Terminal-based beam control according to network setting

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. The present disclosure relates to a method for supporting 5G communication or 6G communication using a high frequency band. An embodiment of the present disclosure relates to a method and an apparatus for performing beam control with low reference signal overhead in a communication system.

Description

Terminal-based beam control based on network settings

[0001] The present disclosure generally relates to the operation of a terminal and a base station in a communication system. More specifically, the present disclosure relates to a beam control method and device in a communication system.

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

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

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

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

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

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

[0008] The present disclosure proposes a method for a terminal to quickly perform a required terminal beam change based on a beam reference signal in a situation where a terminal beam change is required due to a base station beam change or a change in channel conditions. In addition, the present disclosure aims to achieve a lower reference signal transmission overhead and improved beam selection accuracy of the terminal compared to existing techniques.

[0009] The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by a person having ordinary skill in the technical field to which the present disclosure belongs from the description below.

[0010] A method performed by a terminal in a communication system according to one embodiment of the present disclosure may include the steps of: receiving configuration information for a downlink reference signal (DL RS) related to beam management (BM) through upper layer signaling; receiving downlink control information (DCI) for scheduling a data channel based on a physical downlink control channel (PDCCH) of a first terminal beam, the DCI including information related to triggering the DL RS; receiving the DL RS based on the configuration information and the DCI; identifying a second terminal beam different from the first terminal beam based on the DL RS; and performing communication for the data channel based on the second terminal beam.

[0011] According to one embodiment of the present disclosure, the DL RS is received in at least some of the symbols between the last symbol of the PDCCH and the first symbol of the data channel, and the symbols are related to a time required for the terminal to identify the second terminal beam based on the DL RS and apply it to communication of the data channel, and the time required for the terminal can be reported as a terminal capability.

[0012] According to one embodiment of the present disclosure, when the base station beam is identified as changed based on the DCI, the DL RS can be received based on the second terminal beam, and when the base station beam is identified as not changed based on the DCI, the DL RS can be received based on the first terminal beam.

[0013] According to one embodiment of the present disclosure, when the beam of the base station is identified as changed based on the DCI, the second terminal beam is identified among the first terminal candidate beams, and the symbols between the last symbol of the PDCCH and the first symbol of the data channel are based on a first time offset, and when the beam of the base station is identified as not changed based on the DCI, the symbols between the last symbol of the PDCCH and the first symbol of the data channel are based on a second time offset, and the number of the first terminal candidate beams is greater than the number of the second terminal candidate beams, and the first time offset may be greater than the second time offset.

[0014] According to one embodiment of the present disclosure, the DL RS is received based on a plurality of antenna elements of the terminal, the plurality of antenna elements correspond to a plurality of buffers, information corresponding to the DL RS received at each antenna element is stored in each buffer corresponding to each antenna element, and the terminal beam can be identified based on the information stored in the plurality of buffers.

[0015] According to one embodiment of the present disclosure, the configuration information includes information on a plurality of DL RS resources, the DL RS is received from an activated DL RS resource among the plurality of DL RS resources, and information on the activated DL RS resource can be received through a MAC CE (medium access control control element).

[0016] According to one embodiment of the present disclosure, a terminal of a communication system includes a transceiver; and a processor connected to the transceiver, wherein the processor is configured to: receive configuration information for a downlink reference signal (DL RS) related to beam management (BM) through upper layer signaling; receive downlink control information (DCI) for scheduling a data channel based on a physical downlink control channel (PDCCH) of a first terminal beam, the DCI including information related to triggering the DL RS; receive the DL RS based on the configuration information and the DCI; identify a second terminal beam different from the first terminal beam based on the DL RS; and perform communication for the data channel based on the second terminal beam.

[0017] A method performed by a base station in a communication system according to one embodiment of the present disclosure comprises the steps of: transmitting configuration information for a downlink reference signal (DL RS) related to beam management (BM) through upper layer signaling; transmitting downlink control information (DCI) for scheduling a data channel through a physical downlink control channel (PDCCH), the DCI including information related to triggering the DL RS; transmitting the DL RS; and performing communication for the data channel, wherein a first terminal beam corresponding to the PDCCH is different from a second terminal beam corresponding to the data communication, and the second terminal beam can be based on the DL RS.

[0018] A base station of a communication system according to one embodiment of the present disclosure includes a transceiver; and a processor connected to the transceiver, wherein the processor is configured to: transmit configuration information for a downlink reference signal (DL RS) related to beam management (BM) through upper layer signaling; transmit a physical downlink control channel (PDCCH) with downlink control information (DCI) for scheduling a data channel, the DCI including information related to triggering the DL RS; transmit the DL RS; and perform communication for the data channel, wherein a first terminal beam corresponding to the PDCCH is different from a second terminal beam corresponding to the data communication, and the second terminal beam can be based on the DL RS.

[0019] According to one embodiment of the present disclosure, it is possible to quickly perform beam modification or change of a terminal based on a beam reference signal, thereby enabling the application of superior beam performance to communications. Furthermore, according to one embodiment of the present disclosure, it is possible to simplify or eliminate tasks that require a lot of radio resources, such as beam pairing and beam pair update, thereby increasing radio resource efficiency.

[0020] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0021] FIG. 1 is a diagram illustrating a basic structure in the time-frequency domain in a communication system to which the present disclosure can be applied.

[0022] FIG. 2 is a diagram illustrating a frame, subframe, and slot structure in a communication system to which the present disclosure can be applied.

[0023] FIG. 3 is a diagram illustrating an example of setting a control region of a downlink control channel in a communication system to which the present disclosure can be applied.

[0024] FIG. 4 is a diagram illustrating an example of base station beam allocation according to a transmission configuration indicator (TCI) state setting in a communication system according to one embodiment of the present disclosure.

[0025] FIG. 5 is a diagram of a beam application time that can be considered when using an integrated TCI method in a communication system according to one embodiment of the present disclosure.

[0026] FIG. 6 is a diagram illustrating another MAC-CE structure for activating and indicating a joint TCI state or a separate DL or UL TCI state in a communication system according to one embodiment of the present disclosure.

[0027] FIG. 7 is a diagram illustrating an example of sub-array-based analog beamforming and digital beamforming mixing in a communication system to which the present disclosure can be applied.

[0028] FIG. 8 is a diagram illustrating an example of an analog beam setting method that can be supported in a communication system to which the present disclosure can be applied.

[0029] FIG. 9 is a diagram illustrating an example of a beam sweeping procedure for beam pairing in a communication system to which the present disclosure can be applied.

[0030] FIG. 10 is a diagram illustrating an example of a beam pair-based terminal beam modification procedure in a communication system to which the present disclosure can be applied.

[0031] FIG. 11 is a diagram illustrating an example of terminal reception beam settings in a communication system to which the present disclosure can be applied.

[0032] FIG. 12 is a diagram illustrating an example of a terminal beam change procedure before data transmission and reception according to one embodiment of the present disclosure.

[0033] FIG. 13 is a diagram illustrating an example of terminal operation for rapid terminal beam correction according to one embodiment of the present disclosure.

[0034] FIG. 14 is a diagram illustrating an example of a front-loaded BMRS according to one embodiment of the present disclosure.

[0035] FIG. 15 is a diagram illustrating an example of a front-loaded BMRS according to one embodiment of the present disclosure.

[0036] FIG. 16 is a diagram showing an example of terminal operation according to one embodiment of the present disclosure.

[0037] FIG. 17 is a diagram illustrating an example of base station operation according to one embodiment of the present disclosure.

[0038] FIG. 18 is a diagram illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0039] FIG. 19 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0040] The operating principles of the present disclosure are described in detail below with reference to the attached drawings. In the following description of the present disclosure, detailed descriptions of related known functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Furthermore, the terms described below are defined based on the functions of the present disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the overall content of this specification.

[0041] In the following description of the present disclosure, detailed descriptions of related known functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Hereinafter, embodiments of the present disclosure will be described with reference to the attached drawings.

[0042] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification. In addition, when describing the present disclosure, if a specific description of a related function or configuration is determined to unnecessarily obscure the gist of the present disclosure, the detailed description thereof will be omitted. In addition, the terms described below are terms defined in consideration of the functions of the present disclosure, and these may vary depending on the intention or custom of the user or operator. Therefore, their definitions should be made based on the contents throughout the specification.

[0043] Hereinafter, the base station is an entity that performs resource allocation of the terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station to a terminal, and uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station. In addition, although the LTE or LTE-A system may be described below as an example, the embodiments of the present disclosure may also be applied to other communication systems having a similar technical background or channel type. For example, the 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included here, and the 5G below may also be a concept that includes existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems with some modifications within a scope that does not significantly deviate from the scope of the present disclosure, as judged by a person having skilled technical knowledge.

[0044] At this time, it will be understood that each block of the processing flowchart drawings and combinations of the flowchart drawings can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flowchart block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flowchart block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0045] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0046] Here, the term '~ part' used in this embodiment means software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and the '~ part' performs certain roles. However, the '~ part' is not limited to software or hardware. The '~ part' may be configured to be on an addressable storage medium or may be configured to play one or more processors. Therefore, as an example, the '~ part' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ parts' may be combined into a smaller number of components and '~ parts' or further separated into additional components and '~ parts'. Additionally, the components and '~parts' may be implemented to activate one or more CPUs within a device or secure multimedia card. In addition, in an embodiment, the '~parts' may include one or more processors.

[0047] To meet the growing demand for wireless data traffic following the commercialization of 4G (4th generation) communication systems, efforts are being made to develop improved 5G (5th generation) communication systems, or pre-5G communication systems. For this reason, 5G communication systems, or pre-5G communication systems, are also referred to as "Beyond 4G Network" communication systems or "Post-LTE" systems.

[0048] To achieve high data rates, 5G communication systems are being considered for implementation in ultra-high frequency (mmWave) bands (e.g., 60 GHz bands). To mitigate radio path loss and increase the transmission range of radio waves in ultra-high frequency bands, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large-scale antenna technologies are being discussed in 5G communication systems.

