Method and apparatus for transmitting and receiving signals by using multiple beams in a wireless communication system

Abstract

A method performed by a user equipment (UE) in a wireless communication system, comprising: receiving physical downlink shared channel (PDSCH) configuration information including a list of transmission configuration indicator (TCI) states from a base station (BS); receiving a PDSCH medium access control control element (MAC CE) including information indicating activation of at least one TCI state in the list from the BS; identifying whether the PDSCH MAC CE is a MAC CE capable of indicating two or more TCI states regarding one TCI code point; receiving downlink control information (DCI) including information indicating the TCI code point from the BS; and receiving data from the BS via the PDSCH based on the information indicating activation of at least one TCI state, the identified result, and the information indicating the TCI code point.

Description

Technical Field

[0001] The present disclosure relates to a method and apparatus for transmitting and receiving signals by using multiple beams in a wireless communication system. Background Art

[0002] Due to the commercialization of the fourth-generation (4G) communication system and the increase in multimedia services, an improved fifth-generation (5G) communication system or pre-5G communication system is being developed to keep up with the explosive growth in the demand for wireless data services. For this purpose, the 5G or pre-5G communication system is referred to as a super 4G network communication system or a post-long term evolution (LTE) system.

[0003] Implementing the 5G communication system in the super high frequency (millimeter wave (mmW)) band (such as the 60-GHz band) is being considered to increase the data transmission rate. To mitigate path loss and increase the transmission distance during radio wave propagation in the super high frequency band of the 5G communication system, various technologies such as beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antennas are being studied.

[0004] In addition, to improve the system network of the 5G communication system, various technologies are currently being developed, including evolved small cells, advanced small cells, cloud radio access network (cloud-RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multipoint (CoMP), and interference cancellation. In addition, for the 5G system, advanced coding modulation (ACM) schemes such as hybrid FSK and QAM modulation (FQAM) and SWSC (sliding window superposition coding) and advanced access technologies such as filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA), sparse code multiple access (SDMA), etc. are being developed.

[0005] In addition, the Internet has evolved from a human - centered network for creating and consuming information to the Internet of Things (IoT) network, in which distributed components such as objects exchange information with each other to process information. The Internet of Everything (IoE) technology already exists, where IoT technology is combined with technologies such as those for processing big data through connection with a cloud server. To implement IoT, technologies such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology are required. Therefore, recently, technologies such as sensor networks for interconnecting objects, machine - to - machine (M2M) communication, and machine - type communication (MTC) have been studied. In the IoT environment, intelligent Internet technology services can be provided to create new value for human life by collecting and analyzing data obtained from interconnected objects. Through the convergence and integration between existing information technology (IT) and various industries, IoT can be applied to various fields such as smart homes, smart buildings, smart cities, smart cars or connected vehicles, smart grids, healthcare, smart household appliances, advanced medical services, etc.

[0006] Therefore, various attempts are being made to apply the 5G communication system to the IoT network. For example, technologies used for 5G communication (including beamforming, MIMO, and array antennas) are used to implement technologies such as sensor networks, M2M communication, MTC, etc. The application of the above - mentioned cloud RAN as a big - data - processing technology is an example of the convergence between 5G and IoT technologies.

[0007] Due to the above - mentioned technical features and the development of wireless communication systems, various services can be provided. Therefore, in particular, a method capable of smoothly supporting communication by using multiple beams is required. Summary of the Invention

[0008] A method and apparatus capable of effectively providing services in a mobile communication system are provided. In addition, a method and apparatus for transmitting and receiving signals by using multiple beams are provided.

[0009] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments of the disclosure. Brief Description of the Drawings

[0010] To more fully understand the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts:

[0011] Figure 1A The structure of a Long - Term Evolution (LTE) system according to an embodiment of the present disclosure is shown;

[0012] Figure 1BShows a radio protocol architecture for an LTE system according to an embodiment of the present disclosure;

[0013] Figure 1C Shows the structure of a next-generation mobile communication system according to an embodiment of the present disclosure;

[0014] Figure 1D Shows a radio protocol architecture for a next-generation mobile communication system according to an embodiment of the present disclosure;

[0015] Figure 1E Shows the structure of a next-generation mobile communication system according to an embodiment of the present disclosure;

[0016] Figure 1F Shows a frame structure used in a New Radio (NR) system according to an embodiment of the present disclosure;

[0017] Figure 1G Shows the entire process of a base station (BS) in an NR system indicating a beam for a downlink signal transmitted via a Physical Downlink Shared Channel (PDSCH) according to an embodiment of the present disclosure;

[0018] Figure 1H Shows the entire process of a BS in an NR system indicating a beam group for a downlink signal transmitted in a PDSCH via multiple Transmission and Reception Points (TRPs) according to an embodiment of the present disclosure;

[0019] Figure 1I Shows a Media Access Control - Control Element (MAC CE) structure and a method for activating candidate downlink beam groups transmitted from multiple TRPs according to an embodiment of the present disclosure;

[0020] Figure 1J Shows a MAC CE structure and a method for activating candidate downlink beam groups transmitted from multiple TRPs according to an embodiment of the present disclosure;

[0021] Figure 1K Shows a MAC CE structure and a method for activating candidate downlink beam groups transmitted from multiple TRPs according to an embodiment of the present disclosure;

[0022] Figure 1L Shows a MAC CE structure and a method for activating candidate downlink beam groups transmitted from multiple TRPs according to an embodiment of the present disclosure;

[0023] Figure 1M Shows a method for a BS to configure a downlink beam group via multiple TRPs and communicate with a User Equipment (UE) according to an embodiment of the present disclosure;

[0024] Figure 1NA flowchart of UE operations according to an embodiment of the present disclosure is shown;

[0025] Figure 1O A flowchart of a BS according to an embodiment of the present disclosure is shown;

[0026] Figure 1P The internal structure of a UE according to an embodiment of the present disclosure is shown; and

[0027] Figure 1Q The configuration of a BS according to an embodiment of the present disclosure is shown. Detailed implementation manners

[0028] According to an embodiment of the present disclosure, a method performed by a user equipment (UE) in a wireless communication system includes: receiving physical downlink shared channel (PDSCH) configuration information including a list of transmission configuration indicator (TCI) states from a base station (BS); receiving a PDSCH medium access control - control element (MAC CE) including information indicating the activation of at least one TCI state in the list from the BS; identifying whether the PDSCH MAC CE is a MAC CE capable of indicating two or more TCI states of one TCI code point; and receiving data from the BS via the PDSCH based on the information indicating the activation of at least one TCI state, the identified result, and the information indicating the TCI code point.

[0029] Modes of the present invention

[0030] Before the following detailed description, it would be advantageous to set forth definitions of certain words and phrases used throughout this patent document: The terms "include" and "comprise" and their derivatives mean including but not limited to; the term "or" is inclusive and means and / or; the phrases "associated with" and "associated therewith" and their derivatives may mean including, being included within, interconnected with, containing, being contained within, connected to or coupled with, communicable with, cooperating with, interlacing, juxtaposing, adjacent to, bound to or bound with, having, having the property of, etc.; and, the term "controller" means any device, system or part thereof that controls at least one operation, and such a device may be implemented in hardware, firmware or software or some combination of at least two of them. It should be noted that the functions associated with any particular controller may be centralized or distributed, whether local or remote.

[0031] In addition, the various functions described below can be implemented or supported by one or more computer programs, each of which is formed of computer-readable program code and embodied in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, procedures, functions, objects, classes, instances, related data, or a portion thereof that are adapted to be implemented in suitable computer-readable program code. The phrase "computer-readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes any type of medium that can be accessed by a computer, such as read-only memory (ROM), random access memory (RAM), hard disk drive, compact disc (CD), digital video disc (DVD), or any other type of memory. A "non-transitory" computer-readable medium does not include a wired, wireless, optical, or other communication link that transmits transitory electrical or other signals. Non-transitory computer-readable media include media that can permanently store data and media that can store data and be rewritten later, such as a rewritable optical disc or an erasable memory device.

[0032] Throughout this patent document, definitions of particular words and phrases are provided. Those of ordinary skill in the art should understand that, in many if not most instances, such definitions apply to the prior as well as future use of such defined words and phrases.

[0033] As discussed below Figures 1A through 1Q and the various embodiments used to describe the principles of the present disclosure in this patent document are merely illustrative and should not be construed in any way as limiting the scope of the present disclosure. Those skilled in the art will understand that the principles of the present disclosure can be implemented in any suitably arranged system or device.

[0034] Throughout the disclosure, the expression "at least one of a, b, or c" means only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0035] The terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing communication functions.

[0036] In the present disclosure, the controller may also be referred to as a processor.

[0037] Throughout the specification, a layer (or layer device) may also be referred to as an entity.

[0038] Hereinafter, the operating principle of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description of the present disclosure, known functions or configurations are not described in detail because they would obscure the essence of the present disclosure with unnecessary details. In addition, the terms used herein are defined by considering the functions described in the present disclosure and may be changed according to the intention or practice of the user or operator. Therefore, the definition of the terms should be based on the overall description of the present disclosure.

[0039] As used in the following description, for ease of description, terms for identifying access nodes, terms for indicating network entities, terms for indicating messages, terms for indicating interfaces between network entities, terms for indicating various types of identification information, etc. are exemplified. Therefore, the present disclosure is not limited to the terms described later, and other terms representing objects having equivalent technical meanings may be used.

[0040] Hereinafter, a base station (BS) is an entity that allocates resources to a UE, and may be at least one of a gNodeB, an eNodeB, a NodeB, a BS, a radio access unit, a BS controller, or a network node. The term terminal may refer to a mobile phone, a narrowband Internet of Things (NB-IoT) device, a sensor, and other wireless communication devices. However, the BS and the terminal are not limited to the above examples.

[0041] Hereinafter, for ease of description, the present disclosure uses terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) and / or 3GPP New Radio (3GPP NR) specifications. However, the present disclosure is not limited to these terms and names, but may also be equally applied to systems conforming to other standards.

