Method and apparatus for measuring strength of reference signal in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. A method performed by a user equipment (UE) in a wireless communication system, according to various embodiments of the present disclosure, may comprise the steps of: acquiring period information about at least one new beam that differs from the current beam; determining an evaluation period for the at least one new beam on the basis of the period information; measuring a first signal received through the current beam and a second signal received through the at least one new beam within the evaluation period; and transmitting, to a base station, a message for reporting the measurement result.

Description

Method and device for measuring the strength of a reference signal in a wireless communication system

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a method and device for a terminal to measure the strength of a reference signal in a wireless communication system.

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

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

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

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

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

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

[0008] The present disclosure provides a method and device for a terminal to measure the strength of a reference signal in a wireless communication system, and more particularly, a method and device for measuring a specific beam of a serving cell.

[0009] According to various embodiments of the present disclosure, a method performed by a user equipment (UE) in a wireless communication system may include: obtaining period information for at least one new beam different from a current beam; determining an evaluation period for the at least one new beam based on the period information; measuring a first signal received through the current beam and a second signal received through the at least one new beam within the evaluation period; and transmitting a message for reporting a result of the measurement to a base station.

[0010] According to various embodiments of the present disclosure, a user equipment (UE) may include: at least one transceiver; at least one processor communicatively coupled to the at least one transceiver; and at least one memory communicatively coupled to the at least one processor and storing instructions, wherein the instructions are individually or in any combination executed by the at least one processor to cause the UE to: obtain periodic information for at least one new beam different from a current beam; determine an evaluation period for the at least one new beam based on the periodic information; measure a first signal received through the current beam and a second signal received through the at least one new beam within the evaluation period; and transmit a message for reporting a result of the measurement to a base station.

[0011] According to various embodiments of the present disclosure, one or more non-transitory computer-readable storage media storing computer-executable instructions, which when individually or collectively executed by at least one processor of a user equipment (UE), cause the UE to: obtain periodic information for at least one new beam different from a current beam, determine an evaluation period for the at least one new beam based on the periodic information, measure a first signal received through the current beam and a second signal received through the at least one new beam within the evaluation period, and transmit a message for reporting a result of the measurement to a base station.

[0012] As the present disclosure provides a method and device for a terminal to measure the strength of a reference signal, reference signals of different periods can be correctly evaluated.

[0013] FIG. 1 illustrates the basic structure of a time-frequency resource domain in a wireless communication system according to one embodiment of the present disclosure.

[0014] FIG. 2 illustrates a time domain mapping structure and beam sweeping operation of a synchronization signal according to one embodiment of the present disclosure.

[0015] FIG. 3 illustrates a signal flow for random access (RA) according to one embodiment of the present disclosure.

[0016] FIG. 4 illustrates a signal flow for a terminal to report terminal capability information to a base station according to one embodiment of the present disclosure.

[0017] FIG. 5 illustrates an example of a terminal-initiated beam reporting procedure according to one embodiment of the present disclosure.

[0018] FIG. 6A illustrates an example of measuring and evaluating a reference signal of a terminal in method 1 according to one embodiment of the present disclosure.

[0019] FIG. 6b illustrates an example of measuring and evaluating a reference signal of a terminal in method 2 according to one embodiment of the present disclosure.

[0020] FIG. 7 illustrates an example of measuring and evaluating a reference signal of a terminal in method 3 according to one embodiment of the present disclosure.

[0021] FIG. 8 illustrates an example of measuring and evaluating a reference signal of a terminal in method 4 according to one embodiment of the present disclosure.

[0022] FIG. 9 illustrates an example of measuring and evaluating a reference signal of a terminal in method 5 according to one embodiment of the present disclosure.

[0023] FIG. 10 is a block diagram illustrating the functional structure of a terminal in a wireless communication system according to an embodiment of the present disclosure.

[0024] FIG. 11 is a block diagram illustrating the structure of a base station in a wireless communication system according to an embodiment of the present disclosure.

[0025] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the attached drawings. It should be noted that, where possible, identical components are represented by identical reference numerals throughout the attached drawings. Furthermore, detailed descriptions of well-known functions and configurations that may obscure the gist of the present disclosure will be omitted.

[0026] In describing the embodiments of this disclosure, descriptions of technical details that are well known in the technical field to which this disclosure pertains and are not directly related to this disclosure will be omitted. This is to more clearly convey the gist of this disclosure without obscuring it by omitting unnecessary explanations.

[0027] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0028] 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 with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to ensure that the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals designate like elements throughout the disclosure.

[0029] 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).

[0030] 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.

[0031] 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.

[0032] 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.

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

[0034] In the following description, the terms "physical channel" and "signal" may be used interchangeably with data or control signals. For example, while PDSCH (physical downlink shared channel) refers to a physical channel through which data is transmitted, PDSCH may also be used to refer to data. That is, in the present disclosure, the expression "transmitting a physical channel" may be interpreted equivalently to the expression "transmitting data or a signal through a physical channel."

[0035] Hereinafter, in the present disclosure, upper signaling refers to a signal transmission method in which a base station transmits a signal to a terminal using a downlink data channel of the physical layer, or a terminal transmits a signal to a base station using an uplink data channel of the physical layer. Upper signaling can be understood as radio resource control (RRC) signaling or a media access control (MAC) control element (CE).

[0036] Furthermore, while this disclosure describes various embodiments using terminology used in certain communication standards (e.g., 3rd Generation Partnership Project (3GPP)), these are merely illustrative examples. The various embodiments of this disclosure can be easily modified and applied to other communication systems. Furthermore, the term "terminal" can refer to not only cell phones, smartphones, IoT devices, and sensors, but also other wireless communication devices.

[0037] 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, an eNB, 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. Of course, the present invention is not limited to the above examples. In addition, although various embodiments of the present invention are described below using a system based on LTE, LTE-A, or NR as an example, various embodiments of the present invention may be applied to other communication systems having a similar technical background or channel type. In addition, various embodiments of the present invention may be applied to other communication systems through some modifications without significantly departing from the scope thereof at the discretion of a person having skilled technical knowledge.

[0038] To handle the explosive growth in mobile data traffic, the initial standards for the 5G (5th generation) system, or NR (new radio access technology), the next-generation communication system following LTE (long term evolution or E-UTRA (evolved universal terrestrial radio access)) and LTE-A (LTE-advanced or E-UTRA Evolution), have been completed. While existing mobile communication systems have focused on conventional voice / data communications, the 5G system aims to satisfy various services and requirements, such as enhanced Mobile BroadBand (eMBB) services to improve existing voice / data communications, ultra-reliable and low latency communication (URLLC) services, and massive machine type communication (MTC) services that support large-scale machine-type communication.

[0039] While the transmission bandwidth of existing LTE and LTE-A systems per single carrier is limited to a maximum of 20 MHz, the 5G system aims to utilize a much wider ultra-wide bandwidth to provide ultra-high-speed data services of up to several Gbps. Accordingly, the 5G system is considering ultra-high frequency bands ranging from several GHz up to 100 GHz as candidate frequencies, where securing ultra-wide bandwidth frequencies is relatively easy. Additionally, wide bandwidth frequencies for the 5G system can be secured through frequency reallocation or allocation within frequency bands ranging from several hundred MHz to several GHz used in existing mobile communication systems.

[0040] Ultra-high frequency radio waves have wavelengths on the order of millimeters, sometimes called millimeter waves (mmWave). However, in ultra-high frequency bands, path loss increases proportionally to the frequency band, reducing the coverage of mobile communication systems.

[0041] To overcome the drawback of reduced coverage in ultra-high frequency bands, beamforming technology is applied, which uses multiple antennas to focus radio wave energy toward a predetermined target point and thereby increase the transmission range. In other words, a signal using beamforming technology has a relatively narrow beam width, and the radiation energy is concentrated within this narrowed beam width, increasing the transmission range. Beamforming technology can be applied to both the transmitter and receiver. In addition to increasing coverage, beamforming technology also reduces interference in areas outside the beamforming direction. For beamforming technology to function properly, accurate measurement and feedback methods for the transmission and reception beams are required. Beamforming technology can be applied to control channels or data channels that correspond one-to-one between a given terminal and a base station. Furthermore, beamforming can also be applied to common signals transmitted by a base station to multiple terminals within a system, such as synchronization signals, physical broadcast channels (PBCHs), and control and data channels for transmitting system information, to increase coverage. When applying beamforming technology to a common signal, beam sweeping technology, which transmits a signal by changing the beam direction, is additionally applied so that the common signal can reach terminals located at any location within the cell.

[0042] Another requirement for 5G systems is ultra-low latency services, with transmission delays of approximately 1ms between transmitters and receivers. One way to reduce transmission delay is to design a frame structure based on a short transmission time interval (TTI) compared to LTE and LTE-A. A TTI is the basic unit of time for scheduling, and the TTI of existing LTE and LTE-A systems is 1ms, which corresponds to the length of one subframe. For example, to meet the ultra-low latency requirements of 5G systems, possible short TTIs include 0.5ms, 0.25ms, and 0.125ms, which are shorter than those of existing LTE and LTE-A systems.

[0043] Figure 1 illustrates the basic structure of a time-frequency resource domain in a wireless communication system.

[0044] Figure 1 is a diagram showing the basic structure of a time-frequency resource area, which is a radio resource area in which data or control channels of a 5G system are transmitted.

[0045] Referring to Figure 1, the horizontal axis in Figure 1 represents the time domain and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain of a wireless communication system is an OFDM (orthogonal frequency division multiplexing) symbol. The dog symbols (102) come together to form one slot (106), A plurality of slots can be combined to form a subframe (105). The length of the subframe is 1.0 ms, and 10 subframes can be combined to form a 10 ms frame (114). The minimum transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission bandwidth is a total of N BW It can be composed of (104) subcarriers.

