Method and apparatus for reporting measurement beam in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. According to various embodiments of the present disclosure, a method performed by user equipment (UE) may comprise the steps of: identifying a result in which reference signal received power (RSRP) of a second beam is measured to be greater than RSRP of a first beam; transmitting, to a base station, a layer 1 (L1) indication for the result; and transmitting, to the base station, a physical uplink control channel (PUCCH) for UE initiated beam measurement (UEIBM) triggering, wherein the RSRP of the first beam may be acquired according to a first measurement without applying a beam sweeping coefficient.

Description

Method and device for reporting a measurement beam in a wireless communication system

[0001] The present disclosure relates generally to a wireless communication system, and more particularly, to a method and apparatus for a terminal to report a beam 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] As described above and with the development of mobile communication systems, various services have become available, and methods for providing these services effectively are required.

[0009] Based on the discussion described above, the present disclosure provides a method and device for a terminal to report a beam in a wireless communication system, and more specifically, provides a method and device for a beam reporting procedure depending on whether beam sweeping is performed.

[0010] The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0011] According to various embodiments of the present disclosure, a method performed by a user equipment (UE) may include: identifying a result in which a reference signal received power (RSRP) of a second beam is measured to be greater than a reference signal received power (RSRP) of a first beam; transmitting, to a base station, an L1 (layer 1) indication of the result; and transmitting, to the base station, a physical uplink control channel (PUCCH) for UE initiated beam measurement (UEIBM) triggering, wherein the RSRP of the first beam may be obtained according to a first measurement without applying a beam sweeping coefficient.

[0012] 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: identify a result in which an RSRP of a second beam is measured to be greater than an RSRP of a first beam; transmit an L1 (layer 1) indication of the result to a base station; and transmit a PUCCH (physical uplink control channel) for UEIBM (UE initiated beam measurement) triggering to the base station, wherein the RSRP of the first beam may be obtained according to a first measurement without applying a beam sweeping coefficient.

[0013] The present disclosure provides a device and method that can reduce the burden of changing the beam at a receiving end by providing a method for a terminal to report a beam in a wireless communication system.

[0014] According to an embodiment of the present disclosure, a device and method for effectively providing a service in a wireless communication system can be provided.

[0015] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0016] 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.

[0017] FIG. 2 illustrates a time domain mapping structure and beam sweeping operation of a synchronization signal according to one embodiment of the present disclosure.

[0018] FIG. 3 illustrates a signal flow for random access (RA) according to one embodiment of the present disclosure.

[0019] 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.

[0020] FIG. 5 illustrates an example of a terminal-initiated beam reporting procedure according to one embodiment of the present disclosure.

[0021] FIG. 6 illustrates an example of a terminal-initiated beam reporting procedure that simplifies beam sweeping according to one embodiment of the present disclosure.

[0022] FIG. 7 illustrates an example of a terminal-initiated beam reporting procedure that simplifies beam sweeping in Mode A according to one embodiment of the present disclosure.

[0023] FIG. 8 illustrates an example of a terminal-initiated beam reporting procedure that simplifies beam sweeping in Mode B according to one embodiment of the present disclosure.

[0024] FIG. 9 is a block diagram illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0025] FIG. 10 is a block diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0026] 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.

[0027] 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 ensure that the gist of this disclosure is conveyed more clearly without obscuring it by omitting unnecessary explanations.

[0028] 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.

[0029] 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 specification.

[0030] 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).

[0031] 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.

[0032] 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.

[0033] 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.

[0034] The terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, and terms referring to various identification information are provided as examples for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects with equivalent technical meanings may be used.

[0035] In the following description, the terms "physical channel" and "signal" may be used interchangeably with data or control signals. For example, while the term "physical downlink shared channel" (PDSCH) refers to a physical channel through which data is transmitted, the term "PDSCH" may also be used to refer to data. For example, 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."

[0036] 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).

[0037] 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.

[0038] 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.

[0039] 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 eMBB (enhanced Mobile BroadBand) services to improve existing voice / data communications, ultra-reliable and low latency communication (URLLC) services, and massive MTC (machine type communication) services that support large-scale machine-type communication.

[0040] 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.

[0041] Ultra-high frequency radio waves, sometimes called millimeter waves (mmWave), have wavelengths on the order of millimeters. However, in ultra-high frequency bands, path loss increases proportionally to the frequency band, reducing the coverage of mobile communication systems.

[0042] 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.

[0043] 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.

[0044] Figure 1 illustrates the basic structure of a time-frequency resource domain in a wireless communication system.

[0045] 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.

[0046] 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 grouped to form a subframe (105). The length of the subframe is 1.0 ms, and 10 subframes can be grouped 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.

[0047] 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.

[0048] 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.

[0049] 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 =12. Extended CP is applied to systems with relatively long transmission distances compared to regular CP, allowing for maintaining orthogonality between symbols. In the case of regular CP, the ratio of CP length to symbol length is maintained at a constant value, so 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.

[0050] 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 can support relatively larger cells. In mobile communications, the concept of a cell can include the area covered by a single base station.

[0051] 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.

[0052] [Table 1] below shows the relationship between the subcarrier spacing configuration (μ), subcarrier spacing (Δf), and CP length supported in the 5G system.

[0053] μΔf=2 μ ·15 [kHz]Cyclic prefix015Normal130Normal260Normal, Extended3120Normal4240Normal

[0054] [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.

[0055] μ 01410111420221440431480841416016

[0056] [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.

[0057] μ 212404

[0058] In the early days of 5G systems, 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 could 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).

[0059] 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.

[0060] 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.

[0061] 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 phase noise recovery 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.

[0062] 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.

[0063] According to one embodiment, in the initial access phase when a terminal first accesses a 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, common control information for various physical channels, etc.

[0064] In one embodiment, a synchronization signal serves as a reference signal for cell search, and subcarrier spacing may be applied for each frequency band to suit channel environments such as phase noise. In the case of a data channel or a control channel, the subcarrier spacing may be adaptively applied depending on the service type to support various services as described above.

[0065] Figure 2 illustrates the time domain mapping structure and beam sweeping operation of a synchronization signal.

[0066] Hereinafter, the following components may be predefined for the purpose of explaining the present disclosure.

[0067] - PSS (primary synchronization signal): A signal that serves as the basis for DL ​​time / frequency synchronization and can provide some cell ID information.

[0068] - 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.

[0069] - 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.

[0070] - 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.

[0071] 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).

