Method and device for energy saving in wireless communication system

Abstract

A method for a user equipment (UE), according to one embodiment, may comprise: receiving a signal from a base station through at least one reference resource; measuring energy consumption on the basis of the at least one reference resource; generating energy consumption related information of the UE on the basis of the measurement result; and transmitting the energy consumption related information of the UE to the base station.

Description

Method and device for energy saving in wireless communication systems

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a method and device for energy saving of a base station in a wireless communication system.

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

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

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

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

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

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

[0008] According to one embodiment, a method of a user equipment (UE) in a wireless communication system is provided. The method of the UE may include: receiving a signal from a base station via at least one reference resource; measuring energy consumption based on the at least one reference resource; generating information related to the energy consumption of the UE based on the measurement result; and transmitting the information related to the energy consumption of the UE to the base station.

[0009] According to one embodiment, information related to energy consumption of the UE may include information about a ratio of the amount of energy consumed upon reception of a signal through at least one reference resource to the amount of energy consumed upon reception of a reference signal.

[0010] According to one embodiment, information related to energy consumption of the UE may include one index value among a plurality of index values ​​defined to indicate energy consumption of the terminal.

[0011] According to one embodiment, the reference resource may include at least one of a channel state information-reference signal (CSI-RS), a synchronization signal block (SSB), a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), or a demodulation reference signal (DMRS).

[0012] According to one embodiment, information related to energy consumption of a UE may be generated based on energy consumption resulting from reception of a signal through one reference resource at the physical layer.

[0013] According to one embodiment, information related to energy consumption of a UE may be generated based on an average energy efficiency according to reception of signals through multiple reference resources in a higher layer.

[0014] According to one embodiment, the method of the UE may further include the step of receiving, from a base station, configuration information including transmission-related parameters determined based on information related to energy consumption of the UE or information on whether to perform a handover, determined based on information related to energy consumption of the UE.

[0015] According to one embodiment, the method of the UE may further include: receiving a plurality of transmission-related configuration information from a base station via radio resource control (RRC) signaling; and transmitting, to the base station, information related to energy consumption associated with at least one of the plurality of transmission-related configuration information.

[0016] According to one embodiment, the method of the UE may further include the step of transmitting, to the base station, transmission-related configuration information preferred by the UE based on information related to energy consumption associated with at least one of the plurality of transmission-related configuration information.

[0017] According to one embodiment, a method of a base station in a wireless communication system is provided. The method of the base station may include: transmitting a signal to a user equipment (UE) via at least one reference resource; receiving, from the UE, information related to energy consumption of the UE. The information related to energy consumption of the UE may be associated with energy consumption of the UE measured based on at least one reference resource. The method of the base station may include: determining transmission-related parameters or whether to perform a handover based on the information related to energy consumption of the UE; and transmitting, to the UE, configuration information including transmission-related parameters determined based on the information related to energy consumption of the UE or information related to whether to perform a handover based on the information related to energy consumption of the UE.

[0018] According to one embodiment, a user equipment (UE) is provided in a wireless communication system. The UE may include a memory storing a program or at least one instruction; and at least one processor. By executing the program or at least one instruction stored in the memory, either alone or in cooperation with each other, the UE may perform the following operations: the UE may receive a signal from a base station through at least one reference resource; measure energy consumption based on the at least one reference resource; generate information related to energy consumption of the UE based on the measurement result; and transmit information related to energy consumption of the UE to the base station.

[0019] According to one embodiment, information related to energy consumption of the UE may include information about a ratio of the amount of energy consumed upon reception of a signal through at least one reference resource to the amount of energy consumed upon reception of a reference signal.

[0020] According to one embodiment, information related to energy consumption of the UE may include one index value among a plurality of index values ​​defined to indicate energy consumption of the terminal.

[0021] According to one embodiment, the reference resource may include at least one of a channel state information-reference signal (CSI-RS), a synchronization signal block (SSB), a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), or a demodulation reference signal (DMRS).

[0022] According to one embodiment, a base station is provided in a wireless communication system. The base station may include a memory storing a program or at least one instruction; and at least one processor. By executing the program or at least one instruction stored in the memory by the at least one processor, either alone or in cooperation, the base station may perform the following operations: the base station may transmit a signal to a user equipment (UE) through at least one reference resource; receive information related to energy consumption of the UE from the UE; the information related to energy consumption of the UE is associated with an energy consumption amount of the UE measured based on at least one reference resource, and determine transmission-related parameters or whether to perform a handover based on the information related to energy consumption of the UE; and transmit configuration information including transmission-related parameters or information related to whether to perform a handover to the UE, determined based on the information related to energy consumption of the UE.

[0023] FIG. 1 is a diagram illustrating a basic structure of a time-frequency resource domain of a 5G system according to one embodiment of the present disclosure.

[0024] FIG. 2 is a diagram illustrating a time domain mapping structure and beam sweeping operation of a synchronization signal according to one embodiment of the present disclosure.

[0025] FIG. 3 is a diagram illustrating a random access procedure according to one embodiment of the present disclosure.

[0026] FIG. 4 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.

[0027] FIG. 5 is a diagram illustrating a control resource set (CORESET) as a time-frequency resource to which a PDCCH is mapped according to one embodiment of the present disclosure.

[0028] FIG. 6 is a diagram illustrating the mapping of DCI and DMRS in REG, which is a basic unit of a downlink control channel according to one embodiment of the present disclosure.

[0029] FIG. 7 is a diagram for explaining base station beam allocation according to TCI state setting according to one embodiment of the present disclosure.

