Method and device for random access in wireless communication system comprising multiple carriers

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method performed by a terminal in a communication system according to an embodiment of the present disclosure may comprise the steps of: receiving, from a base station, a synchronization signal block (SSB) in a first downlink frequency band; receiving, from the base station on the basis of the SSB, physical downlink control information (PDCCH) for scheduling a system information block (SIB); receiving the SIB from the base station on the basis of the PDCCH; and transmitting a physical random-access channel (PRACH) in a first uplink frequency band on the basis of the SIB, wherein the SIB includes control information for at least one of a plurality of downlink frequency bands and control information for at least one of a plurality of uplink frequency bands, and a transmission power of the PRACH is associated with control information of the first downlink frequency band and control information of the first uplink frequency band.

Description

Random access method and device in a wireless communication system consisting of multiple carriers

[0001] The present disclosure relates to a communication method of a wireless communication system, and to a method and device for defining efficient frequency use and transmission and reception operations of a terminal.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band, such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave), such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), methods are being considered to achieve even faster transmission speeds and even less ultra-low latency compared to 5G mobile communication technology.

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

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

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

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

[0007] With the commercialization of 5G mobile communication systems, an explosive increase in connected devices will be connected to communication networks, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0008] In addition, the development of these 5G mobile communication systems can serve as the basis for the development of new waveforms for coverage guarantee of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology for improving the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence)-based communication technology that utilizes AI from the design stage and internalizes end-to-end AI support functions to realize system optimization, and next-generation distributed computing technology that realizes services with complexity that exceeds the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources.

[0009] The disclosed embodiments provide a device and method capable of effectively providing mobile communication services. Specifically, a base station and a terminal can effectively perform random access procedures in a multi-carrier system.

[0010] The technical problems to be achieved in the disclosed embodiments are not limited to those mentioned above, and other technical problems not mentioned can be considered by a person having ordinary skill in the art from the various embodiments of the present disclosure described below.

[0011] A method performed by a terminal of a communication system according to one embodiment of the present disclosure includes the steps of receiving a synchronization signal block (SSB) from a base station in a first downlink frequency band, receiving a physical downlink control information (PDCCH) for scheduling a system information block (SIB) from the base station based on the SSB, receiving the SIB from the base station based on the PDCCH, and performing transmission of a physical random access channel (PRACH) in a first uplink frequency band based on the SIB, wherein the SIB includes control information for at least one of a plurality of downlink frequency bands and control information for at least one of a plurality of uplink frequency bands, and a transmission power of the PRACH may be associated with the control information of the first downlink frequency band and the control information of the first uplink frequency band.

[0012] A method performed by a base station of a communication system according to one embodiment of the present disclosure includes the steps of transmitting a synchronization signal block (SSB) to a terminal in a first downlink frequency band, transmitting a physical downlink control information (PDCCH) scheduling a system information block (SIB) to the terminal according to the SSB, transmitting the SIB according to the PDCCH, and receiving a physical random access channel (PRACH) transmitted in the first uplink frequency band according to the SIB, wherein the SIB includes control information for at least one of a plurality of downlink frequency bands and control information for at least one of a plurality of uplink frequency bands, and a transmission power of the PRACH may be associated with the control information of the first downlink frequency band and the control information of the first uplink frequency band.

[0013] According to one embodiment of the present disclosure, a terminal of a communication system includes at least one transceiver, at least one processor communicatively connected to the at least one transceiver, and a memory that stores instructions communicatively connected to the at least one processor and executable individually or in any combination by the at least one processor, such that the terminal receives a synchronization signal block (SSB) from a base station in a first downlink frequency band, receives a physical downlink control information (PDCCH) from the base station that schedules a system information block (SIB) based on the SSB, receives the SIB from the base station based on the PDCCH, and transmits a physical random access channel (PRACH) in a first uplink frequency band based on the SIB, wherein the SIB includes control information for at least one of a plurality of downlink frequency bands and control information for at least one of a plurality of uplink frequency bands, and a transmission power of the PRACH may be associated with the control information of the first downlink frequency band and the control information of the first uplink frequency band.

[0014] According to one embodiment of the present disclosure, a base station of a communication system includes at least one transceiver, at least one processor communicatively connected to the at least one transceiver, and a memory communicatively connected to the at least one processor and executable individually or in any combination by the at least one processor, the memory storing instructions that cause the base station to transmit a synchronization signal block (SSB) to a terminal in a first downlink frequency band, transmit a physical downlink control information (PDCCH) scheduling a system information block (SIB) according to the SSB to the terminal, transmit the SIB according to the PDCCH, and perform reception of a physical random access channel (PRACH) transmitted in the first uplink frequency band according to the SIB, wherein the SIB includes control information for at least one of a plurality of downlink frequency bands and control information for at least one of a plurality of uplink frequency bands, and a transmission power of the PRACH may be associated with the control information of the first downlink frequency band and the control information of the first uplink frequency band.

[0015] Embodiments of the present disclosure provide a transmission / reception device and method for a terminal and a base station that enhance frequency utilization efficiency in a mobile communication system. Specifically, according to at least one embodiment of the present disclosure, a base station and a terminal in a multi-carrier system can effectively perform a random access procedure.

[0016] The effects that can be obtained from the disclosed embodiments are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly derived and understood by a person having ordinary skill in the art based on the detailed description below.

[0017] FIG. 1 is a diagram showing the basic structure of a time-frequency resource domain of a wireless communication system according to one embodiment of the present disclosure.

[0018] FIG. 2 is a diagram illustrating a random access procedure according to one embodiment of the present disclosure.

[0019] FIG. 3 is a diagram illustrating a procedure for a terminal to report terminal capability information to a base station according to one embodiment of the present disclosure.

[0020] FIG. 4 is a diagram showing an example of bandwidth portion settings according to one embodiment of the present disclosure.

[0021] FIG. 5 is a diagram showing the interrelationship between frequency bands and coverage according to one embodiment of the present disclosure.

[0022] FIG. 6 is a diagram showing a frequency relationship according to one embodiment of the present disclosure.

[0023] FIG. 7 is a diagram showing a frequency relationship according to one embodiment of the present disclosure.

[0024] FIG. 8 is a diagram illustrating an example of connecting a downlink frequency and an uplink frequency according to one embodiment of the present disclosure.

[0025] FIG. 9 is a diagram illustrating an example of connecting a downlink frequency and an uplink frequency according to one embodiment of the present disclosure.

[0026] FIG. 10 is a diagram illustrating an example of connecting a downlink frequency and an uplink frequency according to one embodiment of the present disclosure.

[0027] FIG. 11 is a diagram illustrating an example of connecting a downlink frequency and an uplink frequency according to one embodiment of the present disclosure.

[0028] FIG. 12 is a diagram illustrating an example of a random access preamble transmission method of a terminal according to one embodiment of the present disclosure.

[0029] FIG. 13 is a diagram illustrating another example of a random access preamble transmission method of a terminal according to one embodiment of the present disclosure.

[0030] FIG. 14 is a diagram showing an example of a terminal procedure according to one embodiment of the present disclosure.

[0031] FIG. 15 is a diagram illustrating an example of a base station procedure according to one embodiment of the present disclosure.

[0032] FIG. 16 is a diagram showing a terminal transceiver device according to one embodiment of the present disclosure.

[0033] FIG. 17 is a block diagram illustrating the structure of a terminal according to one embodiment of the present disclosure.

[0034] FIG. 18 is a block diagram illustrating the structure of a base station according to one embodiment of the present disclosure.

[0035] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. Furthermore, detailed descriptions of related known functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Furthermore, the terms described below are defined based on their functions in the present disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the overall content of this specification.

[0036] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to ensure that the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0037] At this time, it will be understood that each block of the processing flowchart drawings and combinations of the flowchart drawings can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flowchart block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flowchart block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0038] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0039] Here, the term '~ part' used in this embodiment means software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and the '~ part' performs certain roles. However, the '~ part' is not limited to software or hardware. The '~ part' may be configured to be on an addressable storage medium or may be configured to play one or more processors. Therefore, as an example, the '~ part' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ parts' may be combined into a smaller number of components and '~ parts' or further separated into additional components and '~ parts'. Additionally, the components and '~parts' may be implemented to activate one or more CPUs within a device or secure multimedia card. In addition, in an embodiment, the '~parts' may include one or more processors.

[0040] In the following description of the present disclosure, detailed descriptions of related known functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Hereinafter, embodiments of the present disclosure will be described with reference to the attached drawings.

[0041] The terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, terms referring to various identification information, etc. are provided as examples for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects with equivalent technical meanings may be used.

[0042] In the following description, the terms "physical channel" and "physical signal" may be used interchangeably with data or control signals. For example, while PDSCH (physical downlink shared channel) refers to a physical channel through which data is transmitted, PDSCH can also be used to refer to data. That is, in the present disclosure, the expression "transmitting a physical channel" can be interpreted equivalently to the expression "transmitting data or a signal through a physical channel."

[0043] Hereinafter, in the present disclosure, higher layer signaling refers to a signal transmission method in which a base station transmits a signal to a terminal using a downlink data channel of a physical layer, or from a terminal to a base station using an uplink data channel of a physical layer. Higher layer signaling can be understood as a master information block (MIB), a system information block (SIB), radio resource control (RRC) signaling, or a media access control (MAC) control element (CE).

[0044] For convenience of explanation, this disclosure uses terms and names defined in the 3GPP NR (New Radio: 5th generation mobile communications standard) standard. However, this disclosure is not limited to these terms and names and can be equally applied to systems conforming to other standards. For example, for 6G systems, which are still in the early stages of standardization discussions, the terms and names defined in the 5G system can be generalized and used to describe the operation of the 6G system unless otherwise specified.

[0045] Hereinafter, a base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNodeB, a gNB, an eNodeB, an eNB, a NodeB, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, an IoT device, a sensor, or a multimedia system capable of performing a communication function. Of course, the present invention is not limited to the examples described.

[0046] While existing mobile communication systems have focused on conventional voice / data communications, the 5G system aims to satisfy various services and requirements, such as enhanced Mobile Broadband (eMBB) services to improve existing voice / data communications, ultra-reliable and low latency communication (URLLC) services to provide high reliability / ultra-low latency communications, and massive Machine Type Communication (MTC) services to support large-scale machine-to-machine communications.

[0047] While the transmission bandwidth of a single carrier in 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, the 5G system aims to provide ultra-high-speed data services of up to several Gbps by utilizing a much wider ultra-wide bandwidth. Accordingly, the 5G system is considering an ultra-high frequency band from several GHz up to 100 GHz, where it is relatively easy to secure ultra-wide bandwidth frequencies, as its operating frequency. Additionally, it is possible to secure wide bandwidth frequencies for the 5G system through frequency reallocation or allocation among the frequency bands included in the hundreds of MHz to several GHz used in existing mobile communication systems.

[0048] Ultra-high frequency radio waves, sometimes called millimeter waves (mmWave), have wavelengths on the order of millimeters. However, in ultra-high frequency bands, path loss increases proportionally to the frequency band, reducing the coverage of mobile communication systems.

[0049] To overcome the drawback of reduced coverage in ultra-high frequency bands, beamforming technology is applied. This technology focuses the radiated energy of radio waves toward a predetermined target point using multiple antennas, thereby increasing the transmission range. Specifically, a signal using beamforming technology has a relatively narrow beamwidth, and the radiated energy is concentrated within this narrowed beamwidth, increasing the transmission range. Beamforming technology can be applied to both the transmitter and receiver. In addition to increasing coverage, beamforming technology also reduces interference in areas outside the beamforming direction. For beamforming technology to function properly, accurate measurement and feedback of the transmission and reception beams are required. Beamforming technology can be applied to control channels or data channels that correspond one-to-one between a given terminal and a base station. Furthermore, beamforming can also be applied to common signals transmitted by a base station to multiple terminals within a system, such as synchronization signals, physical broadcast channels (PBCHs), and control and data channels for transmitting system information, to increase coverage. When applying beamforming technology to a common signal, beam sweeping technology, which transmits the signal by changing the beam direction, is additionally applied so that the common signal can reach terminals located at any location within the cell.

[0050] Another requirement for 5G systems is ultra-low latency services, with transmission delays of approximately 1ms between transmitters and receivers. One way to reduce transmission delay is to design a frame structure based on a short Transmission Time Interval (TTI), which is shorter than that of LTE and LTE-A. A TTI is the basic time unit for scheduling, and the TTI of existing LTE and LTE-A systems is 1ms, which corresponds to the length of one subframe. For example, in 5G systems, to meet the requirements for ultra-low latency services, shorter TTIs such as 0.5ms, 0.25ms, and 0.125ms are possible, which are shorter than those of existing LTE and LTE-A systems.