[0072] In one embodiment, in addition to the initial connection procedure, the terminal may receive an SS / PBCH block to determine whether the radio link quality of the current cell is maintained at a certain level or higher. Furthermore, during a handover procedure in which the terminal moves from the current cell to a neighboring cell, the terminal may receive an SS / PBCH block of the neighboring cell to determine the radio link quality of the neighboring cell and obtain time / frequency synchronization with the neighboring cell.

[0073] In one embodiment, after the terminal acquires MIB and system information from the base station through an initial access procedure, the terminal may perform a random access procedure to transition the link with the base station to a connected state (or RRC_CONNECTED state). Upon completion of the random access procedure, the terminal transitions to a connected state (or RRC_CONNECTED state), enabling one-to-one communication between the base station and the terminal. The random access procedure will be described in detail below with reference to FIG. 3.

[0074] Figure 3 illustrates the flow of signals for random access (RA).

[0075] 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.

[0076] 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 uplink resources and power control commands to be used by the terminal to the terminal as scheduling information. The scheduling information transmitted by the base station may include control information for the uplink transmission beam of the terminal.

[0077] 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), the terminal may proceed to step (310) again. If proceeding to step (310) again, the terminal may increase the probability of the base station receiving the random access preamble by transmitting the random access preamble with the transmission power increased by a predetermined step (e.g., power ramping).

[0078] In step (330), the terminal may transmit uplink data including its terminal ID (e.g., message 3) to the base station using the uplink resources allocated in step (320). The terminal may 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 in consideration of 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.

[0079] In step (340), if the base station determines that the terminal has performed random access without collision with other terminals, the base station may transmit data (e.g., 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, the terminal may determine that the random access has been successful. The terminal may transmit HARQ-ACK (hybrid automatic repeat request acknowledgment) information indicating whether message 4 has been successfully received to the base station through an uplink control channel (physical uplink control channel, PUCCH).

[0080] 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).

[0081] According to one embodiment, when a terminal successfully completes a random access procedure, the terminal may transition to a connected state (or RRC_CONNECTED state), and one-to-one communication may be enabled between the base station and the terminal. The base station may receive terminal capability (UE) information from the terminal in the connected state (or RRC_CONNECTED state) and adjust scheduling by referring to the terminal capability (UE) information of the corresponding terminal. Through the UE capability information, the terminal may inform the base station of whether the terminal itself supports a certain function, the maximum allowable value of the function supported by the terminal, etc. Accordingly, the UE capability information reported by each terminal to the base station may have different values ​​for each terminal.

[0082] According to various embodiments, a terminal may report terminal capability information including at least one of the following control information to a base station.

[0083] - Control information related to frequency bands supported by the terminal

[0084] - Control information related to channel bandwidth supported by the terminal

[0085] - Control information related to the maximum modulation method supported by the terminal

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

[0087] - Control information related to the maximum number of layers supported by the terminal

[0088] - Control information related to CSI (channel state information) reporting supported by the terminal

[0089] - Control information on whether the terminal supports frequency hopping

[0090] - Bandwidth-related control information when supporting carrier aggregation (CA)

[0091] - Control information on whether cross carrier scheduling is supported when carrier aggregation is supported.

[0092] Figure 4 illustrates the flow of signals for a terminal to report terminal capability information to a base station.

[0093] 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).

[0094] According to various embodiments, 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 may be in the RRC_IDLE state. A terminal in the RRC_IDLE state may perform the following process.

[0095] - Performs terminal-specific DRX (discontinuous reception) cycles set by the upper layer.

[0096] - Receive paging messages from the core network

[0097] - Obtain system information

[0098] - Measurement actions related to serving cells (or camping cells) and cell selection / reselection

[0099] - Measurement operations related to surrounding cells and cell reselection

[0100] According to various embodiments, measurement operations and cell selection / reselection related to a serving cell (or a camping cell) are described in detail below (e.g., may be referred to as MR (main radio) RRM (radio resource management) measurement / evaluation in the present disclosure). According to one embodiment, the UE may measure synchronization signal-reference signal received power (SS-RSRP) and synchronization signal-reference signal received quality (SS-RSRQ) levels for the serving cell (or the camping cell) at least every M1*N1 DRX cycle, and evaluate a 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 otherwise, M1=1.

[0101] N1 can be determined by the following [Table 4].

[0102] DRX cycle[s]N1Nserv [number of DRX cycles]FR1FR2-1FR2-20.321812M1*N1*40.6458M1*N1*41.2846N1*22.5635N1*2

[0103] According to one embodiment, the cell selection decision criterion S may be satisfied when S_rxlev > 0 corresponding to SS-RSRP and S_qual > 0 corresponding to SS-RSRQ.

[0104]

[0105] Referring to mathematical expression 1, Q rxlevmeas is the measured SS-RSRP, and Q qualmeas is the measured SS-RSRQ. Q rxlevmin is the minimum required reception signal level in the serving cell and can be transmitted to the terminal through system information. Q qualmin is the quality level of the received signal required at the minimum limit in the serving cell and can be transmitted to the UE through the system information. The remaining parameters are presented in 3GPP TS 38.304. The UE can determine the SS-RSRP of the serving cell by filtering from at least two measurements that are spaced apart by at least half a DRX cycle in determining the measured SS-RSRP. In addition, the UE can determine the SS-RSRQ of the serving cell by filtering from at least two measurements that are spaced apart by at least half a DRX cycle in determining the measured SS-RSRQ.

[0106] According to various embodiments, the measurement operation related to the surrounding cells and cell reselection are described in detail below. The terminal 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] According to one embodiment, the 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 needs to search for the corresponding frequency layer cell at least every Thigher_prioirty_search. If the UE is N serv If the serving cell does not satisfy the cell selection criterion S during consecutive DRX cycles and the network has set inter-frequency layers of lower, higher priority, the terminal can search for lower, same, and higher frequency layer cells as in the measurement cycle described below.

[0108] According to one embodiment, the terminal initiates measurement of 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] According to one embodiment, the cell reselection decision criteria are calculated by the following parameters: R s , R n You can determine the cell selection order based on . For example, R s , R n The cell ranking can be determined 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] According to one embodiment, when a specific condition is satisfied with respect to the peripheral cell measurement, the peripheral cell measurement is stopped or the T measure It is possible to perform neighboring 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] According to various embodiments, a new terminal state called RRC_INACTIVE has been defined in 5G systems to reduce the energy and time consumed by a terminal during initial access. According to one embodiment, an RRC_INACTIVE terminal may perform the following processes in addition to the operations performed by an RRC_IDLE terminal.

