Method and device for supporting plurality of trp operations based on one improved pdcch by using integrated TCI framework in next generation mobile communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. According to one embodiment, a method performed by a terminal in a wireless communication system may comprise the steps of: receiving, from a base station, a radio resource control (RRC) message including information related to at least one transmission configuration indicator (TCI) state; receiving, from the base station, a media access control (MAC) control element (CE) for activating the at least one TCI state, the MAC CE including first information corresponding to a first TCI state related to at least one code point, second information corresponding to a second TCT state related to the one code point, and TCI state ID information according to the first information and the second information; receiving, from the base station, downlink control information (DCI) including a TCI field indicating the one code point; and confirming, on the basis of the RRC message and the MAC CE, TCI state information related to a code point corresponding to the TCI field.

Description

Method and device for supporting enhanced single PDCCH-based multiple TRP operations using an integrated TCI framework in a next-generation mobile communication system

[0001] The present disclosure relates to the operation of a terminal and a base station in a mobile communication system. More specifically, the present disclosure relates to a method and device for supporting multiple TRP operations based on a single PDCCH using a unified TCI (unified TCI) framework in a wireless communication system.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave) such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low latency time that is reduced to one-tenth.

[0003] In the early stages of 5G mobile communication technology, the goal is to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). These include beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2). Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

[0004] Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology in consideration of the services that 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

[0005] In addition, standardization of wireless interface architecture / protocols is in progress for technologies such as intelligent factories (Industrial Internet of Things, IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) that provides nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step random access (2-step RACH for NR) that simplifies random access procedures. Standardization is also in progress for system architecture / services such as 5G baseline architecture (e.g., Service-based Architecture, Service-based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal.

[0006] Once these 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence) from the design stage and AI-based communication technology that realizes system optimization by internalizing end-to-end AI support functions, and ultra-high-performance communication and computing resources to provide services with complexity that exceeds the limits of terminal computing capabilities. It can serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing them.

[0008] Currently, only beam (TCI) state activation / deactivation for a specific BWP (bandwidth part) within a single serving cell is possible. However, as technology advances, the need for methods and devices for transmitting and receiving data through multiple TRPs (Transmission Reception Points) for a specific BWP within or between serving cells is emerging to support multiple TRP operations based on a single PDCCH (Downlink Control Information; DCI).

[0009] The present disclosure proposes a method for transmitting and receiving data through multiple transmission reception points (TRPs) based on unified beam information (unified TCI).

[0010] More specifically, in relation to the operation of setting and activating the integrated beam information (unified TCI state: Unified Transmission Configuration Indication state) used by a terminal for PDCCH / PDSCH / PUCCH / PUSCH in a next-generation mobile communication system using beams, currently only beam (TCI state) activation / deactivation for a specific BWP (bandWidth Part) within a single serving cell is possible. In the present disclosure, in order to support multiple TRP operations based on a single PDCCH (DCI; Downlink Control Information), a method and device for supporting a transmission / reception technique through multiple TRPs (Transmission Reception Points) for a specific BWP within a serving cell or between serving cells are proposed.

[0011] The technical problems to be achieved in the embodiments of the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present disclosure belongs from the description below.

[0012] To solve the above problems, the present disclosure proposes a method performed by a terminal in a wireless communication system. More specifically, the method comprises the steps of: receiving, from a base station, a radio resource control (RRC) message including information related to at least one transmission configuration indicator (TCI) state; receiving, from the base station, media access control (MAC) control information (control element (CE)) for activating at least one TCI state, the MAC CE including first information corresponding to a first TCI state associated with at least one code point, second information corresponding to a second TCI state associated with the one code point, and TCI state identifier (ID) information according to the first information and the second information; receiving, from the base station, downlink control information (DCI) including a TCI field indicating the one code point; and identifying TCI state information related to a code point corresponding to the TCI field based on the RRC message and the MAC CE.

[0013] To solve the above problems, the present disclosure proposes a method performed by a base station in a wireless communication system. More specifically, the method comprises the steps of: transmitting, to a terminal, a radio resource control (RRC) message including information related to at least one transmission configuration indicator (TCI) state; transmitting, to the terminal, media access control (MAC) control information (CE) for activating at least one TCI state, the MAC CE including first information corresponding to a first TCI state associated with at least one code point, second information corresponding to a second TCI state associated with the one code point, and TCI state identifier (ID) information according to the first information and the second information; transmitting, to the terminal, downlink control information (DCI) including a TCI field indicating the one code point, wherein TCI state information related to a code point corresponding to a TCI field included in the DCI is characterized in that it is related to the RRC message and the MAC CE.

[0014] In order to solve the above problems, the present disclosure proposes a terminal in a wireless communication system. More specifically, the terminal includes a transceiver for transmitting and receiving signals; and a control unit, wherein the control unit receives, from a base station, a radio resource control (RRC) message including information related to at least one transmission configuration indicator (TCI) state, and receives, from the base station, a media access control (MAC) control element (CE) for activating at least one TCI state, wherein the MAC CE includes first information corresponding to a first TCI state related to at least one code point, second information corresponding to a second TCI state related to the one code point, and TCI state identifier (ID) information according to the first information and the second information; It is characterized in that downlink control information (DCI) including a TCI field indicating the one code point is received from the base station, and TCI state information related to the code point corresponding to the TCI field is confirmed based on the RRC message and the MAC CE.

[0015] In order to solve the above problems, the present disclosure proposes a base station in a wireless communication system. More specifically, the base station includes a transceiver for transmitting and receiving signals; and a control unit, wherein the control unit transmits, to a terminal, a radio resource control (RRC) message including information related to at least one transmission configuration indicator (TCI) state, and transmits, to the terminal, media access control (MAC) control information (control element (CE)) for activating at least one TCI state, wherein the MAC CE includes first information corresponding to a first TCI state related to at least one code point, second information corresponding to a second TCI state related to the one code point, and TCI state identifier (ID) information according to the first information and the second information; The terminal transmits downlink control information (DCI) including a TCI field indicating the one code point, and TCI state information related to a code point corresponding to the TCI field included in the DCI is characterized in that it is related to the RRC message and the MAC CE.

[0016] According to one embodiment of the present disclosure, a signal can be efficiently transmitted and received in a wireless communication system.

[0017] More specifically, according to one embodiment of the present disclosure, an improved transmission and reception technique via multiple transmission reception points (TRPs) is proposed using a unified transmission configuration indication (TCI) framework. For example, transmission and reception support via a single downlink control information (DCI) can be implemented via multiple TRPs for a specific bandwidth part (BWP) between serving cells.

[0018] The effects that can be obtained from the present disclosure are not limited to the effects mentioned in the various embodiments, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0019] FIG. 1a is a diagram illustrating the structure of a long term evolution (LTE) system according to an embodiment of the present disclosure.

[0020] FIG. 1b is a diagram illustrating a wireless protocol structure in an LTE (long term evolution) system according to an embodiment of the present disclosure.

[0021] FIG. 1c is a diagram illustrating the structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

[0022] FIG. 1d is a diagram illustrating a wireless protocol structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

[0023] FIG. 1e is a diagram illustrating the structure of a next-generation mobile communication system according to another embodiment of the present disclosure.

[0024] FIG. 1f is a diagram illustrating a method for applying a unified transmission configuration indication (TCI) state according to an embodiment of the present disclosure.

[0025] FIG. 1g is a diagram illustrating a method in which a unified TCI state according to one embodiment of the present disclosure is applied to multiple transmission reception points (TRPs).

[0026] FIG. 1h is a diagram illustrating a method for transmitting and receiving data using a unified transmission configuration indication (TCI) framework according to an embodiment of the present disclosure. This diagram illustrates the entire procedure using an enhanced technique.

[0027] FIGS. 1a to 1if are diagrams illustrating the structure of a medium access control (MAC) CE (control element) according to one embodiment of the present disclosure.

[0028] FIG. 1J is a diagram illustrating the operation of a terminal according to an embodiment of the present disclosure.

[0029] FIG. 1k is a diagram illustrating the operation of a base station according to one embodiment of the present disclosure.

[0030] FIG. 1l is a block diagram illustrating the internal structure of a terminal according to an embodiment of the present disclosure.

[0031] FIG. 1m is a block diagram showing the configuration of a new radio (NR) base station according to one embodiment of the present disclosure.

[0032] The operating principles of the present invention will be described in detail below with reference to the attached drawings. In the following description of the present invention, detailed descriptions of known functions or components will be omitted if they are deemed to unnecessarily obscure the gist of the invention. Furthermore, the terms described below are defined based on their functions in the present invention and may vary depending on the intentions or practices of the user or operator. Therefore, their definitions should be based on the overall content of this specification.

[0033] The terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, and terms referring to various identification information are provided for convenience of explanation. Therefore, the present invention is not limited to the terms described below, and other terms referring to objects with equivalent technical meanings may be used.

[0034] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0035] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to ensure that the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0036] At this time, it will be understood that each block of the processing flowchart drawings and combinations of the flowchart drawings can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flowchart block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flowchart block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0037] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0038] Here, the term '~ unit' used in various embodiments of the present disclosure means a software or hardware component such as an FPGA or ASIC, and the '~ unit' can perform certain roles. However, the '~ unit' is not limited to software or hardware. The '~ unit' may be configured to be on an addressable storage medium and may be configured to play one or more processors. Accordingly, as an example, the '~ unit' may include components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. Additionally, components and '~parts' may be implemented to regenerate one or more CPUs within a device or secure multimedia card.

[0039] Hereinafter, the base station is an entity that performs resource allocation of a terminal, and may be at least one of an eNode B (eNB), a Node B, a BS (base station), a RAN (radio access network), an AN (access network), a RAN node, a NR NB, a gNB, a radio access unit, a base station controller, or a node on a network.

[0040] A terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing communication functions. In various embodiments of the present disclosure, a case where the terminal is a UE will be described as an example. In addition, although various embodiments of the present disclosure are described below using a system based on LTE, LTE-A, or NR as an example, various embodiments of the present disclosure may be applied to other communication systems with similar technical backgrounds or channel types. In addition, various embodiments of the present disclosure may be applied to other communication systems with some modifications within a range that does not significantly deviate from the scope thereof, as determined by a person having skilled technical knowledge.

[0041] The terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, terms referring to various identification information, etc. are provided as examples for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects with equivalent technical meanings may be used.

[0042] For convenience of explanation, the present invention uses terms and names defined in the 3GPP LTE (3rd Generation Partnership Project Long Term Evolution) standard. However, the present invention is not limited to these terms and names and can be equally applied to systems conforming to other standards.

