Method and device for UE request-based synchronization in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. This method performed by a user equipment (UE) comprises the steps of: receiving, from a base station, a discovery signal for a cell associated with the base station; on the basis of the discovery signal, transmitting, to the base station, a request associated with a synchronization signal block (SSB); and receiving the SSB from the base station, wherein a first period of the discovery signal can be longer than a second period of the SSB.

Description

Method and device for terminal request-based synchronization in a wireless communication system

[0001] The present disclosure relates to a communication method of a wireless communication system, and more specifically, to a terminal request-based synchronization method and apparatus of 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 frequency bands below 6 GHz ('Sub 6 GHz'), such as 3.5 gigahertz (3.5 GHz), but also in ultra-high frequency bands known as millimeter wave (mmWave), such as 28 GHz and 39 GHz ('Above 6 GHz'). In addition, for 6G mobile communication technology, which is referred to as a system beyond 5G, measures are being considered to achieve even faster transmission speeds and even lower ultra-low latency compared to 5G mobile communication technology.

[0003] In the early stages of 5G mobile communication technology, aiming to satisfy service support and performance requirements for enhanced Mobile BroadBand (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), technologies such as beamforming and Massive MIMO to mitigate path loss and increase transmission distance in ultra-high frequency bands, support for various numerologies (such as operating multiple subcarrier spacings) and dynamic operation of slot formats for the efficient utilization of ultra-high frequency resources, initial access techniques to support multi-beam transmission and broadband, definition and operation of Band-Width Parts (BWP), Low Density Parity Check (LDPC) codes for high-volume data transmission, new channel coding methods such as Polar Codes for reliable transmission of control information, and L2 pre-processing (L2 Standardization has been carried out for pre-processing, network slicing which provides a dedicated network specialized for specific services, and other methods.

[0004] In addition, discussions are underway to improve and enhance the performance of the initial 5G mobile communication technology in consideration of the services that the 5G mobile communication technology was intended to support. Standardization has been carried out for technologies such as V2X (Vehicle-to-Everything), which helps autonomous vehicles make driving decisions and enhance user convenience based on their own location and status information transmitted by the vehicle; NR-U (New Radio Unlicensed), which aims for system operation in unlicensed bands to comply with various regulatory requirements; NR terminal low power consumption technology (UE Power Saving); Non-Terrestrial Network (NTN), which is direct terminal-satellite communication for securing coverage in areas where communication with the terrestrial network is impossible; and positioning.

[0005] In addition, standardization was also carried out for technologies such as the Industrial Internet of Things (IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) which provides nodes to expand network service areas by integrating wireless backhaul links and access links, Mobility Enhancement including Conditional Handover and Dual Active Protocol Stack (DAPS) Handover, and 2-step RACH for NR which simplifies random access procedures.

[0006] In addition, standardization is underway for 5G baseline architectures (e.g., Service based Architecture, Service based Interface) for the integration of Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, as well as for Mobile Edge Computing (MEC), which provides services based on the location of the terminal.

[0007] With the commercialization of such 5G mobile communication systems, connected devices, which are increasing explosively, will be connected to communication networks. Accordingly, it is expected that there will be a need to enhance the functionality and performance of 5G mobile communication systems and to integrate the operation of connected devices. To this end, new research is planned to be conducted on 5G performance improvement and complexity reduction, support for AI services, support for metaverse services, and drone communication using eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0008] In addition, the advancement of these 5G mobile communication systems can serve as a foundation for the development of new waveforms for ensuring coverage of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas, metamaterial-based lenses and antennas, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), and Reconfigurable Intelligent Surface (RIS) technology, as well as Full Duplex technology for improving frequency efficiency and system networks of 6G mobile communication technology, AI-based communication technology that realizes system optimization by utilizing satellites and AI from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology that realizes services of complexity exceeding the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources.

[0009] According to one embodiment of the present disclosure, an apparatus and method capable of effectively providing services in a mobile communication system are provided.

[0010] According to one embodiment of the present disclosure, a method performed by user equipment (UE) comprises receiving a discovery signal for a cell associated with the base station from a base station, transmitting a request associated with a synchronization signal block (SSB) to the base station based on the discovery signal, and receiving the SSB from the base station, wherein the first period of the discovery signal may be longer than the second period of the SSB.

[0011] According to one embodiment of the present disclosure, an apparatus and a method capable of effectively providing services in a wireless communication system may be provided.

[0012] The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure belongs from the description below.

[0013] FIG. 1 is a diagram showing the basic structure of the time-frequency resource domain of a 5G system according to one embodiment of the present disclosure.

[0014] FIG. 2 is a diagram illustrating a random access procedure according to one embodiment of the present disclosure.

[0015] FIG. 3 is a diagram illustrating a procedure in which a terminal reports terminal capability (UE capability) information to a base station according to one embodiment of the present disclosure.

[0016] FIG. 4 is a drawing showing an example of a bandwidth portion setting according to an embodiment of the present disclosure.

[0017] FIG. 5 is a diagram showing the interrelationship between frequency bands and coverage according to one embodiment of the present disclosure.

[0018] FIG. 6 is a diagram showing an example of a base station energy saving method according to one embodiment of the present disclosure.

[0019] FIG. 7 is a drawing showing an example of a base station energy saving method according to one embodiment of the present disclosure.

[0020] FIG. 8 is a drawing showing an example of a base station energy saving method according to one embodiment of the present disclosure.

[0021] FIG. 9 is a drawing showing an example of a base station energy saving method according to one embodiment of the present disclosure.

[0022] FIG. 10 is a diagram illustrating an initial connection procedure of a terminal utilizing a discovery signal according to one embodiment of the present disclosure.

[0023] FIG. 11 is a diagram illustrating an initial connection procedure of a terminal utilizing a discovery signal according to one embodiment of the present disclosure.

[0024] FIG. 12 is a diagram illustrating an initial connection procedure of a terminal utilizing a discovery signal according to an embodiment of the present disclosure.

[0025] FIG. 13 is a diagram showing the initial connection procedure of a terminal according to one embodiment of the present disclosure.

[0026] FIG. 14 is a diagram showing the time relationship between a discovery signal and an on-demand SSB (synchronization signal block) transmission according to one embodiment of the present disclosure.

[0027] FIG. 15 is a diagram showing the time relationship between a discovery signal and an on-demand SSB transmission according to one embodiment of the present disclosure.

[0028] FIG. 16 is a diagram showing the frequency relationship between a discovery signal and an on-demand SSB transmission according to one embodiment of the present disclosure.

[0029] FIG. 17 is a diagram showing the frequency relationship between a discovery signal and an on-demand SSB transmission according to one embodiment of the present disclosure.

[0030] FIG. 18 is a diagram showing the frequency relationship between a discovery signal and an on-demand SSB transmission according to one embodiment of the present disclosure.

[0031] FIG. 19 is a diagram showing the time relationship between a discovery signal and a terminal request signal according to one embodiment of the present disclosure.

[0032] FIG. 20 is a diagram showing the time relationship between a discovery signal and a terminal request signal according to one embodiment of the present disclosure.

[0033] FIG. 21 is a drawing showing an example of an initial connection procedure of a terminal according to one embodiment of the present disclosure.

[0034] FIG. 22 is a diagram showing an example of a base station procedure for supporting a terminal initial connection procedure according to one embodiment of the present disclosure.

[0035] FIG. 23 is a drawing showing a terminal transceiver device according to one embodiment of the present disclosure.

[0036] FIG. 24 is a block diagram illustrating the structure of a terminal according to one embodiment of the present disclosure.

[0037] FIG. 25 is a block diagram illustrating the structure of a base station according to one embodiment of the present disclosure.

[0038] Hereinafter, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. Furthermore, in describing the present disclosure, if it is determined that a detailed description of related known functions or configurations might unnecessarily obscure the essence of the present disclosure, such detailed description will be omitted. Additionally, the terms described below are defined considering their functions in the present disclosure, and these may vary depending on the intentions or practices of the user or operator. Therefore, their definitions should be based on the content throughout this specification.

[0039] The advantages and features of the present disclosure and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below but may be implemented in various different forms. The embodiments provided are merely to make the present disclosure 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. Throughout the specification, the same reference numerals refer to the same components.

[0040] At this time, it will be understood that each block of the process flow diagrams and combinations of the flow diagrams can be executed by computer program instructions. Since these computer program instructions can be loaded into the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, the instructions executed through the processor of the computer or other programmable data processing equipment may create means for performing the functions described in the flow diagram block(s). Since these computer program instructions may also be stored in computer-available or computer-readable memory that can be directed toward the computer or other programmable data processing equipment to implement the function in a specific way, the instructions stored in computer-available or computer-readable memory may also be able to produce a manufactured item containing instruction means for performing the function described in the flow diagram block(s). Since computer program instructions can be loaded onto a computer or other programmable data processing equipment, instructions that execute a computer or other programmable data processing equipment by performing a series of operation steps on the computer or other programmable data processing equipment to create a process executed by the computer may also provide steps for executing the functions described in the flowchart block(s).

[0041] Additionally, each block may represent a module, and / or segment, or part of code containing one or more executable instructions for executing a specified logical function(s). Also, it should be noted that in some alternative execution examples, the functions mentioned in the blocks may occur out of order. For example, two blocks shown in succession may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order according to their corresponding functions.

[0042] In this embodiment, the term "part" used may refer to software or hardware components such as FPGAs (Field Programmable Gate Arrays) or ASICs (Application Specific Integrated Circuits), and the "part" performs certain roles. However, the meaning of "part" is not limited to software or hardware. The "part" may be configured to reside in an addressable storage medium or configured to run one or more processors. Thus, as an example, the "part" includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and / or 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." In addition, the components and 'parts' may be implemented to utilize one or more CPUs within the device or secure multimedia card. Also, in the embodiments, 'parts' may include one or more processors.

[0043] In the present disclosure, each of the phrases such as “A or B,” “at least one of A and B,” “at least one of A or B,” “A, B or C,” “at least one of A, B and C,” and “at least one of A, B, or C” may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof. Terms such as “first,” “second,” or “first” or “second” may be used simply to distinguish a corresponding component from another corresponding component and do not limit the corresponding components in other aspects (e.g., importance or order).

[0044] In describing the present disclosure below, specific descriptions of related known functions or configurations will be omitted if it is determined that such detailed descriptions would unnecessarily obscure the essence of the present disclosure. Embodiments of the present disclosure are described below with reference to the attached drawings.

[0045] Terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, terms referring to various identification information, etc., are examples provided for the convenience of explanation. Accordingly, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meanings may be used.

[0046] In the following description, the terms "physical channel" and "physical signal" may be used interchangeably with "data" or "control signal." For example, PDSCH (physical downlink shared channel) is a term referring to a physical channel through which data is transmitted, but PDSCH may also be used to refer to data. That is, in this disclosure, the expression "transmits a physical channel" may be interpreted as equivalent to the expression "transmits data or a signal through a physical channel."

[0047] In the present disclosure, upper layer signaling may refer to a signal transmission method transmitted from a base station to a terminal using a physical layer downlink data channel, or from a terminal to a base station using a physical layer uplink data channel. Upper layer signaling may be understood as a Master Information Block (MIB), System Information Block (SIB), Radio Resource Control (RRC) signaling, or Media Access Control (MAC) control element (CE).

[0048] For convenience of explanation below, terms and names defined in the 3GPP NR (New Radio: 5th generation mobile communication standard) specifications may be used in this disclosure. However, this disclosure is not limited to the above terms and names and may be applied equally to systems conforming to other standards. For example, regarding 6G systems, which are still in the early stages of standardization discussion, terms and names defined in 5G systems may be generalized and used to describe the operation of 6G systems unless otherwise specifically noted.

[0049] Hereinafter, the base station is an entity that performs resource allocation for terminals and may be at least one of a gNodeB (next generation node B), gNB, eNodeB (EUTRAN (evolved universal terrestrial radio access network) node B), eNB, NodeB, BS (Base Station), radio access unit, base station controller, or a node on a network. The terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, IoT device, sensor, or multimedia system capable of performing communication functions. Of course, it is not limited to the examples described.

[0050] While existing mobile communication systems focused on conventional voice / data communication, 5G systems aim to satisfy various services and requirements, such as enhanced mobile broadband (eMBB) services to improve existing voice / data communication, ultra-reliable and low latency communication (URLLC) services, and / or massive machine type communication (MTC) services to support mass communication of the machine.