[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] According to one embodiment, a terminal in an RRC_CONNECTED state may change from an RRC_CONNECTED state to an RRC_INACTIVE or RRC_IDLE state by receiving an RRC Release instruction from a base station.

[0120] According to one embodiment, a terminal in RRC_INACITVE, RRC_IDLE state may change from RRC_INACTIVE, RRC_IDLE to RRC_CONNECTED state by performing random access and completing all random access procedures.

[0121] According to various embodiments, based on the transmission and reception process of terminal capability information, a terminal connected to a base station can perform one-to-one communication with the base station as a terminal in the RRC_CONNECTED state. According to one embodiment, a terminal in the RRC_CONNECTED state can perform the following operations.

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

[0123] - Radio link monitoring

[0124] - Beam failure detection and beam failure recovery

[0125] According to various embodiments, first, monitoring of a downlink control channel of a terminal in an RRC_CONNECTED state is specifically described. If DRX (Discontinuous Reception) is not configured from a base station, a medium access control (MAC) entity of the terminal can continuously monitor a 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 received parameters. In the present disclosure, the terminal in the RRC_CONNECTED state monitoring the PDCCH with DRX may be referred to as performing a C-DRX (CONNECTED-DRX) operation.

[0126] According to one embodiment, radio link monitoring of a terminal in an RRC_CONNECTED state is described in detail below. The terminal can perform radio link monitoring for a serving cell (or primary serving cell (primary cell) when carrier aggregation is configured) (e.g., Pcell) using a channel state information-reference signal (CSI-RS) or an SS / PBCH signal. Performing radio link monitoring may include the terminal measuring the quality of the radio link using the signals and determining whether the radio link is in-sync or out-of-sync. Whether to perform radio link monitoring using the CSI-RS or the SS / PBCH signal can be configured by receiving an upper layer signal from a base station.

[0127] According to various embodiments, when measuring the quality of a radio link, an evaluation period for measuring and evaluating whether the link is in-sync or out-of-sync is specifically described. The in-sync evaluation period and the out-of-sync evaluation period may be determined differently depending on whether DRX is configured for PDCCH monitoring from a base station and (if DRX is configured) the DRX cycle value.

[0128] According to one embodiment, as a result of measurement and evaluation, an indication period is described for which a physical layer of a terminal transmits the evaluated in-sync or out-of-sync to a higher layer of the terminal. If DRX is not configured, the indication period may be determined as a maximum value between the shortest period of resources for radio link monitoring and 10 ms. Conversely, if DRX is configured, the indication period may be determined as a maximum value between the shortest period of resources for radio link monitoring and the DRX period.

[0129] In one embodiment, in-sync is described. For any resources in a resource set for radio link monitoring, if the radio link quality is better than a threshold value Q_in received from the configuration of the base station, the physical layer of the terminal may transmit in-sync to the upper layer of the terminal in a frame in which the radio link quality is evaluated. To determine in-sync of the radio link quality, the terminal may determine 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 may be, for example, 2%. The downlink control channel parameters may be determined differently depending on which signal is used to perform radio link monitoring.

[0130] In one embodiment, out-of-sync is described. If the radio link quality is worse than a threshold value Q_out received from the configuration of the base station for any resources in a resource set for radio link monitoring, the physical layer of the terminal may transmit an out-of-sync signal to the upper layer of the terminal in a frame in which the radio link quality is evaluated. In order to determine out-of-sync of the radio link quality, the terminal may determine whether the block error rate in the case of performing PDCCH decoding from virtual downlink control channel parameters is greater than a predefined value. The predefined value may be, for example, 10%. The downlink control channel parameters may be determined differently depending on which signal is used to perform radio link monitoring.

[0131] In one embodiment, the upper layer of the terminal (or the terminal) may start the T310 timer after receiving N310 consecutive out-of-syncs. If the terminal receives N311 consecutive in-syncs, the T310 timer may be stopped. Otherwise, the terminal may declare a Radio Link Failure (RLF) and start the T311 timer. The terminal may perform cell selection to find a suitable cell. If no suitable cell is found and the T311 timer expires, the terminal may transition to the RRC_IDLE state. If a suitable cell is found, the T311 timer may be stopped, and the terminal may transmit an RRC Reestablishment Request message to the base station of the cell and start the T301 timer. If the RRC Reestablishment operation is not successfully completed and the T301 timer expires, the terminal may transition to the RRC_IDLE state. If the RRC Reestablishment operation is successfully completed within the T301 timer, the terminal can transition to the normal RRC_CONNECTED state.

[0132] According to one embodiment, parameters and timers for performing procedures related to radio link monitoring and radio link failure, such as N310, T310 timer, N311, T311 timer, T301 timer, etc., may be set to the terminal by an upper signal from the base station.

[0133] According to various embodiments, beam failure detection (BFD) and beam failure recovery (BFR) of a terminal in an RRC_CONNECTED state are described in detail below. The terminal can perform beam failure detection for a serving cell using a CSI-RS or SS / PBCH signal. Performing beam failure detection may include measuring the quality of a beam using the above-described signals and determining whether the reception state of the beam is reliable (e.g., whether a virtual downlink control channel block error rate for the measured beam quality is less than a predefined value).

[0134] In one embodiment, a case where the reception status of a beam is unreliable (e.g., a virtual downlink control channel block error rate for the measured beam quality is equal to or greater than a predefined value) is defined as a beam failure instance. Whether to use a signal among the CSI-RS or the SS / PBCH signal to perform beam failure detection can be configured by receiving an upper layer signal from the base station. In order to determine the virtual downlink control channel block error rate, the terminal can determine whether the block error rate in the case of performing PDCCH decoding is greater than a predefined value from 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.

[0135] In one embodiment, when the number of beam failure instances increases by 1, a timer (beamFailureDetectionTimer) associated with the beam failure instances may be restarted. If the terminal (or the MAC layer of the terminal) does not detect any additional beam failure instances until the timer expires, the accumulated beam failure instances (BFI_COUNTER) may be reset.

[0136] According to one embodiment, 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) may trigger beam failure recovery. When beam failure recovery is triggered, the terminal (or the MAC layer of the terminal) may perform beam failure recovery by performing random access with the base station using resources or random access preambles set for the best candidate beam. The terminal may perform contention-free random access (contention-free random access, CFRA) using downlink control channel resources (control resource set, CORESET) and random access preambles set by the base station for beam failure recovery. If a collision-free random access fails, or there is no best candidate beam allocated for collision-free random access, or no collision-free random access resource or random access preamble is set, the terminal can perform a collision-prone random access (contention-based random access, CBRA) to recover from beam failure.

