Method and device for transmitting and receiving signals in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. A method performed by a user equipment (UE), according to one embodiment of the present disclosure, may comprise the steps of: receiving system information from a base station on an access carrier; transmitting a random access preamble on one or more data carriers on the basis of the received system information; and receiving a random access response to the random access preamble transmitted on one of the one or more data carriers.

Description

Method and device for transmitting and receiving signals in a wireless communication system

[0001] The present disclosure relates to a communication method of a wireless communication system, and to a method and device for efficient frequency use and reducing base station energy consumption.

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

[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 embodiment seeks to provide a device and method capable of effectively providing mobile communication services.

[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] The present disclosure relates to a 5G or 6G communication system for supporting higher data rates. A method performed by a user equipment (UE) according to one embodiment of the present disclosure may include the steps of receiving system information from a base station on an access carrier, transmitting a random access preamble on one or more data carriers based on the received system information, and receiving a random access response to the random access preamble transmitted on one of the one or more data carriers.

[0012] The disclosed embodiment provides a device and method for preventing excessive energy consumption of a base station and achieving high energy efficiency in a mobile communication system.

[0013] 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.

[0014] FIG. 1 is a diagram showing the basic structure of a time-frequency resource domain of a 5G system according to one embodiment of the present disclosure.

[0015] FIG. 2 is a diagram illustrating a random access procedure according to one embodiment of the present disclosure.

[0016] 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.

[0017] Figure 4 is a diagram showing the interrelationship between the frequency band and coverage of the present disclosure.

[0018] FIG. 5 is a diagram showing a system structure according to one embodiment of the present disclosure.

[0019] FIG. 6 is a diagram illustrating an initial connection procedure of a terminal according to one embodiment of the present disclosure.

[0020] FIG. 7 is a diagram illustrating a terminal procedure according to one embodiment of the present disclosure.

[0021] FIG. 8 is a diagram illustrating a base station procedure according to one embodiment of the present disclosure.

[0022] FIG. 9 is a diagram illustrating a base station procedure according to one embodiment of the present disclosure.

[0023] FIG. 10 is a diagram showing a terminal transceiver device according to one embodiment of the present disclosure.

[0024] FIG. 11 is a block diagram illustrating the structure of a terminal according to one embodiment of the present disclosure.

[0025] FIG. 12 is a block diagram illustrating the structure of a base station according to one embodiment of the present disclosure.

[0026] A method performed by a user equipment (UE) in a wireless communication system according to one embodiment of the present disclosure may include: receiving system information from a base station on an access carrier; transmitting a random access preamble on one or more data carriers based on the received system information; and receiving a random access response to the random access preamble transmitted on one of the one or more data carriers.

[0027] A method performed by a UE in a wireless communication system according to one embodiment of the present disclosure further includes the steps of: identifying a size of a DCI received on an access carrier based on a size of a maximum DL bandwidth; and monitoring a DCI on the access carrier based on the size of the identified DCI, wherein system information can be scheduled based on the DCI received through monitoring.

[0028] In a method performed by a UE in a wireless communication system according to one embodiment of the present disclosure, a data carrier for which a random access response is received is a data carrier satisfying a switch-on condition among one or more data carriers, and the switch-on condition may include at least one of whether a channel quality state of each data carrier exceeds a first threshold or whether a data rate required by the UE exceeds a second threshold.

[0029] In a method performed by a UE in a wireless communication system according to one embodiment of the present disclosure, a size of first frequency domain resource allocation control information for scheduling DL data of a data carrier may be determined based on a size of a DL bandwidth of a data carrier for which a random access response has been received, and a size of second frequency domain resource allocation control information for scheduling UL data of the data carrier may be determined based on a size of a UL bandwidth of the data carrier.

[0030] In a method performed by a UE in a wireless communication system according to one embodiment of the present disclosure, when a size of a first DCI (downlink control information) for DL ​​data determined based on a size of first frequency domain resource allocation control information and a size of a second DCI for UL data determined based on a size of second frequency domain resource allocation control information are different: zero padding may be performed on a DCI having a smaller size among the first DCI and the second DCI so that the sizes of the first DCI and the second DCI become the same, or truncation may be performed on a DCI having a larger size among the first DCI and the second DCI so that the sizes of the first DCI and the second DCI become the same.

[0031] A method performed by a base station in a wireless communication system according to one embodiment of the present disclosure includes the steps of: transmitting system information to a user equipment (UE) on an access carrier; and identifying a data carrier satisfying a switch-on condition among one or more data carriers through which a random access preamble is transmitted from the UE based on the transmitted system information, wherein UL data transmission or DL ​​data reception of the UE can be performed on the identified data carrier.

[0032] A method performed by a base station in a wireless communication system according to one embodiment of the present disclosure further includes the steps of: determining a size of a DCI to be transmitted on an access carrier based on a size of a maximum DL bandwidth; and transmitting the DCI on the access carrier based on the determined size of the DCI, wherein system information can be scheduled by the DCI received through monitoring.

[0033] In a wireless communication system according to one embodiment of the present disclosure, a UE includes: a transceiver; and at least one processor communicatively coupled to the transceiver; and a memory communicatively coupled to the at least one processor and storing one or more instructions, wherein the one or more instructions, when individually or collectively executed by the at least one processor, cause the UE to: receive system information from a base station on an access carrier; transmit a random access preamble on one or more data carriers based on the received system information; and receive a random access response to the transmitted random access preamble on one of the one or more data carriers.

[0034] In a wireless communication system according to one embodiment of the present disclosure, a base station includes a transceiver; and at least one processor communicatively coupled to the transceiver; and a memory communicatively coupled to the at least one processor and storing one or more instructions, wherein the one or more instructions, when individually or collectively executed by the at least one processor, cause the base station to: transmit system information to a user equipment (UE) on an access carrier; and identify a data carrier satisfying a switch-on condition among one or more data carriers on which a random access preamble has been transmitted from the UE based on the transmitted system information; and UL data transmission or DL ​​data reception of the UE can be performed on the identified data carrier.

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

[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 the physical layer, or a terminal transmits a signal to a base station using an uplink data channel of the physical layer. Higher layer signaling can be understood as 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) standards. However, this disclosure is not limited to these terms and names, and can be equally applied to systems conforming to other standards.

[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, and massive Machine Type Communication (MTC) services that support large-scale machine-to-machine communications.