[0051] FIG. 1 is a diagram illustrating the basic structure of a time-frequency resource domain of a 5G system according to one embodiment of the present disclosure. That is, FIG. 1 is a diagram illustrating the basic structure of a time-frequency resource domain, which is a radio resource domain through which data or control channels of a 5G system are transmitted.

[0052] Referring to Figure 1, the horizontal axis in Figure 1 represents the time domain and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain of the 5G system is an OFDM (Orthogonal Frequency Division Multiplexing) symbol. The dog symbols (102) come together to form one slot (106), A plurality of slots can be gathered to form a subframe (105). The length of one subframe (105) is 1.0 ms, and 10 subframes can be gathered to form a 10 ms frame (114). The minimum transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission bandwidth is a total of N BW It can be composed of a subcarrier (104).

[0053] The basic unit of resources in the time-frequency domain is a Resource Element (RE) (112), which can be represented by an OFDM symbol index and a subcarrier index. A Resource Block (RB or Physical Resource Block, PRB) is a resource block in the frequency domain. can be defined as a series of consecutive subcarriers (110). In the 5G system = 12, and the data rate can increase in proportion to the number of RBs scheduled to the terminal.

[0054] In a 5G system, a base station can map data in RB units and perform scheduling on RBs, which typically constitute a slot for a given terminal. That is, in a 5G system, the basic time unit for scheduling may be a slot, and the basic frequency unit for scheduling may be an RB.

[0055] Number of OFDM symbols It is determined by the length of the cyclic prefix (CP) added to each symbol to prevent interference between symbols. For example, if the normal CP is applied, = 14, when Extended CP is applied = 12. Extended CP can be applied to systems with relatively long transmission distances compared to general CP, allowing for maintaining orthogonality between symbols. In the case of general CP, since the ratio of CP length to symbol length is maintained at a constant value, the overhead due to CP can be maintained constant regardless of the subcarrier spacing. That is, if the subcarrier spacing is small, the symbol length becomes longer, and thus the CP length can also become longer. Conversely, if the subcarrier spacing is large, the symbol length becomes shorter, and thus the CP length can be reduced. The symbol length and CP length can be inversely proportional to the subcarrier spacing.

[0056] In 5G systems, various frame structures can be supported by adjusting the subcarrier spacing to meet diverse services and requirements. For example,

[0057] - From the perspective of the operating frequency band, the larger the subcarrier spacing, the more advantageous it is for recovering phase noise in the high-frequency band.

[0058] - From a transmission time perspective, if the subcarrier spacing is large, the symbol length in the time domain becomes shorter, and consequently, the slot length becomes shorter, which is advantageous for supporting ultra-low delay services such as URLLC.

[0059] - From a cell size perspective, a longer CP length allows for larger cells to be supported, so a smaller subcarrier spacing allows for relatively larger cells to be supported. In mobile communications, a cell is a concept that refers to the area covered by a single base station.

[0060] Subcarrier spacing, CP length, etc. are essential information for OFDM transmission and reception. Smooth transmission and reception is possible only when the base station and terminal recognize the subcarrier spacing, CP length, etc. as common values. shows the relationship between the subcarrier spacing configuration (μ), subcarrier spacing (Δf), and CP length supported by the 5G system.

[0061]

[0062] shows the number of symbols per slot for each subcarrier spacing setting (μ) in the case of the general CP. ), number of slots per frame ( ), number of slots per subframe ( ) is indicated.

[0063]

[0064] 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 ( ) is indicated.

[0065]

[0066] 5G systems can satisfy diverse user requirements through coexistence or dual-mode operation with existing LTE and / or LTE-A (hereinafter referred to as LTE / LTE-A) systems. For example, existing LTE / LTE-A systems can provide stable system operation to terminals, while 5G systems can provide enhanced services to terminals. Therefore, the 5G system's frame structure must at least include the LTE / LTE-A frame structure or essential parameter set (subcarrier spacing = 15 kHz).

[0067] For example, comparing a frame structure with a subcarrier spacing setting μ=0 (hereinafter referred to as frame structure A) and a frame structure with a subcarrier spacing setting μ=1 (hereinafter referred to as frame structure B), compared to frame structure A, frame structure B shows that the subcarrier spacing and RB size are twice as large, and the slot length and symbol length are twice as small. In the case of frame structure B, two slots can constitute one subframe, and 20 subframes can constitute one frame.

[0068] Generalizing the frame structure of a 5G system provides high scalability by ensuring that essential parameters—subcarrier spacing, CP length, and slot length—have integer multiple relationships for each frame structure. Furthermore, a fixed-length subframe of 1 ms can be defined to represent a reference time unit independent of the frame structure.

[0069] The frame structure of a 5G system can be applied to various scenarios. From a cell size perspective, a longer CP length can support larger cells, so frame structure A can support relatively larger cells than frame structure B. From an operating frequency band perspective, a larger subcarrier spacing is advantageous for phase noise recovery in high-frequency bands, so frame structure B can support relatively higher operating frequencies than frame structure A. From a service perspective, a shorter slot length, which is the basic time unit of scheduling, is advantageous for supporting ultra-low-latency services such as URLLC, so frame structure B can be relatively more suitable for URLLC services than frame structure A.

[0070] Similar to the coexistence of 5G and LTE / LTE-A mentioned above, system design for coexistence of 6G, which will arrive in the future as communication systems evolve, and existing systems such as 5G or LTE / LTE-A may be required.

[0071] In the following description of the present disclosure, uplink (UL) may refer to a wireless link through which a terminal transmits data or a control signal to a base station, and downlink (DL) may refer to a wireless link through which a base station transmits data or a control signal to a terminal.

[0072] During the initial access phase, when a terminal first connects to the system, the terminal can synchronize downlink time and frequency using a synchronization signal transmitted by the base station through cell search and acquire a cell identifier (cell ID). Using the acquired cell ID, the terminal can receive a Physical Broadcast Channel (PBCH) and acquire a Master Information Block (MIB), which is essential system information, from the PBCH. The MIB may include the following information:

[0073] MIB ::= SEQUENCE { systemFrameNumber BIT STRING (SIZE (6)), subCarrierSpacingCommon ENUMERATED {scs15or60, scs30or120}, ssb-SubcarrierOffset INTEGER (0..15), dmrs-TypeA-Position ENUMERATED {pos2, pos3}, pdcch-ConfigSIB1 PDCCH-ConfigSIB1, cellBarred ENUMERATED {barred, notBarred}, intraFreqReselection ENUMERATED {allowed, notAllowed}, spare BIT STRING (SIZE (1))}

[0074] For example, the essential system information may include at least one of information for receiving system information, such as information on the time domain and / or frequency domain location of a synchronization signal received by the terminal, control information for the terminal to receive 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 on whether the cell is accessible, and information on the SCS of the cell. The essential system information may be referred to as system information. Additionally, the terminal may obtain control information related to transmission and reception common to cells by receiving system information (System Information Block, SIB) transmitted by the base station. Cell-common transmission and reception-related control information may include random access-related control information, paging-related control information, common control information for various physical channels and signals (at least one of an uplink control channel, an uplink data channel, a downlink control channel, and a downlink data channel, a physical signal for obtaining uplink channel state information, a physical signal for obtaining downlink channel state information, a physical signal for demodulating a physical channel, etc.). The control information may be configuration information for each channel or signal. The system information may be referred to as, for example, SIB1 or RMSI (remaining minimum system information).

[0075] The synchronization signal is a signal that serves as a reference for cell search, and the subcarrier spacing can be applied to suit the channel environment, such as phase noise, for each frequency band. In the case of data channels or control channels, the subcarrier spacing can be applied differently depending on the service type in order to support various services as described above. In the 5G system, the combination consisting of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH) is called an SS / PBCH block or SSB.

[0076] In addition to the initial connection procedure described above, the terminal may also receive SSBs to determine whether the radio link quality of the current cell is maintained at a certain level or higher. Furthermore, in a procedure where the terminal performs a handover from the current cell to an adjacent cell, the terminal may also receive SSBs from the adjacent cell to determine the radio link quality of the adjacent cell and obtain time / frequency synchronization with the adjacent cell.

[0077] After the terminal acquires MIB and system information from the base station through the initial access procedure, the terminal can perform a random access procedure to transition the link with the base station to the connected state (or RRC_CONNECTED state). Upon completion of the random access procedure, the terminal transitions to the connected state, enabling one-to-one communication between the base station and the terminal. The random access procedure is described in detail below with reference to FIG. 2.

[0078] FIG. 2 is a diagram illustrating a random access procedure according to one embodiment of the present disclosure.

[0079] Referring to FIG. 2, in the first step (210) of the random access procedure, the terminal transmits a random access preamble to the base station. The random access preamble, which is the first transmission message of the terminal in the random access procedure, may be referred to as message 1. The base station can measure the transmission delay value between the terminal and the base station from the random access preamble and synchronize the uplink. At this time, the terminal can arbitrarily select which random access preamble to use within the random access preamble set given in advance by system information. In addition, the initial transmission power of the random access preamble can be determined according to the path loss (PL) between the terminal and the base station measured by the terminal. In addition, the terminal can determine the transmission beam direction of the random access preamble from the synchronization signal received from the base station and transmit the random access preamble.

[0080] In the second step (220), the base station transmits a message including an uplink transmission timing adjustment command to the terminal based on the transmission delay value measured from the random access preamble received in the first step (210). The terminal receives control information for scheduling the message on a downlink control channel and receives the message on a downlink data channel based on the control information. The message transmitted in the second step may be referred to as message 2, or a response to the random access preamble, or a random access response (RAR). In addition, the base station may transmit the message by including, as scheduling information, an uplink resource to be used by the terminal to transmit a response message (message 3) to message 2 and a power control command to be applied to the response message. The scheduling information may include control information for the uplink transmission beam of the terminal. In addition, 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 above-described information may be included in message 2.

[0081] 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 first step (210) can be performed again. If the first step (210) is performed again, the terminal can increase the probability of the base station receiving the random access preamble by transmitting it while increasing the transmission power of the random access preamble by a predetermined step (power ramping).

[0082] In the third step (230), the terminal transmits uplink data (message 3) including its terminal ID to the base station through an uplink data channel (Physical Uplink Shared Channel, PUSCH) using 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). In addition, 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 mean the first uplink data signal that the terminal transmits to the base station after transmitting the random access preamble. For example, the message 3 may include a higher layer message for the terminal to access the network.

[0083] In step 4 (240), if the base station determines that the terminal has performed random access without collision with other terminals, it transmits data (message 4) including 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 can determine that the random access has been successful. In addition, the terminal can transmit HARQ-ACK information indicating whether message 4 was successfully received to the base station through the uplink control channel (Physical Uplink Control Channel, PUCCH).

[0084] If the data transmitted by the terminal in step 3 (230) collides with data from another terminal, causing the base station to fail to receive a data signal from the terminal, the base station may not transmit any more data to the terminal. Accordingly, if the terminal fails to receive the data transmitted from the base station in step 4 (240) within a certain period of time, the random access procedure may be determined to have failed and may be restarted from step 1 (210).

[0085] The four-step random access procedure described above is merely an example, and the information between the terminal and the base station described above may also be transmitted via messages other than the four-step message described above. For example, the terminal may simultaneously or sequentially transmit to the base station one or more messages containing at least one of the information in message 1 and 3, and the base station may simultaneously or sequentially transmit to the terminal one or more messages containing at least one of the information in message 2 and 4.

[0086] Upon successful completion of the random access procedure, the terminal transitions to the connected state, enabling one-to-one communication between the base station and the terminal. The base station receives UE capability information from the connected terminal and can adjust scheduling based on the UE capability information. Through UE capability information, the terminal can inform the base station whether it supports a given function and the maximum allowable value of the function supported by the terminal. Therefore, the UE capability information reported by each terminal to the base station may have different values ​​for each terminal.

[0087] For example, a terminal may report UE capability information including at least a portion of the following control information to a base station as UE capability information.

[0088] - Control information related to frequency bands supported by the terminal

[0089] - Control information related to channel bandwidth supported by the terminal

[0090] - Control information related to the maximum modulation method supported by the terminal

[0091] - Control information related to the maximum number of beams supported by the terminal

[0092] - Control information related to the maximum number of layers supported by the terminal

[0093] - Control information related to CSI reporting supported by the terminal

[0094] - Control information on whether the terminal supports frequency hopping

[0095] - Bandwidth-related control information when supporting carrier aggregation (CA)

[0096] - Control information on whether cross carrier scheduling is supported when carrier aggregation is supported.