[0046] The basic unit of resources in the time-frequency domain is a resource element (RE) (112), which can be represented by an OFDM symbol index and a subcarrier index. A resource block (RB or physical resource block, PRB) is a resource block in the frequency domain. can be defined as a series of consecutive subcarriers (110). In the 5G system = 12, and the data rate can increase in proportion to the number of RBs scheduled to the terminal.

[0047] In wireless communication systems, a base station can map data in RB units and perform scheduling on RBs, which typically constitute a slot for a given terminal. That is, in a 5G system, the basic time unit for scheduling may be a slot, and the basic frequency unit for scheduling may be an RB.

[0048] Number of OFDM symbols It is determined by the length of the cyclic prefix (CP) added to each symbol to prevent interference between symbols. For example, if the normal CP is applied, = 14, when Extended CP is applied = can be 12. Extended CP is applied to systems with relatively long transmission distances compared to general CP, and can maintain orthogonality between symbols. In the case of general CP, since the ratio of CP length to symbol length is maintained at a constant value, the overhead due to CP can be maintained constant regardless of the subcarrier spacing. That is, if the subcarrier spacing is small, the symbol length becomes longer, and thus the CP length can also become longer. Conversely, if the subcarrier spacing is large, the symbol length becomes shorter, and thus the CP length can be reduced. The symbol length and CP length can be inversely proportional to the subcarrier spacing.

[0049] In wireless communication systems, various frame structures can be supported by adjusting the subcarrier spacing to satisfy various services and requirements. For example, from the perspective of operating frequency band, a larger subcarrier spacing is advantageous for recovering phase noise in high-frequency bands. From the perspective of transmission time, a larger subcarrier spacing shortens the symbol length in the time domain, which in turn shortens the slot length, making it advantageous for supporting ultra-low-latency services such as URLLC. From the perspective of cell size, a longer CP length allows for larger cells, so a smaller subcarrier spacing allows for relatively larger cells. In mobile communications, a cell is a concept referring to the area covered by a single base station.

[0050] Subcarrier spacing, CP length, etc. are essential information for OFDM transmission and reception. For smooth transmission and reception, the base station and terminal must recognize the subcarrier spacing, CP length, etc. as common values.

[0051] [Table 1] below shows the relationship between the subcarrier spacing configuration (μ), subcarrier spacing (△f), and CP length supported in the 5G system.

[0052]

[0053] [Table 2] below shows the number of symbols per slot for each subcarrier spacing setting (μ) for the general CP. ), number of slots per frame ( ), number of slots per subframe ( ) is indicated.

[0054]

[0055] [Table 3] below shows the number of symbols per slot (μ) for each subcarrier spacing setting for extended CP. ), number of slots per frame ( ), number of slots per subframe ( ) is indicated.

[0056]

[0057] In the early stages of 5G system deployment, coexistence or dual-mode operation with existing LTE and / or LTE-A (hereinafter referred to as LTE / LTE-A) systems was anticipated. This would allow existing LTE / LTE-A systems to provide stable system operation to terminals, while the 5G system would provide enhanced services to terminals. Therefore, the 5G system's frame structure must at least include the LTE / LTE-A frame structure or essential parameter set (e.g., subcarrier spacing = 15 kHz).

[0058] For example, comparing a frame structure with a subcarrier spacing setting μ=0 (hereinafter referred to as frame structure A) and a frame structure with a subcarrier spacing setting μ=1 (hereinafter referred to as frame structure B), compared to frame structure A, frame structure B shows that the subcarrier spacing and RB size are twice as large, and the slot length and symbol length are twice as small. In the case of frame structure B, two slots can constitute one subframe, and 20 subframes can constitute one frame.

[0059] Generalizing the frame structure of a 5G system provides high scalability by ensuring that essential parameters—subcarrier spacing, CP length, and slot length—have integer multiple relationships for each frame structure. A fixed-length subframe of 1 ms can be defined to represent a reference time unit independent of the frame structure.

[0060] The frame structure can be applied to various scenarios. From the perspective of cell size, the longer the CP length, the larger the cell can be supported, so frame structure A can support relatively larger cells than frame structure B. From the perspective of operating frequency band, the larger the subcarrier spacing, the more advantageous it is for recovering phase noise in the high-frequency band, so frame structure B can support relatively higher operating frequencies than frame structure A. From the perspective of service, the shorter the slot length, which is the basic time unit of scheduling, the more advantageous it is for supporting ultra-low-latency services such as URLLC, so frame structure B can be relatively more suitable for URLLC services than frame structure A.

[0061] In the following description of the present disclosure, uplink (UL) may refer to a wireless link through which a terminal transmits data or a control signal to a base station, and downlink (DL) may refer to a wireless link through which a base station transmits data or a control signal to a terminal.

[0062] In the initial access stage where a terminal first accesses the system, the terminal can synchronize downlink time and frequency from a synchronization signal transmitted by a base station through cell search, and obtain a cell identifier (cell ID). The terminal can receive a physical broadcast channel (PBCH) using the obtained cell ID, and obtain a master information block (MIB), which is essential system information, from the PBCH. Additionally, the terminal can obtain cell-common transmission and reception-related control information by receiving system information (system information block, SIB) transmitted by the base station. The cell-common transmission and reception-related control information may include random access (RA)-related control information, paging-related control information, and common control information for various physical channels.

[0063] The synchronization signal serves as a reference for cell search, and the subcarrier spacing can be applied to suit channel conditions such as phase noise for each frequency band. In the case of data channels or control channels, the subcarrier spacing can be adaptively applied depending on the service type to support various services as described above.

[0064] Figure 2 illustrates the time domain mapping structure and beam sweeping operation of a synchronization signal.

[0065] Hereinafter, the following components may be predefined for the purpose of explaining the present disclosure.

[0066] - PSS (primary synchronization signal): A signal that serves as the basis for DL ​​time / frequency synchronization and can provide some cell ID information.

[0067] - SSS (secondary synchronization signal): It serves as a reference for DL ​​time / frequency synchronization and can provide some remaining information, including the cell ID. Additionally, it can serve as a reference signal (RS) for PBCH demodulation.

[0068] - PBCH (physical broadcast channel): It can provide MIB (master information block), which is essential system information required for transmission and reception of data channels and control channels of the terminal. Essential system information can include control information related to the search space indicating radio resource mapping information of the control channel, scheduling control information for a separate data channel that transmits system information, and SFN (system frame number), which is a frame-unit index that serves as a timing reference.

[0069] - SS / PBCH block (synchronization signal / PBCH block or SSB): An SS / PBCH block can be composed of N OFDM symbols and can include a combination of PSS, SSS, PBCH, etc. In a system where beam sweeping technology is applied, an SS / PBCH block can be the minimum unit to which beam sweeping is applied. In a 5G system, N can be 4. The base station can transmit up to L SS / PBCH blocks, and the L SS / PBCH blocks can be mapped within a half frame (0.5 ms). The L SS / PBCH blocks can be periodically repeated in units of a predetermined period P. The period P can be notified to the terminal by signaling from the base station. If there is no separate signaling for the period P, the terminal can apply a pre-agreed default value.

[0070] FIG. 2 illustrates an example in which beam sweeping is applied to SS / PBCH block units over time. In the example of FIG. 2, terminal 1 (205) can receive an SS / PBCH block using a beam radiated in the direction of #d0 (203) by beamforming applied to SS / PBCH block #0 at time t1 (201). Terminal 2 (206) can receive an SS / PBCH block using a beam radiated in the direction of #d4 (204) by beamforming applied to SS / PBCH block #4 at time t2 (202). The terminal can obtain an optimal synchronization signal through a beam radiated from the base station in the direction where the terminal is located. For example, terminal 1 (205) may have difficulty in obtaining time / frequency synchronization and essential system information from an SS / PBCH block through a beam radiated in the direction of #d4 (204) which is far from the location of terminal 1 (205).

[0071] In addition to the initial connection procedure, the terminal may receive SS / PBCH blocks to determine whether the radio link quality of the current cell is maintained at a certain level. Furthermore, during a handover procedure, in which the terminal moves from the current cell to a neighboring cell, the terminal may receive SS / PBCH blocks from the neighboring cell to determine the radio link quality of the neighboring cell and obtain time / frequency synchronization with the neighboring cell.

[0072] After the terminal acquires MIB and system information from the base station through the initial access procedure, the terminal can perform a random access procedure to transition the link with the base station to the connected state (or RRC_CONNECTED state). Upon completion of the random access procedure, the terminal transitions to the connected state (or RRC_CONNECTED state), enabling one-to-one communication between the base station and the terminal. The random access procedure is described in detail below with reference to FIG. 3.

[0073] Figure 3 illustrates the flow of signals for random access (RA).

[0074] Referring to FIG. 3, in step 310, a terminal may transmit a random access preamble to a base station. The random access preamble, which is the first transmission message of the terminal in the random access procedure, may be referred to as message 1. The base station may measure a transmission delay value between the terminal and the base station from the random access preamble and synchronize uplink. At this time, the terminal may arbitrarily select which random access preamble to use within a random access preamble set given in advance by system information. The initial transmission power of the random access preamble may be determined according to the path loss measured by the terminal between the base station and the terminal. In addition, the terminal may determine the transmission beam direction of the random access preamble from the synchronization signal received from the base station and transmit the random access preamble.