[0043] FIG. 1a is a diagram illustrating the structure of a long term evolution (LTE) system according to one embodiment of the present disclosure.

[0044] Referring to Fig. 1a, as illustrated, the wireless access network of the LTE system is composed of next-generation base stations (Evolved Node Bs, hereinafter eNBs, Node Bs or base stations) (1a-05, 1a-10, 1a-15, 1a-20), a Mobility Management Entity (MME, 1a-25) and a Serving-Gateway (S-GW, 1a-30). A user equipment (UE or terminal) (1a-35) connects to an external network through the eNBs (1a-05 to 1a-20) and the S-GW (1a-30).

[0045] In Fig. 1a, eNBs (1a-05 to 1a-20) correspond to the existing Node B of the UMTS system. The eNB is connected to the UE (1a-35) via a wireless channel and performs a more complex role than the existing Node B. In the LTE system, all user traffic, including real-time services such as VoIP (Voice over IP) via the Internet Protocol, is serviced through a shared channel. Therefore, a device that collects status information such as the buffer status of UEs, available transmission power status, and channel status and performs scheduling is required, and the eNBs (1a-05 to 1a-20) are in charge of this. One eNB typically controls multiple cells. For example, in order to implement a transmission rate of 100 Mbps, the LTE system uses, for example, orthogonal frequency division multiplexing (OFDM) as a wireless access technology in a 20 MHz bandwidth. In addition, it applies Adaptive Modulation & Coding (AMC) method that determines modulation scheme and channel coding rate according to the channel condition of the terminal. S-GW (1a-30) is a device that provides data bearers and creates or removes data bearers according to the control of MME (1a-25). MME is a device that is responsible for mobility management function for terminals as well as various control functions and is connected to multiple base stations.

[0046] FIG. 1b is a diagram illustrating a wireless protocol structure in a long term evolution (LTE) system according to an embodiment of the present disclosure.

[0047] Referring to Fig. 1b, the wireless protocol of the LTE system consists of PDCP (Packet Data Convergence Protocol 1b-05, 1b-40), RLC (Radio Link Control 1b-10, 1b-35), and MAC (Medium Access Control 1b-15, 1b-30) in the terminal and eNB, respectively.

[0048] PDCP (1b-05, 1b-40) is responsible for operations such as IP header compression / decompression. The main functions of PDCP are summarized as follows.

[0049] - Header compression and decompression (ROHC only)

[0050] - User data transfer function

[0051] - In-sequence delivery of upper layer PDUs at PDCP re-establishment procedure for RLC AM

[0052] - Order reordering function (For split bearers in DC (only support for RLC AM): PDCP PDU routing for transmission and PDCP PDU reordering for reception)

[0053] - Duplicate detection function (Duplicate detection of lower layer SDUs at PDCP re-establishment procedure for RLC AM)

[0054] - Retransmission function (Retransmission of PDCP SDUs at handover and, for split bearers in DC, of ​​PDCP PDUs at PDCP data-recovery procedure, for RLC AM)

[0055] - Encryption and decryption functions (Ciphering and deciphering)

[0056] - Timer-based SDU discard in uplink.

[0057] Radio Link Control (RLC) (1b-10, 1b-35) reconfigures PDCP PDUs (Packet Data Units) to an appropriate size and performs ARQ operations, etc. The main functions of RLC are summarized as follows.

[0058] - Data transfer function (Transfer of upper layer PDUs)

[0059] - ARQ function (Error Correction through ARQ (only for AM data transfer))

[0060] - Concatenation, segmentation and reassembly of RLC SDUs (only for UM and AM data transfer)

[0061] - Re-segmentation of RLC data PDUs (only for AM data transfer)

[0062] - Reordering of RLC data PDUs (only for UM and AM data transfer)

[0063] - Duplicate detection (only for UM and AM data transfer)

[0064] - Error detection function (Protocol error detection (only for AM data transfer))

[0065] - RLC SDU discard function (RLC SDU discard (only for UM and AM data transfer))

[0066] - RLC re-establishment function

[0067] MAC (1b-15, 1b-30) connects to multiple RLC layer devices configured in a single terminal, and multiplexes RLC PDUs into MAC PDUs and demultiplexes RLC PDUs from MAC PDUs. The main functions of MAC are summarized as follows.

[0068] - Mapping function (Mapping between logical channels and transport channels)

[0069] - Multiplexing and demultiplexing function (Multiplexing / demultiplexing of MAC SDUs belonging to one or different logical channels into / from transport blocks (TB) delivered to / from the physical layer on transport channels)

[0070] - Scheduling information reporting function

[0071] - HARQ function (Error correction through HARQ)

[0072] - Priority handling between logical channels of one UE

[0073] - Priority handling between UEs by means of dynamic scheduling

[0074] - MBMS service identification function (MBMS (multimedia broadcast and multicast service) service identification)

[0075] - Transport format selection function

[0076] - Padding function

[0077] The physical layer (1b-20, 1b-25) performs the operation of channel coding and modulating upper layer data, converting it into OFDM symbols and transmitting it through a wireless channel, or demodulating and channel decoding OFDM symbols received through a wireless channel and transmitting them to the upper layer. In addition, the physical layer also uses HARQ (Hybrid ARQ) for additional error correction, and the receiver transmits whether or not the packet transmitted by the transmitter was received as 1 bit. This is called HARQ ACK / NACK information. Downlink HARQ ACK / NACK information for uplink transmission is transmitted through the PHICH (Physical Hybrid-ARQ Indicator Channel) physical channel, and uplink HARQ ACK / NACK information for downlink transmission can be transmitted through the PUCCH (Physical Uplink Control Channel) or PUSCH (Physical Uplink Shared Channel) physical channel.

[0078] Meanwhile, the above PHY layer can be composed of one or more frequencies / carriers, and the technology that sets and uses multiple frequencies simultaneously is called carrier aggregation (CA). CA technology can dramatically increase the transmission capacity by the number of secondary carriers by additionally using the primary carrier, rather than using only one carrier for communication between a terminal (or User Equipment, UE) and a base station (E-UTRAN NodeB, eNB).

[0079] Meanwhile, in LTE, the cell within the base station that uses the primary carrier is called PCell (Primary Cell), and the secondary carrier is called SCell (Secondary Cell).

[0080] Although not shown in this drawing, an RRC (Radio Resource Control, hereinafter referred to as RRC) layer exists above the PDCP layer of each terminal and base station, and the RRC layer can exchange connection and measurement-related setting control messages for radio resource control.

[0081] FIG. 1c is a diagram illustrating the structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

[0082] Referring to FIG. 1c, as illustrated, the wireless access network of the next-generation mobile communication system is composed of a next-generation base station (New Radio Node B, hereinafter referred to as NR NB, 1c-10) and a NR CN (New Radio Core Network, or NG CN: Next Generation Core Network, 1c-05). A user terminal (New Radio User Equipment, hereinafter referred to as NR UE or terminal, 1c-15) can access an external network through the NR NB (1c-10) and the NR CN (1c-05).

[0083] In Fig. 1c, the NR NB (1c-10) corresponds to the eNB (Evolved Node B) of the existing LTE system. The NR NB is connected to the NR UE (1c-15) via a wireless channel and can provide a service superior to that of the existing Node B. In the next-generation mobile communication system, all user traffic is serviced through a shared channel, so a device that collects status information such as the buffer status of UEs, available transmission power status, and channel status and performs scheduling is required, and the NR NB (1c-10) is responsible for this.

[0084] A single NR NB can typically control multiple cells. To achieve ultra-high-speed data transmission compared to existing LTE, it can have a bandwidth exceeding the existing maximum, and beamforming technology can be additionally incorporated with orthogonal frequency division multiplexing (OFDM) as a wireless access technology. In addition, adaptive modulation and coding (AMC) is applied, which determines the modulation scheme and channel coding rate according to the channel conditions of the terminal.

[0085] The NR CN (1c-05) can perform functions such as mobility support, bearer setup, and QoS configuration. The NR CN is a device responsible for various control functions as well as mobility management for terminals and can be connected to multiple base stations. Furthermore, the next-generation mobile communication system can also be interoperable with the existing LTE system, and the NR CN is connected to the MME (1c-25) via a network interface. The MME is connected to the existing base station, the eNB (1c-30).

[0086] FIG. 1d is a diagram illustrating a wireless protocol structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

[0087] Referring to FIG. 1d, the wireless protocol of the next-generation mobile communication system is composed of NR SDAP (NR service Data Adaption Protocol, 1d-01, 1d-45), NR PDCP (NR Packet Data Convergence Protocol, 1d-05, 1d-40), NR RLC (NR Radio Link Control, 1d-10, 1d-35), and NR MAC (Medium Access Control, 1d-15, 1d-30) in the terminal and NR base station, respectively.

[0088] Key features of NR SDAP (1d-01, 1d-45) may include some of the following:

[0089] - Transfer of user plane data

[0090] - Mapping function between QoS flow and data bearer for both DL and UL

[0091] - Marking function of QoS flow ID for both uplink and downlink (marking QoS flow ID in both DL and UL packets)

[0092] - Ability to map relective QoS flow to data bearer for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

[0093] For the above SDAP layer device, the terminal can be configured by RRC message for each PDCP layer device, each bearer, or each logical channel, whether to use the header of the SDAP layer device or whether to use the function of the SDAP layer device, and when the SDAP header is configured, the terminal can be instructed to update or reset the mapping information for the QoS flow and data bearer of the uplink and downlink with the NAS QoS reflection configuration 1-bit indicator (NAS reflective QoS) and the AS QoS reflection configuration 1-bit indicator (AS reflective QoS) of the SDAP header. The SDAP header can include QoS flow ID information indicating QoS. The QoS information can be used as data processing priority, scheduling information, etc. to support a smooth service.

[0094] The main functions of NR PDCP (1d-05, 1d-40) may include some of the following functions:

[0095] - Header compression and decompression (ROHC only)

[0096] - User data transfer function

[0097] - In-sequence delivery of upper layer PDUs

[0098] - Out-of-sequence delivery of upper layer PDUs

[0099] - Reordering function (PDCP PDU reordering for reception)

[0100] - Duplicate detection of lower layer SDUs

[0101] - Retransmission function (Retransmission of PDCP SDUs)

[0102] - Encryption and decryption functions (Ciphering and deciphering)

[0103] - Timer-based SDU discard in uplink.

[0104] The reordering function of the NR PDCP device above refers to a function of reordering PDCP PDUs received from a lower layer in order based on the PDCP SN (sequence number), and may include a function of transmitting data to an upper layer in the reordered order, or may include a function of transmitting data directly without considering the order, may include a function of recording lost PDCP PDUs by reordering the order, may include a function of reporting the status of lost PDCP PDUs to the transmitting side, and may include a function of requesting retransmission of lost PDCP PDUs.

