining whether to receive data through at least one of the Nth PDSCH, or when determining to receive data through the Nth PDSCH, determining the repeatedly transmitted data, resource-related information, and a beamforming mode to receive data.

[0628] In operation 19-30, the UE may receive data via the first PDSCH or the second PDSCH corresponding to the first PDCCH or the second PDCCH based on at least one of the information identified in operation 19-10 and the determination result in operation 19-20.

[0629] The UE may perform decoding on the received data.

[0630] Fig. 20 is a diagram illustrating a method for receiving a PDSCH based on NC-JT transmission and a default QCL assumption of a UE according to an embodiment of the present disclosure.

[0631] Reference Fig. 20 , according to UE characteristics, a UE with maxNumberActiveTCI-PerBWP of 1 can report relevant UE capability related information to the base station. The UE can support one activated TCI state per CC or per BWP, and by default the UE can track one activated TCI state to receive PDCCH and PDSCH. When CSI-RS for RLM purposes (e.g., time slot #0), CSI-RS for beam management purposes (e.g., time slot #1), CSI-RS for beam failure detection purposes, or CSI-RS for tracking purposes is configured, the UE can receive periodic CSI-RS, SPS CSI-RS, and aperiodic CSI-RS and measure the channel.

[0632] like Fig. 20As shown in 20-00 of , if beam switching on the first PDCCH is indicated to the UE, and the scheduled first PDSCH and the first CSI-RS for channel measurement overlap on the same OFDM symbol, a situation may arise where the default QCL-based default PDSCH beam conflicts with the CSI-RS QCL type D assumption set in the RRC. In this case, if the start time of the PDSCH is before the time based on timeDurationForQCL, the UE can receive the PDSCH according to the configured default QCL (or enhanced default QCL) to receive the PDSCH allocated from the PDCCH indicating the beam switching, taking into account the set timeDurationForQCL value (for example, 7, 14, or 28 symbols in the case of SCS 60kHz, or 14 or 28kHz in the case of SCS120kHz).

[0633] The (enhanced) default QCL may operate based on at least one of the following various methods.

[0634] 1) The above meaning, ie, the QCL parameter, is used to receive the PDCCH in the CORESET with the lowest CORESET ID associated with the monitored search space in the latest time slot.

[0635] 2) The default spatial QCL of the PDSCH set by, for example, MAC-CE. In this case, the same default spatial QCL can be set for all TRPs, or a different default spatial QCL can be set for each TRP.

[0636] 3) The default spatial QCL of the PDSCH may indicate a value having the lowest ID in the TCI state of the PDSCH set by the RRC or a value having the lowest ID in the TCI state of the PDSCH activated by the MAC-CE.

[0637] Different default spatial QCLs may be applied depending on the context. For example, in the case of cross-carrier scheduling or cross-BWP scheduling, 3) may be applied, while in other cases, 1) or 2) may be applied. In the case where the UE supports a MAC-CE for configuring a default spatial QCL for PDSCH, 1) may be applied before activating the corresponding MAC-CE, and 2) may be applied thereafter.

[0638] 4) A QCL type D assumption of a CSI-RS symbol overlapped on a time domain resource may be applied as an enhanced default QCL for receiving a scheduled PDSCH and received.

[0639] This embodiment can also be applied to the above combination Figures 16 to 18 Various embodiments are described.

[0640] As an example, if multiple PDSCH resources overlap with CSI-RS in time domain resources through multiple TRPs in a single PDCCH, the QCL type D assumption of CSI-RS can be applied to receive PDSCH.

[0641] As another example, Fig.12 and 13 As shown, if each PDSCH scheduled in multiple (e.g., two) PDCCHs is allocated, the base station can configure the CSI-RS in a specific UE, for example, associated with each CORESET index or TRP index to which the PDSCH is allocated. The method of associating the configuration may include directly indicating the CORESET index or TRP index to the CSI-RS, or indicating the CORESET index or TRP index to the SSB or RS referenced by the CSI-RS in the QCL relationship.

[0642] In this case, if the configured CSI-RS resources overlap with the PDSCH sent from the same TRP, the UE can apply the QCL type D assumption of the CSI-RS to receive the overlapping PDSCH. If the configured CSI-RS resources overlap with the PDSCH sent from different TRPs, the UE can apply the default spatial QCL of the PDSCH resources (for example, following at least one of the enhanced default QCL 1), 2) and 3)) or apply the QCL type D assumption of the CSI-RS.

[0643] In addition, if the configured CSI-RS resources overlap with PDSCH sent from at least one TRP, the UE can generally apply the default spatial QCL (for example, following at least one of enhanced default QCL 1), 2) and 3)) or the QCL type D assumption of CSI-RS to receive all PDSCHs sent from the TRP.

[0644] In the case where multiple PDSCHs are repeatedly allocated to have offsets as shown in 16-60, 17-60 and 18-60, if multiple PDSCH resources and CSI-RS do not overlap in time domain resources but overlap with offset symbol resources, the QCL type D assumption of CSI-RS can be applied to receive PDSCH.

[0645] Fig.21A and 21B is a diagram illustrating a method for receiving aperiodic or periodic CSI-RS and PDSCH based on non-coherent joint transmission (NC-JT) of a UE and a default QCL configuration according to various embodiments of the present disclosure.

[0646] Reference Fig.21A , Fig.21A20-10 and 20-20 assume that aperiodic CSI-RS (AP-CSI-RS) is configured in the CORESET in the activated BWP of the triggered cell, and Fig.21A 20-30 assume that no aperiodic CSI-RS is configured in the CORESET in the activated BWP of the triggered cell.

[0647] Fig.21A 20-10 shows an example in which, in time slot #0 to time slot #3, the first serving cell transmits PDCCH #1, PDCCH #2, PDCCH #3, and PDCCH #5 in the configured CORESET (e.g., CORESET #0); specifically, in time slot #0 to time slot #2, PDSCHs (e.g., PDSCH #1 and PDSCH #2) are transmitted based on a single DCI scheduled in PDCCH #1, PDSCHs (e.g., PDSCH #3 and PDSCH #4) are transmitted based on a single DCI scheduled in PDCCH #2, and PDSCHs (e.g., PDSCH #5 and PDSCH #6) are transmitted based on a single DCI scheduled in PDCCH #3. As an example, a PDSCH scheduled based on a single DCI includes one codeword, and if the codewords are transmitted through multiple layers, some of them may be represented as PDSCH #1, and others may be represented as PDSCH #2. Here, one of the multiple beams or TCI states (e.g., two beams / TCI states) indicated in PDCCH#1 is applied to PDSCH#1, and one of the multiple beams or TCI states (e.g., two beams / TCI states) indicated in PDCCH#1 is applied to PDSCH#2.

[0648] As another example, a PDSCH based on a single DCI schedule includes two codewords, multiple layers transmitting one of the two codewords may be represented as PDSCH #1, and multiple layers transmitting the remaining codeword of the two codewords may be represented as PDSCH #2. Here, one indicated among multiple beams or TCI states (e.g., two beams / TCI states) indicated in PDCCH #1 is applied to PDSCH #1, and one indicated among multiple beams or TCI states indicated in PDCCH #1 is applied to PDSCH #2.