[0075] In step 320, the base station may transmit a random access response (RAR) (or message 2) for the random access preamble received in step 310. The base station may transmit an uplink transmission timing adjustment command to the terminal based on a transmission delay value measured from the random access preamble. The base station may transmit to the terminal uplink resources to be used and a power control command as scheduling information. The scheduling information transmitted by the base station may include control information for the uplink transmission beam of the terminal.

[0076] If the terminal does not receive the random access response (RAR) (or message 2), which is scheduling information for message 3, from the base station within a predetermined time in step 320, step 310 may be performed again. If step 310 is performed again, the terminal may increase the probability of the base station receiving the random access preamble by transmitting the random access preamble with a transmission power increased by a predetermined step (e.g., power ramping).

[0077] In step 330, the terminal can transmit uplink data including its terminal ID (i.e., message 3) to the base station using the uplink resources allocated in step 320. The terminal can transmit the uplink data including the terminal ID to the base station through an uplink data channel (physical uplink shared channel, PUSCH). The transmission timing of the uplink data channel for transmitting Message 3 may follow the timing control command received from the base station in step 320. The transmission power of the uplink data channel for transmitting Message 3 may be determined by considering the power control command received from the base station in step 320 and the power ramping value of the random access preamble. The uplink data channel for transmitting Message 3 may mean the first uplink data signal that the terminal transmits to the base station after transmitting the random access preamble.

[0078] In step 340, if the base station determines that the terminal has performed random access without collision with other terminals, it can transmit data (i.e., message 4) including the ID of the terminal that transmitted uplink data in step 330 to the terminal. If the terminal receives the signal transmitted by the base station in step 340 from the base station, it can determine that the random access has been successful. The terminal can transmit HARQ-ACK (hybrid automatic repeat request acknowledgment) information indicating whether message 4 was successfully received to the base station through the uplink control channel (physical uplink control channel, PUCCH).

[0079] If the data transmitted by the terminal in step 330 collides with data from another terminal, causing the base station to fail to receive a data signal from the terminal, the base station may not transmit any more data to the terminal. If the terminal fails to receive the data transmitted from the base station in step 340 within a certain period of time, it may determine that the random access procedure has failed and may proceed again from step 310.

[0080] When a terminal successfully completes a random access procedure, the terminal transitions to a connected state (or RRC_CONNECTED state), and one-to-one communication can be enabled between the base station and the terminal. The base station can receive terminal capability (UE capability) information from the terminal in the connected state (or RRC_CONNECTED state) and adjust scheduling by referring to the terminal capability (UE capability) information of the corresponding terminal. Through the terminal capability (UE capability) information, the terminal can inform the base station whether it supports a certain function, the maximum allowable value of the function supported by the terminal, etc. Therefore, the terminal capability (UE capability) information reported by each terminal to the base station can have different values ​​for each terminal.

[0081] For example, a terminal may report terminal capability information including at least one of the following control information to a base station.

[0082] - Control information related to frequency bands supported by the terminal

[0083] - Control information related to channel bandwidth supported by the terminal

[0084] - Control information related to the maximum modulation method supported by the terminal

[0085] - Control information related to the maximum number of beams supported by the terminal

[0086] - Control information related to the maximum number of layers supported by the terminal

[0087] - Control information related to CSI reporting supported by the terminal

[0088] - Control information on whether the terminal supports frequency hopping

[0089] - Bandwidth-related control information when supporting carrier aggregation (CA)

[0090] - Control information on whether cross carrier scheduling is supported when carrier aggregation is supported.

[0091] Figure 4 illustrates the flow of signals for a terminal to report terminal capability information to a base station.

[0092] Referring to FIG. 4, at step 410, the base station (402) may transmit a UE capability information request message to the terminal (401). Based on the UE capability information request from the base station (402), the terminal (401) may transmit UE capability information to the base station at step 420. According to one embodiment, the terminal (401) may transmit UE capability information to the base station (402) regardless of the UE capability information request from the base station (402).

[0093] Based on the transmission and reception process of terminal capability information, a terminal connected to a base station can communicate one-to-one with the base station as a terminal in the RRC_CONNECTED state. Conversely, a terminal that is not connected can be in the RRC_IDLE state, and a terminal in the RRC_IDLE state can perform the following processes.

[0094] - Performs terminal-specific DRX (discontinuous reception) cycles set by the upper layer.

[0095] - Receive paging messages from the core network

[0096] - Obtain system information

[0097] - Measurement actions related to serving cells (or camping cells) and cell selection / reselection

[0098] - Measurement operations related to surrounding cells and cell reselection

[0099] In more detail with respect to the measurement operation and cell selection / reselection related to the serving cell (or the cell on which the UE is camping) (referred to as MR (main radio) RRM (radio resource management) measurement / evaluation in this disclosure), the UE can measure the SS-RSRP (synchronization signal - reference signal received power) and SS-RSRQ (synchronization signal - reference signal received quality) levels for the serving cell (or the cell on which the UE is camping) at least every M1*N1 DRX cycle, and evaluate the cell selection decision criterion S based on the measured values. Here, when the SMTC (SSB-based measurement timing configuration) period is greater than 20ms and the DRX cycle is less than or equal to 0.64s, M1=2, and in other cases, M1=1.

[0100] N1 can be determined by the following table.

[0101]

[0102] The cell selection criterion S corresponds to SS-RSRP rxlev > 0 and S corresponding to SS-RSRQ qual > 0 can be satisfied.

[0103] S rxlev = Q rxlevmeas - (Q rxlevmin + Q rxlevminoffset )- Pcompensation - Q offsettemp

[0104] S qual = Q qualmeas - (Q qualmin + Q qualminoffset ) - Q offsettemp

[0105] Here, Q rxlevmeas is the measured SS-RSRP, and Q qualmeas is the measured SS-RSRQ, and Q rxlevmin is the minimum required reception signal level in the serving cell and can be received by the terminal as system information, and Q qualmin is the quality level of the received signal required at the minimum limit in the serving cell and can be received by the terminal as system information. The remaining parameters are presented in 3GPP TS 38.304. The terminal can determine the SS-RSRP of the serving cell by filtering from at least two measurement values ​​that are spaced apart by at least half a DRX cycle in determining the measured SS-RSRP. In addition, the terminal can determine the SS-RSRQ of the serving cell by filtering from at least two measurement values ​​that are spaced apart by at least half a DRX cycle in determining the measured SS-RSRQ.

[0106] More specifically, regarding the measurement behavior and cell reselection related to surrounding cells, the terminal is N serv If the UE determines that the serving cell does not satisfy the cell selection criterion S during consecutive DRX cycles, the UE may initiate measurements of all surrounding cells other than the serving cell. If the UE fails to find a new suitable cell for 10 s, the UE may initiate a cell selection procedure for the selected public land mobile network (PLMN).

[0107] Terminal is N servEven if the serving cell satisfies the cell selection criterion S during consecutive DRX cycles, if the network has set inter-frequency layers of higher priority, the UE must search for cells of that frequency layer at least every Thigher_prioirty_search. If the UE serv If the serving cell does not satisfy the cell selection criterion S during consecutive DRX cycles and the network sets inter-frequency layers of lower, higher priority, the terminal may search for lower, same, and higher frequency layer cells as in the measurement cycle described below.

[0108] The terminal starts measuring the surrounding cells every T measure Measure the SS-RSRP and SS-RSRQ levels every T and the surrounding cells evaluate It can be evaluated whether the cell reselection criteria are satisfied within the newly detected cell. The newly detected cell is selected every T detect It can be evaluated whether the cell reselection criteria are satisfied. T reselection During the cell reselection, if a neighboring cell is better than the serving cell based on the cell reselection judgment criteria, and at the same time, if more than 1 second has passed since the terminal camped on the current serving cell, the terminal can reselect the neighboring cell as the new serving cell. Here, the T measure , T evaluate , T reselection Parameters such as may be determined in the specification according to the DRX cycle or may be set by a higher level signal. The terminal may determine the measured SS-RSRP by at least T measure The SS-RSRP of the surrounding cells can be determined by filtering from at least two measurements that are half a distance apart.

[0109] The above cell reselection judgment criteria are calculated by the following parameters R s , R n The cell selection order can be determined based on R. s , R n You can determine the cell ranking in order of highest value across all.

[0110] R s = Q meas,s + Q hyst - Qoffset temp

[0111] R n = Q meas,n - Qoffset - Qoffset temp

[0112] Here, Q meas,s , Q meas,n represents the RSRP measurement values ​​of the serving cell and surrounding cells, respectively, and Q hyst , Qoffset, Qoffset temp The back can be set by a higher signal.

[0113] When a specific condition is satisfied in relation to the measurement of surrounding cells, the measurement of surrounding cells is stopped or the above T measure It is possible to perform surrounding cell measurements by a longer period. In one embodiment, if the terminal is moving slowly or stopped within the cell, or if it is determined that the terminal is not at the cell edge, the terminal may perform T measure You can measure surrounding cells at longer intervals by multiplying the scaling factor, or stop measuring surrounding cells for up to 1 hour.

[0114] In 5G systems, a new terminal state called RRC_INACTIVE has been defined to reduce the energy and time consumed during initial access. In addition to the actions performed by RRC_IDLE terminals, RRC_INACTIVE terminals can perform the following processes:

[0115] - Storage of AS (access stratum) information required for cell access

[0116] - Terminal-specific DRX cycle operation set by the RRC layer

[0117] - Setting up and periodically updating RNA (RAN (radio access network)-based notification area) that can be utilized during handover by the RRC layer

[0118] - Monitoring of RAN-based paging messages transmitted via I-RNTI (inactive-radio network temporary identifier)

[0119] A terminal in RRC_CONNECTED state can change from RRC_CONNECTED to RRC_INACTIVE or RRC_IDLE state by receiving an RRC Release instruction from the base station.

