WO2022086169A1 - Method and apparatus for managing beam for cell-to-cell cooperative communication in wireless communication system - Google Patents

Abstract

The present disclosure relates to: a communication technique for merging an IoT technology with a 5G communication system for supporting a higher data transmission rate than a 4G system; and a system therefor. The present disclosure can be applied to intelligent services (for example, smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail businesses, security- and safety-related services, and the like) on the basis of a 5G communication technology and an IoT-related technology. The present disclosure discloses a method for further effectively managing a beam in a cell-to-cell cooperative communication system using a plurality of cells.

Description

Beam management method and apparatus for cooperative communication between cells in a wireless communication system

The present disclosure relates to a wireless communication system, and more particularly, to cell-to-cell cooperative communication using a plurality of cells.

Efforts are being made to develop an improved 5G communication system or pre-5G communication system in order to meet the increasing demand for wireless data traffic after commercialization of the 4G communication system. For this reason, the 5G communication system or the pre-5G communication system is called a system after the 4G network (Beyond 4G Network) communication system or the LTE system after (Post LTE). In order to achieve a high data rate, the 5G communication system is being considered for implementation in a very high frequency (mmWave) band (eg, such as a 60 gigabyte (60 GHz) band). In order to alleviate the path loss of radio waves and increase the propagation distance of radio waves in the ultra-high frequency band, in the 5G communication system, beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO) are used. ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed. In addition, for network improvement of the system, in the 5G communication system, an evolved small cell, an advanced small cell, a cloud radio access network (cloud radio access network: cloud RAN), an ultra-dense network (ultra-dense network) , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation Technology development is underway. In addition, in the 5G system, advanced coding modulation (ACM) methods such as FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), and advanced access technologies such as Filter Bank Multi Carrier (FBMC), NOMA (non orthogonal multiple access), and sparse code multiple access (SCMA) are being developed.

On the other hand, the Internet is evolving from a human-centered connection network where humans create and consume information to an Internet of Things (IoT) network that exchanges and processes information between distributed components such as objects. Internet of Everything (IoE) technology, which combines big data processing technology through connection with cloud servers, etc. with IoT technology, is also emerging. In order to implement IoT, technology elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required. , M2M), and MTC (Machine Type Communication) are being studied. In the IoT environment, an intelligent IT (Internet Technology) service that collects and analyzes data generated from connected objects and creates new values in human life can be provided. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliance, advanced medical service, etc. can be applied to

Accordingly, various attempts are being made to apply the 5G communication system to the IoT network. For example, in technologies such as sensor network, machine to machine (M2M), and MTC (Machine Type Communication), 5G communication technology is implemented by techniques such as beam forming, MIMO, and array antenna. there will be The application of cloud radio access network (cloud RAN) as the big data processing technology described above can be said to be an example of convergence of 5G technology and IoT technology.

Meanwhile, in the 5G (or NR) system, cooperative communication between cells using a plurality of cells is possible in order to increase the throughput of the terminal located at the cell boundary. Accordingly, the need for an effective beam management method in cell-to-cell cooperative communication has emerged.

In order to increase the throughput of the UE located at the cell boundary, a new type of inter-cell cooperation technology CoMP (coordinated multi-point) may be used. CoMP is a technology that reduces inter-cell interference and increases the throughput of the UE at the cell boundary by enabling neighboring cells to cooperate with each other so that not only the serving cell but also other cells can communicate with the same UE.

The present disclosure provides a plurality of transmission reception point (TRP) (hereinafter, Multiple TRP)-based CoMP (eg, NC-JT (non- We propose various techniques for coherent joint transmission). Specifically, a signaling method for instructing a PDCCH beam change or update operation of each TRP in multiple scenarios of a multi-cell group including different cells is proposed. In addition, a method of instructing a PDCCH transmission beam change or update operation of each TRP for two or more different cells (serving cell, non-serving cell) with one signaling is proposed.

According to an embodiment of the present disclosure for solving the above problems, in a method of a terminal of a wireless communication system, an inter-cell multi-transmission reception point (multi-TRP) operation ) receiving a setting message related to; receiving a control message from a node of a first cell related to the inter-cell multi-TRP operation; checking a change in a beam through which a physical downlink control channel (PDCCH) is transmitted from a node of a second cell related to the inter-cell multi-TRP operation based on the configuration message and the control message; and receiving the PDCCH from the node of the second cell through the changed beam based on the confirmation result.

In addition, according to an embodiment of the present disclosure for solving the above problems, in a method of a base station of a wireless communication system, an inter-cell multi-transmission reception point (multi-TRP) operation Transmitting a configuration message related to (operation) to the terminal; and transmitting a control message to the terminal through a node of the first cell related to the inter-cell multi-TRP operation, Physical downlink from the node of the second cell related to the inter-cell multi-TRP operation A change in a beam through which a physical downlink control channel (PDCCH) is transmitted is characterized in that it is based on configuration information included in the configuration message and control information included in the control message.

In addition, according to an embodiment of the present disclosure for solving the above problems, in a terminal of a wireless communication system, a transceiver; and controlling the transceiver to receive a configuration message related to an inter-cell multi-transmission reception point (multi-TRP) operation, and a first cell related to the inter-cell multi-TRP operation controls the transceiver to receive a control message from a node of Downlink control channel (PDCCH) includes a control unit that controls to confirm a change in the transmitted beam, and controls the transceiver to receive the PDCCH from the node of the second cell through the changed beam based on the result of the confirmation characterized in that

In addition, according to an embodiment of the present disclosure for solving the above problems, in a base station of a wireless communication system, a transceiver; and controlling the transceiver to transmit a configuration message related to an inter-cell multi-transmission reception point (multi-TRP) operation to the terminal, and a first related to the inter-cell multi-TRP operation a control unit for controlling the transceiver to transmit a control message to the terminal through a node of one cell; The change of the beam through which the control channel (PDCCH) is transmitted is characterized in that it is based on configuration information included in the configuration message and control information included in the control message.

According to an embodiment of the present disclosure, in various scenarios of a multi-cell group including different cells, the UE effectively determines the change of the PDCCH transmission beam and updates the link with the changed beam, so that the beam management is more efficient. can operate

1 is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource domain in which data or a control channel is transmitted in a wireless communication system according to an embodiment of the present disclosure.

2 is a diagram illustrating a frame, subframe, and slot structure in a 5G system.

3 is a diagram for explaining a setting of a bandwidth portion in a wireless communication system according to an embodiment of the present disclosure.

4 is a diagram illustrating a method of dynamically changing a setting for a bandwidth portion according to an embodiment of the present disclosure.

5 is a diagram for explaining a control region (Control Resource Set, CORESET) in which a downlink control channel is transmitted in a 5G system according to an embodiment of the present disclosure.

6 is a diagram illustrating a procedure for reporting UE capability according to an embodiment of the present disclosure.

7 is a diagram for explaining the configuration of a cooperative communication antenna port according to an embodiment of the present disclosure.

8A is a diagram illustrating a scenario of configuring Multi-TRP according to an embodiment of the present disclosure.

8B is a diagram illustrating a scenario of configuring Multi-TRP according to an embodiment of the present disclosure.

8C is a diagram illustrating a scenario of configuring Multi-TRP according to an embodiment of the present disclosure.

8D is a diagram illustrating a scenario of configuring Multi-TRP according to an embodiment of the present disclosure.

9 is a diagram illustrating a CORESETPoolIndex setting method of M-TRP based on Multi-DCI according to an embodiment of the present disclosure.

10 is a diagram illustrating a method of setting CORESETPoolIndex according to an embodiment of the present disclosure.

11 is a diagram illustrating a method of setting CORESETPoolIndex according to an embodiment of the present disclosure.

12 is a diagram illustrating a method of setting CORESETPoolIndex according to an embodiment of the present disclosure.

13 is a flowchart illustrating a process in which a terminal and a base station transmit and receive signals for a multi-TRP operation according to an embodiment of the present disclosure.

14A is a diagram illustrating a beam management procedure according to an embodiment.

14B is a diagram illustrating a beam management procedure according to an embodiment.

15 is a diagram illustrating a MAC CE-based beam indication method according to an embodiment of the present disclosure.

16 is a diagram illustrating a MAC CE format for MAC CE-based beam indication according to an embodiment.

17 is a flowchart illustrating an operation of instructing an intra-cell beam change according to an embodiment.

18A is a diagram illustrating a MAC CE format according to a first embodiment of the present disclosure.

18B is a diagram illustrating a MAC CE format according to a first embodiment of the present disclosure.

18C is a diagram illustrating a MAC CE format according to a first embodiment of the present disclosure.

18D is a diagram illustrating a MAC CE format according to a first embodiment of the present disclosure.

19 is a flowchart illustrating a method of instructing an inter-cell beam change according to the first embodiment of the present disclosure.

20A is a diagram illustrating a MAC CE format according to a second embodiment of the present disclosure.

20B is a diagram illustrating a MAC CE format according to a second embodiment of the present disclosure.

20C is a diagram illustrating a MAC CE format according to a second embodiment of the present disclosure.

20D is a diagram illustrating a MAC CE format according to a second embodiment of the present disclosure.

21 is a flowchart illustrating a method of simultaneously instructing to change beams of a first cell and a second cell through one control message according to a second embodiment of the present disclosure.

22 is a flowchart illustrating an operation of a terminal according to the first embodiment of the present disclosure.

23 is a flowchart illustrating an operation of a terminal according to a second embodiment of the present disclosure.

24 is a flowchart illustrating an operation of a base station according to an embodiment of the present disclosure.

25 is a diagram illustrating the structure of a terminal according to an embodiment of the present invention.

26 is a diagram illustrating a structure of a base station according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the embodiments, descriptions of technical contents that are well known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted. This is to more clearly convey the gist of the present invention without obscuring the gist of the present invention by omitting unnecessary description.

For the same reason, some components are exaggerated, omitted, or schematically illustrated in the accompanying drawings. In addition, the size of each component does not fully reflect the actual size. In each figure, the same or corresponding elements are assigned the same reference numerals.

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the embodiments of the present disclosure make the present disclosure complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present disclosure is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

At this time, it will be understood that each block of the flowchart diagrams and combinations of the flowchart diagrams may be performed by computer program instructions. These computer program instructions may be embodied in a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, such that the instructions performed by the processor of the computer or other programmable data processing equipment are not described in the flowchart block(s). It creates a means to perform functions. These computer program instructions may also be stored in a computer-usable or computer-readable memory that may direct a computer or other programmable data processing equipment to implement a function in a particular manner, and thus the computer-usable or computer-readable memory. It may also be possible for the instructions stored in the flow chart block(s) to produce an article of manufacture containing instruction means for performing the function described in the flowchart block(s). The computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to create a computer or other programmable data processing equipment. It may also be possible that instructions for performing the processing equipment provide steps for performing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative implementations it is also possible for the functions recited in blocks to occur out of order. For example, two blocks shown one after another may in fact be performed substantially simultaneously, or it may be possible that the blocks are sometimes performed in a reverse order according to a corresponding function.

At this time, the term '~ unit' used in this embodiment means software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and '~ unit' performs certain roles do. However, '-part' is not limited to software or hardware. '~' may be configured to reside on an addressable storage medium or may be configured to refresh one or more processors. Accordingly, according to some embodiments, '~ part' refers to components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, and programs. Includes procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, components and '~ units' may be implemented to play one or more CPUs in a device or secure multimedia card. Also, according to some embodiments, '~ unit' may include one or more processors.

Hereinafter, the operating principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a related well-known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification. Hereinafter, the base station is a subject that performs resource allocation of the terminal, and may be at least one of gNode B, eNode B, Node B, a base station (BS), a radio access unit, a base station controller, or a node on a network. 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 a communication function. Of course, the present disclosure is not limited to the above example. Hereinafter, a description will be given of a technique for a terminal to receive broadcast information from a base station in a wireless communication system. The present disclosure relates to a communication technique that converges a 5 ^th generation (5G) communication system for supporting a higher data rate after the 4 ^th generation (4G) system with Internet of Things (IoT) technology, and a system thereof. The present disclosure provides intelligent services (eg, smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail business, security and safety-related services, etc.) based on 5G communication technology and IoT-related technology. ) can be applied to

A term referring to broadcast information, a term referring to control information, a term related to communication coverage, a term referring to a state change (eg, an event), and network entities used in the following description Terms referring to, terms referring to messages, terms referring to components of an apparatus, and the like are exemplified for convenience of description. Accordingly, the present invention is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

For convenience of description below, some terms and names defined in 3GPP LTE (3rd generation partnership project long term evolution) standard may be used. However, the present invention is not limited by the terms and names, and may be equally applied to systems conforming to other standards.

A wireless communication system, for example, 3GPP's HSPA (High Speed Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2 HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE 802.16e, such as communication standards such as broadband wireless broadband wireless providing high-speed, high-quality packet data service It is evolving into a communication system.

As a representative example of a broadband wireless communication system, in an LTE system, an Orthogonal Frequency Division Multiplexing (OFDM) scheme is employed in Downlink (DL), and Single Carrier Frequency Division Multiple Access (SC-FDMA) is used in Uplink (UL). ) method is used. Uplink refers to a radio link in which a UE (User Equipment) or MS (Mobile Station) transmits data or control signals to a base station (eNode B, or base station (BS)). It means a wireless link that transmits data or control signals. The multiple access method as described above divides the data or control information of each user by allocating and operating the time-frequency resources for each user to transmit data or control information so that they do not overlap each other, that is, orthogonality is established. .

As a future communication system after LTE, that is, the 5G communication system must be able to freely reflect various requirements such as users and service providers, so services that satisfy various requirements must be supported. Services considered for the 5G communication system include Enhanced Mobile BroadBand (eMBB), Massive Machine Type Communication (mMTC), and Ultra Reliability Low Latency Communication (URLLC). etc.

According to some embodiments, the eMBB aims to provide a data transfer rate that is more improved than the data transfer rate supported by existing LTE, LTE-A, or LTE-Pro. For example, in the 5G communication system, the eMBB should be able to provide a maximum data rate of 20 Gbps in the downlink and a maximum data rate of 10 Gbps in the uplink from the viewpoint of one base station. At the same time, it is necessary to provide an increased user perceived data rate of the terminal. In order to satisfy such a requirement, it is required to improve transmission/reception technology, including a more advanced multi-input multi-output (MIMO) transmission technology. In addition, it is possible to satisfy the data transmission speed required by the 5G communication system by using a frequency bandwidth wider than 20 MHz in a frequency band of 3 to 6 GHz or 6 GHz or more instead of the 2 GHz band used by the current LTE.

At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in the 5G communication system. In order to efficiently provide the Internet of Things, mMTC may require large-scale terminal access support, improved terminal coverage, improved battery life, and reduced terminal cost within a cell. Since the Internet of Things is attached to various sensors and various devices to provide communication functions, it must be able to support a large number of terminals (eg, 1,000,000 terminals/km2) within a cell. In addition, since a terminal supporting mMTC is highly likely to be located in a shaded area that a cell cannot cover, such as the basement of a building, due to the nature of the service, it may require wider coverage compared to other services provided by the 5G communication system. A terminal supporting mMTC should be configured as a low-cost terminal, and since it is difficult to frequently exchange the battery of the terminal, a very long battery life time may be required.

Lastly, in the case of URLLC, as a cellular-based wireless communication service used for a specific purpose (mission-critical), remote control for a robot or machine, industrial automation, As a service used in an unmaned aerial vehicle, remote health care, emergency alert, etc., it is necessary to provide communication that provides ultra-low latency and ultra-reliability. For example, a service supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds, and at the same time has a requirement of a packet error rate of 10-5 or less. Therefore, for a service supporting URLLC, the 5G system must provide a smaller transmit time interval (TTI) than other services, and at the same time, a design requirement for allocating a wide resource in a frequency band is required. However, the aforementioned mMTC, URLLC, and eMBB are only examples of different service types, and the service types to which the present disclosure is applied are not limited to the above-described examples.

The services considered in the above-mentioned 5G communication system should be provided by convergence with each other based on one framework. That is, for efficient resource management and control, it is preferable that each service is integrated and controlled and transmitted as a single system rather than being operated independently.

In addition, although the embodiment of the present invention will be described below using LTE, LTE-A, LTE Pro, or NR system as an example, the embodiment of the present invention may be applied to other communication systems having a similar technical background or channel type. In addition, the embodiments of the present invention can be applied to other communication systems through some modifications within the scope of the present invention as judged by a person having skilled technical knowledge.

A term referring to broadcast information, a term referring to control information, a term related to communication coverage, a term referring to a state change (eg, an event), and network entities used in the following description Terms referring to, terms referring to messages, terms referring to components of an apparatus, and the like are exemplified for convenience of description. Accordingly, the present invention is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

For convenience of description below, some terms and names defined in 3GPP LTE (3rd generation partnership project long term evolution) standard may be used. However, the present invention is not limited by the terms and names, and may be equally applied to systems conforming to other standards.

1 is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource domain in which data or a control channel is transmitted in a wireless communication system.