[0047] While the transmission bandwidth of the existing mobile communication systems, LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)) and LTE-A (LTE-Advanced or E-UTRA Evolution), per single carrier is limited to a maximum of 20MHz, 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 ultra-high frequency bands from several GHz up to 100 GHz, where it is relatively easy to secure ultra-wide bandwidth frequencies, as candidate frequencies. Additionally, it is possible to secure wide bandwidth frequencies for the 5G system through frequency reallocation or allocation among 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 a signal by changing the beam direction, is additionally applied so that the common signal can reach terminals located at any location within the cell.

[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 TTI (Transmission Time Interval), 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, corresponding 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 the perspective of transmission time, 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 the terminal recognize the subcarrier spacing, CP length, etc. as common values. shows the subcarrier spacing configuration (μ) and subcarrier spacing ( ), which represents the relationship between CP length.

[0061] Table 1

[0062]

[0063] 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.

[0064] Table 2

[0065]

[0066] 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.

[0067] Table 3

[0068]

[0069] Coexistence or dual-mode operation is expected between 5G systems and at least existing LTE and / or LTE-A (hereinafter referred to as LTE / LTE-A) systems. This allows existing LTE / LTE-A systems to provide stable system operation to terminals, while the 5G system 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).

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] In the initial access phase, when a terminal first accesses the system, the terminal can synchronize downlink time and frequency from a synchronization signal transmitted by a base station through cell search, and obtain a cell identifier (cell ID). Then, the terminal can receive a Physical Broadcast Channel (PBCH) using the obtained cell ID, and obtain a Master Information Block (MIB), which is essential system information, from the PBCH. Additionally, the terminal can obtain cell-common transmission and reception-related control information by receiving system information (System Information Block, SIB) transmitted by the base station. The cell-common transmission and reception-related control information may include random access-related control information, paging-related control information, and common control information for various physical channels.

[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] 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.

[0077] FIG. 2 is a diagram illustrating a random access procedure according to one embodiment of the present disclosure.

[0078] 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 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.

[0079] In the second step (220), the base station transmits 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). Additionally, the base station may transmit uplink resources and power control commands to be used by the terminal as scheduling information. The scheduling information may include control information regarding the terminal's uplink transmission beam.

[0080] If the terminal does not receive the Random Access Response (RAR) (or message 2), which is scheduling information for message 3, from the base station within a predetermined time in 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).

[0081] 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 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.

[0082] 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).

[0083] 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, it may determine that the random access procedure has failed and restart from step 1 (210).

[0084] 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.

[0085] 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.

[0086] - Control information related to frequency bands supported by the terminal

[0087] - Control information related to channel bandwidth supported by the terminal

[0088] - Control information related to the maximum modulation method supported by the terminal

[0089] - Control information related to the maximum number of beams supported by the terminal

[0090] - Control information related to the maximum number of layers supported by the terminal

[0091] - Control information related to CSI reporting supported by the terminal

[0092] - Control information on whether the terminal supports frequency hopping

[0093] - Bandwidth-related control information when supporting carrier aggregation (CA)

[0094] - Control information on whether cross carrier scheduling is supported when carrier aggregation is supported.

[0095] 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.

[0096] 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.

[0097] Next, we will specifically explain downlink control information (DCI) in the 5G system.

[0098] 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.

[0099] 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 a Radio Network Temporary Identifier (RNTI) corresponding to the identity of the UE. 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 can know that the message was transmitted to the UE.

[0100] For example, a DCI scheduling a PDSCH for System Information (SI) may be scrambled with SI-RNTI. A DCI scheduling a PDSCH for a Random Access Response (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).

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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 terminal 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 terminal through higher layer signaling (e.g., System Information, Master Information Block (MIB), Radio Resource Control (RRC) signaling). Configuring a CORESET to the terminal 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 terminal to configure the CORESET may include at least some of the information included in .

[0105] Table 4

[0106]

[0107] CORESET is in the frequency domain It can be composed of RBs and in the time domain ∈{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.

[0108] 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.

[0109] Table 5

[0110]

[0111] 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.

[0112] The search space of the PDCCH is described as follows. The number of CCEs required to transmit the PDCCH can be 1, 2, 4, 8, or 16 depending on the aggregation level (AL), and different numbers of CCEs can be used for link adaptation of the downlink control channel. For example, when AL=L, a single downlink control channel can be transmitted through L CCEs. The UE performs blind decoding, which detects a signal without knowing information about the downlink control channel. For this purpose, a search space representing a set of CCEs can be defined. The search space is a set of downlink control channel candidates consisting of CCEs that the UE should attempt to decode at a given aggregation level. Since there are various aggregation levels that create a single group with 1, 2, 4, 8, or 16 CCEs, the UE can have multiple search spaces. A search space set can be defined as the set of search spaces at all established aggregation levels.

[0113] 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.

[0114] 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 within the slot for the search space, the search space type (common search space or terminal-specific search space), the combination of the DCI format and RNTI to be monitored in the corresponding search space, the CORESET index to be monitored for the search space, etc. to the terminal. For example, the parameters for the search space for the PDCCH may include information such as the following .

[0115] Table 6

[0116]

[0117]

[0118] 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.

[0119] 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.

[0120] 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.

[0121] - 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

[0122] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0123] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0124] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0125] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0126] 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.

[0127] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0128] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0129] RNTIs may follow the following definitions and uses:

[0130] C-RNTI (Cell RNTI): For terminal-specific PDSCH or PUSCH scheduling purposes.

[0131] TC-RNTI (Temporary Cell RNTI): For terminal-specific PDSCH scheduling purposes

[0132] CS-RNTI (Configured Scheduling RNTI): Used for semi-static terminal-specific PDSCH scheduling.

[0133] RA-RNTI (Random Access RNTI): Used for PDSCH scheduling in the random access phase.

[0134] P-RNTI (Paging RNTI): Used for scheduling PDSCH where paging is transmitted.

[0135] SI-RNTI (System Information RNTI): Used for scheduling PDSCH where system information is transmitted.

[0136] INT-RNTI (Interruption RNTI): Used to indicate whether PDSCH is punctured.

[0137] TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to indicate power control commands for PUSCH.

[0138] TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to indicate power control commands for PUCCH.

[0139] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to indicate power control commands for SRS.

[0140] The DCI formats described above can follow the definitions shown in below.

[0141] Table 7

[0142]

[0143] CORESET p, the search space of aggregation level L in the search space set s can be expressed as the following mathematical formula.