[0137] Below, a scheduling method for a base station to transmit downlink data to a terminal or instruct the terminal to transmit uplink data is specifically described.

[0138] According to one embodiment, downlink control information (DCI) may include control information transmitted by a base station to a terminal via the downlink. The 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 the DCI for each terminal and then transmits it to each terminal via a physical downlink control channel (PDCCH).

[0139] According to one embodiment, the base station may operate by applying a DCI format determined for a purpose, such as whether it is scheduling information for downlink data (downlink assignment), scheduling information for uplink data (uplink grant), or DCI for power control, for a terminal to be scheduled.

[0140] According to one embodiment, a base station may transmit downlink data to a terminal via a physical downlink shared channel (PDSCH), which is a physical channel for downlink data transmission. The base station may inform the terminal of scheduling information, such as a specific mapping location in the time and frequency domains of the PDSCH, a 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.

[0141] According to one embodiment, a terminal may transmit uplink data to a base station via a physical uplink shared channel (PUSCH), which is a physical channel for uplink data transmission. The base station may inform the terminal of scheduling information, such as a specific mapping location in the time and frequency domains of the PUSCH, a modulation scheme, HARQ-related control information, and power control information, through DCI related to uplink data scheduling information among the DCI transmitted via the PDCCH.

[0142] According to one embodiment, the time-frequency resources to which the PDCCH is mapped may be referred to as a control resource set (CORESET). The 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). The base station configuring a CORESET to the terminal may mean that the base station provides the terminal with information such as a CORESET identifier, a frequency location of the CORESET, and a 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.

[0143]

[0144] In one embodiment, CORESET operates 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] According to one embodiment, interleaved and non-interleaved transmission methods for PDCCH may be supported. The base station may configure whether interleaved or non-interleaved transmission is to be performed for each CORESET to the terminal through upper layer signaling. Interleaving may be performed in units of REG bundles. A REG bundle may be defined as a set of one or more REGs. The terminal may determine the CCE-to-REG mapping method in the corresponding CORESET based on whether interleaved or non-interleaved transmission is configured by the base station, as shown in [Table 6] below.

[0146]

[0147] According to one embodiment, the base station may inform the terminal of configuration information such as information about the symbol to which the PDCCH is mapped within a slot and the transmission period through signaling.

[0148] According to one embodiment, the search space of the PDCCH is described below. 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 to detect a signal without knowing information about the downlink control channel, and 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, and since there are various aggregation levels that form 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] In one embodiment, the search space may be classified into a common search space (CSS) and a UE-specific search space (USS). A certain group of UEs or all UEs may examine the common search space of the PDCCH to receive cell-common control information, such as dynamic scheduling for system information block (SIB) or paging messages. For example, a UE may receive scheduling allocation information for a PDSCH for receiving system information by examining 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 may be defined as a set of pre-arranged CCEs. UE-specific scheduling allocation information for a PDSCH or PUSCH may be received by the UE by examining the UE-specific search space of the PDCCH. The UE-specific search space may be defined UE-specifically as a function of the UE ID and various system parameters.

[0150] According to one embodiment, the base station may set configuration information for the search space of the PDCCH to the terminal through higher layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station may set the number of PDCCH candidates in 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 the 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] According to one embodiment, 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] In one embodiment, 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] According to one embodiment, a terminal may monitor the following combination of DCI formats and RNTIs in a common search space. 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] According to one embodiment, in a terminal-specific search space, a terminal may monitor the following combination 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] According to one embodiment, RNTIs may follow the following definitions and usages. 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] DCI formatUsage0_0Scheduling of PUSCH in one cell0_1Scheduling of PUSCH in one cell1_0Scheduling of PDSCH in one cell1_1Scheduling of PDSCH in one cell2_0Notifying a group of UEs of the slot format2_1Notifying a group of UEs of the PRB(s) and OFDM symbol(s) where UE may assume no transmission is intended for the UE2_2Transmission of TPC commands for PUCCH and PUSCH2_3Transmission of a group of TPC commands for SRS transmissions by one or more UEs

[0177] According to one embodiment, the search space of aggregation level L in CORESET p, a search space set s, can be expressed as in the following mathematical expression 2.

[0178] [Equation 2]

[0179]

[0180] - L: Integration level

[0181] - n CI : Carrier index

[0182] - N CCE,p : Total number of CCEs existing within the control resource set p

[0183] - n μ s,f : slot index

[0184] - M (L) p,s,max : Number of PDCCH candidates for aggregation level L

[0185] - m s,nCI =0, ..., M (L)p,s,max -1: PDCCH candidate index of aggregation level L

[0186] - i=0, ..., L-1

[0187] =(A p · )modD, Y p,-1 =n RNTI ≠0, A0=39827, A1=39829, A2=39839, D=65537

[0188] - n RNTI : Terminal identifier

[0189] The value can be 0 for a common search space.

[0190] In the case of a terminal-specific search space, the value may correspond to a value that changes according to the terminal's ID (C-RNTI or ID set to the terminal by the base station) and time index.

[0191] According to various embodiments, the CSI-RS is described in detail below. NR has a CSI framework for instructing a base station to measure and report channel state information (CSI) of a terminal. The NR CSI framework can be composed of at least two elements: a resource setting and a report setting, and the report setting can have a connection relationship with each other by referencing at least one ID of a resource setting.

[0192] 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 as shown in [Table 9] to convey information regarding resource settings.

[0193]

[0194] According to one embodiment, the signaling information CSI-ResourceConfig in [Table 9] may include information about each resource setting. According to the signaling information described above, each resource setting may include a resource setting index (csi-ResourceConfigId) or a BWP index (bwp-ID) or a time-domain transmission configuration (resourceType) of the resource 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 resource sets for channel measurement or a set including resource sets 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-RS resource or a synchronous / broadcast channel block (SS / PBCH block, SSB). If the resource set list is a set containing resource sets for interference measurement, each resource set may contain at least one interference measurement resource (CSI interference measurement, CSI-IM).

[0195] For example, if the resource set includes CSI-RS, the base station and the terminal can exchange signaling information such as [Table 10] to convey information about the resource set.