[0097] FIG. 3 is a diagram illustrating a procedure for a terminal to report terminal capability information to a base station according to one embodiment of the present disclosure.

[0098] Referring to FIG. 3, at step 310, the base station (302) can transmit a UE capability information request message to the terminal (301). In response to the base station's request for UE capability information, the terminal transmits UE capability information to the base station at step 320.

[0099] Next, the bandwidth part (BWP) setting in the 5G communication system will be explained in detail with reference to the drawing.

[0100] Figure 4 is a diagram illustrating an example of bandwidth portion settings in a 5G communication system.

[0101] FIG. 4 shows an example in which the UE bandwidth (400) is set to two bandwidth portions, namely, bandwidth portion #1 (BWP#1) (401) and bandwidth portion #2 (BWP#2) (402). The base station can set one or more bandwidth portions to the UE, and can set the information in below for each bandwidth portion.

[0102] BWP ::= SEQUENCE { bwp-Id BWP-Id, locationAndBandwidth INTEGER (1..65536), subcarrierSpacing ENUMERATED {n0, n1, n2, n3, n4, n5}, cyclicPrefix ENUMERATED { extended}}

[0103] Of course, the above example is not limited, and in addition to the above configuration information, various parameters related to the bandwidth portion can be configured for the terminal. The above information can be transmitted from the base station to the terminal via upper layer signaling, for example, RRC (Radio Resource Control) signaling. At least one bandwidth portion among the configured one or more bandwidth portions can be activated. Whether or not the configured bandwidth portion is activated can be semi-statically transmitted from the base station to the terminal via RRC signaling or dynamically transmitted via DCI.

[0104] According to some embodiments, a terminal before RRC connection can receive configuration information for an initial bandwidth portion (Initial BWP) for initial access from a base station through a Master Information Block (MIB). More specifically, during the initial access phase, the terminal can receive configuration information for a control resource set (CORESET) and a search space, where a PDCCH for receiving system information (System Information Block) required for initial access can be transmitted, through the MIB. The control space and search space configured by the MIB can each be regarded as identifier (ID) 0 (CORESET 0, Search Space 0). The base station can notify the terminal of configuration information such as frequency allocation information, time allocation information, and subcarrier spacing settings for control space #0 through the MIB. In addition, the base station can notify the terminal of configuration information for a monitoring cycle and monitoring occasion for control space #0, i.e., configuration information for search space #0, through the MIB. The terminal may consider the frequency range set as control area #0 obtained from the MIB as the initial bandwidth portion for initial connection. At this time, the identifier (ID) of the initial bandwidth portion may be considered as 0.

[0105] The settings for the bandwidth supported by the above 5G can be used for various purposes.

[0106] In some embodiments, when the bandwidth supported by a terminal is smaller than the system bandwidth, this can be supported through bandwidth portion configuration. For example, the base station can configure the bandwidth portion frequency location (configuration information 2) for the terminal, thereby allowing the terminal to transmit and receive data at a specific frequency location within the system bandwidth.

[0107] Additionally, in some embodiments, a base station may configure multiple bandwidth segments for a terminal to support different subcarrier spacing settings. For example, to support data transmission and reception using both 15 kHz and 30 kHz subcarrier spacing for a given terminal, two bandwidth segments may be configured with subcarrier spacings of 15 kHz and 30 kHz, respectively. The different bandwidth segments may be frequency-division multiplexed (FDM), and when data is to be transmitted and received using a specific subcarrier spacing, the bandwidth segment configured with the corresponding subcarrier spacing may be activated.

[0108] Furthermore, in some embodiments, the base station may configure bandwidth portions with different bandwidth sizes for the terminal for the purpose of reducing power consumption of the terminal. For example, if the terminal supports a very large bandwidth, for example, 100 MHz, and constantly transmits and receives data using that bandwidth, very large power consumption may occur. In particular, monitoring unnecessary downlink control channels using a large bandwidth of 100 MHz in a situation where there is no traffic may be very inefficient in terms of power consumption. To reduce power consumption of the terminal, the base station may configure a bandwidth portion with a relatively small bandwidth, for example, 20 MHz, for the terminal. In a situation where there is no traffic, the terminal can perform monitoring operations in the 20 MHz bandwidth portion, and when data is generated, it can transmit and receive data using the 100 MHz bandwidth portion according to the instructions of the base station.

[0109] In the method for setting the bandwidth portion, terminals prior to RRC connection (Connected) can receive configuration information for the initial bandwidth portion (Initial BWP) through the MIB during the initial access phase. More specifically, the terminal can receive a control region (i.e., CORESET) for a downlink control channel on which a DCI scheduling a System Information Block (SIB) can be transmitted from the MIB of the PBCH (Physical Broadcast Channel). The bandwidth of the control region set by the MIB can be regarded as the initial bandwidth portion, and the terminal can receive the PDSCH (Physical Downlink Shared Channel) on which the SIB is transmitted through the set initial bandwidth portion. In addition to receiving the SIB, the initial bandwidth portion can also be utilized for paging and random access.

[0110] Next, we will specifically explain downlink control information (DCI) in the 5G system.

[0111] In a 5G system, scheduling information for uplink data (or physical uplink shared channel (PUSCH)) or downlink data (or physical downlink shared channel (PDSCH)) can be transmitted from a base station to a terminal via DCI. The terminal can monitor a DCI format for fallback and a DCI format for non-fallback for the PUSCH or PDSCH. The fallback DCI format can be composed of fixed fields predefined between the base station and the terminal, and the non-fallback DCI format can include configurable fields.

[0112] DCI can be transmitted through the Physical Downlink Control Channel (PDCCH) after going through the channel coding and modulation process. A Cyclic Redundancy Check (CRC) is attached to the DCI message payload, and the CRC can be scrambled with the UE's identity identifier (e.g., Radio Network Temporary Identifier, RNTI). Different RNTIs can be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control command, or random access response. That is, the RNTI is not transmitted explicitly, but is included in the CRC calculation process. When the UE receives a DCI message transmitted on the PDCCH, it verifies the CRC using the assigned RNTI. If the CRC verification result is correct, the UE knows that the message has been transmitted to the UE.

[0113] For example, a DCI scheduling a PDSCH for system information may be scrambled with SI-RNTI. A DCI scheduling a PDSCH for a RAR message may be scrambled with RA-RNTI. A DCI scheduling a PDSCH for a paging message may be scrambled with P-RNTI. A DCI notifying a Slot Format Indicator (SFI) may be scrambled with SFI-RNTI. A DCI notifying a Transmit Power Control (TPC) may be scrambled with TPC-RNTI. A DCI scheduling a UE-specific PDSCH or PUSCH may be scrambled with C-RNTI (Cell RNTI).

[0114] The base station can operate by applying a predetermined DCI format depending on whether the DCI is scheduling information for downlink data (downlink assignment) for the terminal to be scheduled, scheduling information for uplink data (uplink grant), or DCI for purposes other than data scheduling, such as power control.

[0115] The base station can transmit downlink data to the terminal via the Physical Downlink Shared Channel (PDSCH), a physical channel for downlink data transmission. Scheduling information, such as the specific mapping location in the time and frequency domains of the PDSCH, modulation scheme, HARQ-related control information, and power control information, can be communicated to the terminal by the base station via DCI related to downlink data scheduling information among the DCI transmitted via the PDCCH.

[0116] A terminal can transmit uplink data to a base station via the Physical Uplink Shared Channel (PUSCH), a physical channel for uplink data transmission. Scheduling information, such as specific mapping locations in the time and frequency domains of the PUSCH, modulation schemes, HARQ-related control information, and power control information, can be provided to the terminal by the base station via DCI related to uplink data scheduling information, among the DCIs transmitted via the PDCCH.

[0117] The time-frequency resources to which the PDCCH is mapped are called a Control Resource Set (CORESET). A CORESET can be configured for all or part of the frequency resources of the bandwidth supported by the UE in the frequency domain. In the time domain, it can be configured with one or more OFDM symbols, which can be defined as the CORESET length (Control Resource Set Duration). The base station can configure one or more CORESETs to the UE through higher layer signaling (e.g., System Information, Master Information Block (MIB), Radio Resource Control (RRC) signaling). Configuring a CORESET to the UE may mean providing information such as a CORESET identifier (Identity), the frequency location of the CORESET, and the symbol length of the CORESET. The information that the base station provides to the UE to configure the CORESET may include at least some of the information included in .

[0118] ControlResourceSet ::= SEQUENCE { controlResourceSetId ControlResourceSetId, frequencyDomainResources BIT STRING (SIZE (45)), duration INTEGER (1..maxCoReSetDuration), cce-REG-MappingType CHOICE { interleaved SEQUENCE { reg-BundleSize ENUMERATED {n2, n3, n6}, interleaverSize ENUMERATED {n2, n3, n6}, shiftIndex INTEGER(0..maxNrofPhysicalResourceBlocks-1) OPTIONAL -- Need S }, nonInterleaved NULL }, precoderGranularity ENUMERATED {sameAsREG-bundle, allContiguousRBs}, tci-StatesPDCCH-ToAddList SEQUENCE(SIZE (1..maxNrofTCI-StatesPDCCH)) OF TCI-StateId OPTIONAL, -- Cond NotSIB1-initialBWP tci-StatesPDCCH-ToReleaseList SEQUENCE(SIZE (1..maxNrofTCI-StatesPDCCH)) OF TCI-StateId OPTIONAL, -- Cond NotSIB1-initialBWP tci-PresentInDCI ENUMERATED {enabled} OPTIONAL, -- Need S pdcch-DMRS-ScramblingID INTEGER (0..65535) OPTIONAL, -- Need S}

[0119] CORESET는 주파수 영역에서 RB들로 구성될 수 있고, 시간 영역에서 ∈{1,2,3} symbols. The PDCCH may be composed of one or more CCEs (Control Channel Elements). One CCE may be composed of six REGs (Resource Element Groups), and a REG may be defined as one RB during one OFDM symbol. Within one CORESET, REGs may be indexed in time-first order, starting with REG index 0 from the first OFDM symbol of the CORESET, the lowest RB.

[0120] Interleaved and non-interleaved transmission methods for PDCCH can be supported. The base station can configure whether to use interleaved or non-interleaved transmission for each CORESET to the terminal through upper layer signaling. Interleaving can be performed in units of REG bundles. A REG bundle can be defined as a set of one or more REGs. The terminal can determine the CCE-to-REG mapping method in the corresponding CORESET based on whether to use interleaved or non-interleaved transmission as configured by the base station, as shown in below.

[0121]

[0122] The base station can inform the terminal of configuration information such as which symbol within the slot the PDCCH is mapped to and the transmission cycle through signaling.

[0123] The search space of the PDCCH is described as follows. The number of CCEs required to transmit the PDCCH can be 1, 2, 4, 8, or 16 depending on the aggregation level (AL), and different numbers of CCEs can be used for link adaptation of the downlink control channel. For example, when AL=L, a single downlink control channel can be transmitted through L CCEs. The UE performs blind decoding, which detects a signal without knowing information about the downlink control channel, and for this purpose, a search space representing a set of CCEs can be defined. The search space is a set of downlink control channel candidates consisting of CCEs that the UE should attempt to decode at a given aggregation level. Since there are various aggregation levels that create a single group with 1, 2, 4, 8, or 16 CCEs, the UE can have multiple search spaces. A search space set can be defined as the set of search spaces at all established aggregation levels.

[0124] Search spaces can be classified into a common search space (CSS) and a UE-specific search space (USS). A certain group of UEs or all UEs can monitor the common search space of the PDCCH to receive cell-common control information, such as dynamic scheduling for the System Information Block (SIB) or paging messages. For example, a UE can 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 UEs or all UEs must receive the PDCCH, it can be defined as a set of pre-arranged CCEs. UE-specific scheduling allocation information for the PDSCH or PUSCH can be received by the UE by monitoring the UE-specific search space of the PDCCH. The UE-specific search space can be defined UE-specifically as a function of the UE's identity (ID) and various system parameters.

[0125] The base station can set the search space configuration information of the PDCCH to the terminal through higher layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station can set the number of PDCCH candidates in each aggregation level L, the monitoring period for the search space, the monitoring occasion for each symbol in the slot for the search space, the search space type (common search space or terminal-specific search space), the combination of the DCI format and RNTI to be monitored in the corresponding search space, the CORESET index to be monitored for the search space, etc. to the terminal. For example, the parameters for the search space for the PDCCH may include information such as the following .