[0144] <Mathematical Formula 1>

[0145]

[0146] - L: Integration level

[0147] - n CI : Carrier Index

[0148] - N CCE,p : Total number of CCEs existing within the control resource set p

[0149] - n μ s,f : slot index

[0150] - M (L) p,s,max : Number of PDCCH candidates for aggregation level L

[0151] - m snCI = 0, ..., M (L) p,s,max -1: PDCCH candidate index of aggregation level L

[0152] - i = 0, ..., L-1

[0153] - = , , =39827, , ,

[0154] - n RNTI : Terminal identifier

[0155] The value can be 0 for a common search space.

[0156] 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.

[0157] Below, we will specifically describe how a terminal measures channel conditions and reports them to a base station in a 5G communication system.

[0158] Channel state information (CSI) may include the following information:

[0159] - 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.

[0160] - Precoding Matrix Indicator (PMI): Precoding matrix indicator information selected by the terminal.

[0161] - CRI (CSI-RS resource indicator): CSI-RS information measured by the terminal

[0162] - RI (Rank Indicator): Rank indication information selected by the terminal

[0163] - LI (Layer indicator): Indication information for the best layer among the precoding matrices reported by the terminal.

[0164] - SSBRI (SS / PBCH block resource indicator): SSB information measured by the terminal

[0165] - L1-RSRP (Reference Signal Received Power): L1 RSRP information measured by the terminal

[0166] The base station can control time and frequency resources for the aforementioned CSI measurement and reporting of the terminal.

[0167] 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).

[0168] 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).

[0169] Aperiodic CSI reporting can be triggered by the “CSI request” field of the aforementioned DCI format 0_1 ​​corresponding to the scheduling DCI for PUSCH.

[0170] To support ultra-high-speed data services, data rates can be increased through spatial multiplexing using multiple transmit / receive antennas. Typically, the number of power amplifiers (PAs) required increases proportionally to the number of transmit antennas installed at a base station or terminal. The maximum output of the base station and terminal is determined by the characteristics of the PA, and the maximum output of the base station generally varies depending on the cell size covered by the base station. The maximum output is usually expressed in dBm. The maximum output of the terminal is typically 23 dBm or 26 dBm.

[0171] As an example, a commercial 5G base station can operate at a 3.5 GHz frequency band, equipped with 64 transmit antennas and corresponding 64 power amplifiers, with a bandwidth of 100 MHz. Ultimately, the energy consumption of the base station increases in proportion to the power amplifier output and operating time. Compared to LTE base stations, 5G base stations have a relatively high operating frequency band, allowing for a wider bandwidth and a larger number of transmit antennas. While these characteristics directly increase data rates, they come at the cost of increased base station energy consumption. Therefore, the more base stations that comprise a mobile communications network, the greater the energy consumption of the entire mobile communications network.

[0172] As mentioned above, the energy consumption of a base station is largely determined by the operation of the power amplifier. Since the power amplifier is involved in the base station's transmission operation, the downlink (DL) transmission operation of the base station is closely related to its energy consumption. Comparatively, the uplink (UL) reception operation of the base station does not account for a significant portion of its energy consumption. The physical channels and physical signals transmitted by the base station in the downlink are as follows.

[0173] - PDSCH (Physical Downlink Shared Channel): A downlink data channel containing data to be transmitted to one or more terminals.

[0174] - PDCCH (Physical Downlink Control Channel): A downlink control channel that contains scheduling information for the PDSCH and PUSCH (Physical Uplink Control Channel). Alternatively, the PDCCH alone can transmit control information such as slot format and power control commands without the PDSCH or PUSCH to be scheduled. Scheduling information includes resource information to which the PDSCH or PUSCH is mapped, HARQ-related information, power control information, etc.

[0175] - PBCH (Physical Broadcast Channel): A downlink broadcast channel that provides MIB (Master Information Block), which is essential system information required for transmission and reception of data channels and control channels of the terminal.

[0176] - PSS (Primary Synchronization Signal): This signal serves as the basis for DL ​​time / frequency synchronization and provides some cell ID information.

[0177] - SSS (Secondary Synchronization Signal): A signal that serves as a basis for DL ​​time and / or frequency (hereinafter referred to as time / frequency) synchronization and provides some remaining information such as cell ID.

[0178] - DM-RS (Demodulation Reference Signal): Reference signal for terminal channel estimation for each of PDSCH, PDCCH, and PBCH.

[0179] - CSI-RS (Channel-state Information Reference Signal): A downlink signal that serves as a basis for measuring the terminal's downlink channel status.

[0180] - PT-RS (Phase-tracking Reference Signal): Downlink signal for phase tracking

[0181] From a base station energy conservation perspective, suspending downlink transmission at the base station can significantly reduce base station energy consumption by halting power amplifier operation. Furthermore, the reduced operation of other base station components, including the baseband, in addition to the power amplifier can also lead to additional energy savings. Similarly, even though uplink reception accounts for a relatively small portion of the base station's overall energy consumption, suspending uplink reception can yield additional energy savings.

[0182] The downlink transmission behavior of a base station is fundamentally determined by the amount of downlink traffic. For example, if there is no data to transmit to a terminal via the downlink, the base station does not need to transmit the PDSCH and the PDCCH for scheduling the PDSCH. Alternatively, if transmission can be temporarily delayed for reasons such as the data being insensitive to transmission delay, the base station may not transmit the PDSCH and / or PDCCH. For convenience of explanation below, this method of reducing base station energy consumption by not transmitting or appropriately controlling PDSCH and / or PDCCH transmission associated with data traffic is referred to as "Base Station Energy Saving Method 1-1."

[0183] In contrast, physical channels and physical signals such as PSS, SSS, PBCH, and CSI-RS have the characteristic of being repeatedly transmitted at a predetermined, promised cycle regardless of data transmission to the terminal. Therefore, even if the terminal does not receive data, it can continuously update downlink time / frequency synchronization, downlink channel status, radio link quality, etc. In other words, PSS, SSS, PBCH, and CSI-RS necessarily require downlink transmission regardless of downlink data traffic, and thus induce base station energy consumption. Therefore, base station energy can be saved by adjusting the transmission of signals unrelated to (or with low relevance to) data traffic to occur less frequently (hereinafter referred to as 'base station energy saving method 1-2').

[0184] By using 'Base Station Energy Saving Method 1-1' or 'Base Station Energy Saving Method 1-2', the energy saving effect of the base station can be maximized by stopping or minimizing the operation of the base station's power amplifier and related RF devices, baseband devices, etc. during the time period when the base station does not perform downlink transmission.