Referring to FIG. 1 , the horizontal axis represents the time domain and the vertical axis represents the frequency domain. A basic unit of a resource in the time and frequency domain is a resource element (RE) (1-01) as 1 OFDM (orthogonal frequency division multiplexing) symbol (1-02) on the time axis and 1 subcarrier on the frequency axis It can be defined as (1-03). in the frequency domain

(for example, 12) consecutive REs may constitute one resource block (RB) 1-04.

2 is a diagram illustrating a frame, subframe, and slot structure in a 5G system.

Referring to FIG. 2 , an example of a structure of a frame 2-00, a subframe 2-01, and a slot 2-02 is illustrated in FIG. 2 . One frame (2-00) may be defined as 10 ms. One subframe (2-01) may be defined as 1 ms, and one frame (2-00) may consist of a total of 10 subframes (2-01). One slot (2-02, 2-03) may be defined as 14 OFDM symbols (that is, the number of symbols per slot (

)=14). One subframe (2-01) may consist of one or a plurality of slots (2-02, 2-03), and the number of slots (2-02, 2-03) per one subframe (2-01) may be different depending on the set value μ(2-04, 2-05) for the subcarrier spacing.

In the example of FIG. 2 , a case of μ=0 (2-04) and a case of μ=1 (2-05) are illustrated as the subcarrier spacing setting values. When μ = 0 (2-04), one subframe (2-01) may consist of one slot (2-02), and when μ = 1 (2-05), one subframe (2) -01) may be composed of two slots (2-03). That is, the number of slots per subframe (

) may vary, and accordingly, the number of slots per frame (

) may be different. According to each subcarrier spacing setting μ

and

may be defined as in [Table 1] below.

μ
0	14	10	One
One	14	20	2
2	14	40	4
3	14	80	8
4	14	160	16
5	14	320	32

In NR, one component carrier (CC) or serving cell may consist of up to 250 or more RBs. Therefore, when the terminal always receives the entire serving cell bandwidth (serving cell bandwidth) like LTE, the power consumption of the terminal may be extreme, and in order to solve this, the base station provides one or more bandwidth parts (BWP) to the terminal. It can be configured to support the UE to change the reception area within the cell.

In NR, the base station may set 'initial BWP', which is the bandwidth of CORESET #0 (or common search space, CSS), to the terminal through the MIB. Thereafter, the base station sets the initial BWP (first BWP) of the terminal through RRC signaling, and may notify at least one or more BWP configuration information that may be indicated through future downlink control information (DCI). . Thereafter, the base station may indicate which band the terminal uses by announcing the BWP ID through DCI. If the terminal does not receive DCI in the currently allocated BWP for a specific time or longer, the terminal returns to the 'default BWP' and attempts to receive DCI.

3 is a diagram for explaining a setting of a bandwidth portion in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 3 , the terminal bandwidth 3-00 may include two bandwidth portions, namely, a bandwidth portion #1(3-05) and a bandwidth portion #2(3-10). The base station may set one or more bandwidth portions to the terminal, and may set information as shown in [Table 2] below for each bandwidth portion.

Setting information 1	Bandwidth in the bandwidth portion (number of PRBs that make up the bandwidth portion)
Setting information 2	The frequency position of the bandwidth part (such information may include an offset value compared to the reference point A, and the reference point may include, for example, the center frequency of a carrier wave, a synchronization signal, a synchronization signal raster, etc.)
Setting information 3	Numerology of the bandwidth part (eg, subcarrier spacing, CP (Cyclic Prefix) length, etc.)
etc

In addition to the setting information described in [Table 2], various parameters related to the bandwidth portion may be set in the terminal. The above-described information may be transmitted by the base station to the terminal through higher layer signaling, for example, RRC signaling. At least one bandwidth part among the set one or a plurality of bandwidth parts may be activated. Whether to activate the set bandwidth portion may be semi-statically transmitted from the base station to the terminal through RRC signaling, or may be dynamically transmitted through a MAC control element (MAC CE) or DCI.

The setting of the bandwidth part supported by the above-described 5G communication system may be used for various purposes.

For example, when the bandwidth supported by the terminal is smaller than the system bandwidth, the bandwidth supported by the terminal may be supported by setting the bandwidth portion. For example, in [Table 2], the frequency position of the bandwidth part (setting information 2) is set for the terminal, so that the terminal can transmit and receive data at a specific frequency position within the system bandwidth.

As another example, for the purpose of supporting different numerologies, the base station may configure a plurality of bandwidth portions for the terminal. For example, in order to support both data transmission and reception using a subcarrier interval of 15 kHz and a subcarrier interval of 30 kHz to an arbitrary terminal, two bandwidth portions may be configured to use a subcarrier interval of 15 kHz and 30 kHz, respectively. Different bandwidth portions may be subjected to frequency division multiplexing (FDM), and when data is transmitted/received at a specific subcarrier interval, a bandwidth portion set for the corresponding subcarrier interval may be activated.

As another example, for the purpose of reducing power consumption of the terminal, the base station may configure a bandwidth portion having different sizes of bandwidths for the terminal. For example, when the terminal supports a very large bandwidth, for example, a bandwidth of 100 MHz and always transmits/receives data using the corresponding bandwidth, very large power consumption may be caused. In particular, it is very inefficient in terms of power consumption for the UE to monitor an unnecessary downlink control channel for a large bandwidth of 100 MHz in a situation in which there is no traffic. Therefore, for the purpose of reducing power consumption of the terminal, the base station may set a relatively small bandwidth portion for the terminal, for example, a bandwidth portion of 20 MHz. In the absence of traffic, the UE may perform a monitoring operation in the 20 MHz bandwidth portion, and when data is generated, it may transmit/receive data using the 100 MHz bandwidth portion according to the instruction of the base station.

4 is a diagram illustrating a method of dynamically changing a setting for a bandwidth portion according to an embodiment of the present disclosure.

Referring to FIG. 4, as described in [Table 2] above, the base station may set one or more bandwidth parts to the terminal, and as settings for each bandwidth part, the bandwidth of the bandwidth part, the frequency position of the bandwidth part, Information on the numerology of the bandwidth part may be informed to the terminal. As shown in FIG. 4 , two bandwidth portions within the terminal bandwidth 4-00, that is, bandwidth portion #1 (BPW#1, 4-05) and bandwidth portion #2 (BWP#2, 4- 10) can be set. One or a plurality of bandwidth portions may be activated among the set bandwidths, and an example in which one bandwidth portion is activated may be considered in FIG. 4 . In slot #0 (4-25), the bandwidth part #1 (4-02) is activated among the set bandwidth parts, and the terminal controls the control region #1 ( 4-45) may monitor a Physical Downlink Control Channel (PDCCH), and may transmit/receive data 4-55 in bandwidth part #1 (4-05). A control region in which the terminal receives the PDCCH may be different depending on which bandwidth portion among the configured bandwidth portions is activated, and accordingly, the bandwidth in which the terminal monitors the PDCCH may vary.

The base station may additionally transmit an indicator for changing the configuration of the bandwidth portion to the terminal. Here, changing the setting for the bandwidth portion may be considered the same as an operation of activating a specific bandwidth portion (eg, changing the activation from the bandwidth portion A to the bandwidth portion B). The base station may transmit a configuration switching indicator to the terminal in a specific slot. After receiving the configuration change indicator from the base station, the terminal may determine a bandwidth portion to be activated by applying the changed configuration according to the configuration change indicator from a specific time point. In addition, the UE may perform monitoring for the PDCCH in the control region set in the activated bandwidth portion.

In FIG. 4, the base station instructs the terminal to change the activated bandwidth part from the existing bandwidth part #1 (4-05) to the bandwidth part #2 (4-10) (Configuration Switching Indication, 4-15) can be transmitted in slot #1 (4-30). After receiving the indicator, the terminal may activate the bandwidth part #2 (6-10) according to the content of the indicator. In this case, a transition time (4-20) for changing the bandwidth portion may be required, and accordingly, a time point for changing and applying the active bandwidth portion may be determined. 4 shows a case in which a transition time 4-20 of one slot is required after receiving the setting change indicator 4-15. In the transition time (4-20), data transmission/reception may not be performed (4-60). Accordingly, the bandwidth part #2 (4-10) is activated in the slot #2 (4-35), so that the control channel and data can be transmitted/received through the corresponding bandwidth part.

The base station may preset one or more bandwidth parts to the terminal as higher layer signaling (eg, RRC signaling), and the configuration change indicator 4-15 is activated in a way that is mapped with one of the bandwidth part settings preset by the base station. can be instructed. For example, an indicator of log ₂ N bits may indicate by selecting one of N preset bandwidth parts. In [Table 3] below, an example of indicating configuration information for a bandwidth portion using a 2-bit indicator is described.

indicator value	Bandwidth Partial Settings
00	Bandwidth setting A set by upper layer signaling
01	Bandwidth setting B set with higher layer signaling
10	Bandwidth setting C set with higher layer signaling
11	Bandwidth setting D set by higher layer signaling

The configuration change indicator 4-15 for the bandwidth portion described in FIG. 4 is in the form of MAC (Medium Access Control) CE (Control Element) signaling or L1 signaling (eg, common DCI, group-common DCI, terminal-specific DCI) may be transmitted from the base station to the terminal.

According to the configuration change indicator 4-15 for the bandwidth portion described in FIG. 4 , from which point in time the bandwidth portion activation is applied may depend on the following. From which point in time the setting change is applied, it follows a predefined value (eg, it is applied from N (≥1) slots after receiving the setting change indicator), or is set from the base station to the UE through higher layer signaling (eg RRC signaling), or , may be partially included in the contents of the setting change indicator 4-15 and transmitted. Alternatively, the timing at which the setting change is applied may be determined by a combination of the above-described methods. After receiving the configuration change indicator 4-15 for the bandwidth portion, the terminal may apply the changed configuration from the point in time obtained by the above-described method.

5 is a diagram for explaining a control region (Control Resource Set, CORESET) in which a downlink control channel is transmitted in a 5G system according to an embodiment of the present disclosure.

Referring to FIG. 5 , in this embodiment, two control regions (control region #1 (5-01), control Area #2 (5-02)) can be set. The control regions 5-01 and 5-02 may be set in a specific frequency resource 5-03 within the entire terminal bandwidth portion 5-10 on the frequency axis. The control regions 5-01 and 5-02 may be set with one or more OFDM symbols on the time axis, and may be defined by a control region length (Control Resource Set Duration, 5-04). In the example of FIG. 5 , the control region #1 (5-01) is set to a control region length of two symbols, and the control region #2 (5-02) is set to a control region length of one symbol.

The control region in the 5G system described above may be set by the base station to the terminal through higher layer signaling (eg, system information, master information block (MIB), radio resource control (RRC) signaling). Setting the control region to the terminal means providing the terminal with information such as a control region identifier (Identity), a frequency position of the control region, and a symbol length of the control region. For example, information according to Table 4 may be included in the information for setting the control region to the terminal.

ControlResourceSet ::= SEQUENCE { -- Corresponds to L1 parameter 'CORESET-ID' controlResourceSetId ControlResourceSetId, (Control area identifier (Identity)) frequencyDomainResources BIT STRING (SIZE (45)), (frequency axis resource allocation information) duration INTEGER (1..maxCoReSetDuration), (Time axis resource allocation information) cce-REG-MappingType CHOICE { (CCE-to-REG mapping method) interleaved SEQUENCE { reg-BundleSize ENUMERATED {n2, n3, n6}, (REG bundle size) precoderGranularity ENUMERATED {sameAsREG-bundle, allContiguousRBs}, interleaverSize ENUMERATED {n2, n3, n6} (interleaver size) shiftIndex INTEGER(0..maxNrofPhysicalResourceBlocks-1) OPTIONAL (Interleaver Shift) }, nonInterleaved NULL }, tci-StatesPDCCH SEQUENCE(SIZE (1..maxNrofTCI-StatesPDCCH)) OF TCI-StateId OPTIONAL, (QCL setting information) tci-PresentInDCI ENUMERATED {enabled} OPTIONAL, -- Need S}

In Table 4, tci-StatesPDCCH configuration information includes one or more synchronization signal (SS)/physical broadcast channel (PBCH) blocks in a quasi co-located (QCL) relationship with a demodulation reference signal (DMRS) transmitted in the corresponding control region. (block) (referred to as an SSB or SS/PBCH block) index or CSI-RS (channel state information reference signal) index information may be included.

In a wireless communication system, one or more different antenna ports (or one or more channels, signals, and combinations thereof may be replaced) may be associated with each other by QCL configuration as shown in Table 5 below.

QCL-Info ::= SEQUENCE { cell ServCellIndex (Serving cell index to which QCL reference RS is transmitted) bwp-Id BWP-Id (bandwidth partial index over which QCL reference RS is transmitted) referenceSignal CHOICE { (indicator indicating one of CSI-RS or SS/PBCH block as QCL reference RS) csi-rs NZP-CSI-RS-ResourceId, ssb SSB-Index }, qcl-Type ENUMERATED {typeA, typeB, typeC, typeD}, (QCL type indicator) ... }

Specifically, the QCL setting can connect two different antenna ports in a relationship between a (QCL) target antenna port and a (QCL) reference antenna port, and the terminal can perform statistical characteristics (e.g., For example, all or part of the large scale parameters of the channel such as Doppler shift, Doppler spread, average delay, delay spread, average gain, spatial Rx (or Tx) parameters or the reception spatial filter coefficient or transmission spatial filter coefficient of the terminal) are set to the target antenna port. It can be applied (or assumed) upon reception.

The target antenna port means an antenna port for transmitting a channel or signal set by upper layer setting including the QCL setting, or an antenna port for transmitting a channel or signal to which a TCI state indicating the QCL setting is applied. .

The reference antenna port means an antenna port for transmitting a channel or signal indicated (specific) by a referenceSignal parameter in the QCL configuration.

Specifically, the statistical characteristics of the channel defined by the QCL setting (indicated by the parameter qcl-Type in the QCL setting) may be classified according to the QCL type as follows.

○ 'QCL-TypeA': {Doppler shift, Doppler spread, average delay, delay spread}

○ 'QCL-TypeB': {Doppler shift, Doppler spread}

○ 'QCL-TypeC': {Doppler shift, average delay}

○ 'QCL-TypeD': {Spatial Rx parameter}

In this case, the types of QCL type are not limited to the above four types, but all possible combinations are not listed in order not to obscure the gist of the description.

In the QCL-TypeA, the bandwidth and transmission period of the target antenna port are both sufficient compared to the reference antenna port (that is, the number of samples and the transmission band/time of the target antenna port in both the frequency axis and the time axis are the number of samples and transmission of the reference antenna port. More than band/time) This is a QCL type used when all statistical properties measurable in frequency and time axis can be referenced.

QCL-TypeB is a QCL type used when the bandwidth of the target antenna port is sufficient to measure measurable statistical characteristics on the frequency axis, that is, Doppler shift and Doppler spreads.

QCL-TypeC is a QCL type used when the bandwidth and transmission period of the target antenna port are insufficient to measure second-order statistics, that is, Doppler spread and delay spreads, so that only first-order statistics, that is, Doppler shift and average delay, can be referred to. .

QCL-TypeD is a QCL type set when spatial reception filter values used when receiving a reference antenna port can be used when receiving a target antenna port.

On the other hand, it is possible for the base station to set or instruct up to two QCL settings to one target antenna port through the TCI state setting as shown in Table 6 below.

TCI-State ::= SEQUENCE { tci-StateId TCI-StateId, (TCI state indicator) qcl-Type1 QCL-Info, (Set the first QCL for the target antenna port to which the TCI state is applied) qcl-Type2 QCL-Info (Set the second QCL for the target antenna port to which the TCI state is applied) OPTIONAL, -- Need R ... }

Among the two QCL settings included in one TCI state setting, the first QCL setting may be set to one of QCL-TypeA, QCL-TypeB, and QCL-TypeC. At this time, the settable QCL type is specified according to the types of the target antenna port and the reference antenna port and will be described in detail below. In addition, the second QCL setting among the two QCL settings included in the one TCI state setting may be set to QCL-TypeD, and may be omitted in some cases.

6 is a diagram illustrating a procedure for reporting UE capability according to an embodiment of the present disclosure.

In LTE and NR systems, the terminal may perform a procedure of reporting the capability supported by the terminal to the corresponding base station while connected to the serving base station. Hereinafter, this may be referred to as UE capability report.

The base station may transmit a UE capability inquiry message for requesting a capability report to the terminal in the connected state (610). The UE capability inquiry message may include a UE capability request for each RAT type. The request for each RAT type may include requested frequency band information.

In addition, the UE capability enquiry message may include a plurality of RAT types in one RRC message container. Alternatively, according to another example, a UE capability enquiry message including a request for each RAT type may be delivered to the UE multiple times. That is, the UE capability enquiry message is repeatedly transmitted a plurality of times, and the UE may configure and report a corresponding UE capability information message.

In the NR system, the base station may request UE capability for MR-DC including NR, LTE, and EN-DC. The base station may transmit a UE capability inquiry message after the terminal is connected, and may also request a UE capability report under any conditions when the base station is needed.

Upon receiving the UE capability report request from the base station, the terminal may configure or acquire UE capability according to the RAT type and band information included in the UE capability enquiry message.