[0649] The base station of the first serving cell transmits a periodic CSI-RS (CSI-RS#0 or CSI-RS#0') and an aperiodic CSI-RS (CSI-RS#1 or #5) for measuring the downlink channel of the UE. In this case, the UE can identify the indication for the aperiodic CSI-RS#1 through PDCCH#1 and the indication for the aperiodic CSI-RS#5 through PDCCH#5.

[0650] Fig.21A The serving cell in time slot #0 to time slot #3 in 20-20 represents the above combined Fig.21A The serving cells described in 20-10 are the first serving cell and the second serving cell. Assume that in the second serving cell, the CORESET (eg, CORESET#1) is configured in different activated BWPs. Fig.21A 20-20 shows an example in which the base station of the second serving cell transmits aperiodic CSI-RS#2 and CSI-RS#6 based on the cross-carrier scheduling indication in PDCCH#2 of CORESET#0 in time slot#1, or aperiodic CSI-RS#4 based on the self-carrier scheduling indication in PDCCH#4 of a different CORESET#1. The UE can recognize the indication for aperiodic CSI-RS#2, CSI-RS#4, and CSI-RS#6 via PDCCH#2, PDCCH#4, and PDCCH#5. NC-JT transmission based on a single TRP can be configured in the carrier and BWP to which CORESET#1 belongs.

[0651] Fig.21A The serving cell in time slot #0 to time slot #3 in 20-30 represents the above combined Fig.21A The serving cells described in 20-10 are the first serving cell and the third serving cell. It is assumed that the third serving cell is not configured with a separate CORESET in another activated BWP (unconfigured CORESET). The base station of the third serving cell sends CSI-RS#3 based on the cross-carrier scheduling indication in PDCCH#2 of CORESET#0 in time slot#1 and sends CSI-RS#7 scheduled in PDCCH#5 in time slot#3. Fig.21A 20-30 may include cases where NC-JT transmission based on a single TRP is configured.

[0652] It should be noted that the various embodiments in time slots #0 to #3 do not necessarily require the base station to perform scheduling at the same time, but are only for describing the various embodiments.

[0653] In the following embodiments of the present disclosure, based on the above embodiments of the present disclosure, the operation of configuring and determining the beam by the UE in various scenarios and contexts is described when the scheduling offset between the last symbol of PDCCH#1 to PDCCH#3 received by the UE and the start symbol of the non-periodic CSI-RS#1 to CSI-RS#7 transmitted in the same serving cell (triggering cell) or a different serving cell (triggered cell) is less than the time required to switch the beam (beamSwitchTiming or beamSwitchTiming+d). For the time required to switch the beam, if the parameter sets of the triggering cell (first serving cell) and the triggered cell (second serving cell or third serving cell) are the same, the parameter value of beamSwitchTiming is applied, and if the parameter sets of the triggering cell (first serving cell) and the triggered cell (second serving cell or third serving cell) are different, the parameter value of beamSwitchTiming+d is applied. Here, d represents the beam switching time delay, and when μPDCCH is 0, 1, or 2, d can be calculated and applied as 8, 8, and 14 symbols.

[0654] Example 1-1

[0655] First, if the resources of the aperiodic CSI-RS and the resources of the PDSCH based on NC-JT sent from the base station in a serving cell (i.e., the first serving cell) are based on the triggering cell and the triggered cell as follows: Fig.21A In the case where the same self-scheduling shown in 20-10 is run in time slot #0, there is at least partial overlap (for example, when part of the resources of the aperiodic CSI-RS of the first service cell and part of the resources of the NC-JT-based PDSCH are the same) or complete overlap (for example, when all the resources of the aperiodic CSI-RS of the first service cell and all the resources of the NC-JT-based PDSCH are the same), the UE can apply different QCL configurations of DL signals (for example, PDSCH or periodic / aperiodic CSI-RS) when receiving the aperiodic CSI-RS.

[0656] Here, like PDSCH#1 and PDSCH#2 of multiple TRPs based on a single DCI, if the different DL signals are PDSCHs for NC-JT, the UE cannot change the beam direction for receiving the non-periodic CSI-RS. Therefore, the UE can determine to follow the beam direction for receiving NC-JT-based PDSCH for CORESET#0. In this case, the UE can configure two beams to receive both PDSCH#1 and PDSCH#2, and can be set to receive one of the two beams (e.g., the beam of PDSCH#1 or the beam of PDSCH#2). The operation of selecting one of the two beams may depend on the implementation of the UE or may follow the decision between the base station and the UE.

[0657] When the beam switching of PDSCH can be indicated in PDCCH#1 that schedules PDSCH#1 and PDSCH#2, the UE receiving the beam switching indication determines the beam direction according to the TCI state indicated by the TCI code point in the DCI in PDCCH#1, as long as the time (timeDurationForQCL) for applying the QCL configuration change of the received PDSCH is sufficient to receive PDSCH#1 and PDSCH#2.

[0658] If the time (timeDurationForQCL) for the UE to apply the QCL configuration is insufficient, for example, when timeDurationForQCL is less than a preset value, any one of the extended default QCL operations (e.g., 1) to 5) of the default spatial QCL) described above in combination with variants 3 and 4 may be followed. For example, if the PDSCH is transmitted from the first serving cell based on a single DCI, the UE may use the TCI state corresponding to the lowest code point in the TCI state configured with TCI in the DCI field of PDCCH#2 as the default QCL configuration (e.g., extended default spatial QCL operation 4).

[0659] In the case where the non-periodic CSI-RS does not overlap with the PDSCH or other RS, if a single DCI-based NC-JT (S-DCI-based NC-JT) is configured in the CSI-RS triggered cell, the QCL configuration for CSI-RS reception can be determined according to one of the extended default QCL operations (e.g., 1) to 5) of the extended default spatial QCL) described above in combination with variants 3 and 4. For example, if the single DCI-based NC-JT PDSCH is set to be receivable in the first serving cell, the UE can select one or two TCI states activated by, for example, MAC-CE to receive the PDSCH in the first serving cell and use the selected one or two TCI states as the default QCL configuration for receiving the CSI-RS (e.g., extended default spatial QCL operation 4)). In this case, when two TCI states are selected, one or more TCI code points can be mapped to the two activated TCI states. In this case, the TCI state corresponding to the lowest code point among the TCI code points mapped to the two TCI states can be used as the default QCL configuration (e.g., extended default spatial QCL operation 4)). Here, the UE can apply the QCL configuration corresponding to the two TCI states corresponding to the lowest code point, or apply the QCL configuration corresponding to one (first / second) TCI state of the two TCI states. The operation of determining one of the two TCI states can be based on the implementation of the UE or can follow the decision between the base station and the UE. The UE can perform additional operations through the beam agreed with the base station when receiving a non-periodic CSI-RS by applying the QCL configuration corresponding to the TCI state corresponding to the lowest code point.