[0126] SearchSpace ::= SEQUENCE { searchSpaceId SearchSpaceId, controlResourceSetId ControlResourceSetId OPTIONAL, -- Cond SetupOnly monitoringSlotPeriodicityAndOffset CHOICE { sl1 NULL, sl2 INTEGER (0..1), sl4 INTEGER (0..3), sl5 INTEGER (0..4), sl8 INTEGER (0..7), sl10 INTEGER (0..9), sl16 INTEGER (0..15), sl20 INTEGER (0..19), sl40 INTEGER (0..39), sl80 INTEGER (0..79), sl160 INTEGER (0..159), sl320 INTEGER (0..319), sl640 INTEGER (0..639), sl1280 INTEGER (0..1279), sl2560 INTEGER (0..2559) } OPTIONAL, -- Cond Setup duration INTEGER (2..2559) OPTIONAL, -- Need R monitoringSymbolsWithinSlot BIT STRING (SIZE (14)) OPTIONAL, -- Cond Setup nrofCandidates SEQUENCE { aggregationLevel1 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8}, aggregationLevel2 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8}, aggregationLevel4 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8}, aggregationLevel8 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8}, aggregationLevel16 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8} } OPTIONAL, -- Cond Setup searchSpaceType CHOICE { common SEQUENCE { dci-Format0-0-AndFormat1-0 SEQUENCE { ...} OPTIONAL, -- Need R dci-Format2-0 SEQUENCE { nrofCandidates-SFI SEQUENCE { aggregationLevel1 ENUMERATED {n1, n2} OPTIONAL, -- Need R aggregationLevel2 ENUMERATED {n1, n2} OPTIONAL, -- Need R aggregationLevel4 ENUMERATED {n1, n2} OPTIONAL, -- Need R aggregationLevel8 ENUMERATED {n1, n2} OPTIONAL, -- Need R aggregationLevel16 ENUMERATED {n1, n2} OPTIONAL -- Need R }, ... } OPTIONAL, -- Need R dci-Format2-1 SEQUENCE { ... } OPTIONAL, -- Need R dci-Format2-2 SEQUENCE { ... } OPTIONAL, -- Need R dci-Format2-3 SEQUENCE { dummy1 ENUMERATED {sl1, sl2, sl4, sl5, sl8, sl10, sl16, sl20} OPTIONAL, -- Cond Setup dummy2 ENUMERATED {n1, n2}, ... } OPTIONAL -- Need R }, ue-Specific SEQUENCE { dci-Formats ENUMERATED {formats0-0-And-1-0, formats0-1-And-1-1}, ..., } } OPTIONAL -- Cond Setup2}.

[0127] Depending on the configuration information, the base station may configure one or more search space sets for the terminal. In some embodiments, the base station may configure search space set 1 and search space set 2 for the terminal. In search space set 1, the terminal may be configured to monitor DCI format A scrambled with X-RNTI in a common search space, and in search space set 2, the terminal may be configured to monitor DCI format B scrambled with Y-RNTI in a terminal-specific search space.

[0128] According to the configuration information, one or more search space sets may exist in a common search space or a terminal-specific search space. 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 terminal-specific search spaces.

[0129] In a common search space, a terminal can monitor the following combinations of DCI formats and RNTIs, although these are not limited to the following examples.

[0130] - 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

[0131] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0132] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0133] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0134] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0135] In a terminal-specific search space, a terminal can monitor the following combinations of DCI formats and RNTIs, although these are not limited to the following examples.

[0136] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0137] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0138] RNTIs may follow the following definitions and uses:

[0139] C-RNTI (Cell RNTI): For terminal-specific PDSCH or PUSCH scheduling purposes.

[0140] TC-RNTI (Temporary Cell RNTI): For terminal-specific PDSCH scheduling purposes

[0141] CS-RNTI (Configured Scheduling RNTI): Used for semi-static terminal-specific PDSCH scheduling.

[0142] RA-RNTI (Random Access RNTI): Used for PDSCH scheduling in the random access phase.

[0143] P-RNTI (Paging RNTI): Used for scheduling PDSCH where paging is transmitted.

[0144] SI-RNTI (System Information RNTI): Used for scheduling PDSCH where system information is transmitted.

[0145] INT-RNTI (Interruption RNTI): Used to indicate whether PDSCH is punctured.

[0146] TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to indicate power control commands for PUSCH.

[0147] TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to indicate power control commands for PUCCH.

[0148] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to indicate power control commands for SRS.

[0149] The DCI formats described above can follow the definitions shown in below.

[0150] DCI formatUsage0_0Scheduling of PUSCH in one cell0_1Scheduling of PUSCH in one cell1_0Scheduling of PDSCH in one cell1_1Scheduling of PDSCH in one cell2_0Notifying a group of UEs of the slot format2_1Notifying a group of UEs of the PRB(s) and OFDM symbol(s) where UE may assume no transmission is intended for the UE2_2Transmission of TPC commands for PUCCH and PUSCH2_3Transmission of a group of TPC commands for SRS transmissions by one or more UEs

[0151] CORESET p, the search space of aggregation level L in the search space set s can be expressed as the following mathematical formula.

[0152] [Mathematical Formula 1]

[0153]

[0154] - L: Integration level

[0155] - n CI : Carrier Index

[0156] - N CCE,p : Total number of CCEs existing within the control resource set p

[0157] - n μ s,f : slot index

[0158] - M (L) p,s,max : Number of PDCCH candidates for aggregation level L

[0159] - m snCI = 0, ..., M (L) p,s,max -1: PDCCH candidate index of aggregation level L

[0160] - i = 0, ..., L-1

[0161] - , , , , ,

[0162] - n RNTI : Terminal identifier

[0163] The value can be 0 for a common search space.

[0164] In the case of a terminal-specific search space, the value may correspond to a value that changes according to the terminal's ID (C-RNTI or ID set to the terminal by the base station) and time index.

[0165] Below, we will specifically describe how a terminal measures channel conditions and reports them to a base station in a 5G communication system.

[0166] Channel state information (CSI) may include the following information:

[0167] - Channel Quality Indicator (CQI): CQI index indication information consisting of a modulation method and coding rate that satisfies the minimum reception error rate of a predefined PDSCH.

[0168] - Precoding Matrix Indicator (PMI): Precoding matrix indicator information selected by the terminal.

[0169] - CRI (CSI-RS resource indicator): CSI-RS information measured by the terminal

[0170] - RI (Rank Indicator): Rank indication information selected by the terminal

[0171] - LI (Layer indicator): Indication information for the best layer among the precoding matrices reported by the terminal.

[0172] - SSBRI (SS / PBCH block resource indicator): SSB information measured by the terminal

[0173] - L1-RSRP (Reference Signal Received Power): L1 RSRP information measured by the terminal

[0174] The base station can control time and frequency resources for the aforementioned CSI measurement and reporting of the terminal.

[0175] For CSI measurement and reporting operations, 'Aperiodic', 'Semi-Persistent', and 'Periodic' methods are supported, and the base station can set which method to use to the terminal through signaling. The semi-persistent CSI reporting method supports 'Semi-PersistentOnPUCCH' and 'Semi-PersistentOnPUSCH'. In the case of periodic or semi-persistent CSI reporting methods, the terminal can receive PUCCH or PUSCH resources to transmit CSI from the base station through upper layer signaling. The period and slot offset of the PUCCH or PUSCH resources to transmit CSI can be given by setting the subcarrier spacing of the uplink (UL) bandwidth part where the CSI report is set to be transmitted. In the case of the aperiodic CSI reporting method, the terminal can schedule PUSCH resources for transmitting CSI from the base station through L1 signaling (DCI format 0_1 ​​described above).

[0176] Aperiodic CSI reporting of a terminal can use PUSCH, periodic CSI reporting can use PUCCH, and semi-persistent CSI reporting can be performed using PUSCH when triggered or activated by DCI, or PUCCH after being activated by MAC control element (MAC CE).

[0177] Aperiodic CSI reporting may be triggered by the “CSI request” field of the aforementioned DCI format 0_1 ​​corresponding to the scheduling DCI for PUSCH.

[0178] As another way to support ultra-high-speed data services, 5G systems can support ultra-wide bandwidth signal transmission and reception of tens to hundreds of MHz, or even several GHz. The ultra-wide bandwidth signal transmission and reception can be supported through a single component carrier (CC), or through carrier aggregation (CA) technology that combines multiple component carriers. When a mobile communication service provider cannot secure a frequency with sufficient bandwidth to provide ultra-high-speed data services through a single component carrier, carrier aggregation technology can increase the total frequency bandwidth by combining individual component carriers with relatively small bandwidths, thereby enabling ultra-high-speed data services.

[0179] As mentioned above, the frequency band utilized by 5G systems is wide, ranging from hundreds of MHz to tens of GHz.

[0180] FIG. 5 illustrates the interrelationship between frequency bands, coverage, and bandwidth according to one embodiment of the present disclosure.

[0181] Referring to Figure 5, frequency bands of low band (501), mid band (502), high band (503), and ultra high band (504) are illustrated. In general, the lower the frequency band, the greater the coverage due to relatively small path loss, and the higher the frequency band, the smaller the coverage due to relatively high path loss. In the low frequency band, the frequencies that can be used for mobile communication are fragmented, resulting in a small bandwidth, whereas in the high frequency band, it is relatively easy to secure a wide bandwidth frequency, making it 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 the 5G mobile communication system, the 7 to 15 GHz band, called the upper midband, is being considered as one of the candidate frequencies. Typically, mobile communication operators secure multiple frequency bands to provide mobile communication services to users. For example, mobile communication operators can combine existing LTE system frequency bands with newly secured 5G system frequency bands to operate a combined LTE and 5G system. As another example, mobile communication operators can secure frequency bands for 5G systems across multiple bands and then provide mobile communication services through 5G carrier aggregation (CA). Similarly, 6G mobile communication systems can combine 6G frequencies with existing 4G or 5G frequencies, or combine 6G frequencies to provide mobile communication services through 6G CA.

[0182] As described above, since characteristics such as coverage and bandwidth vary depending on the frequency band, mobile communication services that combine multiple frequency bands are becoming more active than mobile communication services that rely on a single frequency band.

[0183] The operation of the system proposed in the present disclosure is described below through specific examples.

[0184] The main point of the present invention is to define operations related to a terminal and a base station that enable a mobile communication service combining multiple frequency bands to be applied to a random access procedure of the terminal.

[0185] The main points of the present invention will be described below with reference to FIGS. 6 and 7.

[0186] FIG. 6 is a diagram illustrating an example of the correlation between downlink frequencies and uplink frequencies in the initial access and random access procedure stages of a terminal. According to FIG. 6, one downlink frequency (601) is connected to one uplink frequency (611), and the connection relationship between the downlink frequency and the uplink frequency is 1:1. Here, the downlink frequency (601) can be used interchangeably with the 'downlink frequency band', and the uplink frequency (611) can be used interchangeably with the 'uplink frequency band'. For example, the terminal in the initial access stage can obtain SSB and system information through the downlink frequency (601) during the cell search process. In addition, when the terminal performs a random access procedure, the terminal can perform uplink transmission in the random access procedure through the uplink frequency (611) connected to the downlink frequency (601), and can perform downlink reception in the random access procedure through the downlink frequency (601). Uplink transmission in a random access procedure may include, for example, transmission of a random access preamble or Message 3 in the case of a 4-Step random access, or transmission of Message A in the case of a 2-Step random access. Downlink reception in a random access procedure may include, for example, reception of a random access response (or Message 2) or Message 4 in the case of a 4-Step random access, or reception of Message B in the case of a 2-Step random access. The base station may provide control information regarding an uplink frequency to the terminal through the system information. In the case of an FDD system, the downlink frequency and the uplink frequency may be physically different frequencies. In the case of a TDD system, the downlink frequency and the uplink frequency may be physically the same frequency.