[0042] Since a post-LTE communication system, namely, a fifth-generation (5G) communication system, needs to be able to freely reflect various requirements from users and service providers, the 5G communication system needs to support services that can simultaneously meet various requirements. Services being considered for the 5G communication system include enhanced mobile broadband (eMBB), massive machine type communication (mMTC), ultra-reliable low-latency communication (URLLC), etc.

[0043] According to embodiments of the present disclosure, eMBB may be aimed at providing a higher data transfer rate than that supported by existing LTE, advanced LTE (LTE-A), or LTE-Pro. For example, in a 5G communication system, from the perspective of a base station (BS), eMBB can deliver a peak data rate of 20 gigabits per second (Gbps) in the downlink and 10 Gbps in the uplink. In addition, the 5G communication system can provide a better user-perceived data rate while delivering the peak data rate. To meet such requirements, the 5G communication system may need to improve various transmission / reception technologies, including further improved multiple-input multiple-output (MIMO) transmission technology. In addition, while the current LTE system transmits signals using a maximum transmission bandwidth of 20 megahertz (MHz) in the 2 GHz band, the 5G communication system can meet the data transfer rate required by 5G technology by using a frequency bandwidth wider than 20 MHz in the 3 GHz to 6 GHz band or a band above 6 GHz.

[0044] Meanwhile, mMTC is considered to support application services such as the Internet of Things (IoT) in the 5G communication system. To effectively provide the IoT, mMTC may need to support large-scale connection with terminals in the cell, enhanced terminal coverage, improved battery life, low terminal cost, etc. Since the IoT is a system equipped with multiple sensors and various devices to provide communication functions, the IoT can support a large number of terminals in the cell (e.g., one million terminals per square kilometer (km 2 )). In addition, because due to the characteristics of the service, the terminals supporting mMTC are likely to be located in shadow areas that cannot be covered by the cell (such as the basement of a building), mMTC may require wide-area coverage compared to other services provided by the 5G communication system. The terminals supporting mMTC can be configured as low-cost terminals and require a very long battery life (e.g., 10 to 15 years) because it is difficult to replace the battery of the terminal frequently.

[0045] Finally, URLLC is a cellular-based wireless communication service for mission-critical applications such as remote control of robots or machinery, industrial automation, unmanned aerial vehicles (UAVs), remote healthcare, emergency alert services, etc. Therefore, URLLC communication can provide very low latency (ultra-low latency) and extremely high reliability (ultra-high reliability). For example, the services supported by URLLC may have to meet the requirement of an air interface latency of less than 0.5 millisecond (ms) and, at the same time, have a packet error rate of less than 10 -5 of.

[0046] Therefore, in order to support URLLC services, the 5G system has to provide shorter transmission time intervals (TTIs) than other services and may also require designs for allocating wideband resources to ensure high reliability of the communication link.

[0047] The above three services considered in the 5G communication system (i.e., eMBB, URLLC, and mMTC) can be multiplexed in one system for transmission. Different transmission / reception techniques and transmission / reception parameters can be used between services to meet the different requirements of each service. However, mMTC, URLLC, and eMBB are merely examples of different service types, and the service types to which the present disclosure is applied are not limited to the above examples.

[0048] Although the embodiments of the present disclosure will be described below as examples of an LTE or LTE-LTE-A system, the embodiments of the present disclosure can be applied to other communication systems having a similar technical background and channel configuration. In addition, those skilled in the art should understand that the embodiments of the present disclosure are applicable to other communication systems with modifications made without departing from the scope of the present disclosure.

[0049] Hereinafter, the embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings.

[0050] Figure 1A The structure of an LTE system according to an embodiment of the present disclosure is shown.

[0051] Reference Figure 1A , the radio access network of the LTE system consists of evolved Node Bs (hereinafter referred to as eNBs, Node Bs, or BSS) 1a-05, 1a-10, 1a-15, and 1a-20, a Mobility Management Entity (MME) 1a-25, and a Serving Gateway (S-GW) 1a-30. A User Equipment (hereinafter referred to as "UE" or terminal) 1a-35 is connected to an external network via eNBs 1a-05 to 1a-20 and S-GW 1a-30.

[0052] In Figure 1AAmong them, eNBs 1a-05 to 1a-20 correspond to existing Node Bs in the Universal Mobile Telecommunications System (UMTS). Each of eNBs 1a-05 to 1a-20 is connected to UE 1a-35 via a radio channel and performs more complex functions than existing Node Bs. In the LTE system, since services for all user traffic including real-time services such as Voice over Internet Protocol (VoIP) services are provided on a shared channel, it may be necessary for an entity to perform scheduling by collecting status information such as the buffer status, available transmission power status, and channel status of a UE. Each of eNBs 1a-05 to 1a-20 may perform a scheduling function. One eNB generally controls multiple cells. For example, in order to achieve a data rate of 100 megabits per second (Mbps), the LTE system may utilize Orthogonal Frequency Division Multiplexing (hereinafter abbreviated as OFDM) in a 20 MHz bandwidth as a radio access technology. However, the radio access technology that the LTE system can use is not limited to the above example. In addition, eNBs 1a-05 to 1a-20 may apply Adaptive Modulation and Coding (hereinafter abbreviated as AMC) to determine a modulation scheme and a channel coding rate according to the channel status of a UE. S-GW 1a-30 is an entity for providing data bearers and creates or deletes data bearers under the control of MME 1a-25. MME 1a-25 is responsible for performing various control functions of a UE as well as mobility management and is connected to multiple BSs.

[0053] Figure 1B FIG. shows a radio protocol architecture for an LTE system according to an embodiment of the present disclosure.

[0054] Reference Figure 1B, the radio protocol stack of each of the UE and eNB in the LTE system may include Packet Data Convergence Protocol (PDCP) 1b-05 or 1b-40, Radio Link Control (RLC) 1b-10 or 1b-35, and Media Access Control (MAC) 1b-15 or 1b-30. PDCP 1b-05 or 1b-40 may be responsible for performing compression / decompression of IP headers. The main functions of PDCP 1b-05 or 1b-40 are summarized below, but are not limited thereto: header compression and decompression (only Robust Header Compression (ROHC)); delivery of user data; in-order delivery of higher layer packet data units (PDUs) during PDCP reconstruction for RLC acknowledged mode (AM); sequence reordering (for split bearers in dual connectivity (DC) (only supporting RLC AM): routing of PDCP PDUs for transmission and reordering of PDCP PDUs for reception); duplicate detection of lower layer service data units (SDUs) during PDCP reconstruction for RLC AM; retransmission of PDCP SDUs at handover, and for split bearers in DC, retransmission of PDCP PDUs during PDCP data recovery for RLC AM; encryption and decryption; timer-based SDU discard in the uplink; RLC 1b-10 or 1b-35 may reconfigure PDCP PDUs of appropriate size to perform Automatic Repeat reQuest (ARQ) operations. The main functions of RLC 1b-10 or 1b-35 may be summarized below, but are not limited thereto: delivery of upper layer PDUs; error correction by ARQ (only for AM data delivery); concatenation, segmentation, and reassembly of RLC SDUs (only for UM and AM data delivery); re-segmentation of RLC data PDUs (only for AM data delivery); reordering of RLC data PDUs (only for unacknowledged mode (UM) and AM data delivery); duplicate detection (only for UM and AM data delivery); protocol error detection (only for AM data delivery); RLC SDU discard (only for UM and AM data delivery); and RLC reconstruction.

[0055] MAC b-15 or b-30 is connected to multiple RLC layers configured in the UE, and can multiplex RLC PDUs into MAC PDUs and demultiplex RLC PDUs from MAC PDUs. The main functions of MAC b-15 or b-30 can be summarized as follows, but are not limited thereto: mapping between logical channels and transport channels; multiplexing MAC SDUs belonging to one or different logical channels into transport blocks (TBs) delivered to the physical layer on the transport channel / demultiplexing MAC SDUs belonging to one or different logical channels from transport blocks (TBs) delivered from the physical layer on the transport channel; scheduling information reporting; error correction via hybrid ARQ (HARQ); priority handling between logical channels of a UE; priority handling between UEs via dynamic scheduling; multimedia broadcast / multicast service (MBMS) service identification; transport format selection; and padding.

[0056] The physical layer (hereinafter also referred to as the PHY layer) 1b-20 or 1b-25 can transform high-layer data into OFDM symbols through channel coding and modulation and transmit the OFDM symbols via a radio channel, or transform the OFDM symbols received via the radio channel into high-layer data through demodulation and channel decoding and send the high-layer data to the high layer. In addition, HARQ is used for additional error correction in the physical layer, and on the receiving side, the UE sends a 1-bit indicator indicating whether the UE has received a packet from the transmitting side. The 1-bit indicator is referred to as HARQ acknowledgement (ACK) / negative acknowledgement (NACK). The downlink HARQ ACK / NACK for uplink transmission can be sent via the physical HARQ indicator channel (PHICH), while the uplink HARQ ACK / NACK for downlink transmission can be sent via the physical uplink control channel (PUCCH) or the physical uplink shared channel (PUSCH).

[0057] In addition, the PHY layer can be configured to use one or more frequencies / carriers, and the technology for simultaneously configuring and using multiple frequencies is referred to as carrier aggregation (CA). According to the CA technology, a primary carrier and one or more secondary carriers can be adopted in the communication between the UE and the BS (Evolved Universal Terrestrial Radio Access Network (E-UTRAN) NodeB or eNB), thereby significantly increasing the data rate in proportion to the number of secondary carriers adopted. In LTE, the cell using the primary carrier in the BS is referred to as the primary cell (PCell), and the cell using the secondary carrier is referred to as the secondary cell (SCell).

[0058] Although not shown in Figure 1B the radio resource control (RRC) layer can exist above the PDCP layer at each of the UE and the BS. The RRC layer can exchange connection and measurement configuration control messages for controlling radio resources.