[0120] A terminal in RRC_INACITVE or RRC_IDLE state can change from RRC_INACTIVE or RRC_IDLE to RRC_CONNECTED state by performing random access and completing all random access procedures.

[0121] Based on the transmission and reception process of terminal capability information, a terminal connected to a base station can communicate one-to-one with the base station as a terminal in the RRC_CONNECTED state. A terminal in the RRC_CONNECTED state can perform the following actions:

[0122] - Monitoring of the Physical Downlink Control Channel (PDCCH)

[0123] - Radio link monitoring

[0124] - Beam failure detection and beam failure recovery

[0125] First, the monitoring of the downlink control channel of a terminal in RRC_CONNECTED state will be described in detail. If DRX (Discontinuous Reception) is not configured from the base station, the MAC (medium access control) entity of the terminal can continuously monitor the PDCCH. If DRX is configured to the MAC entity of the terminal by a higher-order signal from the base station, the MAC entity of the terminal can discontinuously monitor the PDCCH using the DRX operation for all activated serving cells. The terminal can receive DRX operation-related parameters (e.g., at least one of DRX cycle, drx-onDurationTimer, drx-InactivityTimer, or drx-SlotOffset) from the base station by a higher-order signal, and discontinuously monitor the PDCCH based on the parameters. In the present disclosure, the terminal in the RRC_CONNECTED state may be said to perform a C-DRX (CONNECTED-DRX) operation by monitoring the PDCCH with DRX, or may be expressed as performing C-DRX.

[0126] Next, radio link monitoring of a terminal in RRC_CONNECTED state will be described in detail. The terminal performs radio link monitoring for a serving cell (or a primary serving cell (primary cell), i.e., Pcell, when carrier aggregation is configured) using a CSI-RS (channel state information-reference signal) or an SS / PBCH signal. Performing radio link monitoring can be explained as measuring the quality of the radio link using the above signals to determine whether the radio link is in-sync or out-of-sync. Which signal, the CSI-RS or the SS / PBCH signal, is used for radio link monitoring can be set by receiving an upper signal from a base station.

[0127] When measuring the quality of the above radio link, the evaluation period for measuring and evaluating whether it is in-sync or out-of-sync is described. The in-sync evaluation period and the out-of-sync evaluation period can be determined differently depending on whether DRX is set for PDCCH monitoring from the base station, and if DRX is set, the DRX cycle value. Next, the indication period for sending the evaluated in-sync or out-of-sync from the physical layer of the terminal to the upper layer of the terminal as a result of the measurement and evaluation is described. If DRX is not set, the indication period is determined as the maximum value between the shortest cycle of the resource for radio link monitoring and 10ms. Conversely, if DRX is set, the indication period is determined as the maximum value between the shortest cycle of the resource for radio link monitoring and the DRX cycle.

[0128] The above in-sync will be described. If the radio link quality is better than the threshold Q_in received from the base station configuration for any resources in the resource set for radio link monitoring, the physical layer of the terminal transmits in-sync to the upper layer of the terminal in the frame in which the radio link quality is evaluated. In order to determine the in-sync of the radio link quality, the terminal determines whether the block error rate (BLER) when performing PDCCH decoding from hypothetical downlink control channel (hypothetical PDCCH) parameters is less than a predefined value. The predefined value can be, for example, 2%. The above downlink control channel parameters can be determined differently depending on which signal is used to perform radio link monitoring.

[0129] The above out-of-sync is explained. If the radio link quality is worse than the threshold Q_out received from the base station configuration for any resources in the resource set for radio link monitoring, the physical layer of the terminal transmits an out-of-sync signal to the upper layer of the terminal in the frame in which the radio link quality is evaluated. In order to determine the out-of-sync of the radio link quality, the terminal determines whether the block error rate when performing PDCCH decoding from virtual downlink control channel parameters is greater than a predefined value. The predefined value can be, for example, 10%. The above downlink control channel parameters can be determined differently depending on which signal is used to perform radio link monitoring.

[0130] The upper layer of the terminal (or the terminal) starts the T310 timer after receiving N310 consecutive out-of-syncs. If the terminal receives N311 consecutive in-syncs, the T310 timer is stopped. Otherwise, the terminal declares RLF (Radio Link Failure) and starts the T311 timer. The terminal performs cell selection to find a suitable cell. If no suitable cell is found and the T311 timer expires, the terminal transitions to the RRC_IDLE state. If a suitable cell is found, the T311 timer is stopped, and the terminal transmits an RRC Reestablishment Request message to the base station of the cell and starts the T301 timer. If the RRC Reestablishment operation is not successfully completed and the T301 timer expires, the terminal transitions to the RRC_IDLE state. If the RRC Reestablishment operation is successfully completed within the T301 timer, the terminal transitions to the normal RRC_CONNECTED state.

[0131] Parameters and timers for performing procedures related to radio link monitoring and radio link failure, such as the above N310, T310 timer, N311, T311 timer, and T301 timer, can be set to the terminal by an upper signal from the base station.

[0132] Next, the Beam Failure Detection (BFD) and Beam Failure Recovery (BFR) of a terminal in the RRC_CONNECTED state are described in detail. The terminal performs beam failure detection for a serving cell using a CSI-RS or SS / PBCH signal. Performing beam failure detection can be explained as measuring the quality of a beam using the signals and determining whether the reception status of the beam is reliable (for example, whether the virtual downlink control channel block error rate for the measured beam quality is less than a predefined value).

[0133] If the reception status of the beam is unreliable, that is, if the virtual downlink control channel block error rate for the measured beam quality is equal to or greater than the predefined value, this is defined as a beam failure instance. Which signal among the CSI-RS or SS / PBCH signal is used to perform beam failure detection can be configured by receiving an upper signal from the base station. In order to determine the virtual downlink control channel block error rate, the terminal determines whether the block error rate when performing PDCCH decoding is greater than a predefined value based on virtual downlink control channel parameters (e.g., a specific DCI format, the number of OFDM symbols of the PDCCH, the PDCCH Aggregation level, the PDCCH bandwidth, the subcarrier spacing, the REG (resource element group) bundle size, the CP (cyclic prefix) length, etc.). The predefined value can be, for example, 10%. The downlink control channel parameters can be determined differently depending on which signal is used to perform beam failure detection.

[0134] When the above beam failure instance increases by 1, the timer (beamFailureDetectionTimer) related to the beam failure instance is restarted, and when the terminal (or the MAC layer of the terminal) does not determine an additional beam failure instance until the timer expires, the accumulated beam failure instance (BFI_COUNTER) is reset.

[0135] When the number of accumulated beam failure instances is equal to or greater than the maximum number of beam failure instances (beamFailureInstanceMaxCount) set by the base station as an upper signal, the terminal (or the MAC layer of the terminal) can trigger beam failure recovery. When the beam failure recovery is triggered, the terminal (or the MAC layer of the terminal) can perform beam failure recovery by performing random access to the base station using the resources or random access preamble set for the best candidate beam. The terminal can perform contention-free random access (CFRA) using the downlink control channel resources (control resource set, CORESET) set by the base station and the random access preamble for beam failure recovery. If the above-mentioned collision-free random access fails, or there is no best candidate beam allocated for the collision-free random access, or no collision-free random access resource or random access preamble is set, the terminal may perform a collision-prone random access (contention-based random access) (CBRA) to recover from beam failure.

[0136] Below, a scheduling method for a base station to transmit downlink data to a terminal or instruct the terminal to transmit uplink data is described.

[0137] Downlink control information (DCI) may be control information transmitted from a base station to a terminal via the downlink. Downlink control information may include downlink data scheduling information or uplink data scheduling information for a given terminal. Typically, the base station independently performs channel coding on DCI for each terminal and then transmits it to each terminal via a physical downlink control channel (PDCCH).

[0138] The base station can operate by applying a DCI format determined for the purpose of scheduling, such as whether it is scheduling information for downlink data (downlink assignment), scheduling information for uplink data (uplink grant), or DCI for power control.

[0139] A base station can transmit downlink data to a terminal via the physical downlink shared channel (PDSCH), a physical channel for downlink data transmission. The base station can inform the terminal of scheduling information, such as the specific mapping location in the time and frequency domains of the PDSCH, modulation scheme, HARQ-related control information, and power control information, through DCI related to downlink data scheduling information among the DCIs transmitted via the PDCCH.

[0140] A terminal can transmit uplink data to a base station via the physical uplink shared channel (PUSCH), a physical channel for uplink data transmission. The base station can inform the terminal of scheduling information, such as the specific mapping location in the time and frequency domains of the PUSCH, modulation method, HARQ-related control information, and power control information, through DCI related to uplink data scheduling information among the DCI transmitted via the PDCCH.

[0141] The time-frequency resources to which the PDCCH is mapped may be referred to as a control resource set (CORESET). A CORESET may be configured for all or part of the frequency resources of the bandwidth supported by the terminal in the frequency domain. In the time domain, it may be configured with one or more OFDM symbols, which may be defined as the CORESET length (control resource set duration). The base station may configure one or more CORESETs to the terminal through higher layer signaling (e.g., system information, master information block (MIB), radio resource control (RRC) signaling). When the base station configures a CORESET to the terminal, this may mean that the base station provides the terminal with information such as a CORESET identifier, the frequency location of the CORESET, and the symbol length of the CORESET. The information that the base station provides to the terminal to configure the CORESET may include at least some of the information included in [Table 5] below.