Meanwhile, according to an embodiment of the present disclosure, the UE capability may include information on whether the terminal supports the multi-TRP operation. Also, the UE Capability may include information on whether the UE supports multi-TRP operation for inter-cell. Accordingly, the UE capability may be referred to as a Multi-TRP related capability.

After the UE capability is configured, the terminal may transmit a UE capability information message including the UE capability to the base station (602). The base station may then perform scheduling and transmission/reception management appropriate for the corresponding terminal based on the UE capability received from the terminal.

7 is a diagram for explaining the configuration of a cooperative communication antenna port according to an embodiment of the present disclosure.

Referring to FIG. 7 , an example of radio resource allocation for each transmission reception point (TRP) according to a joint transmission (JT) technique and a situation is illustrated.

7-00 in FIG. 7 are diagrams illustrating coherent joint transmission (C-JT) supporting coherent precoding between each cell, TRP, and/or beam. In the case of C-JT, TRP A (7-05) and TRP B (7-10) transmit the same data (PDSCH), and joint precoding can be performed in multiple TRPs. This may mean that the same DMRS ports (eg, DMRS ports A and B in both TRPs) are transmitted from TRP A (7-05) and TRP B (7-10). In this case, the terminal may receive one piece of DCI information for receiving one physical downlink shared channel (PDSCH) demodulated by the reference signal received through DMRS ports A and B.

7-20 are diagrams illustrating non-coherent joint transmission (NC-JT) supporting non-coherent precoding between each cell, TRP and/or beam am. In the case of NC-JT, different PDSCHs may be transmitted in each cell, TRP, and/or beam, and individual precoding may be applied to each PDSCH. This may mean that different DMRS ports (eg, DMRS port A in TRP A, DMRS port B in TRP B) are transmitted from TRP A (7-25) and TRP B (7-30). In this case, the UE may receive two types of DCI information for receiving PDSCH A demodulated by DMRS port A and PDSCH B demodulated by another DMRS port B.

In order to support NC-JT, which transmits data from two or more transmission points to one terminal at the same time, PDSCHs transmitted from two (or more) different transmission points are allocated through a single PDCCH, or two It is necessary to allocate PDSCHs transmitted from the above different transmission points. The UE acquires a QCL (quasi co-location) connection relationship between each reference signal or channel based on L1/L2/L3 signaling, and through this, efficiently estimates large scale parameters of each reference signal or channel can do. If the transmission point of the reference signal or channel is different, since large scale parameters are difficult to share with each other, when performing cooperative transmission, the base station simultaneously informs the terminal of quasi co-location information for two or more transmission points. It is necessary to inform through two or more TCI states.

If non-coherent cooperative transmission is supported through multiple PDCCHs, that is, when two or more PDCCHs allocate two or more PDSCHs to the same serving cell and the same bandwidth portion at the same time, two or more TCI states are each PDCCH It may be allocated to each PDSCH to DMRS ports, respectively. On the other hand, when non-coherent cooperative transmission is supported through a single PDCCH, that is, when one PDCCH allocates two or more PDSCHs to the same serving cell and the same bandwidth portion at the same time, the two or more TCI states are one It may be allocated to each PDSCH to DMRS ports through the PDCCH of .

If it is assumed that the DMRS ports allocated to the terminal at a specific time are divided into a DMRS port group A transmitted from a transmission point A and a DMRS port group B transmitted from a transmission point B, two or more TCI states are respectively connected to the DMRS port group. and a channel can be estimated based on different QCL assumptions for each group. On the other hand, different DMRS ports may be subjected to code division multiplexing (CDM), frequency division multiplexing (FDM), or time domain multiplexing (TDM) in order to increase channel measurement accuracy and reduce transmission burden at the same time. Among them, when the DMRS ports used for CDM are collectively referred to as the CDM group, code-based multiplexing works well when the channel characteristics of each port are similar to the DMRS ports in the CDM group (that is, if the channel characteristics of each port are similar, OCC (orthogonal It may be important to ensure that DMRS ports existing in the same CDM group do not have different TCI states because they are distinguished by the cover code).

Meanwhile, in the present disclosure, a node may mean a physical or logical node in a wireless communication system that transmits and receives data with a terminal through a specific cell. For example, the node may mean a transmission/reception point (hereinafter, TRP), a base station, an evolved node B (eNodeB or eNB), a next generation node B (gNodeB, or gNB), and the like. According to an embodiment, the first node may mean TRP for transmitting and receiving data to and from the terminal through the first cell, and the second node is physically separated or separated from the first node and is different from the first cell. It may mean TRP for transmitting and receiving data with the terminal through the second cell.

The operation of transmitting data through a plurality of TRPs as described above may be referred to as a multi-TRP (M-TRP) operation. In addition, an operation of transmitting data through a plurality of cells in a plurality of TRPs as described above may be referred to as an inter cell multi-TRP operation. In this case, the plurality of cells may mean each cell operated by a plurality of base stations, may mean a plurality of cells operated by one base station, or a combination thereof.

The present disclosure proposes a method for the inter cell multi TRP operation.

For the inter-cell multi-TRP (M-TRP) operation, a method for configuring the inter-cell is required. For example, an inter-cell can be configured through inter-cell configuration information, and the inter-cell configuration information includes a unit and method for configuring an inter-cell, a unit and method for grouping cells, and a method for identifying the cell. At least one of information (eg, cell id, serving cell id, physical cell id) may be included. However, the embodiment of the present disclosure is not limited thereto, and the above-described information may not be included in the inter-cell configuration information, and any information related to the inter-cell may be included. In addition to this, the inter-cell configuration information may include SSB pattern (ssb-PositionsInBurst, ssb-periodicityServingCell), sub-carrier spacing (subcarrier Spacing), frequency (absoluteFrequencySSB), and the like.

Also, in the present disclosure, the inter-cell configuration information refers to cell configuration information for inter-cell cooperative transmission, and may also be referred to as configuration information, cell configuration information, or the like. In addition, the present disclosure may be applied to inter-cell multi-TRP cooperative transmission through serving cells and inter-cell multi-TRP cooperative transmission through serving cells and non-serving cells.

8A to 8D are diagrams illustrating scenarios of configuring multi-TRP according to an embodiment of the present disclosure.

8A to 8D illustrate scenarios that can be used for cooperative communication between base stations (inter-gNB) or between cells within a base station (intra-gNB). In addition, the back-haul and front-haul of FIGS. 8A to 8D may be applied to both an ideal back-haul/front-haul and a non-ideal back-haul/front-haul. 8A to 8D may be applied between co-channels or different channels, and may also be applied to different cell IDs or the same cell ID.

8A is a diagram illustrating an example of a serving cell and PCI configuration according to a carrier aggregation (CA) operation.

Referring to FIG. 8A , the base station can set different serving cells (ServCellConfigCommon) for each cell in a CA situation in which the frequency resources occupied by each cell are different (that is, the frequency band value FrequencyInfoDL indicated by DownlinkConfigCommon in each serving cell setting is different), so you can set different indexes (ServCellIndex) for each cell and map different PCI values.

Referring to FIG. 8B, FIG. 8B illustrates an intra-cell multi-TRP operation in which one or more TRPs operate within one serving cell configuration. According to FIG. 8b, since the base station transmits the settings for channels and signals transmitted in different TRPs in one serving cell configuration, several TRPs operate based on one serving cell index (ServingCellIndex or ServCellIndex). . Accordingly, since there is one ServingCellIndex, a cell may be configured using the same physical cell Id. In this case, in order for the UE to distinguish cells, there is a need for a method of differentiating inter-cell resources in frequency-side (eg, frequency/channel/band) resources or allocating different inter-cell resources in time-side resources. However, in general, it is much more resource efficient to use all allocated resources in one CC, so a method of classifying cells in the form of cell IDs rather than classifying cells in terms of time and frequency resources may be used during cell planning.

According to an embodiment of the present disclosure, the inter-Cell for a new M-TRP is configured based on new cell ID information or the cell-related information (or may be referred to as cooperative cell configuration information, cooperative cell-related information, etc.) method can be considered. That is, according to an embodiment of the present disclosure, when a plurality of TRPs perform inter-cell cooperative transmission, a method of setting this to the UE (that is, notifying the UE that cells performing inter-cell cooperative transmission are related to other TRPs) method) is described. Meanwhile, a method of using a cell ID will be described below as an example, but the present disclosure is not limited thereto, and a method of using a physical cell ID, a serving cell index, or another identifier may also be considered.

Hereinafter, a method of configuring a cell or a cell group according to an embodiment of the present disclosure will be described. A method of setting a cell or a cell group may be configured differently according to each scenario and case.

Referring first to FIG. 8c, FIG. 8c shows an inter-cell M-TRP operation in which the CA-framework is extended.

According to Figure 8c, the base station can be configured by including settings for channels and signals transmitted in different TRPs in different serving cell settings. In other words, each TRP has an independent serving cell configuration, and the frequency band values FrequencyInfoDLs indicated by DownlinkConfigCommon in each serving cell configuration may indicate at least some overlapping bands. Since several TRPs operate based on a plurality of ServCellIndexes (ServCellIndex #1, ServCellIndex #2), it may be possible to use a separate physical cell ID (PCI) for each TRP. (one PCI assignment per ServCellIndex possible). In this case, when various SSBs are transmitted in TRP 1 and TRP 2, the SSBs have different PCI values (PCI #1 or PCI #2), and the UE can receive them separately.

Specifically, a method for setting cooperative transmission in a plurality of TRPs using cell configuration information is as follows.

Method 1: Referring to Table 7 below, a method of setting information indicating activation or deactivation of intercell multi-TRP information (IntercellForMultiTRP) in SpCell configuration information (SpCellConfig) may be considered. At this time, the following IntercellForMultiTRP information indicates activation or deactivation with 1-bit information or indicates activation when IntercellForMultiTRP information is included and deactivation when IntercellForMultiTRP information is not included. Can be set. In this way, by using ServCellIndex, it can operate based on CA framework.

Accordingly, the UE may determine that the sCell or SPCell in which the IntercellForMultiTRP is set to enable (or includes IntercellForMultiTRP) is set as the cooperating set to perform cooperative transmission.

-- Serving cell specific MAC and PHY parameters for a SpCell: SpCellConfig ::= SEQUENCE { servCellIndex ServCellIndex OPTIONAL, -- Cond SCG reconfigurationWithSync ReconfigurationWithSync OPTIONAL, -- Cond ReconfWithSync rlf-TimersAndConstants SetupRelease { RLF-TimersAndConstants } OPTIONAL, -- Need M rlmInSyncOutOfSyncThreshold ENUMERATED {n1} OPTIONAL, -- Need S spCellConfigDedicated ServingCellConfig OPTIONAL, -- Need M IntercellForMultiTRP ENUMERATED {enable, disable} OPTIONAL, -- Need M ... } Example (omitting ScellConfig)

Meanwhile, although SpCellConfig has been described as an example, the present disclosure is not limited thereto, and the same may be applied to SCell configuration information (SCellConfig).

Method 2: Meanwhile, in consideration of another embodiment, a method of configuring the IntercellForMultiTRP using ServingCellConfig as shown in Table 8 may be considered.

As described above, IntercellForMultiTRP indicates activation or deactivation with 1-bit information, or indicates activation when IntercellForMultiTRP information is included, and instructs deactivation when IntercellForMultiTRP information is not included. Accordingly, when IntercellForMultiTRP is set to enable in the ServingCellConfig (or when IntercellForMultiTRP is included in the ServingCellConfig), the UE can determine that the SCells or SPCells corresponding to the ServingCellConfig perform cooperative transmission.

ServingCellConfig ::= SEQUENCE { tdd-UL-DL-ConfigurationDedicated TDD-UL-DL-ConfigDedicated OPTIONAL, -- Cond TDD initialDownlinkBWP BWP-DownlinkDedicated OPTIONAL, -- Need M downlinkBWP-ToReleaseList SEQUENCE (SIZE (1..maxNrofBWPs)) OF BWP-Id OPTIONAL, -- Need N downlinkBWP-ToAddModList SEQUENCE (SIZE (1..maxNrofBWPs)) OF BWP-Downlink OPTIONAL, -- Need N IntercellForMultiTRP ENUMERATED {enable, disable} OPTIONAL, -- Need M

Method 3: Meanwhile, in consideration of another embodiment, cooperative cell-related information may be transmitted using higher layer signaling (RRC) for inter-cell-based multiple TRP transmission. Cooperative cell-related information may be included in CellGroupConfig as shown in Table 9 below, for example, at least one information of inter-cell group information for Multi-TRP (hereinafter, InterCellGroupForMultiTRP) and TRP group ID (hereinafter, InterCellGroupForMultiTRPGroupID). may be added to the CellGroupConfig.

However, embodiments of the present disclosure are not limited thereto. That is, the cooperative cell-related information may be configured by being included in the aforementioned SpCellConfig, SCellConfig, ServingCellConfig, and the like.

-- Configuration of one Cell-Group: CellGroupConfig ::= SEQUENCE { cellGroupId CellGroupId, rlc-BearerToAddModList SEQUENCE (SIZE(1..maxLC-ID)) OF RLC-BearerConfig rlc-BearerToReleaseList SEQUENCE (SIZE(1..maxLC-ID)) OF LogicalChannelIdentity mac-CellGroupConfig MAC-CellGroupConfig OPTIONAL, -- Need M physicalCellGroupConfig PhysicalCellGroupConfig OPTIONAL, -- Need M spCellConfig SpCellConfig OPTIONAL, -- Need M sCellToAddModList SEQUENCE (SIZE (1..maxNrofSCells)) OF sCellToReleaseList SEQUENCE (SIZE (1..maxNrofSCells)) OF SCellIndex ..., dormancySCellGroups DormancySCellGroups OPTIONAL, -- Need N InterCellGroupsForMultiTRP InterCellGroupsForMultiTRP OPTIONAL, -- Need N ... } InterCellGroupForMultiTRP-r17 ::= SEQUENCE { InterCellGroupForMultiTRPGroupID-r17 InterCellGroupForMultiTRPGroupID-r17, InterCellGroupForMultiTRPSCellList-r17 SEQUENCE (SIZE (1..maxNrofSCells)) OF SCellIndex } InterCellGroupForMultiTRPGroupID-r17 ::= INTEGER (0..5) //Create groups as many as the number of adjacent cells

For example, the InterCellGroupForMultiTRP may be included in CellGroupConfig, and the InterCellGroupForMultiTRP may be composed of InterCellGroupForMultiTRPGroupID and InterCellGroupForMultiTRPSCellList. Accordingly, SCells included in InterCellGroupForMultiTRPSCellList are grouped by InterCellGroupForMultiTRPGroupID, and the SCells or SPCells may be used for cooperative transmission.

In this case, referring to Table 7, at least one of 0 to 5 may be selected for InterCellGroupForMultiTRPGroupID. However, this is only an embodiment of the present disclosure, that is, according to the number of TRP groups, the InterCellGroupForMultiTRPGroupID may be set to a value of 5 or more.

Alternatively, InterCellGroupForMultiTRPGroupID may be included in CellGroupConfig. In this case, SCells corresponding to SCellConfig included in CellGroupConfig may have the same TRP Group ID. Therefore, a cell or cell groups having the same TRP Group ID may be used for cooperative transmission. In this way, the cooperating set of the inter-cell-based M-TR can be set by using or combining the two methods, respectively.

Method 4: Meanwhile, in consideration of another embodiment, cooperative cell-related information may be transmitted using higher layer signaling (RRC) for inter-cell-based Multiple TRP transmission, and a set constituting a CellGroup (physical ID) #X, physical Id #Y) or (servicellId #X, servicellId #Y) can be defined in a list or table form.

That is, in the present disclosure, a set of physical cell IDs or a set of servingcellIDs may be configured in CellGroup, and the set may be used for cooperative transmission. In this case, the set of the physical cell ID or the set of servingcellID may be configured through SpCellConfig, SCellConfig, ServingCellConfig, etc. in addition to CellGroupConfig.

Meanwhile, FIG. 8D shows an inter-cell M-TRP operation based on a non-CA framework.

Referring to FIG. 8D , settings for channels and signals transmitted in different TRPs may be included in one serving cell configuration. At this time, if different TRPs have different PCIs and are set to have different PCIs without a separate serving cell index setting, the UE may determine that the Inter-Cell M-TRP operation is performed.

According to the non-CA framework, a separate serving cell index (eg, ServCellIndex) may not be set for the non-serving cell. I need a way to configure PCI. Therefore, the following describes a method of configuring the PCI of the TRP for transmitting and receiving a signal to the base station through a non-serving cell to the terminal. Through this, the UE can check whether the inter-cell M-TRP is configured.

Method 1: The method of setting the SSB based on the additional PCI as the QCL reference antenna port by adding a parameter that can connect additional PCI values other than the first PCI value mapped to the existing ServCellIndex to the TCI setting or QCL setting will be used can

Specifically, as shown in Table 10 below, parameters for referring to other PCIs in addition to the PCI allocated to the corresponding serving cell may be added to the QCL setting.