[0059] Figure 1C shows the structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

[0060] Reference Figure 1C , the radio access network for the next-generation mobile communication system consists of a next-generation BS (i.e., a new radio node B (hereinafter referred to as NR NB, NR gNB, gNB, or NR BS) 1c-10 and an NR core network (NR CN) (or next-generation CN) 1c-05. The NR UE (or terminal) 1c-15 is connected to an external network via the NR NB 1c-10 and the NR CN 1c-05.

[0061] In Figure 1C , the NR NB 1c-10 corresponds to the eNB in the existing LTE system. The NR NB 1c-10 can be connected to the NR UE 1c-15 via a radio channel and provide a higher level of service than the existing node B. In the next-generation mobile communication system, since services for all user traffic are provided on a shared channel, an entity is required to perform scheduling by collecting status information such as the buffer status, available transmit power status, and channel status of the UE. The NR NB 1c-10 can perform this scheduling function. Generally, one NR NB controls multiple cells. According to an embodiment of the present disclosure, in order to provide ultra-high-speed data transmission compared to LTE, the next-generation mobile communication system can have a bandwidth wider than the existing maximum bandwidth and utilize OFDM as the radio access technology together with an additional beamforming technology. In addition, the NR NB 1c-10 can apply AMC to determine the modulation scheme and channel coding rate according to the channel status of the NR UE 1c-15. The NR CN 1c-05 can perform functions such as mobility support, bearer configuration, quality of service (QoS) configuration, etc. The NR CN 1c-05 is an entity responsible for performing various control functions and the mobility management of the UE and is connected to multiple BSs. In addition, the next-generation mobile communication system can operate in combination with the existing LTE system, and the NR CN 1c-OS is connected to the MME 1c-25 through a network interface. The MME 1c-25 is connected to the eNB 1c-30, which is an existing BS.

[0062] Figure 1D shows the radio protocol architecture for a next-generation mobile communication system according to an embodiment of the present disclosure.

[0063] Reference Figure 1D, the radio protocol stack of each of the UE and the NR base station in the next-generation mobile communication system includes NR Service Data Adaptation Protocol (NR SDAP) 1d-01 or 1d-45, NR PDCP 1d-05 or 1d-40, NR RLC 1d-10 or 1d-35, and NR MAC 1d-15 or 1d-30.

[0064] According to an embodiment of the present disclosure, the main functions of NR SDAP 1d-01 or 1d-45 may include some of the following. However, the functions of NR SDAP 1d-01 or 1d-45 are not limited to the following: delivery of user plane data; mapping between QoS flows and data radio bearers (DRBs) for both downlink and uplink; marking QoS flow IDs in both downlink packets and uplink packets; and reflection QoS flow to DRB mapping for uplink SDAP PDUs.

[0065] For the SDAP layer, the UE may receive, via an RRC message, configuration regarding whether to use the header of the SDAP layer or the functions of the SDAP layer for each PDCP layer, each bearer, or each logical channel. When the SDAP header is configured, the 1-bit non-access stratum (NAS) reflection QoS indicator and the 1-bit AS reflection QoS indicator in the SDAP header may instruct the UE to update or reconfigure information regarding the mapping between QoS flows and DRBs for uplink and downlink. The SDAP header may include QoS flow ID information identifying the QoS. In addition, according to an embodiment of the present disclosure, the QoS information may be used as priorities for data processing, scheduling information, etc. to support smooth services.

[0066] According to an embodiment of the present disclosure, the main functions of NR PDCP 1d-05 or 1d-40 may include some of the following functions. However, the functions of NR PDCP 1d-05 or 1d-40 are not limited to the following examples: header compression and decompression: only ROHC; delivery of user data; in-order delivery of upper layer PDUs; out-of-order delivery of upper layer PDUs; reordering of received PDCP PDUs; duplicate detection of lower layer SDUs; retransmission of PDCP SDUs; encryption and decryption; and timer-based SDU discard in the uplink.

[0067] According to an embodiment of the present disclosure, the reordering function of the NR PDCP entity may refer to the function of reordering PDCP PDUs received from the lower layer in the order of the PDCP sequence number (SN). The reordering function of the NR PDCP entity may include at least one of the following functions: the function of sending data to the upper layer in a rearranged order, the function of directly sending data to the upper layer without considering the order, the function of rearranging the order of PDCP PDUs and recording the lost PDCP PDUs, the function of submitting a status report indicating the lost PDCP PDUs to the sending side, and the function of requesting retransmission of the lost PDCP PDUs.

[0068] According to an embodiment of the present disclosure, the main functions of NR RLC 1d-10 or 1d-35 may include some of the following. However, the functions of NR RLC 1d-10 or 1d-35 are not limited to the following: delivery of upper layer PDUs; in-sequence delivery of upper layer PDUs; out-of-sequence delivery of upper layer PDUs; error correction by ARQ; concatenation, segmentation, and reassembly of RLC SDUs; re-segmentation of RLC data PDUs; reordering of RLC data PDUs; duplicate detection; protocol error detection; RLC SDU discard; and RLC reconstruction.

[0069] According to an embodiment of the present disclosure, the in-sequence delivery function of the NR RLC entity may refer to the function of sequentially sending RLC SDUs received from the lower layer to the upper layer. The in-sequence delivery function may include at least one of the following functions: the function of reassembling and sending multiple RLC SDUs when one RLC SDU is segmented into multiple RLC SDUs and received; the function of reordering received RLC PDUs based on the RLC SN or PDCP SN; the function of rearranging the order of RLC PDUs and recording the lost RLC PDUs; the function of submitting a status report indicating the lost RLC PDUs to the sending side; the function of requesting retransmission of the lost RLC PDUs; the function of sequentially sending only the RLC SDUs before the lost RLC SDU to the upper layer when there is a lost RLC SDU; the function of sequentially sending all RLC SDUs received before the restart of a given timer to the upper layer when the timer expires before the lost RLC SDU is received; or the function of sequentially sending all RLC SDUs received so far to the upper layer when a given timer expires before the lost RLC SDU is received.

[0070] In addition, according to an embodiment of the present disclosure, the NR RLC entity may process RLC PDUs in the order in which they are received (in the order of arrival, regardless of the sequence number or the order of the SN), and send the RLC PDUs to the PDCP entity regardless of their order (e.g., unordered delivery). Alternatively, the NR RLC entity may receive segmented or subsequently received segments stored in a buffer to reconfigure the segments into a complete RLC PDU, and then process the RLC PDU for transmission to the PDCP entity.

[0071] According to an embodiment of the present disclosure, the NR RLC layer may not include a concatenation function. The concatenation function may be performed in the NR MAC layer, or may be replaced by the multiplexing function of the NR MAC layer.

[0072] The unordered delivery function of the NR RLC entity refers to the function of directly sending RLC SDUs received from the lower layer to the upper layer regardless of their order. The unordered delivery function may include at least one of the following functions: the function of reorganizing and sending multiple RLC SDUs when one RLC SDU is segmented into multiple RLC SDUs and received; or the function of storing the RLC SN or PDCP SN of the received RLC PDUs, arranging the RLC PDUs in order according to the RLC SN or PDCP SN, and recording the lost RLC PDUs.

[0073] According to an embodiment of the present disclosure, NR MAC 1d-15 or 1d-30 may be connected to multiple NR RLC layers configured in the UE. The main functions of NR MAC 1d-15 or 1d-30 may include some of the following. However, the functions of NR MAC 1d-15 or 1d-30 are not limited to the following: mapping between logical channels and transport channels; multiplexing / demultiplexing of MAC SDUs; scheduling information reporting; error correction via HARQ; priority handling between logical channels of one UE; priority handling between UEs via dynamic scheduling; MBMS service identification; transmission format selection; and padding.

[0074] According to an embodiment of the present disclosure, the NR PHY layer 1d-20 or 1d-25 may transform the upper layer data into OFDM symbols through channel coding and modulation and send the OFDM symbols via a radio channel, or transform the OFDM symbols received via the radio channel into upper layer data through demodulation and channel decoding and send the upper layer data to the upper layer. However, the operations of the NR PHY layer 1d-20 or 1d-25 are not limited thereto.

[0075] Figure 1E The structure of a next-generation mobile communication system according to an embodiment of the present disclosure is shown.

[0076] Reference Figure 1E A cell served by an NR gNB 1e-05 based on beam operation may include multiple transmission and reception points (TRPs) 1e-10, 1e-15, 1e-20, 1e-25, 1e-30, 1e-35, and 1e-40. The TRPs 1e-10 to 1e-40 represent functional blocks that implement at least one function separated from the functions of an existing BS, such as a part of the function of transmitting and receiving physical signals, and each of the TRPs 1e-10 to 1e-40 includes multiple antennas.

[0077] According to an embodiment of the present disclosure, the NR gNB 1e-05 may be represented as a central unit (CU), and each TRP may be represented as a distributed unit (DU). The functions of the NR gNB 1e-05 and the TRP may both include Figure 1E some of the PDCP / RLC / MAC / PHY layers and the functions of the corresponding layers shown in 1e-45. For example, the TRPs 1e-15 and 1e-25 having only the PHY layer may perform the functions of the corresponding layers, the TRPs 1e-10, 1e-35, and 1e-40 having only the PHY layer and the MAC layer may perform the functions of the corresponding layers, and the TRPs 1e-20 and 1e-30 having only the PHY layer, the MAC layer, and the RLC layer may perform the functions of the corresponding layers.

[0078] According to an embodiment of the present disclosure, the TRPs 1e-10 to 1e-40 may use beamforming technology to generate narrow beams in various directions via multiple transmission and reception antennas for transmitting and receiving data. The user terminal 1e-60, i.e., the access and mobility management function (AMF) / session management function (SMF) 1e-50, may be connected to the NR gNB 1e-05 and the external network through the TRPs 1e-10 to 1e-40. To provide services to users, the NR gNB 1e-05 may schedule the UE based on the collected status information, such as the buffer status of the UE, the available transmission power status, and the channel status, and specifically, may support the connection between each UE and the CN, particularly the AMF / SMF 1e-50.