[0660] Example 1-2

[0661] First, as an example, as above combined Fig.21A As described in 20-20, if the resources for the non-periodic CSI-RS#2 sent from the base station of a different serving cell (e.g., the second serving cell), when the triggering cell and the triggered cell operate based on different cross-scheduling in time slot #1, and the resources of the NC-JT-based PDSCH of the triggering cell (e.g., the first serving cell), at least partially overlap (e.g., when part of the resources of the non-periodic CSI-RS#2 and part of the resources of the NC-JT-based PDSCH of the first serving cell are the same) or completely overlap (e.g., when all the resources of the non-periodic CSI-RS#2 and all the resources of the NC-JT-based PDSCH of the first serving cell are the same), the UE can apply different QCL configurations of DL signals (e.g., PDSCH or periodic / non-periodic CSI-RS) when receiving the non-periodic CSI-RS.

[0662] Here, like PDSCH#1 and PDSCH#2 of multiple TRPs based on a single DCI, if the different DL signals are PDSCHs of NC-JT, the UE cannot change the beam direction for receiving non-periodic CSI-RS. Therefore, the UE can determine the beam direction that follows the NC-JT-based PDSCH for receiving CORESET#0. In this case, the UE can configure two beams to receive PDSCH#3 and PDSCH#4, and can be set to select only one of the two beams (for example, the beam of PDSCH#3 or the beam of PDSCH#4). The operation of determining one of the two beams can be based on the implementation of the UE or can follow the decision between the base station and the UE.

[0663] When beam switching of PDSCH can be indicated in PDCCH#2 scheduling PDSCH#3 and PDSCH#4, the time (timeDurationForQCL) for the UE receiving the beam switching indication to apply the QCL configuration change according to the beam switching is sufficient, for example, when timeDurationForQCL is not less than a threshold time, the beam direction is determined based on the TCI state indicated in the TCI code point in the DCI in PDCCH#2 to receive PDSCH#3 and PDSCH#4.

[0664] If the time (timeDurationForQCL) for the UE to apply the QCL configuration is insufficient, for example, when timeDurationForQCL is less than a threshold time, one of the extended default QCL operations (e.g., 1) to 5) of the default spatial QCL) described above in conjunction with variants 3 and 4 may be followed. For example, if the PDSCH is transmitted from the first serving cell based on a single DCI, the UE may use the TCI state corresponding to the lowest code point among the TCI states configured with TCI in the DCI field of PDCCH#2 as the default QCL configuration (e.g., extended default spatial QCL operation 4).

[0665] As another example, if transmission is configured in the second serving cell only for a single TRP and a CORESET is configured, the UE may apply the QCL configuration used in the CORESET associated with the search space of the lowest CORESET ID in the latest timeslot in at least one CORESET in the activated BWP of the second serving cell.

[0666] As another example, if multi-TRP transmission based on a single DCI is set in the second service cell, the UE may select one or two of the TCI states activated by, for example, MAC-CE to receive the PDSCH in the activated BWP of the second service cell and use the selected one or two TCI states as the default QCL configuration (e.g., extended default spatial QCL operation 4)). In this case, when two TCI states are selected, one or more TCI code points may be mapped to the two activated TCI states. In this case, the TCI state corresponding to the lowest code point of the TCI code points mapped to the two TCI states may be used as the default QCL configuration (e.g., extended default spatial QCL operation 4)). Here, the UE may apply the QCL configuration corresponding to the two TCI states corresponding to the lowest code point, or apply the QCL configuration corresponding to one (first / second) TCI state of the two TCI states. The operation of determining one of the two TCI states may be based on the implementation of the UE or may follow a decision between the base station and the UE.

[0667] Example 1-3

[0668] First, as an example, as mentioned above Fig.21A As described in 20-20, if the resources of the aperiodic CSI-RS#3 sent from the base station of the third serving cell, when the triggering cell and the triggered cell operate based on different cross-scheduling in time slot #1, and the resources of the NC-JT-based PDSCH of the triggering cell (for example, the first serving cell) are at least partially overlapped (for example, when part of the resources of the aperiodic CSI-RS#3 are the same as part of the resources of the NC-JT-based PDSCH of the first serving cell) or completely overlapped (for example, when all the resources of the aperiodic CSI-RS#3 are the same as all the resources of the NC-JT-based PDSCH of the first serving cell), the UE can apply different QCL configurations of DL signals (for example, PDSCH or periodic / aperiodic CSI-RS) when receiving the aperiodic CSI-RS#3.

[0669] Example 1-3-a

[0670] First, if the triggering cell (i.e., the serving cell) operates as a single TRP, the UE may apply the QCL configuration used in the CORESET associated with the search space of the lowest CORESET ID in the latest time slot in at least one or more CORESETs in the BWP of the serving cell, instead of the beam direction of the non-periodic CSI-RS when receiving the non-periodic CSI-RS.

[0671] Example 1-3-b

[0672] If the triggered cell operates as multiple TRPs based on a single DCI, the UE can apply the QCL configuration described above in combination with Examples 1-2.

[0673] Examples 1-4

[0674] First, if combined Fig.21A As described in 20-20, if the triggering cell (i.e., the first service cell) and the triggered cell (i.e., the second service cell) operate based on the same self-scheduling in time slot #2, and the resources of the aperiodic CSI-RS#4 sent from the base station of the second service cell at least partially overlap with the resources of the NC-JT-based PDSCH of the first service cell (for example, when part of the resources of the aperiodic CSI-RS#4 are the same as part of the resources of the NC-JT-based PDSCH of the first service cell) or completely overlap (for example, when all the resources of the aperiodic CSI-RS#4 and all the resources of the NC-JT-based PDSCH of the first service cell are the same), the UE can apply different QCL configurations of DL signals (e.g., PDSCH or periodic / aperiodic CSI-RS) when receiving the aperiodic CSI-RS#4.

[0675] Here, like PDSCH#1 and PDSCH#2 of multiple TRPs based on a single DCI, if the different DL signals are PDSCH of NC-JT, the UE cannot change the beam direction for receiving non-periodic CSI-RS#4. Therefore, the UE can determine to follow the beam direction for receiving PDSCH based on NC-JT. In this case, the UE can configure two beams to receive both PDSCH#5 and PDSCH#6, and can be set to receive only one of the two beams (for example, the beam of PDSCH#5 or the beam of PDSCH#6). The operation of determining one of the two beams can be based on the implementation of the UE or can follow the decision between the base station and the UE.

[0676] If beam switching of PDSCH#5 and PDSCH#6 is indicated in PDCCH#3 that schedules PDSCH#5 and PDSCH#6, and the time (timeDurationForQCL) for the UE receiving the beam switching indication to apply the QCL configuration change according to the beam switching is sufficient, for example, when timeDurationForQCL is a threshold time or longer, the beam direction is determined according to the TCI state indicated in the TCI code point in the DCI in PDCCH#3 to receive PDSCH#5 and PDSCH#6.

[0677] If the time (timeDurationForQCL) for the UE to apply the QCL configuration is insufficient, for example, when timeDurationForQCL is less than a threshold time, the beam direction for receiving PDSCH#5 and PDSCH#6 may be determined based on whether it is possible to identify whether the search space of CORESET#1 and PDSCH#5 and PDSCH#6 overlap on the time axis resources, or, if possible, determine whether the search space of CORESET#1 and PDSCH#5 and PDSCH#6 overlap on the time axis resources.