QCL-Info ::= SEQUENCE { cell ServCellIndex (Serving cell index to which QCL reference RS is transmitted) bwp-Id BWP-Id (bandwidth partial index over which QCL reference RS is transmitted) referenceSignal CHOICE { (indicator indicating one of CSI-RS or SS/PBCH block as QCL reference RS) csi-rs NZP-CSI-RS-ResourceId, ssb SSB-Index }, qcl-Type ENUMERATED {typeA, typeB, typeC, typeD}, (QCL type indicator) physCellId PhysCellId ... }

Second method: Alternatively, as shown in Table 11 below, a parameter for referring to PCI other than the PCI allocated to the corresponding serving cell may be added to the TCI setting.

TCI-State ::= SEQUENCE { tci-StateId TCI-StateId, (TCI state indicator) qcl-Type1 QCL-Info, (Set the first QCL for the target antenna port to which the TCI state is applied) qcl-Type2 QCL-Info (Set the second QCL for the target antenna port to which the TCI state is applied) OPTIONAL, -- Need R physCellId PhysCellId ... }

Third method: Alternatively, if you want to map different PCI values to the first QCL setting (qcl-Type1) and the second QCL setting (qcl-Type2) in the TCI setting, two PCI (physCellId1, It is also possible to add physCellId2) to the TCI configuration.

TCI-State ::= SEQUENCE { tci-StateId TCI-StateId, (TCI state indicator) qcl-Type1 QCL-Info, (Set the first QCL for the target antenna port to which the TCI state is applied) qcl-Type2 QCL-Info (Set the second QCL for the target antenna port to which the TCI state is applied) OPTIONAL, -- Need R physCellId1 PhysCellId physCellId2 PhysCellId ... }

In allocating an additional PCI value in the QCL configuration or TCI configuration, it is possible to consider specific restrictions in consideration of the mobility configuration (or handover configuration) values of the UE.

It is possible for the base station to use a black cell list or a white cell list in the measurement configuration (eg, MeasConfig or MeasObject configuration). According to Table 13 below, the base station can set a list of PCI values connected to the black list (blackCellsToAddModList) and white list (whiteCellsToAddModList) of the PCI values that the terminal considers when measuring the SSB through MeasObject configuration.

MeasObjectNR ::= SEQUENCE { ssbFrequency ARFCN-ValueNR OPTIONAL, -- Cond SSBorAssociatedSSB ssbSubcarrierSpacing SubcarrierSpacing OPTIONAL, -- Cond SSBorAssociatedSSB smtc1 SSB-MTC OPTIONAL, -- Cond SSBorAssociatedSSB smtc2 SSB-MTC2 OPTIONAL, -- Cond IntraFreqConnected refFreqCSI-RS ARFCN-ValueNR OPTIONAL, -- Cond CSI-RS referenceSignalConfig ReferenceSignalConfig, absThreshSS-BlocksConsolidation ThresholdNR OPTIONAL, -- Need R absThreshCSI-RS-Consolidation ThresholdNR OPTIONAL, -- Need R nrofSS-BlocksToAverage INTEGER (2..maxNrofSS-BlocksToAverage) OPTIONAL, -- Need R nrofCSI-RS-ResourcesToAverage INTEGER (2..maxNrofCSI-RS-ResourcesToAverage) OPTIONAL, -- Need R quantityConfigIndex INTEGER(1..maxNrofQuantityConfig), offsetMO Q-OffsetRangeList, cellsToRemoveList PCI-List OPTIONAL, -- Need N cellsToAddModList CellsToAddModList OPTIONAL, -- Need N blackCellsToRemoveList PCI-RangeIndexList OPTIONAL, -- Need N blackCellsToAddModList SEQUENCE (SIZE (1..maxNrofPCI-Ranges)) OF PCI-RangeElement OPTIONAL, -- Need N whiteCellsToRemoveList PCI-RangeIndexList OPTIONAL, -- Need N whiteCellsToAddModList SEQUENCE (SIZE (1..maxNrofPCI-Ranges)) OF PCI-RangeElement OPTIONAL, -- Need N ... , [[ freqBandIndicatorNR-v1530 FreqBandIndicatorNR OPTIONAL, -- Need R measCycleSCell-v1530 ENUMERATED {sf160, sf256, sf320, sf512, sf640, sf1024, sf1280} OPTIONAL -- Need R ]] }

In the above example, PCI #2 is included in whiteCellsToAddModList in MeasObjectNR (or not included in blackCellsToAddModList), but PCI #3 is not included in whiteCellsToAddModList in MeasObjectNR (or included in blackCellsToAddModList), the terminal has PCI #2 You can check that it has been set. Therefore, the UE has an obligation to measure SSB for PCI #2, but has no obligation to measure SSB for PCI #3. Therefore, the UE can apply the QCL reference antenna port setting to the SSB linked to PCI #2, but may not expect the QCL reference antenna port setting to the SSB linked to PCI #3. At this time, "the terminal does not expect the QCL reference antenna port setting" means "if it is set in this way, ignore the corresponding setting" or "the terminal operation for the setting is not defined, so random processing is performed" Various applications are possible, such as "allowed to do so" or "guaranteeing that the base station does not set this setting".

Meanwhile, according to another embodiment of the present disclosure, the following method may be used for the UE to check whether the inter-cell M-TRP operation is configured in FIG. 8D .

At least one or more BWPs may be configured for TRP 1 and TRP 2, and cell-related higher layer signaling or parameters may be configured. A plurality of TRP(s) may be set so that the BWP corresponding to the inter-cell M-TRP is active among the BWPs supported by each TRP. Therefore, a plurality of BWPs may be active for M-TRP transmission. For example, for inter-cell M-TRP transmission, BWP-0 of TRP 1 is associated with CORESET 0, 1, 2, 3, 4, and BWP-1 of TRP 2 is CORESET 0, 1, 2, 3, It can be set to be associated with 4. In addition, when BWP 0 of TRP 1 and BWP 1 of TRP 2 are activated, the terminal may determine that the M-TRP operation is set. Accordingly, the terminal may perform the M-TRP operation according to the ControlResourceSet setting. That is, the terminal may transmit or receive a signal through a plurality of TRPs.

On the other hand, the above-described measurement configuration information may be used to determine whether BWP-1 of TRP 2 related to the non-serving cell is in the activation state. The freq of the band included in the measurement configuration information received from the serving cell. BWP-1 of the TPR 2 may be activated by including at least a portion of the BWP-1 in the information. For example, the measurement setting information may include frequency information (eg, ARFCN-ValueNR in freqbandindicatorNR or ssbFrequency), and when it is set to include a part of the frequency information (BWP-1) of TRP 2 in the frequency information , BWP-1 of the TRP 2 may be activated. Alternatively, the measurement configuration information may include an activated BWP or BWP ID to be used for multi-TRP inter-cell transmission, through which multi-TRP inter-cell transmission may be performed.

In addition, the measurement configuration information received from the serving cell may include information such as a measurement object (servingCellMO) and measurement Id of the serving cell. In addition, the measurement configuration information received from the serving cell may include a measurement object related to a neighboring cell. The measurement object may include at least one of information such as BWP ID and cell ID. Accordingly, the terminal may determine that BWP 0 of TRP 1 and BWP 1 of TRP 2 are activated according to the measurement object, and may perform an M-TRP operation. Alternatively, information on CellsToAddModList may be included in the measurement object, and BWP 1 of TRP 2 may be activated by including a PCI list in the information.

Alternatively, the base station transmits the BWP ID for performing multi-TRP inter-cell cooperative transmission to the terminal through configuration information such as QCL information (QCL info), or transmits the BWP ID for BWP 1 of TRP 2 to the terminal. .

Meanwhile, according to another embodiment of the present disclosure, the following method may be used for the UE to check whether the inter-cell M-TRP operation is configured in FIG. 8D .

At least one BWP may be set or activated for TRP 1 and TRP 2, and a method of newly setting the CORESET Index set in the terminal may be considered. A plurality of TRP(s) may each set one or more BWPs, where the same BWP-Id of each TRP for inter-cell M-TRP transmission may be set to be associated with a continuous (consecutive number) CORESET Index. For example, the UE may be configured such that the same BWP-Id is active from TRP 1 and TRP 2. If the maximum number of CoreSET Indexes is determined to be 5, BWP-1 of TRP 1 may be set to be associated with CORESETs 0, 1, and 2, and BWP-1 of TRP 2 may be set to be associated with CORESETs 3 and 4. For another example, if the maximum number of COREESET Index is determined to be a value of 5 or more (eg 10), then BWP-1 of TRP 1 is associated with CORESET 0-4 and BWP-1 of TRP 2 is associated with CORESET 5-9. It can be set to be

In addition, referring to Table 14 below, IntercellDownlinkBWP-Id may be added as follows to separately set the active BWP Id. Accordingly, when the BWP indicated by the IntercellDownlinkBWP-Id is activated as described above, the UE may perform the inter-cell M-TRP operation in the corresponding BWP. In case of using this method, there is an advantage of performing non-CA framework operation while maintaining the current standard in which only one BWP is active in inter-cell-based multi-TRP transmission.

ServingCellConfig ::= SEQUENCE { tdd-UL-DL-ConfigurationDedicated TDD-UL-DL-ConfigDedicated OPTIONAL, -- Cond TDD initialDownlinkBWP BWP-DownlinkDedicated OPTIONAL, -- Need M downlinkBWP-ToReleaseList SEQUENCE (SIZE (1..maxNrofBWPs)) OF BWP-Id OPTIONAL, -- Need N downlinkBWP-ToAddModList SEQUENCE (SIZE (1..maxNrofBWPs)) OF BWP-Downlink OPTIONAL, -- Need N firstActiveDownlinkBWP-Id BWP-Id IntercellDownlinkBWP-Id BWP-Id // Assign BWP Id ... }

Meanwhile, the setting and operation of CORESET monitored by the UE to perform inter-cell-based Multi-TRP transmission based on the above-described setting will be described below. In detail, for CORESET setting, new definition/change of RRC parameter CORESETPoolIndex is required.

In Rel-16, up to five CORESETs can be set within one BWP, and at this time, a set of CORESETs capable of performing multi-TRP transmission can be set to the same CORESETPoolIndex. On the other hand, it is necessary to set CORESETPoolIndex for each of a plurality of TRPs corresponding to inter-cells in Rel-17. At this time, the base station can set five or more CORESETs within one BWP, and can extend and use a plurality of existing CORESETPoolIndex for inter-cell-based multi-TRP transmission, and use new information (eg, CORESETPoolIndex-rel17 or CORESETPoolIndexForIntercell) can be used.

9 is a diagram illustrating a CORESETPoolIndex setting method of M-TRP based on Multi-DCI according to an embodiment of the present disclosure.

The UE may decode DCI by monitoring a plurality of PDCCHs included in CORESET in which CORESETPoolIndex is set to the same value in at least one BWP. In addition, the UE can expect to receive fully/partially/non-overlapped PDSCHs scheduled by the DCI.

For example, the UE may monitor CORESET #X (902) of TRP 1 and CORESET Y (903) of TRP #2 set to the same CORESETPoolIndex (901) in slot #0 (904), respectively. Accordingly, the UE may receive data in PDSCH #2 905 and PDSCH #1 906 based on the DCI received through CORESET #X and CORESET #Y.

Here, even if the PCIs set in the TRP are different from each other, the UE can determine the CORESET index(s) composed of the Multi-TRP only with the set CORESETPoolIndex. For this purpose, a specific method is described below. First, CORESETPoolIndex may be set in the UE, and the UE may perform M-TRP operation through CORESET having the same CORESETPoolIndex. For example, if CORESETPoolIndex 0 includes CORESETs 1 and 2 and CORESETPoolIndex 1 includes CORESETs 3 and 4, the UE may perform an M-TRP operation through CORESETs 1 and 2, and CORESET 3 and 4 through the M-TRP operation.

A first method for setting CORESETPoolIndex will be described. According to the first method of the present disclosure, when CORESETPoolIndex is set for the serving cell, the UE can expect that the same CORESETPoolIndex is set for the inter-cell (non-serving cell). That is, the same CORESETPoolIndex may be applied even in the inter-cell. In this case, it can be determined that the inter-cell (non-serving cell) is set implicitly without a separate CORESETPoolIndex setting.

For example, if CORESETPoolIndex 0 for the cell for TRP 1 is set to include CORESETs 1 and 2, and CORESETPoolIndex 1 is set to include CORESET 3 and 4, the UE CORESETPoolIndex 0 for the cell for TPR2 is also CORESET 1, 2 and CORESETPoolIndex 1 can be determined to include CORESETs 3 and 4.

10 is a diagram illustrating a second method of setting CORESETPoolIndex according to an embodiment of the present disclosure.

In the second method, the number of CORESETPoolIndex settings can be fixed, and the present disclosure describes a case where, for example, it is set to two. However, the embodiment of the present disclosure is not limited thereto, and the number of CORESETPoolIndex settings may be changed. The base station may set CORESETPoolIndex to 0 or 1 for each PCI. At this time, there may be two or more CORESETs included in CORESETPoolIndex 0 or 1. According to the second method, the base station may set at least one CORESET to be configured as a pool to have the same index for each PCI in order to set the CORESETPoolIndex between inter-cells. In addition, according to the second method, for TRP having the same PCI, at least two CORESETs may be included in CORESETPoolIndex, and CORESETs having the same CORESETPoolIndex may be used for inter-cell cooperative transmission.

For example, the base station may set CORESET 1 for TRP 1 and CORESET 1 for TRP 2 as inter-cell CORESETPoolIndex 0 for a specific terminal.

As another example, using the CORESETPoolIndex set in one intra-cell, the PDCCH for multi-TRP transmission may be monitored in the inter-cell using the same CORESETIndex. Specifically, referring to FIG. 10 , CORESET 1 for TRP 1 and CORESET 2 for TRP 1 may be set to CORESETPoolIndex 0 (1010) for TRP 1, and CORESET 1 for TRP 2 and CORESET 3 for TRP 2 may be set to TRP 2 CORESETPoolIndex may be set to 0 (1020). Therefore, CORESETPoolIndex 0 for TRP 1 and TRP 2 may be used for PDCCH monitoring for inter-cell multi-TRP transmission. Similarly, CORESET 3 for TRP 1, CORESET 4 for TRP 1 may be set to CORESETPoolIndex 1 (1011) for TRP 1, and CORESET 3 for TRP 2, CORESET 4 for TRP 2 may be set to CORESETPoolIndex 1 (1021) for TRP 2 can be set to Therefore, CORESETPoolIndex 1 for TRP 1 and TRP 2 may be used for PDCCH monitoring for inter-cell multi-TRP transmission. At this time, the UE may perform PDCCH monitoring for multi-TRP transmission by checking only CORESETPoolIndex regardless of PCI. In this way, the base station can set/determine so that the total number of CORESETPoolIndex is fixed and the terminal monitors all pools having the same index.

Specifically, information for setting CORESET ID and CORESETPoolIndex in the second method may be shown in Table 15 below. In this case, the case where there are two CORESETPoolIndex will be described as an example, but the number of CORESETPoolIndex may be increased, and accordingly, the number of bits of the corresponding information may also be increased. On the other hand, the UE may operate assuming that CORESETPoolIndex is 0 if there is no separate value setting in the RRC setting.

ControlResourceSet ::= SEQUENCE { controlResourceSetId ControlResourceSetId, OPTIONAL, -- Need S ... [[ coresetPoolIndex-r17 INTEGER (0..1) // fixed 2 OPTIONAL, -- Need R controlResourceSetId-r17 ControlResourceSetId-r16 OPTIONAL -- Need S ]] }

11 is a diagram illustrating a third method of setting CORESETPoolIndex according to an embodiment of the present disclosure.

In the third method, the number of CORESETPoolIndex settings can be fixed, and the present disclosure describes a case where, for example, it is set to two. However, the embodiment of the present disclosure is not limited thereto, and the number of CORESETPoolIndex settings may be changed. The base station may set CORESETPoolIndex to 0 or 1 for each PCI. In this case, there may be two or more CORESETs included in CORESETPoolIndex 0 or 1. According to the third method, the base station may set at least one CORESET to be configured as a pool to have the same index for each PCI in order to set the CORESETPoolIndex between inter-cells. Also, according to the third method, CORESETs having different PCIs may be set to be included in one CORESETPoolIndex for inter-cell cooperative transmission.

For example, the base station may set CORESET 1 for TRP 1 and CORESET 2 for TRP 2 as inter-cell CORESETPoolIndex 0 1110 for a specific terminal. In addition, the base station may set CORESET 4 for TRP 1 and CORESET 3 for TRP 2 as CORESETPoolIndex 1 (1120) between inter-cells. The terminal does not support inter-cell-based M-TRP transmission for CORESET indexes that are not set as CORESETPoolIndex (CORESET 2 for TRP 1, CORESET 3 for TRP 2, CORESET 1 for TRP 2, CORESET 4 for TRP2) in this figure. can be judged as In this way, the base station can set/determine so that the total number of CORESETPoolIndex is fixed and the terminal monitors all pools having the same index.

The CORESET setting according to the present embodiment may be configured as shown in Table 16 below. At this time, when two CORESETPoolIndex are set, the CORESETPoolIndex-r17 field may be set to ENUMERATED {n0, n1}, and when three CORESETPoolIndex is set, the CORESETPoolIndex-r17 field is set to ENUMERATED {n0, n1, n3} can be set.