[0079] Figure 1F Shows a frame structure used in an NR system according to an embodiment of the present disclosure.

[0080] Reference Figure 1F Compared with the LTE system, the NR system aims at higher data rates and considers using high frequencies to ensure a wider frequency bandwidth. More specifically, a scenario of the NR system may be considered, where directional beams are generated at high frequencies and data is transmitted to the UE at a high rate by using the directional beams.

[0081] Therefore, a scenario can be considered where the NR gNB or TRP 1f-01 communicates with the first to fifth UEs 1f-71, 1f-73, 1f-75, 1f-77, and 1f-79 in the cell by using different beams for each UE. For example, in Figure 1F , the following scenario is assumed: the first UE 1f-71 communicates with the TRP 1f-01 using beam #1 1f-51, the second UE 1f-73 communicates with the TRP 1f-01 using beam #5 1f-55, and the third to fifth UEs 1f-75 to 1f-79 communicate with the TRP 1f-01 using beam #7 1f-57.

[0082] To identify the beam used by the UE to communicate with the TRP 1f-01, there is an overhead subframe (OSF) 1f-03 that sends a common overhead signal in the time domain. The OSF 1f-03 can include a primary synchronization signal (PSS) for obtaining the timing of OFDM symbols, a secondary synchronization signal (SSS) for detecting the cell identity (ID), etc. In addition, the base station can send a physical broadcast channel (PBCH) carrying system information, a master information block (MIB), or information necessary for the UE to access the system (e.g., downlink beam bandwidth, system frame number, etc.) to the UE. In addition, in the OSF 1f-03, the base station can send a reference signal by using different beams for each symbol (or over several symbols). The UE can derive a beam index for identifying each beam from the reference signal.

[0083] In Figure 1F , it is assumed that the NR gNB sends 12 beams, beam #1 1f-51 to beam #12 1f-62, and scans and sends different beams for each symbol in the OSF 1f-03. For example, when different beams are sent for each symbol in the OSF 1f-03 (e.g., beam #1 1f-51 is sent at the first symbol 1f-31), the UE can measure the OSF 1f-03 to identify the beam of the signal with the highest signal strength among the beams sent in the OSF 1f-03.

[0084] In Figure 1F , a scenario where the OSF 1f-093 is repeated every 25 subframes is assumed, and in this scenario, the remaining 24 subframes are data subframes (DSF) 1f-05 for sending and receiving general data. In addition, according to the scheduling of the base station, the third to fifth UEs 1f-75, 1f-77, and 1f-79 can communicate using beam #7 1f-11 together, the first UE 1f-71 can communicate using beam #1 1f-13, and the second UE 1f-73 can communicate using beam #5 1f-55. Although Figure 1FMainly shows transmission beams #1 1f-51 to #12 1f-62 of the base station, but reception beams of the UE for receiving the transmission beams from the base station can be additionally considered (e.g., reception beams 1f-81, 1f-83, 1f-85, 1f-87 of the first UE 1f-71). For example, referring to Figure 1F , the first UE 1f-71 may have four reception beams 1f-81, 1f-83, 1f-85, and 1f-87, and perform beam scanning to identify the beam with the best reception performance from the four reception beams 1f-81, 1f-83, 1f-85, and 1f-87. Here, when the UE cannot use multiple beams simultaneously, the UE may receive as many OSFs as the number of reception beams, one OSF for each reception beam. By receiving multiple OSFs corresponding to the multiple reception beams respectively, the UE can find the optimal pair of the transmission beam of the base station and the reception beam of the UE.

[0085] In the present disclosure, in combination with the transmission configuration indicator (TCI) state used by the base station to indicate the beam used when the UE receives resources transmitted through the physical downlink shared channel (PDSCH) in the next-generation mobile communication system, a method for improving related operations in the LTE standard specification is considered. Although according to the prior art, the UE receives the indication of the downlink beam transmitted via a single TRP, the UE may receive the indication of the downlink beam transmitted from multiple TRPs in the future NR system. However, according to the current standard specification, since there is no method for the base station to indicate the downlink beam transmitted via multiple TRPs, operations for solving this problem are needed.

[0086] Figure 1G Shows the entire process of the base station in the NR system indicating the beam for the downlink signal transmitted via the PDSCH according to an embodiment of the present disclosure.

[0087] The NR system is designed to perform data transmission and reception between the UE and the base station by using directional beams. Although data communication using directional beams can support high data rates through wide bandwidth and resources related to communication using high frequencies, it may have the limitation that the direction of the beam should be appropriately determined.

[0088] In the NR system, basically, the UE can measure the synchronization signal through the Synchronization Signal / Physical Broadcast Channel (SS / PBCH) block in the initial access phase, and can perform data transmission and reception in the beam direction where the synchronization signal is detected. The base station can configure up to 64 downlink beams for the UE via the RRC message. The downlink beams are used for the transmission of the Physical Downlink Control Channel (PDCCH), and can indicate one beam actually used among the configured downlink beams via the MAC Control Element (MAC CE). In addition, the base station performs the operations of configuring and indicating the downlink beam for the transmission of the PDSCH. Additionally, under a predetermined condition, the downlink beam used for the transmission of the PDCCH can be used instead of the downlink beam used for the transmission of the PDSCH. For example, the predetermined condition can be a case where the time required to switch the downlink beam for the PDCCH to the downlink beam for the PDSCH is shorter than the processing time required to perform the operation.

[0089] Reference Figure 1G , UE 1g-20 can receive beam configurations for beam directions 1g-06 to 1g-10 for the beam, where the Channel State Information-Reference Signal (CSI-RS) resource set 1g-15 is sent from the base station and the TRP 1g-05 connected to UE 1g-20. The beam direction configuration applies to the beam through which all transmission resources delivered through the PDSCH are sent, and the whole process is as follows.

[0090] In one example of operation 1g-25, via RRC configuration, the Transmission Configuration Indicator (TCI) state (up to 128 beams can be configured according to the LTE standard specification) is configured in the PDSCH-Config for each Bandwidth Part (BWP) of the serving cell.

[0091] In one example of operation 1g-30: The candidate beam group for activating the TCI state is indicated to the UE by using the MAC CE, where the TCI state is configured by the RRC message and corresponds to the beam through which the PDSCH is sent (up to 8 beams, that is, up to 8 TCI states can be activated according to the LTE standard specification). The purpose of the MAC CE can be to select the candidate beam that can be dynamically indicated via the Downlink Control Information (DCI) in the TCI state configured via the RRC. In addition, the MAC CE can be used to reduce the number of TCI states to be managed by the UE and the number of bits indicated in the DCI.

[0092] In one example of operation 1g-35, a specific beam among the candidate beams indicated by the MAC CE is indicated via the indicator of the DCI (consisting of 3 bits according to Rel-15).

[0093] Figure 1H It shows the entire process of a base station in an NR system indicating a beam group for a downlink signal transmitted in a PDSCH via multiple transmission reception points (TRPs) according to an embodiment of the present disclosure.

[0094] As referred to Figure 1G above, the NR system is designed to perform data transmission and reception between a UE and a base station by using directional beams. Although the process for configuring and indicating a downlink beam transmitted from a single TRP has been defined in the LTE standard specification, in a future NR system, multiple TRPs can simultaneously transmit downlink transmissions (e.g., downlink transmissions associated with the same transport block (TB)) by using beams configured for one UE. In other words, a UE can receive the configuration of two beams simultaneously at one time, and in order to receive the indication of two beams simultaneously, it may be necessary to modify the RRC configuration, MAC CE design, and DCI indication operation. Hereinafter, embodiments of the present disclosure provide a method for supporting the indication of multiple beams to a UE.

[0095] Referring to Figure 1H , UE 1h-25 can receive the beam configuration of beam directions 1h-15 to 1h-20, where CSI-RS resources and downlink resources are transmitted from the base station and multiple TRPs connected to UE 1h-25, namely the first TRP 1h-05 and the second TRP 1h-10. The beam direction configuration can cover all of the first TRP 1h-05 and the second TRP 1h-10, and the UE is capable of receiving the beam directions for one or more TRPs simultaneously.

[0096] In one example of operation 1h-30, via RRC configuration, a TCI state is configured in PDSCH-Config for each bandwidth part (BWP) of the serving cell. In this configuration, the TCI states for multiple TRPs (e.g., the first TRP 1h-05 and the second TRP 1h-10) can be provided as a list in one tci-state field. Alternatively, a separate field (e.g., tci-state-multipleTRP) can be defined for distinguishing the TCI state from the existing TCI state. The TCI state associated with multiple TRPs and the newly introduced tci-state-multipleTRP field can be set to a maximum of 128 values with reference to the LTE standard specification, and of course, can be set to 128 or more values.

[0097] Alternatively, in the RRC configuration operation, a tci-state-group field including a combination of TCI states transmitted from the first TRP 1h-05 and the second TRP 1h-10 can be defined, and the content of the tci-state-group field can be configured. For example, the tci-state-group field can be configured as {(tci-state#1),(tci-state#1,tci-state#2),(tci-state#2,tci-state#3),...,(tci-state#128)}. The maximum number of combinations in the tci-state-group field can be set to 128 or more with reference to the LTE standard specification.

[0098] In an example of operation 1h-35, the TCI state is configured by an RRC message and corresponds to the beam on which the PDSCH is transmitted by multiple TRPs, and a candidate beam group (e.g., candidate code point) for activating the TCI state (or tci-state-MultipleTRP or tci-state-group) is indicated to the UE by using a MAC CE. The purpose of the MAC CE can be to select a candidate beam group (e.g., candidate code point) that can be dynamically indicated via DCI from the beams corresponding to the TCI state (redefined TCI state, tci-state-multipleTRP or tci-state-group) configured via RRC. In addition, the MAC CE can be used to reduce the number of TCI states to be managed by the UE and the number of bits indicated in the DCI.