[0049] In addition, to improve the network of the system, technologies such as evolved small cells, advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, moving networks, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation are being developed in 5G communication systems.

[0050] In addition, advanced coding modulation (ACM) methods such as FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), as well as advanced access technologies such as FBMC (Filter Bank Multi Carrier), NOMA (non-orthogonal multiple access), and SCMA (sparse code multiple access) are being developed in 5G systems.

[0051] 5G systems are considering supporting a wider range of services compared to existing 4G systems. For example, representative services include enhanced mobile broadband (eMBB), ultra-reliable and low latency communication (URLLC), massive machine type communication (mMTC), and evolved multimedia broadcast / multicast service (eMBMS). A system that provides URLLC services may be referred to as a URLLC system, and a system that provides eMBB services may be referred to as an eMBB system. Furthermore, the terms "service" and "system" may be used interchangeably.

[0052] Among these, URLLC service is a new service being considered in the 5G system, unlike the existing 4G system, and has ultra-high reliability (e.g., packet error rate of about 10) compared to other services. -5 ) and low latency (e.g., approximately 0.5 msec) conditions. To meet these stringent requirements, URLLC services may need to apply a shorter transmission time interval (TTI) than eMBB services, and various operation methods utilizing this are being considered.

[0053] Meanwhile, the Internet is evolving from a human-centric network where humans create and consume information to an Internet of Things (IoT) network where information is exchanged and processed between distributed components such as objects. The Internet of Everything (IoE) technology, which combines IoT technology with big data processing technology through connections to cloud servers, is also emerging. To implement IoT, technological elements such as sensing technology, wireless communication and network infrastructure, service interface technology, and security technology are required. Recently, technologies such as sensor networks for connecting objects, machine-to-machine (M2M), and machine-type communication (MTC) are being studied.

[0054] In an IoT environment, intelligent IT (Internet Technology) services can be provided that collect and analyze data generated from connected objects, creating new value in human life. IoT can be applied to areas such as smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart appliances, and advanced medical services through the convergence and integration of existing IT (information technology) technologies with various industries.

[0055] Accordingly, various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-to-machine (M2M), and machine-type communication (MTC) are being implemented using 5G communication techniques such as beamforming, MIMO, and array antennas. The application of cloud radio access networks (cloud RAN) as a big data processing technology described above can also be said to be an example of the convergence of 5G and IoT technologies. Wireless communication systems are evolving from providing voice-oriented services in the early days to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as communication standards such as 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's HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE's 802.16e.

[0056] As a representative example of the above broadband wireless communication system, the LTE system adopts the OFDM (Orthogonal Frequency Division Multiplexing) method in the downlink (DL) and the SC-FDMA (Single Carrier Frequency Division Multiple Access) method in the uplink (UL). The uplink refers to a wireless link in which a terminal (User Equipment (UE) or Mobile Station (MS)) transmits data or control signals to a base station (eNode B or base station (BS)), and the downlink refers to a wireless link in which a base station transmits data or control signals to a terminal. The above multiple access method can distinguish the data or control information of each user by allocating and operating the time-frequency resources for transmitting data or control information to each user so that they do not overlap, that is, so as to achieve orthogonality.

[0057] As a future communications system beyond LTE, 5G communication systems must be able to freely reflect the diverse needs of users and service providers. Therefore, they must support services that simultaneously satisfy these diverse requirements. Services being considered for 5G communication systems include enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliability Low Latency Communication (URLLC).

[0058] eMBB aims to provide data transmission rates that are significantly higher than those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must be able to support a peak data rate of 20 Gbps in the downlink and a peak data rate of 10 Gbps in the uplink from the perspective of a single base station. Furthermore, 5G communication systems must simultaneously provide the peak data rate and an increased user-perceived data rate for terminals. To meet these requirements, improvements in various transmission and reception technologies, including improved multi-input, multi-output (MIMO) transmission technology, are required. Furthermore, while LTE transmits signals using a maximum transmission bandwidth of 20 MHz in the 2 GHz band, 5G communication systems can meet the data transmission rates required by 5G communication systems by using a wider frequency bandwidth than 20 MHz in the 3-6 GHz or higher 6 GHz band.

[0059] At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide the IoT, mMTC requires supporting large-scale terminal connections within a cell, improved terminal coverage, enhanced battery life, and reduced terminal costs. The IoT requires the ability to support a large number of terminals (e.g., 1,000,000 terminals / km2) within a cell, as it provides communication capabilities through the attachment of various sensors and devices. Furthermore, due to the nature of the service, terminals supporting mMTC are likely to be located in shadow areas, such as basements, beyond cell coverage. This may require broader coverage compared to other services provided by 5G communication systems. Terminals supporting mMTC must be inexpensive, and since frequent battery replacement is unlikely, they may require extremely long battery lifespans, such as 10 to 15 years.

[0060] Finally, URLLC refers to cellular-based wireless communication services used for specific mission-critical purposes. Examples include remote control of robots or machinery, industrial automation, unmanned aerial vehicles (UAVs), remote health care, and emergency alerts. Therefore, URLLC communications must offer extremely low latency and high reliability. For example, URLLC-enabled services must meet air interface latency requirements of less than 0.5 milliseconds and a packet error rate (PER) of 10-5 or lower. Therefore, for URLLC-enabled services, 5G systems must provide shorter Transmit Time Intervals (TTIs) than other services, while simultaneously allocating extensive resources in the frequency band to ensure communication link reliability.

[0061] The three 5G services—eMBB, URLLC, and mMTC—can be multiplexed and transmitted within a single system. To meet the differing requirements of each service, different transmission and reception techniques and parameters can be used. Of course, 5G is not limited to the three services described above.

[0062] Hereinafter, a / b can be understood as at least one of a or b.

[0063] The terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, and terms referring to various identification information are provided as examples for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects with equivalent technical meanings may be used.

[0064] The 5G mobile communication network is composed of 5G UE (user equipment, terminal), 5G RAN (radio access network, base station, gNB (5g nodeB), eNB (evolved nodeB, etc.), and 5G core network. The 5G core network is composed of network functions such as AMF (access and mobility management function) that provides UE mobility management function, SMF (session management function) that provides session management function, UPF (user plane function) that performs data transfer role, PCF (policy control function) that provides policy control function, UDM (unified data management) that provides data management function such as subscriber data and policy control data, and UDR (unified data repository) that stores data of various network functions such as UDM.

[0065] The present disclosure may relate to a UE oriented beam control method and procedure.

[0066] For example, the present disclosure proposes a complete process / method / procedure for performing a UE-oriented beam control technique that can perform beam selection targeting a wider variety of beams, breaking away from the conventional method in which a base station pre-selects candidate beams, a terminal reports measurement results for the candidate beams, and the base station uses one of the candidate beams for downlink, uplink, or bidirectional transmission based on the report, in performing a beam control technique, which is a core technology of mmwave communication.

[0067] For example, the present disclosure presents steps / methods / procedures by which a base station selects terminal performance requirements and, based thereon, allows each terminal to use a UE-oriented beam control technique.

[0068] For example, the present disclosure presents steps / methods / procedures for how a terminal selects a beam and, when requested by a base station, how the base station reflects it.

[0069] Hereinafter, in the description of the present disclosure, the antenna element and the antenna port (or port) may be replaced with each other. That is, in the description of the present disclosure described below, the antenna element may be replaced with the antenna port (or port), and the antenna port (or port) may be replaced with the antenna element. In addition, each of the antenna element and the antenna port (or port) may be replaced with a panel.

[0070] Hereinafter, in the description of the present disclosure, front-loaded BMRS and front-BMRS can be replaced with each other. That is, in the description of the present disclosure described below, front-loaded BMRS can be replaced with front-BMRS, and front-BMRS can be replaced with front-loaded BMRS.

[0071] FIG. 1 is a diagram illustrating a basic structure in the time-frequency domain in a communication system to which the present disclosure can be applied.

[0072] The horizontal axis of Figure 1 represents the time domain, and the vertical axis represents the frequency domain. The basic unit of resources in the time and frequency domains is a resource element (RE, 101), which can be defined as 1 OFDM (Orthogonal Frequency Division Multiplexing) symbol (102) in the time axis and 1 subcarrier (103) in the frequency axis. In the frequency domain (For example, 12) consecutive REs can form one Resource Block (RB, 104). Also, in the time domain, A number of consecutive OFDM symbols can constitute one subframe (Subframe, 110).

[0073] FIG. 2 is a diagram illustrating a frame, subframe, and slot structure in a communication system to which the present disclosure can be applied.

[0074] Figure 2 illustrates an example of a structure of a frame (Frame, 200), a subframe (Subframe, 201), and a slot (Slot, 202). One frame (200) can be defined as 10 ms. One subframe (201) can be defined as 1 ms, and therefore one frame (200) can be composed of a total of 10 subframes (201). One slot (202, 203) can be defined as 14 OFDM symbols (i.e., the number of symbols per slot ( )=14). 1 subframe (201) may be composed of one or more slots (202, 203), and the number of slots (202, 203) per 1 subframe (201) may vary depending on the setting value μ (204, 205) for the subcarrier spacing. In an example of FIG. 2, the cases where μ = 0 (204) and μ = 1 (205) as the subcarrier spacing setting value are illustrated. When μ = 0 (204), 1 subframe (201) may be composed of 1 slot (202), and when μ = 1 (205), 1 subframe (201) may be composed of 2 slots (203). That is, the number of slots per 1 subframe ( ) may vary, and accordingly the number of slots per frame ( ) may vary. Depending on the subcarrier spacing setting μ and can be defined as shown in Table 1 below.

[0075] [Table 1]

[0076]

[0077] FIG. 3 is a diagram illustrating an example of setting a control region of a downlink control channel in a communication system to which the present disclosure can be applied.

[0078] FIG. 3 is a diagram illustrating an example of CORESET in a communication system (e.g., a 5G system) to which the present disclosure can be applied.