[0051] While the transmission bandwidth per carrier of existing mobile communication systems, such as LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)) and LTE-A (LTE-Advanced or E-UTRA Evolution), is limited to a maximum of 20 MHz, 5G systems can utilize a significantly wider ultra-wide bandwidth to aim for ultra-high-speed data services reaching several Gbps as their primary goal. Accordingly, 5G systems can consider ultra-high frequency bands ranging from several GHz to a maximum of 100 GHz as operating frequencies, where securing ultra-wide bandwidth frequencies is relatively easy. Additionally, it may be possible to secure wide bandwidth frequencies for 5G systems through frequency reallocation or allocation from frequency bands ranging from several hundred MHz to several GHz used by existing mobile communication systems.

[0052] Radio waves in the ultra-high frequency band have wavelengths of several millimeters and are also called millimeter waves (mmWave). However, in the ultra-high frequency band, path loss of radio waves increases in proportion to the frequency band, so the coverage of mobile communication systems can be reduced.

[0053] According to one embodiment, to overcome the disadvantage of reduced coverage in the ultra-high frequency band, beamforming technology may be applied to increase the reach of radio waves by using multiple antennas to concentrate the radiated energy of radio waves toward a predetermined target point. That is, a signal to which beamforming technology is applied has a relatively narrow beam width, and since the radiated energy is concentrated within the narrowed beam width, the reach of the radio waves can be increased. Beamforming technology can be applied to both the transmitting end and the receiving end. In addition to the effect of increasing coverage, beamforming technology may have the effect of reducing interference in areas other than the beamforming direction. For beamforming technology to operate properly, accurate measurement and feedback methods of the transmitting and / or receiving beams may be required. Beamforming technology can be applied to a control channel or data channel that corresponds one-to-one between a predetermined terminal and a base station. In addition, beamforming technology may be applied to common signals transmitted by a base station to multiple terminals within the system, such as synchronization signals, physical broadcast channels (PBCH), control channels for transmitting system information, and data channels, to increase coverage. When applying beamforming technology to common signals, beam sweeping technology, which changes the beam direction to transmit the signal, is additionally applied to ensure that the common signal reaches terminals located at any position within the cell.

[0054] Another requirement for 5G systems is ultra-low latency services, where the transmission delay between the transmitter and receiver is approximately 1ms. As a measure to reduce transmission delay, it is necessary to design a frame structure based on a short TTI (transmission time interval) that is shorter than that of LTE and LTE-A. The TTI is the basic time unit for performing scheduling, and the TTI of existing LTE and LTE-A systems can be 1ms, which corresponds to the length of one subframe. For example, in 5G systems, short TTIs such as 0.5ms, 0.25ms, and / or 0.125ms, which are shorter than those of existing LTE and LTE-A systems, may be possible to satisfy the requirements for ultra-low latency services.

[0055] The disclosed embodiments aim to provide an apparatus and method capable of effectively providing mobile communication services. Specifically, they provide a procedure for energy saving of a base station and a terminal.

[0056] The technical problems to be solved in the disclosed embodiments are not limited to those mentioned above, and other unmentioned technical problems may be considered by those skilled in the art from the various embodiments of the present disclosure described below.

[0057] Embodiments of the present disclosure provide a transmitting / receiving device and method for a terminal and a base station that improve frequency usage efficiency in a mobile communication system. Specifically, according to at least one embodiment of the present disclosure, the base station and the terminal can effectively perform an initial connection procedure for energy saving of the base station and the terminal.

[0058] The effects obtainable from the disclosed embodiments are not limited to those mentioned above, and other unmentioned effects can be clearly derived and understood by a person skilled in the art based on the following detailed description.

[0059] FIG. 1 is a diagram showing the basic structure of a time-frequency resource domain of a 5G (generation) system according to one embodiment of the present disclosure. FIG. 1 is a diagram showing the basic structure of a time-frequency resource domain, which is a wireless resource domain where data or control channels of a 5G system are transmitted.

[0060] Referring to FIG. 1, the horizontal axis in FIG. 1 may represent the time domain, and the vertical axis may represent the frequency domain. The minimum transmission unit in the time domain of a 5G system is an OFDM (orthogonal frequency division multiplexing) symbol, A number of symbols (102) are combined to form a slot (106), and A number of slots can be combined to form a single subframe (105). The length of a single subframe (105) may be 1.0 ms, and 10 subframes may be combined to form a single frame (114), and the length of the frame (114) may be 10 ms. 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 several subcarriers (104).

[0061] According to one embodiment, the basic unit of a resource in the time-frequency domain can be represented as a resource element (RE) (112) with an OFDM symbol index and a subcarrier index. A resource block (RB or Physical Resource Block, PRB) in the frequency domain It can be defined as a series of consecutive subcarriers (110). In a 5G system = 12, and the data rate can increase in proportion to the number of RBs scheduled to the terminal.

[0062] According to one embodiment, in a 5G system, a base station maps data in units of resource blocks (RBs) and can generally perform scheduling on RBs that constitute one slot for a given terminal. That is, in a 5G system, the basic time unit for which scheduling is performed is a slot, and the basic frequency unit for which scheduling is performed may be an RB.

[0063] According to one embodiment, the number of OFDM symbols It can be determined by the length of the cyclic prefix (CP) added to each symbol to prevent interference between symbols. For example, if a normal CP is applied = 14, if Extended CP is applied = 12. Extended CP is applied to systems with relatively longer transmission distances than standard CP, enabling the maintenance of orthogonality between symbols. In the case of standard CP, the ratio of CP length to symbol length is maintained at a constant value, allowing the overhead caused by CP to remain constant regardless of the subcarrier spacing. That is, if the subcarrier spacing is small, the symbol length increases, and consequently, the CP length can also increase. Conversely, if the subcarrier spacing is large, the symbol length decreases, and consequently, the CP length can be reduced. The symbol length and CP length can be inversely proportional to the subcarrier spacing.

[0064] In 5G systems, various frame structures can be supported by adjusting the subcarrier spacing to satisfy various services and requirements. For example, the characteristics according to the subcarrier spacing are as follows.

[0065] From the perspective of the operating frequency band, a larger subcarrier spacing can be advantageous for recovering phase noise in the high-frequency band.

[0066] - From the perspective of transmission time, a large subcarrier spacing shortens the symbol length in the time domain, and consequently shortens the slot length, which can be advantageous for supporting ultra-low latency services such as URLLC.

[0067] - From the perspective of cell size, a longer CP length allows for the support of larger cells, so a smaller subcarrier spacing allows for the support of relatively larger cells. In mobile communication, a cell can be a concept referring to an area covered by a single base station.

[0068] Subcarrier spacing and / or CP length are essential information for OFDM transmission and reception, and smooth transmission and reception are possible only when the base station and the terminal recognize the subcarrier spacing and CP length as common values. [Table 1] shows examples of the relationships between subcarrier spacing configuration (μ), subcarrier spacing (Δf), and CP length supported by 5G systems.

[0069]

[0070] [Table 2] shows the number of symbols per slot for each subcarrier spacing setting (μ) in the case of general type CP ( ), number of slots per frame( ), and number of slots per subframe( Represents an example of ).

[0071]

[0072] [Table 3] shows the number of symbols per slot for each subcarrier spacing setting (μ) in the case of extended CP ( ), number of slots per frame( ), number of slots per subframe( Represents an example of ).

[0073]

[0074] A 5G system can satisfy various user requirements through coexistence or dual-mode operation with existing LTE (long term development) or / and LTE-A (hereinafter LTE / LTE-A (advanced)) systems. For example, existing LTE / LTE-A systems can provide stable system operation to terminals, while 5G systems can perform the role of providing enhanced services to terminals. Therefore, the frame structure of a 5G system needs to include at least the frame structure of LTE / LTE-A or a set of essential parameters (subcarrier spacing = 15 kHz).

[0075] For example, when comparing a frame structure with a subcarrier spacing setting μ=0 (hereinafter frame structure A) and a frame structure with a subcarrier spacing setting μ=1 (hereinafter frame structure B), it can be shown that compared to frame structure A, frame structure B has a subcarrier spacing and RB size that are twice as large, and a slot length and symbol length that are twice as small. In the case of frame structure B, two slots can form one subframe, and 20 subframes can form one frame.

[0076] By generalizing the frame structure of a 5G system, high scalability can be provided by ensuring that the essential parameter sets, such as the subcarrier spacing, CP length, and / or slot length, have an integer multiple relationship with each other for each frame structure. Additionally, a subframe of a fixed length of 1ms can be defined to represent a reference time unit independent of the frame structure.

[0077] The frame structure of a 5G system can be applied to various scenarios. From the perspective of cell size, since a longer CP length enables support for larger cells, Frame Structure A can support relatively larger cells compared to Frame Structure B. From the perspective of operating frequency band, since a larger subcarrier spacing is advantageous for recovering phase noise in the high-frequency band, Frame Structure B can support relatively higher operating frequencies compared to Frame Structure A. From the perspective of service, since a shorter slot length—the basic time unit of scheduling—is advantageous for supporting ultra-low latency services such as URLLC, Frame Structure B may be relatively more suitable for URLLC services compared to Frame Structure A.

[0078] In a manner similar to the coexistence of 5G and LTE / LTE-A, it may be necessary to design a system for the coexistence of 6G, which will arrive with the evolution of future communication systems, and existing systems such as 5G or LTE / LTE-A.

[0079] In the following description of the present disclosure, an uplink (UL) refers to a wireless link through which a terminal transmits data or control signals to a base station, and a downlink (DL) may refer to a wireless link through which a base station transmits data or control signals to a terminal.

[0080] According to one embodiment, in the initial access stage where the terminal first connects to the system, the terminal can synchronize downlink time and frequency from a synchronization signal transmitted by a base station through a cell search and obtain a cell ID. Then, 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. The MIB may include at least some of the following information.

[0081]

[0082] For example, essential system information may include at least one of the following: information regarding the location of a synchronization signal received by the terminal in the time domain and / or frequency domain; control information for the terminal to receive at least one of the system information (or system information block, SIB) transmitted by the base station (which may be information for scheduling a data channel for receiving system information); information regarding whether the cell is accessible; and information regarding the subcarrier spacing (SCS) of the cell. Essential system information may be referenced as system information.

[0083] Additionally, the terminal can receive system information transmitted by the base station to obtain cell-common transmission and reception control information. Cell-common transmission and reception control information may include random access control information, paging control information, and at least one of various physical channels and signals (at least one of channels and signals, such as an uplink control channel, an uplink data channel, a downlink control channel and a downlink data channel, a physical signal for obtaining uplink channel status information, a physical signal for obtaining downlink channel status information, and a physical signal for demodulating a physical channel). For example, the control information may be configuration information for each channel or signal. For example, the system information may be referenced as SIB1, or RMSI (remaining minimum system information).

[0084] According to one embodiment, the synchronization signal is a signal serving as a reference for cell search, and a 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 control channel, the subcarrier spacing may be applied differently depending on the service type to support various services as described above. In a 5G system, a combination consisting of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH) may be referred to as an SS / PBCH block or an SSB. For example, an SSB may consist of N1 PSS symbols, N2 SSS symbols, and N3 PBCH symbols.

[0085] In addition to the initial connection procedure, the terminal may also receive the SSB to determine whether the radio link quality of the current cell is maintained above a certain level. Furthermore, during the procedure for the terminal to perform a handover from the current cell to an adjacent cell, the terminal may receive the SSB of the adjacent cell to determine the radio link quality of the adjacent cell and to obtain time / frequency synchronization with the adjacent cell.

[0086] According to one embodiment, after the terminal obtains MIB and system information from the base station through an initial access procedure, the terminal may perform a random access procedure to switch the link with the base station to a connected state (connected state or RRC_CONNECTED state). Upon completion of the random access procedure, the terminal switches to a connected state, and one-to-one communication between the base station and the terminal may become possible. The random access procedure is described in detail below with reference to FIG. 2.

[0087] FIG. 2 is a diagram illustrating a random access procedure according to one embodiment of the present disclosure.

[0088] Referring to FIG. 2, as a first step (210) of the random access procedure, the terminal can transmit a random access preamble to the base station. The random access preamble, which is the initial transmission message of the terminal in the random access procedure, may be referred to as message 1. The base station can measure the transmission delay value between the terminal and the base station from the random access preamble and can synchronize the uplink. At this time, the terminal can arbitrarily select which random access preamble to use from a set of random access preambles given in advance by system information. Also, the initial transmission power of the random access preamble can be determined according to the path loss between the base station and the terminal measured by the terminal. Additionally, the terminal can transmit the random access preamble by determining the transmission beam direction of the random access preamble from the synchronization signal received from the base station.