[0099] According to the functions defined in the previous LTE standard specification, in the prior art, the MAC CE can indicate up to eight candidate beams, and only the configuration of the beam for a single TRP is available because the DCI can indicate only one of the candidate beams. However, since there may be a case where beams for multiple TRPs are indicated, the modified MAC CE can indicate the activation of multiple beams simultaneously. The maximum number of the transmitted beam groups can be extended to eight or sixteen. That is, the candidate activation beam group can include a combination of downlink beams transmitted by using multiple TRPs or beams transmitted via a single TRP.

[0100] In an example of operation 1h-40, a specific beam group (e.g., a specific code point) in the candidate beam groups indicated by the MAC CE is indicated via an indicator in the DCI (According to the LTE standard specification, the indicator bits include 3 bits, and in the present disclosure, it may be composed of 3 or 4 bits. The number of indicator bits may be determined according to the number of beam groups indicated by the MAC CE. The beam group indicated via the DCI in operation 1h-40 means the direction of the downlink beam transmitted from multiple TRPs. In other words, the beam group indicated via the DCI in operation 1h-40 corresponds to one of the candidate beam groups indicated for activation in operation 1h-35).

[0101] In the following embodiments of the present disclosure, methods for supporting the reference Figure 1H systems described will be described, particularly the structures of the MAC CE and RRC configurations. Matters to be considered for the downlink beam indication in the multi-TRP system of Figure 1H are as follows. Hereinafter, a "code point" (or code point) may be information (or value) indicated by the MAC CE in operation 1h-35. For example, the code point may include single beam information or beam group information indicated by the MAC CE.

[0102] In an example, one or two TRPs (or TCI states) may be included in one code point (beam group indicated by the MAC CE). In other words, the downlink transmission may be a transmission from a single TRP, or may be a transmission from multiple TRPs.

[0103] In an example, the maximum number of code points activated in the MAC CE may be 8 or 16.

[0104] In an example, associated with the maximum code point, the number of DCI activation indication bits may be determined to be 3 or 4.

[0105] In an example, the newly defined MAC CE can distinguish code points. In other words, the directions of the beams transmitted simultaneously from the first TRP 1h-05 and the second TRP 1h-10 (e.g., the directions of the beams associated with the same transport block (TB)) may be configured as a beam combination in one code point.

[0106] In an example, beam indication in the multi-TRP system may be solved by separately changing the MAC CE or changing the MAC CE in association with the RRC.

[0107] In an example of an RRC change-based solution: A new field (e.g., TCI-StateMultipleTRP) is defined, and 128 code points in the new field are arranged as a list. The code points consist of up to two TCI states; and the new MAC CE uses the "V" field instead of the existing "R" field, and when the "V" field is set to 1, the MAC CE applies the newly defined TCI-StateMultipleTRP instead of the TCI-State configured via the existing RRC message.

[0108] In an example of a MAC CE change-based solution: The TCI state configured in the existing RRC is maintained. Alternatively, the structure of the TCI state configuration can be maintained, but the actually configured TCI state can be indicated considering multiple TRPs; and the new MAC CE is designed to indicate multiple beam groups simultaneously.

[0109] The method provided in the following embodiments of the present disclosure is used to apply the MAC CE defined in the LTE standard specification as the activation / deactivation of the TCI state of the UE-specific PDSCH MAC CE to multiple TRPs, which will be understood with reference to the existing MAC CE structure.

[0110] Figure 1I A MAC CE structure and a method for activating candidate downlink beam groups transmitted from multiple TRPs according to an embodiment of the present disclosure are shown.

[0111] According to an embodiment of the present disclosure, with reference to Figure 1I The provided MAC CE structure may correspond to the reused "activation / deactivation of TCI state for UE-specific PDSCH MAC CE" currently defined in the LTE standard specification. That is, Figure 1I The logical channel ID (LCID) of the shown MAC CE structure may have the same value as the previously defined LCID.

[0112] When the field 1i-05, which was previously set as the "R" field in the MAC CE structure, is set as the "V" field and the "V" field is set to 1, the MAC CE structure is defined as a MAC CE structure that supports multiple TRPs as specified in the LTE standard specification. In addition, as in the previous version of the MAC CE, the serving cell ID field 1i-10 and the BWP ID field 1i-15 are included in the MAC CE to indicate the serving cell and BWP to which the beam belongs, respectively.

[0113] The difference from the previous version of the MAC CE is that the previous version of the MAC CE indicates up to eight candidate downlink activation beams ("T" field), while in Figure 1IIn the MAC CE structure shown, the beams of TRP 1 and TRP 2 continuously form the same combination.

[0114] For example, in the existing MAC CE structure, eight "T" fields are set to 1. On the other hand, in the new MAC CE structure, sixteen "T" fields 1i - 20 corresponding to twice the number of the eight "T" fields can all be set to 1, and the first and second activation fields can form a combination of fields activated by 1 to indicate the first beam combination of TRP 1 and TRP 2. Similarly, the third and fourth activation fields can form a combination to indicate the second beam combination of TRP 1 and TRP 2. In the same way, the fifteenth and sixteenth activation fields can form a combination to indicate the eighth beam combination of TRP 1 and TRP 2.

[0115] Under the assumption that each combination of TRP 1 and TRP 2 can always be composed of two activation fields, the above MAC CE structure can be used. The MAC CE structure is also characterized in that the number of "T" fields corresponding to a multiple of 2 is always activated. Additionally, in the above MAC CE structure, as many code points as the number of the set of "T" fields divided by 2 can be set.

[0116] Figure 1J A MAC CE structure according to an embodiment of the present disclosure and a method of activating candidate downlink beam groups transmitted from multiple TRPs are shown.

[0117] Reference Figure 1J The provided MAC CE structure is similar to the MAC CE structure shown in Figure 1I in that the MAC CE structure corresponding to "TCI state activation / deactivation for UE - specific PDSCH MAC CE" currently defined in the LTE standard specification is reused. (That is, the LCID of the MAC CE structure shown in Figure 1J has the same value as the previously defined LCID). However, the MAC CE structure provided with reference to Figure 1J differs from the existing MAC CE structure in size, and the MAC CE structure provided with reference to Figure 1J differs from the MAC CE structure provided with reference to Figure 1I in that the MAC CE structure provided with reference to Figure 1J is further extended.

[0118] As Figure 1JAs shown, a new "V" field can be introduced in 1j-05 to distinguish the MAC CE format in the previous LTE standard specification from the MAC CE format in the LTE standard specification. When the "V" field is set to 1, the MAC CE structure is defined as a MAC CE structure that supports multiple TRPs as specified in the LTE standard specification. In addition, as in the previous version of the MAC CE, the serving cell ID field 1j-10 and the BWP ID field 1j-15 are included in the MAC CE structure to indicate the serving cell and the BWP to which the beam belongs, respectively.

[0119] In addition, as in the existing "T" field, the "T" field 1j-20 indicates the beam activated in TRP 1. When the number of activated "T" fields is set to N, N groups of "C" fields 1j-25 and N groups of "TCI status ID" fields 1j-30 can exist in the MAC CE structure. In addition, the combination of the "C" field 1j-25 and the "TCI status ID" field 1j-30 is sequentially mapped to the activated "T" field. For example, the first activated "T" field, the first "C" field, and the first "TCI status ID" field are mapped as a combination.

[0120] The "TCI status ID" field 1j-30 is used to indicate the beam applied to TRP 2 and can have a length of 7 bits. In other words, since the maximum number of TCI states configured via RRC is 128, the "TCI status ID" field 1j-30 can be set to 7 bits to indicate the candidate beams that can be configured in TRP 2. When the number of TCI states that can be configured via RRC increases, the size of the "TCI status ID" field 1j-30 can also increase accordingly.

[0121] The "C" field 1j-25 is an indicator that indicates whether the "TCI status ID" field 1j-30 that may exist later actually exists in the MAC CE structure. When the "C" field 1j-25 is set to 1, the "TCI status ID" field that will exist later indicates the TCI status of TRP2. When the "C" field 1j-25 is set to 0, the "TCI status ID" field that will exist later is filled with a meaningless value. In other words, the UE can ignore the "TCI status ID" field 1j-30, or the base station can set the "TCI status ID" field 1j-30 to the same ID as the ID indicating the activated TCI status of the beam from TRP 1.

[0122] Figure 1K Shows a MAC CE structure and a method for activating a candidate downlink beam group transmitted from multiple TRPs according to an embodiment of the present disclosure.

[0123] In referenceFigure 1K In the provided embodiments of the present disclosure, a new MAC CE is introduced for indicating a downlink beam group via multiple TRPs. For example, a new MAC CE structure different from the existing TCI state activation / deactivation MAC CE for PDSCH can be introduced, and a new LCID can be used. According to the reference Figure 1K In the provided embodiments, the MAC CE can be designed to have a completely new structure such that the MAC CE can be considered to have an optimal structure for indicating a downlink beam group via multiple TRPs.

[0124] Reference Figure 1K , the similarities between the new MAC CE structure and the existing MAC CE structure are that the "R" field 1k-05, the serving cell ID field 1k-10, and the BWP ID field 1k-15 indicate the serving cell and BWP to which the beam group indicated by the MAC CE belongs. In the following description, depending on the presence / absence of sub-fields, especially the "TCI code ID" field, the MAC CE 1k-01 according to the first option is distinguished from the MAC CE 1k-02 according to the second option.

[0125] First, the MAC CE 1k-01 according to the first option will be described. The subsequent field group other than the "R" field 1k-05, the serving cell ID field 1k-10, and the BWP ID field 1k-15 is capable of indicating the TCI state IDs (via the TCI state ID fields 1k-30, 1k-35, 1k-50, and 1k-55) identifying the TCI states for TRP 1 and TRP 2, and the TCI code IDs 1k-20 and 1k-40 to which the TCI code points are explicitly assigned can be provided. In addition, the "C" fields 1k-25 and 1k-45 are configured to indicate the presence of indicators of the TCI state IDs (i.e., the TCI state ID fields 1k-35 and 1k-55) corresponding to the downlink beams indicated via TRP 2.