[0196]

[0197] According to one embodiment, the signaling information NZP-CSI-RS-ResourceSet in [Table 10] may include information about each resource set. According to the signaling information described above, each resource set includes at least information about a resource set index (nzp-CSI-ResourceSetId) or a set of indices of included CSI-RSs (nzp-CSI-RS-Resources), and may include part of information about a spatial domain transmission filter of included CSI-RS resources (repetition) or whether included CSI-RS resources are used for tracking (trs-Info).

[0198] In one embodiment, the CSI-RS may be the most representative reference signal included in a resource set. The base station and the terminal may exchange signaling information, as shown in [Table 11], to convey information regarding the CSI-RS resource.

[0199]

[0200] According to one embodiment, the signaling information NZP-CSI-RS-Resource in [Table 11] contains information about each CSI-RS. The information contained in the above-described signaling information NZP-CSI-RS-Resource may have the following meanings.

[0201] - nzp-CSI-RS-ResourceId: CSI-RS resource index

[0202] - resourceMapping: Resource mapping information for CSI-RS resources

[0203] - powerControlOffset: Ratio between PDSCH EPRE (Energy Per RE) and CSI-RS EPRE

[0204] - powerControlOffsetSS: Ratio between SS / PBCH block EPRE and CSI-RS EPRE

[0205] - scramblingID: scrambling index of the CSI-RS sequence

[0206] - periodicityAndOffset: Transmission period and slot offset of the CSI-RS resource

[0207] - qcl-InfoPeriodicCSI-RS: TCI-state information if the CSI-RS is a periodic CSI-RS.

[0208] The resourceMapping included in the above-described 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 12] below.

[0209]

[0210] According to one embodiment, [Table 12] shows the frequency resource density, CDM type, frequency axis and time axis start position of CSI-RS component RE pattern that can be set according to the number of CSI-RS ports (X). ), the number of frequency-axis REs (k') and the number of time-axis REs (l') of the CSI-RS component RE pattern may be indicated. The above-described 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 specified without limitation of subcarriers in a PRB (Physical Resource Block), and the CSI-RS RE position may be specified 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.

[0211] [Example 1: UE initiated beam reporting]

[0212] According to various embodiments of the present disclosure, according to a general beam management procedure of a terminal, a network may configure or activate periodic or semi-persistent beam reporting (e.g., N best beams and their corresponding L1-RSRP). In addition, the network may frequently trigger aperiodic beam reporting to the terminal to timely acquire the best / preferred beam for data transmission / control information transmission. However, frequently triggered beam reporting of the terminal may result in large uplink reporting and control signal overhead. If less frequent beam reporting is configured to the terminal to reduce the uplink reporting overhead and control signal overhead, the beam reporting by the terminal may not reflect the current status, so the network may not always be able to acquire the 'best / preferred' beam, which may lead to performance degradation. Given that terminals are better able to detect beam quality changes and timeliness than the network, terminal-initiated beam reporting procedures (e.g., when the terminal initiates the beam reporting procedure) can lead to more timely beam reporting while also reducing reporting overhead. For example, if the terminal determines that its current beam quality has deteriorated due to a terminal-initiated beam reporting procedure, the terminal can directly trigger a beam report without having to configure or trigger frequent reports through the network.

[0213] In one embodiment, a terminal may measure beam quality. The terminal may detect a deterioration in beam quality and notify a base station that the beam quality has deteriorated. The base station may receive a beam report request from the terminal, allocate resources for beam reporting to the terminal, and receive a beam report from the terminal. The UE-initiated beam reporting (UEIBM) procedure (or UE-initiated beam reporting) may be divided into Mode A and Mode B. Mode A and Mode B are merely exemplary names for indicating distinctly different operation modes, and the technical concepts described in the present disclosure are not limited by the terms.

[0214] FIG. 5 illustrates an example of a terminal-initiated beam reporting procedure according to one embodiment of the present disclosure.

[0215] According to one embodiment, referring to mode A (500) of FIG. 5, when UEIBM is set to a terminal, the terminal can initiate measurement and evaluation of the beam.

[0216] In step (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 may mean a reference signal that is quasi-co-located (QCL) with the indicated TCI state. Alternatively, the current beam may mean a reference signal that is QCLed with the indicated TCI state and a QCLed SSB.

[0217] In one embodiment, a definition of the current beam may be set for the terminal. For example, the terminal may be configured to interpret the current beam as meaning a reference signal that is quasi-co-located (QCL) with an indicated TCI state. Alternatively, the terminal may be configured to interpret the current beam as meaning a reference signal that is quasi-co-located with an indicated TCI state and a QCL-ed SSB.

[0218] In one embodiment, the new beam may refer to a reference signal established by higher 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.

[0219] In step (502), the terminal may transmit a resource request for beam reporting to the base station.

[0220] In one embodiment, if the L1-RSRP of the new beam is better than the L1-RSRP of the current beam (e.g., 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 for beam reporting to the base station.

[0221] According to one embodiment of the present disclosure, as an optional option, if M events occur within a set time window in which the L1-RSRP of a new beam is better than the L1-RSRP of a current beam (wherein M includes 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), the terminal can send a resource request for beam reporting to the base station. Here, the resource for beam reporting can be a resource that the terminal can use to perform beam reporting.

[0222] According to another embodiment of the present disclosure, the terminal may transmit a resource request for beam reporting to the base station when the quality of the current beam (e.g., L1-RSRP) is lower than a set threshold.

[0223] According to another embodiment of the present disclosure, the terminal may set the lowest L1-RSRP of the activated TCI states as a threshold value. If the L1-RSRP of at least one new beam is better than the threshold value, the terminal may transmit a resource request for beam reporting to the base station.

[0224] According to another embodiment of the present disclosure, the terminal may set the best L1-RSRP of the activated TCI states as a threshold value. If the L1-RSRP of at least one new beam is better than the threshold value, the terminal may transmit a resource request for beam reporting to the base station.

[0225] In one embodiment, the resource request may be transmitted to the base station via a periodically transmitted physical uplink control channel (PUCCH). Embodiments in which resource requests are triggered for beam reports from the terminal described above may be optionally used, and at least one of the above-described embodiments may be configured for the terminal by the base station.

[0226] In step (503), the terminal may receive DCI associated with a UL grant. More specifically, the terminal may detect a physical downlink control channel (PDCCH) including downlink control information (DCI) indicating beam reporting resources in the configured search space.

[0227] In step (504), after the terminal decodes the DCI, the terminal may transmit a beam report on a PUSCH (physical uplink shared channel) using the resources indicated by the DCI. At this time, the beam report may include beam reports for N beams, including at least one beam with a better L1-RSRP than the current beam. N may include a value that the base station may set for the terminal, a predefined value, or a value that may be determined according to the terminal implementation.