[0142]

[0143]

[0144] CORESET is in the frequency domain It can be composed of RBs and in the time domain ∈{1,2,3} symbols. The NR PDCCH may be composed of one or more control channel elements (CCEs). One CCE may be composed of six resource element groups (REGs), and a REG may be defined as one RB during one OFDM symbol. Within one CORESET, REGs may be indexed in time-first order, starting with REG index 0 from the first OFDM symbol of the CORESET, the lowest RB.

[0145] Interleaved and non-interleaved transmission methods for PDCCH can be supported. The base station can configure whether to use interleaved or non-interleaved transmission for each CORESET to the terminal through upper layer signaling. Interleaving can be performed on a per REG bundle basis. A REG bundle can be defined as a set of one or more REGs. The terminal can determine the CCE-to-REG mapping method for the corresponding CORESET based on whether to use interleaved or non-interleaved transmission as configured by the base station, as shown in [Table 6] below.

[0146]

[0147] The base station can provide the terminal with configuration information, such as information about the symbol to which the PDCCH is mapped within the slot and the transmission period, through signaling.

[0148] The search space of the PDCCH is described as follows. The number of CCEs required to transmit the PDCCH can be 1, 2, 4, 8, or 16 depending on the aggregation level (AL), and different numbers of CCEs can be used for link adaptation of the downlink control channel. For example, when AL=L, a single downlink control channel can be transmitted through L CCEs. The UE performs blind decoding, which detects a signal without knowing information about the downlink control channel. For this purpose, a search space representing a set of CCEs can be defined. The search space is a set of downlink control channel candidates consisting of CCEs that the UE should attempt to decode at a given aggregation level. Since there are various aggregation levels that create a single group with 1, 2, 4, 8, or 16 CCEs, the UE can have multiple search spaces. A search space set can be defined as the set of search spaces at all established aggregation levels.

[0149] Search spaces can be classified into a common search space (CSS) and a UE-specific search space (USS). A certain group of UEs, or all UEs, can scan the common search space of the PDCCH to receive cell-common control information, such as dynamic scheduling for system information blocks (SIBs) or paging messages. For example, a UE can receive scheduling allocation information for a PDSCH for system information reception by scanning the common search space of the PDCCH. In the case of the common search space, since a certain group of UEs, or all UEs, must receive the PDCCH, it can be defined as a set of pre-arranged CCEs. UE-specific scheduling allocation information for a PDSCH or PUSCH can be received by scanning the UE-specific search space of the PDCCH. The UE-specific search space can be defined UE-specifically as a function of the UE ID and various system parameters.

[0150] The base station can configure the search space configuration information of the PDCCH to the terminal through higher layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station can configure the number of PDCCH candidates at each aggregation level L, the monitoring period for the search space, the monitoring occasion for each symbol within the slot for the search space, the search space type (common search space or terminal-specific search space), the combination of DCI format and RNTI to be monitored in the corresponding search space, the CORESET index to be monitored for the search space, etc. to the terminal. For example, the parameters for the search space for the PDCCH may include information such as the information in [Table 7] below.

[0151]

[0152]

[0153] Based on the configuration information transmitted to the terminal, the base station may configure one or more search space sets for the terminal. According to one embodiment, the base station may configure search space set 1 and search space set 2 for the terminal. In search space set 1, the terminal may be configured to monitor DCI format A scrambled with X-RNTI in a common search space, and in search space set 2, the terminal may be configured to monitor DCI format B scrambled with Y-RNTI in a terminal-specific search space.

[0154] According to the configuration information transmitted by the base station, one or more search space sets may exist in the common search space or the terminal-specific search space. For example, search space set #1 and search space set #2 may be configured as the common search space, and search space set #3 and search space set #4 may be configured as the terminal-specific search space.

[0155] In a common search space, a terminal may monitor the following combinations of DCI formats and RNTIs. Various embodiments of the present disclosure, of course, are not limited to the examples below.

[0156] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI

[0157] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0158] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0159] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0160] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0161] In a terminal-specific search space, a terminal may monitor the following combinations of DCI formats and RNTIs. Various embodiments of the present disclosure, of course, are not limited to the examples below.

[0162] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0163] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0164] RNTIs may follow the following definitions and uses. According to various embodiments of the present disclosure, of course, they are not limited to the examples below.

[0165] - C-RNTI (cell RNTI): For terminal-specific PDSCH or PUSCH scheduling purposes.

[0166] - TC-RNTI (temporary Cell RNTI): For terminal-specific PDSCH scheduling purposes

[0167] - CS-RNTI (configured scheduling RNTI): Used for terminal-specific PDSCH scheduling that is set semi-statically.

[0168] - RA-RNTI (random access RNTI): Used for PDSCH scheduling in the random access phase.

[0169] - P-RNTI (paging RNTI): Used for scheduling PDSCH where paging is transmitted.

[0170] - SI-RNTI (system information RNTI): Used for scheduling PDSCH where system information is transmitted.

[0171] - INT-RNTI (interruption RNTI): Used to indicate whether puncturing is performed on the PDSCH.

[0172] - TPC-PUSCH-RNTI (transmit power control for PUSCH RNTI): Used to indicate power control commands for PUSCH.

[0173] - TPC-PUCCH-RNTI (transmit power control for PUCCH RNTI): Used to indicate power control commands for PUCCH.

[0174] - TPC-SRS-RNTI (transmit power control for SRS RNTI): Used to indicate power control commands for SRS.

[0175] The DCI formats described above can follow the definitions shown in [Table 8] below.

[0176]

[0177] CORESET p, the search space of aggregation level L in the search space set s can be expressed as the following mathematical formula.

[0178]

[0179] - L: Integration level

[0180] - nCI: carrier index

[0181] - NCCE,p: Total number of CCEs within the control resource set p

[0182] - nμs,f: slot index

[0183] - M(L)p,s,max: Number of PDCCH candidates for aggregation level L

[0184] - msnCI = 0, ..., M(L)p,s,max -1: PDCCH candidate index of aggregation level L

[0185] - i = 0, ..., L-1

[0186] -

[0187] - nRNTI: Terminal identifier

[0188] The value can be 0 for a common search space.

[0189] In the case of a terminal-specific search space, the value may correspond to a value that changes depending on the terminal's ID (C-RNTI or ID set to the terminal by the base station) and the time index.

[0190] Below, we describe CSI-RS. NR has a CSI framework for directing base stations to measure and report channel state information (CSI) from terminals. The NR CSI framework can consist of at least two elements: resource settings and report settings. Report settings can reference at least one ID of resource settings to establish a connection relationship with each other.

[0191] According to one embodiment of the present disclosure, resource settings may include information related to a reference signal (RS) for measuring channel state information by a terminal. The base station may configure at least one resource setting for the terminal. For example, the base station and the terminal may exchange signaling information, such as [Table 8a], to convey information regarding resource settings.

[0192]

[0193] In [Table 8a], the signaling information CSI-ResourceConfig includes information about each resource setting. According to the signaling information, each resource setting may include a resource setting index (csi-ResourceConfigId), a BWP index (bwp-ID), a time-domain transmission configuration of the resource (resourceType), or a resource set list (csi-RS-ResourceSetList) including at least one resource set. The time-domain transmission configuration of the resource may be set to aperiodic transmission, semi-persistent transmission, or periodic transmission. The resource set list may be a set including a resource set for channel measurement or a set including a resource set for interference measurement. If the resource set list is a set including resource sets for channel measurement, each resource set may include at least one resource, which may be an index of a CSI reference signal (CSI-RS) resource or a synchronization / broadcast channel block (SS / PBCH block, SSB). If the resource set list is a set including resource sets for interference measurement, each resource set may include at least one interference measurement resource (CSI interference measurement, CSI-IM).

[0194] For example, if the resource set includes CSI-RS, the base station and the terminal can exchange signaling information as in [Table 9] to convey information about the resource set.

[0195]

[0196] In [Table 9], the signaling information NZP-CSI-RS-ResourceSet contains information about each resource set. According to the signaling information, each resource set contains at least information about a resource set index (nzp-CSI-ResourceSetId) or a set of indexes of CSI-RSs included (nzp-CSI-RS-Resources), and may include part of information about a spatial domain transmission filter of the included CSI-RS resource (repetition) or whether the included CSI-RS resource is used for tracking (trs-Info).

[0197] CSI-RS may be the most representative reference signal included in a resource set. The base station and terminal can exchange signaling information, as shown in [Table 10], to convey information about CSI-RS resources.

[0198]

[0199] In [Table 10], the signaling information NZP-CSI-RS-Resource contains information about each CSI-RS. The information contained in the signaling information NZP-CSI-RS-Resource may have the following meanings.

[0200] - nzp-CSI-RS-ResourceId: CSI-RS resource index

[0201] - resourceMapping: Resource mapping information for CSI-RS resources

[0202] - powerControlOffset: Ratio between PDSCH EPRE (Energy Per RE) and CSI-RS EPRE

[0203] - powerControlOffsetSS: Ratio between SS / PBCH block EPRE and CSI-RS EPRE

[0204] - scramblingID: scrambling index of the CSI-RS sequence

[0205] - periodicityAndOffset: Transmission period and slot offset of the CSI-RS resource

[0206] - qcl-InfoPeriodicCSI-RS: TCI-state information if the CSI-RS is a periodic CSI-RS.

[0207] The resourceMapping included in the above signaling information NZP-CSI-RS-Resource indicates resource mapping information of the CSI-RS resource, and may include frequency resource resource element (RE) mapping, number of ports, symbol mapping, CDM type, frequency resource density, and frequency band mapping information. The number of ports, frequency resource density, CDM type, and time-frequency axis RE mapping that can be set through this may have a value set in one of the rows of [Table 11] below.