[0185] Alternatively, the energy consumption of the base station can be reduced by switching off some of the base station antennas or power amplifiers (hereinafter referred to as 'Base Station Energy Saving Method 2'). In this case, the energy saving effect of the base station may be counterproductive, such as a decrease in cell coverage or a decrease in throughput. For example, there may be a base station equipped with 64 transmit antennas and corresponding 64 power amplifiers in the 3.5 GHz frequency band described above and operating with a bandwidth of 100 MHz. In order to save energy for such a base station, if only 4 transmit antennas and 4 power amplifiers are activated for a certain period of time and the rest are switched off, the base station energy consumption during that period is reduced to approximately 1 / 16 (= 4 / 64). When only four transmit antennas and four power amplifiers are activated for a given time period and the rest are switched off, it becomes difficult to achieve the cell coverage and throughput assuming the existing 64 antennas and power amplifiers due to the decrease in maximum transmit power and beamforming gain.

[0186] The above-described base station energy saving methods 1-1, 1-2, and 2 can be applied and operated individually, or can be operated in combination with each other.

[0187] In the following description, the base station mode that applies an operation for saving base station energy is called the base station power saving mode (ES mode) to distinguish it from the general base station operation, and the base station mode that applies the general base station operation is called the base station normal mode (Normal mode).

[0188] 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.

[0189] As mentioned above, the frequency band utilized by 5G systems is wide, ranging from hundreds of MHz to tens of GHz. Figure 4 shows the interrelationship among frequency bands, coverage, and bandwidth. Figure 4 shows the frequency bands of low band (401), mid band (402), high band (403), and ultra high band (404). In general, the lower the frequency band, the greater the coverage due to relatively low path loss, and the higher the frequency band, the smaller the coverage due to relatively high path loss. In the low frequency band, the frequency available for mobile communication is fragmented, resulting in a small bandwidth, whereas in the high frequency band, it is relatively easy to secure a wide bandwidth, 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 6G mobile communication systems, 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 5G system frequency bands across multiple bands and then provide mobile communication services through 5G CA by combining the frequencies in these bands. Similarly, 6G mobile communication systems can provide mobile communication services by combining 6G frequencies with existing 4G or 5G frequencies, or by combining 6G frequencies together. As mentioned above, because characteristics such as coverage and bandwidth vary depending on the frequency band, mobile communication services that combine multiple frequency bands are becoming increasingly active rather than mobile communication services that rely on a single frequency band.

[0190] The operation of the system proposed in the present disclosure is described below through specific examples.

[0191] In the present disclosure, when configuring a mobile communication system combining multiple frequencies, a method is proposed to limit channels transmitted and received by a terminal and a base station for each frequency in order to reduce power consumption of the terminal and base station, thereby avoiding unnecessary channel transmission and reception, and to determine the size of control information constituting a downlink control channel for each frequency.

[0192] In the first embodiment of the present disclosure, a method is proposed in which, at the initial connection stage of a terminal, a frequency at which the terminal receives a downlink channel and a frequency at which the terminal transmits an uplink channel are separated, and accordingly, a channel received by the terminal from a base station is differently designated for each frequency.

[0193] In a second embodiment of the present disclosure, a method for determining the size of control information constituting a downlink control channel for each frequency is proposed.

[0194] The above embodiments are distinguished for convenience in describing implementations according to the present disclosure. All or part of the embodiments may be selectively combined to achieve various implementations of the present disclosure. While the embodiments of the present disclosure are described based on a 5G mobile communication system, they can also be generally applied to next-generation mobile communication systems, such as 6G mobile communication, unless otherwise specified.

[0195] Below, a description of each specific embodiment is as follows.

[0196] <Example 1>

[0197] The first embodiment describes a method for separating the frequency at which the terminal receives a downlink channel and the frequency at which the terminal transmits an uplink channel during the initial connection stage of the terminal, and thereby designating the channel that the terminal receives from the base station differently for each frequency.

[0198] The first embodiment describes a communication system architecture that combines frequencies of multiple bands. The frequencies may be adjacent or separated in the frequency domain.

[0199] Hereinafter, the main concepts of the first embodiment will be described with reference to FIG. 5. The communication system of FIG. 5 consists of a carrier operating at a frequency F1 (hereinafter referred to as an 'access carrier' for convenience of explanation, 501) and a carrier operating at a frequency F2 (hereinafter referred to as a 'data carrier', 502) (F1 < F2). F1 has an advantage in coverage due to its relatively low frequency band, but has limitations in providing high-speed data services due to bandwidth constraints. F2 has a relative weakness in coverage due to its relatively high frequency band, but has an advantage in providing high-speed data services due to its relatively wide bandwidth. The size of the circles shown in FIG. 5 indicates the coverage size that each carrier can provide. In the example of FIG. 5, it indicates that multiple 'data carriers (502)' coexist within the coverage of an 'access carrier (501)'. The 'access carrier (501)' and the 'data carrier (502)' can be connected to each other wired or wirelessly to enable smooth cooperation. The base station and terminal applying the first embodiment are configured to support operations in F1 and F2. Therefore, coverage and high-speed data services can be provided appropriately through the first embodiment. In the present disclosure, the base station may be implemented to support a combined form of an 'access carrier (501)' and a 'data carrier (502)'. In addition, according to another embodiment, the present disclosure may be implemented so that the 'access carrier (501)' and the 'data carrier (502)' are supported by separate base stations. If the 'access carrier (501)' and the 'data carrier (502)' are implemented as a single base station, the 'access carrier (510)' and the 'data carrier (502)' may be referred to as transmission reception points (TRPs) that use different frequencies, respectively.

[0200] The 'access carrier (501)' provides essential information of the communication system, such as the aforementioned synchronization signal, PBCH, and system information, and maintains a switched-on state to support all terminals in the system regardless of the status of the terminals. The base station in the switched-on state can keep the transmission block and the reception block powered on and perform normal transmission and reception operations. The terminal starts the initial access operation through the 'access carrier (501)'. The 'data carrier (502)' switches between the switched-on state and the switched-off state as needed. In the switched-off state, the base station power is kept partially or completely off. If there is no terminal to be serviced within the 'data carrier (502)', the 'data carrier (502)' can switch to the switched-off state to prevent unnecessary base station energy consumption. Unlike the 'access carrier (501)', the 'data carrier (502)' can increase frequency efficiency by omitting or minimizing the transmission of essential information provided to the terminal. The above-mentioned switch-off state may include an operation in which the transmission function is turned off and the reception function is turned on. In other words, power consumption can be reduced by turning off the transmitter, which consumes relatively large amounts of power, and uplink signals that the terminal may transmit at any time can be received immediately without delay.