[0126] For example, the MAC CE 1k-01 according to the first option can have the following structure: R field (1 bit) + serving cell ID (5 bits) + BWP ID (2 bits) + set {TCI code ID (3 bits) + indication of the TCI state of TRP 2 (1 bit) + TCI state of TRP 1 (7 bits) + reserved bit (1 bit) + TCI state of TRP 2 (7 bits)}.

[0127] Unlike the MAC CE 1k-01 according to the first option, the "TCI code ID" field can be omitted in the MAC CE 1k-02 according to the second option. Even if the "TCI code ID" field does not exist, the TCI state can be sequentially indicated by the MAC CE, and the UE can infer the total number of TCI codes indicated by the size of the entire MAC CE.

[0128] For example, the MAC CE 1k-02 according to the second option may have the following structure. R field (1 bit) + serving cell ID (5 bits) + BWP ID (2 bits) + set {indication of TRP 2 TCI state (1 bit) + TCI state of TRP 1 (7 bits) + reserved bit (1 bit) + TCI state of TRP 2 (7 bits)}.

[0129] In the MAC CE 1k-02, each of the TCI state IDx (x is one of 1, 2,..., N) can correspond to a code point. A code point can include the TCI state ID of TRP 1 and can additionally include the TCI state ID of TRP 2.

[0130] According to the reference Figure 1K In the provided embodiment, a new MAC CE is introduced without reusing the existing MAC CE. In this embodiment, a new LCID may be required. When the UE receives the MAC PDU, the UE checks the LCID through the sub-header information of the received MAC PDU and identifies that the received MAC CE is a new MAC CE that can be used to activate / deactivate two or more TCI states corresponding to multiple TRPs by only one PDCCH.

[0131] According to the reference Figure 1K In the provided embodiment, by introducing a "C" field in the MAC CE, it can be indicated whether there is an indication of TRP 2 for each TCI code point activated by the MAC CE. By introducing the "C" field, the MAC CE size can be flexibly adjusted, and when the TCI state indication of TRP 2 is not required, the corresponding 1-byte overhead can be reduced, thereby reducing the signaling load.

[0132] Figure 1L Shows a MAC CE structure and a method for activating candidate downlink beam groups transmitted from multiple TRPs according to an embodiment of the present disclosure.

[0133] According to the reference Figure 1LIn the embodiments of the present disclosure provided, the newly introduced MAC CE only includes parts that cannot be indicated by the above existing MAC CE when reusing the MAC CE corresponding to "activation / deactivation of TCI state for UE-specific PDSCH MAC CE" defined in the current LTE standard specification. In other words, according to the reference Figure 1L In the embodiments provided, in order to indicate the downlink beams of TRP 1 and TRP 2, the configuration information can be sent by sending the newly defined MAC CE together with the existing MAC CE.

[0134] Reference Figure 1L , the existing MAC CE structure 1l-03 includes a reserved bit 1l-05, a serving cell ID field 1l-10, a BWP ID field 1l-15, and an indicator activation TCI state bitmap "T" field 1l-20. The existing MAC CE structure 1l-03 can indicate the candidate downlink activation beams of TRP1. A new MAC CE structure for indicating the candidate downlink activation beams of TRP 2 can be defined according to two options.

[0135] First, the MAC CE 1l-01 according to the first option will be described. The MAC CE 1l-01 according to the first option can indicate the TCI state ID (via the TCI state ID fields 1l-50 and 1l-65) that identifies the TCI state for TRP 2 corresponding to TRP 1, and the TCI code ID fields 1l-40 and 1l-55 for explicitly allocating the TCI code points that map to the same TCI as TRP 1 can be provided. In addition, the "C" fields 1l-45 and 1l-60 are configured to indicate an indicator of the existence of the TCI state ID corresponding to the downlink beam indicated via TRP 2 (indicated via the TCI state ID fields 1l-50 and 1l-65). When the "C" fields 1l-45 and 1l-60 are set to 1, there are TCI state ID fields 1l-50 and 1l-65 that indicate the TCI state ID corresponding to the downlink beam indicated via TRP 2. When the "C" fields 1l-45 and 1l-60 are set to 0, there is no beam indicated by TRP 2. When the "C" fields 1l-45 and 1l-60 are set to 0, the UE can ignore the TCI state ID fields 1l-50 and 1l-65, or the base station can set the TCI state ID fields 1l-50 and 1l-65 to the same ID as the ID indicating the active TCI state of the beam from TRP 1, respectively.

[0136] The MAC CE 1l-02 according to the second option differs from the MAC structure 1l-01 according to the first option in that the MAC CE 1l-02 does not include the TCI code ID fields 1l-40 and 1l-55. The MAC CEs 1l-01 and 11-02 according to the first option and the second option may have the following structures respectively: The MAC CE 1l-01 according to the first option: R field (1 bit) + serving cell ID (5 bits) + BWP ID (2 bits) + set {TCI code ID (3 bits) + indication of the TCI state of TRP 2 (1 bit) + reserved bit (1 bit) + TCI state of TRP 2 (7 bits)}; and the MAC CE 1l-02 according to the second option: R field (1 bit) + serving cell ID (5 bits) + BWP ID (2 bits) + set {indication of the TCI state of TRP 2 (1 bit) + TCI state of TRP 2 (7 bits)}.

[0137] According to an embodiment of the present disclosure, in a newly defined MAC CE, the serving cell ID field and the BWP ID field may be omitted in a specific scenario. For example, the specific scenario may be a case where an existing MAC CE and a new MAC CE are transmitted in the same MAC PDU. Alternatively, when the serving cell ID field and the BWP ID field are omitted in the newly defined MAC CE, the MAC CE may be defined to have the same serving cell ID and BWP ID as in the previous MAC CE.

[0138] Figure 1M A method for configuring a downlink beam group via multiple TRPs and communicating with a UE performed by a BS according to an embodiment of the present disclosure is shown.

[0139] Reference Figure 1M , the UE 1m-01 in the idle mode RRC_IDLE searches for a suitable cell and camps on the gNB 1m-03 (operation 1m-05). After generating data to be transmitted, etc., the UE 1m-01 performs a connection to the gNB (operation 1m-10). While in the idle mode, the UE is not connected to the network to save power, etc., so the UE cannot transmit data. The UE needs to switch from the idle mode to the connected mode RRC_CONNECTED to transmit data. When the UE camps on a cell, the UE stays in the cell and receives paging messages to monitor whether data is arriving via the downlink. When the UE 1m-01 successfully establishes a connection to the gNB 1m-03, the UE transitions to the connected mode RRC_CONNECTED. The UE 1m-01 in the connected mode can send data to the gNB 1m-03 and receive data from the gNB 1m-03 (operation 1m-15).

[0140] When in the RRC-CONNECTED state, gNB 1m-03 sends configuration information related to the TCI state to UE 1m-01 via an RRC message (operation 1m-20). The operation of sending the RRC message also includes the operation of configuring the downlink beam for transmission via PDCCH and PDSCH through the TCI state. The downlink beam configuration is performed for each serving cell and each BWP and is included in PDCCH-Config and PDSCH-Config respectively. For example, in the LTE standard specification, gNB 1m-03 configures up to 64 downlink beams for transmission to UE 1m-01 via PDCCH via an RRC message and indicates the actually used beam among the downlink beams via a MAC CE. In addition, gNB 1m-03 performs the operations of configuring and indicating the downlink beam for transmission via PDSCH. In addition, under a predetermined condition, the downlink beam used for transmission via PDCCH can be used instead of the downlink beam used for transmission via PDSCH. For example, the predetermined condition may be a case where the processing time taken to switch the downlink beam for PDCCH to the downlink beam for PDSCH is shorter than the processing time required to perform the switching operation.

[0141] According to an embodiment of the present disclosure, even when the downlink beam is indicated via multiple TRPs, the TCI state transmitted from multiple TRPs to each serving cell and each BWP via PDSCH can be configured in a manner similar to that described in operation 1m-20. As described above, the TCI state can be configured by reusing the TCI state field included in the existing RRC control information or by introducing a new separate field. In addition, the maximum number of configurable TCI states can be 128 or more (e.g., 256). When the TCI state field is set, the actual TCI state value set in the TCI state field can indicate the beams of TRP 1 and TRP 2. Before sending the RRC message for configuring the TCI state to UE 1m-01, gNB 1m-03 can request UE capabilities and receive a UE capability report from UE 1m-01, and analyze the TRP capabilities of the gNB, the UE capabilities regarding processing downlink beams via multiple TRPs, etc., to determine which TRP beam information will be included in the TCI state based on the analysis results.

[0142] gNB 1m-03 can activate multiple beams or beam groups that can be activated according to the position and status of UE 1m-01 in the TCI state value set via RRC configuration information (operation 1m-25). As described in the foregoing operation, gNB 1m-03 can determine which version of the MAC CE will be activated by UE 1m-01. gNB 1m-03 can indicate the activation of candidate beams of a single TRP and candidate beam groups of multiple TRPs.

[0143] gNB 1m-03 indicates, via an indicator in the DCI, one code point (operation 1m-30) among the code points of the multiple downlink beam groups (code points) indicated for activation in operation 1m-25.

[0144] UE 1m-01 performs downlink data reception using the beam configured for communication with gNB 1m-03 (operation 1m-35).

[0145] gNB 1m-03 may retransmit the MAC CE for the purpose of updating the previously delivered MAC CE, and may update the beam groups that are respectively activated and deactivated (operation 1m-40).

[0146] gNB 1m-03 may indicate one of the beam groups activated in operation 1m-40, and indicate to UE 1m-01 to use one of the beam groups as the downlink beam group (operation 1m-45).

[0147] Figure 1N A flowchart of a UE according to an embodiment of the present disclosure is shown.