[0105] The main features of NR RLC(1d-10, 1d-35) may include some of the following:

[0106] - Data transfer function (Transfer of upper layer PDUs)

[0107] - In-sequence delivery of upper layer PDUs

[0108] - Out-of-sequence delivery of upper layer PDUs

[0109] - ARQ function (Error Correction through ARQ)

[0110] - Concatenation, segmentation and reassembly of RLC SDUs

[0111] - Re-segmentation of RLC data PDUs

[0112] - Reordering of RLC data PDUs

[0113] - Duplicate detection function

[0114] - Error detection function (Protocol error detection)

[0115] - RLC SDU discard function

[0116] - RLC re-establishment function

[0117] The in-sequence delivery function of the NR RLC device above refers to the function of sequentially transmitting RLC SDUs received from a lower layer to an upper layer, and may include a function of reassembling and transmitting RLC SDUs when an RLC SDU is originally received divided into multiple RLC SDUs, may include a function of reordering received RLC PDUs based on RLC SN (sequence number) or PDCP SN (sequence number), may include a function of recording lost RLC PDUs by reordering the sequence, may include a function of reporting the status of lost RLC PDUs to the transmitting side, may include a function of requesting retransmission of lost RLC PDUs, may include a function of sequentially transmitting only RLC SDUs up to the lost RLC SDU to an upper layer when there is a lost RLC SDU, or may include a function of sequentially transmitting all RLC SDUs received before the timer starts when a predetermined timer expires even when there is a lost RLC SDU. Or, even if there are lost RLC SDUs, if a predetermined timer has expired, it may include a function to sequentially deliver all RLC SDUs received up to the upper layer. In addition, the RLC PDUs may be processed in the order they are received (in the order of arrival, regardless of the order of the sequence number) and delivered to the PDCP device out of sequence (out-of-sequence delivery). In the case of segments, the segments stored in the buffer or to be received later may be received, reconstructed into a single complete RLC PDU, processed, and then delivered to the PDCP device.The above NR RLC layer may not include a concatenation function, and the function may be performed in the NR MAC layer or replaced with a multiplexing function of the NR MAC layer.

[0118] The out-of-sequence delivery function of the NR RLC device above refers to the function of directly delivering RLC SDUs received from a lower layer to an upper layer regardless of the order, and may include a function of reassembling and delivering RLC SDUs when an original RLC SDU is received divided into multiple RLC SDUs, and may include a function of storing the RLC SN or PDCP SN of received RLC PDUs and arranging the order to record lost RLC PDUs.

[0119] NR MAC (1d-15, 1d-30) can be connected to multiple NR RLC layer devices configured in one terminal, and the main functions of NR MAC can include some of the following functions.

[0120] - Mapping function (Mapping between logical channels and transport channels)

[0121] - Multiplexing and demultiplexing functions (Multiplexing / demultiplexing of MAC SDUs)

[0122] - Scheduling information reporting function

[0123] - HARQ function (Error correction through HARQ)

[0124] - Priority handling between logical channels of one UE

[0125] - Priority handling between UEs by means of dynamic scheduling

[0126] - MBMS service identification function

[0127] - Transport format selection function

[0128] - Padding function

[0129] The NR PHY layer (1d-20, 1d-25) can perform operations such as channel coding and modulating upper layer data, converting it into OFDM symbols and transmitting it through a wireless channel, or demodulating and channel decoding OFDM symbols received through a wireless channel and transmitting them to a higher layer.

[0130] FIG. 1e is a diagram illustrating the structure of a next-generation mobile communication system according to another embodiment of the present disclosure.

[0131] Referring to FIG. 1e, a cell served by a beam-based NR gNB (1e-05) may be composed of multiple TRPs (Transmission Reception Points, 1e-10, 1e-15, 1e-20, 1e-25, 1e-30, 1e-35, 1e-40).

[0132] The above TRP (1e-10 to 1e-40) represents a block that separates some functions of transmitting and receiving physical signals from an existing NR base station (eNB), and is composed of multiple antennas.

[0133] The above NR gNB (1e-05) can be expressed as a CU (Central Unit) and the TRP can be expressed as a DU (Distributed Unit). The functions of the NR gNB (1e-05) and the TRP can be configured by separating each layer in the PDCP / RLC / MAC / PHY layers such as 1e-45. That is, the TRP can perform the function of the corresponding layer with only the PHY layer (1e-15, 1e-25), the TRP can perform the functions of the corresponding layers with only the PHY layer and the MAC layer (1e-10, 1e-35, 1e-40), and the TRP can perform the functions of the corresponding layers with only the PHY layer, the MAC layer, and the RLC layer (1e-20, 1e-30).

[0134] In particular, TRP (1e-10~1e-40) can use beamforming technology to transmit and receive data by creating narrow beams in multiple directions using multiple transmitting and receiving antennas.

[0135] The user terminal (1e-50) can access the NR gNB (1e-05) and the external network through TRP (1e-10 to 1e-40).

[0136] The above NR gNB (1e-05) can support connections between the terminals and the core network (CN), particularly AMF / SMF (1e-50), by collecting and scheduling status information such as the buffer status, available transmission power status, and channel status of the terminals to provide services to users.

[0137] In this disclosure, we propose a method for improving existing operations with respect to the unified transmission configuration indicator (TCI) state structure used to indicate beams to be used when transmitting and receiving data resources across all channels utilized by a terminal in a next-generation mobile communication system. Unlike existing TCI frameworks, the unified TCI framework supports TCI states that can be commonly applied to both uplink and downlink, although the signaling structure differs depending on the mode.

[0138] - Separate UL / DL TCI state mode: Manages by setting separate TCI states for uplink and downlink.

[0139] - Joint TCI DL / UL state mode: Manages by setting the TCI state commonly applied to uplink and downlink.

[0140] In addition, unlike the existing TCI state structure, the unified TCI state can be commonly applied to PDCCH (physical downlink control channel) / PDSCH (physical downlink shared channel) / PUCCH (physical uplink control channel) / PUSCH (physical uplink shared channel). That is, when a beam is indicated through the unified TCI state, the beam can be applied to all channel transmissions in the uplink and downlink. For reference, previously, there was a separate beam management procedure that indicated the spatial relation in the uplink and the TCI state in the downlink.

[0141] The existing unified TCI framework only supports beam management operations, such as inter-cell beam management (ICBM), when only a single TRP exists within a serving cell. However, the present disclosure improves this by supporting transmission and reception techniques supported by multiple TRPs within a single serving cell using the unified TCI framework. In particular, the present disclosure proposes a method of supporting enhanced transmission and reception techniques for multiple TRPs using the aforementioned unified TCI framework by introducing a new MAC CE.

[0142] FIG. 1f is a diagram illustrating a method for applying a unified TCI state according to an embodiment of the present disclosure.

[0143] Referring to FIG. 1f, the procedure for applying a unified TCI state in the NR (new radio) system referred to in the present disclosure and the unified TCI state MAC CE are described. FIG. 1f provides a specific example to explain how the unified TCI state functionally operates.

[0144] A terminal in an RRC (radio resource control) connection state transmits and receives data with a base station (a serving cell, e.g., PCell). The terminal may perform Layer 1 channel measurements according to the base station's settings to switch to an optimal beam and report the results to the base station. The base station can then verify the Layer 1 channel measurements reported by the terminal, determine which beam is currently optimal for the terminal, and instruct a change to that beam. The following describes the procedure for instructing the terminal to select the optimal beam via the unified TCI framework.

[0145] Although not shown in the drawing, the base station can set a unified TCI state for the terminal through RRC settings. Methods for setting the unified TCI state can be found in Tables 1 to 3 below.

[0146] 1. Joint UL / DL mode: Set UL and DL to share the same TCI settings (in PDSCH-Config)

[0147] [Table 1]

[0148]

[0149] 2. Separate UL / DL mode: The UL and DL each provide their own TCI configurations. The TCI state for the DL follows the configuration in dl-OrJoint-TCIStateList-r17 (in PDSCH-Config), and the TCI state for the UL follows ul-TCI-StateList-r17 (in BWP-UplinkDedicated).

[0150] [Table 2]

[0151]

[0152] [Table 3]

[0153]

[0154] Note that the beam indicated in the unified TCI state can also indicate the TCI state in a cell (additionalPCI-r17) that has a different physical cell dientity (PCI) from the serving cell.

[0155] In step 1f-05, the base station can instruct the terminal to activate one or more TCI states through a unified TCI state activation / deactivation MAC (medium access control) CE (control element).

[0156] 1f-01 is a diagram illustrating the structure of a unified TCI state MAC CE. As illustrated in the diagram, the MAC CE (1f-01) can indicate multiple TCI states indicated by a serving cell and UL (uplink) / DL (downlink) BWP (bandwidth part). Here, the P field is an indicator indicating whether the indicated unified TCI state is indicated separately for uplink / downlink. For a description of the P field, refer to the description below.

[0157]

[0158] In step 1f-10, the base station can indicate a single unified TCI state to be applied to the UE via downlink control information (DCI). Note that if only one TCI state code point is transmitted in the MAC CE in step 1f-05, the UE can activate the corresponding TCI state without receiving a DCI. The DCI may schedule a downlink PDSCH or indicate only a beam without scheduling a PDSCH.

[0159] If the downlink PDSCH is scheduled in the DCI, PDSCH transmission is accompanied by steps 1f-15. If the downlink PDSCH is not scheduled in the DCI, steps 1f-15 can be omitted without a separate PDSCH transmission.

[0160] Thereafter, in step 1f-20, the terminal can transmit an ACK (acknowledgment) signal indicating that it has successfully received the DCI or PDSCH received from the base station through PUCCH.

[0161] In reality, the terminal can apply the indicated unified TCI state to all uplink and downlink channels (PDCCH / PDSCH / PUCCH / PUSCH) after a time equal to BAT (Beam Application Time; 1f-25) has passed since transmitting the ACK signal through PUCCH. The terminal can use the previously used TCI state as it is until the first slot after a time equal to BAT (1f-25) has passed since transmitting the ACK signal through PUCCH. For transmissions of all channels (1f-40, 1f-45) after (1f-35), a new beam indicated to be activated with the unified TCI state can be applied (1f-50).

[0162] FIG. 1g is a diagram illustrating a method in which a unified transmission configuration indication (TCI) state is applied to multiple transmission reception points (TRPs) according to one embodiment of the present disclosure.