[0228] According to one embodiment, referring to Mode B (510) of FIG. 5, steps (501) and (502) may be similar to steps (501) and (502) of Mode A. The difference in Mode B compared to Mode A is that in Mode B, the terminal may request beam reporting resources from the base station and transmit beam reports in periodic uplink resources (which may include at least one of PUSCH resources or PUCCH resources) rather than searching the search space for PDCCH. For example, in Mode B, when the terminal requests resources for beam reporting from the base station, the terminal may be configured with periodic uplink resources. In step (505), the terminal may transmit the beam report by including it in the PUCCH or PUSCH.

[0229] [Example 2: UEIBM reporting requirement]

[0230] In general, in the conventional beam management procedure, when a request from an upper layer is directed to a terminal, the terminal measures and evaluates the L1-RSRP of a candidate beam according to the evaluation cycle, and the L1-RSRP measured from the set reference signal included in a specific set is determined by 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 cycle TEvaluate_CBD can be defined as SSB-based measurement [Table 13] and CSI-RS-based measurement [Table 14] in FR2.

[0231] [Table 13] illustrates the Evaluation period T_Evaluate_CBD_SSB for FR2.

[0232]

[0233] [Table 14] illustrates the Evaluation period T_Evaluate_CBD_CSI-RS for FR2.

[0234]

[0235] Evaluation cycle T in [Table 13] and [Table 14] Evaluate_CBD In , P is a coefficient associated with the measurement gap, and N is the receiver beam sweeping coefficient. N can have a value of 8 in the FR2-1 band and 12 in the FR2-2 band. P CBD is a coefficient related to dual connect or Scell ​​(secondary cell), and M CBD may mean 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 may refer to the period of SSB or CSI-RS. The set q1 may include the reference signal index of the candidate beam in the beam recovery procedure.

[0236] The terminal can compare the quality of the terminal's 'current beam' and the 'new beam', and if the 'new beam' has better quality than the 'current beam', it can trigger a beam report. According to a typical evaluation cycle, especially in the FR2 band, the terminal can have time to refine the receiver's beam by applying the Rx beam sweeping factor N. The terminal can identify an appropriate receiver beam based on the measured value while changing the receiver's beam. In the FR2 band, which is generally a millimeter wave band, beams formed from multiple antennas can be generated with a narrow width. Therefore, selecting an inappropriate receiver beam can cause a rapid performance degradation. Meanwhile, when the terminal is configured with UEIBM, it is assumed to be performed in parallel with the conventional beam management procedure. Therefore, the terminal can at least measure the current beam twice through the conventional beam management procedure and the UEIBM. Since the conventional beam management procedure has already provided the receiver's beam refinement time, the terminal can identify an appropriate receiver beam for the current beam. Therefore, it is reasonable to assume that the terminal knows the appropriate receiver beam for the current beam measured by UEIBM. If the terminal does not include beam refinement time in the evaluation cycle, not only can measurement and evaluation delays be reduced, but the burden of beam switching at the RF end of the receiver can also be reduced. Based on the above assumption, this disclosure specifically describes a method and requirements for allowing the terminal to exclude beam refinement time from the evaluation cycle.

[0237] According to various embodiments of the present disclosure, as described above, it can be assumed that the terminal knows the appropriate receiver beam for at least the current beam. If the terminal excludes the beam refinement process while evaluating the current beam and the new beam, the burden of beam changing at the RF end of the receiver can be reduced because beam changes are not required during the continuous evaluation process. On the other hand, since the new beam is established independently of the existing beam management procedure, there may be cases where measurement of the corresponding reference signal is not performed. Therefore, it cannot be assumed that the appropriate receiver beam is known for the new beam. Therefore, the terminal needs to refine the beam at least once for the new beam. If the terminal performs the beam refinement process once after the event occurs, the terminal will be able to know the appropriate receiver beam for the new beam. Furthermore, depending on the position of the beam refinement process, the overall measurement and evaluation time can be reduced, and the terminal can perform rapid beam reporting and beam management. Below, a UEIBM procedure that simplifies beam sweeping without including the beam refinement time is described in detail.

[0238] According to various embodiments of the present disclosure, a UEIBM procedure that simplifies beam sweeping without including time for the terminal to refine the beam in the evaluation cycle may include at least one of Case 1 and Case 2.

[0239] In one embodiment, according to Case 1, the terminal can perform evaluation without applying the beam sweeping coefficient. When an event occurs, the terminal can perform secondary measurement by applying the beam sweeping coefficient. By performing the secondary measurement, the terminal can obtain information about the receiver beam for a new beam that can be applied later. While the secondary measurement in Case 1 is not related to the evaluation result, the secondary measurement in Case 2 can affect the evaluation result.

[0240] In one embodiment, according to Case 2, the terminal may perform an evaluation without applying a beam sweeping coefficient. When an event occurs, the terminal may perform a secondary evaluation by applying a beam sweeping coefficient. If the secondary evaluation result does not meet the event occurrence conditions, the terminal may not trigger a beam report.

[0241] FIG. 6 illustrates an example of a terminal-initiated beam reporting procedure that simplifies beam sweeping according to one embodiment of the present disclosure.

[0242] Referring to Case 1 (600) of Fig. 6, in step (601), if the terminal has been set to UEIBM, the terminal can initiate measurement and evaluation of the beam. In step (601), the terminal may not apply a beam sweeping coefficient or may apply N=1.

[0243] In step (602), the terminal may determine whether an event has occurred. Here, the event may include at least one of: when the L1-RSRP of the new beam is better than that of the current beam; when M events occur within a set time window in which the L1-RSRP of the new beam is better than that of the current beam; when the quality of the current beam is lower than a set threshold; or when the quality of at least one new beam is better than the lowest / highest L1-RSRP of the activated TCI states. If the event has not occurred, the process may return to step (601). If the event has occurred, the process may proceed to step (603).

[0244] At step (603), the physical layer (layer 1) of the terminal may send an L1 indication to the upper layer. Thereafter, upon request from the upper layer, the terminal may proceed to step (604).

[0245] In step (604), the terminal may apply a beam sweeping coefficient and perform secondary measurements on the beam. The terminal may obtain time to refine the receiving end beam before transmitting the periodic PUCCH. The beam sweeping coefficient may include a fixed value in the standard or a value set in a higher layer.

[0246] In step (605), the terminal may transmit a resource request for beam reporting to the base station at the nearest periodic PUCCH time point after step (604).