[0089] According to one embodiment, in the second step (220), the base station may transmit a message to the terminal containing an uplink transmission timing control command based on a transmission delay value measured from the random access preamble received in the first step (210). The terminal may receive control information for scheduling the message over a downlink control channel and receive the message over a downlink data channel based on the control information. The message transmitted in the second step may be referred to as message 2, a response to the random access preamble, or a random access response. Additionally, the base station may transmit the message by including, as scheduling information, uplink resources to be used by the terminal to transmit a response message (message 3) to message 2 and power control commands to be applied to the response message. The scheduling information may include control information regarding the terminal's uplink transmission beam. Additionally, the message may further include a temporary identifier of the terminal to be used during the random access procedure. The information included in the message is merely an example, and one or more of the information described above may be included in message 2.

[0090] If the terminal does not receive message 2, which is scheduling information for message 3, from the base station within a predetermined time in the second step (220), the terminal may perform the first step (210) again. If the first step (210) is performed again, the terminal may increase the probability of receiving the random access preamble at the base station by increasing the transmission power of the random access preamble by a predetermined step (power ramping).

[0091] According to one embodiment, in the third step (230), the terminal can transmit uplink data (message 3) including its terminal ID to the base station via the uplink data channel (physical uplink shared channel, PUSCH) based on the uplink resources allocated in the second step (220). The transmission timing of the uplink data channel for transmitting Message 3 may follow the uplink transmission timing control command received from the base station in the second step (220). The transmission power of the uplink data channel for transmitting Message 3 may be determined by considering the power control command received from the base station in the second step (220) and the power ramping value of the random access preamble. The uplink data channel for transmitting Message 3 may be referenced as the first uplink data signal transmitted by the terminal to the base station after the terminal transmits the random access preamble. For example, the message 3 may include an upper layer message for the terminal to connect to the network.

[0092] According to one embodiment, if the base station determines in step 4 (240) that the terminal has performed random access without collision with other terminals, it may transmit data (message 4) containing the ID of the terminal that transmitted uplink data in step 3 (230) to the terminal. If the terminal receives the signal transmitted by the base station in step 4 (240) from the base station, it may determine that the random access was successful. The terminal may transmit HARQ-ACK information indicating successful reception of message 4 to the base station through the Physical Uplink Control Channel (PUCCH).

[0093] If the data transmitted by the terminal in the third step (230) collides with the data of another terminal and the base station fails to receive the data signal from the terminal, the base station may not transmit any further data to the terminal. Accordingly, if the terminal fails to receive the data transmitted from the base station in the fourth step (240) within a certain period of time, it is determined that the random access procedure has failed, and the process may be restarted from the first step (210).

[0094] The above-described four-step random access procedure is merely an example, and the information between the terminal and the base station described above may also be transmitted through messages other than the four-step message described above. For example, the terminal may transmit one or more messages containing at least one of the information of message 1 and message 3 to the base station simultaneously or sequentially, and the base station may transmit one or more messages containing at least one of the information of message 2 and message 4 to the terminal simultaneously or sequentially.

[0095] Upon successful completion of the random access procedure, the terminal transitions to a connected state, enabling one-to-one communication between the base station and the terminal. The base station can receive UE capability information from the terminal in the connected state. The base station can adjust scheduling by referring to the UE capability information of the terminal. Through the UE capability information, the terminal can inform the base station whether it supports certain functions and / or the maximum allowable value of the functions supported by the terminal. Therefore, the UE capability information reported by each terminal to the base station may be different for each terminal.

[0096] For example, the terminal may report UE capability information to the base station as UE capability information, including at least a portion of the following control information.

[0097] - Control information related to frequency bands supported by the terminal

[0098] - Control information related to channel bandwidth supported by the terminal

[0099] - Control information regarding the maximum modulation scheme supported by the terminal

[0100] - Control information regarding the maximum number of beams supported by the terminal

[0101] - Control information regarding the maximum number of layers supported by the terminal

[0102] - Control information related to CSI reporting supported by the terminal

[0103] - Control information on whether the terminal supports frequency hopping

[0104] - Bandwidth-related control information when Carrier Aggregation (CA) is supported

[0105] - Control information on whether cross-carrier scheduling is supported when carrier bundling is supported

[0106] FIG. 3 is a diagram illustrating a procedure in which a terminal reports terminal capability (UE capability) information to a base station according to one embodiment of the present disclosure.

[0107] Referring to FIG. 3, in step 310, the base station (302) can send a UE capability information request message to the terminal (301). In response to the base station's UE capability information request, the terminal can send UE capability information to the base station in step 320.

[0108] Next, the Bandwidth Part (BWP) setting in the 5G communication system is explained in detail with reference to the drawing.

[0109] Figure 4 is a diagram illustrating an example of a bandwidth portion setting in a 5G communication system.

[0110] FIG. 4 shows an example in which the terminal bandwidth (UE bandwidth) (400) is configured into two bandwidth portions, namely bandwidth portion #1 (BWP#1) (401) and bandwidth portion #2 (BWP#2) (402). The base station may configure one or more bandwidth portions for the terminal and may configure the information in below for each bandwidth portion.

[0111]

[0112] Of course, the above examples are not limited, and various parameters related to bandwidth portions may be configured for the terminal in addition to configuration information. This information may be transmitted from the base station to the terminal via higher-layer signaling, for example, RRC (Radio Resource Control) signaling. Among the one or more configured bandwidth portions, at least one bandwidth portion may be activated. Whether a configured bandwidth portion is activated may be transmitted semi-statically from the base station to the terminal via RRC signaling or dynamically via DCI (downlink control information).

[0113] According to one embodiment, prior to the RRC connection, the terminal may receive an Initial Bandwidth Part (Initial BWP) for initial connection from the base station via a Master Information Block (MIB). For example, during the initial connection phase, the terminal may receive configuration information regarding a Control Resource Set (CORESET) and a Search Space via the MIB, through which a Physical Downlink Control Channel (PDCCH) can be transmitted to receive System Information Blocks required for initial connection. The Control Resource Set and Search Space configured via the MIB may each be considered as Identity (ID) 0 (CORESET 0, Search Space 0). The base station may notify the terminal via the MIB of configuration information, such as frequency allocation information, time allocation information, and / or subcarrier interval settings, for Control Resource Set #0. Additionally, the base station may notify the terminal via the MIB of configuration information regarding the monitoring period and monitoring occasion for Control Resource Set #0 (e.g., configuration information for Search Space #0). The terminal may consider (or identify) the frequency region set as control region #0 obtained from the MIB as an initial bandwidth portion for initial access. At this time, the identifier (ID) of the initial bandwidth portion may be considered (or identified) as 0.

[0114] The settings for the bandwidth supported by 5G can be used for various purposes.

[0115] According to one embodiment, if the bandwidth supported by the terminal is smaller than the system bandwidth, this can be supported through the bandwidth portion setting. For example, by setting the frequency position of the bandwidth portion (setting information 2) to the terminal, the terminal can transmit and / or receive data at a specific frequency position within the system bandwidth.

[0116] According to one embodiment, a base station may set multiple bandwidth portions for a terminal for the purpose of supporting different subcarrier spacing settings. For example, to support data transmission and reception using both a 15 kHz subcarrier spacing and a 30 kHz subcarrier spacing for a terminal, two bandwidth portions may be set to subcarrier spacings of 15 kHz and 30 kHz, respectively. Different bandwidth portions may be subjected to frequency division multiplexing (FDM), and when data is to be transmitted and / or received at a specific subcarrier spacing, the bandwidth portion set as the subcarrier spacing may be activated.

[0117] According to one embodiment, for the purpose of reducing the power consumption of the terminal, a base station may set a bandwidth portion having a bandwidth of different sizes for the terminal. For example, if the terminal supports a very large bandwidth, e.g., 100 MHz, and always transmits and receives data using that bandwidth, very large power consumption may occur. For example, in a situation where there is no traffic, monitoring an unnecessary downlink control channel using a large bandwidth of 100 MHz may be very inefficient in terms of power consumption. For the purpose of reducing the power consumption of the terminal, the base station may set a bandwidth portion of a relatively small bandwidth (e.g., a bandwidth portion of 20 MHz) for the terminal. In a situation where there is no traffic, the terminal may perform monitoring operations in the 20 MHz bandwidth portion, and when data is generated, it may transmit and / or receive data using the 100 MHz bandwidth portion according to the instructions of the base station.

[0118] Regarding the method of configuring the bandwidth portion, terminals prior to RRC connection (Connected) can receive configuration information for the Initial Bandwidth Part (Initial BWP) via the MIB during the initial connection phase. For example, a terminal can receive a configuration for a control area (e.g., CORESET) for a downlink control channel through which a DCI scheduling a System Information Block (SIB) can be transmitted from the MIB of the Physical Broadcast Channel (PBCH). The bandwidth of the control area configured based on the MIB can be considered as the Initial Bandwidth Part, and through the configured Initial Bandwidth Part, the terminal can receive the Physical Downlink Shared Channel (PDSCH) through which the SIB is transmitted. In addition to receiving the SIB, the Initial Bandwidth Part may also be utilized for paging or random access.

[0119] Next, downlink control information (DCI) in a 5G system is described in detail.

[0120] In a 5G system, scheduling information for uplink data (or physical uplink shared channel, PUSCH) or scheduling information for downlink data (or physical downlink shared channel, PDSCH) can be transmitted from a base station to a terminal via downlink control information (DCI). The terminal can monitor the fallback DCI format and the non-fallback DCI format for PUSCH or PDSCH. The fallback DCI format may consist of fixed fields predefined between the base station and the terminal, and the non-fallback DCI format may include configurable fields.

[0121] According to one embodiment, the DCI can be transmitted through a physical downlink control channel (PDCCH) after undergoing channel coding and modulation processes. A cyclic redundancy check (CRC) is attached to the DCI message payload, and the CRC can be scrambled with the terminal's identity identifier (e.g., radio network temporary identifier, RNTI). Different RNTIs may be used depending on the purpose of the DCI message, e.g., terminal-specific (UE-specific) data transmission, power control commands, or random access responses. That is, the RNTI may not be explicitly transmitted but may be included in the CRC calculation process. Upon receiving a DCI message transmitted through the PDCCH, the terminal checks the CRC using the assigned RNTI, and if the result of the CRC check is correct, the terminal knows that the message has been transmitted to the terminal.

[0122] For example, a DCI scheduling a PDSCH for system information can be scrambled into SI (system information)-RNTI. For example, a DCI scheduling a PDSCH for a RAR (random access response) message can be scrambled into RA-RNTI. For example, a DCI scheduling a PDSCH for a paging message can be scrambled into P-RNTI. A DCI notifying an SFI (slot format indicator) can be scrambled into SFI-RNTI. A DCI notifying a TPC (transmit power control) can be scrambled into TPC (transmit power control)-RNTI. For example, a DCI scheduling a terminal-specific PDSCH or PUSCH can be scrambled into C-RNTI (cell RNTI).

[0123] According to one embodiment, a base station may operate by applying a predetermined DCI format to a terminal to be scheduled, depending on whether the DCI is for scheduling information for downlink data (downlink assignment), scheduling information for uplink data (uplink grant), and / or for DCI for purposes other than data scheduling, such as power control.

[0124] A base station can transmit downlink data to a terminal via the Physical Downlink Shared Channel (PDSCH), which is a physical channel for downlink data transmission. Scheduling information, such as specific mapping locations in the time and frequency domains of the PDSCH, modulation schemes, HARQ-related control information, and / or power control information, can be provided by the base station to the terminal through the DCI related to downlink data scheduling information among the DCIs transmitted via the PDSCH.

[0125] According to one embodiment, a terminal can transmit uplink data to a base station via a physical uplink shared channel (PUSCH), which is a physical channel for transmitting uplink data. Scheduling information, such as specific mapping locations in the time and frequency domains of the PUSCH, modulation schemes, HARQ-related control information, and / or power control information, can be provided by the base station to the terminal through a DCI related to uplink data scheduling information among the DCIs transmitted via the PDCCH.

[0126] According to one embodiment, the time-frequency resource to which the PDCCH is mapped may be referred to as a control resource set (CORESET). In the frequency domain, the CORESET may be set to all or part of the frequency resources of the bandwidth supported by the terminal. In the time domain, it may be set to one or more OFDM symbols, which may be defined as the CORESET duration. A base station may set one or more CORESETs to the terminal via upper-layer signaling (e.g., System Information, Master Information Block (MIB), and / or Radio Resource Control (RRC) signaling). Setting a CORESET to the terminal may mean providing information such as the CORESET identity, the frequency location of the CORESET, and the symbol length of the CORESET. The information provided by the base station to the terminal to set the CORESET may include at least some of the information included in [Table 6].