[0201] The first embodiment can be explained by classifying it into steps 1, 2, and 3 depending on whether the terminal is in the initial connection stage. The terminal state can be broadly classified into a connected state (or RRC_CONNECTED state) and an idle state (or RRC_IDLE state). When the terminal is powered on, the terminal goes through a series of initial access procedures, such as synchronizing the time and frequency with the base station, acquiring system information from the base station, and performing a random access procedure, as a preliminary preparation step for performing data communication with the base station. The terminal state in the initial connection stage is called the idle state. Upon completing the initial connection stage, the terminal now transitions to the connected state and can perform one-to-one data transmission and reception with the base station. For convenience of explanation, steps 1, 2, and 3 will be described below with reference to FIG. 6. FIG. 6 illustrates a series of procedures following power-on of a terminal (601) within a communication system comprising an 'access carrier' (602) operating at frequency F1 and two 'data carriers' ('data carrier 1' (603), 'data carrier 2' (604)) operating at frequency F2.

[0202] - Step 1 (621): A step in which the terminal (601) initiates an initial connection with the base station.

[0203] As described above, the 'access carrier' (602) maintains a switched-on state to support all terminals in the system regardless of the status of the terminals. In contrast, the 'data carrier' (603) maintains a switched-off state to expect a base station energy-saving effect. When a user turns on the power of the terminal (601), the terminal (601) obtains a synchronization signal, PBCH, system information, etc. through the 'access carrier' (602) as a preliminary preparation step for performing data communication with the base station (610). Through this, the terminal (601) can match the time-frequency synchronization with the 'access carrier' (602) and obtain information necessary for the random access procedure.

[0204] - Step 2 (622): A step in which the terminal (601) continues initial connection with the base station.

[0205] At least some 'data carriers' (e.g., 603) are expected to have a partial base station energy saving effect by turning on the transmission operation but turning off the reception operation. The idle terminal (601) can obtain a synchronization signal, PBCH, system information, etc. through the 'access carrier' (602), and based on this, initiate a random access procedure toward the 'data carrier'. The random access preamble transmitted by the terminal (601) can be received through one or more 'data carriers' (603, 604) (611).

[0206] In the case of multiple 'data carriers' (603, 604) as shown in Fig. 6, the basis for the base station's determination to switch on a given 'data carrier' may include whether the channel quality status between the terminal and the corresponding 'data carrier' exceeds a predetermined threshold A, whether the data rate required by the terminal corresponds to a high-speed data service exceeding a predetermined threshold B, etc. Control information related to the thresholds A and B may be set in advance by the base station to each 'data carrier' through signaling. Each of the multiple 'data carriers' (603, 604) may determine by itself whether it satisfies the switch-on condition from the random access preamble received from the terminal or may report it to the 'access carrier' (602). A 'data carrier' that does not satisfy the switch-on condition remains in a switched-off state, and the base station energy saving effect is expected. The 'access carrier' (602) may determine whether to switch on or off the 'data carrier' and notify the corresponding 'data carrier' through signaling (612). In the example of FIG. 6, it is assumed that the 'access carrier' (602) decides to switch on 'data carrier 1' (603) and switch off 'data carrier 2' (604). Thereafter, the 'data carrier 1' (603) and the terminal (601) can complete the random access procedure by successfully exchanging signals corresponding to message 2, message 3, message 4, and HARQ-ACK of the random access procedure described above (613, 614, 615, 616).

[0207] - Step 3 (623): A step in which the terminal (601) completes initial connection and communicates with the base station.

[0208] If the terminal (601) succeeds in the above random access procedure, the terminal (601) completes the initial access procedure. The terminal (601) that has completed the initial access procedure can perform one-to-one data communication with 'data carrier 1' (603) (617).

[0209] According to the above steps 1, 2, and 3, the 'access carrier' (602) is responsible for transmitting synchronization signals, PBCH, and system information to support the idle terminal (601). That is, the terminal (601) performs a reception operation of the downlink signal through the 'access carrier' (602). The 'data carrier' (e.g., 603) receives an uplink signal transmitted by the idle terminal (601) for a random access procedure and is responsible for transmitting a corresponding downlink signal. In addition, the 'data carrier' (e.g., 603) is responsible for transmitting a downlink signal and receiving an uplink signal to perform one-to-one communication with the connected terminal (601). That is, the terminal (601) performs a transmission and reception operation for a random access procedure and a transmission and reception operation in a connected state through the 'data carrier' (e.g., 603).

[0210] According to the above description, the terminal (601) in an idle state belongs to one of the steps 1 and 2, and the terminal (601) in a connected state belongs to the step 3.

[0211] According to the first embodiment, the downlink channels that the terminal receives through the 'access carrier' and the 'data carrier' are as follows.

[0212] - The downlink channels received by an idle terminal through an ‘access carrier’ include at least the following channels.

[0213] PBCH

[0214] PDSCH that transmits system information and PDCCH that schedules the PDSCH: DCI, which is control information that constitutes the PDCCH, is scrambled with SI-RNTI, an identifier that indicates that system information is scheduled.

[0215] PDSCH that transmits paging information and PDCCH that schedules the PDSCH: DCI, which is control information that constitutes the PDCCH, is scrambled with P-RNTI, which is an identifier that indicates that paging information is scheduled.

[0216] - The downlink channels received by an idle terminal from a 'data carrier' include at least the following channels.

[0217] PDSCH transmitting Message 2 and PDCCH scheduling the PDSCH: DCI, which is control information constituting the PDCCH, is scrambled with RA-RNTI, an identifier indicating that message 2 is scheduled.

[0218] PDSCH transmitting Message 4 and PDCCH scheduling the PDSCH: DCI, which is control information constituting the PDCCH, is scrambled with Temporary C-RNTI, which is an identifier indicating that message 4 is scheduled.

[0219] - The downlink channel received by the connected terminal from the ‘data carrier’ includes at least the following channels.

[0220] PDSCH that transmits unicast data for a terminal and PDCCH that schedules the PDSCH: DCI, which is control information that constitutes the PDCCH, is scrambled with C-RNTI, which is an identifier that indicates that unicast data for a terminal is scheduled.