[0079] Referring to FIG. 3, an example is illustrated in which two control regions (Control Region #1 (301), Control Region #2 (302)) are set within a UE bandwidth part (310) on the frequency axis and within one slot (420) on the time axis. The control regions (301, 302) can be set to specific frequency resources (303) within the entire UE bandwidth part (410) on the frequency axis. The time axis can be set to one or more OFDM symbols, which can be defined as the control region length (Control Resource Set Duration, 304). Referring to the illustrated example of FIG. 4, Control Region #1 (301) is set to a control region length of two symbols, and Control Region #2 (302) is set to a control region length of one symbol.

[0080] The aforementioned control region can be configured by the base station to the terminal via higher-layer signaling (e.g., System Information, Master Information Block (MIB), Radio Resource Control (RRC) signaling). Configuring a control region for the terminal means providing information such as the control region identifier (Identity), the frequency location of the control region, and the symbol length of the control region. For example, the information may include the following:

[0081] [Table 2]

[0082]

[0083]

[0084] In Table 2, the tci-StatesPDCCH (simply named TCI (Transmission Configuration Indication) state) configuration information may include information on one or more SS (Synchronization Signal) / PBCH (Physical Broadcast Channel) block indices or CSI-RS (Channel State Information Reference Signal) indices that are in a QCL (Quasi Co Located) relationship with the DMRS transmitted in the corresponding control region. [QCL, TCI state]

[0085] In a wireless communication system, one or more different antenna ports (or one or more channels, signals, and combinations thereof, but for convenience, they will be referred to as different antenna ports in the following description of the present disclosure) can be associated with each other by a QCL (Quasi co-location) setting as shown in [Table 3] below. The TCI state is to notify the QCL relationship between the PDCCH (or PDCCH DMRS) and other RSs or channels. When a reference antenna port A (reference RS #A) and another target antenna port B (target RS #B) are QCLed with each other, it means that the terminal is allowed to apply some or all of the large-scale channel parameters estimated at the antenna port A to the channel measurement from the antenna port B. QCL may need to relate different parameters depending on the situation, such as 1) time tracking affected by average delay and delay spread, 2) frequency tracking affected by Doppler shift and Doppler spread, 3) radio resource management (RRM) affected by average gain, and 4) beam management (BM) affected by spatial parameters. Accordingly, NR supports four types of QCL relationships, as shown in [Table 3] below.

[0086] [Table 3]

[0087]

[0088] The above spatial RX parameter may collectively refer to some or all of various parameters, such as Angle of arrival (AoA), Power Angular Spectrum (PAS) of AoA, Angle of departure (AoD), PAS of AoD, transmit / receive channel correlation, transmit / receive beamforming, and spatial channel correlation.

[0089] The above QCL relationship can be set to the terminal through the RRC parameters TCI-State and QCL-Info as shown in Table 4 below. Referring to Table 4, the base station can set one or more TCI states to the terminal and inform the RS referencing the ID of the TCI state, i.e., up to two QCL relationships (qcl-Type1, qcl-Type2) for the target RS. At this time, each QCL information (QCL-Info) included in the above TCI state includes the serving cell index and BWP index of the reference RS indicated by the corresponding QCL information, the type and ID of the reference RS, and the QCL type as shown in Table 3 above.

[0090] [Table 4]

[0091]

[0092] FIG. 4 is a diagram illustrating an example of base station beam allocation according to a transmission configuration indicator (TCI) state setting in a communication system according to one embodiment of the present disclosure.

[0093] Referring to FIG. 4, the base station can transmit information about N different beams to the terminal through N different TCI states. For example, in case of N=3 as shown in FIG. 4, the base station can notify that the antenna ports referencing the different TCI states 400, 405, or 410 have different spatial Rx parameters, i.e., are associated with different beams, by setting the qcl-Type2 parameter included in the three TCI states (400, 405, 410) to be associated with the CSI-RS or SSB corresponding to the different beams and to QCL type D.

[0094] Tables 5 to 9 below show valid TCI state settings according to target antenna port type.

[0095] [Table 5] shows valid TCI state settings when the target antenna port is CSI-RS for tracking (i.e., TRS). The TRS refers to NZP CSI-RS with the repetition parameter not set and trs-Info set to true among CSI-RSs. Setting 3 in Table 5 can be used for aperiodic TRS.

[0096] [Table 5]

[0097] Set a valid TCI state when the target antenna port is CSI-RS for tracking (TRS).

[0098]

[0099] [Table 6] shows valid TCI state settings when the target antenna port is a CSI-RS for CSI. The CSI-RS for CSI refers to an NZP CSI-RS in which a parameter indicating repetition (e.g., repetition parameter) is not set among the CSI-RSs and trs-Info is not set to true.

[0100] [Table 6]

[0101] Set a valid TCI state when the target antenna port is CSI-RS for CSI.

[0102]

[0103] [Table 7] shows the valid TCI state settings when the target antenna port is CSI-RS for beam management (BM, synonymous with CSI-RS for L1 RSRP reporting). The CSI-RS for BM refers to an NZP CSI-RS in which the repetition parameter is set to On or Off among CSI-RSs and trs-Info is not set to true.

[0104] [Table 7]

[0105] Set a valid TCI state when the target antenna port is CSI-RS for BM (for L1 RSRP reporting).

[0106]

[0107] [Table 8] shows the valid TCI state settings when the target antenna port is PDCCH DMRS.

[0108] [Table 8]

[0109] Set a valid TCI state when the target antenna port is PDCCH DMRS.

[0110]

[0111] [Table 9] shows the valid TCI state settings when the target antenna port is PDSCH DMRS.

[0112] [Table 9]

[0113] Set a valid TCI state when the target antenna port is PDSCH DMRS.

[0114]

[0115] A representative QCL setting method according to the above [Table 5] to [Table 9] is to set and operate the target antenna port and reference antenna port for each step as "SSB" -> "TRS" -> "CSI-RS for CSI, or CSI-RS for BM, or PDCCH DMRS, or PDSCH DMRS." Through this, it is possible to link statistical characteristics that can be measured from SSB and TRS to each antenna port to assist the terminal's receiving operation.

[0116] [Unified TCI state]

[0117] Hereinafter, a single TCI state indication and activation method based on the unified TCI scheme is described. The unified TCI scheme can refer to a method of integrating and managing the transmission and reception beam management methods, which were distinguished into the TCI state method used for downlink reception of the terminal in the existing Rel-15 and 16 and the spatial relation info method used for uplink transmission, into a TCI state. Therefore, when the terminal is instructed by the base station based on the unified TCI scheme, it can perform beam management using the TCI state even for uplink transmission. If the terminal has set a TCI-State, which is an upper layer signaling with the tci-stateId-r17, which is an upper layer signaling, from the base station, the terminal can perform operations based on the unified TCI scheme using the corresponding TCI-State. The TCI-State can exist in two forms: a joint TCI state or a separate TCI state.

[0118] The first type is a joint TCI state, and the terminal can be instructed by the base station to use both the TCI state to apply to uplink transmission and downlink reception through a single TCI-State. If the terminal is instructed to use a TCI-State based on a joint TCI state, the terminal can use the RS corresponding to qcl-Type1 in the TCI-State based on the joint TCI state to instruct the parameters to use for downlink channel estimation, and the RS corresponding to qcl-Type2 to instruct the parameters to use as a downlink reception beam or reception filter. If the terminal is instructed to use a TCI-State based on a joint TCI state, the terminal can use the RS corresponding to qcl-Type2 in the TCI-State based on the joint DL / UL TCI state to instruct the parameters to use as an uplink transmission beam or transmission filter. In this case, if the terminal is instructed to use a joint TCI state, the terminal can apply the same beam to both uplink transmission and downlink reception.

[0119] The second form is a separate TCI state, in which the terminal can be individually instructed by the base station to select a UL TCI state to apply to uplink transmission and a DL TCI state to apply to downlink reception. If the terminal is instructed to select a UL TCI state, the terminal can be instructed to select parameters to use as an uplink transmission beam or transmission filter using the reference RS or source RS configured in the UL TCI state. If the terminal is instructed to select a DL TCI state, the terminal can be instructed to select parameters to use for downlink channel estimation using the RS corresponding to qcl-Type1 configured in the DL TCI state, and to select parameters to use as a downlink reception beam or reception filter using the RS corresponding to qcl-Type2.

[0120] If the terminal is instructed with both the DL TCI state and the UL TCI state, the terminal can be instructed with parameters to be used as an uplink transmission beam or a transmission filter using the reference RS or source RS set in the corresponding UL TCI state, and can be instructed with parameters to be used for downlink channel estimation using the RS corresponding to qcl-Type1 set in the corresponding DL TCI state, and can be instructed with parameters to be used as a downlink reception beam or a reception filter using the RS corresponding to qcl-Type2. In this case, if the reference RS or source RS set in the DL TCI state and UL TCI state to which the terminal is instructed are different, the terminal can individually apply beams to uplink transmission and downlink reception, respectively, based on the instructed UL TCI state and DL TCI state.

[0121] A terminal can receive a joint TCI state from a base station for each bandwidth part within a specific cell through upper layer signaling up to 128 times, and among the separate TCI states, a DL TCI state can be set for each bandwidth part within a specific cell up to 64 or 128 times through upper layer signaling based on a terminal capability report. Among the separate TCI states, the DL TCI state and the joint TCI state can use the same upper layer signaling structure. For example, if 128 joint TCI states are set and 64 DL TCI states are set among the separate TCI states, the 64 DL TCI states can be included in the 128 joint TCI states.

[0122] Among the separate TCI states, the UL TCI state can be set to a maximum of 32 or 64 upper layer signaling for each specific bandwidth part within a specific cell based on the terminal capability report, and like the relationship between the DL TCI state and the joint TCI state among the separate TCI states, the UL TCI state and the joint TCI state among the separate TCI can also use the same upper layer signaling structure, and the UL TCI state among the separate TCI can use different upper layer signaling structures from the joint TCI state and the DL TCI state among the separate TCI states.

[0123] The use of different or identical upper layer signaling structures may be defined in the specification, or may be distinguished through another upper layer signaling established by the base station based on a terminal capability report containing information on which of the two usage modes the terminal can support.