[0163] Referring to FIG. 1g, rules applicable to multiple TRPs (multiple TRPs) by applying the improved unified TCI state structure proposed in the present disclosure are described. More specifically, it describes how a terminal manages and applies each TCI state (1g-05, 1g-10) indicated in two TRPs when it is indicated and updated by a medium access control (MAC) control element (CE) or downlink control information (DCI). In addition, for this purpose, a method of applying different activated beams for each channel by applying the channel-specific TCI state application techniques (semi-static RRC configuration, new TCI selection field in DCI) applicable throughout the present disclosure is described.

[0164] In a unified TCI state-activated MAC CE for supporting multiple TRPs based on a single physical downlink control channel (PDCCH) according to an embodiment of the present disclosure, it must be indicated whether the TCI state mapped and indicated by the TCI codepoint is from the first TRP, the second TRP, both are applicable, or neither is applicable. The TCI state application rules applied in the present disclosure are described through FIG. 1g.

[0165] The terminal can receive the initially applied TCI codepoint {TCI#1 (1g-15), TCI#2 (1g-20)} through MAC CE or DCI, and store and manage the received TCI states as activated TCI states. At this time, the two TCI states indicated by the TCI codepoint may be received from multiple TRPs. Alternatively, the two TCI states indicated by the TCI codepoint may be multiple TCI states indicated by one TRP.

[0166] Thereafter, the base station can indicate TCI codepoint {TCI#3, none} (1g-30) through a new MAC CE or DCI at T1 time (1g-25). The terminal that receives TCI codepoint {TCI#3, none} through the new MAC CE or DCI can apply and manage the beam to be effectively applied as {TCI#3, TCI#2} (1g-35, 1g-40) in the next step.

[0167] It should be noted here that the beam that the terminal is effectively applying is not the indicated TCI codepoint {TCI#3, none}. The indicated TCI codepoint indicates the TCI state that the terminal needs to update, but if it is “none” (no TCI indicated), the terminal will keep the previously indicated TCI state. That is, since the first TCI is indicated as “TCI#3”, the terminal updates from the existing TCI#1 to TCI#3, whereas since the second TCI is indicated as “none”, the terminal will keep the previously indicated TCI state, TCI#2.

[0168] The same rule applies so that the terminal can receive TCI codepoint {none, TCI#4} (1g-50) via new MAC CE or DCI at time T2 (1g-45). The terminal that receives TCI codepoint {none, TCI#4} (1g-50) via new MAC CE or DCI can apply and manage the beam to be applied effectively in the next step as {TCI#3, TCI#4} (1g-55, 1g-60).

[0169] Additionally, at T3 time (1g-65), the terminal can receive TCI codepoint {TCI#5, TCI#6} (1g-70) through a new MAC CE or DCI. The terminal that receives this can apply and manage the beam to be effectively applied in the next step as {TCI#5, TCI#6} (1g-75, 1g-80).

[0170] The reason for introducing the above rule and the method for activating different TCI states applied to each actual channel are as follows. The Unified TCI state is a structure for applying a common beam change method applied to all channels, as described above in Figure 1f, and the indicated TCI state is applied to all channels after the beam application time (BAT).

[0171] Meanwhile, in actual implementations, there may be cases where not all channels use the same beam. Furthermore, certain channels may not be eligible for multiple TCI states. To address this, the present invention introduces a comprehensive TCI state application rule, requiring an operation that indicates the TCI state to be applied semi-statically or dynamically for each channel. Table 4 below summarizes how TCI states are indicated for each channel.

[0172] [Table 4] Application of unified TCI state by channel

[0173]

[0174] In particular, for the PDSCH reception beam indication method through DCI format 1_1 / 1_2, the active beam used for the corresponding channel reception can be dynamically indicated through the newly introduced “TCI selection field” (1g-85) in DCI.

[0175] If only one TCI codepoint is indicated in the MAC CE, there may not be a separate DCI beam indication, so in this case, all beams indicated through the MAC CE can be considered activated. Alternatively, a semi-static indication method for PDSCH reception may exist as an RRC setting, or the semi-static indication method applied to PDCCH reception may be applied as is to PDSCH reception. Here, the TCI selection field (1g-85) is a 2-bit newly introduced in DCI 1_1 / 1_2, and can indicate the following states.

[0176] - 00: Activate the first TCI state among the indicated TCI states.

[0177] - 01: Activate the second TCI state among the indicated TCI states.

[0178] - 10: Activate both TCI states of the indicated TCI state.

[0179] - 11: Exists as a reserved value

[0180] FIG. 1h is a diagram illustrating a method of transmitting and receiving data by applying a unified transmission configuration indication (TCI) framework according to an embodiment of the present disclosure.

[0181] More specifically, FIG. 1h illustrates the entire procedure of applying a data enhancement technique through multiple TRPs based on a single PDCCH (DCI) by applying a unified TCI framework in a NR (new radio) system.

[0182] NR systems are designed to use directional beams to transmit and receive data between terminals and base stations. Data communication via directional beams offers the advantage of high data rates, thanks to the wide bandwidth and resources afforded by the use of high frequencies. However, this can present limitations, such as the need to precisely direct the directional beams.

[0183] In NR systems, terminals measure synchronization signals via SS (synchronization signal) / PBCH (physical broadcast channel) blocks during the initial connection phase, and data transmission and reception can be performed along the beam direction where the synchronization signal is detected. Subsequently, a beam management technique can be applied to direct the terminal to the optimal beam based on Layer 1 channel measurement reports received by the base station from the terminal.

[0184] The beam management method proposed in this disclosure describes the entire procedure performed through unified TCI state indication, and is composed of a radio resource control (RRC) configuration step, a step of activating multiple candidate TCI states through a medium access control (MAC) control element (CE), and a step of indicating a beam for actual data transmission and reception through downlink control information (DCI).

[0185] As described above, the unified TCI state structure differs from the existing TCI state framework in that it can indicate and use a common TCI state in both uplink and downlink. Detailed operations of the unified TCI state framework according to an embodiment of the present disclosure are described in FIGS. 1f and 1g.

[0186] At step 1h-05, a terminal (1h-01) in a sleep mode (RRC_IDLE) may camp on a specific base station / cell (1h-02) and perform an RRC connection procedure to the base station, PCell (1h-02) due to reasons such as the occurrence of data to be transmitted. The specific base station / cell (1h-02) may include at least one transmission reception point (TRP). For example, the specific base station / cell (1h-02) may include TRP1 (1h-03) and TRP2 (1h-04).

[0187] In the above sleep mode, the terminal is not connected to the network to save power, so data cannot be transmitted. To transmit data, a transition to connected mode (RRC_CONNECTED) is required.

[0188] Additionally, the above-mentioned terminal camping on a specific base station / cell means that the terminal is staying in that cell and receiving paging messages to determine whether data is coming in the downlink.

[0189] In step 1h-10, if the terminal (1h-01) succeeds in the connection procedure to the base station (1h-02), the terminal (1h-01) changes its status to connection mode (RRC_CONNECTED), and the terminal (1h-01) in the connection mode can transmit and receive data with the base station (1h-02).

[0190] At step 1h-15, the terminal (1h-01) in the above-mentioned connection state can perform a procedure for reporting terminal capabilities with the base station (1h-02).

[0191] More specifically, the terminal (1h-01) can receive a terminal capability report request message from the base station (1h-02). The terminal capability report request message can be transmitted via an RRC message.

[0192] Thereafter, the terminal (1h-02) that has received the terminal capability report request message can generate a terminal capability information message (e.g., UECapabilityInformation) in response to the RRC message (or the terminal capability report request message) and report it to the base station (1-02).

[0193] The above terminal capability report RRC message may include a terminal capability indicating whether the terminal supports multiple DCI-based TRP techniques (hereinafter referred to as “sDCI-based mTRP operations”) within the unified TCI state framework. The terminal capability may be reported in one of several ways, such as on a per-terminal basis, per-band basis, or per-band combination basis.

[0194] Thereafter, at step 1h-20, the terminal (1h-01) can receive an RRC message including Multi TRP configuration information and / or unified TCI configuration information.

[0195] More specifically, the terminal (1h-01) can receive settings (config) related to a data communication enhancement technique through unified TCI and multiple TRPs (Multiple TRPs, mTRP) from the base station (1h-02), and perform a procedure for changing to an optimal beam for the corresponding operation.

[0196] At step 1h-20, the terminal (1h-01) can set a unified TCI state for each BWP of the serving cell through RRC configuration. (Up to 128 beams can be set)

[0197] The above terminal can directly configure the unified TCI state applied to the uplink and downlink in steps 1h-20. Alternatively, it can receive the serving cell and BWP indicators for which the configuration is provided and apply them. Unified TCI state mode (Joint TCI state mode or Separate TCI state mode) can also be configured at the same time. The specific details can be as shown in [Table 5] ASN.1 below.

[0198] Additionally, parameters related to data communication enhancement techniques through multiple TRPs can also be set.

[0199] [Table 5]

[0200]

[0201] Additionally, in addition to the above unified TCI state settings, if multiple TCI states are indicated by MAC CE or DCI for each channel, a setting (applyIndicatedTCIState) indicating which TCI state to apply may be added for each channel. For detailed settings, refer to Table 4 in Fig. 1g.

[0202] Table 6 below shows an example of applyIndicatedTCIState in PDCCH, and the corresponding field can be newly set in the ControlResourceSet IE.

[0203] [Table 6]

[0204]

[0205] For reference, the followUnifiedTCI-State-r17 field set within the above ControlResourceSet (CORESET) is a field indicating whether the unified TCI state is applied in the corresponding ControlResourceSet.

[0206] When the followUnifiedTCI-State-r17 field is set (set to TRUE), the terminal can apply the beam indicated by the unified TCI state (the beam indicated by MAC CE or DCI) to PDCCH reception and PDSCH reception.

[0207] Meanwhile, if the followUnifiedTCI-State-r17 field is not set, the terminal cannot use the unified TCI state, and the Rel-15 / 16-based TCI state indication MAC CE is applied to PDCCH reception, and the Rel-15 / 16-based TCI state activation MAC CE and DCI-type beam indication are applied to PDSCH reception.

[0208] The association between the followUnifiedTCI-State-r17 field set in the ControlResourceSet above and the newly introduced applyIndicatedTCIState-r18 field can be performed in the following two ways.

[0209] 1. First unified TCI framework related behavior: The new unified TCI state rule (applyIndicatedTCIState field setting) described in Table 4 of the above Figure 1g is applied only when the followUnifiedTCI-State-r17 setting and the related behavior are set (set to TRUE).

[0210] - applyIndicatedTCIState requires a condition that it can only be set when followUnifiedTCI-State-r17 is TRUE.

[0211] - Since the prerequisite of applyIndicatedTCIState is to set followUnifiedTCI-State-r17, the new unified TCI state rule (setting the applyIndicatedTCIState field) in this disclosure can only operate when the existing followUnifiedTCI-State related operation is performed.