Alternatively, CORESETPoolIndex may be set by dividing intra-cell and inter-cell. For example, the CORESETPoolIndex-r17 field may be set to ENUMERATED {n0, n1, n2}, and n0, n1 may be set for intra-cell and n2 may be set for inter-cell.

However, this is only an embodiment of the present disclosure and the number of CORESETPoolIndex may be changed, and accordingly, the CORESETPoolIndex-r17 field may also be set to information such as n4, n5, and the like. In addition, when CORESETPoolIndex is configured by distinguishing between intra-cell and inter-cell, information on intra-cell and information on inter-cell may be determined according to a setting of a base station or a predetermined rule.

ControlResourceSet ::= SEQUENCE { controlResourceSetId ControlResourceSetId, OPTIONAL, -- Need S ... [[ coresetPoolIndex-r17 ENUMERATED {n0, n1, n2} OPTIONAL, -- Need R controlResourceSetId-r17 ControlResourceSetId-r16 OPTIONAL -- Need S ]]

Alternatively, according to the fourth method of the present disclosure, CORESETPoolIndex may be set for intra-cell use, and CORESETPoolIndex CORESETPoolIndexFor-IntercellId (new parameter)) for inter-cell may be newly defined.

For example, CORESETPoolIndexForIntercellId may be set to include CORESETPoolIndex including the CORESET Id of each cell. CORESETPoolIndexForIntercellId 0 can be set to include CORESETPoolIndex 0 or CORESETPoolIndex 0 and CORESETPoolIndex 1 to be included. As another example, CORESETPoolIndexForIntercellId may be directly set to include the CORESET Id of each cell.

The CORESETPoolIndexForIntercellId setting may be configured as shown in Table 17 below.

ControlResourceSet ::= SEQUENCE { controlResourceSetId ControlResourceSetId, OPTIONAL, -- Need S ... [[ // coresetPoolIndex-r17 INTEGER (0..1) // 2 fixed OPTIONAL, -- Need R coresetPoolIndexForIntercellId-r17 INTEGER (0..2*maxIntercell) // N Cells controlResourceSetId-r17 ControlResourceSetId-r17 OPTIONAL -- Need S ]] }

12 is a diagram illustrating a fifth method of setting CORESETPoolIndex according to an embodiment of the present disclosure.

The fifth method describes a method of extending the number of CORESETPoolIndex settings. In this case, the base station may expand the number of pools considering the entire inter-cell by the number of PCIs. For example, it is assumed that only five CORESETs that can be included in one BWP are set, and when N PCIs are set, 2 x N CORESETPoolIndex can be set.

For example, referring to FIG. 12 , in two TRPs having two PCIs, CORESETPoolIndex 0 (1210) may include CORESET 1 for TRP 1 and CORESET 2 for TRP 1, and CORESETPoolIndex 1 (1220) is CORESET 3 for TRP 1, CORESET 3 for TRP 2 may include, CORESETPoolIndex 2 (1230) may include CORESET 4 for TRP 1, CORESET 4 for TRP 2, and CORESETPoolIndex 3 (1240) may include CORESET 1 for TRP 2, it may be set to include CORESET 2 for TRP 2. Alternatively, even if the CORESET index of TRP 2 is continuously set such as 5, 6, 7, 8, the CORESETPoolIndex mapping may be set similarly.

Accordingly, the UE may perform PDCCH monitoring for the Mult-TRP operation according to the set CORESETPoolIndex.

13 is a flowchart illustrating a process in which a terminal and a base station transmit and receive signals for a multi-TRP operation according to an embodiment of the present disclosure.

Referring to FIG. 13 , the terminal 1300 may report (transmit) the terminal capability to the base station 1310 in step S1305 . As described above, the terminal 1300 may receive the terminal capability report request from the base station 1310 and report the terminal capability accordingly. The terminal capability may include information on terminal capability for each RAT type. In addition, the terminal capability information may include information on whether the terminal supports the multi-TRP operation. In addition, the UE capability may include information on whether the terminal 1300 supports the multi-TRP operation for inter-cell.

According to an embodiment of the present disclosure, not all of the above information should be included in the terminal capability information, and some information may be omitted or other information may be added. On the other hand, if the base station 1310 has previously received or stored the terminal capability, it may not request the terminal capability report, and step S1305 may be omitted.

The base station 1310 may transmit a multi-TRP related configuration message (eg, an RRC message) to the terminal 1300 in step S1310 . The Multi-TRP related configuration information may include at least one of cell related information (or cooperative cell related information), BWP related information, and CORESETPoolIndex related information for an inter cell-based M-TRP operation. Specific details are the same as described above. Accordingly, the above-described cell setting method, BWP related method, CORESETPoolIndex setting method, etc. can be applied to this embodiment.

The terminal 1300 and the base station 1310 may perform an inter-cell multi-TRP operation in step S1315 . Specifically, the base station 1310 may indicate to the terminal 1300 that the inter-cell Multi-TRP operation is configured through the cell-related information. The terminal 1300 may confirm that the inter-cell Multi-TRP operation is configured through the cell-related information.

In addition, the terminal 1300 may receive the CORESETPoolIndex information transmitted by the base station 1310 and check information on CORESET to be monitored for a plurality of TRPs.

Accordingly, the base station 1310 may transmit DCI in the CORESET for the plurality of TRPs. The terminal 1300 may monitor the PDCCH in the CORESET for the plurality of TRPs and acquire DCI. In addition, the terminal 1300 may receive data through the PDSCH scheduled by the DCI. Also, the base station 1310 may transmit data through the PDSCH.

14A to 14B are diagrams illustrating a beam management procedure according to an embodiment.

One of the main functions in NR (or 5G) is to support a large number of controllable antenna elements for both transmit and receive. In the case of a high frequency band, a large number of antenna elements may be mainly used for beamforming for the purpose of extending coverage. All NR channels and signals, including those used for control and synchronization, are designed to support beamforming.

NR can support analog beamforming as well as digital precoding and beamforming for implementation flexibility. In a high frequency band, analog beamforming that converts a signal from digital to analog and then forms a beam may be used. In analog beamforming, a receive beam or a transmit beam may be formed in one direction at a given point in time. In addition, analog beamforming may require a process (beam sweeping) in which the same signal is repeated in a plurality of OFDM symbols but must be transmitted using different transmission beams. Since a signal can be transmitted with a high gain in any direction through the beam sweeping function, the signal can be transmitted through a narrow beam up to an intended entire coverage area.

In the case of analog reception beamforming, the base station may indicate to the terminal information for selecting a beam through which the terminal receives data and control information. Various signaling methods supporting such a beam management procedure may be considered. The beam management aims to select and maintain a combination of the direction of the transmission beam on the transmission side and the direction of the reception beam on the reception side so that the channel gain is maximized. If the beam management is efficiently operated, data rate and throughput can be maximized.

14A, the optimal beam pair may be a beam pair 1420 in which the direction of the downlink transmission beam of the base station 1410 and the direction of the downlink reception beam of the terminal 1400 directly coincide. there is. Alternatively, when a direct path between the base station 1410 and the terminal 1400 is blocked by an obstacle in the surrounding environment, the beam pair 1430 in the transmission beam direction and the reception beam direction along the reflection path may be an optimal beam pair. This can happen especially in high frequency bands where there is little diffraction at the edges of obstacles. By using the beam management function, the base station 1410 and the terminal 1400 can determine an optimal beam pair even when the above-described direct path between the transmitting side and the receiving side is blocked.

Although FIG. 14A illustrates beamforming in the downlink direction, a similar case may be assumed in the uplink direction beamforming. For example, the optimal transmission/reception beam pair in the downlink direction may be the optimal beam pair in the uplink direction as well. Similarly, the optimal beam pair in the uplink direction may be the optimal beam pair in the downlink direction as well. In this case, it may be said that beam correspondence (or beam correspondence) is established for downlink and uplink.

Meanwhile, initial beam establishment may refer to a procedure for establishing an initial beam pair. The base station may transmit a synchronization signal block (SS/PBCH block, or SSB) corresponding to each beam using different downlink beams in an initial access process. The UE may attempt random access to the BS by selecting one of a PRACH occasion (physical random access channel occasion) and a preamble corresponding to each beam. The base station may check the downlink transmission beam for the terminal based on the received random access preamble.

After the initial beam pair is established, a procedure for reconfirming the transmit beam and the receive beam by movement or rotation of the terminal may be required. Alternatively, even when the terminal is fixed, there may be a case in which a beam that has been blocked or has been blocked is received due to movement of another object in the vicinity. Therefore, a procedure for reconfirming the beam pair may be required. The procedure for reconfirming the beam pair as described above may be referred to as a beam adjustment procedure. The beam adjustment may include a downlink transmission side (eg, a base station) (downlink transmitter-side) beam adjustment and a downlink reception side (eg, a terminal) (downlink receiver-side) beam adjustment.

Referring to FIG. 14B , in the case of downlink transmission-side beam adjustment, the reception beam of the terminal 1400 may be maintained and the transmission beam of the base station 1410 may be adjusted. To this end, the base station 1410 may sequentially transmit signals using different downlink beams. In this way, the base station 1410 sequentially transmits signals using different beams may be referred to as beam sweeping.

The terminal 1400 may measure a reference signal (RS) corresponding to the different downlink beams while maintaining the reception beam 1450 . The RS may be a channel state information reference signal (CSI-RS) or an SSB. Accordingly, the terminal 1400 may measure the quality of different downlink beams on the transmission side. Also, the terminal 1400 may report different measured beam qualities to the base station 1410 . According to the above process, the optimal beam 1440 of the downlink transmission side can be identified.

Referring to FIG. 14B , in the case of downlink reception side beam adjustment, the base station 1410 maintains the downlink transmission beam 1460 and the terminal 1400 may adjust the downlink reception beam (or beam sweep). To this end, the terminal 1400 may be configured with a set of downlink RSs. The terminal 1400 may perform measurement on the RS by sequentially applying a reception beam to the configured RS. The terminal 1400 may identify the optimal beam 1470 of the downlink reception side based on the measurement value.

On the other hand, when uplink beam adjustment is required, the above-described downlink beam adjustment process may be similarly applied.

15 is a diagram illustrating a MAC CE-based beam indication method according to an embodiment of the present disclosure.

NR (or 5G) supports beam indication (or beam indication). The beam indication may mean indicating (or specifying) to the UE that the PDSCH or PDCCH is being transmitted in the same beam as the configured RS (CSI-RS or SSB). Alternatively, it may mean indicating (or specifying) that the PDSCH or PDCCH is transmitted using the same spatial filter as the configured RS. Meanwhile, in the present disclosure, transmitting or receiving the PDSCH may mean transmitting or receiving data through the PDSCH. Also, in the present disclosure, transmitting or receiving a PDCCH may mean transmitting or receiving a DCI through the PDCCH. Also, in the present disclosure, the PDCCH transmission beam may mean a transmission beam used by the base station to transmit the PDCCH to the terminal.

The beam indication may be made through downlink signaling using transmission configuration indicator state (TCI state) information. The TCI state information may include information on RS (CSI-RS or SSB). The base station may inform the terminal of beam information related to downlink transmission (PDSCH or PDCCH transmission) through the TCI state information. For example, the UE may assume that the PDSCH or PDCCH is transmitted through the same beam as the downlink transmission beam through which the RS (CSI-RS or SSB) included in the TCI state information is transmitted.

Hereinafter, a method of instructing the UE to indicate the beam through which the PDCCH is transmitted through MAC CE signaling will be described in detail.

The base station may configure N (eg, up to 128) TCI states to the terminal. The N TCI states may be included in an information element (IE) (eg, PDSCH-Config) in a configuration message (eg, RRC message) transmitted from the base station to the terminal. In addition, the base station can configure M (eg, up to 64) candidate TCI states used to indicate (or specify) a beam through which a PDCCH is transmitted, among the N, through the configuration message. Candidate TCI states used to indicate a beam through which the PDCCH is transmitted may be referred to as, for example, tci-StatesPDCCH. Some of the M candidate TCI states may be selected and included in information for configuring a control region (CORESET) related to the PDCCH, respectively. For example, each CORESET configuration information may include a list of candidate TCI states (eg, tci-StatesPDCCH-ToAddList). Each CORESET setting information may include information according to Table 4 as described above. A configuration for each TCI state in the list of candidate TCI states may be as shown in Table 18 below. The relationship between the QCL setting and the TCI state according to each TCI state setting is as described above.

-- ASN1START -- TAG-TCI-STATE-START TCI-State ::= SEQUENCE { tci-StateId TCI-StateId, qcl-Type1 QCL-Info, qcl-Type2 QCL-Info OPTIONAL, -- Need R ... } QCL-Info ::= SEQUENCE { cell ServCellIndex OPTIONAL, -- Need R bwp-Id BWP-Id OPTIONAL, -- Cond CSI-RS-Indicated referenceSignal CHOICE { csi-rs NZP-CSI-RS-ResourceId, ssb SSB-Index }, qcl-Type ENUMERATED {typeA, typeB, typeC, typeD}, ... } -- TAG-TCI-STATE-STOP -- ASN1STOP maxNrofTCI-StatesPDCCH INTEGER ::= 64 maxNrofTCI-States INTEGER ::= 128 -- Maximum number of TCI states. NZP-CSI-RS-Resource ::= SEQUENCE { nzp-CSI-RS-ResourceId NZP-CSI-RS-ResourceId, resourceMapping CSI-RS-ResourceMapping, powerControlOffset INTEGER (-8..15), powerControlOffsetSS ENUMERATED{db-3, db0, db3, db6} OPTIONAL, -- Need R scramblingID ScramblingId, periodicityAndOffset CSI-ResourcePeriodicityAndOffset OPTIONAL, -- Cond PeriodicOrSemiPersistent qcl-InfoPeriodicCSI-RS TCI-StateId OPTIONAL, -- Cond Periodic ... } -- TAG-NZP-CSI-RS-RESOURCE-STOP -- ASN1STOP

The base station transmits the configuration information to the terminal through a configuration message, and the terminal may store it. The configuration message may be a message including the above-described Multi-TRP related configuration information.

Thereafter, when there is a change in the beam through which the PDCCH is transmitted, the base station may transmit a control message (eg, MAC CE) to the terminal to indicate (or specify) the changed beam. Upon receiving the control message, the UE can confirm that the PDCCH is transmitted through the same beam as the RS (eg, CSI-RS or SSB) associated with the TCI state set for each CORESET (eg, the UE is the It can be assumed that the PDCCH is transmitted through a spatial filter such as RS). As such, indicating to the UE the beam through which the PDCCH is transmitted through the MAC CE message may be referred to as MAC CE based beam indication.

16 is a diagram illustrating a MAC CE format for MAC CE-based beam indication according to an embodiment.

The MAC CE 1610 shown in FIG. 16 may include at least one of the following fields (filed).

- Serving Cell ID: may indicate the identifier of the serving cell to which the corresponding MAC CE is applied.

- CORESET ID: may indicate the identifier of the control resource set (control resource set, CORESET) indicated by the TCI state.

- TCI state ID: may indicate the identifier of the TCI state included in the CORESET setting identified by the CORESET ID field.

The UE may receive the MAC CE 1610 and check a change in the beam through which the PDCCH is transmitted based thereon.

More specifically, the UE can confirm that the cell indicated by the Serving Cell ID field 1611 is a cell to which the MAC CE 1610 is applied. The UE can confirm that the PDCCH transmitted through the CORESET resource indicated by the CORESET ID field 1612 is transmitted through the same beam as the RS configured in association with the TCI state indicated by the TCI state ID field 1613 . Thereafter, the UE may receive the PDCCH through the changed beam.

17 is a flowchart illustrating an operation of instructing an intra-cell beam change according to an embodiment.

The serving cell (or the node for the serving cell, hereinafter the same) 1710 may transmit a control message (eg, MAC CE) to the UE 1700 in step S1705 .

In step S1710 , the terminal 1700 may confirm a change in the beam through which the PDCCH is transmitted in the serving cell 1710 .

According to an embodiment of the present disclosure, after the terminal 1700 confirms the change of the beam, the terminal 1700 checks the change-related control message (eg, MAC CE) of the beam through which the PDCCH is transmitted, and a response message thereto may be transmitted to the serving cell 1710 (not shown). In this case, the response message may be defined in MAC CE format. For example, the terminal 1700 includes a MAC subheader (subheader) including a logical channel ID (LCID) corresponding to the response message (MAC CE) and the MAC sub PDU including the response message (MAC CE) may be transmitted to the serving cell 1710 .

Alternatively, according to an embodiment of the present disclosure, the terminal 1700 may perform a subsequent operation without transmitting the above response message.

The serving cell 1710 may transmit the PDCCH to the UE 1700 through the changed beam in step S1715 . The terminal 1700 may receive the PDCCH through the changed beam.

Alternatively, in step S1715, the serving cell 1710 confirms that the control message (eg, MAC CE) has been successfully received by the terminal 1700 based on the response message, and transmits the PDCCH through the changed beam to the terminal (1700). The terminal 1700 may receive the PDCCH through the changed beam.