[0208]

[0209] [Table 11] shows the frequency resource density (density), CDM type, CSI-RS component RE pattern (pattern) frequency axis and time axis start position that can be set according to the number of CSI-RS ports (X) ), represents the number of frequency-axis REs (k') and the number of time-axis REs (l') of the CSI-RS component RE pattern. The aforementioned CSI-RS component RE pattern may be a basic unit configuring a CSI-RS resource. Through Y=1+max(k') REs on the frequency axis and Z=1+max(l') REs on the time axis, the CSI-RS component RE pattern may be composed of YZ REs. When the number of CSI-RS ports is 1 port, the CSI-RS RE position may be designated without limitation of subcarriers in a PRB (Physical Resource Block), and the CSI-RS RE position may be designated by a 12-bit bitmap. When the number of CSI-RS ports is {2, 4, 8, 12, 16, 24, 32} ports and Y=2, CSI-RS RE positions can be specified for every two subcarriers in the PRB, and the CSI-RS RE positions can be specified by a 6-bit bitmap. When the number of CSI-RS ports is 4 ports and Y=4, CSI-RS RE positions can be specified for every four subcarriers in the PRB, and the CSI-RS RE positions can be specified by a 3-bit bitmap. Similarly, time axis RE positions can be specified by a bitmap of a total of 14 bits.

[0210] In the conventional beam management procedure of the UE, the network can configure or activate periodic or semi-persistent beam reporting (e.g., N best beams and their corresponding L1-RSRP), and the network can trigger aperiodic beam reporting frequently to the UE to timely acquire the best / preferred beam for data transmission / control information transmission. However, frequently triggered beam reporting of the UE can result in large uplink reporting and control signaling overhead. If less frequent beam reporting is configured to the UE to reduce the uplink reporting overhead and control signaling overhead, the network may not always acquire the 'best / preferred' beam because the beam reporting by the UE may not reflect the current status, which may lead to performance degradation. Given that the UE is better able to detect better and more timely beam quality changes than the network, a UE-initiated beam reporting procedure (where the UE initiates the beam reporting procedure) can lead to more timely beam reporting while also reducing the reporting overhead. For example, if a terminal determines that its current beam quality has deteriorated, the terminal can trigger a beam report directly without having to configure or trigger frequent reports over the network.

[0211] The terminal can measure the beam quality, and if it detects a deterioration in the beam quality, it can notify the base station that the beam quality has deteriorated. The base station can receive a beam report request from the terminal, allocate resources for beam reporting to the terminal, and receive the beam report from the terminal. The terminal-initiated beam reporting (UEIBM, UE initiated beam management / UE initiated beam reporting) procedure can be divided into Mode A and Mode B. Mode A and Mode B are merely exemplary names for referring to different operation modes, and the technical ideas described in the present disclosure are not limited by the terms.

[0212] FIG. 5 illustrates an example of a terminal-initiated beam reporting procedure according to one embodiment of the present disclosure.

[0213] Referring to mode A (500) of FIG. 5, when UEIBM is set to a terminal, the terminal can initiate measurement and evaluation (501) for a beam.

[0214] In operation 501, the terminal can measure the L1-RSRP (reference signal received power) of the 'current beam' and the 'new beam', and compare the L1-RSRP of the 'current beam' with the L1-RSRP of the 'new beam'. The current beam can mean a reference signal that is quasi co-located (QCL) with an indicated TCI state. Alternatively, the current beam can mean a reference signal that is quasi co-located with an indicated TCI state and a QCL and a SSB that is QCL. A definition of the current beam can be set for the terminal. For example, the terminal can be set to interpret the current beam as meaning a reference signal that is quasi co-located with an indicated TCI state, or the terminal can be set to interpret the current beam as meaning a reference signal that is quasi co-located with an indicated TCI state, or the terminal can be set to interpret the current beam as meaning a reference signal that is quasi co-located with an indicated TCI state, and a SSB that is QCL. The new beam may refer to a reference signal set by upper layer signaling (e.g., RRC or MAC-CE). The reference signal may refer to CSI-RS or SSB, and the current beam and the new beam may assume the same type of reference signal. For example, if the reference signal of the current beam is SSB, the reference signal of the new beam may also be SSB.

[0215] If the L1-RSRP of the new beam is better than the L1-RSRP of the current beam (i.e., the value of the L1-RSRP of the new beam is greater than the value of the L1-RSRP of the current beam), the terminal may transmit a resource request (502) for beam reporting to the base station. According to one embodiment of the present disclosure, if M events (wherein M may be a value that can be set by the base station to the terminal, a predefined value, or a value that can be determined according to the terminal implementation) occur within a time window set as an optional option, the terminal may transmit a resource request for beam reporting to the base station. Here, the resource for beam reporting may be a resource that the terminal can use to perform beam reporting. According to another embodiment of the present disclosure, the terminal may transmit a resource request for beam reporting to the base station if the quality (e.g., L1-RSRP) of the current beam is lower than a set threshold. According to another embodiment of the present disclosure, the terminal sets the lowest L1-RSRP of the activated TCI states as a threshold, and if the L1-RSRP of at least one new beam is better than the threshold, the terminal can transmit a resource request for a beam report to the base station. According to another embodiment of the present disclosure, the terminal sets the highest L1-RSRP of the activated TCI states as a threshold, and if the L1-RSRP of at least one new beam is better than the threshold, the terminal can transmit a resource request for a beam report to the base station. The resource request (502) can be transmitted to the base station by being included in a periodically transmitted physical uplink control channel (PUCCH). The embodiments in which the resource request for the beam report of the terminal is triggered as described above can be selectively used, and at least one of the embodiments described above can be set to the terminal by the base station.

[0216] Thereafter, the terminal can detect a physical downlink control channel (PDCCH) including downlink control information (DCI) indicating beam reporting resources in the configured search space (503). After the terminal decodes the DCI, the terminal can transmit a beam report by including it in a physical uplink shared channel (PUSCH) in the resources indicated by the DCI. At this time, the beam report can include beam reports for N beams including at least one beam having a better L1-RSRP than the current beam. N can be set by the base station to the terminal. Alternatively, it can be a predefined value or a value that can be determined according to the terminal implementation.

[0217] Referring to mode B (510) of FIG. 5, operations 501 and 502 may be similar to operations 501 and 502 of mode A. The difference between mode B and mode A is that in mode B, the terminal may request beam reporting resources from the base station and transmit beam reports on periodic uplink resources (which may include at least one of PUSCH resources or PUCCH resources) rather than searching the search space for PDCCHs (505). For example, in mode B, if the terminal requests resources for beam reporting from the base station, the terminal may be configured with uplink resources periodically. The terminal may transmit beam reports by including them on the PUCCH or PUSCH in operation 505.

[0218] According to the conventional evaluation cycle in which the terminal measures and evaluates L1-RSRP, when a request from the upper layer is directed to the terminal, the terminal measures L1-RSRP from the set reference signal included in a specific set in the last evaluation cycle T Evaluate_CBD Threshold Q during ms in_LR You should be able to evaluate whether it is getting better. At this time, the evaluation period T Evaluate_CBDcan be defined as SSB-based measurements ([Table 12]) and CSI-RS-based measurements ([Table 13]) in FR2.

[0219]

[0220]

[0221] Evaluation cycle T in Table

[0012] and Table

[0013] Evaluate_CBD In , P is a coefficient associated with the measurement gap, and N is the receiver beam sweeping coefficient. P CBD is a coefficient related to dual connect or Scell ​​(secondary cell), and M CBD is a coefficient according to the band size of CSI-RS. T SSB or T CSI-RS refers to the period of the reference signal related to the evaluation period, and refers to the period of SSB or CSI-RS. Set q1 is a set containing the reference signal index of the candidate beam in the beam recovery procedure.

[0222] In the case of the conventional evaluation cycle, since the terminal only needs to compare the L1-RSRP measured from the reference signal set during the evaluation cycle with a constant threshold, even if multiple reference signals are set for the terminal, the terminal can apply the requirement for the evaluation cycle to a single reference signal. On the other hand, in UEIBM, since the terminal compares the quality of the 'current beam' (e.g., L1-RSRP) with the quality of the 'new beam', if an evaluation cycle that considers only a single reference signal is applied to UEIBM, there is a problem that the terminal cannot perform a correct evaluation. For example, if the period of the reference signal of the new beam is larger than the period of the reference signal of the current beam, and the evaluation cycle is related to the period of the reference signal of the current beam, a problem may occur in which the reference signal of the new beam required during the evaluation cycle is not included in the evaluation cycle. Therefore, if the conventional evaluation cycle is required for the terminal, beam quality measurement and comparison for both the 'current beam' and the 'new beam' may not be performed.

[0223] This disclosure presents a method for resolving the problem that beam quality measurements and comparisons for both the "current beam" and the "new beam" in UEIBM cannot be performed when a conventional evaluation cycle is required by the terminal. The methods described below are applicable not only to UEIBM, but also to general operations that involve measuring and evaluating multiple reference signals.

[0224] If the L1-RSRP of the new beam of the terminal is better than the current beam, the terminal can send a resource request for beam report to the base station. Alternatively, if M events (wherein, M can be a value that can be set by the base station to the terminal, a predefined value, or a value that can be determined according to the terminal implementation) occur within a time window set as an optional option, the terminal can send a resource request for beam report to the base station. The current beam and the new beam here can be the same as the current beam / new beam of the above-described operation 501. In this case, the terminal can include at least one of [Method 0], [Method 1], [Method 2], [Method 3], and [Method 4] for the requirement described below.