[0678] For example, if it is identified that the search space of CORESET#1 and PDSCH#5 and PDSCH#6 overlap at least partially on the time axis resource, for example, when it is identified that the search space of CORESET#1 and PDSCH#5 and PDSCH#6 overlap in at least one symbol on the time axis resource, the UE can be set to follow the default beam of CORESET#1. Here, if the CORESET is configured so that only a single TRP transmits a default beam in the second serving cell, the UE can apply the QCL configuration used in the CORESET associated with the search space of the lowest CORESET ID in the latest time slot in at least one CORESET in the activated BWP of the second serving cell. Alternatively, if multi-TRP transmission based on a single DCI is set in the second serving cell, the UE can select one or two TCI states activated by, for example, MAC-CE to receive PDSCH in the activated BWP of the second serving cell, and use the selected one or two TCI states as the default QCL configuration (e.g., extended default spatial QCL operation 4)). In this case, when two TCI states are selected, one or more TCI code points may be mapped to two activated TCI states. In this case, the TCI state corresponding to the lowest code point of the TCI code points mapped to the two TCI states may be used as the default QCL configuration (e.g., extended default spatial QCL operation 4)). Here, the UE may apply the QCL configuration corresponding to the two TCI states corresponding to the lowest code point, or apply the QCL configuration corresponding to one (first / second) TCI state of the two TCI states. The operation of determining one of the two TCI states may be based on the implementation of the UE or may follow a decision between the base station and the UE.

[0679] As another example, if the UE recognizes that the search space of CORESET#1 and PDSCH#5 and PDSCH#6 do not at least partially overlap, for example, in at least one or more symbols, the UE may determine the QCL configuration to be applied in consideration of the conflict between the default beam of CORESET#0 of the first serving cell and the default beam of CORESET#1 of the second serving cell. If the carrier aggregation combination configured in the UE is an inter-band CA combination of the CC of the first serving cell and the CC of the second serving cell, the UE may apply the default QCL configuration of CORESET#1 of the second serving cell in which the aperiodic CSI-RS (i.e., aperiodic CSI-RS#4) is indicated. If the carrier aggregation combination configured in the UE is an intra-band CA combination of the CC of the first serving cell and the CC of the second serving cell, the UE may apply the default QCL configuration of CORESET#1 of the second serving cell in which the aperiodic CSI-RS (i.e., aperiodic CSI-RS#4) is indicated, or apply the default QCL configuration of CORESET#0 of the first serving cell. If the carrier aggregation combination configured in the UE is an intra-band CA combination of the CC of the first serving cell and the CC of the second serving cell, which one of the default QCL configuration of CORESET#1 of the second serving cell and the default QCL configuration of CORESET#0 of the first serving cell is applied may be based on the implementation of the UE or may follow a decision between the base station and the UE.

[0680] As another example, the UE may assume, based on the configuration / implementation of the base station, that the QCL type D of the default beam configured in the CORESET of the first service cell and the second service cell is the same, regardless of whether the search space of CORESET#1 and PDSCH#5 and PDSCH#6 at least partially overlap in the timeline resources, e.g., in at least one symbol.

[0681] Examples 1-5

[0682] As above combined Fig.21AAs described in 20-20, if the resources of the aperiodic CSI-RS#6 sent from the base station of a different serving cell (e.g., the second serving cell), when the triggering cell and the triggered cell operate based on different cross scheduling in time slot #3, and the resources of the NC-JT-based PDSCH of the triggered cell (e.g., the second serving cell) are at least partially overlapped (e.g., when part of the resources of the aperiodic CSI-RS#6 and part of the resources of the NC-JT-based PDSCH of the second serving cell are the same) or completely overlapped (e.g., when all the resources of the aperiodic CSI-RS#6 and all the resources of the NC-JT-based PDSCH of the second serving cell are the same), the UE can apply different QCL configurations of DL signals (e.g., PDSCH or periodic / aperiodic CSI-RS) when receiving the aperiodic CSI-RS#6.

[0683] Here, like PDSCH#7 and PDSCH#8 of multiple TRPs based on a single DCI, if the different DL signals are PDSCHs for NC-JT, the UE cannot change the beam direction for receiving non-periodic CSI-RS#6. Therefore, the UE can determine to follow the beam direction for receiving NC-JT-based PDSCH. In this case, the UE can configure two beams to receive both PDSCH#7 and PDSCH#8, and can be set to select and receive only one of the two beams (for example, the beam of PDSCH#7 or the beam of PDSCH#8). The operation of selecting one of the two beams can be based on the implementation of the UE or can follow the decision between the base station and the UE.

[0684] If beam switching of PDSCH (i.e., PDSCH#7 and PDSCH#8) is indicated in PDCCH#5 that schedules PDSCH#7 and PDSCH#8, and the time (timeDurationForQCL) for the UE receiving the beam switching indication to apply the QCL configuration change according to the beam switching is sufficient, for example, when timeDurationForQCL is a threshold time or longer, the beam direction is determined according to the TCI state indicated in the TCI code point in the DCI in PDCCH#5 to receive PDSCH#7 and PDSCH#8.

[0685] If the time (timeDurationForQCL) for the UE to apply the QCL configuration is insufficient, for example, when timeDurationForQCL is less than the threshold time, one of the extended default QCL operations (e.g., 1) to 5) of the default spatial QCL) described above in conjunction with variants 3 and 4 may be followed. For example, if the PDSCH is transmitted from the second serving cell based on a single DCI, the UE may use the TCI state corresponding to the lowest code point in the TCI state configured with TCI in the DCI field of PDCCH #6 as the default QCL configuration (e.g., extended default spatial QCL operation 4).

[0686] Examples 1-6

[0687] As above combined Fig.21A As described in 20-30, if the resources for non-periodic CSI-RS#7 sent from the base station of a different serving cell (e.g., the third serving cell), when the triggering cell and the triggered cell operate based on different cross scheduling in time slot #3, and the resources of the NC-JT-based PDSCH of the triggered cell (e.g., the third serving cell) are at least partially overlapped (e.g., when part of the resources of the non-periodic CSI-RS#7 and part of the resources of the NC-JT-based PDSCH of the third serving cell are the same) or completely overlapped (e.g., when all the resources of the non-periodic CSI-RS#7 and all the resources of the NC-JT-based PDSCH of the second serving cell are the same), the UE can apply different QCL configurations of DL signals (e.g., PDSCH or periodic / non-periodic CSI-RS) when receiving the non-periodic CSI-RS#7.

[0688] Here, like PDSCH#9 and PDSCH#10 of multiple TRPs based on a single DCI, if the different DL signals are PDSCH for NC-JT, the UE cannot change the beam direction for receiving non-periodic CSI-RS#7. Therefore, the UE can determine to follow the beam direction for receiving NC-JT-based PDSCH. In this case, the UE can configure two beams to receive both PDSCH#9 and PDSCH#10, and can be set to receive only one of the two beams (for example, the beam of PDSCH#9 or the beam of PDSCH#10). The operation of selecting one of the two beams can be based on the implementation of the UE or can follow the decision between the base station and the UE.

[0689] If beam switching of PDSCH is indicated in PDCCH#5 scheduling PDSCH#9 and PDSCH#10, and the time (timeDurationForQCL) for applying QCL configuration change according to beam switching is sufficient for the UE receiving the beam switching indication, for example, when timeDurationForQCL is a threshold time or longer, the beam direction is determined according to the TCI state indicated in the TCI code point in the DCI in PDCCH#5 to receive PDSCH#9 and PDSCH#10.