The method may indicate only a beam change of one serving cell. Therefore, the present disclosure proposes a method of instructing a beam change of a cell other than a serving cell (non-serving cell) in an inter-cell Multi TRP operation in the following. In addition, we propose a method of simultaneously instructing the beam change of the serving cell and the non-serving cell.

Prior to describing a method of instructing a beam change according to an embodiment of the present disclosure, as described above, a non-serving cell and a serving cell may be configured in association with each other in the RRC message. The following method may be used as a method of establishing a non-serving cell and a serving cell in connection with each other. In addition, this may be understood with reference to the methods proposed in the above-described FIGS. 8C to 8D and the description thereof.

Method 1) Unlike the CA framework setting, a Physical Cell index (PCI) can be designated for non-serving cells. The reason for configuring the PCI may be to inform the UE by classifying the TCI state setting of the non-serving cell for each PCI.

As an example, PCI (PhysCellId) may be added after the QCL type is set in QCL-Info of the RRC setting. As another example, each PCI may be added to the QCL type setting in the TCI-State of the RRC setting. As another example, in CSI-RS-CellMobility, it may be configured by adding a QCL type to the PCI configuration. Ultimately, PCI#2 can be implicitly signaled through the setting of TCI state id. In addition, in the PCI configuration, 00: PCI #2, 01: PCI#7, 10: PCI#9, 11: PCI#20 can be set through separate indexing.

Method 2) Similar to the CA framework setting, non-serving cells can be designated based on the serving cell index (ServCellIndex). Specifically, set it in the ServCellIndex format, use a separate additional index (eg, intercell Added Index 0, 1, 2, 3, 4, 5, 6, 7, 8, etc.), or group cells to create a separate ID. You can also specify

Method 3) Grouping of non-serving cells and serving cells can be indexed by setting a cell group based on PCI and serving cell index and designating a separate index for it.

Method 4) In RRC, a separate configuration may not be performed for a non-serving cell. In this case, it may not be possible to distinguish whether cells other than the Pcell configured in RRC are configured for CA purpose or operation for Multi-TRP for NC-JT purpose.

<First embodiment>

The first embodiment proposes a method of instructing a beam change of a non-serving cell in an inter-cell Multi TRP operation. In the present disclosure, a serving cell may be simply referred to as a first cell, and a TRP operating the first cell may be referred to as a first TRP. In addition, in the present disclosure, a non-serving cell may be simply referred to as a second cell, and a TRP operating the second cell may be referred to as a second TRP.

18A to 18D are diagrams illustrating a MAC CE format according to a first embodiment of the present disclosure.

Hereinafter, a method of instructing a change of a PDCCH transmission beam according to the first embodiment will be described in detail.

Example 1-1)

If a separate serving cell id is not configured in the second cell (for example, it may be the case that there is no ServCellIndex or it is assumed that it is the same as the ServCellIndex of the first cell), the base station or the terminal distinguishes the first cell from the second cell. One way to do this is to use PCI. For example, in order to change the configuration of the spatial domain of the beam through which the PDCCH is transmitted in the second TRP, the UE includes the TCI included in the RRC configuration (eg, ControlResourceSet, PDSCH-Config, NZP-CSI-RS-Resource, etc.) You can refer to -stateId. In this case, the referenced TCI-stateID is as described above in Table 18. (QCL-info: set the RS of the source for QCL setting)

As described above, in a state in which a separate serving cell ID (eg, ServCellIndex) is not configured in the second cell through the RRC configuration information, the MAC CE for indicating (or specifying) the change of the PDCCH beam is shown in FIG. 18a It may have a structure as shown in It goes without saying that the MAC CE below can be operated even if it is not set in RRC as in method 3.

Hereinafter, an embodiment using the Extended TCI state Id will be described.

The MAC CE 1810 may include a serving cell ID field 1811 , a CORESET ID field 1812 , and a TCI state ID field 1813 (when a resource created for the purpose of setting the TCI states ID is reused). Or MAC CE (1820) is Serving cell ID field (1821), CORESET Pool index field (1822) (can be omitted), CORESET ID field (1823), TCI state ID field (1824) (for inter-cell Multi TRP operation) It may include an extended (extended TCI state ID field) capable of additionally setting 128 TCI state IDs.

According to an embodiment of the present disclosure, each of the Serving Cell ID field 1811 may have a length of 5 bits, the CORESET ID field 1812 may have a length of 4 bits, and the TCI state ID field 1813 may have a length of 7 bits. Alternatively, the Serving Cell ID field 1821 may have a length of 5 bits, the CORESET Pool index field 1822 (which may be omitted) 1 bit, the CORESET ID field 1823 may have 5 bits, and the TCI state ID field 1824 may have a length of 8 bits. . However, the order of the fields and the number of bits of each field are merely examples and are not limited thereto. In addition, not all of the fields (or information) should be included in the MAC CE, and some fields may be omitted or some fields may be added.

As in the method 1 described above, since the TCI state setting for the first cell and the PCI of the second cell are already associated and set in the RRC setting process of the serving cell, in the MAC CE, the identifier of the second cell (eg PCI) It is possible to indicate the beam change or update configuration of the PDCCH while omitting .

For a specific example, the UE may refer to the RRC configuration for the cell (the first cell) indicated by the Serving Cell ID field 1811 . Through the RRC configuration, a part of the TCI state indicated by the (extended) TCI state ID fields 1813 and 1824 may be preset for the first cell and another part for the second cell. Accordingly, the UE may receive the MAC CE from the first TRP and check the PCI of the second cell by using the (extended) TCI state ID fields 1813 and 1824 of the MAC CE.

In this case, the UE transmits the PDCCH beam through the CORESET resource indicated by the CORESET ID fields 1812 and 1821 (and the CORESET Pool Index field 1822) in the second TRP, the (extended) TCI state ID field 1813 , 1824) can be confirmed that it is transmitted in the same beam as the RS configured in association with the TCI state indicated. In addition, when the CORESET Pool index field 1822 is included, the UE may confirm that the corresponding PCI is a cell configured for the purpose of inter-cell Multi TRP operation. In this case, the TCI state ID may be reflected according to the setting of QCL-info of RRC.

According to an embodiment of the present disclosure, when the UE receives a MAC CE message including one CORESET ID field (1812, 1823) and one TCI state ID (1813, 1824) field, one PDCCH transmission beam is changed. It can be interpreted as an instruction. Or, as shown below in Figure 18a, when the terminal receives a MAC CE message including a plurality of CORESET ID fields (1812, 1823) and a plurality of TCI state IDs (1813, 1824), each CORESET of the second cell It can be interpreted as that the PDCCH transmission beam for the PDCCH is updated to each TCI state (that is, transmitted through the same beam as the RS configured in association with each TCI state).

Alternatively, one CORESET ID field 1812 and 1823 and a plurality of TCI state ID fields 1813 and 1824 may be included in the MAC CE. That is, the UE may determine that a plurality of TCI states are set in one CORESET ID. For example, it may be determined that each TCI state indicated by a plurality of TCI state IDs is set to be applied to correspond to a plurality of search spaces (sets) in one CORESET.

Example 1-2)

If a separate serving cell id is not configured in the second cell (for example, it may be the case that there is no ServCellIndex or it is assumed that it is the same as the ServCellIndex of the first cell), the base station or the terminal distinguishes the first cell from the second cell. One way to do this is to use PCI. For example, in order to change the configuration of the spatial domain of the beam through which the PDCCH is transmitted in the second TRP, the UE includes the TCI included in the RRC configuration (eg, ControlResourceSet, PDSCH-Config, NZP-CSI-RS-Resource, etc.) You can refer to -stateId. In this case, the referenced TCI-stateID is as described above in Table 18. (QCL-info: set the RS of the source for QCL setting)

As described above, in a state in which a separate ServCellIndex (serving cell ID) is not configured in the second cell through the RRC configuration information, the MAC CE for instructing (or specifying) the change of the PDCCH beam is as shown in FIG. 18B . may have the same structure. It goes without saying that the MAC CE below can be operated even if it is not set in RRC as in method 3.

Hereinafter, an embodiment using PCI will be described.

The MAC CE 1830 may include a Physical Cell ID (PCI) field 1831 , a CORESET ID field 1832 , a CORESET Pool index field (optionally omitted) 1833 , and a TCI state ID field 1834 .

According to an embodiment of the present disclosure, each PCI field 1831 is 10 bits, the CORESET ID field 1832 is 5 bits (or 4 bits), the CORESET Pool index field (can be omitted) 1833 is 1 bit, the TCI state ID field ( 1834) may have a length of 7 bits. However, the order of the fields and the number of bits of each field are merely examples and are not limited thereto. In addition, not all of the fields (or information) should be included in the MAC CE, and some fields may be omitted or some fields may be added.

The UE may identify a cell (second cell) having PCI indicated by the PCI field 1831 . At this time, the UE, in the second TRP, the beam through which the PDCCH is transmitted through the CORESET resource indicated by the CORESET ID field 1832 (and the CORESET Pool Index field 1833) is the TCI indicated by the TCI state ID field 1834. It can be confirmed that it is transmitted in the same beam as the RS configured in association with the state. In this case, the TCI state ID may be reflected according to the setting of QCL-info of RRC.

Here, PCI may be a case in which PCI is not set together in TCI state ID, QCL info, etc. through an RRC message. Alternatively, it may be included when PCI has been established, but replacement of the serving cell ID is explicitly required. For example, the PCI included in the MAC CE may be one of PCI used to report uplink feedback.

In addition, when the CORESET Pool index field 1833 is included, the UE may confirm that the corresponding PCI is a cell configured for the purpose of inter-cell Multi TRP operation. In addition, the TCI state ID may be reflected according to the setting of QCL-info of RRC.

According to an embodiment of the present disclosure, when the UE receives a MAC CE message including one CORESET ID field 1832 and one TCI state ID field 1834, it is interpreted as indicating a change of one PDCCH transmission beam. can do. Alternatively, when the UE receives a MAC CE message including a plurality of CORESET ID fields 1832 and a plurality of TCI state ID fields 1834 as shown below in FIG. 18b , the PDCCH transmission beam for each CORESET of the second cell It can be interpreted as being updated to each TCI state (that is, transmitted through the same beam as RS configured in association with each TCI state).

Alternatively, one CORESET ID field 1832 and a plurality of TCI state ID fields 1834 may be included in the MAC CE. That is, the UE may determine that a plurality of TCI states are set in one CORESET ID. For example, it may be determined that each TCI state indicated by a plurality of TCI state IDs is set to be applied to correspond to a plurality of search spaces (sets) in one CORESET.

Example 1-3)

When a separate serving cell id (eg, ServCellIndex) is configured in the second cell, the Serving Cell ID field 1611 can be used as it is or partially extended to indicate a change in the beam through which the PDCCH is transmitted in the second TRP. . Since the second cell has a serving cell configuration according to an independent ServCellIndex, and one PCI can be allocated per ServCellIndex, the ServCellIndex and PCI of the second cell can be indicated through the Serving Cell ID field 1611 .

As described above, in a state in which a separate ServCellIndex (serving cell ID) is configured in the second cell through the RRC configuration information, the MAC CE for instructing (or specifying) the change of the PDCCH beam is as shown in FIG. 18C . can have a structure. Of course, it is also possible to utilize the PCI described above.

Hereinafter, an embodiment using an additional bit(s) for an inter cell will be described.

MAC CE (1840) includes a Serving Cell ID field (1841), an identifier field that additionally defines an inter cell in addition to the basic serving cell ID (eg, an Intercell field) (1842), a CORESET ID field (1843), and a CORESET Pool index field ( may be omitted) 1844 , and a TCI state ID field 1845 .

According to an embodiment of the present disclosure, each of the Serving Cell ID field 1841 is 5 bits, the Intercell field 1842 is 1 bit (1 to 4 bits), the CORESET ID field 1843 is 5 bits (or 4 bits), and the CORESET Pool index field (Can be omitted) 1844 may have a length of 1 bit, and the TCI state ID field 1844 may have a length of 7 bits. However, the order of the fields and the number of bits of each field are merely examples and are not limited thereto. In addition, not all of the fields (or information) should be included in the MAC CE, and some fields may be omitted or some fields may be added.

Here, the inter cell identifier field 1842 may be used to distinguish it from the ServCellindex used for the existing carrier aggregation (CA). For example, in the above-described RRC configuration, whether the ServCellIndex of the second cell is for CA or for inter-cell Multi TRP operation may not be distinguished. In this case, when the value of the inter cell identifier field 1842 is indicated as 1, the UE may determine that the ServCellIndex of the second cell configured in a higher layer (eg, RRC) is for inter-cell Multi TRP. In another embodiment, CA and inter-cell Multi TRP operation may be independently configured in the above-described RRC configuration. For example, in the RRC configuration, ServCellIndex for CA operation and ServCellndex for inter-cell Multi TRP operation may be separately configured. In this case, since the UE can determine for which operation the ServCellIndex of the second cell configured in a higher layer (eg, RRC) is used, in this case, the inter cell identifier field 1842 may be omitted. That is, when the ServCellIndex is set to be clearly distinguished for the purpose of carrier aggregation in the RRC configuration, the inter cell identifier field 1842 may be unnecessary, and if it is implicitly indicated without being distinguished, the inter cell identifier field 1842 may be required.

In this embodiment, the case where the inter cell identifier field 1842 is 1 bit is illustrated, but it may be extended to a plurality of bits according to the number of non-serving cells linked for the inter-cell Multi TRP operation with a specific serving cell. As another example, when the value of the inter cell identifier field 1842 is set to 0, the UE may regard the cell indicated by the serving cell ID field 1841 as the first cell.

The UE may identify the PCI of the second cell through the serving cell configuration of the cell (second cell) indicated by the Serving Cell ID field 1841 (and the inter cell identifier field 1842).

At this time, in the second TRP, the UE transmits the PDCCH beam through the CORESET resource indicated by the CORESET ID field 1843 (and the CORESET Pool Index field 1844) in the second TRP is the TCI state indicated by the TCI state ID field 1845. It can be confirmed that it is transmitted on the same beam as the RS configured in association with . In this case, the TCI state ID may be reflected according to the setting of QCL-info of RRC.

According to an embodiment of the present disclosure, when the UE receives a MAC CE message including one CORESET ID field 1843 and one TCI state ID field, it can be interpreted as indicating a change of one PDCCH transmission beam. . Alternatively, when receiving a MAC CE message including a plurality of CORESET ID fields 1843 and a plurality of TCI state IDs as shown below in FIG. 18C, the PDCCH transmission beam for each CORESET of the second cell is transferred to each TCI state. It can be interpreted as being updated (that is, transmitted through the same beam as the RS configured in association with each TCI state).

Alternatively, one CORESET ID field 1843 and a plurality of TCI state ID fields 1845 may be included in the MAC CE. That is, the UE may determine that a plurality of TCI states are set in one CORESET ID. For example, it may be determined that each TCI state indicated by a plurality of TCI state IDs is set to be applied to correspond to a plurality of search spaces (sets) in one CORESET.

Example 1-4)

When the PCI of the second cell is configured through the RRC configuration (eg, MeasConfig or MeasObject) for measurement, the PCI (PCI) of the second cell to indicate the change of the beam through which the PDCCH is transmitted in the second TRP You can use the SSB index linked to #2).

As described above, in a state in which the SSB index associated with the PCI of the second cell is set through the RRC configuration information, the MAC CE for instructing (or specifying) the change of the PDCCH beam may have a structure as shown in FIG. 18D. there is. Of course, it is also possible to utilize the PCI and serving cell ID described above. According to the MAC CE structure shown in FIG. 18D , QCL association of CORESET ID can be used for measurement or QCL assumption operation by setting QCL parameters not only CORESET ID of the corresponding serving cell ID but also SSB ID.

Hereinafter, an embodiment using the SSB ID will be described.

MAC CE (1850) may include a Serving Cell ID field (1851), a CORESET ID field (1852), a CORESET Pool index (can be omitted) (1853), a TCI state ID field (1854), and an SSB ID field (1855). there is. As another embodiment, when a separate serving cell ID is configured in the second TRP, the Serving Cell ID field 1851 may indicate the second cell, and an identifier that additionally defines an inter cell by applying the above-described embodiment. Fields can also be used.

According to an embodiment of the present disclosure, each of the Serving Cell ID field 1851 is 5 bits, the CORESET ID field 1852 is 5 bits (or 4 bits), the TCI state ID field 1854 is 7 bits, and the SSB ID field 1855 is It can have a length of 6 bits. However, the order of the fields and the number of bits of each field are merely examples and are not limited thereto. In addition, not all of the fields (or information) should be included in the MAC CE, and some fields may be omitted or some fields may be added.

When a separate serving cell ID is not configured in the second cell and the PCI of the second cell is configured through RRC configuration (eg, MeasConfig or MeasObject) for measurement, a method similar to that of Example 1-1 this can be used In other words, since the SSB index associated with the PCI of the second cell is set through the RRC setting for measurement included in the serving cell setting of the first cell, the serving cell ID or PCI of the second cell is omitted and the SSB Index It is possible to indicate the change of the beam through which the PDCCH is transmitted in the second cell.

The UE may refer to the serving cell configuration of the serving cell (first cell) indicated by the Serving Cell ID field 1851 . Accordingly, the UE can check the PCI of the second cell associated with the SSB index indicated by the SSB ID field 1855 .