[0187] FIG. 7 is a diagram illustrating an example in which a 'processing unit' (720) including a plurality of downlink frequencies and a plurality of uplink frequencies is configured according to an embodiment of the present disclosure, and an initial connection and random access procedure of a terminal are performed within the 'processing unit'. FIG. 7 illustrates a processing unit configured with two downlink frequencies and two uplink frequencies. However, such a processing unit is only an example, and the processing unit may be configured with one or more downlink frequencies and one or more uplink frequencies. FIG. 7 basically illustrates an example in which one downlink frequency and one uplink frequency are connected. Accordingly, downlink frequency 1 (701) is connected to uplink frequency 1 (711), and downlink frequency 2 (702) is connected to uplink frequency 2 (712). In addition, each downlink frequency may be connected to the remaining uplink frequencies within the 'processing unit' in addition to the connected uplink frequencies. Accordingly, downlink frequency 1 (701) can be connected to uplink frequency 1 (711) and uplink frequency 2 (712), and downlink frequency 2 (702) can be connected to uplink frequency 1 (711) and uplink frequency 2 (712). The example of Fig. 7 shows that two uplink frequencies are connected to one downlink frequency, and the connection relationship between the downlink frequencies and the uplink frequencies is 1:2. The connection relationship between the downlink frequencies and the uplink frequencies can be generalized as A:B (A≥1, B≥1). Alternatively, two downlink frequencies can be connected to one uplink frequency, and the connection relationship between the uplink frequencies and the downlink frequencies can be represented as 1:2. The connection relationship between the uplink frequencies and the downlink frequencies can be generalized as C:D (C≥1, D≥1).In this specification, the existence of a connection relationship between an uplink frequency and a downlink frequency means that a terminal and a base station can transmit and receive channels and signals (for random access) using the uplink frequency and the downlink frequency with which the connection relationship exists. For example, when one downlink frequency is connected to multiple uplink frequencies, a terminal and a base station can transmit and receive channels and signals (for random access) using the one downlink frequency and one of the multiple uplink frequencies. The connection relationship can be confirmed by the connection between the uplink frequency and the downlink frequency illustrated in FIG. 7.

[0188] The above downlink frequency or uplink frequency may exist in different frequency bands of FIG. 5 or may exist in the same frequency band. For example, downlink frequency 1 may exist in the low band (501) and downlink frequency 2 may exist in the mid band (502), or both downlink frequencies 1 and 2 may exist in the mid band (502). In addition, it is possible that corresponding downlink frequencies and uplink frequencies exist in different frequency bands of FIG. 5 or may exist in the same frequency band. For example, downlink frequency 1 may exist in the low band (501) and uplink frequency 1 may exist in the mid band (502), or both downlink frequency 1 and uplink frequency 1 may exist in the mid band (502).

[0189] In the example of Fig. 7, when the terminal acquires SSB and system information through downlink frequency 1 (701), the terminal can proceed with the random access procedure in the following manner.

[0190] - Random Access Method 1-1: The terminal can perform uplink transmission according to a random access procedure through the uplink frequency 1 (711) connected to the downlink frequency 1 (701), and can perform downlink reception according to a random access procedure through the downlink frequency 1 (701). Uplink transmission according to a random access procedure may include, for example, transmission of a random access preamble or Message 3 in the case of 4-Step random access, or transmission of Message A in the case of 2-Step random access. Downlink reception according to a random access procedure may include, for example, reception of a random access response (or Message 2) or Message 4 in the case of 4-Step random access, or reception of Message B in the case of 2-Step random access. The base station can provide frequency-related control information, such as a frequency domain location, bandwidth, and subcarrier spacing for the uplink frequency 1 (711), to the terminal through system information transmitted on the downlink frequency 1 (701).

[0191] - Random Access Method 1-2: The terminal can perform uplink transmission according to the random access procedure through the uplink frequency 2 (712), which is the remaining uplink frequency constituting the 'processing unit', and can perform downlink reception according to the random access procedure through the downlink frequency 1 (701). Uplink transmission according to the random access procedure may include, for example, transmission of a random access preamble or Message 3 in the case of 4-Step random access, or transmission of Message A in the case of 2-Step random access. Downlink reception according to the random access procedure may include, for example, reception of a random access response (or Message 2) or Message 4 in the case of 4-Step random access, or reception of Message B in the case of 2-Step random access. The base station can provide frequency-related control information, such as a frequency domain location, bandwidth, and subcarrier spacing for the uplink frequency 2 (712), to the terminal through system information transmitted on the downlink frequency 1 (701).

[0192] If the terminal acquires SSB and system information through downlink frequency 2 (702), the terminal can proceed with the random access procedure in the following manner.

[0193] - Random Access Method 2-1: The terminal can perform uplink transmission according to a random access procedure through the uplink frequency 2 (712) connected to the downlink frequency 2 (702), and can perform downlink reception according to the random access procedure through the downlink frequency 2 (702). Uplink transmission according to the random access procedure may include, for example, transmission of a random access preamble or Message 3 in the case of 4-Step random access, or transmission of Message A in the case of 2-Step random access. Downlink reception according to the random access procedure may include, for example, reception of a random access response (or Message 2) or Message 4 in the case of 4-Step random access, or reception of Message B in the case of 2-Step random access. The base station can provide frequency-related control information, such as a frequency domain location, bandwidth, and subcarrier spacing for the uplink frequency 2 (712), to the terminal through system information transmitted on the downlink frequency 2 (702).

[0194] - Random Access Method 2-2: The terminal can perform uplink transmission according to the random access procedure through the uplink frequency 1 (711), which is the remaining uplink frequency constituting the 'processing unit', and can perform downlink reception according to the random access procedure through the downlink frequency 2 (702). Uplink transmission according to the random access procedure may include, for example, transmission of a random access preamble or Message 3 in the case of 4-Step random access, or transmission of Message A in the case of 2-Step random access. Downlink reception according to the random access procedure may include, for example, reception of a random access response (or Message 2) or Message 4 in the case of 4-Step random access, or reception of Message B in the case of 2-Step random access. The base station can provide frequency-related control information, such as a frequency domain location, bandwidth, and subcarrier spacing for the uplink frequency 1 (711), to the terminal through system information (System Information Block, SIB) transmitted on the downlink frequency 2 (702).

[0195] According to the above, the terminal can synchronize downlink time and frequency based on the SSB received on downlink frequency 1 or downlink frequency 2, and obtain a cell identifier (cell ID). The terminal can receive the PBCH using the obtained cell ID, and obtain the MIB (Master Information Block), which is essential system information, from the PBCH. The MIB includes CORESET information, which is a time-frequency resource to which the PDCCH is mapped. Accordingly, the terminal can monitor the PDCCH that schedules the PDSCH for SIB transmission in the CORESET. The terminal can receive the PDSCH for SIB transmission from the scheduling information of the PDCCH and obtain the SIB. The SIB includes control information related to transmission and reception common to the cell, and may include, for example, random access-related control information, paging-related control information, and common control information for various physical channels.

[0196] The base station can provide the terminal with frequency-related control information of uplink frequency 1 and uplink frequency 2, which constitute the 'processing unit', through system information transmitted on downlink frequency 1. Alternatively, the base station can provide the terminal with frequency-related control information of uplink frequency 1 and uplink frequency 2, which constitute the 'processing unit', through system information transmitted on downlink frequency 2.

[0197] The base station may stop (OFF) or maintain (ON) part or all of the transmission and reception operations through the downlink frequency or uplink frequency within the 'processing unit' as needed. The base station may notify the terminal through signaling whether the OFF operation or the ON operation is applied to each of the downlink frequency and the uplink frequency. For example, the base station may notify the terminal through upper layer signaling that the downlink frequency 2 and the uplink frequency 2 are OFF or deactivated. The base station may expect the effect of reducing base station power consumption through the OFF operation.

[0198] The base station may transmit a frequency indicator to the terminal, indicating the uplink frequency to be used for uplink transmission in the random access procedure, through the System Information Block (SIB) or PDCCH or SSB transmitted on each of the downlink frequency 1 (701) and downlink frequency 2 (702). For example, the base station may signal the frequency indicator to the terminal through the following downlink signal or downlink channel.

[0199] - PSS or SSS: The base station may transmit the frequency indicator by configuring it with control information included in the PSS or SSS. Alternatively, the frequency indicator may be included in a physical signal for time and frequency synchronization of a terminal transmitted by the base station.

[0200] - PBCH MIB: The base station can transmit the above frequency indicator as control information of the MIB included in the PBCH.

[0201] - PBCH payload: The base station can transmit the above frequency indicator as control information of the PBCH payload included in the PBCH.

[0202] - PBCH DMRS: The base station can transmit the above frequency indicator by configuring it with control information included in the DMRS for PBCH.

[0203] - SIB PDSCH (For convenience of explanation, a PDSCH that includes SIB as control information is referred to as SIB PDSCH): The base station can configure the above frequency indicator with control information included in the SIB and transmit it through the SIB PDSCH.

[0204] - SIB PDCCH (For convenience of explanation, the PDCCH that schedules the SIB PDSCH is referred to as SIB PDCCH): The base station can transmit the above frequency indicator by configuring it as control information of the SIB PDCCH.

[0205] For example, the base station can configure the frequency indicator with 1 bit of control information. If the 1 bit of control information constituting the frequency indicator is '0', the frequency indicator can instruct the terminal to transmit an uplink signal through uplink frequency 1, and if the 1 bit of control information constituting the frequency indicator is '1', the frequency indicator can instruct the terminal to transmit an uplink signal through uplink frequency 2. The frequency indicator can be generalized to represent the frequency indicator with N bits according to the number of frequencies constituting the 'processing unit'. The bit size of the frequency indicator can be fixed to a pre-agreed value, or the bit size of the frequency indicator can be notified by additional control information of the MIB. Alternatively, N bits can be based on the number of frequencies to be indicated, and for example, if X is the number of frequencies to be indicated, it can be determined as ceil(log2X). The above frequency indicator may be included not only in the SIB PDCCH, but also in the PDCCH scheduling a paging message, the PDCCH required for a random access procedure, and the PDCCH scheduling terminal-specific data after the terminal is in a connected state. That is, the above frequency indicator may be included in the PDCCH scrambled with SI-RNTI, P-RNTI, RA-RNTI, TC-RNTI, C-RNTI, etc.

[0206] Although the names of the 5G system are used to describe the embodiments of the present disclosure, the names of SSB, SIB PDCCH, SIB PDSCH, etc. described above are merely examples and can be understood as messages that include information of the same content as described above or perform the same role.

[0207] The terminal should be able to minimize transmission delay by quickly changing the uplink frequency according to the instruction of the frequency indicator. Therefore, the terminal needs to have a quick frequency change operation as a basic function of the terminal. Alternatively, in order to establish a quick frequency change operation of the terminal, the frequency change operation of the terminal according to the frequency indicator can be limited to be completed within at least X time units. At this time, the time unit can be a symbol, a slot, ms, etc. For example, the X time unit can start from a specific symbol of a TTI in which control information including a frequency indicator is received on a physical downlink control channel, or from a specific symbol of a TTI in which reception confirmation information for the physical downlink data channel is transmitted, in case the frequency indicator is received on a physical downlink data channel. The X value can be fixed to a predetermined value or can be set by a base station.

[0208] Hereinafter, a description of each specific embodiment is provided. The present invention may include multiple embodiments, and each embodiment may be implemented independently, but as long as they are not mutually exclusive, the multiple embodiments may be implemented in combination with each other. Such combinations encompass various modifications and variations of the present invention, and may be implemented in various ways depending on technical needs or application environments. Even if the multiple embodiments use different approaches to achieve the purpose of the invention, as long as the embodiments of the present invention are not technically mutually exclusive, they may be used simultaneously or complementarily. Such combinations may be modified in various ways depending on technical requirements or specific application cases, and the present invention may encompass various embodiments that include such modifications and combinations.

[0209] <First embodiment>

[0210] The first embodiment describes a method for determining a random access preamble transmission power of a terminal when applying a mobile communication service combining multiple frequency bands to a random access procedure of a terminal.

[0211] Terminal's random access preamble transmission power (P PRACH ) can be determined as in the following <Mathematical Formula 2>, which is expressed in dBm units. When a terminal supports multiple cells, the transmission power (P) of the terminal's random access preamble PRACH ) can be determined for each cell (c is the cell index). <Mathematical expression 2> represents the transmission power at transmission occasion i, which is the time unit in which the random access preamble is transmitted.

[0212] [Equation 2]

[0213]

[0214] 1) P CMAX,c : The maximum transmission power allowed to the terminal, determined by the terminal by referring to the terminal's power class and upper layer signaling settings. If the terminal supports multiple cells, P CMAX,c can be determined individually for each cell.

[0215] 2) : The random access preamble reception power required for the base station to receive the random access preamble is provided from the upper layer as the PREAMBLE_RECEIVED_TARGET_POWER value, and this can be calculated by the following <Mathematical Formula 3>. If the terminal supports multiple cells, can be determined individually for each cell.

[0216] [Equation 3]

[0217] PREAMBLE_RECEIVED_TARGET_POWER = preambleReceivedTargetPower + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER - 1)×PREAMBLE_POWER_RAMPING_STEP

[0218] 2-1) preambleReceivedTargetPower: This is the initial value of the random access preamble reception power required by the base station to receive the random access preamble, and is included in the system information and signaled to the terminal.