[0690] If the time (timeDurationForQCL) for the UE to apply the QCL configuration is insufficient, for example, when timeDurationForQCL is less than a threshold time, one of the extended default QCL operations (e.g., 1) to 5) of the default spatial QCL) described above in conjunction with variants 3 and 4 may be followed. For example, if the PDSCH is transmitted from the third serving cell based on a single DCI, the UE may use the TCI state corresponding to the lowest code point in the TCI state configured with TCI in the DCI field of PDCCH #5 as the default QCL configuration (e.g., extended default spatial QCL operation 4).

[0691] Reference Fig.21B , 20-50 show that in time slot #0 to time slot #3, the first service cell sends PDCCH #1, PDCCH #2, PDCCH #3, PDCCH #5 and PDCCH #6 in the configured CORESET (e.g., CORESET #0 and CORESET #1), specifically, in time slot #0 to time slot #3, two PDSCHs (e.g., PDSCH #1 and PDSCH #2) are sent based on the multi-DCI scheduled in PDCCH #1 and PDCCH #2, two or more PDSCHs (e.g., PDSCH #3 and PDSCH #4) are sent based on the multi-DCI scheduled in PDCCH #3 and PDCCH #4, and two or more PDSCHs (e.g., PDSCH #5 and PDSCH #6) are sent based on the multi-DCI scheduled in PDCCH #7 and PDCCH #8. The base station of the first serving cell transmits a periodic CSI-RS (e.g., CSI-RS#0 or CSI-RS#0') and an aperiodic CSI-RS (e.g., CSI-RS#1 or CSI-RS#5) for measuring a downlink channel of the UE. In this case, the UE can identify the indication of the aperiodic CSI-RS#1 through PDCCH#2, the indication of the aperiodic CSI-RS#2 and CSI-RS#3 through PDCCH#4, and the indication of the aperiodic CSI-RS#5, CSI-RS#6, and CSI-RS#7 through PDCCH#12.

[0692] Fig.21B The time slots #0 to #3 of 20-60 show the operation of the service cell (eg, the first service cell and the second service cell different from the first service cell), as described above in conjunction with Fig.21B As described in 20-50 of . It is assumed that in the second serving cell, CORESET (e.g., CORESET#2 or CORESET#3) is configured in different activated BWPs. The base station of the second serving cell sends the aperiodic CSI-RS#2 indicated by the cross-scheduling in PDCCH#4 of CORESET#1 in time slot#1, or sends the aperiodic CSI-RS#4 indicated by the cross-scheduling in PDCCH#9 of CORESET#2 in time slot#2, or sends the aperiodic CSI-RS#6 indicated by the cross-scheduling in time slot#3. The UE can identify the indication of the aperiodic CSI-RS#2, CSI-RS#4 and CSI-RS#6 through PDCCH#4, PDCCH#9 and PDCCH#12. Fig.21B 20-60 show the case of configuring NC-JT transmission based on multiple TRPs for CORESET#2 and CORESET#3. Fig.21A The described NC-JT transmission configuration based on a single TRP and combined Fig.21B A combination of configurations described.

[0693] Reference Fig.21B 20-70, time slot #0 to time slot #3 show the operation of the service cell (eg, the first service cell and the third service cell different from the first service cell), as described above in conjunction with Fig.21B As described in 20-50 of . It is assumed that the third serving cell does not configure a separate CORESET in another activated BWP (unconfigured CORESET). The base station of the third serving cell sends the aperiodic CSI-RS#3 indicated by the cross-carrier scheduling in PDCCH#2 based on CORESET#1 in time slot#1, and sends the aperiodic CSI-RS#7 scheduled in PDCCH#12 in time slot#3. Fig.21B 20-70 shows the case of a NC-JT transmission configured with multiple TRPs. Fig.21A The described NC-JT transmission configuration based on a single TRP and combined Fig.21B A combination of configurations described.

[0694] It should be noted that the various embodiments in time slots #0 to #3 do not necessarily require the base station to perform scheduling at the same time, but are only for describing the various embodiments.

[0695] In the following embodiments of the present disclosure, based on the above-mentioned embodiments of the present disclosure, it is described that when the scheduling offset between the last symbol of PDCCH#1 to PDCCH#4, PDCCH#7 and PDCCH#8 received by the UE and the start symbol of aperiodic CSI-RS#1 to CSI-RS#7 transmitted in the same serving cell (triggering cell) or different serving cells (triggered cells) is less than the time required to switch beams (beamSwitchTiming or beamSwitchTiming+d), the operation of configuring and determining the beam by the UE in each scenario and context is described. For the time required to switch beams, if the parameter sets of the triggering cell (first serving cell) and the triggered cell (second serving cell or third serving cell) are the same, the parameter value of beamSwitchTiming is applied, and if the parameter sets of the triggering cell (first serving cell) and the triggered cell (second serving cell or third serving cell) are different, the parameter value of beamSwitchTiming+d is applied. Here, d represents the beam switching time delay, and when μPDCCH is 0, 1, or 2, d can be calculated and applied as 8, 8, and 14 symbols.

[0696] Example 2-1

[0697] First, if the resources of the aperiodic CSI-RS in a serving cell (i.e., the first serving cell) and the resources of the NC-JT-based PDSCH sent from the base station are based on the triggering cell and the triggered cell in time slot #0 as in Fig.21B In the same self-scheduling operation case shown in 20-50, with at least partial overlap (for example, when part of the resources of the non-periodic CSI-RS and part of the resources of the NC-JT-based PDSCH of the first serving cell are the same) or full overlap (for example, when all the resources of the non-periodic CSI-RS and all the resources of the NC-JT-based PDSCH of the first serving cell are the same), the UE can apply different QCL configurations of DL signals (for example, PDSCH or periodic / non-periodic CSI-RS) when receiving the non-periodic CSI-RS.

[0698] Here, like PDSCH#1 and PDSCH#2 of multiple TRPs based on a single DCI, if the different DL signals are PDSCH for NC-JT, the UE cannot change the beam direction for receiving aperiodic CSI-RS. Therefore, the UE can determine the beam direction that follows the NC-JT-based PDSCH for receiving CORESET#1. In this case, the UE can configure a beam for each of PDSCH#1 and PDSCH#2 to receive both PDSCH#1 and PDSCH#2.