[0212] - Switching between the followUnifiedTCI-State operation and the new unified TCI state rule (applyIndicatedTCIState field setting) operation is possible without separate RRC configuration. That is, the switch is possible by the base station transmitting the MAC CE for each function to the terminal, and the terminal can perform the operation accordingly.

[0213] 2. Second unified TCI framework related behavior: The unified TCI state rule (applyIndicatedTCIState field setting) described in Table 4 of the above Figure 1g is applied regardless of whether the followUnifiedTCI-State-r17 setting and related behavior are set.

[0214] - applyIndicatedTCIState can be set whether or not followUnifiedTCI-State-r17 is set.

[0215] - Since the prerequisite of applyIndicatedTCIState is not the followUnifiedTCI-State-r17 setting, the new unified TCI state rule (setting the applyIndicatedTCIState field) in this disclosure can be determined only by the presence of the field.

[0216] - If there is no followUnifiedTCI-State setting and only a new unified TCI state rule (applyIndicatedTCIState field setting) operation is set, the base station must reset it through a separate RRC reset when a switch to the followUnifiedTCI-State related operation is required. That is, the function switching is possible by the base station performing RRC reconfiguration for each function and then transmitting MAC CE to the terminal, and the terminal performs the operation accordingly.

[0217] Additionally, regardless of whether the above methods are applied, the terminal behavior when the new unified TCI state rule (applyIndicatedTCIState field setting) is applied may be as follows.

[0218] - If the applyIndicatedTCIState field indicates 'first', 'second', or 'both', the terminal can apply the indicated beam to PDCCH reception through the corresponding CORESET.

[0219] - On the other hand, if the applyIndicatedTCIState field indicates 'none', the terminal does not use any beam indicated by the unified TCI state (indicated by MAC CE or DCI) for PDCCH reception through the corresponding CORESET.

[0220] At step 1h-25, the base station (1h-02) can transmit a unified TCI MAC CE to the terminal (1h-01).

[0221] More specifically, the base station (1h-02) can instruct the terminal to activate multiple beams using MAC CE for the unified TCI state set by the RRC message. At this time, TCI states for up to 8 beam groups (when viewing the uplink and downlink as one group) can be activated.

[0222] The purpose of the above MAC CE can be understood as a process of selecting candidate beams that can be dynamically indicated by DCI during the TCI state setup set by RRC, and can reduce the number of TCI states that the terminal must manage and the number of bits indicated in DCI.

[0223] In particular, the new MAC CE structure proposed in this disclosure can be introduced at step 1h-25. The MAC CE used may vary depending on whether the aforementioned data communication enhancement technique using multiple TRPs is based on single PDCCHs or on multiple TRPs based on multi-PDCCHs. The detailed MAC CE structure is described later in Drawing 1i.

[0224] At step 1h-30, the terminal (1h-01) and the base station (1h-02) can transmit and receive DCI and ACK information for Unified TCI indication.

[0225] More specifically, the terminal can indicate a specific beam among the candidate beams indicated by the MAC CE through an indicator of the DCI. The indicator indicating the specific beam can be composed of 3 bits. The DCI used in step 1h-30 actually indicates a different beam depending on the type of MAC CE previously received by the terminal. In case of multiple TRP operations based on single PDCCH, multiple beams can be indicated in one DCI. On the other hand, in case of multiple TRP operations based on multi PDCCH, only one beam can be indicated in one DCI, so DCI reception is required for each TRP.

[0226] In addition, if the terminal has received DCI and the PDSCH reception scheduled by the DCI has been performed well, the terminal (1h-01) can transmit (or transmit) an ACK for the reception to the base station (1h-02) via PUCCH.

[0227] If there is only one TCI codepoint included in the MAC CE in step 1h-25, step 1h-30 can be omitted. That is, the TCI codepoint indicated by the MAC CE can be activated immediately.

[0228] The actual beam settings set and indicated in steps 1h-20 and 1h-25 above are set for each BWP. That is, the entire operation described above can be applied to one serving cell (or TRP) and one BWP belonging to the cell. If the beam settings for another serving cell and a specific BWP of the serving cell are to be changed, the entire operation described above can be repeated for the corresponding cell.

[0229] Since multiple cells may have the same beam configuration, this repetitive operation can be omitted and the beam configurations of multiple serving cells can be updated / activated simultaneously. Updating / activating the beam configurations of multiple serving cells simultaneously not only reduces the delay caused by the repetitive operation, but also significantly reduces the signaling overhead. Therefore, the base station can transmit a group (cell list) that can simultaneously update and activate the same beam configuration through the RRC configuration so that when the above procedure is performed, TCI state activation can also occur simultaneously for multiple cells having the same beam configuration.

[0230] In step 1h-35, the terminal (1h-02) can apply the indicated unified TCI state to all channel transmission and reception.

[0231] More specifically, through the above procedure, the Unified TCI state is indicated through DCI, and until the terminal transmits PUCCH ACK in response thereto, the terminal performs data transmission and reception by applying the beam (TCI state) previously used.

[0232] The actual time at which the indicated TCI state is applied is the first slot (1h-35) after the UE transmits a PUCCH ACK and the time equal to the beam application time (BAT) has elapsed. In other words, depending on which mode of the data communication enhancement technique using multiple TRPs is applied, the time at which the indicated beam is applied and the corresponding data transmission and reception operations may vary. Furthermore, the beam activated at that time may vary depending on the semi-statically set applied TCI state for each transmission channel.

[0233] Thereafter, at step 1h-40, the base station (1h-02) can instruct the terminal to change the unified TCI technique. The unified TCI technique change can be performed by resetting the RRC or transmitting the MAC CE for another purpose. The terminal can apply a data communication enhancement technique using a plurality of preset TRPs via the instructed beam.

[0234] FIGS. 1a to 1if are diagrams illustrating the structure of a medium access control (MAC) CE (control element) according to one embodiment of the present disclosure.

[0235] Referring to FIGS. 1ia to 1if, a MAC CE structure that activates a unified TCI state to support an enhanced data transmission and reception technique through multiple TRPs based on a single DCI (downlink control information) proposed in the present disclosure is illustrated.

[0236] According to one embodiment of the present disclosure, based on the currently defined “Unified TCI States Activation / Deactivation MAC CE (1f-01)”, a new MAC CE can be introduced and a new field can be added to support an improved data transmission / reception technique (multiple PDSCH transmission based on a single PDCCH) through multiple TRPs.

[0237] The existing MAC CE structure is composed of a serving cell ID, UL / DL BWP ID as described in 1f-01, a bitmap “Pi” field indicating whether both uplink / downlink TCI states exist, and a D / U, TCI state index. Through the existing MAC CE, a unified TCI state, i.e., a beam, can be indicated from a single serving cell / BWP.

[0238] Note that the unified TCI state can indicate the TCI state defined in the neighboring cells, so beam indication that exists between cells is possible. However, as can be seen from the MAC CE structure, since this operation indicates a candidate beam that can be used in a single TRP within a single serving cell / BWP, it cannot indicate beams (TCI states) applicable to multiple TRPs. Accordingly, if the existing MAC CE structure is followed, multiple TRP operations based on a single PDCCH cannot be supported.

[0239] In this disclosure, a beam direction method is proposed to support an improved data transmission / reception technique (multiple PDSCH transmission based on a single PDCCH) through multiple TRPs as described above, and in particular, this drawing describes a MAC CE design for this.

[0240] Basically, since the unified TCI state framework is used to direct beams, the basic unified TCI state procedure described in Fig. 1f (setting all candidate beams with RRC, activating beams with MAC CE, and directing beams with DCI) can be applied as is. However, the difference is that, while the activation and directing of the existing unified TCI state was only possible for a single TRP, the present disclosure allows beams to be directed to multiple TRPs using the unified TCI state.

[0241] Some things to consider when directing beams using a unified state across multiple TRPs include the maximum number of TCI states that can be directed per cell / BWP, the types of TCI states that can be applied across different TRPs (e.g., the resources referenced by the TCI state (synchronization signal block (SSB), channel status information-reference signal (CSI-RS), sounding reference signal (SRS), etc.), and most importantly, how to distinguish which mode to operate in via the MAC CE).

[0242] In addition, for repetition-based multiple TRP operations, which TRP can be transmitted in relation to which TCI state repetition resource can be configured through RRC configuration, and operations can be performed accordingly. The operation after RRC configuration varies depending on whether the terminal performs multiple PDSCH transmissions based on a single PDCCH, and the related MAC CE and DCI can be received to receive related beam instructions. That is, the unified TCI state applied to the terminal is determined according to the rules for applying the unified TCI state framework described in Drawing 1g and the rules for indicating the beams actually activated in each channel (semi-static instructions due to RRC configuration or instructions through the TCI selection field).

[0243] In FIG. 1ia to FIG. 1if, two MAC CE designs are proposed by applying the above-described considerations for the MAC CE design (1i-05) for multiple PDSCH transmissions based on a single PDCCH using a unified TCI state. However, the scope of the present invention is not limited thereto, and it is disclosed that all MAC CE designs that are designed by expanding from the design core elements described in the broad framework in addition to the MAC CE design proposed in the present invention can be included. In addition, the scope of the present invention includes both cases where the unified TCI state framework is set to the Joint TCI state mode and the Separate TCI state mode for each MAC CE design method.

[0244] 1) 1st MAC CE design method (1i-05)

[0245] - This is a method of scheduling data transmission through two TRPs together on one PDCCH and performing data transmission and reception accordingly. Therefore, a method is required to indicate the beam (TCI state) applied to data transmission and reception of two TRPs on one PDCCH together through a unified TCI state. That is, since beams for two TRPs are indicated on one PDCCH, one MAC CE and DCI transmission are required to indicate the beams for the two TRPs. Note that if only one TCI codepoint (TCI state for a set of TRP1 and TRP2) is indicated in the MAC CE, the TCI codepoint indication through the DCI is omitted.

[0246] ■ Up to 8 TCI state codepoints can be indicated (the number can be increased further). Here, the term "codepoint" refers to a case where both uplink / downlink TCI state indications are indicated in up to two TRPs, which are considered as one codepoint. In other words, if both TRPs are applied and uplink and downlink beams are indicated in all TCI states, up to 32 TCI states can be indicated by MAC CE.

[0247] - MAC CE design method

[0248] ■ Option A-1 (Figure 1i-10): MAC CE when set to Separate TCI state mode

[0249] ◆ TCI state mapping pattern (refer to table 1i-20)

[0250] ● As previously mentioned, a single TCI codepoint can consist of TCI states indicated for TRP1 and TRP2. In addition, when the Separate TCI state mode is set, the TCI states applicable to UL and DL must be indicated separately, so a single TCI codepoint must indicate up to four TCI states.