[0124] The terminal can receive transmission and reception beam-related instructions in an integrated TCI manner using one of the joint TCI state and separate TCI state configured by the base station. The terminal can be configured by the base station via upper layer signaling whether to use either the joint TCI state or separate TCI state.

[0125] The terminal receives transmission / reception beam-related instructions using one of the methods selected from the joint TCI state and the separate TCI state through upper layer signaling. At this time, there may be two transmission / reception beam instruction methods from the base station: a MAC-CE-based instruction method and a MAC-CE-based activation and DCI-based instruction method.

[0126] If a terminal receives a transmission / reception beam-related instruction using a joint TCI state method through upper layer signaling, the terminal can perform a transmission / reception beam application operation by receiving a MAC-CE indicating the joint TCI state from a base station, and the base station can schedule reception of a PDSCH including the MAC-CE through a PDCCH for the terminal. If the MAC-CE includes one joint TCI state, the UE can use the indicated joint TCI state to determine the uplink transmission beam or transmission filter and the downlink reception beam or reception filter starting 3 ms after transmitting a PUCCH including HARQ-ACK information indicating whether reception of the PDSCH including the MAC-CE is successful. If the MAC-CE includes two or more joint TCI states, the UE can confirm that the multiple joint TCI states indicated by the MAC-CE correspond to each code point of the TCI state field of DCI format 1_1 or 1_2 starting 3 ms after transmitting a PUCCH including HARQ-ACK information indicating whether reception of the PDSCH including the MAC-CE is successful, and activate the indicated joint TCI state. Afterwards, the UE can receive DCI format 1_1 or 1_2 and apply one joint TCI state indicated by the TCI state field in the corresponding DCI to the uplink transmission and downlink reception beams. At this time, DCI format 1_1 or 1_2 may or may not include downlink data channel scheduling information (with DL assignment) or may not include it (without DL assignment).

[0127] If a terminal receives an instruction related to a transmit / receive beam using a separate TCI state method through upper layer signaling, the terminal can perform a transmit / receive beam application operation by receiving a MAC-CE indicating a separate TCI state from a base station, and the base station can schedule reception of a PDSCH including the corresponding MAC-CE to the terminal through a PDCCH. If the MAC-CE includes only one set of separate TCI states, the terminal can determine an uplink transmit beam or transmit filter and a downlink receive beam or receive filter using the separate TCI states included in the indicated separate TCI state set starting from 3 ms after transmitting a PUCCH including HARQ-ACK information indicating whether reception of the corresponding PDSCH was successful. At this time, the separate TCI state set may mean single or multiple separate TCI states that one code point of the TCI state field in DCI format 1_1 or 1_2 can have, and one separate TCI state set may include one DL TCI state, one UL TCI state, or one DL TCI state and one UL TCI state. If there are two or more separate TCI state sets included in the MAC-CE, the UE may confirm that the multiple separate TCI state sets indicated by the MAC-CE correspond to each code point of the TCI state field of DCI format 1_1 or 1_2 starting from 3 ms after transmitting the PUCCH including HARQ-ACK information indicating whether reception for the corresponding PDSCH was successful, and may activate the indicated separate TCI state set.At this time, each code point of the TCI state field of DCI format 1_1 or 1_2 can indicate one DL TCI state, one UL TCI state, or one DL TCI state and one UL TCI state each. The terminal can receive DCI format 1_1 or 1_2 and apply a separate set of TCI states indicated by the TCI state field in the corresponding DCI to the uplink transmission and downlink reception beams. At this time, DCI format 1_1 or 1_2 may include downlink data channel scheduling information (with DL assignment) or may not include it (without DL assignment).

[0128] FIG. 5 is a diagram illustrating beam application times that may be considered when using an integrated TCI scheme in a communication system according to an embodiment of the present disclosure. As described above, a terminal may receive DCI format 1_1 or 1_2 from a base station, including (with DL assignment) or not including (without DL assignment) downlink data channel scheduling information, and apply one joint TCI state or a set of separate TCI states indicated by the TCI state field in the corresponding DCI to uplink transmission and downlink reception beams.

[0129] - DCI format 1_1 or 1_2 with DL assignment (500): If the terminal receives DCI format 1_1 or 1_2 including downlink data channel scheduling information from the base station (501) and indicates one joint TCI state or a separate TCI state set based on the integrated TCI method, the terminal receives a PDSCH scheduled based on the received DCI (505), and can transmit a PUCCH including an HARQ-ACK indicating whether reception of the DCI and the PDSCH is successful (510). At this time, the HARQ-ACK can include the meaning of whether reception of both the DCI and the PDSCH is successful, and if at least one of the DCI and the PDSCH is not received, the terminal can transmit a NACK, and if reception of both is successful, the terminal can transmit an ACK.

[0130] - DCI format 1_1 or 1_2 without DL assignment (550): If the terminal receives DCI format 1_1 or 1_2 from the base station that does not include downlink data channel scheduling information (555) and indicates one joint TCI state or a set of separate TCI states based on the integrated TCI method, the terminal may assume at least one combination of the following for the corresponding DCI.

[0131] - - Includes scrambled CRC using CS-RNTI.

[0132] - - All bits assigned to all fields used as RV (Redundancy Version) fields have a value of 1.

[0133] - - The value of all bits assigned to all fields used as MCS (Modulation and Coding Scheme) fields is 1.

[0134] - - All bits assigned to all fields used as NDI (New Data Indication) fields have values ​​of 0.

[0135] - - For FDRA (Frequency Domain Resource Allocation) Type 0, the value of all bits allocated to the FDRA field is 0, for FDRA Type 1, the value of all bits allocated to the FDRA field is 1, and when the FDRA method is dynamicSwitch, the value of all bits allocated to the FDRA field is 0.

[0136] The terminal can transmit a PUCCH including a HARQ-ACK indicating whether reception was successful for the DCI format 1_1 or 1_2 assuming the above-described matters (560).

[0137] - For both DCI format 1_1 or 1_2 with DL assignment (500) and without DL assignment (550), if a new TCI state indicated through DCI (501, 555) is the same as a TCI state that has already been indicated and applied to an uplink transmission and downlink reception beam, the UE can maintain the previously applied TCI state, and if the new TCI state is different from the previously indicated TCI state, the UE can determine the application time of a joint TCI state or a separate TCI state set that can be indicated from the TCI state field included in the DCI as the time after the first slot (520, 570) after the time equal to BAT (beam application time, 515, 565) after the PUCCH transmission (530, 580), and can use the previously indicated TCI-state until (525, 575) before the corresponding slot (520, 570).

[0138] - For both DCI format 1_1 or 1_2 with DL assignment (500) and without DL assignment (550), the BAT can be set by upper layer signaling based on terminal capability report information as a specific number of OFDM symbols, and the numerology for the BAT and the first slot after the BAT can be determined based on the smallest numerology among all cells to which the joint TCI state or separate TCI state set indicated through the DCI is applied.

[0139] A terminal can apply one joint TCI state indicated through MAC-CE or DCI to reception of control resource sets connected to all terminal-specific search spaces, reception of PDSCHs scheduled as PDCCHs transmitted from the control resource sets, transmission of PUSCHs, and transmission of all PUCCH resources.

[0140] A terminal may apply one separate TCI state set, if one separate TCI state set indicated via MAC-CE or DCI includes one DL TCI state, to reception for control resource sets connected to all terminal-specific search spaces, to reception for PDSCH scheduled as PDCCH transmitted from the control resource set, and to all PUSCH and PUCCH resources based on the previously indicated UL TCI state.

[0141] A terminal can apply a separate TCI state set indicated via MAC-CE or DCI to all PUSCH and PUCCH resources if it includes one UL TCI state, and can apply it to reception of control resource sets connected to all terminal-specific search spaces based on previously indicated DL TCI states, and to reception of PDSCH scheduled as PDCCH transmitted from the corresponding control resource set.

[0142] When a separate set of TCI states indicated via MAC-CE or DCI includes one DL TCI state and one UL TCI state, the terminal may apply the DL TCI state to reception for all control resource sets associated with the terminal-specific search space and to reception for PDSCH scheduled as PDCCH transmitted from the control resource set, and may apply the UL TCI state to all PUSCH and PUCCH resources.

[0143] [Unified TCI state MAC-CE]

[0144] Hereinafter, a single TCI state indication and activation method based on the integrated TCI scheme is described. The terminal receives a PDSCH including the following MAC-CE from the base station, and from 3 slots after transmitting a HARQ-ACK for the corresponding PDSCH to the base station, the terminal can interpret each code point of the TCI state field in DCI format 1_1 or 1_2 based on the information in the MAC-CE received from the base station. That is, the terminal can activate each entry of the MAC-CE received from the base station to each code point of the TCI state field in DCI format 1_1 or 1_2.

[0145] FIG. 6 is a diagram illustrating another MAC-CE structure for activating and indicating a joint TCI state or a separate DL or UL TCI state in a communication system according to one embodiment of the present disclosure.

[0146] - Serving Cell ID (600): This field can indicate which serving cell the MAC-CE is applied to. The length of this field can be 5 bits. If the serving cell indicated by this field is included in one or more of the upper layer signaling simultaneousU-TCI-UpdateList1, simultaneousU-TCI-UpdateList2, simultaneousU-TCI-UpdateList3, or simultaneousU-TCI-UpdateList4, the MAC-CE can be applied to all serving cells included in one or more of the lists simultaneousU-TCI-UpdateList1, simultaneousU-TCI-UpdateList2, simultaneousU-TCI-UpdateList3, or simultaneousU-TCI-UpdateList4 that include the serving cell indicated by this field.

[0147] - DL BWP ID (605): This field can indicate to which DL BWP the corresponding MAC-CE applies, and the meaning of each code point in this field can correspond to each code point of the bandwidth part indicator in the DCI. The length of this field can be 2 bits.

[0148] - UL BWP ID (610): This field can indicate which UL BWP the corresponding MAC-CE applies to, and the meaning of each code point in this field can correspond to each code point of the bandwidth part indicator in the DCI. The length of this field can be 2 bits.