[0127]

[0128]

[0129] According to one embodiment, CORESET (control resource set) is in the frequency domain It can be composed of RBs, and in the time domain It can be composed of symbols. A PDCCH can be composed of one or more Control Channel Elements (CCEs). One CCE can be composed of six Resource Element Groups (REGs), and a REG can be defined as one RB during one Orthogonal Frequency Division Multiplexing (OFDM) symbol. Within a single CoreSet, REGs can be indexed in Time-First order, starting with REG index 0, from the first OFDM symbol of the CoreSet, the lowest RB.

[0130] According to one embodiment, interleaved and non-interleaved methods may be supported as transmission methods for PDCCH. The base station may set whether to perform interleaved or non-interleaved transmission 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. Based on whether to perform interleaved or non-interleaved transmission set by the base station, the terminal may determine the CCE-to-REG mapping method in the CORESET in the manner shown in below.

[0131]

[0132] According to one embodiment, the base station can notify the terminal of configuration information, such as which symbol the PDCCH is mapped to within the slot and the transmission period, through signaling.

[0133] According to one embodiment, the search space of a PDCCH may be described as follows. The number of CCEs required to transmit a PDCCH may be 1, 2, 4, 8, or 16 depending on the Aggregation Level (AL), and different numbers of CCEs may be used for link adaptation of the downlink control channel. For example, when AL=L, one downlink control channel may be transmitted through L CCEs. The terminal 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 may be defined. The search space is a set of downlink control channel candidates consisting of CCEs that the terminal must attempt to decode at a given aggregation level, and since there are various aggregation levels that form a bundle of 1, 2, 4, 8, or 16 CCEs, the terminal may have multiple search spaces. A Search Space Set can be defined as a set of search spaces at all established aggregation levels.

[0134] Search spaces can be classified into Common Search Spaces (CSS) and UE-specific Search Spaces (USS). A certain group of terminals or all terminals may monitor the Common Search Space of the PDCCH to receive cell-common control information, such as dynamic scheduling or paging messages for System Information Blocks (SIBs). For example, a terminal may receive scheduling allocation information for the PDSCH for receiving system information by monitoring the Common Search Space of the PDCCH. In the case of the Common Search Space, since a certain group of terminals or all terminals must receive the PDCCH, it may be defined as a pre-agreed set of CCEs. Scheduling allocation information for the UE-specific PDSCH or PUSCH may be received by the terminal by examining the UE-specific Search Space of the PDCCH. The UE-specific Search Space may be defined specifically as a function of the terminal's ID (Identity) and various system parameters.

[0135] According to one embodiment, a base station may set configuration information for the search space of a PDCCH to a terminal via upper layer signaling (e.g., SIB, MIB, and / or RRC signaling). For example, the base station may set to the terminal the number of PDCCH candidates at each aggregation level L, the monitoring period for the search space, the occasion for monitoring in slot-symbol units for the search space, the search space type (common search space or terminal-specific search space), the combination of DCI format and RNTI to be monitored in the search space, and / or the CORESET index to be monitored in the search space. For example, parameters for the search space for a PDCCH may include at least one of the information shown in below.

[0136]

[0137]

[0138]

[0139] According to one embodiment, based on configuration information, a base station may set one or more sets of search spaces for a terminal. According to one embodiment, a base station may set search space set 1 and search space set 2 for a 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.

[0140] According to one embodiment, one or more sets of search spaces may exist in a common search space or a terminal-specific search space based on configuration information. For example, search space set #1 and search space set #2 may be configured as a common search space, and search space set #3 and search space set #4 may be configured as a terminal-specific search space.

[0141] According to one embodiment, in a common search space, a terminal can monitor at least one of the following combinations of DCI format and RNTI. However, the scope of the present invention is not limited to the following examples.

[0142] - 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

[0143] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0144] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0145] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0146] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0147] According to one embodiment, in a terminal-specific search space, the terminal may monitor at least one of the following combinations of DCI format and RNTI. However, the scope of the present invention is not limited to the following examples.

[0148] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0149] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0150] RNTIs may follow at least one of the following definitions and uses.

[0151] C-RNTI (Cell RNTI): Used for terminal-specific PDSCH or PUSCH scheduling

[0152] TC-RNTI (Temporary Cell RNTI): Used for terminal-specific PDSCH scheduling

[0153] CS-RNTI (Configured Scheduling RNTI): Used for semi-static terminal-specific PDSCH scheduling.

[0154] RA-RNTI (Random Access RNTI): Used for PDSCH scheduling during the random access phase.

[0155] P-RNTI (Paging RNTI): Used for PDSCH scheduling where paging is transmitted.

[0156] SI-RNTI (System Information RNTI): Used for PDSCH scheduling where system information is transmitted.

[0157] INT-RNTI (Interruption RNTI): Used to indicate whether PDSCH has been punctured.

[0158] TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to instruct power control commands to the PUSCH

[0159] TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to instruct power control commands to the PUCCH

[0160] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to instruct power regulation commands to the SRS

[0161] The DCI formats described above may follow the definitions in below.

[0162]

[0163] The search space of aggregation level L in CORESET p and search space set s can be expressed as [Equation 1] below.

[0164]

[0165] The value may be 0 for the common search space.

[0166] 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 the ID set by the base station for the terminal) and the time index.

[0167] The following describes in detail how a terminal in a 5G communication system measures channel conditions and reports them to a base station.

[0168] Channel state information (CSI) may include at least one of the following information.

[0169] - Channel Quality Indicator (CQI): CQI index indication information consisting of a modulation scheme and coding rate that satisfy the predefined minimum receive error rate of PDSCH.

[0170] - Precoding Matrix Indicator (PMI): Precoding matrix indicator information selected by the terminal

[0171] - CRI (CSI-RS resource indicator): CSI-RS information measured by the terminal

[0172] - RI (Rank Indicator): Rank indicator information selected by the terminal

[0173] - LI (Layer indicator): Indicator information for the best layer among the precoding matrices reported by the terminal

[0174] - SSBRI (SS / PBCH block resource indicator): SSB information measured by the terminal

[0175] - L1-RSRP (Reference Signal Received Power): L1 RSRP information measured by the terminal

[0176] The base station can control at least one of the time or frequency resources for the aforementioned CSI measurement and reporting of the terminal.

[0177] According to one embodiment, 'aperiodic', 'semi-persistent', and / or 'periodic' methods may be supported for CSI measurement and reporting operations, and the base station may set which method to use for the terminal through signaling. For example, a semi-persistent CSI reporting method may support 'semi-persistent on PUCH' and / or 'semi-persistent on PUSCH'. In the case of a periodic or semi-persistent CSI reporting method, the terminal may receive a PUCCH or PUSCH resource to transmit the CSI from the base station through upper-layer signaling. The period and slot offset of the PUCCH or PUSCH resource to transmit the CSI may be provided by the subcarrier interval setting of the uplink (UL) bandwidth part configured for CSI reporting transmission. In the case of a non-periodic CSI reporting method, the terminal can receive a PUSCH resource to transmit the CSI from the base station via L1 (layer 1) signaling (the aforementioned DCI format 0_1) scheduling.

[0178] According to one embodiment, non-periodic CSI reporting of the terminal may use PUSCH, and periodic CSI reporting may use PUCCH. Additionally, semi-permanent CSI reporting may be performed using PUSCH when triggered or activated by DCI, and using PUCCH after being activated by a MAC control element (MAC CE).

[0179] According to one embodiment, a non-periodic CSI report can be triggered by the “CSI request” field of the aforementioned DCI format 0_1, which corresponds to the scheduling DCI for PUSCH.

[0180] As a means to support ultra-high-speed data services, 5G systems can support signal transmission and reception with ultra-wide bandwidths of tens to hundreds of MHz or several GHz. Signal transmission and reception with ultra-wide bandwidths can be supported through a single component carrier (CC) or through Carrier Aggregation (CA) technology that combines multiple component carriers. For example, Carrier Aggregation technology can be referenced as a technology that enables ultra-high-speed data services by combining individual component carriers with relatively small bandwidths to increase the total frequency bandwidth, in cases where a mobile operator has not secured a frequency bandwidth sufficient for providing ultra-high-speed data services through a single component carrier.

[0181] According to one embodiment, the frequency bands utilized by a 5G system can be extensive, ranging from hundreds of MHz to tens of GHz. FIG. 5 illustrates the interrelationships between frequency bands, coverage, and bandwidth. FIG. 5 shows frequency bands of a low band (501), a mid band (502), a high band (503), and an ultra-high band (504). Generally, the lower the frequency band, the greater the coverage due to relatively less path loss, while the higher the frequency band, the smaller the coverage due to relatively higher path loss. In low frequency bands, frequencies available for mobile communication are fragmented, resulting in small bandwidth, whereas in high frequency bands, it is relatively easy to secure wide bandwidth frequencies, making them suitable for ultra-high-speed data services. As mobile communication systems evolve, efforts are being made to discover and utilize new frequency bands. For example, the next-generation mobile communication system, 6G (6 thIn generation mobile communication systems, the 7 to 15 GHz band, called the upper midband, is being considered as one of the candidate frequencies.

[0182] Mobile operators can secure multiple frequency bands to provide mobile communication services to users. For example, a mobile operator can combine existing frequency bands for LTE systems with newly secured frequency bands for 5G systems to operate a combined LTE and 5G system (e.g., EN(EUTRAN-NR)-DC(dual connectivity)). As another example, a mobile operator can secure frequency bands for 5G systems across multiple bands and then combine the frequencies from those bands to provide mobile communication services through 5G CA. Similarly, a 6G mobile communication system can provide mobile communication services through 6G CA by combining 6G frequencies with existing 4G or 5G frequencies, or by combining 6G frequencies with each other.

[0183] As mentioned above, since characteristics such as coverage and / or bandwidth vary depending on the frequency band, there is a growing trend toward mobile communication services that combine multiple frequency bands rather than those relying on a single frequency band.

[0184] According to one embodiment, as another method for supporting ultra-high-speed data services, there may be a method of increasing the data rate through a spatial multiplexing method using multiple transmitting and receiving antennas. The number of power amplifiers (PAs) required may also increase in proportion to the number of transmitting antennas equipped in the base station or terminal. The maximum output of the base station and terminal depends on the characteristics of the power amplifiers, and generally, the maximum output of the base station may vary depending on the cell size covered by the base station. Typically, the maximum output can be expressed in dBm units. The maximum output of the terminal may typically be 23 dBm or 26 dBm.

[0185] According to one embodiment, as an example of a commercial 5G base station, the base station may be equipped with 64 transmitting antennas and corresponding 64 power amplifiers in the 3.5 GHz frequency band and operate at a bandwidth of 100 MHz. Consequently, the energy consumption of the base station increases in proportion to the output of the power amplifiers and the operating time of the power amplifiers. Compared to LTE base stations, 5G base stations have a relatively higher operating frequency band, so they may be characterized by having a wide bandwidth and many transmitting antennas. While this characteristic has the effect of increasing the data rate, it may result in costs associated with increased energy consumption of the base station. Therefore, the more base stations constituting a mobile communication network there are, the greater the energy consumption of the entire mobile communication network may become in proportion to that number.

[0186] According to one embodiment, the energy consumption of a base station may be largely determined by the operation of a power amplifier. Since the power amplifier is involved in the base station transmission operation, the base station's DL (downlink) transmission operation is highly related to the base station's energy consumption. Relatively speaking, the base station's UL (uplink) reception operation does not account for a large proportion of the base station's energy consumption. The physical channel and physical signal transmitted by the base station via the downlink may be as follows.

[0187] - PDSCH (Physical Downlink Shared Channel): A downlink data channel containing data to be transmitted to one or more terminals.

[0188] - PDCCH (Physical Downlink Control Channel): A downlink control channel containing scheduling information for PDSCH and PUSCH (Physical Uplink shared Channel). Alternatively, PDCCH alone can transmit control information such as slot formats and power control commands without the PDSCH or PUSCH to be scheduled. The scheduling information includes resource information mapped to the PDSCH or PUSCH, HARQ (hybrid automatic repeat request) related information, power control information, etc.

[0189] - PBCH (Physical Broadcast Channel): A downlink broadcast channel that provides the MIB (Master Information Block), which is essential system information required for the transmission and reception of the terminal's data and control channels.

[0190] - PSS (Primary Synchronization Signal): A signal that serves as the reference for DL ​​(downlink) time / frequency synchronization and provides some cell ID information.