[0219] 2-2)DELTA_PREAMBLE: This is an offset value to adjust additional transmission power for each random access preamble format.

[0220] 2-3)PREAMBLE_POWER_RAMPING_COUNTER: A counter that indicates the number of times the random access preamble is powered up during the random access procedure. The initial value is 1. If the terminal does not receive a random access response (RAR, message 2) from the base station for a predetermined period of time after transmitting the random access preamble, the terminal determines that the base station has failed to receive the random access preamble, retransmits the random access preamble, and increases the counter by 1. In general, PREAMBLE_POWER_RAMPING_COUNTER can be used interchangeably with PREAMBLE_TRANSMISSION_COUNTER. PREAMBLE_TRANSMISSION_COUNTER is a counter that indicates the number of times the random access preamble is transmitted, and the initial value is 1.

[0221] 2-4) PREAMBLE_POWER_RAMPING_STEP: When the terminal retransmits a random access preamble to the base station, the transmission power of the random access preamble is increased by PREAMBLE_POWER_RAMPING_STEP (power ramping) and transmitted to the base station. The value of PREAMBLE_POWER_RAMPING_STEP can be a pre-agreed value or can be set by the base station and notified to the terminal through signaling.

[0222] 3) PL c : It is an indicator of the good or bad channel environment as path loss (PL) between the base station and the terminal. The larger the path loss value, the worse the channel environment is, and it has the characteristic of having small changes over time. The larger the path loss, the more the terminal must transmit the signal it wants to transmit by setting the transmission power to be relatively large to overcome the bad channel environment. If the terminal supports multiple cells, PL c can be determined individually for each cell.

[0223] The terminal can measure the received signal strength of the reference signal (RS) transmitted by the base station and calculate the path loss according to the following <Mathematical Formula 4>. The reference signal can be SSB or CSI-RS, and the base station can designate and inform the terminal which signal among the SSB or CSI-RS to use as the reference signal. Alternatively, if there is no separate setting, the terminal can determine SSB as the reference signal.

[0224] [Equation 4]

[0225] PL = referenceSignalPower - RSRP

[0226] In the above <Mathematical Formula 4>, 'referenceSignalPower' represents the base station transmission power of the RS that the base station notifies the terminal through signaling, and 'RSRP (Reference Signal Received Power)' represents the reception signal strength of the RS measured by the terminal that received the RS.

[0227] In the first embodiment, when applying the above-described 'processing unit'-based random access operation, the following method can be applied to determine the reference signal and the transmission power of the random access preamble that the terminal refers to for pathloss calculation. In the following description, it is assumed that the 'processing unit' is composed of two downlink frequencies and two uplink frequencies, but this is only an example for description and does not limit the scope of the present invention. The description below can generally be applied to a case where the 'processing unit' is composed of N downlink frequencies and M uplink frequencies. For each downlink frequency and uplink frequency, the base station provides some or all of the following control information to the terminal.

[0228] - Downlink control information:

[0229] ■ ReferenceSignalPower of the reference signal transmitted at the corresponding downlink frequency

[0230] - Uplink control information:

[0231] ■ Random access configuration identifier (rachConfigID) that distinguishes random access configuration

[0232] ■ preambleReceivedTargetPower indicates the target reception power of the random access preamble transmitted on the corresponding uplink frequency.

[0233] ■ Power offset (powerOffset) to further supplement the transmission power of the terminal. powerOffset can be determined based on the frequency domain interval between the downlink frequency at which the reference signal, which is the target of pathloss measurement of the terminal, is transmitted and the uplink frequency at which the random access preamble is transmitted. By applying powerOffset, the above <Mathematical Formula 2> can be converted to <Mathematical Formula 5> below.

[0234] [Equation 5]

[0235]

[0236] The above control information may be included in the system information transmitted on each downlink frequency. The terminal may measure a reference signal transmitted on a downlink frequency constituting the 'processing unit', and if the reception strength is above a predetermined threshold, the reference signal of the corresponding downlink frequency may be determined as a reference signal for calculating the terminal's pathloss. The threshold may be a pre-agreed value, or the base station may notify the terminal through upper layer signaling.

[0237] - Random access preamble transmission power determination method 1: The base station can inform the terminal of which setting among the control information provided as the system information is to be explicitly applied to calculate the random access preamble transmission power. FIG. 8 is a diagram illustrating an example of linking a downlink frequency and an uplink frequency according to the random access preamble transmission power determination method 1 according to an embodiment of the present disclosure. Referring to FIG. 8, the base station can inform the terminal of the connection relationship between the downlink control information and the uplink control information through the random access configuration identifier (rachConfigID, 821). Accordingly, the base station can adjust the connection relationship between the downlink control information and the uplink control information, if necessary. The random access configuration identifier can be included as control information of the SIB PDCCH and signaled by the base station to the terminal. For example, the base station can designate the random access configuration identifier as '0' as uplink control information of uplink frequency 1 (811) and designate the random access configuration identifier as '1' as uplink control information of uplink frequency 2 (812). If the terminal determines that the received signal strength of the reference signal received on downlink frequency 1 (801) or downlink frequency 2 (802) is higher than a predetermined threshold value, the terminal determines the reference signal of downlink frequency 1 (801) or downlink frequency 2 (802) as a reference signal to be used for pathloss calculation. If the base station indicates a random access configuration identifier = '0' through SIB PDCCH, the terminal can calculate the transmission power of the random access preamble by referring to preambleReceivedTargetPower and powerOffset included in the uplink control information in which the random access configuration identifier is designated as '0'. The random access configuration identifier can be replaced with the above-described frequency indicator.

[0238] - Random access preamble transmission power determination method 2: As a modification of the random access preamble transmission power determination method 1, the base station can inform the terminal of the connection relationship between downlink control information and uplink control information by explicitly signaling a random access configuration identifier (rachConfigID) and a powerOffset value. FIG. 9 is a diagram illustrating an example of linking a downlink frequency and an uplink frequency according to the random access preamble transmission power determination method 2 according to an embodiment of the present disclosure. Referring to FIG. 9, the base station can explicitly signal (921) a random access configuration identifier (rachConfigID) and a powerOffset value. The signaling can be configured to be included as control information of an SIB PDCCH. For example, the base station can designate the random access configuration identifier as '0' as uplink control information of uplink frequency 1 (911) and designate the random access configuration identifier as '1' as uplink control information of uplink frequency 2 (912). If the terminal determines that the received signal strength of the reference signal received on downlink frequency 1 (901) or downlink frequency 2 (902) is higher than a predetermined threshold, the terminal determines the reference signal of downlink frequency 1 (901) or downlink frequency 2 (902) as a reference signal to be referred to for pathloss calculation. If the base station indicates a random access configuration identifier = '0' through SIB PDCCH, the terminal can calculate the transmission power of the random access preamble by referring to the preambleReceivedTargetPower included in the uplink control information in which the random access configuration identifier is designated as '0' and the powerOffset indicated through the control information of SIB PDCCH. The random access configuration identifier can be replaced with the above-described frequency indicator.The base station may set a candidate group of powerOffset values ​​by including them in the uplink control information, and may indicate one of the candidate groups of powerOffset values ​​through the powerOffset indicator of the SIB PDCCH, or may directly inform the terminal of the powerOffset value through the powerOffset indicator of the SIB PDCCH without including a separate candidate group of powerOffset values ​​in the uplink control information.

[0239] - Random access preamble transmission power determination method 3: Unlike the random access preamble transmission power determination method 1 or 2, the base station can specifically inform the terminal of the connection relationship between the downlink control information and the uplink control information when providing system information to the terminal. FIG. 10 is a diagram showing an example of connecting a downlink frequency and an uplink frequency according to the random access preamble transmission power determination method 3 according to an embodiment of the present disclosure. Referring to FIG. 10, downlink control information for downlink frequency 1 (1001) can be connected with uplink control information for uplink frequency 1 (1011), and downlink control information for downlink frequency 2 (1002) can be connected with uplink control information for uplink frequency 2 (1012). In this case, no additional signaling via SIB PDCCH is required to indicate the connection relationship between downlink control information and uplink control information, whereas complex steps may be required to change the connection relationship between downlink control information and uplink control information.

[0240] - Random Access Preamble Transmission Power Determination Method 4: As a modification of the random access preamble transmission power determination method 3, when providing system information to a terminal, the base station may signal a multi-connection relationship between the downlink control information and the uplink control information, and allow the terminal to finally determine the connection relationship between specific downlink control information and specific uplink control information. FIG. 11 is a diagram illustrating an example of connecting a downlink frequency and an uplink frequency according to the random access preamble transmission power determination method 4 according to an embodiment of the present disclosure. Referring to FIG. 11, downlink control information for downlink frequency 1 (1101) may be multi-connected with uplink control information for uplink frequency 1 (1111) and uplink control information for uplink frequency 2 (1112), and downlink control information for downlink frequency 2 (1102) may be multi-connected with uplink control information for uplink frequency 2 (1112) and uplink control information for uplink frequency 1 (1111). The base station may include the multi-connection relationship between the downlink control information and the uplink control information in system information and notify the terminal. If the terminal determines that the received signal strength of the reference signal received at downlink frequency 1 (1101) is greater than or equal to a predetermined threshold value 1, the terminal determines the reference signal of downlink frequency 1 (1101) as a reference signal to be referred to in pathloss calculation. And if it is determined that the reception signal strength of the above reference signal is greater than or equal to a predetermined threshold value 2, the terminal can calculate the transmission power of the random access preamble by referring to the uplink control information (preambleReceivedTargetPower, powerOffset) of uplink frequency 1 (1111).On the other hand, if it is determined that the received signal strength of the above reference signal is less than a predetermined threshold value 2, the terminal can calculate the transmission power of the random access preamble by referring to the uplink control information (preambleReceivedTargetPower, powerOffset) of the uplink frequency 2 (1112). The threshold value 1 or threshold value 2 may be a value agreed upon in advance, or the base station may notify the terminal through upper layer signaling.

[0241] Although the names of the 5G system are used to describe the embodiments of the present disclosure, the names of SSB, MIB, SIB PDCCH, SIB PDSCH, message 1 to 4, etc. described above are merely examples, and it is possible to understand them as messages that include information of the same content as described above or perform the same role.

[0242] <Second embodiment>

[0243] The second embodiment describes a power ramping method as an uplink power control operation of a terminal when applying a mobile communication service combining multiple frequency bands to a random access procedure of a terminal.

[0244] During the random access procedure, if the following cases occur, the terminal performs retransmission of the random access preamble. At this time, the terminal can increase the transmission power of the retransmitted random access preamble by a predetermined step (PREAMBLE_POWER_RAMPING_STEP) compared to the transmission power of the previously transmitted random access preamble and transmit it, thereby increasing the probability of the base station receiving the random access preamble. Increasing the transmission power of the retransmitted random access preamble at this time is called power ramping.

[0245] - Case 1 of random access preamble retransmission: When the terminal transmits a random access preamble and then fails to receive message 2 from the base station within a specified time (T1).

[0246] - Random access preamble retransmission case 2: When the terminal transmits message 3 and then fails to receive message 4 from the base station within a specified time (T2).

[0247] The above PREAMBLE_POWER_RAMPING_STEP, T1, and T2 can apply values ​​agreed upon in advance, or the base station can notify the terminal through signaling.

[0248] Power ramping of the random access preamble can be effective when there is a certain level of correlation (n ≥ 1) between the n-th transmitted random access preamble and the n+1-th transmitted random access preamble. For example, if there is a large change in the channel environment between the n-th transmitted random access preamble and the n+1-th transmitted random access preamble, the correlation between the two random access preambles will decrease. Nevertheless, if the terminal performs power ramping when transmitting the random access preamble, not only will it not help the base station receive the random access preamble, but it may also have the side effect of unnecessarily increasing the terminal's power consumption and increasing uplink interference. Therefore, under the above conditions, it is preferable to temporarily suspend the power ramping for the random access preamble. In the second embodiment, if the terminal satisfies at least one of the following conditions, the power ramping of the random access preamble is temporarily suspended.

[0249] - Random access preamble power ramping pause condition 1: When the uplink frequency changes between the nth transmitted random access preamble and the n+1th transmitted random access preamble.

[0250] - Random access preamble power ramping pause condition 2: When the uplink transmission beam changes between the nth transmitted random access preamble and the n+1th transmitted random access preamble.