At this time, the UE, in the second TRP, the beam through which the PDCCH is transmitted through the CORESET resource indicated by the CORESET ID field 1852 (and the CORESET Pool Index field 1853) is indicated by the existing TCI state ID field 1854. It can be confirmed that the transmission is carried out in the same beam as the RS configured in association with the TCI state. In addition, when the CORESET Pool index field 1853 is included, the UE may confirm that the corresponding PCI is a cell configured for the purpose of inter-cell Multi TRP operation. In this case, the TCI state ID may be reflected according to the setting of QCL-info of RRC.

According to an embodiment of the present disclosure, when the UE receives a MAC CE message including one CORESET ID field 1852 and one TCI state ID field 1854, it is interpreted as indicating a change of one PDCCH transmission beam. can do. Or, as shown below in FIG. 18D, when the UE receives a MAC CE message including a plurality of CORESET ID fields 1852 and a plurality of TCI state IDs 1854, PDCCH transmission for each CORESET of the second cell It can be interpreted that the beam is updated to each TCI state (that is, transmitted through the same beam as the RS configured in association with each TCI state).

Alternatively, one CORESET ID field 1852 and a plurality of TCI state ID fields 1854 may be included in the MAC CE. That is, the UE may determine that a plurality of TCI states are set in one CORESET ID. For example, it may be determined that each TCI state indicated by a plurality of TCI state IDs is set to be applied to correspond to a plurality of search spaces (sets) in one CORESET.

On the other hand, in another embodiment of the present disclosure, the UE receives the configuration message from the first TRP, and the MAC CE for instructing the change of the beam through which the PDCCH is transmitted in the second TRP is received from the second TRP. It is possible. To this end, PDCCH monitoring for the second cell may be performed using the above-described method, and the MAC CE may be received from the second TRP through the PDSCH scheduled by the DCI received through the PDCCH.

19 is a flowchart illustrating a method of instructing an inter-cell beam change according to the first embodiment of the present disclosure.

According to an embodiment of the present disclosure, the first node may mean a node (eg, TRP) that transmits and receives data to and from the terminal through the first cell, and the second node physically communicates with the first node. It may refer to a node (eg, TRP) that is divided or separated and transmits and receives data to and from the terminal through the second cell different from the first cell.

The first node 1910 may transmit a control message (eg, MAC CE) to the terminal 1900 in step S1905 .

In step S1910 , the terminal 1900 may check a change in the beam through which the PDCCH is transmitted from the second node 1920 based on the control message.

According to an embodiment of the present disclosure, after the terminal 1900 confirms the change of the beam, the terminal 1900 checks the beam change related control message (eg, MAC CE) through which the PDCCH is transmitted, and a response message thereto may be transmitted to the first node 1910 (not shown). In this case, the response message may be defined in MAC CE format. For example, the terminal 1900 includes a MAC subheader (subheader) including a logical channel ID (LCID) corresponding to the response message (MAC CE) and the MAC sub PDU including the response message (MAC CE) may be transmitted to the first node 1910 .

Alternatively, according to an embodiment of the present disclosure, the terminal 1900 may perform the subsequent operation without transmitting the above response message.

The second node 1920 may transmit the PDCCH to the terminal 1900 through the changed beam in step S1915. The terminal 1900 may receive the PDCCH transmitted from the second node 1920 through the changed beam.

Alternatively, the first node 1910 confirms that the control message (eg, MAC CE) has been successfully received by the terminal 1900 based on the response message, and the second node 1920, in step S1915, The PDCCH may be transmitted to the UE 1900 through the changed beam. The terminal 1900 may receive the PDCCH through the changed beam. At this time, if the first cell and the second cell are cells operated by different base stations, the first node 1910 sends the response message to the second node 1920 through a separate message (eg, an X2 interface message). is transmitted, and the second node 1920 may transmit the PDCCH to the UE 1900 through a beam changed based on this. can do.

Meanwhile, in another embodiment of the present disclosure, the UE receives the configuration message from the first node 1910, and the MAC CE for instructing the change of the beam through which the PDCCH is transmitted from the second node 1920 is the second A method of receiving from node 1920 is also possible. To this end, as described above, PDCCH monitoring for the second cell may be performed, and the MAC CE may be received from the second node 1920 through the PDSCH scheduled by the DCI received through the PDCCH.

<Second embodiment>

The second embodiment proposes a method of instructing a beam change of a serving cell and a non-serving cell through one MAC CE in an inter-cell multi TRP operation. In the present disclosure, a serving cell may be simply referred to as a first cell, and a TRP operating the first cell may be referred to as a first TRP. In addition, in the present disclosure, a non-serving cell may be simply referred to as a second cell, and a TRP operating the second cell may be referred to as a second TRP.

The UE may receive one MAC CE and simultaneously check an indication (or specify) of a change in the PDCCH transmission beam of each of the first cell and the second cell. According to an embodiment of the present disclosure, the base station may transmit information on two PDCCH beams through one signaling. In addition, the terminal can change the beam at once without distinguishing the type of TRP.

20A to 20D are diagrams illustrating a MAC CE format according to a second embodiment of the present disclosure.

Hereinafter, a method of instructing a change of the PDCCH transmission beam of each of the first cell and the second cell according to the second embodiment will be described in detail.

Example 2-1)

If a separate serving cell id is not configured in the second cell (for example, it may be the case that there is no ServCellIndex or it is assumed that it is the same as the ServCellIndex of the first cell). The PCI of the second cell can be checked by using the same method as in 2 . In this case, the MAC CE for indicating (or specifying) the change of the PDCCH transmission beams of the first cell and the second cell with one MAC CE may have a structure as shown in FIG. 20A . It goes without saying that the MAC CE below can be operated even if it is not set in RRC as in method 3.

Hereinafter, an embodiment using the Extended TCI state ID will be described.

MAC CE (2010) includes Serving cell ID 1 field (2011), CORESET ID 1 field (2012), CORESET ID 2 field (2013), TCI state ID 1 field (2014), and TCI state ID 2 field (2015) can do.

According to an embodiment of the present disclosure, each Serving Cell ID field (2011) is 5 bits, the CORESET ID 1 field (2012) is 5 bits, the CORESET ID 2 field (2013) is 5 bits, and the TCI state ID 1 field (2014) is 7 bits (or 8 bits), the TCI state ID 2 field 2015 may have a length of 7 bits (or 8 bits). However, the order of the fields and the number of bits in each field are merely examples and are not limited thereto. In addition, not all of the fields (or information) should be included in the MAC CE, and some fields may be omitted or some fields may be added.

As in the method 1 described above, since the TCI state setting for the first cell and the PCI of the second cell are already associated and set in the RRC setting process of the serving cell, in the MAC CE, the identifier of the second cell (eg PCI) It is possible to indicate the beam change or update configuration of the PDCCH while omitting .

The UE may refer to the serving cell configuration of the cell (first cell) indicated by the Serving Cell ID 1 field 2011 . At this time, CORESET ID 1 means the CORESET index of the cell (first cell) indicated by the Serving cell ID 1 field (2011), and CORESET ID 2 is implicit in the TCI state setting indicated by the TCI state ID 2 field (2015). It may mean the CORESET index of the PCI cell (second cell). Therefore, the UE can confirm that the cell indicated by the Serving cell ID 1 field (2011) is the first cell, and the PCI of the second cell is performed through the PCI embedded in the TCI state setting indicated by the TCI state ID 2 field (2015). can be checked

In this case, the UE transmits the PDCCH through the CORESET resource indicated by the CORESET ID 1 field 2012 in the first TRP is the same beam as the RS set in association with the TCI state indicated by the TCI state ID 1 field 2014 It can be confirmed that it is transmitted to At the same time, the UE transmits the PDCCH beam through the CORESET resource indicated by the CORESET ID 2 field 2013 in the second TRP is set in association with the TCI state indicated by the TCI state ID 2 field 2015 Same as RS. It can be confirmed that the beam is transmitted. In this case, the TCI state ID may be reflected according to the setting of QCL-info of RRC.

According to an embodiment of the present disclosure, upon reception of a MAC CE message including one CORESET ID field and one TCI state ID field for one cell (first cell or second cell), one PDCCH transmission beam It can be interpreted as indicating a change. Alternatively, upon receiving a MAC CE message including a plurality of CORESET fields and a plurality of TCI state ID fields for one cell, the UE updates the PDCCH transmission beam for each CORESET for one cell to each TCI state (that is, each It can be interpreted as being transmitted through the same beam as the RS configured in connection with the TCI state).

Alternatively, although an example has been described in which one TCI state ID corresponds to one CORESET ID, it is also possible to include a plurality of TCI state IDs. That is, when a plurality of TCI state fields are configured in one CORESET ID, the UE may determine that a plurality of TCI states are set. For example, it may be determined that a plurality of TCI state IDs are set to be applied to correspond to a plurality of search spaces (sets) in one CORESET.

Example 2-2)

If a separate serving cell id is not configured in the second cell (for example, it may be the case that there is no ServCellIndex or it is assumed that it is the same as the ServCellIndex of the first cell), the above-described embodiment 1-1) or embodiment 1 -2) can be used to check the PCI of the second cell. In this case, the MAC CE for indicating (or specifying) the change of the PDCCH transmission beams of the first cell and the second cell with one MAC CE may have a structure as shown in FIG. 20B . It goes without saying that the MAC CE below can be operated even if it is not set in RRC as in method 3.

Hereinafter, an embodiment using PCI will be described.

MAC CE (2020) is 5 bits of Serving cell ID 1 field 2021, PCI field 2022, CORESET ID 1 field 2023, CORESET ID 2 field 2024, TCI state ID 1 field 2025, TCI state ID 2 field 2026 .

According to an embodiment of the present disclosure, each of the Serving Cell ID field 2021 is 5 bits, the PCI field 2022 is 10 bits, the CORESET ID 1 field 2023 is 4 bits (or 5 bits), and the CORESET ID 2 field 2024 is 4 bits (or 5 bits), the TCI state ID 1 field 2025 may have a length of 7 bits, and the TCI state ID 2 field 2026 may have a length of 7 bits. However, the order of the fields and the number of bits of each field are merely examples and are not limited thereto. In addition, not all of the fields (or information) should be included in the MAC CE, and some fields may be omitted or some fields may be added.

As in method 1 described above, since the PCI of the second cell is already associated in the TCI state setting for the first cell, MAC CE omits the identifier of the second cell (eg PCI) and changes the beam of the PDCCH Or you can instruct the update settings.

The UE may identify a cell (second cell) having PCI indicated by the PCI field 2022 . At this time, CORESET ID 1 means the CORESET index of the cell (first cell) indicated by the serving cell ID 1 field 2021, and CORESET ID 2 is the CORESET index of the cell (second cell) indicated by the PCI field 2022. can mean Accordingly, the UE can confirm that the cell indicated by the Serving cell ID 1 field 2021 is the first cell, and can identify the PCI of the second cell through the PCI field 2022 .

At this time, the UE, in the first TRP, the beam through which the PDCCH is transmitted through the CORESET resource indicated by the CORESET ID 1 field 2022 is linked to the TCI state indicated by the TCI state ID 1 field 2025. It can be confirmed that the beam is transmitted. At the same time, the UE transmits the PDCCH through the CORESET resource indicated by the CORESET ID 2 field 2024 in the second TRP is the same beam as the RS set in association with the TCI state indicated by the TCI state ID 2 field 2026 It can be confirmed that it is transmitted to In this case, the TCI state ID may be reflected according to the setting of QCL-info of RRC.

According to an embodiment of the present disclosure, upon reception of a MAC CE message including one CORESET ID field and one TCI state ID field for one cell (first cell or second cell), one PDCCH transmission beam It can be interpreted as indicating a change. Alternatively, upon receiving a MAC CE message including a plurality of CORESET fields and a plurality of TCI state ID fields for one cell, the UE updates the PDCCH transmission beam for each CORESET for one cell to each TCI state (that is, each It can be interpreted as being transmitted through the same beam as the RS configured in connection with the TCI state).

Alternatively, although an example has been described in which one TCI state ID corresponds to one CORESET ID, it is also possible to include a plurality of TCI state IDs. That is, when a plurality of TCI state fields are configured in one CORESET ID, the UE may determine that a plurality of TCI states are set. For example, it may be determined that a plurality of TCI state IDs are set to be applied to correspond to a plurality of search spaces (sets) in one CORESET.

Example 2-3)

When a separate serving cell id (eg, ServCellIndex) is configured in the second cell, the Serving Cell ID field 2031 can be used as it is or partially extended to indicate a change in the beam through which the PDCCH is transmitted in the second TRP. . Since the second cell has a serving cell configuration according to an independent ServCellIndex, and one PCI can be allocated per ServCellIndex, the ServCellIndex and PCI of the second cell can be indicated through the Serving Cell ID field 2031 .

As described above, in a state in which a separate ServCellIndex (serving cell ID) is configured in the second cell through the RRC configuration information, the MAC CE for instructing (or specifying) the change of the PDCCH beam is as shown in FIG. 20C . can have a structure. Of course, it is also possible to utilize the PCI described above.

Hereinafter, an embodiment using an additional bit(s) for an inter cell will be described.

MAC CE (2030) includes a Serving Cell ID field (2031), an identifier field that additionally defines an inter cell (eg, an Intercell field) (2032), a CORESET ID 1 field (2033), and a CORESET ID 2 field in addition to the basic serving cell ID. 2034 , a TCI state ID 1 field 2035 , and a TCI state ID 2 field 2036 may be included.

According to an embodiment of the present disclosure, each of the Serving Cell ID field 2031 is 5 bits, the Intercell field 2032 is 1 bit (1 to 4 bits), the CORESET ID 1 field 2033 is 4 bits (or 5 bits), CORESET ID 2 The field 2034 may have a length of 4 bits (or 5 bits), the TCI state ID 1 field 2035 may have a length of 7 bits, and the TCI state ID 2 field 2036 may have a length of 7 bits. However, the order of the fields and the number of bits of each field are merely examples and are not limited thereto. In addition, not all of the fields (or information) should be included in the MAC CE, and some fields may be omitted or some fields may be added.

Here, the inter cell identifier field 2032 may be used to distinguish it from the ServCellindex used for the existing carrier aggregation (CA). For example, in the above-described RRC configuration, whether the ServCellIndex of the second cell is for CA or for inter-cell Multi TRP operation may not be distinguished. In this case, when the value of the inter cell identifier field 2032 is indicated as 1, the UE may determine that the ServCellIndex of the second cell configured in a higher layer (eg, RRC) is for inter-cell Multi TRP. In another embodiment, CA and inter-cell Multi TRP operation may be independently configured in the above-described RRC configuration. For example, in the RRC configuration, ServCellIndex for CA operation and ServCellndex for inter-cell Multi TRP operation may be separately configured. In this case, since the UE can determine for which operation the ServCellIndex of the second cell configured in a higher layer (eg, RRC) is used, in this case, the inter cell identifier field 2032 may be omitted. That is, when ServCellIndex is set to be clearly distinguished for the purpose of carrier aggregation in RRC configuration, the inter cell identifier field 2032 may be unnecessary, and if it is implicitly indicated without distinction, the inter cell identifier field 2032 may be required.

In this embodiment, the case where the inter cell identifier field 2032 is 1 bit is illustrated, but it may be extended to a plurality of bits according to the number of non-serving cells linked for the inter-cell Multi TRP operation with a specific serving cell.

If the inter cell identifier field 2032 is indicated as 1 and the Serving Cell ID field 2031 has a value other than 0, the UE is a serving cell of the cell (second cell) indicated by the Serving Cell ID field 2031 . You can check the PCI of the second cell through the setting. Also, it may be assumed that the first cell is a PCell with ServCellID = 0. Accordingly, the UE can confirm that the PCell with ServCellID = 0 is the first cell, and can confirm that the cell indicated by the Serving Cell ID field 2031 (and the inter cell identifier field 2032 ) is the second cell.

At this time, the UE, in the first TRP, the beam through which the PDCCH is transmitted through the CORESET resource indicated by the CORESET ID 1 field 2033 is linked to the TCI state indicated by the TCI state ID 1 field 2035. It can be confirmed that the beam is transmitted. At the same time, in the second TRP, the beam through which the PDCCH is transmitted through the CORESET resource indicated by the CORESET ID 2 field 2034 is the same beam as the RS set in association with the TCI state ID indicated by the TCI state ID 2 field 2036. can confirm that it is being transmitted. In this case, the TCI state ID may be reflected according to the setting of QCL-info of RRC. Alternatively, when the inter cell identifier field 2032 is indicated as 0, it may be assumed that only TCI states ID 1 exists.

According to an embodiment of the present disclosure, upon reception of a MAC CE message including one CORESET ID field and one TCI state ID field for one cell (first cell or second cell), one PDCCH transmission beam It can be interpreted as indicating a change. Alternatively, upon receiving a MAC CE message including a plurality of CORESET fields and a plurality of TCI state ID fields for one cell, the UE updates the PDCCH transmission beam for each CORESET for one cell to each TCI state (that is, each It can be interpreted as being transmitted through the same beam as the RS configured in connection with the TCI state).