[0191] - SSS (Secondary Synchronization Signal): A signal that serves as the reference for DL ​​time and / or frequency (hereinafter time / frequency) synchronization and provides the cell ID (identity) and some other information.

[0192] - DM-RS (Demodulation Reference Signal): A reference signal for terminal channel estimation for each of PDSCH, PDCCH, and PBCH.

[0193] - CSI-RS (Channel-state Information Reference Signal): A downlink signal that serves as a reference for measuring the downlink channel state of a terminal.

[0194] - PT-RS (Phase-tracking Reference Signal): Downlink signal for phase tracking

[0195] According to one embodiment, from the perspective of base station energy saving, if the base station stops downlink transmission operation, the resulting cessation of power amplifier operation can lead to a higher energy saving effect. Additional energy savings may be possible by reducing the operation of other base station devices, such as baseband devices, in addition to the power amplifier. Similarly, even if uplink reception operation accounts for a relatively small proportion of the base station's total energy consumption, additional energy savings can be obtained if the uplink reception operation can be stopped.

[0196] Various methods for saving base station energy are described below with reference to FIGS. 6, FIGS. 7, FIGS. 8, and / or FIGS. 9.

[0197] - Base Station Energy Saving Method 1: The downlink transmission operation of a base station may depend on the amount of downlink traffic. For example, if there is no data to be transmitted to a terminal via the downlink, the base station does not need to transmit a PDSCH and a PDCCH (physical downlink control channel) (or DCI) for scheduling the PDSCH. Alternatively, if data transmission can be temporarily suspended for reasons such as the data not being sensitive to transmission delay, the base station may not transmit the PDSCH or / and PDCCH. This is illustrated through FIG. 6. FIG. 6 is a diagram illustrating an example of a base station energy saving method according to an embodiment of the present disclosure. Referring to FIG. 6, the amount of traffic that the base station intends to transmit may be maintained at a level higher than a threshold value during the T1 period (610) and the T3 period (630), and the amount of traffic that the base station intends to transmit may be maintained at a level lower than a threshold value during the T2 period (620). In this case, the base station may stop or minimize the operation of the base station power amplifier, the operation of the base station RF (radio frequency) device, and / or the operation of the base band device by not transmitting the PDSCH for data transmission and the PDCCH for scheduling the PDSCH during the T2 period (620). In this case, the energy of the base station may be saved. Additionally, if the traffic intended to be processed during the T2 period (620) is not sensitive to transmission delay, the base station may defer transmission during the T2 period (620) and perform delayed transmission during the T3 period (630). On the other hand, the base station may transmit the PDSCH (602) for data transmission and the PDCCH (601) for scheduling the PDSCH without restriction during the T1 period (610) and the T3 period (630), thereby ensuring that there is no hindrance to the provision of the base station's communication service. For example, the base station state in the T1 section (610) and the T3 section (630) may be referred to as the base station normal state.For example, the base station state in the T2 period (620) may be referred to as the base station power saving state (Energy Saving state, ES state). For example, a threshold value for the amount of traffic may be communicated to the base station by an entity governing base station operations (e.g., AMF (access and mobility management function), SMF (session management function), PCF (policy control function)) through signaling, or the base station may determine it on its own.

[0198] - Base Station Energy Saving Method 2: Physical channels and physical signals, such as PSS, SSS, PBCH, and / or CSI (channel state information)-RS (reference signal), may be transmitted repeatedly at a predetermined period regardless of data transmission to the terminal. Therefore, even if the terminal does not receive data, it can continuously update downlink time / frequency synchronization, downlink channel status, and / or radio link quality. That is, PSS, SSS, PBCH, and / or CSI-RS are essentially transmitted over the downlink regardless of downlink data traffic, and this may cause base station energy consumption. Therefore, the energy consumption of the base station can be reduced by controlling the transmission of signals unrelated to (or less relevant to) data traffic to occur less frequently. This is illustrated through FIG. 7. FIG. 7 is a diagram illustrating an example of a base station energy saving method according to an embodiment of the present disclosure. Referring to FIG. 7, in the T1 (710) and T3 (730) sections, which are the base station normal state, the base station can transmit periodic signals (703), such as PSS, SSS, PBCH, and / or CSI-RS, with a predefined transmission period 1 (701). On the other hand, in the T2 (720) section, which is the base station power saving state, the base station can intermittently perform or minimize operations of the base station power amplifier, base station RF device, and / or baseband device by transmitting periodic signals (704) with a transmission period 2 (702), which is relatively longer than the transmission period 1 (701). In this case, the energy consumption of the base station can be reduced.

[0199] - Base Station Energy Saving Method 3: A base station can reduce its energy consumption by switching off at least some of its antennas or power amplifiers. This is illustrated, for example, through FIG. 8. FIG. 8 is a diagram illustrating an example of a base station energy saving method according to an embodiment of the present disclosure. Referring to FIG. 8, in the base station normal state periods T1 (810) and T3 (830), the base station can transmit downlink signals based on a predefined transmission power 1 or M1 transmission antennas (801). On the other hand, in the base station power saving state period T2 (820), the base station can stop or minimize the operation of base station power amplifiers, base station RF devices, and / or baseband devices, etc., by transmitting downlink signals based on a transmission power 2 that is smaller than the transmission power 1 or M2 transmission antennas (802) that are relatively smaller than the M1 transmission antennas (801). In this case, the energy consumption of the base station can be reduced.

[0200] - Base Station Energy Saving Method 4: In an environment where carrier bundling is applied, when the amount of traffic to be transmitted by the base station is kept below a threshold value, the base station may transmit the traffic through a predetermined configuration carrier and switch off the remaining configuration carriers, thereby stopping or minimizing the operation of the power amplifier, RF device, and / or baseband device of the switched-off configuration carriers. In this case, the energy consumption of the base station may be reduced. For example, this is illustrated with reference to FIG. 9. FIG. 9 is a diagram illustrating an example of a base station energy saving method according to an embodiment of the present disclosure. Referring to FIG. 9, configuration carrier 1 (901) and configuration carrier 2 (902) are operated as a carrier bundling. In the example of FIG. 9, the amount of traffic that the base station intends to transmit during the T1 period (910) and the T3 period (930) may be kept high above a threshold value, and the amount of traffic that the base station intends to transmit during the T2 period (920) may be kept low below a threshold value. In this case, to save energy, the base station may operate the base station power saving state during the T2 period (920), switch off configuration carrier 2 (902), and have configuration carrier 1 (901) handle the traffic processing during the T2 period (920). On the other hand, during the base station normal state during the T1 period (910) and the T3 period (930), both configuration carrier 1 (901) and configuration carrier 2 (902) are activated to quickly process a relatively large amount of traffic.

[0201] According to one embodiment, base station energy saving methods 1, 2, 3, and / or 4 may be applied and operated individually, or may be operated in combination with each other.

[0202] According to one embodiment, the base station state is represented in two stages: a base station general state and a base station power saving state, but this is merely an example, and the base station power saving state can be distinguished in more detail. For example, the base station power saving state can be distinguished in conjunction with the base station's energy saving method. In this case, base station power saving state 1 represents a base station power saving state according to base station energy saving method 1, base station power saving state 2 represents a base station power saving state according to the base station energy saving method 2, base station power saving state 3 represents a base station power saving state according to base station energy saving method 3, and base station power saving state 4 represents a base station power saving state according to the base station energy saving method 4.

[0203] The operation of the system proposed in this disclosure is explained below through specific embodiments.

[0204] In the present disclosure, even if the base station is in a base station power saving state, the base station may transmit a discovery signal to facilitate identification of the base station by the terminal. Upon detecting the discovery signal, the terminal may request the base station to transmit a synchronization signal, and the base station may transmit a synchronization signal to the terminal in response to the terminal's request. Through such a series of procedures, the terminal can establish a connection to the base station that is in a base station power saving state.

[0205] The following initial access procedure may include at least one of the discovery signal between the terminal and the base station, the transmission / reception of the terminal request signal, the synchronization signal, and system information, or the random access procedure between the terminal and the base station. Subsequently, the terminal may request an attach to the network, and after the attach procedure is completed, it may transmit and receive packets (or data (e.g., PDU (protocol data unit))) through the network.

[0206] The following description of specific embodiments may be as follows. The present disclosure may include a plurality of embodiments, each of which may be implemented independently as a distinction made for convenience to explain the implementation according to the present disclosure; however, as long as they are not mutually exclusive, all or part of the plurality of embodiments may be selectively combined and implemented. Such combinations include various variations and modifications of the present disclosure and may be made in various ways depending on technical needs or application environments. Even if the plurality of embodiments use different approaches to achieve the purpose of the invention, they may be used simultaneously or complementarily as long as the embodiments of the present disclosure are not technically mutually exclusive. Such combinations may be varied depending on technical requirements or specific application cases, and the present invention may encompass various embodiments including such variations and combinations. Although the name of a 5G system is used to describe the embodiments of the present disclosure, this is merely an example and can be understood as a message that includes information or performs the same role as described below.

[0207] <1st Embodiment>

[0208] In the first embodiment, operations related to the terminal and the base station according to the initial connection procedure of the terminal utilizing the discovery signal described above are explained. The terminal initial connection procedure of the first embodiment may be described by dividing it into phase 1 and phase 2 before and after the transmission time of the base station's normal synchronization signal and / or SSB. During Phase 1, the base station or the terminal may transmit at least some of the following signals.

[0209] - A discovery signal transmitted by a base station to a terminal to notify the presence of a base station or cell: Similar to a synchronization signal, the discovery signal can be a sequence-based signal and can be composed of a combination of one or more sequences. By detecting the discovery signal, the terminal can recognize (or identify) that a cell transmitting the discovery signal is present in the vicinity of the terminal. The discovery signal can be transmitted periodically. By transmitting the discovery signal with a relatively long transmission periodicity, an energy saving effect (or network energy saving (NES)) of the base station can be expected during the periods when the discovery signal is not transmitted.

[0210] - A terminal request signal in which a terminal requests the base station to transmit a synchronization signal or an SSB: If the terminal succeeds in detecting a discovery signal, the terminal may request the transmission of a synchronization signal or an SSB to the cell associated with the discovery signal. By applying a pre-agreed configuration and format to the terminal request signal, the processing complexity for the base station to receive the terminal request signal may be reduced. Alternatively, the discovery signal may indicate the configuration and format of the terminal request signal within a predetermined limited range.

[0211] - On-demand SSB transmitted by the base station in response to a terminal request: From the on-demand SSB, the terminal can synchronize time and / or frequency. The on-demand SSB is an SSB transmitted in response to a terminal request and may be transmitted once, transmitted a predetermined number of times (N), or transmitted for a predetermined time interval (W). The number of times (N) and / or the time interval (W) may use pre-agreed values ​​or may be set by the base station for the terminal. For example, the base station may set the number of times (N) and / or the time interval (W) for the terminal via a radio resource control (RRC) message, a medium access control (MAC) control element (CE), and / or DCI. As a modified example of the on-demand SSB, the base station may transmit an on-demand synchronization signal. The on-demand synchronization signal may be a synchronization signal transmitted in response to a terminal request.

[0212] The base station or terminal may transmit at least some of the following signals during Phase 2.

[0213] - Synchronization signal or SSB transmitted by the base station to the terminal: It is a reference signal that enables the terminal to synchronize time and / or frequency, and can provide the terminal with a cell identifier. The synchronization signal is transmitted periodically and can be transmitted with a relatively short transmission periodicity compared to the discovery signal.

[0214] - PDCCH for scheduling SIBs transmitted by the base station to the terminal (hereinafter referred to as SIB PDCCH for convenience)

[0215] - A PDSCH that carries the SIB transmitted by the base station to the terminal (hereinafter referred to as SIB PDSCH for convenience).

[0216] - Random access preamble transmitted by the terminal to the base station

[0217] The initial connection procedure of a terminal utilizing a discovery signal according to the first embodiment can be described by the following various methods.