[0251] ● To express this, the P_ij field is introduced, and the P_ij field consists of 4 bits. That is, it is expressed as {DL TCI state of TRP1, UL TCI state of TRP1, DL TCI state of TRP2, UL TCI state of TRP2} and is expressed in each row of Table 1i-20. A total of 16 cases consisting of 4 bits must be covered, and the P_ij field expresses this.

[0252] ● Here, the index j is an indicator for indicating each bit in a total of 4 bits, and the index i is for indicating the TCI codepoint index. If up to 8 TCI codepoints are supported, the i value has a maximum of 8.

[0253] ◆ Other fields existing within MAC CE

[0254] ● CodePoint field (3 bits; 1i-30): This is an indicator to indicate how many TCI codepoints are indicated. Depending on this value, the P_ij field (1i-40) and TCII state ID field (1i-50) below are determined.

[0255] ● P_ij field (4 bits for each TCI codepoint, up to 32 bits; 1i-40): Field indicating the TCI state mapping pattern (Table 1i-20), see the description above.

[0256] ● TCI state ID (7bit; 1i-50): A TCI state indicated through the unified TCI state TCI framework. In the case of DL, it indicates the TCI state ID indicated by dl-orJoint-TCI-State, and in the case of UL, it indicates the TCI state ID indicated by TCI-UL-State. The TCI state indicated by the TCI codepoint is determined according to the CodePoint and P_ij fields.

[0257] ● Other fields (e.g. serving cell ID, BWP ID, etc.) use the same contents defined in the existing MAC CE.

[0258] ■ See Figure 1f-01

[0259] ■ Option A-2 (Figure 1i-60): MAC CE when set to Joint TCI state mode

[0260] ◆ TCI state mapping pattern (refer to 1i-70 table)

[0261] ● As previously mentioned, one TCI codepoint consists of TCI states indicated for TRP1 and TRP2. In addition, when the Joint TCI state mode is set, the TCI states applied to UL and DL must be indicated as a common TCI state, so a maximum of two TCI states must be indicated in one TCI codepoint.

[0262] ● To express this, the P_ij field is introduced, and the P_ij field consists of two bits. That is, it is expressed as {Joint TCI state of TRP1, Joint TCI state of TRP2} and is expressed in each row of Table 1i-20. A total of 16 cases consisting of 4 bits must be covered, and the P_ij field expresses this.

[0263] ● Here, the index j is an indicator for indicating each bit in a total of 2 bits, and the index i is for indicating the TCI codepoint index. If up to 8 TCI codepoints are supported, the i value has a maximum of 8.

[0264] ◆ Other fields existing within MAC CE

[0265] ● CodePoint field (3 bits; 1i-80): This is an indicator to indicate how many TCI codepoints are indicated. Depending on this value, the P_ij field (1i-90) and TCII state ID field (1i-100) below are determined.

[0266] ● P_ij field (2 bits for each TCI codepoint, maximum 16 bits; 1i-90): Field indicating the table TCI state mapping pattern (1i-70), see the description above.

[0267] ● TCI state ID (7bit; 1i-100): A TCI state indicated through the unified TCI state TCI framework. In the case of DL and UL, DL / UL are integrated and indicated through the Joint TCI state ID indicated as dl-orJoint-TCI-State. The TCI state indicated by the TCI codepoint is determined according to the CodePoint and P_ij fields.

[0268] ● Other fields (e.g. serving cell ID, BWP ID, etc.) use the same contents defined in the existing MAC CE.

[0269] ■ See Figure 1f-01

[0270] 2) 2nd MAC CE design method

[0271] ■ Option B-1 (Figure 1i-110): MAC CE when set to Separate TCI state mode

[0272] ◆ TCI state mapping pattern (refer to table 1i-120)

[0273] ● As previously mentioned, one TCI codepoint consists of TCI states indicated for TRP1 and TRP2. In addition, when the Separate TCI state mode is set, the TCI states applicable to UL and DL must be indicated separately, so a maximum of four TCI states must be indicated in one TCI codepoint.

[0274] ● To express this, the P_ij field is introduced, and the P_ij field consists of three bits. Here, referring to Table 1i-120, a bitmap that maps the number of TCI states indicated in the DL and the number of TCI states indicated in the UL for one TCI codepoint to all cases is defined, and this is expressed as the P_ij field.

[0275] ● For example, in the table, the number of DL TCI states can be from 0 to 2, and the number of UL TCI states can also be from 0 to 2, so when these are combined, 8 cases are generated, and the corresponding cases are mapped to the P_ij field.

[0276] ● Here, the index j is an indicator for indicating each case in a total of 3 bits, and the case of index i is for indicating the TCI codepoint index. If up to 8 TCI codepoints are supported, the i value has a maximum of 8.

[0277] ◆ Other fields existing within MAC CE

[0278] ● CodePoint field (3 bits; 1i-130): This is an indicator to indicate how many TCI codepoints are indicated. Depending on this value, the P_ij field (1i-140) and TCII state ID field (1i-150) below are determined.

[0279] ● P_ij field (3 bits for each TCI codepoint, maximum 24 bits; 1i-140): Field indicating the TCI state mapping pattern (Table 1i-120), see the description above.

[0280] ● TCI state ID (7bit; 1i-150): A TCI state indicated through the unified TCI stateTCI framework. In the case of DL, it indicates the TCI state ID indicated by dl-orJoint-TCI-State, and in the case of UL, it indicates the TCI state ID indicated by TCI-UL-State. The TCI state indicated by the TCI codepoint is determined according to the CodePoint and P_ij fields.

[0281] ● Other fields (e.g. serving cell ID, BWP ID, etc.) use the same contents defined in the existing MAC CE.

[0282] ■ See Figure 1f-01

[0283] ■ Option B-2 (Figure 1i-170): MAC CE when set to Joint TCI state mode

[0284] ◆ TCI state mapping pattern (refer to table 1i-180)

[0285] ● As explained above, one TCI codepoint consists of TCI states indicated for TRP1 and TRP2. In addition, when the Joint TCI state mode is set, the TCI states applied to UL and DL must be indicated as a common TCI state, so a maximum of two TCI states must be indicated in one TCI codepoint.

[0286] ● To express this, the P_ij field is introduced, and the P_ij field consists of two bits. Here, referring to Table 1i-180, a bitmap that maps the number of TCI states indicated in TRP1 and the number of TCI states indicated in TRP2 for one TCI codepoint to all cases is defined, and this is expressed as the P_ij field.

[0287] ● Here, the index j is an indicator for indicating each bit in a total of 2 bits, and the index i is for indicating the TCI codepoint index. If up to 8 TCI codepoints are supported, the i value has a maximum of 8.

[0288] ◆ Other fields existing within MAC CE

[0289] ● CodePoint field (3 bits; 1i-190): This is an indicator to indicate how many TCI codepoints are indicated. Depending on this value, the P_ij field (1i-200) and TCII state ID field (1i-210) below are determined.

[0290] ● P_ij field (2 bits for each TCI codepoint, maximum 16 bits; 1i-200): Field indicating the TCI state mapping pattern (Table 1i-180), see the description above.

[0291] ● TCI state ID (7 bits; 1i-210): A TCI state indicated through the unified TCI state TCI framework. In the case of DL and UL, DL / UL are integrated and indicated through the Joint TCI state ID indicated as dl-orJoint-TCI-State. The TCI state indicated by the TCI codepoint is determined according to the CodePoint and P_ij fields.

[0292] ● Other fields (e.g. serving cell ID, BWP ID, etc.) use the same contents defined in the existing MAC CE.

[0293] ■ See Figure 1f-01

[0294] FIG. 1J is a diagram illustrating the operation of a terminal according to an embodiment of the present disclosure.

[0295] In step 1j-05, the terminal can store terminal capabilities (or terminal capability information, UE capability information) and transmit (or transmit) them to the base station.

[0296] The terminal may transmit (or transmit) information including information regarding whether the terminal has the capability to support data transmission and reception enhancement techniques through multiple transmission reception points (TRPs) using the unified TCI framework. In particular, the terminal may transmit information including information related to support for multiple TRP operations based on a single DCI using the unified TCI framework.

[0297] The terminal can signal whether the feature is supported by band, band combination, or terminal. Furthermore, depending on the terminal's capabilities, the terminal can also include the ability to change beams for simultaneously applied cell groups by applying the unified TCI framework to cell groups.

[0298] In step 1j-10, the terminal can receive RRC (radio resource control) settings (e.g., RRCReconfiguration message) from the base station.

[0299] The above RRCReconfiguration message may include configuration information related to multiple TRP operations applying a unified TCI structure. That is, it may be configuration information related to a unified TCI state configuration and a PDSCH transmission technique based on a single PDCCH.

[0300] Additionally, RRC settings can be provided on a per-channel basis to semi-statically indicate the unified TCI state applied to the terminal. For detailed configuration information, refer to Drawing 1h-20.

[0301] Additionally to the above settings, cell group settings can be provided in connection with simultaneous beam update operations for multiple carriers. That is, the unified TCI framework is applied to cell groups to set the cells to which simultaneous beam changes are applied.

[0302] In step 1j-15, the terminal can receive an enhanced unified TCI state activation / deactivation MAC CE from the base station.

[0303] The above MAC CE may be a MAC CE (see Fig. 1i) for supporting multiple TRP operations based on a single PDCCH. The type of MAC CE received may vary depending on which unified TCI state mode is received through RRC settings.

[0304] In step 1j-20, the terminal can determine whether to apply the TCI state for each channel.

[0305] More specifically, the terminal receives a MAC CE (see FIGS. 1ia to 1if) for supporting a single PDCCH-based multiple TRP operation, and can determine whether a field for applying a TCI state per channel has been set in a previously received RRC configuration (e.g., an RRCReconfiguration message).

[0306] If a field for applying a TCI state per channel is set in the received RRC configuration (e.g., RRCReconfiguration message), in steps 1j-25, the terminal can activate the unified TCI state (TCI state indication for multiple TRPs) indicated in the received MAC CE. That is, beams associated with two TRPs can be activated by receiving a single MAC CE. When activating the beams, the unified TCI state application rule described above in FIG. 1g can be applied.

[0307] At step 1j-30, the terminal can receive DCI and apply the indicated beam after BAT.

[0308] More specifically, the terminal may receive a PDCCH (DCI) from the base station and be instructed to select one codepoint to be applied during actual data transmission and reception among the multiple beams activated in the above step. The codepoint may be composed of a unified TCI state used for TRP1 and TRP2, or may be composed solely of a TCI state for TRP1 and a TCI state for TRP2.