[0221] PDCCH for scheduling PUSCH that the terminal wants to transmit on uplink: DCI, which is control information constituting the PDCCH, is scrambled with C-RNTI, an identifier indicating that unicast data for the terminal is scheduled.

[0222] According to the first embodiment, an idle terminal does not perform uplink transmission to an "access carrier." Furthermore, a connected terminal neither receives a downlink channel nor performs uplink transmission to an "access carrier." Therefore, the functionality of the "access carrier" can be simplified. For example, an "access carrier" can operate with a relatively smaller bandwidth than a "data carrier" and can only have a downlink transmission function without an uplink reception function.

[0223] <Second embodiment>

[0224] The second embodiment describes a method for determining the size of DCI, which is control information for configuring a downlink control channel, for each frequency or for each 'access carrier' and 'data carrier' in a mobile communication system configured as in the first embodiment described above.

[0225] According to the first embodiment, the 'access carrier' has the characteristics of having a relatively small bandwidth and being able to omit the uplink reception function. On the other hand, the 'data carrier' has the characteristics of having a relatively large bandwidth and being equipped with both the downlink transmission function and the uplink reception function. Accordingly, the size of the DCI transmitted by the 'access carrier' and the 'data carrier' respectively needs to be adjusted according to the above characteristics. For the convenience of the following explanation, the bandwidth of the 'access carrier' and the 'data carrier' for the downlink and uplink are respectively expressed as follows. The bandwidth below can be expressed in units of RBs.

[0226] - Downlink bandwidth of 'access carrier': BW_access,DL

[0227] - Uplink bandwidth of 'access carrier': BW_access,UL

[0228] - Downlink bandwidth of 'data carrier': BW_data,DL

[0229] - Uplink bandwidth of 'data carrier': BW_data,UL

[0230] As described above, if the uplink reception function of the 'access carrier' is omitted, it is assumed that BW_access,UL = 0.

[0231] The main purpose of DCI transmitted by a base station through an 'access carrier' is to schedule system information or paging information transmitted by the base station in the downlink within the 'access carrier'. Therefore, since the frequency domain resource allocation size to which the system information or paging information is mapped is limited to a maximum of BW_access,DL, the DCI size is also determined accordingly. For example, the size (bits) of frequency domain resource allocation control information within the DCI of the 'access carrier' can be determined as in the following <Mathematical Formula 2>.

[0232] <Mathematical Formula 2>

[0233] ceil (log2(BW_access,DL (BW_access,DL + 1) / 2))

[0234] At this time, ceil (x) means the integer closest to x that is x rounded up.

[0235] In addition, since the above system information or paging information is information commonly applied to cells, the DCI that schedules it can be placed in a common search space. Accordingly, the terminal can determine the maximum size of the DCI searched in the 'access carrier' by referring to BW_access,DL, and monitor the DCI in the common search space of the 'access carrier', thereby alleviating the complexity of DCI monitoring.

[0236] Meanwhile, the DCI transmitted by the base station on the "data carrier" is utilized for various purposes, such as scheduling unicast data for downlink and uplink, or scheduling downlink data in random access procedures. Therefore, the DCI size of the "data carrier" can be determined through the following several methods.

[0237] - Method 1 for determining the DCI size of a 'data carrier': The size of the DCI for scheduling downlink data is determined according to the downlink bandwidth of the 'data carrier', and the size of the DCI for scheduling uplink data is determined according to the uplink bandwidth of the 'data carrier'. For example, the size (bits) of frequency domain resource allocation control information in the DCI for scheduling downlink data of the 'data carrier' can be determined as in the following <Mathematical Formula 3>.

[0238] <Mathematical Formula 3>

[0239] ceil (log2(BW_data,DL (BW_data,DL + 1) / 2))

[0240] And, the size (bits) of the frequency domain resource allocation control information within the DCI that schedules the uplink data of the 'data carrier' can be determined as in the following <Mathematical Formula 4>.

[0241] <Mathematical Formula 4>

[0242] ceil (log2(BW_data,UL (BW_data,UL + 1) / 2))

[0243] - Method 2 for determining the DCI size of a 'data carrier': Unlike the above determination method 1, the size of the DCI for scheduling the downlink data of the 'data carrier' and the size of the DCI for scheduling the uplink data of the 'data carrier' are adjusted to be the same. To this end, the size of each DCI is provisionally calculated through the above method 1, and then, if the sizes of the DCIs are not the same, the DCI sizes are adjusted to be the same by additionally inserting '0' into the DCI of a smaller size (zero padding) or by truncating a part of the DCI of a larger size (truncation). This can alleviate the complexity of the terminal monitoring the DCI of the 'data carrier'.

[0244] - Method 3 for determining the DCI size of a 'data carrier': This is a compromise between the above-described determination methods 1 and 2, and is applied differently depending on the search space in which the DCI is deployed. For example, the above-described determination method 2 may be applied to DCI deployed in a common search space, and the above-described determination method 1 may be applied to DCI deployed in a terminal-specific search space.

[0245] The base station may decide which of the above decision methods to apply and inform the terminal through signaling, or may apply one method agreed upon in advance with the terminal.

[0246] <Third Embodiment>

[0247] A third embodiment describes examples of terminal procedures and base station procedures according to preferred embodiments of the present disclosure. The terminal procedures and base station procedures of the third embodiment may be performed in combination with at least one of the first and second embodiments.

[0248] FIG. 7 is a diagram illustrating an example of a terminal procedure applied when a base station operates by combining an 'access carrier' and a 'data carrier' according to one embodiment of the present disclosure.

[0249] In step 701, the terminal receives a reference signal via an "access carrier." The reference signal includes a synchronization signal or a CSI-RS. Additionally, the terminal receives a PBCH and system information via the "access carrier." The system information may include information required for a random access procedure. When determining the size of the DCI received via the "access carrier," the terminal follows the method of the second embodiment described above.

[0250] In step 702, the terminal transmits a random access preamble via a "data carrier." The random access preamble transmitted by the terminal can be received by one or more "data carriers." The base station determines which "data carrier" will be used to transmit the response signal to the terminal's random access preamble.

[0251] In step 703, the terminal receives a random access response (message 2) signal via the 'data carrier' and continues the random access procedure using the 'data carrier'. At this time, the terminal can additionally receive a reference signal transmitted via the 'data carrier'. If the random access procedure is successfully completed, the terminal can perform one-to-one data communication with the 'data carrier' in a subsequent step. When determining the size of the DCI received via the 'data carrier', the terminal follows the method of the second embodiment described above.