[0218] - Initial connection procedure 1 of a terminal utilizing a discovery signal: With reference to FIG. 10 below, the initial connection procedure 1 of a terminal utilizing a discovery signal is described. First, a base station (1030) can transmit a discovery signal (1001). For example, the discovery signal is a cell common signal and may have the characteristic of being transmitted with a relatively long transmission cycle. Even if the base station (1030) is in a power saving state, the base station (1030) can notify terminals within the cell coverage (e.g., terminal (1040)) of the presence of the base station by transmitting the discovery signal. A terminal (1040) that has successfully detected the discovery signal can transmit a terminal request signal (1002) to the base station (1030) to request the transmission of an on-demand SSB. A base station (1030) that has received a terminal request signal may transmit an on-demand SSB (1003) to the terminal (1040) based on the request of the terminal (1040). In the example of FIG. 10, the step of the base station (1030) and the terminal (1040) transmitting and receiving a discovery signal, a terminal request signal, and / or an on-demand SSB may be referred to as phase 1 (1010). Subsequently, in phase 2 (1020), the base station (1030) may enable the terminal (1040) to synchronize time and / or frequency and obtain a cell identifier through the transmission of an SSB (1004). Then, the terminal (1040) may obtain control information (e.g., time and frequency resource information of the SIB PDCCH) related to the SIB (system information block) PDCCH to be received in the next step from the MIB obtained through the SSB (1004). Subsequently, the terminal (1040) can obtain a SIB by receiving the SIB PDCCH (1005) and SIB PDSCH (1006). The SIB may include cell-common transmission and / or reception control information. The terminal (1040) can transmit a random access preamble (1007) based on the control information of the SIB.

[0219] - Initial connection procedure 2 of a terminal utilizing a discovery signal: With reference to FIG. 11 below, the initial connection procedure 2 of a terminal utilizing a discovery signal is described. The initial connection procedure 2 of a terminal utilizing a discovery signal can be referenced in a manner where the on-demand SSB transmission (1003) step is omitted from the initial connection procedure 1 of a terminal utilizing a discovery signal. Accordingly, a base station (1130) that receives a terminal request signal (1102) can enter phase 2 (1120) and perform the operation of receiving an SSB (1103) from the base station (1130). The remaining procedures are identical to the initial connection procedure 1 of the terminal utilizing the discovery signal, so a separate explanation is omitted. (Subsequently, in phase 2 (1120), the base station (1130) can enable the terminal (1140) to synchronize time and / or frequency and obtain a cell identifier through the transmission of an SSB (1103). Then, the terminal (1140) can obtain control information (e.g., time and frequency resource information of the SIB PDCCH) related to the SIB (system information block) PDCCH to be received in the next step from the MIB obtained through the SSB (1103). Subsequently, the terminal (1140) can obtain the SIB by receiving the SIB PDCCH (1104) and the SIB PDSCH (1105). The SIB may include cell-common transmission and / or reception-related control information. The terminal (1040) can transmit a random access preamble (1106) based on the control information of the SIB. there is.)

[0220] - Initial connection procedure 3 of a terminal (1240) utilizing a discovery signal: With reference to FIG. 12 below, the initial connection procedure 3 of a terminal (1240) utilizing a discovery signal (1201) is described. The initial connection procedure 3 of a terminal (1240) utilizing a discovery signal (1201) can be described as a method in which the step of the base station (1230) transmitting a response signal (1203) corresponding to the terminal request signal (1202) is added to the initial connection procedure 1 of a terminal (1240) utilizing a discovery signal (1201). For example, the response signal (1203) may indicate that the base station (1230) has successfully received the terminal request signal (1202) and may additionally provide control information related to the on-demand SSB (1204). The terminal (1240) that has obtained the response signal (1203) can perform the receiving operation of the on-demand SSB (1204). The remaining procedures may be substantially the same as the initial connection procedure 1 of the terminal (1240) using the discovery signal (1201). (Subsequently, in phase 2 (1220), the base station (1230) may enable the terminal (1240) to synchronize time and / or frequency and obtain a cell identifier through the transmission of an SSB (1205). Then, the terminal (1240) may obtain control information (e.g., time and frequency resource information of the SIB PDCCH) related to the system information block (SIB) PDCCH to be received in the next step) from the MIB obtained through the SSB (1205). Subsequently, the terminal (1240) may obtain the SIB by receiving the SIB PDCCH (1206) and the SIB PDSCH (1207). The SIB may contain cell-common transmission and / or reception control information. The terminal (1240) may transmit a random access preamble (1208) based on the control information of the SIB.)

[0221] According to one embodiment, the discovery signal may be transmitted with a relatively long transmission period, and the SSB may be transmitted with a relatively short transmission period. The mutual time relationship between the discovery signal and the SSB transmission is described below with reference to FIG. 13. In the example of FIG. 13, the transmission period of the discovery signal may be referenced as P1 (1330), and the transmission period of the SSB may be referenced as P2 (1340) (e.g., P1 > P2). For convenience of explanation, the candidate time interval in which the discovery signal may be transmitted may be referenced as the discovery signal transmission occasion, and the candidate time interval in which the SSB may be transmitted may be referenced as the SSB transmission occasion. In the example of FIG. 13, it is assumed that the base station is in a base station power saving state (1370) during the phase 1 (1350) period, and subsequently, the base station is in a base station normal state (1370) during the phase 2 (1360) period. In the base station power saving state, the base station may omit SSB transmission and transmit a discovery signal with a relatively long transmission period. In this case, the base station can achieve a power saving effect. Therefore, during phase 1 (1350), which is the base station power saving state (1370), the terminal may attempt to detect (or monitor) the discovery signal at the discovery signal transmission occasion and may not attempt to detect the SSB at the SSB transmission occasion. Subsequently, during phase 2 (1360), which is the base station normal state (1370), the terminal may attempt to detect (or monitor) the SSB at the SSB transmission occasion.

[0222] According to one embodiment, if the terminal succeeds in detecting a discovery signal (1302) transmitted within a discovery signal transmission occasion at time T1 (1390), the terminal may transmit a terminal request signal (1303) to the base station requesting transmission of an on-demand SSB. The base station may then transmit an on-demand SSB (1304) to the terminal based on the terminal request signal. The terminal may obtain a certain level of time and / or frequency synchronization from the received on-demand SSB (1304). Based on the terminal request signal, the base station may switch the base station state from a base station power saving state to a base station normal state and perform normal (or non-NES applied) transmission and reception operations. During phase 2 (1360) in which the base station has switched to a base station normal state, the terminal may attempt to detect (or monitor) the SSB at every SSB transmission occasion. In the base station normal state, the terminal can synchronize time and / or frequency from at least one SSB (1306, 1307, 1308, 1309) transmitted by the base station and obtain a cell identifier. Based on the MIB obtained through the SSB, the terminal can obtain control information related to the SIB PDCCH to be received in the next step (e.g., time and / or frequency resource information of the SIB PDCCH). Subsequently, the terminal can obtain a SIB by receiving the SIB PDCCH and SIB PDSCH. The SIB may include cell-common transmit / receive control information. Based on the control information of the SIB, the terminal can transmit a random access preamble.

[0223] The power saving state and general state of the present disclosure may be replaced with various terms. For example, the power saving state and general state may be replaced with a first state and a second state, respectively. The power saving state and general state may be replaced with a state that is in NES mode and a state that is not in NES mode, respectively.

[0224] The discovery signal and the SSB may be configured to have substantially the same channel structure, or independent channel structures, or have a subset channel structure relationship with each other.

[0225] - Same channel structure: The discovery signal and the SSB can be configured to have substantially the same channel structure and can be distinguished as signals with different transmission periods.

[0226] - Independent channel structure: The discovery signal and the SSB can be configured to have independent channel structures. In this case, they can be configured with channel structures optimized for the characteristics of each signal.

[0227] - Subset channel structure: A discovery signal of a simplified structure can be configured from a predetermined SSB channel structure. For example, the SSB may be composed of a PSS, SSB, and / or PBCH of a predetermined narrow bandwidth, and the discovery signal may be composed of the PSS and / or SSB constituting the SSB. Additionally, the on-demand SSB may also be configured from the SSB in a simplified structure.

[0228] The example in FIG. 13 describes a case where beam sweeping operation of the SSB in a multi-beam environment is not considered, but this is merely an example. For example, the example in FIG. 13 can be generalized and applied even when beam sweeping is applied. For example, the SSB transmitted at each SSB transmission occasion can be replaced with L SSBs corresponding to L different beams. For example, the discovery signal transmitted at each discovery signal transmission occasion can be replaced with K discovery signals corresponding to K different beams.

[0229] Although the names of 5G systems have been used to describe embodiments of the present disclosure, the names such as discovery signal, on-demand SSB, SSB, PSS, SSS, PBCH, PDCCH, and / or PDSCH described above are merely examples and may be understood as messages that include information or perform the same role as described above.

[0230] <Second Embodiment>

[0231] The second embodiment describes the relationship between the discovery signal and the on-demand SSB and the operations related to the terminal and the base station accordingly during the initial connection procedure of a terminal utilizing the discovery signal described above.

[0232] As described above, a terminal that has successfully detected a discovery signal can transmit a terminal request signal to the base station requesting on-demand SSB transmission. In the second embodiment, the time and / or frequency resource relationship between the discovery signal and the on-demand SSB is defined so that the terminal can smoothly receive the on-demand SSB after detecting the discovery signal.

[0233] One method of the second embodiment is described below with reference to FIG. 14. In the example of FIG. 14, one frame (1430) may be composed of half frame #1 (1440) and half frame #2 (1450). A half frame may include 10 slots (1460).

[0234] FIG. 14 shows that a discovery signal (1410) is transmitted after a predetermined offset interval (1400) from the start point of the frame. For example, the offset interval (1400) may be set to a value agreed upon in advance between the terminal and the base station, or the base station may inform the terminal of control information included in the discovery signal through signaling (e.g., RRC message, MAC CE, and / or DCI). In the example of FIG. 14, when the discovery signal is transmitted in half-frame #1 (1440) within the frame, an on-demand SSB (1420) corresponding to the terminal request signal of the terminal may be transmitted in half-frame #2 (1450). Thus, a time interval (hereinafter referred to as 'time interval 1' for illustrative purposes) can be secured between the discovery signal and the on-demand SSB with a length equal to the sum of the switching gap 1 (1401), the terminal request signal transmission occasion (1402), and the switching gap 2 (1403). For example, the switching gap 1 (1401) may correspond to the minimum switching time required for the terminal to start processing the uplink signal, the terminal request signal, after completing the downlink signal, the discovery signal detection processing. Therefore, it may be impossible for the terminal to transmit the terminal request signal before all the time corresponding to the switching gap 1 (1401) has elapsed. For example, the terminal request signal transmission occasion (1402) may be referenced as a candidate time interval for the terminal to transmit the terminal request signal. When the terminal is ready to send the terminal request signal, the terminal can transmit the terminal request signal to the base station within the terminal request signal transmission occasion interval.For example, switching gap 2 (1403) may correspond to the minimum switching time required for the terminal to complete the transmission operation of the terminal request signal, which is an uplink signal, and then start the on-demand SSB detection processing, which is a downlink signal. Therefore, the terminal may need to complete the transmission of the terminal request signal before the switching gap 2 (1403) begins. In the example of FIG. 14, the on-demand SSB is described as having the SSB beam sweeping to represent L = 8 beams (1404). According to the example of FIG. 14, the terminal that has successfully detected the discovery signal may transmit the terminal request signal to the base station within the terminal request signal transmission occasion interval, and may attempt to detect the on-demand SSB from 'time interval 1' after the discovery signal detection. Thus, uncertainty regarding the timing of the transmission and reception operations of the discovery signal, terminal request signal, and / or on-demand SSB is eliminated, and the complexity of the terminal operation may be resolved.

[0235] With reference to FIG. 15, another method of the second embodiment is described below. FIG. 15 may show that a discovery signal (1510) is transmitted after a predetermined offset interval (1500) from the start point of half-frame #2 (1550) of the n-th frame (1530). The offset interval (1500) may be determined by a value agreed upon in advance between the terminal and the base station, or the base station may inform the terminal of control information included in the discovery signal through signaling (e.g., RRC message, MAC CE, and / or DCI). In the example of FIG. 15, when the discovery signal is transmitted in half-frame #2 (1550) of the n-th frame (1530), an on-demand SSB (1520) corresponding to the terminal request signal of the terminal may be transmitted in half-frame #1 (1560) of the n+1-th frame (1540). Through this, a time interval (hereinafter referred to as 'time interval 2' for illustrative purposes) can be secured between the discovery signal and the on-demand SSB with a length equal to the sum of the switching gap 1 (1501), the terminal request signal transmission occasion (1502), and the switching gap 2 (1503). For example, the switching gap 1 (1501) may correspond to the minimum switching time required for the terminal to start processing the uplink signal, the terminal request signal, after completing the downlink signal, the discovery signal detection processing. Therefore, it may be impossible for the terminal to transmit the terminal request signal before the entire time corresponding to the switching gap 1 (1501) has elapsed. For example, the terminal request signal transmission occasion (1502) may be referenced as a candidate time interval for the terminal to transmit the terminal request signal. When the terminal is ready to send the terminal request signal, the terminal can transmit the terminal request signal to the base station within the terminal request signal transmission occasion interval.For example, switching gap 2 (1503) may correspond to the minimum switching time required for the terminal to complete the transmission operation of the terminal request signal, which is an uplink signal, and then start the on-demand SSB detection processing, which is a downlink signal. Therefore, the terminal may need to complete the transmission of the terminal request signal before the switching gap 2 (1503) begins. In the example of FIG. 15, the on-demand SSB is described as having the SSB beam sweeping to represent L = 8 beams (1504). According to the example of FIG. 15, the terminal that has successfully detected the discovery signal may transmit the terminal request signal to the base station within the terminal request signal transmission occasion interval. The terminal may attempt to detect the on-demand SSB after 'time interval 2' following the detection of the discovery signal. Thus, uncertainty regarding the timing of the transmission and reception operations of the discovery signal, the terminal request signal, and / or the on-demand SSB may be eliminated, and the complexity of the terminal operation may be resolved.