[0309] The above terminal may apply a beam or beams associated with the indicated codepoint after the beam application time (BAT). Additionally, a "TCI selection field" may be present in the above step to dynamically determine the beam applied to the PDSCH. The related operation is also referred to in Figure 1g-85.

[0310] In step 1j-35, the terminal can perform beam application and operation for each channel according to multiple TRP operation settings.

[0311] More specifically, the unified TCI state(s) indicated in the above step can be applied to data transmission and reception via multiple TRPs. That is, data communication can be performed via the indicated beam for channel transmission across the entire uplink and downlink.

[0312] In step 1j-20, the terminal can determine whether to apply the TCI state for each channel.

[0313] More specifically, the terminal may receive a MAC CE (see FIGS. 1ia to 1if) for supporting a single PDCCH-based multiple TRP operation, and determine whether a field for applying a TCI state per channel is set in a previously received RRC configuration (e.g., an RRCReconfiguration message).

[0314] If the field for applying TCI state per channel is not set in the received RRC configuration (e.g., RRCReconfiguration message), in step 1j-40, the terminal can activate the unified TCI state (TCI state indication for multiple TRPs) indicated in the received MAC CE according to the default application rule. That is, beams associated with two TRPs can be activated by receiving one MAC CE. Here, the beam default application rule can be a method of applying the beam indicated in the MAC CE to the entire channel as is or applying a specific beam defined in the standard (e.g., the first indicated beam).

[0315] At step 1j-45, the terminal can receive DCI and apply the indicated beam after BAT.

[0316] More specifically, the terminal may receive a PDCCH (DCI) from the base station and be instructed to select one codepoint to be applied during actual data transmission and reception among the multiple beams activated in the above step. The codepoint may be composed of a unified TCI state used for TRP1 and TRP2, or may be composed solely of a TCI state for TRP1 and a TCI state for TRP2.

[0317] The terminal may apply a beam or beams associated with the codepoint after the indicated BAT. Additionally, a "TCI selection field" may be present to dynamically determine the beam applied to the PDSCH in the above step. The related operation is also referred to in Figure 1g-85.

[0318] In step 1j-50, the terminal can perform beam application and operation for each channel according to multiple TRP operation settings.

[0319] More specifically, the terminal can apply the unified TCI state(s) indicated in the above step to data transmission and reception via multiple TRPs. That is, data communication can be performed via the indicated beam for channel transmission across the entire uplink and downlink.

[0320] FIG. 1k is a diagram illustrating the operation of a base station according to one embodiment of the present disclosure.

[0321] At step 1k-05, the base station can establish an RRC connection state with the terminal.

[0322] At step 1k-10, the base station can request terminal capability from the terminal and receive corresponding terminal capability information from the terminal.

[0323] The base station can analyze the terminal capabilities received at step 1k-10 to determine whether the terminal is capable of supporting data transmission and reception enhancement techniques through multiple TRPs (Multi-TRP) using the unified TCI framework. Furthermore, the base station can determine whether the terminal can configure data transmission and reception enhancement functions through multiple TRPs (Multi-TRP) using the unified TCI framework. The base station can also determine whether the functions are supported by band or by terminal.

[0324] Additionally, the base station can determine whether the terminal has the ability to simultaneously apply beam changes to the cell group by applying the unified TCI framework to the cell group according to the terminal's capability.

[0325] At step 1k-15, the base station can set up multiple TRP operations applying the unified TCI framework based on the terminal capabilities.

[0326] More specifically, after the terminal capability verification is completed, the base station can configure multiple TRP operations applying a unified TCI structure to the terminal according to the terminal capability through an RRC message in step 1k-15. This may be a configuration that supports PDSCH transmission based on a single PDCCH using a unified TCI state framework.

[0327] Additionally, in the above step, the base station can transmit unified TCI state related settings (or unified TCI state related settings information) to the terminal.

[0328] Additionally, if the terminal does not have the capability or the base station determines that the setting is not necessary, the terminal can support data enhancement techniques through multiple TRPs using the existing TCI state procedure.

[0329] Additionally, a new field (applyIndicatedTCIState) may be added to each channel to determine which unified TCI state to apply among the unified TCI states indicated for each channel. This is a setting that indicates which TCI state to apply when multiple TCI states are indicated for each channel via MAC CE or DCI in addition to the unified TCI state setting. For detailed settings, refer to Table 4 in FIG. 1g.

[0330] For reference, the followUnifiedTCI-State-r17 field set within the ControlResourceSet (CORESET) is a field indicating whether the unified TCI state is applied in the corresponding ControlResourceSet. If the followUnifiedTCI-State-r17 field is set (set to TRUE), the terminal can apply the beam indicated by the unified TCI state (the beam indicated by MAC CE or DCI) to PDCCH reception and PDSCH reception.

[0331] Meanwhile, if the followUnifiedTCI-State-r17 field is not set, the terminal cannot use the unified TCI state, and the Rel-15 / 16-based TCI state indication MAC CE is applied to PDCCH reception, and the Rel-15 / 16-based TCI state activation MAC CE and DCI-type beam indication can be applied to PDSCH reception.

[0332] The association between the followUnifiedTCI-State-r17 field set in the ControlResourceSet above and the newly introduced applyIndicatedTCIState-r18 field can be performed in two ways as described above in Fig. 1h-20. The base station can set applyIndicatedTCIState for each channel according to the determined method.

[0333] At step 1k-20, the base station may indicate beam activation by forwarding (or transmitting) a unified TCI MAC CE to support mTRP operation.

[0334] More specifically, the base station can instruct a beam update by transmitting a MAC CE for a beam update for a specific carrier and BWP based on the unified TCI framework set by the RRC, beam configuration information, and information about simultaneous beam update operations for multiple carriers.

[0335] The above beam-directing MAC CE may be one of the MAC CEs described in Drawing 1i. That is, it is intended to support a technique for enhancing data transmission and reception through multiple TRPs based on a single DCI using the unified TCI framework. If the unified TCI state is not configured, the above step may use the existing TCI state-activated MAC CE.

[0336] In the subsequent 1k-25 step, the base station can indicate and use beam information used for data communication by instructing activation of a beam for a BWP of a specific serving cell through DCI.

[0337] Thereafter, at step 1k-30, the base station can instruct the terminal to maintain the unified TCI state framework technique or, if it wants to change the function, to change the function by transmitting (or forwarding) the desired MAC CE transmission and resetting the RRC.

[0338] For example, if you want to maintain the unified TCI state framework technique or want to convert the functionality, this may include changing from the applyIndicatedTCIState-based unified TCI operation that worked in Rel-18 to support Rel-17 followUnifiedTCI-State-r17 unified TCI operation. The above MAC CE may include a Rel-17 unified TCI state MAC CE.

[0339] The detailed function conversion method can be determined according to the first unified TCI framework association operation and the second unified TCI framework association operation described above in FIG. 1h.

[0340] FIG. 1l is a block diagram illustrating the internal structure of a terminal according to one embodiment of the present disclosure.

[0341] Referring to the above drawing, the terminal includes an RF (Radio Frequency) processing unit (1l-10), a baseband processing unit (1l-20), a storage unit (1l-30), and a control unit (1l-40).

[0342] The RF processing unit (11-10) performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. That is, the RF processing unit (11-10) up-converts the baseband signal provided from the baseband processing unit (11-20) into an RF band signal and transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processing unit (11-10) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), etc. In the drawing, only one antenna is illustrated, but the terminal may be equipped with multiple antennas. In addition, the RF processing unit (11-10) may include multiple RF chains. Furthermore, the RF processing unit (11-10) may perform beamforming. For the above beamforming, the RF processing unit (11-10) can adjust the phase and size of each signal transmitted and received through multiple antennas or antenna elements. In addition, the RF processing unit can perform MIMO, and can receive multiple layers when performing the MIMO operation.

[0343] The baseband processing unit (11-20) performs a conversion function between a baseband signal and a bit stream according to the physical layer specifications of the system. For example, when transmitting data, the baseband processing unit (11-20) generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processing unit (11-20) restores the reception bit stream by demodulating and decoding the baseband signal provided from the RF processing unit (11-10). For example, in the case of following the OFDM (orthogonal frequency division multiplexing) method, when transmitting data, the baseband processing unit (11-20) generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols by performing an inverse fast Fourier transform (IFFT) operation and inserting a cyclic prefix (CP). In addition, when receiving data, the baseband processing unit (11-20) divides the baseband signal provided from the RF processing unit (11-10) into OFDM symbol units, restores signals mapped to subcarriers through FFT (fast Fourier transform) operation, and then restores the received bit string through demodulation and decoding.

[0344] The baseband processing unit (11-20) and the RF processing unit (11-10) transmit and receive signals as described above. Accordingly, the baseband processing unit (11-20) and the RF processing unit (11-10) may be referred to as a transmitter, a receiver, a transceiver, or a communication unit. Furthermore, at least one of the baseband processing unit (11-20) and the RF processing unit (11-10) may include a plurality of communication modules to support a plurality of different wireless access technologies. In addition, at least one of the baseband processing unit (11-20) and the RF processing unit (11-10) may include different communication modules to process signals of different frequency bands. For example, the different wireless access technologies may include a wireless LAN (e.g., IEEE 802.11), a cellular network (e.g., LTE), etc. Additionally, the different frequency bands may include a super high frequency (SHF) (e.g., 2.NRHz, NRhz) band and a millimeter wave (mm wave) (e.g., 60GHz) band.

[0345] The storage unit (1l-30) stores data such as basic programs, application programs, and setting information for the operation of the terminal. In particular, the storage unit (1l-30) can store information related to a second access node that performs wireless communication using a second wireless access technology. In addition, the storage unit (1l-30) provides the stored data at the request of the control unit (1l-40).

[0346] The above control unit (11-40) controls the overall operations of the terminal. For example, the control unit (11-40) transmits and receives signals through the baseband processing unit (11-20) and the RF processing unit (11-10). In addition, the control unit (11-40) records and reads data in the storage unit (11-40). For this purpose, the control unit (11-40) may include at least one processor. For example, the control unit (11-40) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as application programs.

[0347] FIG. 1m is a block diagram showing the configuration of an NR base station according to one embodiment of the present disclosure.

[0348] As shown in the above drawing, the base station is configured to include an RF processing unit (1m-10), a baseband processing unit (1m-20), a backhaul communication unit (1m-30), a storage unit (1m-40), and a control unit (1m-50).