[0251] Hereinafter, the operation of the second embodiment will be described with reference to FIG. 12. For the purpose of explanation, it is assumed that the above-described 'processing unit'-based random access operation is applied, and the 'processing unit' is configured with two downlink frequencies (downlink frequency 1, downlink frequency 2) and two uplink frequencies (uplink frequency 1, uplink frequency 2), but this is only an example for explanation and does not limit the scope of the present invention.

[0252] In step 1201, the terminal can transmit a random access preamble. To this end, the terminal can synchronize downlink time and frequency based on SSB received through downlink frequency 1, and acquire system information received through downlink frequency 1. The terminal can determine an uplink frequency for transmitting the random access preamble and the transmission power of the random access preamble according to the method of the first embodiment described above, and transmit the random access preamble. For example, it is assumed that in step 1201, the terminal transmits the random access preamble by applying the transmission power of P1 through uplink frequency 1. At this time, the terminal initializes PREAMBLE_POWER_RAMPING_COUNTER to '1'.

[0253] If at least one of the random access preamble retransmission cases described above is applicable, the terminal can prepare for random access preamble retransmission in step 1202.

[0254] At step 1203, the terminal can determine whether to apply power ramping when retransmitting a random access preamble by referring to the random access preamble power ramping pause condition.

[0255] If the judgment result of step 1203 does not correspond to the random access preamble power ramping pause condition, the terminal increases PREAMBLE_POWER_RAMPING_COUNTER by 1 in step 1204 (PREAMBLE_POWER_RAMPING_COUNTER = 2) and calculates the transmission power of the random access preamble by referring to <Mathematical Formula 2> and / or <Mathematical Formula 3>. Accordingly, the terminal applies the transmission power of the random access preamble to P2 with power ramping and retransmits it to the base station.

[0256] If the determination result of step 1203 corresponds to the random access preamble power ramping pause condition, the terminal calculates the transmission power of the random access preamble in step 1205 while maintaining the PREAMBLE_POWER_RAMPING_COUNTER as it is (PREAMBLE_POWER_RAMPING_COUNTER = 1) without changing it from the previous value. For example, if the terminal transmits the random access preamble that it wants to retransmit through uplink frequency 2, the terminal pauses power ramping because the random access preamble power ramping pause condition 1 is satisfied. Alternatively, if the uplink transmission beam of the random access preamble that the terminal wants to retransmit is changed, the terminal pauses power ramping because the random access preamble power ramping pause condition 2 is satisfied. If power ramping is paused according to step 1205, the terminal retransmits the random access preamble by applying the transmission power of the random access preamble to the previous transmission power value, P1.

[0257] The terminal determination procedure of step 1203 above can be modified in various ways. The modified operation of the second embodiment is described below with reference to FIG. 13.

[0258] In step 1301, the terminal can transmit a random access preamble. To this end, the terminal can synchronize downlink time and frequency based on SSB received through downlink frequency 1, and acquire system information received through downlink frequency 1. The terminal can determine an uplink frequency for transmitting the random access preamble and the transmission power of the random access preamble according to the method of the first embodiment described above, and transmit the random access preamble. For example, it is assumed that in step 1201, the terminal transmits the random access preamble by applying the transmission power of P1 through uplink frequency 1. At this time, the terminal initializes PREAMBLE_POWER_RAMPING_COUNTER to '1'.

[0259] If at least one of the random access preamble retransmission cases described above applies, the terminal can prepare for random access preamble retransmission in step 1302.

[0260] In step 1303, the terminal determines whether to proceed to the next step by referring to the following various conditions for random access preamble retransmission.

[0261] - Random access preamble power ramping pause condition: At least one of the following conditions described in the second embodiment may be present.

[0262] ■ Random access preamble power ramping pause condition 1: When the uplink frequency changes between the nth transmitted random access preamble and the n+1th transmitted random access preamble.

[0263] ■ Random access preamble power ramping pause condition 2: When the uplink transmission beam changes between the nth transmitted random access preamble and the n+1th transmitted random access preamble.

[0264] - Uplink transmission power reduction condition: If the transmission of another uplink channel or uplink signal overlaps with the time when the terminal intends to transmit the random access preamble, the terminal adjusts the transmission power of the uplink channel or uplink signal to be transmitted or stops transmission according to the priority. If the terminal transmits two or more uplink channels or uplink signals simultaneously, the transmission power of each may be reduced within the limit that the sum of the transmission powers does not exceed the maximum transmission power allowed to the terminal to perform simultaneous transmission. When the reduced transmission power becomes '0', the terminal stops transmitting the corresponding uplink channel or uplink signal.

[0265] If the terminal determines to normally retransmit the random access preamble based on the above conditions, in step 1304, the terminal may calculate the transmission power of the random access preamble by increasing the PREAMBLE_POWER_RAMPING_COUNTER by 1 from the previous value and perform retransmission of the random access preamble. For example, if the random access preamble power ramping pause condition is not met and the uplink transmission power reduction condition is not met, the terminal may determine to normally retransmit the random access preamble.

[0266] If the terminal determines, based on the above conditions, to retransmit the random access preamble but to stop power ramping of the random access preamble, then in step 1305, the terminal may maintain the PREAMBLE_POWER_RAMPING_COUNTER value unchanged from the previous value and perform retransmission of the random access preamble. For example, if the random access preamble power ramping pause condition is met, the terminal may retransmit the random access preamble but to stop power ramping of the random access preamble.

[0267] If the terminal determines to retransmit the random access preamble while reducing the transmission power as a result of assessing the above conditions, the terminal may perform retransmission by reducing the transmission power of the random access preamble while maintaining the PREAMBLE_POWER_RAMPING_COUNTER as it is from the previous value in step 1306. For example, if the terminal determines to reduce the transmission power as a result of assessing the uplink transmission power reduction condition, the terminal may decide to retransmit the random access preamble while reducing the transmission power.

[0268] If the terminal determines not to transmit the random access preamble based on the above conditions, the terminal may maintain the PREAMBLE_POWER_RAMPING_COUNTER value unchanged from the previous value and stop transmitting the random access preamble in step 1307. For example, if the power of the random access preamble transmission is determined to be '0' based on the uplink transmission power reduction condition determination, the terminal may determine not to transmit the random access preamble.

[0269] In another variation of the second embodiment, the terminal can perform a power ramping operation of the random access preamble for each uplink frequency constituting the 'processing unit'. That is, when the uplink frequency for transmitting the random access preamble is changed, the power ramping operation is initialized, but if the random access preamble has been transmitted previously through the same uplink frequency, the power ramping is performed based on the transmission power of the random access preamble transmitted previously through the same uplink frequency. This has the same effect as defining the PREAMBLE_POWER_RAMPING_COUNTER for each uplink frequency of the terminal and performing the power ramping operation for the same uplink frequency.

[0270] Although the names of the 5G system are used to describe the embodiments of the present disclosure, the names of SSB, MIB, SIB PDCCH, SIB PDSCH, message 1 to 4, etc. described above are merely examples, and it is possible to understand them as messages that include information of the same content as described above or perform the same role.

[0271] <Third embodiment>

[0272] The third embodiment describes a method for determining RA-RNTI when applying a mobile communication service combining multiple frequency bands to a random access procedure of a terminal.

[0273] The terminal calculates the RA-RNTI by referring to the time domain information of transmission occasion i, which is the time unit in which the random access preamble is transmitted, and the frequency domain information in which the random access preamble is transmitted. This can be generalized and expressed in a functional form as in the following <Mathematical Formula 6>.

[0274] [Equation 6]

[0275] RA-RNTI = f(time domain information in which the random access preamble is transmitted, frequency domain information in which the random access preamble is transmitted)

[0276] At this time, 'time domain information in which the random access preamble is transmitted' can be expressed as symbol and slot information to which the random access preamble is mapped, and 'frequency domain information in which the random access preamble is transmitted' can be expressed as RB information to which the random access preamble is mapped. The base station can calculate the RA-RNTI value by referring to the time and frequency domain information of the random access preamble received from the terminal. The base station scrambles the PDCCH scheduling the response message (RAR, message 2) for the received random access preamble with the calculated RA-RNTI and transmits it to the terminal. Therefore, the terminal monitors the PDCCH by utilizing the RA-RNTI value.

[0277] In a third embodiment, in a random access operation based on a "processing unit" comprised of multiple uplink frequencies, information on the uplink frequency at which the random access preamble is transmitted is used to calculate the RA-RNTI. Accordingly, the RA-RNTI calculation method of the third embodiment can be generalized as follows.

[0278] [Equation 7]

[0279] RA-RNTI = f(time domain information in which the random access preamble is transmitted, frequency domain information in which the random access preamble is transmitted, uplink frequency information in which the random access preamble is transmitted)

[0280] At this time, 'time domain information in which the random access preamble is transmitted' can be expressed as symbol and slot information to which the random access preamble is mapped, 'frequency domain information in which the random access preamble is transmitted' can be expressed as RB information to which the random access preamble is mapped, and 'uplink frequency information in which the random access preamble is transmitted' can be expressed as uplink frequency information to which the random access preamble is mapped among the uplink frequencies constituting the 'processing unit'.

[0281] According to the first embodiment described above, the 'uplink frequency information on which the random access preamble is transmitted' may be a 'random access configuration identifier' or a 'frequency indicator' that the base station notifies the terminal.

[0282] For example, the RA-RNTI according to the third embodiment can be calculated as in the following <Mathematical Formula 8>.

[0283] [Equation 8]

[0284] RA-RNTI = 1 + i_symbol + Nsymbol × i_slot + Nsymbol × Nslot × i_freq + Nsymbol × Nslot × Nfreq × i_carrier

[0285] At this time, the description of each parameter is as follows.

[0286] - i_symbol: index of the first symbol in the random access preamble (0 ≤ i_symbol < Nsymbol, where Nsymbol is the number of symbols that make up one slot)

[0287] - i_slot: Index of the first slot of the random access preamble within the frame (0 ≤ i_slot < Nslot, Nslot is the number of slots constituting one frame)

[0288] - i_freq: Frequency domain index of the random access preamble (0 ≤ i_freq < Nfreq, where Nfreq is the number of frequency domain blocks of the random access preamble multiplexed in the frequency domain)

[0289] - i_carrier: Uplink frequency index of the random access preamble (0 ≤ i_carrrier < Ncarrier, where Ncarrier is the number of uplink frequencies constituting the 'processing unit'). For example, i_carrier may correspond to the 'random access configuration identifier' or 'frequency indicator' that the base station notifies the terminal as described above.

[0290] <Example 4>

[0291] The fourth embodiment describes examples of terminal and base station procedures according to a preferred embodiment of the present invention. The terminal and base station procedures of the fourth embodiment may be performed in combination with at least one of the first to third embodiments.

[0292] FIG. 14 is a diagram illustrating an example of a random access procedure of a terminal applying a 'processing unit' composed of multiple frequencies when a base station operates the same according to one embodiment of the present invention.

[0293] In step 1401, the terminal synchronizes downlink time and frequency based on the SSB received from the base station and acquires a cell identifier (cell ID). The SSB is merely an example, and can be replaced with a physical signal transmitted from the base station for downlink time and frequency synchronization.

[0294] In step 1402, the terminal acquires the MIB, which is essential system information, and the system information (SIB). The terminal receives the PBCH using the cell ID acquired in step 1401, and acquires the MIB, which is essential system information, from the PBCH. The MIB includes CORESET information, which is a time-frequency resource to which the PDCCH is mapped. Therefore, the terminal can monitor the SIB PDCCH, which schedules the SIB PDSCH, in the CORESET. The terminal can receive the SIB PDSCH based on the scheduling information of the SIB PDCCH to acquire the SIB. The SIB includes cell-common transmission and reception-related control information, and may include, for example, random access-related control information, paging-related control information, and common control information for various physical channels. In addition, the SIB includes frequency-related control information, such as frequency domain location, bandwidth, and subcarrier spacing, for each of the uplink and downlink frequencies constituting the 'processing unit'. The above SIB PDCCH may include not only scheduling information for the SIB PDSCH, but also a random access preamble required for the terminal to perform a random access procedure, message 3, and other random access configuration identifiers for uplink signal transmission, or a frequency indicator indicating an uplink frequency.

[0295] In step 1403, the terminal applies various settings, such as frequency information and transmission power-related information to be applied to future random access procedures, from the acquired system information and random access setting identifier or frequency indicator.

[0296] At step 1404, the terminal performs transmission and reception operations with the base station using the random access settings applied above.

[0297] The steps described above may be modified, omitted, changed in order, or steps not described may be added to carry out the present invention.

[0298] FIG. 15 is a diagram illustrating an example of a base station procedure that supports a random access procedure of a terminal when the base station operates a 'processing unit' composed of multiple frequencies according to an embodiment of the present invention.