[0225] The above methods are described in more detail below.

[0226] Before a detailed explanation, the terms used in the following description of the present disclosure are defined. Hereinafter, a 'reference signal' may include at least one of an SSB and a CSI-RS. Hereinafter, 'QCLed' may mean that spatial parameters are related to each other. For example, 'beam A and QCLed reference signal' means a reference signal whose spatial parameters are related to a TCI state applying beam A. Hereinafter, an 'evaluation period' may mean a time period during which a terminal can derive an evaluation result based on a value measured within the evaluation period. Hereinafter, a 'measurement period' may mean a time period during which a terminal can measure a reference signal at one or more points in time included in the measurement period and derive a measurement result. A terminal may be required to derive a measurement result within an accuracy defined in a standard within the measurement period.

[0227] According to one embodiment of the present disclosure, in [Method 0], the terminal may expect that the periods of the current beam or the new beam and the QCLed reference signal are all the same. In this case, the terminal may be required to evaluate the current beam and the new beam during a conventional evaluation period.

[0228] According to one embodiment of the present disclosure, in [Method 1], the terminal can apply the largest period among the periods of the current beam and the QCL reference signal and the periods of the new beam and the QCL reference signals as the period of the reference signal related to the evaluation period.

[0229] FIG. 6A illustrates an example of a reference signal measurement and evaluation of a terminal according to an embodiment of the present disclosure. More specifically, FIG. 6A relates to an example of a reference signal measurement and evaluation of a terminal according to the aforementioned method 1. Referring to FIG. 6A, the terminal must measure and evaluate a current beam (601), a new beam 1 (602), and a new beam 2 (603) during an evaluation period (600). At this time, it can be assumed that the terminal is required to measure three samples. In FIG. 6A, the terminal can determine the evaluation period (600) by applying the largest new beam period 1 (602) among the current beam period (601), the new beam period 1 (602), and the new beam period 2 (603).

[0230] According to one embodiment of the present disclosure, in [Method 2], the terminal may apply the largest period among the periods of the current beam and the QCL reference signal and the periods of the new beam and the QCL reference signals as the period of the reference signal related to the evaluation period. In addition, the terminal may be required to measure and evaluate the most recent measurement points among the measurement points belonging to the evaluation period in order to derive the most recent measurement result within the evaluation period.

[0231] FIG. 6B illustrates an example of measuring and evaluating a reference signal of a terminal according to an embodiment of the present disclosure. More specifically, FIG. 6B relates to an example of measuring and evaluating a reference signal of a terminal according to the aforementioned method 2. Referring to FIG. 6B, the terminal must measure and evaluate the current beam (601), new beam 1 (602), and new beam 2 (603) during an evaluation period (600). At this time, it can be assumed that the terminal is required to measure three samples. In FIG. 6B, the terminal can determine the evaluation period (600) by applying the largest new beam period 1 (602) among the current beam period (601), new beam period 1 (602), and new beam period 2 (603). In addition, the terminal measures and evaluates the most recent measurement points (604, 605, 606) among the measurement points within the evaluation period (600). At this time, 604 may mean the most recent measurement time points of the current beam and the QCL reference signal among the measurement time points belonging to the evaluation period (600). 605 may mean the most recent measurement time points of the new beam 1 and the QCL reference signal among the measurement time points belonging to the evaluation period (600). 606 may mean the most recent measurement time points of the new beam 2 and the QCL reference signal among the measurement time points belonging to the evaluation period (600).

[0232] According to one embodiment of the present disclosure, in [Method 3], the terminal needs to satisfy both a requirement for a measurement period and a requirement for an evaluation period. During the measurement period, the terminal may be required to perform measurements on a given reference signal. During the evaluation period, the terminal may be required to perform an evaluation on the quality of the current beam and a new beam based on the measured values. The period related to the evaluation period may include at least one of a value fixed in the standard, a value set in a higher layer (e.g., RRC), or a measurement period of the current beam and the QCLed reference signal. If the measurement period is longer than the evaluation period, the period during which the terminal performs the evaluation may include at least one of the following alternatives.

[0233] - Alternative 1: The terminal can use the values ​​measured during the most recent measurement cycle before the end of the evaluation cycle for evaluation. In other words, the terminal can derive evaluations of the current beam and the new beam at the end of the evaluation cycle.

[0234] - Alternative 2: The terminal can use the values ​​measured during the measurement period, which includes the measurement time of the reference signal existing within the evaluation period and the measurement time after the end of the evaluation period, for evaluation. In other words, the terminal can complete the evaluation of the current beam and the new beam at the end of the measurement period of the reference signal. At this time, if there are multiple reference signals with measurement periods greater than the evaluation period, the evaluation of the current beam and the new beam can be derived at the end of the measurement period of the reference signal with the largest period.

[0235] FIG. 7 illustrates an example of measuring and evaluating a reference signal of a terminal according to an embodiment of the present disclosure. More specifically, FIG. 7 relates to an example of measuring and evaluating a reference signal of a terminal according to the aforementioned method 3. Referring to FIG. 7, the terminal must measure and evaluate the current beam (701), new beam 1 (702), and new beam 2 (703) during an evaluation period (700). At this time, it can be assumed that the terminal is required to measure three samples. In FIG. 7, the terminal can determine the evaluation period (700) using at least one of a value fixed in the standard, a value set in a higher layer (e.g., RRC), or a measurement period of the current beam and the QCLed reference signal. The terminal can determine the measurement periods by applying the current beam period (701), new beam period 1 (702), and new beam period 2 (703), respectively. Referring to FIG. 7, the measurement periods (704, 705) of new beam period 1 are longer than the evaluation period (700). That is, in the example of FIG. 7, the terminal may be required to measure three samples, and in the case of the new beam 1, it can be seen that the length of time required to measure the new beam 1 and three QCL reference signals is greater than the evaluation period (700). On the other hand, in the case of the current beam and the new beam 2, it can be seen that the length of time required for the terminal to measure three samples is shorter than the evaluation period (700). At this time, if the terminal applies the aforementioned alternative 1, it can measure and evaluate the new beam 1 and the QCL reference signal during 704. If the terminal applies alternative 2, it can measure and evaluate the new beam 1 and the QCL reference signal during 705.

[0236] According to one embodiment of the present disclosure, in [Method 4], the terminal may be required to perform evaluation at least once before the periodic PUCCH time point (502) at the latest. The specific measurement time point may be determined depending on the terminal implementation. According to another embodiment of the present disclosure, the terminal may be required to perform evaluation based on the measurement value of the reference signal measured during the most recent measurement period before the periodic PUCCH time point (502).

[0237] FIG. 8 illustrates an example of reference signal measurement and evaluation of a terminal according to an embodiment of the present disclosure. More specifically, FIG. 8 relates to an example of reference signal measurement and evaluation of a terminal according to the aforementioned method 4. Referring to FIG. 8, a terminal may be required to evaluate a current beam having a period of 801, a new beam 1 having a period of 802, and a new beam 2 having a period of 803 at least once before a periodic PUCCH point (800). At this time, the terminal may complete the evaluation before the periodic PUCCH point (800) and determine whether to transmit the PUCCH. In addition, assuming that the terminal is required to measure three samples in FIG. 8, the terminal may be required to evaluate reference signals QCLed with the current beam, the new beam 1, and the new beam 2 at the most recent measurement periods 805, 806, and 807 before the periodic PUCCH point (800), respectively. The terminal can complete evaluation before the periodic PUCCH time point (800) and determine whether to transmit PUCCH.

[0238] The terminal sets the worst / best measurement values ​​(e.g., L1-RSRP) of the activated TCI states as a threshold, and if the quality of at least one new beam is better than the threshold, the terminal can transmit a resource request (502) for beam reporting to the base station. Here, the activated TCI states may be some TCI states activated through MAC-CE among the list of TCI states configured for the PDSCH (physical downlink shared channel). The maximum number of TCI states that can be activated is 8, and the number of TCI states actually activated for the terminal can be determined according to the capability report of the terminal. In this case, the terminal can include at least one of [Method 5] and [Method 6] for the requirement.

[0239] According to one embodiment of the present disclosure, in [Method 5], an update period and an evaluation period may be included within the evaluation cycle of the terminal. During the update period, the terminal may measure activated TCI states and a QCL reference signal to update the lowest / highest measurement values. If the lowest / highest measurement values ​​persist without a valid time, a problem may arise in which the lowest / highest measurement values ​​do not reflect the terminal environment. Therefore, the terminal needs to be configured with an expiration window or an expiration timer, and interpret the lowest / highest measurement values ​​as valid only within the window or if the timer has not expired. When the next window ends or the timer expires, the terminal may discard the existing lowest / highest measurement values ​​and update the new lowest / highest measurement values. Thereafter, the terminal may start a new window or restart the timer. During the evaluation period, the terminal may be required to evaluate a new beam and a QCL reference signal. At this time, the terminal may not expect new beam measurements and evaluations when updating the minimum / maximum measurements of the activated TCI states. Conversely, the terminal may not expect new beam measurements and evaluations when performing new beam measurements and evaluations.