[0247] An alternative to Case 1 (600) according to various embodiments of the present disclosure is described. Steps (601) and (602) may be identical to the conventional method. In step (603), the physical layer (layer 1) of the terminal needs to send an L1 indication to the upper layer. Thereafter, upon request from the upper layer, the terminal can transmit a periodic PUCCH, taking into account the terminal's processing time.

[0248] In step (604), the terminal may apply a beam sweeping coefficient and perform measurements on the secondary beam. The terminal may obtain time to refine the receiving end beam before transmitting the uplink channel. The beam sweeping coefficient may include a fixed value in the standard or a value set in a higher layer.

[0249] In step (605), the terminal can transmit a beam report to the base station on the nearest periodic uplink channel after step (604) is completed.

[0250] Referring to Case 2 (610) of Fig. 6, in step (601), if the terminal has been set to UEIBM, the terminal can initiate measurement and evaluation of the beam. In step (601), the terminal may not apply a beam sweeping coefficient or may apply N=1.

[0251] In step (602), the terminal may determine whether an event has occurred. Here, the event may include at least one of: when the L1-RSRP of the new beam is better than that of the current beam; when M events occur within a set time window in which the L1-RSRP of the new beam is better than that of the current beam; when the quality of the current beam is lower than a set threshold; or when the quality of at least one new beam is better than the lowest / highest L1-RSRP of the activated TCI states. If the event has not occurred, the process may return to step (601). If the event has occurred, the process may proceed to step (613).

[0252] In step (613), the terminal may apply a beam sweeping coefficient and perform a secondary evaluation of the beam. The beam sweeping coefficient may include a fixed value in the standard or a value set in a higher layer. If the evaluation result after applying the beam sweeping coefficient in step (613) satisfies the event occurrence condition, the terminal may proceed to step (614). If the event occurrence condition is not satisfied, the terminal may return to step (601).

[0253] At step (614), the physical layer (layer 1) of the terminal may send an L1 indication to the upper layer. Thereafter, upon request from the upper layer, the terminal may proceed to step (605).

[0254] In step (605), the terminal may transmit a resource request for beam reporting to the base station at the nearest periodic PUCCH time point after step (614) ends.

[0255] Hereinafter, various embodiments of the present disclosure will be described in detail when Case 1 and Case 2 are applied to Mode A and Mode B.

[0256] FIG. 7 illustrates an example of a terminal-initiated beam reporting procedure that simplifies beam sweeping in Mode A according to one embodiment of the present disclosure.

[0257] According to one embodiment, referring to Mode A Case 1 (700) of FIG. 7, in step (701), the terminal may not apply the beam sweeping coefficient. Alternatively, the terminal may perform measurement and evaluation on the reference signal QCLed to the current beam and the new beam, with N=1. If the event described above occurs in step (602) of FIG. 6 and a request (702) is generated from the upper layer of the terminal, the terminal needs to transmit a PUCCH (704) within the measurement period T1 (703) to which the beam sweeping coefficient is applied. For example, the terminal may be required to perform measurement by applying the beam sweeping coefficient within T1, and then transmit a beam report resource request (704) at the nearest PUCCH time point. In this case, T1 (703) can be expressed as in Mathematical Expression 3 below.

[0258]

[0259] - T pucch : The period of the set PUCCH (704)

[0260] - T Evaluation_period : Evaluation cycle applied at step 701

[0261] - D=2ms, terminal processing time

[0262] - N: Beam sweeping coefficient

[0263] According to one embodiment, referring to Mode A Case 2 (710) of FIG. 7, in step (701), the terminal may not apply the beam sweeping coefficient. Alternatively, the terminal may perform measurement and evaluation on the reference signal QCLed to the current beam and the new beam, with N = 1. If the event described above occurs (711) in step (602) of FIG. 6, the terminal may be requested to perform a secondary evaluation applying the beam sweeping coefficient during T1 (712). If the evaluation result performed in T1 (712) satisfies the event occurrence condition, the physical layer of the terminal needs to send an L1 instruction to the upper layer (713). Thereafter, according to the upper layer request (713), the terminal may perform T UEprocessing (714) may be required to transmit PUCCH (704). For example, the terminal may perform secondary evaluation by applying beam sweeping coefficients and transmit beam report resource request (704) at the nearest PUCCH time point after the terminal processing time. At this time, T1 (712) and T UEprocessing (714) can be expressed as mathematical equation 4 below.

[0264]

[0265] - T pucch : The period of the set PUCCH (704)

[0266] - T Evaluation_period : Evaluation cycle applied at step 701

[0267] - D=2ms, terminal processing time

[0268] - N: Beam sweeping coefficient

[0269] In one embodiment, in Mode B, the terminal may or may not be required to measure the reference signal between the beam report resource request and the beam report. If the terminal is not required to measure the reference signal, Cases 1 and 2 described in Mode A may be equally applicable to Mode B. If the terminal is required to measure the reference signal, only Case 1 among the Cases described in Mode A may be applicable to Mode B.

[0270] In one embodiment, the following description assumes that the terminal is required to measure a reference signal between a periodic PUCCH and a beam report requesting beam report resources in Mode B.

[0271] FIG. 8 illustrates an example of a terminal-initiated beam reporting procedure that simplifies beam sweeping in Mode B according to one embodiment of the present disclosure.

[0272] According to one embodiment, referring to Mode B Case1-1 (800) of FIG. 8, in step (801), the terminal may not apply a beam sweeping coefficient. Alternatively, the terminal may perform measurement and evaluation on a reference signal QCLed to the current beam and the new beam, with N=1. If the event described above occurs in step (602) of FIG. 6 and a request (802) is generated in the upper layer of the terminal, the terminal may be required to transmit a PUCCH (805) within T1 (803) considering the terminal processing time. After transmitting the PUCCH (805), the terminal may be required to transmit an uplink channel (806) within a measurement period T2 (804) to which the beam sweeping coefficient is applied. For example, when an event occurs, the terminal may transmit a beam report resource request (805) at the nearest PUCCH time point considering the terminal processing time, perform secondary measurement by applying a beam sweeping coefficient, and then transmit a beam report (806) at the nearest set uplink channel time point. At this time, T1 (803) and T2 (804) can be expressed as in the following mathematical expression 5.