[0149] - Pi (615): This field can indicate whether each code point in the TCI state field in DCI format 1_1 or 1_2 has multiple TCI states or a single TCI state. If the value of Pi is 1, it means that the corresponding ith code point has multiple TCI states, which may mean that the corresponding code point may include a separate DL TCI state and a separate UL TCI state. If the value of Pi is 0, it means that the corresponding ith code point has a single TCI state, which may mean that the corresponding code point may include either a joint TCI state, a separate DCI TCI state, or a separate UL TCI state.

[0150] - D / U (620): This field can indicate whether the TCI state ID field in the same octet is a joint TCI state, a separate DL TCI state, or a separate UL TCI state. If this field is 1, the TCI state ID field in the same octet can be a joint TCI state or a separate DL TCI state, and if this field is 0, the TCI state ID field in the same octet can be a separate UL TCI state.

[0151] - TCI state ID (625): This field can indicate a TCI state that can be identified by the upper layer signaling TCI-StateId. If the D / U field is set to 1, this field can be used to express the TCI-StateId, which can be expressed in 7 bits. If the D / U field is set to 0, the MSB (most significant bit) of this field can be considered a reserved bit, and the remaining 6 bits can be used to express the upper layer signaling UL-TCIState-Id. The maximum number of TCI states that can be activated can be 8 for a joint TCI state and 16 for separate DL or UL TCI states.

[0152] - R: Indicates reserved bit and can be set to 0.

[0153] For the MAC-CE structure of FIG. 6 described above, the terminal can include the third octet including the P1, P2, ..., P8 fields in FIG. 6 in the MAC-CE structure, regardless of whether unifiedTCI-StateType-r17 in MIMOparam-r17 in ServingCellConfig, which is an upper layer signaling, is set to joint or separate. In this case, the terminal can perform TCI state activation using the fixed MAC-CE structure regardless of the upper layer signaling set by the base station. As another example, for the MAC-CE structure of FIG. 6 described above, the terminal can omit the third octet including the P1, P2, ..., P8 fields in FIG. 6 when unifiedTCI-StateType-r17 in MIMOparam-r17 in ServingCellConfig, which is an upper layer signaling, is set to joint. In this case, the terminal can save up to 8 bits of the payload of the corresponding MAC-CE according to the upper layer signaling set by the base station. In addition, all D / U fields located from the fourth octet to the first bit in Fig. 6 can be regarded as R fields, and all corresponding R fields can be set to 0 bits.

[0154] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. Hereinafter, a base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, a gNB, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a wireless access point, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. Although embodiments of the present disclosure are described below using a 5G system as an example, embodiments of the present disclosure may also be applied to other communication systems having a similar technical background or channel type. For example, this may include LTE or LTE-A mobile communication and mobile communication technologies developed after 5G. Therefore, embodiments of the present disclosure may be applied to other communication systems with some modifications without significantly departing from the scope of the present disclosure as determined by a person skilled in the art. The contents of this disclosure can be applied to FDD (frequency division duplex), TDD (time division duplex), XDD (cross division duplex) systems, etc.

[0155] Additionally, when describing the present disclosure, detailed descriptions of related functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Furthermore, the terms described below are defined based on the functions of the present disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the contents of this specification.

[0156] In the following description of the present disclosure, upper layer signaling may be signaling corresponding to at least one or a combination of one or more of the following signaling.

[0157] - MIB (Master Information Block)

[0158] - SIB (System Information Block) or SIB

[0159] - RRC (Radio Resource Control)

[0160] - MAC (Medium Access Control) CE (Control Element)

[0161] In addition, L1 signaling may be signaling corresponding to at least one or a combination of one or more signaling methods using the following physical layer channels or signaling.

[0162] - PDCCH (Physical Downlink Control Channel)

[0163] - DCI (Downlink Control Information)

[0164] - UE-specific DCI

[0165] - Group common DCI

[0166] - Common DCI

[0167] - Scheduling DCI (e.g. DCI used for scheduling downlink or uplink data)

[0168] - Non-scheduled DCI (e.g. DCI not intended for scheduling downlink or uplink data)

[0169] - PUCCH (Physical Uplink Control Channel)

[0170] - UCI (Uplink Control Information)

[0171] In the present disclosure below, the above examples are described through a number of embodiments, but they are not independent and one or more embodiments may be applied simultaneously or in combination.

[0172] Existing beam measurement and setting techniques assume that each node or terminal performing communication selects one of the preset analog beams to perform communication.

[0173] FIG. 7 is a diagram illustrating an example of sub-array-based analog beamforming and digital beamforming mixing in a communication system to which the present disclosure can be applied.

[0174] For example, for a terminal or node performing communications in the FR2 region, a complete antenna array can be implemented through a combination of sub-arrays. Beamforming can be implemented between antenna elements implementing each sub-array by performing analog beamforming through carrier phase shift without supporting digital beamforming.

[0175] Digital beamforming, or digital precoding, can be implemented by performing signal processing between each sub-array. After digital precoding, the input signal is repeated (or duplication), and the input signal can be copied according to repetition (or duplication) to generate multiple identical output signals. Multiple identical output signals can have different phases through phase modulation. By adopting the above structure, only a small number of antenna ports can be supported compared to the number of antenna elements constituting the array. Furthermore, since the beam of each sub-array is determined by selecting one of a limited number of preset analog beams, the beamforming resolution that can be supported by the entire array is reduced. The reduced beamforming resolution also reduces the maximum beamforming gain that can be supported.

[0176] In order to select an appropriate analog beam in a communication system where the application of an analog beam is essential as described above, the transmitter sets a reference signal for beam measurement of the receiver for each preset analog beam and performs transmission. That is, the transmitter sets and transmits a number of reference signals for beam measurement equal to or greater than the number of preset analog beams. When setting and transmitting the above reference signals, the transmitter may default to not simultaneously transmit reference signals corresponding to different beams of the transmitter. According to the above operation, the receiver can perform measurement on one candidate analog beam each time it receives a reference signal for beam measurement.

[0177] FIG. 8 is a diagram illustrating an example of an analog beam setting method that can be supported in a communication system to which the present disclosure can be applied.

[0178] Referring to Fig. 8, an analog beam setting is illustrated with a 3dB beam width as the beam setting resolution to generate a beam that exhibits a degradation of 3dB or less compared to the maximum beamforming gain that can be supported by the antenna when setting each candidate beam. In general, as the antenna array increases in size, the 3dB beam width may narrow rapidly, and thus the number of candidate beams required may also increase rapidly.

[0179] The technique of performing beam measurement and selection through analog beam sweeping at the transmitter has the advantage of allowing the receiver, e.g., a terminal, to select the optimal beam through a simple operation of comparing the reception power or reception performance (or (reception) quality) of reference signals corresponding to each beam, e.g., RSRP (reference signal received power), RSRQ (reference signal received quality), SINR (signal to interference plus noise ratio), or SNR (signal to noise ratio), and is therefore widely used in current communication systems.

[0180] In addition, when transmitting a reference signal for each antenna element without analog beamforming at the transmitter, the reference signal reception power is too low to allow the receiver to estimate beam information or channel information. As a solution to this problem, it is common to transmit the beam reference signal through analog beamforming. In other words, the above technique using a limited analog beam has the advantage of simplifying the operation of the receiver while increasing the beam measurement accuracy of the receiver.

[0181] However, as explained above, there is a disadvantage that only a limited number of analog beams can be supported, or that increasing the resolution of the analog beam significantly increases the RS overhead and measurement overhead required for beam measurement. In other words, there is a disadvantage that there is a limit to the beam control accuracy or high precision (resolution) that can be realistically supported. As described above, the process of finding the optimal receiver beam for each candidate beam provided by the transmitter by going through the beam sweeping procedure at both the transmitter and receiver is called beam sweeping.

[0182] FIG. 9 is a diagram illustrating an example of a beam sweeping procedure for beam pairing in a communication system to which the present disclosure can be applied.

[0183] Referring to Fig. 9, a base station is exemplified as a transmitting end and a terminal is exemplified as a receiving end, but the opposite case is also possible. The base station and the terminal can perform beam sweeping for a transmitting beam and a receiving beam, respectively, for a certain time interval. That is, beam sweeping includes Tx beam sweeping for a transmitting beam (Tx beam) and Rx beam sweeping for a receiving beam (Rx beam), and a candidate Rx beam corresponding to a candidate Tx beam can be detected, which can be called a beam pair.

[0184] FIG. 10 is a diagram illustrating an example of a beam pair-based terminal beam modification procedure in a communication system to which the present disclosure can be applied.

[0185] After the beam pair is set as described above, the base station can perform beam control using the beam pair for each of the downlink and / or uplink. For example, when a beam change is required, the base station can transmit information about a new beam to be used to the terminal in the form of a base station beam index. The terminal that receives the beam index applies the terminal beam corresponding to the beam index, i.e., the beam pair, to perform conversion to a new beam. In the present disclosure, the existing beam of the base station may mean that the base station maintains the beam that has been used without changing / converting the beam, and the new beam of the base station may mean that the base station performs a change / conversion of the beam.

[0186] The base station can transmit a beam index to the terminal through the PDCCH (physical downlink control channel) (and / or DCI (downlink control information) included in the PDCCH), and the terminal can receive it. The terminal can check the beam index from the PDCCH (and / or DCI included in the PDCCH) and transmit an ACK (acknowledgement) therefor through the PUCCH (physical uplink control channel), and the base station can receive it. Afterwards (for example, after the BAT (beam application time) from the PUCCH transmission time), the base station and the terminal can perform transmission and reception of the PDCCH, PDSCH (physical downlink shared channel), PUCCH, and / or PUSCH (physical uplink shared channel) by applying a beam pair corresponding to the beam index. That is, the base station can switch to a beam corresponding to the beam index (i.e., an indicated beam), and the terminal can switch to a beam corresponding to the beam index (i.e., an indicated It can be switched to an aligned beam (beam).

[0187] FIG. 11 is a diagram illustrating an example of terminal reception beam configuration in a communication system to which the present disclosure can be applied. FIG. 11 illustrates an example of an operation in which a reception beam is preset and the terminal then performs beam-based reception.