[0299] At step 1501, the base station transmits SSB.

[0300] In step 1502, the base station determines the random access settings to be applied to the terminal's transmission and reception operations during the random access procedure. The base station may consider factors such as the effect of reducing base station power consumption during this determination process. The base station may also perform step 1502 before step 1501.

[0301] In step 1503, the base station transmits system information. The base station may configure the random access configuration-related control information as system information. Additionally, it may configure a SIB PDCCH that includes a random access configuration identifier or frequency indicator.

[0302] At step 1504, the base station performs transmission and reception operations with the terminal using the random access settings determined above.

[0303] The steps described above may be modified, omitted, changed in order, or steps not described may be added to carry out the present invention.

[0304] In the description of the above figures 14 and 15, after the terminal's random access procedure is completed and the terminal is switched to a connected state, the base station can additionally instruct the terminal to change the frequency as needed.

[0305] FIG. 16 is a diagram illustrating an example of a terminal transceiver device 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 the illustration and description.

[0306] Referring to FIG. 16, the terminal may be configured with a transmitter (1604) including an uplink transmission processing block (1601), a multiplexer (1602), and a transmission RF block (1603), a receiver (1608) including a downlink reception processing block (1605), a demultiplexer (1606), and a reception RF block (1607), and a control unit (1609). The control unit (1609) may control each of the configuration blocks of the receiver (1608) for receiving a data channel or control channel transmitted by the base station as described above, and each of the configuration blocks of the transmitter (1604) for transmitting an uplink signal.

[0307] In the transmitter (1604) of the terminal, the uplink transmission processing block (1601) can generate a signal to be transmitted by performing processes such as channel coding and modulation. The signal generated in the uplink transmission processing block (1601) can be multiplexed with another uplink signal by a multiplexer (1602), and then transmitted to the base station after signal processing in the transmission RF block (1603).

[0308] The receiving unit (1608) of the terminal demultiplexes the signal received from the base station and distributes it to each downlink receiving processing block. The downlink receiving processing block (1605) can perform processes such as demodulation and channel decoding on the downlink signal of the base station to obtain control information or data transmitted by the base station. The receiving unit (1608) of the terminal can support the operation of the control unit (1609) by applying the output result of the downlink receiving processing block to the control unit (1609).

[0309] FIG. 17 is a block diagram showing an example of a configuration of a terminal according to one embodiment of the present disclosure.

[0310] As illustrated in FIG. 17, the terminal of the present disclosure may include a processor (1730), a transceiver (1710), and a memory (1720). However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more or fewer components than the components described above. In addition, the processor (1730), the transceiver (1710), and the memory (1720) may be implemented in the form of a single chip. According to one embodiment, the transceiver (1710) of FIG. 17 may include the transmitter (1604) and receiver (1608) of FIG. 16. In addition, the processor (1730) of FIG. 17 may include the control unit (1609) of FIG. 16.

[0311] According to one embodiment, the processor (1730) may control a series of processes that enable the terminal to operate according to the embodiments of the present disclosure described above. For example, the processor may control components of the terminal to perform a transmission and reception method of the terminal by a random access configuration identifier of the base station according to an embodiment of the present disclosure. There may be one or more processors (1730), and the processors (1730) may perform transmission and reception operations of the terminal in a wireless communication system that applies the operations of the present disclosure described above by executing a program stored in the memory (1720).

[0312] The transceiver (1710) can transmit and receive signals with a base station. The signals transmitted and received with the base station can include control information and data. The transceiver (1710) can be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-converts a received signal. However, the transceiver (1710) is only one embodiment, and the components of the transceiver (1710) are not limited to the RF transmitter and RF receiver. In addition, the transceiver (1710) can receive a signal through a wireless channel and output it to the processor (1730), and transmit a signal output from the processor (1730) through the wireless channel.

[0313] According to one embodiment, the memory (1720) can store programs and data necessary for the operation of the terminal. In addition, the memory (1720) can store control information or data included in signals transmitted and received by the terminal. The memory (1720) can be configured as a storage medium or a combination of storage media such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, the memory (1720) can be plural. According to one embodiment, the memory (1720) can store a program for performing transmission and reception operations of the terminal by the random access setting identifier of the base station, which are the embodiments of the present disclosure described above.

[0314] FIG. 18 is a block diagram showing an example of a configuration of a base station according to one embodiment of the present disclosure.

[0315] As illustrated in FIG. 18, the base station of the present disclosure may include a processor (1430), a transceiver (1810), and a memory (1820). However, the components of the base station are not limited to the examples described above. For example, the base station may include more or fewer components than the components described above. In addition, the processor (1830), the transceiver (1810), and the memory (1820) may be implemented in the form of a single chip.

[0316] The processor (1830) may control a series of processes so that the base station can operate according to the embodiments of the present disclosure described above. For example, the processor may control components of the base station to manage a random access procedure of a terminal by a random access configuration identifier of the base station according to the embodiments of the present disclosure. There may be one or more processors (1830), and the processors (1830) may control components of the base station to manage a random access procedure of a terminal by executing a program stored in the memory (1820) so as to manage the random access procedure of the terminal by the random access configuration identifier of the base station of the present disclosure described above.

[0317] The transceiver (1810) can transmit and receive signals with the terminal. The signals transmitted and received with the terminal can include control information and data. The transceiver (1810) can be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, an RF receiver that low-noise amplifies the received signal and down-converts the frequency, etc. However, the transceiver (1810) is only one embodiment, and the components of the transceiver (1810) are not limited to the RF transmitter and RF receiver. In addition, the transceiver (1810) can receive a signal through a wireless channel and output it to the processor (1830), and transmit a signal output from the processor (1830) through the wireless channel.

[0318] According to one embodiment, the memory (1820) may store programs and data required for the operation of the base station. In addition, the memory (1820) may store control information or data included in signals transmitted and received by the base station. The memory (1820) may be configured as a storage medium or a combination of storage media, such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, there may be a plurality of memories (1820). According to one embodiment, the memory (1820) may store a program for controlling components of the base station to manage a random access procedure of a terminal by a random access setting identifier of the base station, which are embodiments of the present disclosure described above.

[0319] In the specific embodiments of the present disclosure described above, components included in the present disclosure are expressed singularly or plurally, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0320] Meanwhile, the present specification and drawings have disclosed preferred embodiments of the present disclosure, and although specific terms have been used, they are used only in a general sense to easily explain the technical contents of the present disclosure and to help understand the invention, and are not intended to limit the scope of the present disclosure. It will be apparent to those skilled in the art to which the present disclosure pertains that other modified examples based on the technical idea of ​​the present disclosure are possible in addition to the embodiments disclosed herein. In addition, each of the above embodiments may be combined and operated with each other as needed. For example, the first embodiment, the second embodiment, the third embodiment, and the fourth embodiment may be implemented independently, or one or more embodiments may be combined with each other.

[0321] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. In a method performed by a terminal of a communication system, A step of receiving a synchronization signal block (SSB) in a first downlink frequency band from a base station; A step of receiving a PDCCH (physical downlink control information) for scheduling a SIB (system information block) based on the SSB from the base station; A step of receiving the SIB from the base station based on the PDCCH; and A step of performing transmission of a physical random access channel (PRACH) in a first uplink frequency band based on the above SIB is included, The SIB includes control information for at least one of a plurality of downlink frequency bands and control information for at least one of a plurality of uplink frequency bands, A method characterized in that the transmission power of the PRACH is associated with control information of the first downlink frequency band and control information of the first uplink frequency band.

2. In paragraph 1, Control information for at least one of the plurality of uplink frequency bands includes a random access setting indicator for each uplink frequency band, A method characterized in that the PDCCH includes a random access configuration indicator indicating the first uplink frequency band.

3. In paragraph 1, The SIB includes information indicating a connection relationship between at least one of the plurality of downlink frequency bands and at least one of the plurality of uplink frequency bands, A method characterized in that the first uplink frequency band is associated with the first downlink frequency band based on the connection relationship.

4. In paragraph 1, Further comprising a step of performing retransmission of the above PRACH, A method characterized in that, when the uplink frequency band for transmission of the PRACH and the uplink frequency band for retransmission of the PRACH are different, power ramping for retransmission of the PRACH is suspended.

5. In paragraph 1, A step of receiving DCI (downlink control information) scrambled based on RA-RNTI (random access-radio network temporary identifier) ​​from the base station; Further comprising a step of receiving a PDSCH (physical downlink shared channel) including a RAR (random access response) based on the DCI, A method characterized in that the RA-RNTI is determined based on information indicating the first uplink frequency band.

6. In a method performed by a base station of a communication system, A step of transmitting a synchronization signal block (SSB) to a terminal in a first downlink frequency band; A step of transmitting a PDCCH (physical downlink control information) scheduling a SIB (system information block) according to the SSB to the terminal; a step of transmitting the SIB according to the PDCCH; and A step of receiving a PRACH (physical random access channel) transmitted in the first uplink frequency band according to the SIB, The SIB includes control information for at least one of a plurality of downlink frequency bands and control information for at least one of a plurality of uplink frequency bands, A method characterized in that the transmission power of the PRACH is associated with control information of the first downlink frequency band and control information of the first uplink frequency band.

7. In paragraph 6, Control information for at least one of the plurality of uplink frequency bands includes a random access setting indicator for each uplink frequency band, A method characterized in that the PDCCH includes a random access configuration indicator indicating the first uplink frequency band.

8. In paragraph 6, The SIB includes information indicating a connection relationship between at least one of the plurality of downlink frequency bands and at least one of the plurality of uplink frequency bands, A method characterized in that the first uplink frequency band is associated with the first downlink frequency band based on the connection relationship.

9. In paragraph 6, Further comprising the step of receiving the retransmitted PRACH, A method characterized in that, when the uplink frequency band for transmission of the PRACH and the uplink frequency band for retransmission of the PRACH are different, power ramping for retransmission of the PRACH is suspended.

10. In paragraph 6, A step of receiving DCI (downlink control information) scrambled based on RA-RNTI (random access-radio network temporary identifier) ​​from the base station; Further comprising a step of receiving a PDSCH (physical downlink shared channel) including a RAR (random access response) based on the DCI, A method characterized in that the RA-RNTI is determined based on information indicating the first uplink frequency band.

11. In the terminal of the communication system, At least one transceiver; At least one processor communicatively connected to said at least one transceiver; and Communicably connected to at least one processor, and executable individually or in any combination of said at least one processor, so that said terminal Receives a synchronization signal block (SSB) in the first downlink frequency band from the base station, Receive PDCCH (physical downlink control information) for scheduling SIB (system information block) based on the SSB from the base station, Receive the SIB from the base station based on the PDCCH, A memory storing a command to perform transmission of a physical random access channel (PRACH) in a first uplink frequency band based on the above SIB, The SIB includes control information for at least one of a plurality of downlink frequency bands and control information for at least one of a plurality of uplink frequency bands, A terminal characterized in that the transmission power of the PRACH is associated with control information of the first downlink frequency band and control information of the first uplink frequency band.

12. In paragraph 11, Control information for at least one of the plurality of uplink frequency bands includes a random access setting indicator for each uplink frequency band, A terminal characterized in that the PDCCH includes a random access configuration indicator indicating the first uplink frequency band.

13. In paragraph 11, The SIB includes information indicating a connection relationship between at least one of the plurality of downlink frequency bands and at least one of the plurality of uplink frequency bands, A terminal characterized in that the first uplink frequency band is associated with the first downlink frequency band based on the connection relationship.

14. In paragraph 11, The above command causes the terminal to perform further retransmission of the PRACH, A terminal characterized in that, when the uplink frequency band for transmission of the PRACH and the uplink frequency band for retransmission of the PRACH are different, power ramping for retransmission of the PRACH is suspended.

15. In the base station of the communication system, At least one transceiver; At least one processor communicatively connected to said at least one transceiver; and Communicably connected to at least one processor, and executable individually or in any combination of said at least one processor, so that said base station Transmitting SSB (synchronization signal block) to the terminal in the first downlink frequency band, According to the above SSB, the PDCCH (physical downlink control information) scheduling the SIB (system information block) is transmitted to the terminal, Transmit the SIB according to the above PDCCH, A memory storing a command to receive a PRACH (physical random access channel) transmitted in the first uplink frequency band according to the SIB, The SIB includes control information for at least one of a plurality of downlink frequency bands and control information for at least one of a plurality of uplink frequency bands, A base station, characterized in that the transmission power of the PRACH is associated with control information of the first downlink frequency band and control information of the first uplink frequency band.

Images