[0273]

[0274] - T pucch : The period of the set PUCCH (805)

[0275] - T UL : The period of (806) of the set uplink channel

[0276] - T Evaluation_period : Evaluation cycle applied at step 801

[0277] - D=2ms, terminal processing time

[0278] - N: Beam sweeping coefficient

[0279] According to one embodiment, referring to Mode B Case1-2 (810) of FIG. 8, in step (801), the terminal may not apply a beam sweeping coefficient. Alternatively, the terminal may perform measurement and evaluation on a reference signal QCLed to the current beam and the new beam, with N=1. If the event described in step (602) of FIG. 6 occurs and a request (802) is generated in the upper layer of the terminal, the terminal may be required to transmit a PUCCH (805) within T1 (803) considering the terminal processing time. In parallel, if the event described in step (602) of FIG. 6 occurs and a request (802) is generated in the upper layer of the terminal, the terminal may be required to transmit an uplink channel (806) within a measurement period T2 (811) to which a beam sweeping coefficient is applied. For example, when an event occurs, the terminal may transmit a beam report resource request (805) at the nearest PUCCH time point considering the terminal processing time, and simultaneously perform a secondary measurement by applying a beam sweeping coefficient, and then transmit a beam report (806) at the nearest set uplink channel time point. At this time, T1 (803) and T2 (811) can be expressed as in the above-described mathematical expression 5.

[0280] FIG. 9 is a block diagram illustrating the functional structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0281] Referring to FIG. 9, the terminal may include a receiving unit (900), a transmitting unit (910), and a processing unit (control unit or controller) (905).

[0282] The receiving unit (900) and the transmitting unit (910) may be collectively referred to as a transceiver. Depending on the communication method of the terminal described above, the receiving unit (900), the transmitting unit (910), and the processing unit (905) 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 receiving unit (900), the transmitting unit (910), and the processing unit (905) may be implemented in the form of a single chip.

[0283] The receiving unit (900) and the transmitting unit (910) (or the transceiver) can transmit and receive signals with the base station. Here, the signals can include control information and data. To this end, the transceiver 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 transceiver, and the components of the transceiver are not limited to the RF transmitter and RF receiver.

[0284] In addition, the transceiver unit can receive a signal through a wireless channel and output it to the processing unit (905), and transmit the signal output from the processing unit (905) through the wireless channel.

[0285] 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.

[0286] The processing unit (905) can control a series of processes so that the terminal can operate according to the aforementioned embodiments of the present disclosure. The processing unit (905) can be implemented as a control unit or one or more processors.

[0287] FIG. 10 is a block diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0288] Referring to FIG. 10, the base station may include a receiving unit (1000), a transmitting unit (1010), and a processing unit (control unit or controller) (1005).

[0289] The receiving unit (1000) and the transmitting unit (1010) may be collectively referred to as a transceiver. Depending on the communication method of the base station described above, the receiving unit (1000), the transmitting unit (1010), and the processing unit (1005) 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 receiving unit (1000), the transmitting unit (1010), and the processing unit (1005) may be implemented in the form of a single chip.

[0290] The receiving unit (1000) and the transmitting unit (1010) (or the 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.

[0291] In addition, the transceiver unit can receive a signal through a wireless channel and output it to the processing unit (1005), and transmit the signal output from the processing unit (1005) through the wireless channel.

[0292] 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.

[0293] The processing unit (1005) can control a series of processes so that the base station can operate according to the aforementioned embodiments of the present disclosure. The processing unit (1005) can be implemented as a control unit or one or more processors.

[0294] 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.

[0295] 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.

[0296] 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 invention.

[0297] 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.

[0298] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples to easily explain the technical content of the present disclosure and facilitate 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 concept 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), A step of identifying a result in which the RSRP of the second beam is measured to be greater than the RSRP (reference signal received power) of the first beam; A step of transmitting an L1 (layer 1) indication of the result to the base station; and A step of transmitting a PUCCH (physical uplink control channel) for UEIBM (UE initiated beam measurement) triggering to the base station, A method wherein the RSRP of the first beam is obtained according to a first measurement without applying a beam sweeping coefficient.

2. In the first paragraph, the method, A method further comprising the step of performing a second measurement applying the beam sweeping coefficient to one or more beams associated with the second beam.

3. In the second paragraph, the second measurement is performed during a first time interval between transmission of the L1 indicator and transmission of the PUCCH.

4. In paragraph 2, The second measurement is performed during a first time interval between the first measurement and the transmission of the L1 indicator, and A method in which the above PUCCH is transmitted after a second time interval from the transmission of the L1 indicator.

5. In paragraph 1, The first beam is based on an activated transmission configuration indicator (TCI) state and a quasi-co-located (QCL) reference signal, and The above second beam is a method according to a reference signal set by upper layer signaling.

6. In the first paragraph, the method, A step of receiving DCI (downlink control information) associated with an UL (uplink) grant from the base station; and A method further comprising the step of transmitting a physical uplink shared channel (PUSCH) for reporting at least one beam including the second beam to the base station.

7. In the first paragraph, the method, Further comprising the step of transmitting a PUSCH for reporting at least one beam including the second beam to the base station, The above PUSCH is transmitted after the third time interval from the transmission of the L1 indicator.

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: Identify the result where the RSRP of the second beam is measured to be greater than the RSRP (reference signal received power) of the first beam, To the base station, transmit an L1 (layer 1) indication of the above result, and To the above base station, transmit a PUCCH (physical uplink control channel) for UEIBM (UE initiated beam measurement) triggering, The RSRP of the first beam is obtained by a terminal according to a first measurement without applying a beam sweeping coefficient.

9. In paragraph 8, the commands are: A terminal for performing a second measurement by applying the beam sweeping coefficient to one or more beams associated with the second beam.

10. In the 9th paragraph, the second measurement is performed during a first time interval between transmission of the L1 indicator and transmission of the PUCCH.

11. In paragraph 9, The second measurement is performed during a first time interval between the first measurement and the transmission of the L1 indicator, and The above PUCCH is a terminal transmitted after the second time interval from the transmission of the L1 indicator.

12. In paragraph 8, The first beam is based on an activated transmission configuration indicator (TCI) state and a quasi-co-located (QCL) reference signal, and The above second beam is a terminal according to a reference signal set by upper layer signaling.

13. In paragraph 8, the commands are: From the above base station, receive DCI (downlink control information) associated with an UL (uplink) grant, and A terminal that transmits a PUSCH (physical uplink shared channel) to the base station for reporting at least one beam including the second beam.

14. In paragraph 8, the commands are: To the base station, transmit a PUSCH for reporting at least one beam including the second beam, The above PUSCH is transmitted by a terminal after the third time interval from the transmission of the L1 indicator.

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