[0188] The above beam changing method has the advantage of simplifying the beam-based reception operation of the terminal after beam selection, since it is a method in which the terminal selects the beam to be used for communication in advance based on instructions from the base station. That is, the terminal can only consider reception for beams whose use has been predetermined and instructed. In Fig. 11, a reception operation can be performed so as to correspond to the beam that the terminal will use for receiving a downlink signal and / or channel. For example, a phase conversion value for each reception antenna can be predetermined, and only the signal received through the phase conversion reception, that is, the reception beam, is stored in a buffer and then a subsequent receiver demodulation operation is performed. For example, the reception beam can correspond to a synthesis of an original reference signal or channel and a reference signal or channel whose phase has been shifted by θ1 with respect to the original reference signal or channel. Alternatively, the reception beam can correspond to a synthesis of an original reference signal or channel and a reference signal or channel whose phase has been shifted by θ2 with respect to the original reference signal or channel. That is, since the phase conversion value is predetermined for each receiving antenna, phase conversion is applied to the signal received for each receiving antenna, and the phase-converted signal for each receiving antenna can be stored in a buffer. Demodulation can be performed based on the signal stored in the buffer.

[0189] The method of pre-configuring the beam to be used by the terminal for each candidate beam of the base station based on beam pairing has the advantage of simplifying the beam control procedure and terminal beam application operation, but has the disadvantage of requiring periodic beam pair modification. In particular, when performing communication in an environment where the channel condition changes rapidly, the beam pair update operation must be performed frequently. Referring again to Fig. 6, the beam sweeping operation for beam pairing must use a lot of radio resources. Therefore, frequent beam pair updates can reduce communication efficiency. Furthermore, if the beam sweeping operation is not performed sufficiently frequently, the beam gain may decrease, and in severe cases, it may cause beam failure.

[0190] Accordingly, the present disclosure proposes a method and device for modifying a beam of a terminal without beam pairing and / or beam pair update operations. The present disclosure proposes a method and device for fast terminal beam conversion.

[0191] FIG. 12 is a diagram illustrating an example of a terminal beam change procedure before data transmission and reception according to one embodiment of the present disclosure.

[0192] The terminal can perform terminal beam modification based on the beam transformation reference signal before data transmission and reception. For example, the terminal can perform terminal beam modification by receiving the beam transformation reference signal before PDSCH reception or PUSCH transmission. The terminal beam modification operation may take a certain amount of time. The terminal can then perform data transmission or reception by applying the modified beam. When the beam transformation reference signal is received, the terminal can search for a beam to be used for subsequent data transmission and reception through the beam transformation reference signal without setting a reception beam in advance. On the other hand, the terminal can perform a task of receiving or transmitting data according to a beam that has already been set for data transmission and reception (i.e., a beam to be used for the searched data transmission and reception).

[0193] Specifically, referring to FIG. 12, the terminal can receive a beam conversion reference signal through two antenna elements. The number of antenna elements is an example and is not limited thereto. The beam conversion reference signal and / or information based on the beam conversion reference signal are stored in a buffer, and the terminal can perform beam selection based on the stored information. Each antenna element can be connected to each buffer (or each antenna element can correspond to each buffer), and information about the beam conversion reference signal received from each antenna element is stored in a buffer corresponding to the corresponding antenna element. Here, the time from when the terminal receives the beam conversion reference signal to the time when the beam is selected according to the beam selection may correspond to a certain time (T1) required for the above-described beam modification work. That is, T1 may be a processing time for buffering and scanning (beam scanning, beam selection), or at least include the processing time. The terminal may be able to transmit and receive data based on the beam (new beam) selected after the time T1+BAT, the time when T1 and BAT are combined. That is, the terminal cannot apply a new beam during the time period of T1+BAT, and the time at which data transmission and reception is performed may have to be after T1+BAT. That is, the time period during which the new beam is not applied may have to be longer than T1+BAT. In the above, BAT (Beam Application Time) means the time it takes for the terminal to change the receiving beam or transmitting beam.

[0194] FIG. 13 is a diagram illustrating an example of a terminal operation for rapid terminal beam modification according to one embodiment of the present disclosure. FIG. 13 may be understood as an example of a method for receiving a beam conversion reference signal of a terminal according to the operation of FIG. 10.

[0195] Referring to FIG. 13, the terminal can distinguish and store reference signals (or information based on reference signals) for each receiving antenna or each receiving port in a buffer. That is, reference signals (or information based on reference signals) are distinguished and stored in the buffer of the terminal based on the receiving antenna or receiving port. The terminal can search for an optimal combination of reference signals for each receiving antenna or receiving port. For example, the optimal combination can be performed based on various parameters representing link quality, such as when RSRP is maximized after combination, when RSRQ is maximized after combination, when SINR is maximized after combination, and when SNR is maximized after combination. That is, the terminal can search for an optimal combination of reference signals so that the combined signal quality or quality is maximized. The beam corresponding to the optimal combination of reference signals can be a new beam according to the beam selection described above. For example, the terminal can use a method of applying a phase difference between received signals when performing the above combination.

[0196] The terminal beam determined through the above search can be defined as a terminal spatial rx filter, and when the beam is used for upward transmission (uplink transmission), the beam can be defined as a spatial tx filter, and can also be defined as a spatial filter. That is, the terminal reception beam determined through the search can be understood as a spatial RX filter, and the terminal transmission beam determined through the search can be understood as a spatial TX filter. Alternatively, it can be understood as a TCI state (or TCI-UL state).

[0197] When the terminal reports the above-determined terminal beam to the base station, the report may follow a format such as spatial filter reporting, spatial tx filter reporting, or spatial rx filter reporting. That is, the terminal may report the determined beam based on one or more of spatial filter reporting, spatial tx filter reporting, or spatial rx filter reporting.

[0198] Additionally, the above terminal beam information may be performed as an element of CSI reporting in a more general case. And / or may be performed in the form of TCI state reporting, which is a beam control method. And / or the terminal may not report to the base station the results of the terminal beam determined by the above beam search.

[0199] The data reception operation performed after the terminal completes the beam search used for communication can be performed in a manner in which the terminal performs data reception through the terminal beam determined through the search, as illustrated in Fig. 11. Conversely, the data transmission operation performed after the terminal completes the beam search used for communication can also be performed in a manner in which the terminal performs data transmission through the terminal beam determined through the search.

[0200] FIG. 14 is a diagram illustrating an example of a front-loaded BMRS according to one embodiment of the present disclosure.

[0201] FIG. 15 is a diagram illustrating an example of a front-loaded BMRS according to one embodiment of the present disclosure.

[0202] FIG. 14 and FIG. 15 may be understood as examples of a slot structure configured by applying an embodiment according to FIG. 12 and FIG. 13. That is, referring to FIG. 14 or FIG. 15, a PDCCH, a BM-RS (beam management reference signal), and a PXSCH (e.g., PDSCH or PUSCH) may be included / mapped within one slot. The BM-RS may be understood as the beam transformation reference signal described above.

[0203] Front-loaded BMRS may mean that the terminal receives the BM-RS before transmitting or receiving data transmitted or received by the control information after receiving the control information. In other words, the front-loaded BMRS may be a BMRS that the terminal receives after receiving the DCI but before transmitting or receiving data scheduled by the DCI. The reception of the front-loaded BMRS may be controlled by control information that controls the transmission and reception of the related data.

[0204] For example, as shown in FIG. 14, a base station can instruct reception of front-loaded BMRS and transmission / reception of data simultaneously through one control information and / or one PDCCH transmission, and in this case, a terminal can determine a terminal beam to be applied to data transmitted / received by the instruction through the front-loaded BMRS received by the instruction.

[0205] Control information (PDCCH, DCI) for scheduling data transmission and reception can trigger front-loaded BMRS transmission. In this case, a terminal receiving the control information can expect front-loaded BMRS. For example, a base station can configure a terminal to use front-loaded BMRS through upper layer signaling, and the terminal that has received the configuration can expect front-loaded BMRS when it receives control information for scheduling data transmission and reception. When front-loaded BMRS is transmitted, the terminal can perform terminal beam modification operation based on the reference signal.

[0206] A time offset may be required for beam modification at a terminal. The terminal transmits or receives data after the time offset T1 and BAT (T1+BAT). The modified beam may be applied to data transmissions or receptions performed after the time offset (or T1+BAT).

[0207] The complexity of the terminal's beam search operation and the time required for beam search may vary depending on the number of terminal candidate beams that the terminal must search. In other words, the time offset required for the terminal's beam modification operation may vary depending on the number of terminal candidate beams, etc.

[0208] For example, if terminal beam search is performed while the base station beam remains unchanged, as in FIG. 14, the terminal can expect a small change compared to the previously used terminal beam, and thus performs beam search targeting a small number of terminal candidate beams. Therefore, the terminal beam modification task can be completed in a relatively short time, which means that a small time offset can be applied.

[0209] On the other hand, when a base station beam changed as in Fig. 15 is applied to a beam conversion reference signal, the terminal must perform terminal beam search targeting a larger number of candidate beams, which means that a larger time offset T2 (or T2+BAT) must be applied between reception of the beam conversion reference signal and data transmission / reception. In other words, this means that a large time offset can be applied.

[0210] That is, the time offset applied in the case of Fig. 14 may be relatively smaller than the time offset applied in the case of Fig. 15. The time offset applied in the case of Fig. 15 may be relatively larger than the time offset applied in the case of Fig. 14. That is, T1 <T2 일 수 있다. 즉, 기지국은 상기 front-loaded BMRS의 사용 방식 또는 전송 목적에 따라 단말이 다른 크기의 time offset을 빔 탐색 및 변경에 적용하도록 단말에 지시할 수 있다.