[0236] The examples in FIGS. 14 and 15 illustrate a possible time relationship between a discovery signal and an on-demand SSB, and various variations are possible. For instance, a discovery signal may be transmitted after a predetermined offset interval of 1 from the start point of the n-th frame, and an on-demand SSB may be transmitted after a predetermined offset interval of 2 from the start point of the n + k-th frame. In this case, at least some of the values ​​of offset 1, offset 2, and / or k may be determined as values ​​agreed upon in advance between the terminal and the base station, or the base station may notify the terminal via signaling as control information included in the discovery signal.

[0237] In the examples of FIGS. 14 and 15, the initial connection procedure is described with one discovery signal and L on-demand SSBs corresponding to the discovery signal, but the relationship between the discovery signal and the on-demand SSBs can be described in various ways as follows.

[0238] - Method 1: Define an initial connection procedure with one discovery signal and L on-demand SSBs, and the one discovery signal may correspond to L on-demand SSBs (1:L correspondence) (corresponding to the examples in FIGS. 14 and 15). For example, L on-demand SSBs may represent L beams.

[0239] - Method 2: Define an initial connection procedure with L discovery signals and L on-demand SSBs, where each discovery signal corresponds to each on-demand SSB (1:1 correspondence). For example, L discovery signals and L on-demand SSBs can represent L beams. For example, the k-th discovery signal among the L can correspond to the k-th on-demand SSB among the L. Therefore, a terminal that successfully detects the k-th discovery signal can transmit a terminal request signal and then attempt to detect the k-th on-demand SSB.

[0240] - Method 3: Define the initial connection procedure with M discovery signals and L on-demand SSBs, and there may be an (M:L correspondence) relationship where one discovery signal corresponds to L / M on-demand SSBs. For example, M discovery signals can represent M beams. For example, L on-demand SSBs can represent L beams. For example, when M = 4 and L = 8, the discovery signals and on-demand SSBs can correspond as follows.

[0241] The first discovery signal can correspond to the first on-demand SSB and the second on-demand SSB. Therefore, a terminal that has successfully detected the first discovery signal can transmit a terminal request signal and then attempt to detect the first on-demand SSB and the second on-demand SSB.

[0242] The second discovery signal can correspond to the third on-demand SSB and the fourth on-demand SSB. Therefore, the terminal that successfully detects the second discovery signal can transmit a terminal request signal and then attempt to detect the third on-demand SSB and the fourth on-demand SSB.

[0243] The third discovery signal can correspond to the fifth on-demand SSB and the sixth on-demand SSB. Therefore, a terminal that has successfully detected the third discovery signal can transmit a terminal request signal and then attempt to detect the fifth on-demand SSB and the sixth on-demand SSB.

[0244] The fourth discovery signal can correspond to the seventh on-demand SSB and the eighth on-demand SSB. Therefore, a terminal that has successfully detected the fourth discovery signal can transmit a terminal request signal and then attempt to detect the seventh on-demand SSB and the eighth on-demand SSB.

[0245] The frequency relationship between the discovery signal and the on-demand SSB can be described in the following way. Below, the transmission bandwidth of the discovery signal may be referred to as BW (bandwidth)1, and the transmission bandwidth of the on-demand SSB as BW2.

[0246] - Method 1: The transmission bandwidth of the discovery signal and the on-demand SSB may be the same (BW1 = BW2), and the mapping location in the frequency domain may also be substantially the same. Therefore, if the terminal succeeds in detecting the discovery signal, it may attempt to detect the on-demand SSB at the same frequency domain location and substantially the same transmission bandwidth as the discovery signal. FIG. 16 illustrates Method 1 regarding the frequency relationship between the discovery signal (1601) and the on-demand SSB (1602).

[0247] - Method 2: The transmission bandwidth of the discovery signal is smaller than the transmission bandwidth of the on-demand SSB (BW1 <BW2), 주파수 영역의 매핑 위치가 적어도 일부 중첩될 수 있다. 주파수 영역 매핑의 상대적인 위치는 사전에 단말과 기지국 사이에 약속된 값으로 정해지거나, 또는 기지국이 디스커버리 신호에 포함되는 제어 정보로 단말에게 시그널링으로 알려 줄 수 있다. 따라서, 단말이 디스커버리 신호를 검출하는데 성공하면 on-demand SSB의 주파수 영역 정보를 알 수 있고, 그에 따라 단말은 on-demand SSB의 검출을 시도할 수 있다. 도 17은 디스커버리 신호(1701)와 on-demand SSB(1702) 사이의 주파수 관계에 대한 방법 2를 예시한다.

[0248] - Method 3: The transmission bandwidth of the discovery signal is greater than the transmission bandwidth of the on-demand SSB (BW1 > BW2), and the mapping locations in the frequency domain may overlap at least partially. The relative locations of the frequency domain mapping may be determined by values ​​agreed upon in advance between the terminal and the base station, or the base station may inform the terminal via signaling using control information included in the discovery signal. Thus, if the terminal succeeds in detecting the discovery signal, it can know the frequency domain information of the on-demand SSB, and accordingly, the terminal can attempt to detect the on-demand SSB. FIG. 18 illustrates Method 3 regarding the frequency relationship between the discovery signal (1801) and the on-demand SSB (1802).

[0249] Although the second embodiment described the relationship between the discovery signal and the on-demand SSB and the operations related to the terminal and base station accordingly, this can be extended and applied to the relationship between the discovery signal and the SSB.

[0250] Although the names of 5G systems have been used to describe an embodiment of the present disclosure, the names such as discovery signal, on-demand SSB, SSB, frame, half frame, and / or slot described above are merely examples and can be understood as messages that include information as described above or perform the same role.

[0251] <Third Embodiment>

[0252] The third embodiment describes the relationship between the discovery signal and the terminal request signal and the operations related to the terminal and the base station accordingly during the initial connection procedure of a terminal utilizing the discovery signal described above.

[0253] As described above, a terminal that has successfully detected a discovery signal can transmit a terminal request signal to a base station requesting on-demand SSB transmission. In the third embodiment, as the time and frequency resource relationship between the discovery signal and the terminal request signal is defined, the terminal can smoothly transmit the terminal request signal after detecting the discovery signal.

[0254] The time relationship between the discovery signal and the terminal request signal can be defined in the following way.

[0255] - Method 1: The time relationship between the discovery signal and the terminal request signal can be defined as a value agreed upon in advance between the terminal and the base station. Referring to FIG. 19, a terminal (1920) that receives a discovery signal (1901) from the base station (1910) at time T1 (1903) can transmit a terminal request signal (1902) to the base station (1910) at time T2 (T2 = T1 + k, 1905), after k time has elapsed since time T1 (1903). For example, the value of k can be referenced as a value agreed upon between the terminal and the base station. And as described above, a switching gap (1904), which is the minimum time required for the terminal (1920) to switch from a downlink signal processing operation to an uplink signal processing operation, may be required.

[0256] - Method 2: The time relationship between the discovery signal and the terminal request signal can be defined as a range of values ​​agreed upon in advance between the terminal (2020) and the base station (2010). Referring to FIG. 20, the terminal (2020), which receives the discovery signal (2001) from the base station (2010) at time T1 (2003), can transmit the terminal request signal (2002) to the base station (2010) at time T2 (T1 + k1 ≤ T2 ≤ T1 + k2, 2005), which is within time k1 to k2 after time T1 (2003). For example, the values ​​of k1 and k2 can be determined as mutually agreed upon values ​​between the terminal (2020) and the base station (2010). And as described above, a switching gap (2004), which is the minimum time required for the terminal (2020) to switch from the processing operation of the downlink signal to the processing operation of the uplink signal, may be required.

[0257] - Method 3: A base station may notify the terminal of the transmission time of the terminal request signal via signaling through control information included in the discovery signal. For example, the base station may notify the terminal of the k1 value of Method 1 or the k1 and k2 values ​​of Method 2 via signaling. Thus, a terminal that has successfully detected the discovery signal can determine the transmission time of the terminal request signal. As with Methods 1 and 2, a switching gap may be required, which is the minimum time required for the terminal to switch from a downlink signal processing operation to an uplink signal processing operation.

[0258] The frequency relationship between the discovery signal and the terminal request signal may be as follows. Hereinafter, the transmission bandwidth of the discovery signal may be referred to as BW1, and the transmission bandwidth of the terminal request signal may be referred to as BW2.

[0259] - Method 1: The mapping locations in the frequency domain of the discovery signal and the terminal request signal may be substantially the same. Therefore, if the terminal succeeds in detecting the discovery signal, it may transmit the terminal request signal at a location in the frequency domain substantially the same as the discovery signal, based on the time relationship between the discovery signal and the terminal request signal.

[0260] - Method 2: The frequency domain mapping locations of the discovery signal and the terminal request signal may overlap at least partially. The relative locations of the frequency domain mapping may be determined by a value agreed upon in advance between the terminal and the base station, or the base station may inform the terminal via signaling using control information included in the discovery signal. Therefore, if the terminal succeeds in detecting the discovery signal, it can know the frequency domain information of the terminal request signal. In this case, the terminal may transmit the terminal request signal based on the time relationship between the discovery signal and the terminal request signal.

[0261] - Method 3: The frequency domain mapping locations of the discovery signal and the terminal request signal may not overlap. The relative locations of the frequency domain mapping may be determined by a value agreed upon in advance between the terminal and the base station, or the base station may inform the terminal of this through signaling using control information included in the discovery signal. Therefore, if the terminal succeeds in detecting the discovery signal, it can know the frequency domain information of the terminal request signal, and the terminal can transmit the terminal request signal based on the time relationship between the discovery signal and the terminal request signal.

[0262] Although the name of a 5G system has been used to describe an embodiment of the present disclosure, the name described above is merely an example and can be understood as a message that includes information as described above or performs the same role.

[0263] FIG. 21 may show an example of an initial connection procedure of a terminal according to one embodiment of the present disclosure.

[0264] Referring to FIG. 21, in step 2101, the terminal may attempt to detect a discovery signal transmitted by the base station (e.g., monitoring).

[0265] According to one embodiment, when a terminal successfully detects a discovery signal, the terminal can identify that a cell exists around the terminal, and in step 2102, the terminal can transmit a terminal request signal to request the base station to transmit an on-demand SSB. The mutual relationship between the discovery signal and the terminal request signal may follow the description above.

[0266] According to one embodiment, the terminal that transmitted the terminal request signal may attempt to receive the on-demand SSB in step 2103 (e.g., monitoring). The correlation between the discovery signal and the on-demand SSB may follow the description above.

[0267] According to one embodiment, a terminal that has received an on-demand SSB may attempt to receive the SSB in step 2104. The terminal may perform downlink time and / or frequency synchronization from the SSB received from the base station and obtain a cell identifier (e.g., cell ID). For example, the SSB may include at least one of a synchronization signal or a PBCH. For example, the terminal may obtain an MIB, which is essential system information, in step 2104. For example, the terminal may receive a PBCH using the cell ID obtained from the synchronization signal and obtain an MIB, which is essential system information, from the PBCH. For example, the MIB may include at least one of CORESET information or PDCCH configuration information, which is a time-frequency resource to which a PDCCH (e.g., DCI) is mapped.

[0268] According to one embodiment, in step 2105, the terminal can monitor the SIB PDCCH based on the acquired PDCCH configuration information. The terminal can receive the SIB PDCCH from the scheduling information of the SIB PDCCH and acquire system information (e.g., SIB). The SIB may include cell-common transmission / reception related control information. For example, the SIB may include random access related control information, paging related control information, and / or common control information for various physical channels.