[0699] When beam switching of PDSCH can be indicated in PDCCH#1 for scheduling PDSCH#1 and PDCCH#2 for scheduling PDSCH#2 and the time (timeDurationForQCL) for the UE receiving the beam switching indication to apply the QCL configuration change according to the beam switching is sufficient, for example, when timeDurationForQCL is not less than a threshold time, the beam direction is determined based on the TCI state indicated in the TCI code point in the DCI in PDCCH#1 and PDCCH#2 to receive PDSCH#1 and PDSCH#2. In this case, the UE can assume two beams for receiving both PDSCH#1 and PDSCH#2 as the QCL configuration for receiving non-periodic CSI-RS and can assume reception of one of the two beams (e.g., the beam direction of PDSCH#1 and the beam direction of PDSCH#2). The operation of selecting one of the two beams can be based on the implementation of the UE or can follow the decision between the base station and the UE. As an example of selecting one of two beams, if two PDSCHs are associated with different CORESETPoolIndex, either beam can be selected based on the TCI state indicated in the PDSCH associated with the same CORESETPoolIndex as the CORESETPoolIndex for the DCI that triggers the non-periodic CSI-RS. Here, CORESETPoolIndex is a field contained in the ControlResourceSet IE which is an RRC IE, and indicates the index of the CORESET pool for the corresponding CORESET. As an example, the ControlResourceSetIE is used to configure the time / frequency CORESET for searching for downlink control information. In addition, although NC-JT transmission is configured in a multi-TRP based on multi-DCI in the first serving cell, a case where only a single PDSCH is transmitted in time slot #0 can be considered. For example, if the PDSCH scheduled in CORESET#0 set to CORESETPoolIndex 0 overlaps with the aperiodic CSI-RS indicated in CORESET#1 set to CORESETPoolIndex 1 (for example, when the resources of the PDSCH scheduled in CORESET#0 and the resources of the aperiodic CSI-RS indicated in CORESET#1 at least partially overlap or completely overlap), the UE can apply the default beam configured in CORESET#1 set to CORESETPoolIndex 1 in which the aperiodic CSI-RS is triggered.The default beam may be applied under the assumption that it is QCL with the RS of the QCL parameters for the PDCCH of the lowest CORESET index among the CORESETs set to the same CORESETPoolIndex value as that of CORESET#1 for PDCCH#2. As another example, if PDSCH#2 scheduled in CORESET#1 set to CORESETPoolIndex 1 overlaps with the aperiodic CSI-RS#1 indicated in CORESET#1 set to CORESETPoolIndex 1 (e.g., when the resources for PDSCH#2 scheduled in CORESET#1 and the resources of the aperiodic CSI-RS#1 indicated in CORESET#1 at least partially overlap or completely overlap), the UE may apply the QCL parameters for receiving PDSCH#2. That is, if it overlaps with the PDSCH belonging to the same CORESETPoolIndex, the UE can apply the PDSCH beam; if it does not overlap, the default beam of the CORESETPoolIndex that has triggered the CSI-RS is applied.

[0700] If the time (timeDurationForQCL) for the UE to apply the QCL configuration is insufficient, for example when timeDurationForQCL is less than a threshold time and the first serving cell transmits multiple PDSCHs based on multi-DCI, the UE may apply it assuming that it is QCL with the RS of the QCL parameters for the PDCCH of the lowest CORESET index in the CORESET set to the same CORESETPoolIndex value (for example, the CORESET is set to the same CORESETPoolIndex value as CORESET#1 for PDCCH#2). The CORESET set to the CORESETPoolIndex value represents a CORESET monitored in the latest timeslot of at least one or more CORESETs associated with the CORESETPoolIndex in the activated BWP of the first serving cell. Such operation may be indicated by the UE's capabilities, and if the UE does not support the operation, the operation specified in Rel-15 is followed regardless of the CORESETPoolIndex. That is, the UE may determine the DMRS port of the received PDSCH based on the QCL parameters used in the CORESET with the lowest CORESET ID associated with the monitored search space in the latest slot.

[0701] Example 2-2

[0702] If resources of the aperiodic CSI-RS#2 transmitted from the base station of the serving cell (e.g., the second serving cell) at least partially overlap (e.g., when part of the resources of the aperiodic CSI-RS#2 are the same as part of the resources of the NC-JT-based PDSCH of the first serving cell) or completely overlap (e.g., when all the resources of the aperiodic CSI-RS#2 are the same as all the resources of the NC-JT-based PDSCH of the first serving cell), in the case where the triggering cell and the triggered cell operate based on different cross-scheduling in time slot #1, as combined with resources of the NC-JT-based PDSCH of the triggering cell (e.g., the first serving cell), Fig.21B As described in 20-60, the UE may apply different QCL configurations of DL signals (eg, PDSCH or periodic / aperiodic CSI-RS) when receiving aperiodic CSI-RS#2.

[0703] Here, like PDSCH#3 and PDSCH#4 of multi-TRP based on multi-DCI, if the different DL signals are PDSCH for NC-JT, the UE cannot change the beam direction for receiving aperiodic CSI-RS#2. Therefore, the UE can determine to follow the beam direction for receiving NC-JT-based PDSCH of CORESET#1 by default. In this case, the UE can configure two beams to receive both PDSCH#3 and PDSCH#4.

[0704] When beam switching of PDSCH can be indicated in PDCCH#3 for scheduling PDSCH#3 and PDCCH#4 for scheduling PDSCH#4, the time (timeDurationForQCL) for the UE receiving the beam switching indication to apply the QCL configuration change according to the beam switching is sufficient, for example, when timeDurationForQCL is not less than the threshold time, the beam direction is determined according to the TCI state indicated in the TCI code point in the DCI in PDCCH#3 and PDCCH#4 to receive PDSCH#3 and PDSCH#4. In this case, the UE can assume that both beams used to receive PDSCH#3 and PDSCH#4 are used as QCL configurations for receiving non-periodic CSI-RS#2, and can assume the beam direction of receiving only one of the two beams (for example, the beam direction of PDSCH#3 and the beam direction of PDSCH#4). The operation of selecting one of the two beams can be based on the implementation of the UE or can follow the decision between the base station and the UE. As an example of selecting one of two beams, if two PDSCHs are associated with different CORESETPoolIndex, the beam can be determined based on the TCI state indicated in the PDSCH associated with the same CORESETPoolIndex as the DCI used to trigger the non-periodic CSI-RS.

[0705] Although multi-DCI based multi-TRP NC-JT transmission has been configured in the first serving cell, it may be considered to transmit only a single PDSCH in time slot #1. For example, if PDSCH #3 scheduled in CORESET #0 set to CORESETPoolIndex0 overlaps with the aperiodic CSI-RS #2 indicated in CORESET #1 set to CORESETPoolIndex 1 (for example, when the resources of PDSCH #3 scheduled in CORESET #0 and the resources of the aperiodic CSI-RS #2 indicated in CORESET #1 at least partially overlap or completely overlap), the UE may apply the default beam configured in CORESET #1 set to CORESETPoolIndex 1 in which the aperiodic CSI-RS #2 is triggered. The default beam may be applied under the assumption that the RS with the QCL parameters for the PDCCH of the lowest CORESET index in the CORESET set to the same CORESETPoolIndex value as that of CORESET#1 for PDCCH#4 is QCL. As another example, if PDSCH#4 scheduled in CORESET#1 set to CORESETPoolIndex 1 overlaps with the aperiodic CSI-RS#2 indicated in CORESET#1 set to CORESETPoolIndex 1 (e.g., when the resources of PDSCH#4 scheduled in CORESET#1 and the resources of the aperiodic CSI-RS#2 indicated in CORESET#1 overlap at least partially or completely), the UE may apply the QCL parameters for receiving PDSCH#4. That is, if the resources of the PDSCH and the resources of the aperiodic CSI-RS belonging to the same CORESETPoolIndex overlap (for example, when the PDSCH resources and the resources of the aperiodic CSI-RS belonging to the same CORESETPoolIndex are all the same or at least partially the same), the UE can apply the PDSCH beam, and if they do not overlap, the default beam of the CORESETPoolIndex that has triggered the CSI-RS is applied.