[0211] In addition, in order to avoid a case where the time offset above becomes too large and both the front-loaded BMRS and PxSCH cannot be mapped within a single slot, the beam search operation of the terminal may be restricted. For example, if the maximum number of search beams on which the terminal can perform beam search and PxSCH transmission / reception within a single slot is 4, the base station may restrict the beam search operation of the terminal to perform search operations only for the 4 beams, or may transmit additional information for the restriction, such as the number of search beams and specific information on search candidate beams, to the terminal before the terminal receives the front-BMRS. And / or, if it is impossible to perform transmission / reception of the front-loaded BMRS and the PxSCH controlled by the control information instructing transmission of the front-loaded BMRS within a single slot due to the use of a large time offset value, the base station may set the time offset value between the reception of control information and the transmission / reception of the PxSCH to a value larger than one slot and notify the terminal of this.

[0212] In applying the front-loaded BMRS according to one embodiment of the present disclosure, the time offset between BMRS reception and data transmission / reception may be set to different values ​​or defined by the following elements. That is, the time offset between BMRS reception and data transmission / reception may be determined / identified based on one or more of the following parameters / information / elements.

[0213] - the time it takes for a terminal to search for one terminal candidate beam, and / or

[0214] - The time required for a terminal to perform beam switching between terminal candidate beams, and / or

[0215] - The number of terminal candidate beams that a terminal can search within a given time, for example, within one symbol period. The given time may be determined / set as a value such as a symbol period, a slot period, or a combination thereof.

[0216] - A factor that determines the number of terminal candidate beams for which the terminal must perform a search, and / or the number of terminal candidate beams for which the terminal must perform a search. For example:

[0217] - - Whether a new base station beam is applied to the front-loaded BMRS (for this, refer to the description of an embodiment described in FIGS. 14 and 15), and / or

[0218] - - Whether a large angular scale beam search is instructed for the front-loaded BMRS. The terminal may be preset with information on the terminal's beam search method corresponding to the small angular scale and the large angular scale. For example, the terminal may be instructed to perform a beam search by considering four or fewer candidate beams as a small angular scale operation, and to perform a beam search by considering four or more candidate beams as a large angular scale operation. The numbers are examples and the present disclosure is not limited thereto. Alternatively, an operation of searching a terminal beam corresponding to one base station beam, for example, an operation of finding a terminal beam corresponding to one SSB beam, may be defined as a small angular scale operation, and an operation of finding a terminal beam corresponding to two or more base station beams, for example, two or more SSB beams, may be defined as a large angular scale operation.

[0219] A method for performing front-loaded BMRS-based fast terminal beam conversion according to one embodiment of the present disclosure may be performed based on one or more of the following operations and / or combinations thereof.

[0220] - The terminal can report information related to the processing time required to perform the corresponding operation. For example, this can be reported to the base station as UE capability information.

[0221] - The base station can notify / transmit to the terminal information related to the complexity of the beam search operation that the terminal must perform when receiving the corresponding BMRS (or information related to the beam search) for each front-loaded BMRS.

[0222] - For example, when a base station performs front-loaded BMRS triggering via PDCCH, it can transmit information to the terminal regarding whether the BMRS is transmitted via the base station's existing beam or a new beam. The information transmitted to the terminal can be transmitted to the terminal in the following manner, for example.

[0223] - - -1) The base station can pre-allocate / configure multiple front-BMRS resources to the terminal.

[0224] - - -2) The base station can set in advance or notify the terminal whether to apply a new base station beam for each resource.

[0225] - - -3) The base station can notify the terminal of whether a new beam is applied by indicating a resource at the stage of triggering the front-loaded BMRS. For example, the base station can set multiple front-BMRS resources by higher layer signaling (e.g., RRC, MAC-CE, etc.). In addition, the base station can indicate for each front-BMRS resource whether a new base station beam is applied (or whether an existing base station beam is applied). For example, it can be indicated by a bitmap or a codepoint. In addition, the base station can indicate a specific front-BMRS resource among multiple front-BMRS resources based on the PDCCH, and the terminal can identify whether a new base station beam corresponding to the indicated front-BMRS resource is applied (or whether an existing base station beam is applied). That is, the PDCCH that triggers the front-BMRS resource may include information indicating a specific front-BMRS resource among multiple front-BMRS resources.

[0226] - - And / or, the base station may transmit to the terminal whether to apply a new beam through a separate indicator. For example, the separate indicator may be transmitted through upper layer signaling and / or L1 signaling.

[0227] - - And / or, a method may be used in which the base station sets in advance whether to apply a new beam for each terminal, each wireless resource, and / or each reference signal resource.

[0228] - - Information about various factors that affect the complexity of the beam search operation of the terminal can be notified to the terminal.

[0229] According to one embodiment of the present disclosure, in determining whether to transmit and / or use Front-BMRS, one or more or a combination of one or more of the following methods may be used.

[0230] - 1) The base station can configure whether to use front-loaded BMRS to the terminal. For example, this can be configured through RRC configuration (or higher layer signaling). If the use of front-loaded BMRS is configured as described above,

[0231] - - A) The terminal can assume that front-loaded BMRS is always transmitted when data transmission and reception is scheduled and / or configured.

[0232] - - B) And / or, if multiple front-loaded BMRS resources or transmissions are configured, the terminal may be separately instructed to activate some of them. The activation may be transmitted, for example, via MAC CE. In this case, the base station may configure different terminal actions for each BMRS resource or transmission.

[0233] - - - i. The terminal can assume that the activated front-loaded BMRS is transmitted before data transmission or reception.

[0234] - - - ii. And / or, the terminal may assume that the configured or activated front-loaded BMRS is separately instructed whether to transmit control information, for example, via PDCCH.

[0235] Specifically, activation for front-loaded BMRS resources can be based on RRC and MAC CE, or based on RRC, MAC CE, and DCI.

[0236] For example, a base station can configure multiple front-BMRS resources via RRC signaling. Additionally, the base station can use MAC-CE to indicate the activation of at least some of the multiple front-BMRS resources. A terminal can expect to receive BMRS signals from the activated front-BMRS resources.

[0237] As another example, a base station can configure multiple front-BMRS resources via RRC signaling. Furthermore, the base station can indicate the activation of at least some of the multiple front-BMRS resources via MAC-CE. Furthermore, the base station can indicate any one of the activated front-BMRS resources via DCI, and the UE can expect to receive BMRS from the front-BMRS resource indicated by the DCI.

[0238] In another embodiment, the base station may notify the terminal of the transmission of the front-loaded BMRS as a method for beam measurement and reporting. In this case, the terminal may modify the terminal beam through the front-loaded BMRS. Furthermore, the terminal may report the measurement results for the modified base station beam to the base station. For example, the information or report contents reported to the base station may include information on beam performance and / or link quality, and / or information on beam control, such as a request for use of a new beam.

[0239] For example, if a base station uses a front-loaded BMRS for beam measurement and reporting, the RS can be used without instructions for data transmission and reception. That is, if the base station transmits / configures a front-loaded BMRS to a terminal to request reporting of the above-described information, the PDCCH for data scheduling can be omitted. The base station can configure the purpose of the front-loaded BMRS in higher-layer signaling.

[0240] FIG. 16 is a diagram illustrating an example of terminal operation according to one embodiment of the present disclosure. Various modifications may be made to the method illustrated in the flowchart of FIG. 16. For example, although illustrated as a series of steps, the various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.

[0241] Referring to FIG. 16, in operation 1610 according to one embodiment, a terminal may receive BMRS configuration information. For example, the BMRS configuration information may include, but is not limited to, information on whether front-loaded BMRS is applied.

[0242] In operation 1620 according to one embodiment, a terminal may receive a PDCCH. The PDCCH may include scheduling information for a PDSCH to be received by the terminal or scheduling information for a PUSCH to be transmitted by the terminal. If BMRS configuration information is set, the PDCCH may be interpreted as a trigger for BMRS. That is, a terminal that receives a PDCCH may expect reception of BMRS.

[0243] In operation 1630 according to one embodiment, the terminal may receive BMRS. Reception of BMRS may be performed based on one or more of BMRS configuration information or PDCCH.

[0244] In operation 1640 according to one embodiment, the terminal can perform data communication. The data communication can correspond to the PDCCH. For example, if the PDSCH is scheduled by the PDCCH, the terminal can receive the PDSCH, and if the PUSCH is scheduled by the PDCCH, the terminal can transmit the PUSCH. The transmission and reception beams of the terminal can be identified based on the BMRS.

[0245] For more specific details on the operation of the terminal illustrated in Fig. 16, refer to the description of the above-described embodiment.

[0246] FIG. 17 is a diagram illustrating an example of base station operation according to one embodiment of the present disclosure. Various modifications may be made to the method illustrated in the flowchart of FIG. 17. For example, although illustrated as a series of steps, the various steps in each diagram may overlap, occur in parallel, occur in different orders, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.

[0247] Referring to FIG. 17, in operation 1710 according to one embodiment, the base station may transmit BMRS configuration information. For example, the BMRS configuration information may include, but is not limited to, information on whether front-loaded BMRS is applied.

[0248] In operation 1720 according to one embodiment, the base station may transmit a PDCCH. The PDCCH may include scheduling information for a PDSCH to be received by the terminal or scheduling information for a PUSCH to be transmitted by the terminal. If BMRS configuration information is transmitted, the PDCCH may be interpreted as triggering for the BMRS. That is, the base station that transmitted the PDCCH may transmit the BMRS.

[0249] In operation 1730 according to one embodiment, the base station may transmit a BMRS. The transmission for the BMRS may be related to one or more of BMRS configuration information or a PDCCH.

[0250] In operation 1740 according to one embodiment, the base station can perform data communication. The data communication can correspond to the PDCCH. For example, if the PDSCH is scheduled by the PDCCH, the base station can transmit the PDSCH, and if the PUSCH is scheduled by the PDCCH, the base station can receive the PUSCH. Here, the transmission / reception beam used by the terminal can be related to the BMRS.

[0251] For more specific details on the operation of the terminal illustrated in Fig. 17, refer to the description of the above-described embodiment.