[0349] The RF processing unit (1m-10) performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. That is, the RF processing unit (1m-10) up-converts the baseband signal provided from the baseband processing unit (1m-20) into an RF band signal and transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processing unit (1m-10) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. In the drawing, only one antenna is shown, but the first access node may have multiple antennas. In addition, the RF processing unit (1m-10) may include multiple RF chains. Furthermore, the RF processing unit (1m-10) may perform beamforming. For the above beamforming, the RF processing unit (1m-10) can adjust the phase and magnitude of each signal transmitted and received through multiple antennas or antenna elements. The RF processing unit can perform a downlink MIMO operation by transmitting one or more layers.

[0350] The baseband processing unit (1m-20) performs a conversion function between a baseband signal and a bit stream according to the physical layer specifications of the first wireless access technology. For example, when transmitting data, the baseband processing unit (1m-20) generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processing unit (1m-20) restores the reception bit stream by demodulating and decoding the baseband signal provided from the RF processing unit (1m-10). For example, in the case of OFDM, when transmitting data, the baseband processing unit (1m-20) generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols through IFFT operation and CP insertion. In addition, when receiving data, the baseband processing unit (1m-20) divides the baseband signal provided from the RF processing unit (1m-10) into OFDM symbol units, restores the signals mapped to subcarriers through FFT operation, and then restores the received bit string through demodulation and decoding. The baseband processing unit (1m-20) and the RF processing unit (1m-10) transmit and receive signals as described above. Accordingly, the baseband processing unit (1m-20) and the RF processing unit (1m-10) may be referred to as a transmitter, a receiver, a transceiver, a communication unit, or a wireless communication unit.

[0351] The above backhaul communication unit (1m-30) provides an interface for communicating with other nodes within the network. That is, the backhaul communication unit (1m-30) converts a bit string transmitted from the main base station to another node, such as an auxiliary base station or core network, into a physical signal, and converts a physical signal received from the other node into a bit string.

[0352] The storage unit (1m-40) stores data such as basic programs, application programs, and configuration information for the operation of the main base station. In particular, the storage unit (1m-40) can store information on bearers assigned to connected terminals, measurement results reported from connected terminals, and the like. In addition, the storage unit (1m-40) can store information that serves as a judgment criterion for whether to provide or terminate multiple connections to a terminal. In addition, the storage unit (1m-40) provides the stored data at the request of the control unit (1m-50).

[0353] The control unit (1m-50) controls the overall operations of the base station. For example, the control unit (1m-50) transmits and receives signals through the baseband processing unit (1m-20) and the RF processing unit (1m-10) or through the backhaul communication unit (1m-30). In addition, the control unit (1m-50) records and reads data in the storage unit (1m-40). For this purpose, the control unit (1m-50) may include at least one processor.

[0354] It should be noted that the configuration diagrams, exemplary diagrams of control / data signal transmission / reception methods, and exemplary diagrams of operational procedures illustrated in FIGS. 1A to 1M are not intended to limit the scope of the embodiments of the present disclosure. That is, not all components, entities, or operational steps described in FIGS. 1A to 4B should be construed as essential components for implementing the disclosure, and implementations may be made without detracting from the essence of the disclosure even if only some components are included.

[0355] The operations of the embodiments described above can be realized by providing a memory device storing program code in any component within the device. That is, the control unit within the device can execute the operations described above by reading and executing the program code stored in the memory device through a processor or a CPU (Central Processing Unit).

[0356] The various components and modules of the entity or terminal device described in the present disclosure may be operated using hardware circuits, such as logic circuits based on complementary metal oxide semiconductors, firmware, software, and / or hardware and firmware and / or software embedded in a machine-readable medium. For example, various electrical structures and methods may be implemented using electrical circuits such as transistors, logic gates, and application-specific semiconductors.

[0357] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0358] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of the present disclosure.

[0359] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage devices, compact disc-ROMs (CD-ROMs), digital versatile discs (DVDs) or other forms of optical storage devices, magnetic cassettes, or may be stored in memories formed by a combination of some or all of these. In addition, each configuration memory may include multiple copies.

[0360] Additionally, the program may be stored on an attachable storage device that is accessible via a communication network, such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device performing an embodiment of the present disclosure.

[0361] In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed in the singular or plural form, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in the plural form may be composed of singular elements, or components expressed in the singular form may be composed of plural elements.

[0362] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. A method performed by a terminal in a wireless communication system, A step of receiving, from a base station, a radio resource control (RRC) message including information related to at least one transmission configuration indictor (TCI) state; A step of receiving, from the base station, media access control (MAC) control information (control element, CE) for activating at least one TCI state, the MAC CE including first information corresponding to a first TCI state associated with at least one code point, second information corresponding to a second TCI state associated with the one code point, and TCI state identifier (ID) information according to the first information and the second information; A step of receiving downlink control information (DCI) including a TCI field indicating the one code point from the base station; and A method characterized by comprising a step of checking TCI state information related to a code point corresponding to the TCI field based on the RRC message and the MAC CE.

2. In paragraph 1, A method characterized in that the RRC message further includes information regarding which TCI state information among the first TCI state information and the second TCI information for at least one channel is to be applied.

3. In the first paragraph, if the TCI state is set to joint mode, The first information corresponding to the first TCI state includes third information corresponding to one of the downlink (DL) or uplink (UL), The second information corresponding to the second TCI state includes fourth information corresponding to one of the downlink or the uplink, A method characterized in that the TCI state identifier (ID) information according to the first information and the second information is set to a maximum of 16.

4. In the first paragraph, if the TCI state is set to separate mode, The first information corresponding to the first TCI state includes fifth information corresponding to the downlink (DL) and sixth information corresponding to the uplink (UL). The second information corresponding to the second TCI state includes seventh information corresponding to the downlink and eighth information corresponding to the uplink, A method characterized in that the TCI state identifier (ID) information according to the first information and the second information is set to a maximum of 32.

5. A method performed by a base station in a wireless communication system, A step of transmitting a radio resource control (RRC) message including information related to at least one transmission configuration indictor (TCI) state to a terminal; A step of transmitting, to the terminal, media access control (MAC) control information (control element, CE) for activating at least one TCI state, the MAC CE including first information corresponding to a first TCI state associated with at least one code point, second information corresponding to a second TCI state associated with the one code point, and TCI state identifier (ID) information according to the first information and the second information; A step of transmitting downlink control information (DCI) including a TCI field indicating the one code point to the terminal, A method characterized in that TCI state information related to a code point corresponding to a TCI field included in the DCI is related to the RRC message and the MAC CE.

6. In paragraph 5, A method characterized in that the RRC message further includes information regarding which TCI state information among the first TCI state information and the second TCI information for at least one channel is to be applied.

7. In paragraph 5, if the TCI state is set to joint mode, The first information corresponding to the first TCI state includes third information corresponding to one of the downlink (DL) or uplink (UL) links, The second information corresponding to the second TCI state includes fourth information corresponding to one of the downlink or the uplink, A method characterized in that the TCI state identifier (ID) information according to the first information and the second information is set to a maximum of 16.

8. In paragraph 5, if the TCI state is set to separate mode, The first information corresponding to the first TCI state includes fifth information corresponding to the downlink (DL) and sixth information corresponding to the uplink (UL). The second information corresponding to the second TCI state includes seventh information corresponding to the downlink and eighth information corresponding to the uplink, A method characterized in that the TCI state identifier (ID) information according to the first information and the second information is set to a maximum of 32.

9. In a wireless communication system, at the terminal, A transceiver for transmitting and receiving signals; and A control unit coupled with the above transmitter and receiver, wherein the control unit comprises: Receive a radio resource control (RRC) message from a base station, the radio resource control (RRC) message including information related to at least one transmission configuration indictor (TCI) state, Receive, from the base station, media access control (MAC) control information (control element, CE) for activating at least one TCI state, wherein the MAC CE includes first information corresponding to a first TCI state associated with at least one code point, second information corresponding to a second TCI state associated with the one code point, and TCI state identifier (ID) information according to the first information and the second information; Receive downlink control information (DCI) including a TCI field indicating the one code point from the base station, A terminal characterized in that it checks TCI state information related to a code point corresponding to the TCI field based on the RRC message and the MAC CE.

10. In paragraph 9, A terminal characterized in that the RRC message further includes information regarding which TCI state information among the first TCI state information and the second TCI information for at least one channel is to be applied.

11. In the 9th paragraph, if the TCI state is set to joint mode, The first information corresponding to the first TCI state includes third information corresponding to one of the downlink (DL) or uplink (UL) links, The second information corresponding to the second TCI state includes fourth information corresponding to one of the downlink or the uplink, A terminal characterized in that the TCI state identifier (ID) information according to the first information and the second information is set to a maximum of 16.

12. In the 9th paragraph, if the TCI state is set to separate mode, The first information corresponding to the first TCI state includes fifth information corresponding to the downlink (DL) and sixth information corresponding to the uplink (UL). The second information corresponding to the second TCI state includes seventh information corresponding to the downlink and eighth information corresponding to the uplink, A terminal characterized in that the TCI state identifier (ID) information according to the first information and the second information is set to a maximum of 32.

13. In a base station in a wireless communication system, A transceiver for transmitting and receiving signals; and A control unit coupled with the above transmitter and receiver, wherein the control unit comprises: Transmitting a radio resource control (RRC) message to a terminal, the radio resource control (RRC) message including information related to at least one transmission configuration indictor (TCI) state, Transmitting, to the terminal, media access control (MAC) control information (control element, CE) for activating at least one TCI state, wherein the MAC CE includes first information corresponding to a first TCI state associated with at least one code point, second information corresponding to a second TCI state associated with the one code point, and TCI state identifier (ID) information according to the first information and the second information; Transmitting downlink control information (DCI) including a TCI field indicating the one code point to the terminal, A base station, characterized in that TCI state information related to a code point corresponding to a TCI field included in the DCI is related to the RRC message and the MAC CE.

14. In paragraph 13, A base station, characterized in that the RRC message further includes information regarding which TCI state information among the first TCI state information and the second TCI information for at least one channel is to be applied.

15. In paragraph 13, If the above TCI state is set to joint mode, The first information corresponding to the first TCI state includes third information corresponding to one of the downlink (DL) or uplink (UL), The second information corresponding to the second TCI state includes fourth information corresponding to one of the downlink or the uplink, The TCI state identifier (ID) information according to the above first information and the above second information is set to a maximum of 16, If the above TCI state is set to separate mode, The first information corresponding to the first TCI state includes fifth information corresponding to the downlink (DL) and sixth information corresponding to the uplink (UL). The second information corresponding to the second TCI state includes seventh information corresponding to the downlink and eighth information corresponding to the uplink, A base station, characterized in that the TCI state identifier (ID) information according to the first information and the second information is set to a maximum of 32.

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