[0269] According to one embodiment, in step 2106, the terminal may proceed with a random access procedure with a base station. For example, the terminal may transmit a random access preamble to the base station, and the base station may transmit a RAR to the terminal in response to the random access preamble.

[0270] The steps described above may be modified, omitted, changed in order, or undesired steps may be added to perform the present invention.

[0271] FIG. 22 is a diagram showing an example of a base station procedure for supporting a terminal initial connection procedure according to one embodiment of the present disclosure.

[0272] According to one embodiment, in step 2201, the base station may transmit a discovery signal to notify terminals within cell coverage of the presence of the base station.

[0273] According to one embodiment, in step 2202, the base station may attempt to receive a terminal request signal transmitted by the terminal (e.g., monitoring). The correlation between the discovery signal and the terminal request signal may follow the description above.

[0274] According to one embodiment, in step 2203, the base station that receives the terminal request signal may transmit an on-demand SSB to the terminal in response to the terminal request signal. The mutual relationship between the discovery signal and the on-demand SSB may follow the description above.

[0275] According to one embodiment, the base station that transmitted the on-demand SSB may transmit the SSB in step 2204. For example, the SSB may include at least one of a synchronization signal or a PBCH.

[0276] According to one embodiment, in step 2205, the base station may transmit a SIB PDCCH and a SIB PDSCH for transmitting the SIB. The SIB may include cell-common control information related to transmission and reception. For example, the SIB may include control information related to random access, control information related to paging, and / or common control information for various physical channels.

[0277] According to one embodiment, in step 2206, the base station may proceed with a random access procedure based on a request from the terminal. For example, the terminal may transmit a random access preamble to the base station, and the base station may transmit a RAR to the terminal in response to the random access preamble.

[0278] The steps described above may be modified, omitted, changed in order, or undesired steps may be added to carry out the present invention.

[0279] FIG. 23 is a drawing showing an example of a terminal transceiver in a wireless communication system according to an embodiment of the present disclosure. For convenience of explanation, devices not directly related to the present disclosure may be omitted from illustration and description.

[0280] Referring to FIG. 23, a terminal according to one embodiment may include a transmitter (2304) comprising an uplink transmission processing block (2301), a multiplexer (2302), and a transmission RF block (2303), a receiver (2308) comprising a downlink reception processing block (2305), a demultiplexer (2306), and a reception RF block (2307), and / or a control unit (2309). The control unit (2309) may control each of the constituent blocks of the receiver (2308) for receiving a data channel or control channel transmitted by a base station as described above, and each of the constituent blocks of the transmitter (2304) for transmitting an uplink signal.

[0281] The terminal of FIG. 23 of the present disclosure may correspond to the terminal of FIG. 1 to FIG. 22.

[0282] According to one embodiment, the uplink transmission processing block (2301) in the transmitting unit (2304) of the terminal can generate a signal to be transmitted by performing processes such as channel coding and / or modulation. The signal generated by the uplink transmission processing block (2301) can be multiplexed with other uplink signals by a multiplexer (2302), then processed by a transmitting RF block (2303), and then transmitted to a base station.

[0283] According to one embodiment, the receiving unit (2308) of the terminal can demultiplex a signal received from a base station and distribute it to each downlink receiving processing block. The downlink receiving processing block (2305) can obtain control information or data transmitted by the base station by performing processes such as demodulation and / or channel decoding on the downlink signal of the base station. The receiving unit (2308) of the terminal can apply the output result of the downlink receiving processing block to the control unit (2309) to support the operation of the control unit (2309).

[0284] FIG. 24 is a block diagram showing an example of the configuration of a terminal according to one embodiment of the present disclosure.

[0285] Referring to FIG. 24, the terminal of the present disclosure may include at least one of a processor (2430), a transceiver (2410), or a memory (2420). However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more components or fewer components than the components described above. Furthermore, the processor (2430), the transceiver (2410), and the memory (2420) may be implemented in the form of a single chip. According to one embodiment, the transceiver (2410) of FIG. 24 may include the transceiver (2304) and / or receiver (2308) of FIG. 23. Additionally, the processor (2430) of FIG. 24 may include the control unit (2309) of FIG. 23.

[0286] According to one embodiment, the processor (2430) can control a series of processes that allow the terminal to operate according to the embodiments of the present disclosure described above. For example, according to the embodiments of the present disclosure, the components of the terminal can be controlled to perform a transmission and reception method of the terminal according to a discovery signal of a base station. The processor (2430) may include at least one processor, and the processor (2430) can perform a transmission operation and / or a reception operation of the terminal in a wireless communication system applying the operation of the present disclosure described above by executing a program stored in memory (2420).

[0287] According to one embodiment, the transceiver (2410) can transmit and / or receive signals with a base station. The signals transmitted and received with the base station may include control information and data. The transceiver (2410) may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts the frequency. However, this is merely an example, and the components of the transceiver (2410) are not limited to an RF transmitter and an RF receiver. Additionally, the transceiver (2410) can receive a signal through a wireless channel and output it to a processor (2430), and transmit the signal output from the processor (2430) through a wireless channel.

[0288] According to one embodiment, the memory (2420) may store programs and data necessary for the operation of the terminal. Additionally, the memory (2420) may store control information or data included in signals transmitted and received by the terminal. The memory (2420) may be composed of a storage medium or a combination of storage media such as ROM (read-only memory), RAM (random access memory), a hard disk, a CD-ROM, and a DVD. Additionally, there may be multiple memory (2420). According to one embodiment, the memory (2420) may store a program for performing the transmission and reception operation of the terminal according to the discovery signal of the base station, which is one of the embodiments of the present disclosure described above.

[0289] FIG. 25 is a block diagram showing an example of the configuration of a base station according to one embodiment of the present disclosure.

[0290] As illustrated in FIG. 25, the base station of the present disclosure may include at least one of a processor (2530), a transceiver (2510), or a memory (2520). However, the components of the base station are not limited to the examples described above. For example, the base station may include more components or fewer components than the components described above. In addition, the processor (2530), the transceiver (2510), and the memory (2520) may be implemented in the form of a single chip.

[0291] The base station of FIG. 25 of the present disclosure may correspond to the base station of FIG. 1 to FIG. 24.

[0292] According to one embodiment, the processor (2530) can control a series of processes to enable the base station to operate according to the embodiments of the present disclosure described above. For example, the components of the base station can be controlled to perform a method of scheduling a terminal according to the discovery signal of the base station according to the embodiments of the present disclosure. For example, the processor (2530) may include at least one processor, and the processor (2530) can perform a method of scheduling a terminal according to the frequency instruction of the base station of the present disclosure described above by executing a program stored in memory (2520).

[0293] According to one embodiment, the transceiver (2510) can transmit and / or receive a signal with a terminal. The signal transmitted and / or received with the terminal may include control information and data. The transceiver (2510) may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts the frequency. However, this is merely an example, and the components of the transceiver (2510) are not limited to an RF transmitter and an RF receiver. Additionally, the transceiver (2510) may receive a signal through a wireless channel and output it to a processor (2530), and transmit the signal output from the processor (2530) through a wireless channel.

[0294] According to one embodiment, the memory (2520) may store programs and data necessary for the operation of the base station. Additionally, the memory (2520) may store control information or data included in signals transmitted and received by the base station. The memory (2520) may be composed of a storage medium or a combination of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD. Additionally, there may be multiple memory (2520). According to one embodiment, the memory (2520) may store a program for performing a method of scheduling a terminal according to the discovery signal of the base station, which is one of the embodiments of the present disclosure described above.

[0295] In the specific embodiments of the present disclosure described above, the components included in the present disclosure are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural, it may be composed of a singular form, and even if a component is expressed in the singular form, it may be composed of a plural form.

[0296] Meanwhile, the present specification and drawings disclose preferred embodiments of the present disclosure. Although specific terms have been used, they are used merely in a general sense to facilitate the explanation of the technical content of the present disclosure and to aid in understanding the invention, and are not intended to limit the scope of the present disclosure. It is obvious to those skilled in the art that, in addition to the embodiments disclosed herein, other variations based on the technical concept of the present disclosure are possible. Furthermore, each of the above embodiments may be combined and operated as needed. For example, the first, second, and third embodiments may be implemented independently, or at least one of the embodiments may be combined and implemented.

[0297] Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, it is understood that various modifications are possible within the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be defined by the claims set forth below as well as equivalents thereof.

Claims

1. In a method performed by UE (user equipment), A step of receiving a discovery signal from a base station for a cell associated with said base station; A step of transmitting a request associated with an SSB (synchronization signal block) to the base station based on the discovery signal; and The method includes the step of receiving the SSB from the base station, A method in which the first period of the discovery signal is longer than the second period of the SSB.

2. In Claim 1, The method further includes the step of receiving a first SSB from the base station as a response to the request, and The above SSB is a method received from the base station after the above first SSB.

3. In Claim 3, The bandwidth (BW) of the above discovery signal is the same as or partially overlaps with the bandwidth of the first SSB, and The first SSB is received from the base station after a first offset has elapsed from the discovery signal, and A method in which the above request is transmitted to the base station after a second offset has elapsed from the discovery signal.

4. In Claim 1, The above SSB is received from the base station based on the above request, and The above method is: A step of receiving a system information block (SIB) from the base station based on a master information block (MIB) associated with the SSB; and A method further comprising the step of transmitting a random access preamble based on the SIB to the base station.

5. In a method performed by a base station, A step of transmitting a discovery signal for a cell associated with the base station to the UE (user equipment); Receiving a request associated with an SSB (synchronization signal block) from the UE based on the discovery signal; and The method includes the step of transmitting the SSB to the above UE, A method in which the first period of the discovery signal is longer than the second period of the SSB.

6. In Claim 5, The method further includes the step of transmitting a first SSB to the above UE as a response to the request, The above SSB is transmitted to the UE after the above first SSB, in a method.

7. In Claim 6, The bandwidth (BW) of the above discovery signal is the same as or partially overlaps with the bandwidth of the first SSB, and The first SSB is transmitted to the UE after a first offset has elapsed from the discovery signal, and A method in which the above request is received from the UE after a second offset has elapsed from the discovery signal.

8. In Claim 5, The above SSB is transmitted to the UE based on the above request, and The above method is: A step of transmitting a system information block (SIB) to the UE based on a master information block (MIB) associated with the SSB; and A method further comprising the step of receiving a random access preamble based on the SIB from the above UE.

9. Regarding UE (user equipment): At least one transceiver; At least one processor communicatively coupled to the above at least one transceiver; and It includes at least one memory that is communicationally coupled to the above at least one processor and stores instructions, and The above instructions are executed individually or in any combination by the above at least one processor, so that the UE: Receive a discovery signal from a base station for a cell associated with said base station, and Transmit a request associated with an SSB (synchronization signal block) to the base station based on the discovery signal, and To receive the SSB from the above base station, UE, the first period of the above discovery signal is longer than the second period of the above SSB.

10. In Claim 9, The above commands are the above UE: To receive a first SSB from the above base station as a response to the above request, and The above SSB is a UE received from the base station after the above 1 SSB.

11. In Claim 10, The bandwidth (BW) of the above discovery signal is the same as or partially overlaps with the bandwidth of the first SSB, and The first SSB is received from the base station after a first offset has elapsed from the discovery signal, and The above request is transmitted to the base station after a second offset has elapsed from the discovery signal, the UE.

12. In Claim 9, The above SSB is received from the base station based on the above request, and The above commands are the above UE: From the above base station, receive a system information block (SIB) based on a master information block (MIB) associated with the SSB, and A UE that instructs the base station to transmit a random access preamble based on the SIB.

13. Regarding base stations: At least one transceiver; At least one processor communicatively coupled to the above at least one transceiver; and It includes at least one memory that is communicationally coupled to the above at least one processor and stores instructions, and The above instructions are executed individually or in any combination by the above at least one processor, so that the base station: Transmitting a discovery signal for a cell associated with the base station to the UE (user equipment), and Receive a request associated with an SSB (synchronization signal block) from the above UE based on the discovery signal, and Instruct the above UE to transmit the above SSB, and A base station in which the first period of the above discovery signal is longer than the second period of the above SSB.

14. In Claim 13, The above commands are the above base station: Instruct the above UE to transmit a first SSB as a response to the above request, and The above SSB is a base station that is transmitted to the UE after the above 1 SSB.

15. In Claim 14, The bandwidth (BW) of the above discovery signal is the same as or partially overlaps with the bandwidth of the first SSB, and The first SSB is transmitted to the UE after a first offset has elapsed from the discovery signal, and The above request is received from the base station after a second offset has elapsed from the discovery signal.

Images