[0706] If the time (timeDurationForQCL) for the UE to apply the QCL configuration is insufficient, for example when timeDurationForQCL is less than a threshold time and the first serving cell transmits multiple PDSCHs based on multi-DCI, the UE may apply it under the assumption that it is QCL'd with the RS for the QCL parameters of the PDCCH of the lowest CORESET index in the CORESET set to the same CORESETPoolIndex value (for example, the CORESET set to the same CORESETPoolIndex value as CORESET#1 for PDCCH#4). The CORESET set to the CORESETPoolIndex value represents a CORESET monitored in the latest timeslot of at least one or more CORESETs associated with the CORESETPoolIndex in the activated BWP of the first serving cell.

[0707] As another example, if multiple PDSCHs are transmitted based on multiple DCIs in the second serving cell (e.g., multiple TRP transmissions), the UE may apply under the assumption that it is QCL'd with respect to the RS for the QCL parameters of the PDCCH with the lowest CORESET index in the CORESET set to the same CORESETPoolIndex value as the most recently monitored CORESET in the activated BWP of the second serving cell (e.g., the CORESET set to the same CORESETPoolIndex value as CORESET#1 for PDCCH#4). Such operation may be indicated by the UE's capabilities, and if the UE does not support the operation, the operation specified in Rel-15 is followed regardless of the CORESETPoolIndex. That is, the UE may determine the DMRS port of the received PDSCH based on the QCL parameters used in the CORESET associated with the monitored search space with the lowest CORESET ID in the most recent slot.

[0708] Example 2-3

[0709] If the resources of the aperiodic CSI-RS#3 transmitted from the base station of the serving cell (e.g., the third serving cell) at least partially overlap (e.g., when part of the resources of the aperiodic CSI-RS#3 are the same as part of the resources of the NC-JT-based PDSCH of the first serving cell) or completely overlap (e.g., when all the resources of the aperiodic CSI-RS#3 are the same as all the resources of the NC-JT-based PDSCH of the first serving cell) with the resources of the NC-JT-based PDSCH of the triggering cell (e.g., the first serving cell) when the triggering cell and the triggered cell operate based on different cross-scheduling in time slot #1, as described above in conjunction with Fig.21B As described in 20-70, the UE can apply different QCL configurations of DL signals (e.g., PDSCH or periodic / aperiodic CSI-RS) when receiving aperiodic CSI-RS#3.

[0710] Example 2-3-a

[0711] If the triggering cell operates as a single TRP, the UE may apply the QCL configuration used in the CORESET associated with the search space of the lowest CORESET ID in at least one or more CORESETs in the BWP of the first serving cell in the latest time slot, instead of the beam direction of the aperiodic CSI-RS when receiving the aperiodic CSI-RS.

[0712] Example 2-3-b

[0713] If the triggered cell operates as a multi-TRP based on multi-DCI, the UE may apply the QCL configuration as described above in conjunction with Example 2-2.

[0714] Example 2-4

[0715] If the resources of the aperiodic CSI-RS#4 transmitted from the base station of the serving cell (e.g., the second serving cell) at least partially overlap (e.g., when part of the resources of the aperiodic CSI-RS#4 are the same as part of the resources of the NC-JT-based PDSCH of the first serving cell) or completely overlap (e.g., when all the resources of the aperiodic CSI-RS#4 are the same as all the resources of the NC-JT-based PDSCH of the first serving cell) with the resources of the NC-JT-based PDSCH of the first serving cell, when the triggering cell and the triggered cell are operated based on the same self-scheduling in time slot #2, as described above in conjunction with Fig.21B As described in 20-60, the UE may apply different QCL configurations of DL signals (eg, PDSCH or periodic / aperiodic CSI-RS) when receiving aperiodic CSI-RS#4.

[0716] Here, like PDSCH#1 and PDSCH#2 of multi-TRP based on a single DCI, if the different DL signals are PDSCH for NC-JT, the UE cannot change the beam direction for receiving non-periodic CSI-RS. Therefore, the UE can determine to follow the beam direction for receiving PDSCH based on NC-JT. In this case, the UE can configure two beams to receive both PDSCH#5 and PDSCH#6.

[0717] When beam switching of PDSCH can be indicated in PDCCH#7 for scheduling PDSCH#5 and PDCCH#8 for scheduling PDSCH#6, the time (timeDurationForQCL) for the UE receiving the beam switching indication to apply the QCL configuration change according to the beam switching is sufficient, for example, when timeDurationForQCL is not less than a threshold time, the beam direction is determined based on the TCI state indicated in the TCI code point in the DCI in PDCCH#7 and PDCCH#8 to receive PDSCH#5 and PDSCH#6.

[0718] Although multi-DCI based multi-TRP NC-JT transmission has been configured in the first serving cell, it may be considered to transmit only a single PDSCH in time slot #1. For example, if PDSCH #3 scheduled in CORESET #0 set to CORESETPoolIndex 0 overlaps with the aperiodic CSI-RS #3 indicated in CORESET #1 set to CORESETPoolIndex 1 (for example, when the resources of PDSCH #3 scheduled in CORESET #0 set to CORESETPoolIndex 0 and the resources of the aperiodic CSI-RS #3 indicated in CORESET #1 set to CORESETPoolIndex 1 at least partially overlap), the UE may apply the default beam configured in CORESET #1 set to CORESETPoolIndex 1 in which the aperiodic CSI-RS #3 is triggered. The default beam may be applied under the assumption that the RS with the QCL parameters for the PDCCH of the lowest CORESET index in the CORESET set to the same CORESETPoolIndex value as that of CORESET#1 for PDCCH#4 is QCL. As another example, if PDSCH#4 scheduled in CORESET#1 set to CORESETPoolIndex 1 overlaps with the aperiodic CSI-RS#3 indicated in CORESET#1 set to CORESETPoolIndex 1 (e.g., when the resources of PDSCH#4 scheduled in CORESET#1 set to CORESETPoolIndex 1 and the resources of the aperiodic CSI-RS#3 indicated in CORESET#1 set to CORESETPoolIndex 1 at least partially overlap), the UE may apply the QCL parameters for receiving PDSCH#4. That is, if the PDSCH resources belonging to the same CORESETPoolIndex overlap with the resources of the non-periodic CSI-RS, the UE can apply the PDSCH beam, and if the resources of the PDSCH belonging to the same CORESETPoolIndex do not overlap with the resources of the non-periodic CSI-RS, the default beam of the CORESETPoolIndex of the triggered CSI-RS is applied.

[0719] If the time (timeDurationForQCL) for the UE to apply the QCL configuration is insufficient, for example, when timeDurationForQCL is less than a threshold time, the UE may apply under the assumption that the RS of the QCL parameters for the PDCCH of the lowest CORESET index in the CORESET set to the same CORESETPoolIndex value in CORESET#2, CORESET#3, or CORESET#0 or CORESET#1 (for example, a CORESET set to the same CORESETPoolIndex value as CORESET#2 for PDCCH#9) is QCL. The CORESET set to the CORESETPoolIndex value represents a CORESET monitored in the latest timeslot of at least one or more CORESETs associated with the CORESETPoolIndex in the activated BWP of the first serving cell.