Alternatively, although an example has been described in which one TCI state ID corresponds to one CORESET ID, it is also possible to include a plurality of TCI state IDs. That is, when a plurality of TCI state fields are configured in one CORESET ID, the UE may determine that a plurality of TCI states are set. For example, it may be determined that a plurality of TCI state IDs are set to be applied to correspond to a plurality of search spaces (sets) in one CORESET.

Example 2-4)

When a separate serving cell id (eg, ServCellIndex) is configured in the second cell, a plurality of Serving Cell ID fields (2041, 2042) are used to indicate the change of the PDCCH transmission beam of each of the first cell and the second cell. can In other words, the first cell and the second cell have independent serving cell settings according to ServCellIndex, and one PCI may be allocated per ServCellIndex. Accordingly, the first cell may be indicated through the Serving Cell ID 1 field 2041 and the second cell may be indicated through the Serving Cell ID 2 field 2042 .

As described above, in a state in which a separate ServCellIndex (serving cell ID) is configured in the second cell through the RRC configuration information, the change of the PDCCH transmission beams of the first cell and the second cell is indicated by one MAC CE (or For specifying), the MAC CE may have a structure as shown in FIG. 20D .

Hereinafter, an embodiment using a separate serving cell ID will be described.

MAC CE 2040 is Serving Cell ID 1 field 2041, Serving Cell ID 2 field 2042, CORESET ID 1 field 2043, CORESET ID 2 field 2044, TCI state ID 1 field 2045, TCI It may include a state ID 2 field 2046 .

According to an embodiment of the present disclosure, each of the Serving Cell ID 1 field 2041 is 5 bits, the Serving Cell ID 2 field 2042 is 5 bits, the CORESET ID 1 field 2043 is 4 bits (or 5 bits), and the CORESET ID 2 field 2044 may have 4 bits (or 5 bits), the TCI state ID 1 field 2045 may have 7 bits, and the TCI state ID 2 field 2046 may have 7 bits. However, the order of the fields and the number of bits of each field are merely examples and are not limited thereto. In addition, not all fields (or information) should be included in the MAC CE, and some fields may be omitted or fields may be added.

The UE may confirm that the cell indicated by the Serving Cell ID 1 field 2041 is the first cell, and may confirm that the cell indicated by the Serving Cell ID 2 field 2042 is the second cell.

At this time, the UE, in the first TRP, the beam through which the PDCCH is transmitted through the CORESET resource indicated by the CORESET ID 1 field 2043 is linked to the TCI state indicated by the TCI state ID 1 field 2045. It can be confirmed that the beam is transmitted. At the same time, in the second TRP, the beam through which the PDCCH is transmitted through the CORESET resource indicated by the CORESET ID 2 field 2044 is the same beam as the RS set in association with the TCI state ID indicated by the TCI state ID 2 field 2046. can confirm that it is being transmitted. In this case, the TCI state ID may be reflected according to the setting of QCL-info of RRC.

According to an embodiment of the present disclosure, when a MAC CE message including one CORESET ID field and one TCI state ID field is received for one cell (first cell or second cell), one PDCCH transmission beam It can be interpreted as indicating a change. Alternatively, upon receiving a MAC CE message including a plurality of CORESET fields and a plurality of TCI state ID fields for one cell, the UE updates the PDCCH transmission beam for each CORESET for one cell to each TCI state (that is, each It can be interpreted as being transmitted through the same beam as the RS configured in connection with the TCI state).

Alternatively, although an example has been described in which one TCI state ID corresponds to one CORESET ID, it is also possible to include a plurality of TCI state IDs. That is, when a plurality of TCI state fields are configured in one CORESET ID, the UE may determine that a plurality of TCI states are set. For example, it may be determined that a plurality of TCI state IDs are set to be applied to correspond to a plurality of search spaces (sets) in one CORESET.

On the other hand, in another embodiment of the present disclosure, the UE receives the configuration message in the first TRP, and the MAC CE for simultaneously indicating the change of the beam through which the PDCCH is transmitted in the first TRP and the second TRP is the second It is also possible to receive from TRP. To this end, as described above, PDCCH monitoring for the second cell may be performed, and the MAC CE may be received from the second TRP through the PDSCH scheduled by the DCI received through the PDCCH.

21 is a flowchart illustrating a method of simultaneously instructing to change beams of a first cell and a second cell through one control message according to a second embodiment of the present disclosure.

According to an embodiment of the present disclosure, the first node may mean a node (eg, TRP) that transmits and receives data to and from the terminal through the first cell, and the second node is physically connected to the first node. It may refer to a node (eg, TRP) that is divided or separated and transmits and receives data to and from the terminal through the second cell different from the first cell.

The first node 2110 may transmit a control message (eg, MAC CE) to the terminal 2100 in step S2105 .

In step S2110 , the terminal 2100 may check a change in a beam through which each PDCCH is transmitted from at least one of the first node 2110 and the second node 2120 based on the control message.

According to an embodiment of the present disclosure, after the terminal 2100 confirms the change of the beam, the terminal 2100 checks the change-related control message (eg, MAC CE) of the beam through which the PDCCH is transmitted, and a response message thereto may be transmitted to the first node 2110 (not shown). In this case, the response message may be defined in MAC CE format. For example, the terminal 2100 includes a MAC subheader (subheader) including a logical channel ID (LCID) corresponding to the response message (MAC CE) and the MAC sub PDU including the response message (MAC CE) may be transmitted to the first node 2110 .

Alternatively, according to an embodiment of the present disclosure, the terminal 2100 may perform the subsequent operation without transmitting the above response message.

The first node 2110 or the second node 2120 may transmit the PDCCH to the terminal 2100 through the changed beam in step S2115. The terminal 2100 may receive each transmitted PDCCH from at least one of the first node 2110 and the second node 2120 through the changed beam.

Alternatively, the first node 2110 confirms that the control message (eg, MAC CE) has been successfully received by the terminal 2100 based on the response message, and the first node 2110 or the second node ( The 2120 may transmit the PDCCH to the terminal 2100 through the changed beam in step S2115. The terminal 2100 may receive each transmitted PDCCH from at least one of the first node 2110 and the second node 2120 through the changed beam. At this time, if the first cell and the second cell are cells operated by different base stations, the first node 2110 sends the response message to the second node 2120 through a separate message (eg, an X2 interface message). is transmitted, and the second node 2120 may transmit the PDCCH to the terminal 1900 through a beam changed based on this.

Meanwhile, in another embodiment of the present disclosure, the terminal receives the configuration message from the first node 2110, and each PDCCH is transmitted from at least one of the first node 2110 and the second node 2120. A method of receiving the MAC CE for instructing the change of m from the second node 2120 is also possible. To this end, as described above, PDCCH monitoring for the second cell may be performed, and the MAC CE may be received from the second node 2120 through the PDSCH scheduled by the DCI received through the PDCCH.

22 is a flowchart illustrating an operation of a terminal according to the first embodiment of the present disclosure.

In step S2205, the terminal may report to the base station the terminal capability information (eg, UE capability) related to the multi-TRP operation to the base station. On the other hand, when the base station has previously received or already stored the terminal capability, step S2205 may be omitted.

In step S2210, the UE may receive a configuration message (eg, RRC message) including configuration information related to (Inter-cell) Multi TRP operation.

In step S2215, the terminal may receive a control message (eg, MAC CE) through the first node.

In step S2220, based on the information included in the configuration message or the control message, the terminal checks the change of the beam through which the PDCCH is transmitted in the second node, and can receive the PDCCH from the second node through the changed beam. there is.

23 is a flowchart illustrating an operation of a terminal according to a second embodiment of the present disclosure.

The terminal may report to the base station multi-TRP operation-related terminal capability information (eg, UE capability) to the base station in step S2305. On the other hand, if the base station has previously received or already stored the terminal capability, step S2305 may be omitted.

In step S2310, the UE may receive a configuration message (eg, RRC message) including configuration information related to the (Inter-cell) Multi TRP operation.

In step S2315, the terminal may receive a control message (eg, MAC CE) through the first node.

In step S2320, the terminal checks the change of the beam through which each PDCCH is transmitted from at least one of the first node and the second node based on the information included in the configuration message or the control message, and uses the changed beam The PDCCH may be received from at least one of the first node and the second node.

24 is a flowchart illustrating an operation of a base station according to an embodiment of the present disclosure.

In the present disclosure, a serving cell may be simply referred to as a first cell, and a non-serving cell may be simply referred to as a second cell. In this case, the first cell and the second cell may mean each cell operated by a plurality of base stations, or may mean a plurality of cells operated by one base station. The first node may mean a TRP for transmitting and receiving data to and from the terminal through the first cell, and the second node is physically separated or separated from the first node and is a terminal through a second cell different from the first cell and TRP for transmitting and receiving data.

The base station may receive multi-TRP operation-related terminal capability information (eg, UE capability) in step S2405. On the other hand, if the base station has previously received or already stored the terminal capability, step S2405 may be omitted.

The base station may transmit a configuration message (eg, an RRC message) including configuration information related to the (Inter-cell) Multi TRP operation in step S2410.

The base station may transmit a control message (eg, MAC CE) in step S2415. The control message may be used to instruct the UE to change the beam through which the PDDCH is transmitted in the second node.

When the first cell and the second cell are a plurality of cells operated by the base station, the base station may transmit a PDCCH to the terminal through a beam changed by the second node.

25 is a diagram illustrating a structure of a terminal according to an embodiment of the present disclosure.

Referring to FIG. 25 , the terminal may include a transceiver 2510 , a controller 2520 , and a storage 2530 . In the present invention, the controller may be defined as a circuit or an application specific integrated circuit or at least one processor.

The transceiver 2510 may transmit/receive signals to and from other network entities. The transceiver 2510 may receive, for example, system information from a base station, and may receive a synchronization signal or a reference signal.

The controller 2520 may control the overall operation of the terminal according to the embodiment proposed in the present invention. For example, the controller 2520 may control a signal flow between blocks to perform an operation according to the above-described flowchart. Specifically, according to an embodiment of the present invention, the controller 2520 may control to receive a control message instructing a PDCCH beam change or update operation of each TRP in an inter-cell multi TRP operation. In addition, it is possible to control to receive a control message indicating a PDCCH beam change or update operation of each TRP for two or more different cells (eg, serving cell, non-serving cell) at once.

The storage unit 2530 may store at least one of information transmitted and received through the transceiver 2510 and information generated through the control unit 2520 . For example, the storage unit 2530 may store configuration information (eg, information included in an RRC message) for an inter-cell Multi TRP operation.

26 is a diagram illustrating a structure of a base station according to an embodiment of the present disclosure.

Referring to FIG. 26 , the base station may include a transceiver 2610 , a control unit 2620 , and a storage unit 2630 . In the present invention, the controller may be defined as a circuit or an application specific integrated circuit or at least one processor.

The transceiver 2610 may transmit/receive signals to and from other network entities. The transceiver 2610 may transmit, for example, system information to the terminal, and may transmit a synchronization signal or a reference signal.

The controller 2620 may control the overall operation of the base station according to the embodiment proposed in the present invention. For example, the controller 2620 may control a signal flow between blocks to perform an operation according to the above-described flowchart. Specifically, the controller 2620 may control to transmit a control message instructing a PDCCH beam change or update operation of each TRP in an inter-cell Multi TRP operation according to an embodiment of the present invention. In addition, it is possible to control to transmit a control message indicating a PDCCH beam change or update operation of each TRP for two or more different cells (eg, serving cell, non-serving cell) at once.

The storage unit 2630 may store at least one of information transmitted and received through the transceiver 2610 and information generated through the control unit 2520 . For example, the storage unit 2630 may store configuration information (eg, information included in an RRC message) for an inter-cell Multi TRP operation.

The embodiments of the present invention disclosed in the present specification and drawings are merely provided for specific examples in order to easily explain the technical contents of the present invention and help the understanding of the present invention, and are not intended to limit the scope of the present invention. It will be apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein.

Claims (15)

1. In the method of a terminal of a wireless communication system,

   Receiving a configuration message related to an inter-cell multi-transmission reception point (multi-TRP) operation;

   receiving a control message from a node of a first cell related to the inter-cell multi-TRP operation;

   checking a change in a beam through which a physical downlink control channel (PDCCH) is transmitted from a node of a second cell related to the inter-cell multi-TRP operation based on the configuration message and the control message; and

   and receiving the PDCCH from the node of the second cell through the changed beam based on the confirmation result.
2. According to claim 1,

   The control message includes information on a control resource set (CORESET) and information on a transmission configuration indicator state (transmission configuration indicator state, TCI state),

   The PDCCH is related to the information on the CORESET,

   The changed beam corresponds to information on the TCI state,

   The configuration message is a radio resource control (radio resource control, RRC) message,

   The control message is a method, characterized in that the medium access control control element (medium access control control element, MAC CE).
3. According to claim 1,

   The method of claim 1, wherein the second cell corresponds to a physical cell ID (PCI) identified based on at least one of the configuration message and the control message.
4. According to claim 1,

   The second cell method, characterized in that it corresponds to a serving cell index (serving cell index) included in the control message.
5. According to claim 1,

   The control message further includes information on a change in a beam through which the PDCCH is transmitted from the node of the first cell,

   Based on the configuration message and the control message, it is characterized in that the change of the beam through which the PDCCH is transmitted is confirmed from at least one of the node of the first cell and the node of the second cell.
6. In the method of a base station of a wireless communication system,

   Transmitting a configuration message related to an inter-cell multi-transmission reception point (multi-TRP) operation to the terminal; and

   Transmitting a control message to the terminal through a node of a first cell related to the inter-cell multi-TRP operation,

   The change in the beam through which a physical downlink control channel (PDCCH) is transmitted from the node of the second cell related to the inter-cell multi-TRP operation includes the configuration information included in the configuration message and the control message. A method, characterized in that it is based on the control information.
7. 7. The method of claim 6,

   The control message includes information on a control resource set (CORESET), information on a transmission configuration indicator state (TCI state), and a beam through which the PDCCH is transmitted from the node of the first cell. including information about the change;

   The PDCCH is related to the information on the CORESET,

   The changed beam corresponds to information on the TCI state,

   The change of the beam through which the PDCCH is transmitted from at least one of the node of the first cell and the node of the second cell is based on the configuration message and the control message,

   The configuration message is a radio resource control (radio resource control, RRC) message,

   The control message is a method, characterized in that the medium access control control element (medium access control control element, MAC CE).
8. In the terminal of a wireless communication system,

   transceiver; and

   Controls the transceiver to receive a configuration message related to an inter-cell multi-transmission reception point (multi-TRP) operation, and controls the transceiver of the first cell related to the inter-cell multi-TRP operation. Controls the transceiver to receive a control message from a node, and based on the configuration message and the control message, a physical downlink control channel (physical downlink) from the node of the second cell related to the inter-cell multi-TRP operation A control channel (PDCCH) including a control unit that controls to confirm a change in a transmitted beam, and controls the transceiver to receive the PDCCH from a node of the second cell through the changed beam based on a result of the confirmation A terminal, characterized in that.
9. 9. The method of claim 8,

   The control message includes information on a control resource set (CORESET) and information on a transmission configuration indicator state (transmission configuration indicator state, TCI state),

   The PDCCH is related to the information on the CORESET,

   The changed beam corresponds to information on the TCI state,

   The configuration message is a radio resource control (radio resource control, RRC) message,

   The control message is a terminal, characterized in that the medium access control control element (medium access control control element, MAC CE).
10. 9. The method of claim 8,

    The second cell corresponds to a physical cell ID (PCI) that is identified based on at least one of the configuration message and the control message.
11. 9. The method of claim 8,

    The second cell terminal, characterized in that it corresponds to a serving cell index (serving cell index) included in the control message.
12. 9. The method of claim 8,

    The control message further includes information on a change in a beam through which the PDCCH is transmitted from the node of the first cell,

    Based on the configuration message and the control message, the terminal characterized in that the change of the beam through which the PDCCH is transmitted is confirmed from at least one of the node of the first cell and the node of the second cell.
13. In a base station of a wireless communication system,

    transceiver; and

    Controls the transceiver to transmit a configuration message related to an inter-cell multi-transmission reception point (multi-TRP) operation to the terminal, and controls the transceiver to transmit a first information related to the inter-cell multi-TRP operation A control unit for controlling the transceiver to transmit a control message to the terminal through a node of a cell,

    The change in the beam through which a physical downlink control channel (PDCCH) is transmitted from the node of the second cell related to the inter-cell multi-TRP operation includes the configuration information included in the configuration message and the control message. Base station, characterized in that based on the control information.
14. 14. The method of claim 13,

    The control message includes information on a control resource set (CORESET) and information on a transmission configuration indicator state (transmission configuration indicator state, TCI state),

    The PDCCH is related to the information on the CORESET,

    The changed beam corresponds to information on the TCI state,

    The configuration message is a radio resource control (radio resource control, RRC) message,

    The control message is a base station, characterized in that the medium access control control element (medium access control control element, MAC CE).
15. 14. The method of claim 13,

    The control message further includes information on a change in a beam through which the PDCCH is transmitted from the node of the first cell,

    The change of the beam through which the PDCCH is transmitted from at least one of the node of the first cell and the node of the second cell is based on the configuration message and the control message.

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