[0148] Reference Figure 1N , the UE performs an RRC connection procedure with the gNB and transitions to the RRC connected state (operation 1n-05). The UE receives configuration information of the TCI state ("TCI state configuration information") from the gNB via an RRCReconfiguration message (operation 1n-10). The TCI state configuration information may include beam configuration information received via the PDCCH and beam configuration information received via the PDSCH. In addition, before receiving the TCI state configuration information, the UE may report UE capabilities to the gNB.

[0149] The TCI state configuration information refers to the downlink beam configuration information of the UE. The TCI state configuration information may include beam group configuration information about multiple TRPs. For example, when the UE reports information indicating that the UE supports beam group configuration of multiple TRPs while reporting UE capabilities, the TCI state configuration information may include beam group configuration information about the TRPs.

[0150] The UE may receive from the gNB a MAC CE indicating PDSCH beam group activation for multiple TRPs (operation 1n-15). The MAC CE may have a reference Figure 1I 、 Figure 1J 、 Figure 1K or Figure 1L described structure.

[0151] The UE may identify the type of the received MAC CE to determine whether the MAC CE is a beam activation indication for a single TRP or a beam activation indication for multiple TRPs, and then perform different operations according to the determination result (operation 1n-20). For example, the UE may determine the type of the MAC CE by checking the LCID value or a specific indicator (e.g., the "V" field) in the MAC CE.

[0152] When the received MAC CE is a beam activation MAC CE for a single TRP (e.g., the MAC CE of the existing LTE standard specification), the UE may store the activation candidate beams (TCI states) applied to the single TRP (operation 1n-25). The UE may receive from the gNB a DCI including an indication of the actually used TCI state value (operation 1n-30). The UE may perform downlink data reception and CSI reporting by using the indicated downlink beam (operation 1n-35).

[0153] When the MAC CE received by the UE in operation 1n-20 is a beam activation MAC CE for multiple TRPs (e.g., a newly defined MAC CE), the UE may store the activation candidate beam group (TCI code points) applied to the multiple TRPs (operation 1n-40). The UE may receive from the gNB a DCI including an indication of the actually used TCI code point (operation 1n-45). The UE may perform downlink data reception and CSI reporting by using the indicated downlink beam group (beam configuration for TRP 1 and TRP 2) (operation 1n-50).

[0154] Figure 1O Shows a flowchart of the gNB according to an embodiment of the present disclosure.

[0155] Reference Figure 1O ,the gNB may establish an RRC connection with the UE (operation 1o-05).

[0156] The gNB may request the UE's capabilities from the UE and receive UE capability information (operation 1o-10). The gNB may determine whether the UE is capable of applying a downlink beam group configuration for multiple TRPs by analyzing the received UE capability information, and check whether the UE is capable of configuring a downlink beam group for multiple TRPs for the UE (i.e., by checking whether the configuration for multiple TRPs is feasible and whether the requirements necessary for the configuration are met).

[0157] Based on the result of checking whether it is feasible to configure transmissions using multiple TRPs for the UE, the gNB may provide TCI state configuration information to the UE via an RRC message. According to the UE capabilities and TRP support, the TCI state configuration information includes beam configurations for multiple TRPs. When the UE does not have the capability for a configuration for multiple TRPs or when the gNB determines that a configuration for multiple TRPs is not necessary, the gNB may provide TCI state configuration information including beam configurations for a single TRP to the UE instead of TCI state configuration information including beam configurations for multiple TRPs.

[0158] The gNB may send a MAC CE to the UE indicating the activation of a PDSCH beam group for multiple TRPs (operation 1o-20). The MAC CE may have a reference Figure 1I , Figure 1J , Figure 1K or Figure 1L described structure. In addition, the method for determining the beam group indicated by the MAC CE may be determined based on the UE's beam report and information such as beam information previously configured for the UE. Additionally, the gNB may always configure the beam combination of TRP 1 and TRP 2 when indicating the beam group via the MAC CE, or the gNB may activate beams from a single TRP.

[0159] The gNB may indicate via DCI one beam or beam group among the candidate activation beams or beam groups indicated by the MAC CE that will actually be used for downlink data transmission (operation 1o-25). For example, the gNB may indicate the beam or beam group to be used via a beam indicator included in the DCI.

[0160] The gNB sends downlink data to the UE in the configured beam direction (operation 1o-30).

[0161] Figure 1P Shows the internal structure of a UE according to an embodiment of the present disclosure.

[0162] Reference Figure 1P, the UE may include a radio frequency (RF) processor 1p-10, a baseband processor 1p-20, a memory 1p-30, and a controller 1p-40. The controller 1p-40 includes a multi-connection processor 1p-42. The internal structure of the UE is not limited to the above example, and the UE may include fewer or more components than Figure 1P shown in

[0163] The RF processor 1p-10 performs functions for transmitting and receiving signals via a radio channel, such as signal conversion and amplification between frequency bands. For example, the RF processor 1p-10 may up-convert a baseband signal from the baseband processor 1p-20 to an RF signal and transmit the RF signal via an antenna, and down-convert an RF signal received via the antenna to a baseband signal. For example, the RF processor 1p-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc.

[0164] The RF processor 1p-10 may also include multiple RF chains. In addition, the RF processor 1p-10 may perform beamforming. For beamforming, the RF processor 1p-10 may adjust the phase and amplitude of each signal transmitted and received through multiple antennas or antenna elements. In addition, the RF processor 1p-10 may perform MIMO operations during which multiple layers may be received. The RF processor 1p-10 may perform receive beam scanning by appropriately configuring multiple antennas or antenna elements according to the control of the controller 1p-40, or adjust the direction and width of the receive beam so that the receive beam is aligned with the transmit beam.

[0165] The baseband processor 1p-20 may perform functions for converting between a baseband signal and a bit string according to the physical layer standard of the system. For example, when transmitting data, the baseband processor 1p-20 may generate complex symbols by encoding and modulating the transmit bit string. In addition, when receiving data, the baseband processor 1p-20 may reconstruct the received bit string by demodulating and decoding the baseband signal from the RF processor 1p-10. For example, according to the OFDM scheme, when transmitting data, the baseband processor 1p-20 may generate complex symbols by encoding and modulating the transmit bit string, map the complex symbols to subcarriers, and generate OFDM symbols through an inverse fast Fourier transform (IFFT) operation and cyclic prefix (CP) insertion.

[0166] As described above, the baseband processor 1p-20 and the RF processor 1p-10 transmit and receive signals. Accordingly, the baseband processor 1p-20 and the RF processor 1p-10 may be referred to as a transmitter, a receiver, a transceiver, or a communicator. In addition, at least one of the baseband processor 1p-20 or the RF processor 1p-10 may include multiple communication modules to support different radio access technologies. Additionally, at least one of the baseband processor 1p-20 or the RF processor 1p-10 may include different communication modules to process signals in different frequency bands. For example, different radio access technologies may include wireless local area network (WLAN) technologies (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802.11), cellular network technologies (e.g., LTE), etc. Different frequency bands may include super high frequency (SHF) bands (e.g., 2.NRHz, NRHz) and millimeter (mm) wave bands (e.g., 60 GHz). The UE may transmit signals to and receive signals from the base station via the baseband processor 1p-20 and the RF processor 1p-10, and the signals may include control information and data.

[0167] The memory 1p-30 stores a basic program, an application program, and data such as configuration information for the operation of the UE. The memory 1p-30 provides the stored data in response to a request from the controller 1p-40. The memory 1p-30 may be composed of a storage medium such as a read-only memory (ROM), a random access memory (RAM), a hard disk, a compact disc (CD)-ROM, and a digital versatile disc (DVD) or a combination thereof. In addition, the memory 1p-30 may include multiple memories.

[0168] The controller 1p-40 may control all operations of the UE. For example, the controller 1p-40 may transmit and receive signals via the baseband processor 1p-20 and the RF processor 1p-10. The controller 1p-40 also writes data to and reads data from the memory 1p-30. To this end, the controller 1p-40 may include at least one processor. For example, the controller 1p-40 may include a communication processor (CP) for controlling communication and an application processor (AP) for controlling a high layer such as an application program. In addition, the controller 1p-40 may control the UE to execute a method of receiving a downlink signal by using the above-described multiple beams. In addition, at least one component in the UE may be implemented as a single chip.

[0169] Figure 1Q The configuration of a base station according to an embodiment of the present disclosure is shown.

[0170] Reference Figure 1Q, the base station may include an RF processor 1q-10, a baseband processor 1q-20, a backhaul communicator 1q-30, a memory 1q-40, and a controller 1q-50. The controller 1q-50 may include a multi-connection processor 1q-52. The internal structure of the base station is not limited to the above example, and the base station may include fewer or more components than Figure 1Q shown in

[0171] The RF processor 1q-10 performs functions for transmitting and receiving signals via a radio channel, such as signal conversion and amplification between frequency bands. For example, the RF processor 1q-10 may up-convert a baseband signal from the baseband processor 1q-20 into an RF signal and transmit the RF signal via an antenna, and down-convert an RF signal received via the antenna into a baseband signal. For example, the RF processor 1q-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. The RF processor 1q-10 may include multiple RF chains. In addition, the RF processor 1q-10 may perform beamforming. For beamforming, the RF processor 1q-10 may adjust the phase and amplitude of each signal transmitted and received through multiple antennas or antenna elements. In addition, the RF processor 1q-10 may perform MIMO operations by transmitting one or more layers.