[0252] FIG. 18 is a diagram illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0253] Referring to FIG. 18, the terminal may include a transceiver, which refers to a terminal receiving unit (1800) and a terminal transmitting unit (1810), a memory (not shown), and a terminal processing unit (1805, or a terminal control unit or processor). Depending on the communication method of the terminal described above, the transceiver units (1800, 1810), the memory, and the terminal processing unit (1805) of the terminal may operate. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more or fewer components than the components described above. In addition, the transceiver unit, the memory, and the processor may be implemented in the form of a single chip.

[0254] A transceiver unit can transmit and receive signals to and from a base station. The signals may include control information and data. To this end, the transceiver unit may include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. However, this is merely one embodiment of the transceiver unit, and the components of the transceiver unit are not limited to the RF transmitter and RF receiver.

[0255] Additionally, the transceiver can receive a signal through a wireless channel and output it to the processor, and transmit a signal output from the processor through the wireless channel.

[0256] Memory can store programs and data necessary for the terminal's operation. Furthermore, memory can store control information or data included in signals transmitted and received by the terminal. Memory can be comprised of a storage medium, such as ROM, RAM, a hard disk, CD-ROM, or DVD, or a combination of such storage media. Furthermore, there can be multiple memories.

[0257] Additionally, the processor can control a series of processes to enable the terminal to operate according to the aforementioned embodiments. For example, the processor can receive DCI consisting of two layers and control components of the terminal to simultaneously receive multiple PDSCHs. There may be multiple processors, and the processors can perform component control operations of the terminal by executing programs stored in memory.

[0258] FIG. 19 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0259] Referring to FIG. 19, the base station may include a transceiver, which refers to a base station receiver (1900) and a base station transmitter (1910), a memory (not shown), and a base station processor (1905, or a base station control unit or processor). Depending on the communication method of the base station described above, the transceiver (1900, 1910), the memory, and the base station processor (1905) of the base station may operate. However, the components of the base station are not limited to the examples described above. For example, the base station may include more or fewer components than the components described above. In addition, the transceiver, the memory, and the processor may be implemented in the form of a single chip.

[0260] The transceiver can transmit and receive signals with the terminal. Here, the signals may include control information and data. To this end, the transceiver may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. However, this is only one embodiment of the transceiver, and the components of the transceiver are not limited to the RF transmitter and RF receiver.

[0261] Additionally, the transceiver can receive a signal through a wireless channel and output it to the processor, and transmit the signal output from the processor through the wireless channel.

[0262] The memory can store programs and data necessary for the operation of the base station. Furthermore, the memory can store control information or data included in signals transmitted and received by the base station. The memory can be comprised of a storage medium, such as ROM, RAM, a hard disk, CD-ROM, or DVD, or a combination of such storage media. Furthermore, there can be multiple memories.

[0263] The processor can control a series of processes to enable the base station to operate according to the aforementioned embodiments of the present disclosure. For example, the processor can configure two layers of DCIs containing allocation information for multiple PDSCHs and control each component of the base station to transmit them. There may be multiple processors, and the processors can perform component control operations of the base station by executing programs stored in memory.

[0264] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0265] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

[0266] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0267] Additionally, the program may be stored on an attachable storage device that is accessible via a communication network, such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device implementing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device implementing an embodiment of the present disclosure.

[0268] In the specific embodiments of the present disclosure described above, components included in the embodiments are expressed singularly or plurally, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0269] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples to easily explain the technical contents of the present disclosure and help understand the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it will be apparent to those skilled in the art to which the present disclosure pertains that other modified embodiments based on the technical idea of ​​the present disclosure are possible. In addition, the above-described embodiments can be combined and operated with each other as needed. For example, parts of one embodiment of the present disclosure and another embodiment can be combined with each other to operate a base station and a terminal. For example, parts of the first embodiment and the second embodiment of the present disclosure can be combined with each other to operate a base station and a terminal.

[0270] Meanwhile, the order of description in the drawings explaining the method of the present disclosure does not necessarily correspond to the order of execution, and the order of precedence may be changed or executed in parallel.

[0271] Alternatively, the drawings illustrating the method of the present disclosure may omit some components and include only some components without detracting from the essence of the present disclosure.

[0272] In addition, the method of the present disclosure may be implemented by combining some or all of the contents included in each embodiment within a scope that does not harm the essence.

[0273] Various embodiments of the present disclosure have been described above. The foregoing description of the present disclosure is for illustrative purposes only, and the embodiments of the present disclosure are not limited to the disclosed embodiments. Those skilled in the art will appreciate that the present disclosure can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present disclosure. The scope of the present disclosure is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present disclosure.

Claims

1. In a method performed by a terminal in a communication system, A step of receiving configuration information for DL ​​RS (downlink reference signal) related to BM (beam management) through upper layer signaling; A step of receiving DCI (downlink control information) for scheduling a data channel based on a PDCCH (physical downlink control channel) of a first terminal beam, the DCI including information related to triggering the DL RS; A step of receiving the DL RS based on the above setting information and the DCI; A step of identifying a second terminal beam different from the first terminal beam based on the DL RS; and A method comprising the step of performing communication for the data channel based on the second terminal beam.

2. In paragraph 1, The above DL RS is received in at least some of the symbols between the last symbol of the PDCCH and before the first symbol of the data channel, A method wherein the symbols are related to a time required for the terminal to identify the second terminal beam based on the DL RS and apply it to communication of the data channel, and the time required for the terminal is reported as terminal capability.

3. In paragraph 1, If the base station beam is identified as changed based on the above DCI, the DL RS is received based on the second terminal beam, A method wherein, if it is identified that the base station beam has not been changed based on the DCI, the DL RS is received based on the first terminal beam.

4. In paragraph 3, If the beam of the base station is identified as changed based on the DCI, the second terminal beam is identified among the first terminal candidate beams, and the symbols between the last symbol of the PDCCH and the first symbol of the data channel are based on the first time offset, If it is identified that the beam of the base station is not changed based on the DCI, the symbols between the last symbol of the PDCCH and the first symbol of the data channel are based on the second time offset, A method wherein the number of the first terminal candidate beams is greater than the number of the second terminal candidate beams, and the first time offset is greater than the second time offset.

5. In paragraph 1, The above DL RS is received based on a plurality of antenna elements of the terminal, the plurality of antenna elements correspond to a plurality of buffers, and information corresponding to the DL RS received from each antenna element is stored in each buffer corresponding to each antenna element. A method in which the terminal beam is identified based on information stored in the plurality of buffers.

6. In paragraph 1, The above configuration information includes information about multiple DL RS resources, A method wherein the above DL RS is received from an activated DL RS resource among the plurality of DL RS resources, and information about the activated DL RS resource is received through a MAC CE (medium access control control element).

7. At the terminal of the communication system, Transmitter and receiver; and A processor coupled to the transceiver, the processor comprising: Receive configuration information for DL ​​RS (downlink reference signal) related to BM (beam management) through upper layer signaling; Receive DCI (downlink control information) for scheduling a data channel based on a PDCCH (physical downlink control channel) of a first terminal beam, the DCI including information related to triggering the DL RS; Receive the DL RS based on the above setting information and the DCI; Identifying a second terminal beam different from the first terminal beam based on the above DL RS; and A terminal configured to perform communication for the data channel based on the second terminal beam.

8. In paragraph 7, The above DL RS is received in at least some of the symbols between the last symbol of the PDCCH and before the first symbol of the data channel, The above symbols are related to the time required for the terminal to identify the second terminal beam based on the DL RS and apply it to communication of the data channel, and the time required for the terminal is reported as terminal capability.

9. In paragraph 7, If the base station beam is identified as changed based on the above DCI, the DL RS is received based on the second terminal beam, A terminal, wherein the DL RS is received based on the first terminal beam, if it is identified that the base station beam has not been changed based on the DCI.

10. In paragraph 9, If the beam of the base station is identified as changed based on the DCI, the second terminal beam is identified among the first terminal candidate beams, and the symbols between the last symbol of the PDCCH and the first symbol of the data channel are based on the first time offset, If it is identified that the beam of the base station is not changed based on the DCI, the symbols between the last symbol of the PDCCH and the first symbol of the data channel are based on the second time offset, A terminal wherein the number of the first terminal candidate beams is greater than the number of the second terminal candidate beams, and the first time offset is greater than the second time offset.

11. In paragraph 7, The above DL RS is received based on a plurality of antenna elements of the terminal, the plurality of antenna elements correspond to a plurality of buffers, and information corresponding to the DL RS received from each antenna element is stored in each buffer corresponding to each antenna element. A terminal, wherein the terminal beam is identified based on information stored in the plurality of buffers.

12. In paragraph 7, The above configuration information includes information about multiple DL RS resources, A terminal in which the above DL RS is received from an activated DL RS resource among the plurality of DL RS resources, and information about the activated DL RS resource is received through a MAC CE (medium access control control element).

13. In a method performed by a base station in a communication system, A step of transmitting configuration information for DL ​​RS (downlink reference signal) related to BM (beam management) through upper layer signaling; A step of transmitting a physical downlink control channel (PDCCH) including downlink control information (DCI) for scheduling a data channel, the DCI including information related to triggering the DL RS; a step of transmitting the above DL RS; and Comprising a step of performing communication on the above data channel, A method wherein a first terminal beam corresponding to the PDCCH is different from a second terminal beam corresponding to the data communication, and the second terminal beam is based on the DL RS.

14. In paragraph 13, The above DL RS is transmitted in at least some of the symbols between the last symbol of the PDCCH and before the first symbol of the data channel, A method wherein the above symbols are related to a time required for a terminal to identify the second terminal beam based on the DL RS and apply it to communication of the data channel, and the time required for the terminal is reported as terminal capability.

15. In the base station of the communication system, Transmitter and receiver; and A processor coupled to the transceiver, the processor comprising: Transmitting configuration information for DL ​​RS (downlink reference signal) related to BM (beam management) through upper layer signaling; Transmitting a physical downlink control channel (PDCCH) that contains downlink control information (DCI) for scheduling a data channel, the DCI including information related to triggering the DL RS; Transmitting the above DL RS; and is set to perform communication on the above data channel, A base station, wherein a first terminal beam corresponding to the PDCCH is different from a second terminal beam corresponding to the data communication, and the second terminal beam is based on the DL RS.

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