[0240] FIG. 9 illustrates an example of reference signal measurement and evaluation of a terminal according to one embodiment of the present disclosure. More specifically, FIG. 9 relates to an example of reference signal measurement and evaluation of a terminal according to the aforementioned method 5. The terminal may be required to perform a minimum / maximum measurement value update in an update interval (904) and a reference signal evaluation in an evaluation interval (905) within an evaluation period (900). The terminal may measure one or more activated TCI states and QCLed reference signals and perform a minimum / maximum measurement value update in the update interval (904). The update interval may include at least a measurement interval associated with the period (901) of the activated TCI state and the QCLed reference signal. The terminal may evaluate a new beam 1 and the QCLed reference signal and a new beam 2 and the QCLed reference signal in the evaluation interval (905). The evaluation interval may include a measurement interval associated with period 902 and a measurement interval associated with period 903.

[0241] According to one embodiment of the present disclosure, in [Method 6], the terminal can determine whether to apply [Method 5] based on the terminal capability report. The number of reference signals that the terminal can measure may be limited depending on the capability. For example, there may be a case where the terminal cannot measure multiple activated TCI states and QCL reference signals, and multiple new beams and QCL reference signals. If the terminal reports that simultaneous measurement is possible through the capability report, the terminal can measure activated TCI states and new beams simultaneously. In this case, simultaneous measurement by the terminal may include not only measuring different beams within the same OFDM symbol, but also a case where measurement periods related to different beams overlap with each other. In other words, rather than the update interval and the evaluation interval being included separately in the evaluation period as in Method 5, if the terminal can perform simultaneous measurement according to Method 6, all or part of the update interval and the evaluation interval may be included in the evaluation period in a temporally overlapping form. Furthermore, the terminal needs to be configured with an expiration window or an expiration timer, and interpret the lowest / highest measurements as valid only within the window or when the timer has not expired. When the next window ends or the timer expires, the terminal can discard the existing lowest / highest measurements and update the new lowest / highest measurements. Afterwards, the terminal can start a new window or restart the timer. If the terminal does not report the capability of simultaneous measurements through the capability report or reports that it cannot, the terminal can apply [Method 5].

[0242] FIG. 10 is a block diagram illustrating the functional structure of a terminal in a wireless communication system according to an embodiment of the present disclosure.

[0243] Referring to FIG. 10, the terminal may include a terminal receiving unit (1000), a terminal transmitting unit (1010), and a terminal processing unit (control unit) (1005).

[0244] The terminal receiving unit (1000) and the terminal transmitting unit (1010) may be collectively referred to as a transceiver. Depending on the communication method of the terminal described above, the terminal receiving unit (1000), the terminal transmitting unit (1010), and the terminal processing unit (1005) 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 (e.g., memory, etc.) than the components described above. In addition, the terminal receiving unit (1000), the terminal transmitting unit (1010), and the terminal processing unit (1005) may be implemented in the form of a single chip.

[0245] The terminal receiving unit (1000) and the terminal transmitting unit (1010) (or, transmitting and receiving unit) can transmit and receive signals with a base station. Here, the signals can include control information and data. To this end, the transmitting and receiving unit can 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 frequency-converts a received signal. However, this is only one embodiment of the transmitting and receiving unit, and the components of the transmitting and receiving unit are not limited to the RF transmitter and RF receiver.

[0246] In addition, the transceiver can receive a signal through a wireless channel and output it to the terminal processing unit (1005), and transmit a signal output from the terminal processing unit (1005) through the wireless channel.

[0247] Memory (not shown) can store programs and data necessary for the operation of the terminal. Furthermore, the memory can store control information or data included in signals acquired from the terminal. The memory may be comprised of a storage medium, such as ROM, RAM, a hard disk, CD-ROM, or DVD, or a combination of such storage media.

[0248] The terminal processing unit (1005) can control a series of processes so that the terminal can operate according to the embodiments of the present disclosure described above. The terminal processing unit (1005) can be implemented as a control unit or one or more processors.

[0249] FIG. 11 is a block diagram illustrating the structure of a base station in a wireless communication system according to an embodiment of the present disclosure.

[0250] Referring to FIG. 11, the base station may include a base station receiving unit (1100), a base station transmitting unit (1110), and a base station processing unit (control unit) (1105).

[0251] The base station receiving unit (1100) and the base station transmitting unit (1110) may be collectively referred to as a transceiver. Depending on the communication method of the base station described above, the base station receiving unit (1100), the base station transmitting unit (1110), and the base station processing unit (1105) 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 (e.g., memory, etc.) than the components described above. In addition, the base station receiving unit (1100), the base station transmitting unit (1110), and the base station processing unit (1105) may be implemented in the form of a single chip.

[0252] The base station receiving unit (1100) and the base station transmitting unit (1110) (or, transmitting and receiving unit) can transmit and receive signals with the terminal. Here, the signals can include control information and data. To this end, the transmitting and receiving unit can 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 frequency-converts a received signal. However, this is only one embodiment of the transmitting and receiving unit, and the components of the transmitting and receiving unit are not limited to the RF transmitter and RF receiver.

[0253] In addition, the transceiver can receive a signal through a wireless channel and output it to the base station processing unit (1105), and transmit the signal output from the base station processing unit (1105) through the wireless channel.

[0254] Memory (not shown) can store programs and data necessary for the operation of the base station. Furthermore, the memory can store control information or data contained in signals acquired from the base station. The memory may be comprised of a storage medium, such as ROM, RAM, a hard disk, CD-ROM, or DVD, or a combination of such storage media.

[0255] The base station processing unit (1105) can control a series of processes so that the base station can operate according to the embodiments of the present disclosure described above. The base station processing unit (1105) can be implemented as a control unit or one or more processors.

[0256] 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.

[0257] 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.

[0258] 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 of the disclosure.

[0259] Additionally, although not disclosed in the present disclosure, a method in which a separate table or information including at least one component included in the table proposed in the present disclosure is used is also possible.

[0260] Meanwhile, the embodiments of the present disclosure disclosed in this disclosure and the drawings are merely specific examples presented to easily explain the technical content of the present disclosure and aid in understanding of 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 examples based on the technical concepts of the present disclosure are possible. Furthermore, the above-described embodiments can be combined and operated as needed.

Claims

1. In a method performed by a terminal (user equipment, UE) in a wireless communication system, A step of obtaining periodic information for at least one new beam different from the current beam; A step of determining an evaluation period for the at least one new beam based on the period information; Within the evaluation period, measuring a first signal received through the current beam and a second signal received through the at least one new beam; and A method comprising the step of transmitting a message to a base station for reporting the results of the above measurement.

2. In paragraph 1, The above evaluation cycle is, It is determined based on the largest period among the first measurement period of the current beam and the second measurement period according to the period information, The above measuring steps are: A method further comprising the step of measuring a first number of samples, the number of which is required for evaluating the beam.

3. In paragraph 2, The above measuring steps are: A method further comprising the step of measuring the first number of samples, which is the number required for evaluating the beam, in reverse order from the time point at which the evaluation cycle ends.

4. In paragraph 1, The above evaluation cycle is, A method wherein the PUCCH (physical uplink control channel) for requesting resources of the message for reporting the results of the above measurement is terminated before transmission.

5. In paragraph 1, The above method, Further comprising a step of comparing a first L1-RSRP (layer 1 reference signal received power) of the first signal and a second L1-RSRP of the second signal, The above evaluation cycle is, Includes update and evaluation sections. The above first signal is, A method, wherein the update interval is measured prior to the evaluation interval.

6. In paragraph 5, The above comparing steps are: A method further comprising the step of comparing the average value of the first L1-RSRP with the second L1-RSRP.

7. In paragraph 5, The above comparing steps are: A method further comprising the step of comparing the highest or lowest measured value of the first L1-RSRP with the second L1-RSRP.

8. In the terminal (user equipment, UE), At least one transceiver; At least one processor communicatively coupled to said at least one transceiver; and At least one memory communicatively coupled to said at least one processor and storing instructions, The above instructions are executed individually or in any combination by the at least one processor, so that the terminal: Obtain periodic information for at least one new beam different from the current beam, Determine an evaluation period for the at least one new beam based on the above periodic information, Within the above evaluation period, measuring a first signal received through the current beam and a second signal received through the at least one new beam, A terminal that transmits a message to the base station to report the results of the above measurement.

9. In paragraph 8, The above evaluation cycle is, It is determined based on the largest period among the first measurement period of the current beam and the second measurement period according to the period information, The above commands cause the terminal to: A terminal configured to measure a first number of samples, which is the number required for evaluating a beam.

10. In paragraph 9, The above commands cause the terminal to: A terminal configured to measure the first number of samples required for beam evaluation in reverse order from the time point at which the above evaluation cycle ends.

11. In paragraph 8, The above evaluation cycle is, A terminal that is terminated before a PUCCH (physical uplink control channel) is transmitted to request resources of the message for reporting the results of the above measurement.

12. In paragraph 8, The above commands cause the terminal to compare the first L1-RSRP (layer 1 reference signal received power) of the first signal with the second L1-RSRP of the second signal, The above evaluation cycle is, Includes update and evaluation sections. The above first signal is, A terminal measured in the update section preceding the evaluation section.

13. In paragraph 12, The above commands are used by the terminal A terminal that compares the average value of the first L1-RSRP with the second L1-RSRP.

14. In paragraph 12, The above commands cause the terminal to compare the highest or lowest measured value of the first L1-RSRP with the second L1-RSRP.

15. One or more non-transitory computer-readable storage media storing computer-executable instructions, wherein when the computer-executable instructions are individually or collectively executed by at least one processor of a user equipment (UE), the UE: Obtain periodic information for at least one new beam different from the current beam, Determine an evaluation period for the at least one new beam based on the above periodic information, Within the above evaluation period, measuring a first signal received through the current beam and a second signal received through the at least one new beam, A recording medium that transmits a message to a base station to report the results of the above measurement.

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