[0172] The baseband processor 1q-20 may perform functions for converting between a baseband signal and a bit string according to the physical layer standard of a radio access technology. For example, when transmitting data, the baseband processor 1q-20 may generate complex symbols by encoding and modulating the transmitted bit string. When receiving data, the baseband processor 1q-20 may reconstruct the received bit string by demodulating and decoding the baseband signal from the RF processor 1q-10. For example, according to the OFDM scheme, when transmitting data, the baseband processor 1q-20 may generate complex symbols by encoding and modulating the transmitted bit string, map the complex symbols to subcarriers, and generate OFDM symbols through IFFT operations and CP insertion. In addition, when receiving data, the baseband processor 1q-20 may divide the baseband signal from the RF processor 1q-10 into OFDM symbols, recover the signals mapped to the subcarriers through FFT operations, and reconstruct the received bit string by demodulating and decoding. As described above, the baseband processor 1q-20 and the RF processor 1q-10 transmit and receive signals. Therefore, the baseband processor 1q-20 and the RF processor 1q-10 may be referred to as a transmitter, a receiver, a transceiver, a communicator, or a wireless communicator. The base station may send signals to and receive signals from the UE via the baseband processor 1q-20 and the RF processor 1q-10, and the signals may include control information and data.

[0173] The backhaul communicator 1q-30 can provide an interface to communicate with other nodes in the network. For example, the backhaul communicator 1q-30 can convert a bit string to be sent from the master BS to another node (such as a secondary BS and a CN) into a physical signal, and can convert a physical signal received from another node into a bit string.

[0174] The memory 1q-40 can store basic programs, application programs, and data such as configuration information for the operation of the base station. In particular, the memory 1q-40 can store information about the bearers allocated to the connected UEs, measurement results reported by the connected UEs, etc. The memory 1q-40 provides the stored data in response to a request from the controller 1q-50. The memory 1p-30 can be composed of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD or a combination thereof. In addition, the memory 1q-40 can include multiple memories.

[0175] The controller 1q-50 controls all operations of the base station. For example, the controller 1q-50 sends and receives signals through the baseband processor 1q-20 and the RF processor 1q-10 or through the backhaul communicator 1q-30. In addition, the controller 1q-50 writes data to and reads data from the memory 1q-40. To this end, the controller 1q-50 can include at least one processor. In addition, the controller 1q-50 can control the base station such that the UE can perform the method of receiving a downlink signal by using the above-mentioned multiple beams. Additionally, at least one component in the base station can be implemented as a single chip.

[0176] The method according to the embodiments of the present disclosure described in the appended claims or its specification can be implemented in hardware, software, or a combination of hardware and software.

[0177] When the method is implemented in software, a computer-readable storage medium storing at least one program (software module) can be provided. At least one program stored in the computer-readable storage medium is configured to be executed by at least one processor within the electronic device. The at least one program includes instructions that cause the electronic device to execute the method according to the embodiments of the present disclosure described in the claims or its specification.

[0178] The program (software module or software) can be stored in RAM, non-volatile memory including flash memory, ROM, electrically erasable programmable ROM (EEPROM), magnetic disk storage devices, CD-ROM, DVD, or other types of optical storage devices, and magnetic tape cartridges. Alternatively, the program can be stored in a memory that is configured as a combination of some or all of the memories. Multiple such memories can be included.

[0179] In addition, the program can be stored in an attachable storage device, which can be accessed through a communication network configured by, for example, the Internet, an intranet, a local area network (LAN), a wide LAN (WLAN), and a storage area network (SAN), or a combination thereof. The storage device can access the device that executes the method according to the embodiments of the present disclosure through an external port. In addition, a separate storage device on the communication network can also access the device that executes the method according to the embodiments of the present disclosure.

[0180] In the embodiments of the present disclosure, according to the embodiments described in the present disclosure, the components included in the present disclosure are expressed in singular or plural forms. However, for convenience, a singular or plural expression is selected to suit the presented situation, and the present disclosure is not limited to the singular or plural form. Elements expressed in plural form can be configured as a single element, or elements expressed in singular form can be configured as multiple elements.

[0181] According to an embodiment of the present disclosure, a method and an apparatus for effectively providing services in a mobile communication system are provided. In addition, according to an embodiment of the present disclosure, a method and an apparatus for transmitting and receiving signals by using multiple beams are provided.

[0182] The embodiments of the present disclosure disclosed in this specification and the drawings are only provided as specific examples to help understand the present disclosure, and do not limit the scope of the present disclosure. It is obvious to those of ordinary skill in the art that other modifications can be made without departing from the scope of the present disclosure based on the technical spirit of the present disclosure. The embodiments of the present disclosure can be combined with each other for operation when necessary. For example, the embodiments of the present disclosure can be combined with parts of other embodiments of the present disclosure to operate the BS and the UE. The embodiments of the present disclosure can be applied to other communication systems, and other modifications based on the technical spirit of the embodiments of the present disclosure can be implemented.

[0183] Although the present disclosure has been described using various embodiments, various changes and modifications can be suggested to those skilled in the art. The present disclosure is intended to cover such changes and modifications that fall within the scope of the appended claims.

Claims

1. A method performed by a user equipment (UE) in a wireless communication system, the method comprising: Receiving, from a base station (BS), physical downlink shared channel (PDSCH) configuration information including a list of transmission configuration indicator (TCI) states; Receiving, from the BS, a PDSCH medium access control element (MAC CE), the PDSCH MAC CE including information indicating activation of at least one TCI state in the list of TCI states, the PDSCH MAC CE being associated with a logical channel identifier (LCID) value; Based on the LCID value associated with the PDSCH MAC CE, identifying that the PDSCH MAC CE is a MAC CE capable of indicating two or more TCI states regarding one TCI code point; Receiving, from the BS, downlink control information (DCI) including information indicating a TCI code point; And Receiving data from the BS via the PDSCH based on the information indicating activation of at least one TCI state and the information indicating the TCI code point, Wherein the information indicating activation of at least one TCI state includes: An identifier of a first TCI state mapped to a first TCI code point, and An indicator indicating whether an identifier of a second TCI state mapped to the first TCI code point exists.

2. The method according to claim 1, wherein, In a case where the value of the indicator is 1, the information indicating activation of at least one TCI state includes an identifier of the second TCI state, and Wherein, in a case where the value of the indicator is 0, the information indicating activation of at least one TCI state does not include an identifier of the second TCI state.

3. The method according to claim 2, wherein, Receiving data from the BS via the PDSCH includes: receiving a first PDSCH transmission to which the first TCI state is applied and a second PDSCH transmission to which the second TCI state is applied, and Wherein the first PDSCH transmission and the second PDSCH transmission are associated with the same transport block (TB).

4. The method according to claim 1, wherein: The information indicating activation of at least one TCI state includes TCI state identifiers regarding up to eight TCI code points, and One or two TCI states are mapped to each TCI code point.

5. A method performed by a base station (BS) in a wireless communication system, the method comprising: Sending, to a user equipment (UE), physical downlink shared channel (PDSCH) configuration information including a list of transmission configuration indicator (TCI) states; Sending, to the UE, a PDSCH medium access control control element (MAC CE), the PDSCH MAC CE including information indicating activation of at least one TCI state in the list of TCI states, the PDSCH MAC CE being capable of indicating two or more TCI states regarding one TCI code point and being associated with a logical channel identifier (LCID) value; Sending, to the UE, downlink control information (DCI) including information indicating a TCI code point; And Sending data to the UE via the PDSCH based on the information indicating activation of at least one TCI state and the information indicating the TCI code point, Wherein the information indicating activation of at least one TCI state includes: An identifier of a first TCI state mapped to a first TCI code point, and An indicator indicating whether an identifier of a second TCI state mapped to the first TCI code point exists.

6. The method according to claim 5, wherein, In the case where the value of the indicator is 1, the information indicating the activation of at least one TCI state includes the identifier of the second TCI state, and wherein, in the case where the value of the indicator is 0, the information indicating the activation of at least one TCI state does not include the identifier of the second TCI state.

7. The method according to claim 6, wherein Sending data to the UE via the PDSCH includes: Sending a first PDSCH transmission to which the first TCI state is applied and a second PDSCH transmission to which the second TCI state is applied, and wherein, the first PDSCH transmission and the second PDSCH transmission are associated with the same transport block TB.

8. The method according to claim 5, wherein: The information indicating the activation of at least one TCI state includes TCI state identifiers for up to eight TCI code points, and One or two TCI states are mapped to each TCI code point.

9. A user equipment UE in a wireless communication system, the UE includes: A transceiver; And A processor operably connected to the transceiver, the processor being configured to: Receive physical downlink shared channel PDSCH configuration information including a list of transmission configuration indicator TCI states from a base station BS, Receive a PDSCH medium access control control element MAC CE from the BS, the PDSCH MAC CE includes information indicating the activation of at least one TCI state in the list of TCI states, and the PDSCH MAC CE is associated with a logical channel identifier LCID value, Based on the LCID value associated with the PDSCH MAC CE, identify that the PDSCH MAC CE is a MAC CE capable of indicating two or more TCI states regarding one TCI code point, Receive downlink control information DCI including information indicating a TCI code point from the BS, and Based on the information indicating the activation of the at least one TCI state and the information indicating the TCI code point, receive data from the BS via the PDSCH, wherein, the information indicating the activation of at least one TCI state includes: An identifier of a first TCI state mapped to a first TCI code point, and An indicator indicating whether an identifier of a second TCI state mapped to the first TCI code point exists.

10. A base station BS in a wireless communication system, the BS includes: A transceiver; And A processor operably connected to the transceiver, the processor being configured to: Send physical downlink shared channel PDSCH configuration information including a list of transmission configuration indicator TCI states to a user equipment UE, Send a PDSCH medium access control control element MAC CE to the UE, the PDSCH MAC CE includes information indicating the activation of at least one TCI state in the list of TCI states, and the PDSCH MAC CE is capable of indicating two or more TCI states of one TCI code point and is associated with a logical channel identifier LCID value, Transmit downlink control information (DCI) including information indicating a TCI code point to the UE, and Transmit data to the UE via PDSCH based on information indicating the activation of at least one TCI state and information indicating a TCI code point, wherein the information indicating the activation of at least one TCI state includes: an identifier of a first TCI state mapped to a first TCI code point, and an indicator indicating whether an identifier of a second TCI state mapped to the first TCI code point exists.

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