[0252] The steps described above may be modified, omitted, changed in order, or steps not described may be added to carry out the present invention.

[0253] FIG. 8 is a diagram illustrating an example of a procedure of an 'access carrier' applying the same when operating an 'access carrier' and a 'data carrier' in combination according to one embodiment of the present disclosure.

[0254] In step 801, the base station transmits a reference signal to the terminal via an "access carrier." The reference signal includes a synchronization signal or a CSI-RS. Additionally, a PBCH and system information may be transmitted to the terminal via the "access carrier." The system information may include information required for a random access procedure. The base station follows the method of the second embodiment described above when determining the size of the DCI transmitted via the "access carrier."

[0255] In step 802, the base station supporting the 'access carrier' can determine which 'data carrier' to switch on (or wake up) and instruct the 'data carrier' to switch on. At this time, the base station supporting the 'access carrier' can receive a report on whether the 'data carrier' described above satisfies the switch-on condition and, based on this, determine whether to switch the 'data carrier' on.

[0256] The steps described above may be modified, omitted, rearranged, or even have non-described steps added to perform the present disclosure. For example, step 802 may be replaced with an operation in which an upper network node managing the "access carrier" determines whether the "data carrier" is switched on. Alternatively, step 802 may be omitted, and the base station or TRP utilizing the "data carrier" may switch to the switched-on state based on its own judgment.

[0257] FIG. 9 is a diagram illustrating an example of a procedure of a 'data carrier' applying the same when operating an 'access carrier' and a 'data carrier' in combination according to one embodiment of the present invention.

[0258] In step 901, a base station or TRP using a 'data carrier' receives a random access preamble from a terminal. The base station or TRP using the 'data carrier' can report to the base station or TRP using the 'access carrier' whether the received random access preamble satisfies the switch-on condition of the 'data carrier' described above. In step 902, the base station or TRP using the 'data carrier' receives an instruction from the base station or TRP using the 'access carrier' as to whether to switch on. The 'data carrier' can be switched on according to the switch-on instruction.

[0259] In step 903, the random access procedure continues with the terminal via the "data carrier." At this time, a reference signal may be additionally transmitted to the terminal via the "data carrier." If the random access procedure is successfully completed, the base station or TRP using the "data carrier" and the terminal may perform one-to-one data communication in subsequent steps. The base station follows the method of the second embodiment described above when determining the size of the DCI transmitted via the "data carrier."

[0260] The steps described above may be modified, omitted, rearranged, or the present invention may be implemented by adding steps not described above. For example, step 902 may be replaced with an operation in which a higher network node managing the "data carrier" instructs the switch-on state. Alternatively, step 902 may be replaced with an operation in which the base station or TRP utilizing the "data carrier" switches to the switch-on state at its own discretion.

[0261] FIG. 10 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, the illustration and description of devices not directly related to the present disclosure may be omitted.

[0262] Referring to FIG. 10, the terminal may be configured with a transmitter (1004) including an uplink transmission processing block (1001), a multiplexer (1002), and a transmission RF block (1003), a receiver (1008) including a downlink reception processing block (1005), a demultiplexer (1006), and a reception RF block (1007), and a control unit (1009). As described above, the control unit (1009) may control each of the configuration blocks of the receiver (1008) for receiving a data channel or control channel transmitted by the base station and each of the configuration blocks of the transmitter (1004) for transmitting an uplink signal.

[0263] In the transmitter (1004) of the terminal, the uplink transmission processing block (1001) 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 (1001) can be multiplexed with another uplink signal by a multiplexer (1002), and then transmitted to the base station after signal processing in the transmission RF block (1003).

[0264] The receiving unit (1008) 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 (1005) 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 (1008) of the terminal can support the operation of the control unit (1009) by applying the output result of the downlink receiving processing block to the control unit (1009).

[0265] FIG. 11 is a block diagram showing an example of a configuration of a terminal according to one embodiment of the present disclosure.

[0266] As illustrated in FIG. 11, the terminal of the present disclosure may include a processor (1130), a transceiver (1110), and a memory (1120). 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 (1130), the transceiver (1110), and the memory (1120) may be implemented in the form of a single chip. According to one embodiment, the transceiver (1110) of FIG. 11 may include the transmitter (1004) and receiver (1008) of FIG. 10. In addition, the processor (1130) of FIG. 11 may include the control unit (1009) of FIG. 10.

[0267] According to one embodiment, the processor (1130) may control a series of processes that enable the terminal to operate according to the embodiments of the present disclosure described above. For example, according to the embodiments of the present disclosure, the components of the terminal may be controlled to perform a transmission and reception method of the terminal by selecting one of an 'access carrier' and a 'data carrier'. There may be one or more processors (1130), and the processors (1130) 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 (1120).

[0268] The transceiver (1110) 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 (1110) 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-downconverts a received signal. However, the transceiver (1110) is only one embodiment, and the components of the transceiver (1110) are not limited to the RF transmitter and RF receiver. In addition, the transceiver (1110) can receive a signal through a wireless channel and output it to the processor (1130), and transmit a signal output from the processor (1130) through the wireless channel.

[0269] According to one embodiment, the memory (1120) can store programs and data necessary for the operation of the terminal. In addition, the memory (1120) can store control information or data included in signals transmitted and received by the terminal. The memory (1120) 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 number of memories (1120) can be plural. According to one embodiment, the memory (1120) can store a program for performing transmission and reception operations of the terminal depending on whether the target with which the terminal wants to communicate is an 'access carrier' or a 'data carrier', as in the embodiments of the present disclosure described above.

[0270] FIG. 12 is a block diagram showing an example of a configuration of a base station according to one embodiment of the present disclosure.

[0271] As illustrated in FIG. 12, the base station of the present disclosure may include a processor (1230), a transceiver (1210), and a memory (1220). 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 (1230), the transceiver (1210), and the memory (1220) may be implemented in the form of a single chip.

[0272] The processor (1230) 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 components of the base station may be controlled to perform a method for scheduling a terminal depending on whether an 'access carrier' or a 'data carrier' communicates with the terminal according to the embodiments of the present disclosure. There may be one or more processors (1230), and the processors (1230) may execute a program stored in the memory (1220) to perform a method for scheduling a terminal depending on whether the terminal communicates with the terminal through the 'access carrier' or the 'data carrier' of the present disclosure described above.