[0720] Example 2-5

[0721] First, as mentioned above, Fig.21B As described in 20-60, if the resources of the aperiodic CSI-RS#6 sent from the base station of a different serving cell (e.g., the second serving cell), when the triggering cell and the triggered cell operate based on different cross-scheduling in time slot #3, and the resources of the NC-JT-based PDSCH of the triggered cell (e.g., the second serving cell) are at least partially overlapped (e.g., when part of the resources of the aperiodic CSI-RS#6 and part of the resources of the NC-JT-based PDSCH of the second serving cell are the same) or completely overlapped (e.g., when all the resources of the aperiodic CSI-RS#6 and all the resources of the NC-JT-based PDSCH of the second serving cell are the same), the UE can apply different QCL configurations of DL signals (e.g., PDSCH or periodic / aperiodic CSI-RS) when receiving the aperiodic CSI-RS.

[0722] Here, like PDSCH#7 and PDSCH#8 of...

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: receiving, from a base station BS, physical downlink control channel PDCCH configuration information including two different values ​​of a control resource set CORESET pool index; receiving, from the BS, information indicating that a predefined quasi co-located QCL relationship can be applied based on a CORESET pool index; receiving a PDCCH triggering an aperiodic channel state information reference signal CSI-RS from the BS; receiving the aperiodic CSI-RS from the BS; as well as Sending information indicating whether the terminal supports applying the predefined QCL relationship based on the CORESET pool index to the BS; If the scheduling offset between the last symbol of the PDCCH and the starting symbol of the aperiodic CSI-RS is less than the duration of QCL application, the QCL parameters applied to the aperiodic CSI-RS are determined according to the CORESET pool index associated with the PDCCH.

2. The method according to claim 1, in, If there is another downlink signal in the same time resource as the non-periodic CSI-RS, the QCL parameters applied to the non-periodic CSI-RS are determined as the QCL parameters of the other downlink signal, wherein the other downlink signal is associated with the same CORESET pool index as the CORESET pool index associated with the PDCCH.

3. The method according to claim 2, in, The another downlink signal corresponds to a physical downlink shared channel PDSCH scheduled by another PDCCH, and the another PDCCH is associated with a CORESET pool index that is the same as the CORESET pool index associated with the PDCCH.

4. The method according to claim 1, in, If there is no other downlink signal in the same time resource as the non-periodic CSI-RS, the QCL parameters applied to the non-periodic CSI-RS are determined to be the QCL parameters associated with the lowest CORESET index in the CORESET, where the CORESET is configured to have a CORESET pool index that is the same as the CORESET pool index associated with the PDCCH.

5. The method according to claim 3, wherein: The PDSCH is scheduled within a time greater than or equal to a threshold time for performing the PDCCH reception and applying the QCL parameter.

6. A method performed by a terminal in a wireless communication system, the method comprising: receiving, from a base station BS, physical downlink control channel PDCCH configuration information including two different values ​​of a control resource set CORESET pool index; receiving, from the BS, information indicating that a predefined quasi co-located QCL relationship can be applied based on a CORESET pool index; receiving the PDCCH from the BS; receiving a physical downlink shared channel PDSCH scheduled by the PDCCH from the BS, and sending information indicating whether the terminal supports applying the predefined QCL relationship based on the CORESET pool index to the BS, Among them, if the offset between the reception of the PDCCH and the reception of the PDSCH is less than the threshold for applying the QCL relationship, the QCL relationship applied to the PDSCH is determined according to the CORESET with the lowest CORESET index among the CORESETs configured with the same value as the CORESET pool index of the PDCCH.

7. The method according to claim 6, wherein: The QCL relation applied to the PDSCH is determined as the QCL relation applied to a reference signal RS for a QCL relation of another PDCCH used for the CORESET.

8. The method according to claim 7, wherein: The CORESETs include a CORESET monitored in a latest time slot in at least one CORESET associated with a CORESET pool index within an activated bandwidth part BWP of a serving cell.

9. The method according to claim 7, wherein: The CORESET with the lowest CORESET index is associated with the monitored search space that is associated with the lowest CORESET index in the CORESET.

10. A method performed by a base station BS in a wireless communication system, the method comprising: Generate physical downlink control channel (PDCCH) configuration information including two different values ​​of a control resource set (CORESET) pool index; generating first information indicating that a predefined quasi co-located QCL relationship can be applied based on a CORESET pool index; Sending the PDCCH configuration information to the terminal; sending the first information to the terminal; Sending a PDCCH that triggers an aperiodic channel state information reference signal CSI-RS to the terminal; Sending the aperiodic CSI-RS to the terminal; as well as receiving second information from the terminal indicating whether the terminal supports applying the predefined QCL relationship based on the CORESET pool index, If the scheduling offset between the last symbol of the PDCCH and the starting symbol of the non-periodic CSI-RS is less than the duration of QCL application, the QCL parameters applied to the non-periodic CSI-RS are determined according to the CORESET pool index associated with the PDCCH.

11. The method according to claim 10, further comprising: Third information indicating whether the terminal supports a predefined QCL relationship having a plurality of QCL relationships is received from the terminal.

12. A terminal in a wireless communication system, the terminal comprising: Transceiver; as well as A processor, wherein the processor is configured to: receiving, via the transceiver, physical downlink control channel (PDCCH) configuration information including two different values ​​of a control resource set (CORESET) pool index from a base station (BS), receiving, via the transceiver, from the BS, information indicating that a predefined quasi co-location QCL relationship can be applied based on a CORESET pool index, receiving, via the transceiver, from the BS a PDCCH triggering an aperiodic channel state information reference signal CSI-RS, receiving the aperiodic CSI-RS from the BS via the transceiver, and sending, via the transceiver, to the BS information indicating whether the terminal supports application of the predefined QCL relationship based on the CORESET pool index, If the scheduling offset between the last symbol of the PDCCH and the starting symbol of the aperiodic CSI-RS is less than the duration of QCL application, the QCL parameters applied to the aperiodic CSI-RS are determined according to the CORESET pool index associated with the PDCCH.

13. A base station BS in a wireless communication system, the BS comprising: Transceiver; as well as A processor, wherein the processor is configured to: generating physical downlink control channel (PDCCH) configuration information including two different values ​​of a control resource set (CORESET) pool index, generating first information indicating that a predefined quasi co-located QCL relationship can be applied based on a CORESET pool index, sending the PDCCH configuration information to a terminal via the transceiver, sending the first information to the terminal via the transceiver, sending, via the transceiver, to the terminal a PDCCH that triggers an aperiodic channel state information reference signal CSI-RS, sending the aperiodic CSI-RS to the terminal via the transceiver, and receiving, via the transceiver, from the terminal second information indicating whether the terminal supports application of the predefined QCL relationship based on the CORESET pool index, If the scheduling offset between the last symbol of the PDCCH and the starting symbol of the non-periodic CSI-RS is less than the duration of QCL application, the QCL parameters applied to the non-periodic CSI-RS are determined according to the CORESET pool index associated with the PDCCH.

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