[0273] The transceiver (1210) can transmit and receive signals with the terminal. The signals transmitted and received with the terminal can include control information and data. The transceiver (1210) 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 (1210) is only one embodiment, and the components of the transceiver (1210) are not limited to the RF transmitter and RF receiver. In addition, the transceiver (1210) can receive a signal through a wireless channel and output it to the processor (1230), and transmit a signal output from the processor (1230) through the wireless channel.

[0274] According to one embodiment, the memory (1220) may store programs and data required for the operation of the base station. In addition, the memory (1220) may store control information or data included in signals transmitted and received by the base station. The memory (1220) 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 (1220). According to one embodiment, the memory (1220) may store a program for performing a method of scheduling a terminal depending on whether communication with the terminal is performed through an 'access carrier' or a 'data carrier', as in the embodiments of the present disclosure described above.

[0275] 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.

[0276] Meanwhile, the present specification and drawings disclose preferred embodiments of the present disclosure, and although specific terms are used, they are used in a general sense only 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 can be combined and operated as needed.

[0277] 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

In a method performed by a UE (user equipment) in a wireless communication system, A step of receiving system information from a base station on an access carrier; A step of transmitting a random access preamble on one or more data carriers based on the received system information; and A method comprising the step of receiving a random access response to the transmitted random access preamble on one of the one or more data carriers. In the first paragraph, A step of identifying the size of DCI (downlink control information) received on the access carrier based on the size of the maximum DL (downlink) bandwidth; and Further comprising a step of monitoring the DCI on the access carrier based on the size of the identified DCI, The above system information is, A method for scheduling by DCI received through the above monitoring. In the first paragraph, The data carrier from which the random access response is received is a data carrier among the one or more data carriers for which a switch-on condition is satisfied, The above switch-on conditions are: A method comprising at least one of: whether the channel quality status of each data carrier exceeds a first threshold; or whether the data rate required by the UE exceeds a second threshold. In the first paragraph, Based on the size of the DL (downlink) bandwidth of the data carrier for which the random access response is received, the size of the first frequency domain resource allocation control information for scheduling DL data of the data carrier is determined, A method in which the size of second frequency domain resource allocation control information for scheduling UL data of the data carrier is determined based on the size of the UL (uplink) bandwidth of the data carrier. In paragraph 4, When the size of the first DCI (downlink control information) for DL ​​data determined based on the size of the first frequency domain resource allocation control information and the size of the second DCI for UL data determined based on the size of the second frequency domain resource allocation control information are different: Zero padding is performed on the DCI having a smaller size among the first DCI and the second DCI so that the sizes of the first DCI and the second DCI are the same, or A method in which truncation is performed on a DCI having a larger size among the first DCI and the second DCI so that the sizes of the first DCI and the second DCI become the same. In a method performed by a base station in a wireless communication system, A step of transmitting system information to a UE (user equipment) on an access carrier; and A step of identifying a data carrier that satisfies a switch-on condition among one or more data carriers from which a random access preamble has been transmitted from the UE based on the transmitted system information, A method in which UL (uplink) data transmission or DL ​​(downlink) data reception of the UE is performed on the identified data carrier. In paragraph 6, A step of determining the size of DCI (downlink control information) transmitted on the access carrier based on the size of the maximum DL (downlink) bandwidth; and Further comprising a step of transmitting the DCI on the access carrier based on the size of the determined DCI, The above system information is, A method for scheduling by DCI received through the above monitoring. In the sixth paragraph, the switch-on condition is: A method comprising at least one of: whether the channel quality status of each data carrier exceeds a first threshold; or whether the data rate required by the UE exceeds a second threshold. In paragraph 6, The size of the first frequency domain resource allocation control information for scheduling DL data of the data carrier is determined based on the size of the DL (downlink) bandwidth of the data carrier to which the random access response for the random access preamble is transmitted, A method in which the size of second frequency domain resource allocation control information for scheduling UL data of the data carrier is determined based on the size of the UL (uplink) bandwidth of the data carrier. In paragraph 9, When the size of the first DCI for DL ​​data determined based on the size of the first frequency domain resource allocation control information and the size of the second DCI for UL data determined based on the size of the second frequency domain resource allocation control information are different: Zero padding is performed on the DCI having a smaller size among the first DCI and the second DCI so that the sizes of the first DCI and the second DCI are the same, or A method in which truncation is performed on a DCI having a larger size among the first DCI and the second DCI so that the sizes of the first DCI and the second DCI become the same. In a wireless communication system, in the UE (user equipment), Transmitter and receiver; and At least one processor communicatively coupled to the transceiver; and A memory communicatively coupled to at least one processor and storing one or more instructions, The one or more instructions, when individually or collectively executed by the at least one processor, cause the UE to: Receive system information from a base station on an access carrier, Based on the received system information, a random access preamble is transmitted on one or more data carriers, A UE configured to receive a random access response to the transmitted random access preamble from one of the one or more data carriers. In the 11th paragraph, the one or more commands, when individually or collectively executed by the at least one processor, cause the UE to further: Based on the size of the maximum DL (downlink) bandwidth, identify the size of the DCI (downlink control information) received on the access carrier, Based on the size of the identified DCI, the DCI is monitored on the access carrier, The above system information is, UE scheduled by DCI received through the above monitoring. In Article 11, The data carrier from which the random access response is received is a data carrier among the one or more data carriers for which a switch-on condition is satisfied, The above switch-on conditions are: A UE comprising at least one of: whether the channel quality status of each data carrier exceeds a first threshold; or whether the data rate required by the UE exceeds a second threshold. In Article 11, Based on the size of the DL (downlink) bandwidth of the data carrier for which the random access response is received, the size of the first frequency domain resource allocation control information for scheduling DL data of the data carrier is determined, A UE in which the size of second frequency domain resource allocation control information for scheduling UL data of the data carrier is determined based on the size of the UL (uplink) bandwidth of the data carrier. In a wireless communication system, at a base station, Transmitter and receiver; and At least one processor communicatively coupled to the transceiver; and A memory communicatively coupled to at least one processor and storing one or more instructions, The one or more instructions, when individually or collectively executed by the at least one processor, cause the base station to: Transmit system information to UE (user equipment) on an access carrier, Based on the transmitted system information, a data carrier satisfying a switch-on condition is identified among one or more data carriers from which a random access preamble has been transmitted from the UE, A base station where UL (uplink) data transmission or DL ​​(downlink) data reception of the UE is performed on the identified data carrier.

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