[0030] FIG. 8 is a diagram illustrating a hierarchical signaling method for dynamic allocation of PDCCH beams of NR according to one embodiment of the present disclosure.

[0031] FIG. 9 is a diagram illustrating a TCI indication MAC CE signaling structure for PDCCH DMRS according to one embodiment of the present disclosure.

[0032] FIG. 10 is a diagram for explaining a method for a base station and a terminal to transmit and receive data by taking into account downlink data channels and rate matching resources according to one embodiment of the present disclosure.

[0033] FIG. 11 is a diagram for explaining a method for a terminal to report aperiodic CSI when the CSI-RS offset is 0 according to one embodiment of the present disclosure.

[0034] FIG. 12 is a diagram for explaining a method for a terminal to report aperiodic CSI when the CSI-RS offset is 1 according to one embodiment of the present disclosure.

[0035] FIG. 13 is a diagram for explaining settings for a bandwidth part in a 5G communication system according to one embodiment of the present disclosure.

[0036] FIG. 14 is a diagram for explaining DRX (Discontinuous Reception) in a 5G communication system according to one embodiment of the present disclosure.

[0037] FIG. 15 is a drawing for explaining an energy saving method according to one embodiment of the present disclosure.

[0038] FIG. 16 is a diagram for explaining a method for a terminal to perform handover to another base station based on link quality and energy consumption according to one embodiment of the present disclosure.

[0039] FIG. 17 is a diagram for explaining a method for a terminal to report an EQI that measures energy consumption based on physical resources according to one embodiment of the present disclosure.

[0040] Figure 18 is a diagram for explaining a downlink L3-based handover operation based on EQI.

[0041] FIG. 19 is a diagram for explaining energy-related measurements measured and reported by a terminal according to one embodiment of the present disclosure for searching for surrounding base stations.

[0042] FIG. 20 is a diagram for explaining the transmission timing and configuration update when a terminal transmits EQI for CSI purposes according to one embodiment of the present disclosure.

[0043] FIG. 21 is a diagram illustrating the operation of a terminal according to one embodiment of the present disclosure for maintaining an energy efficiency level when EQI operates for CSI purposes.

[0044] FIG. 22 is a block diagram illustrating a terminal transceiver device according to one embodiment of the present disclosure.

[0045] FIG. 23 is a block diagram illustrating components of a terminal according to one embodiment of the present disclosure.

[0046] FIG. 24 is a block diagram illustrating components of a base station according to one embodiment of the present disclosure.

[0047] 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.

[0048] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to ensure that the 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.

[0049] 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).

[0050] 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.

[0051] 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.

[0052] Additionally, the description 'at least one of A, B, and C' means that it can be any one of 'A', 'B', 'C', 'A and B', 'A and C', 'B and C', and 'A, B, and C'.

[0053] It should be understood that the combinations of blocks and sequence diagrams in each flowchart can be performed by one or more computer programs containing computer-executable instructions. The one or more computer programs may be stored entirely in a single memory or may be divided and stored in multiple different memories.

[0054] All functions or operations described in this document may be performed by a single processor or a combination of processors. A single processor or a combination of processors is a circuitry that performs processing, and may include circuitry such as an Application Processor (AP), a Communication Processor (CP), a Graphical Processing Unit (GPU), a Neural Processing Unit (NPU), a Microprocessor Unit (MPU), a System on Chip (SoC), or an Integrated Chip (IC).

[0055] A processor may include various processing circuits and / or multiple processors. For example, the term “processor” as used herein, including in the claims, may include various processing circuits, including at least one processor. At least one processor, one or more processors, may be individually and / or collectively configured to perform the various functions described herein in a distributed fashion. As used herein, “processor,” “at least one processor,” and “one or more processors” may be configured to perform multiple functions. However, these terms encompass, without limitation, situations where one processor performs some of the functions and other processor(s) perform other parts of the functions, and situations where a single processor may perform all of the functions. Furthermore, the at least one processor may include a combination of processors that perform various of the disclosed functions in a distributed manner. At least one processor may execute program instructions to achieve or perform various functions.

[0056] 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. Embodiments of the present disclosure will be described below with reference to the accompanying drawings. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts unrelated to the description have been omitted for clarity in describing the present invention, and similar reference numerals have been used throughout the specification to designate similar parts.

[0057] 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.

[0058] 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."

[0059] 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).

[0060] 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. Furthermore, the term "terminal" can refer to not only mobile phones, smartphones, IoT devices, and sensors, but also other wireless communication devices.

[0061] Hereinafter, a base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, a gNB, an eNode B, an eNB, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. Of course, the present invention is not limited to the above examples.

[0062] To handle the explosive growth in mobile data traffic, 5G (5G), the next-generation communication system after LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)) and LTE-A (LTE-Advanced or E-UTRA Evolution), is being developed. thThe initial standards for the 5G (New Radio Access Technology Generation) system or New Radio access technology (NR) have been completed. While existing mobile communication systems have focused on conventional voice / data communications, the 5G system aims to satisfy various services and requirements, such as enhanced Mobile Broadband (eMBB) services to improve existing voice / data communications, Ultra-Reliable and Low Latency Communication (URLLC) services to support high-reliability / ultra-low latency communications, and massive Machine Type Communication (MTC) services to support massive machine-to-machine communications.

[0063] While the transmission bandwidth of existing LTE and LTE-A systems 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 as candidate frequencies, where securing ultra-wide bandwidth frequencies is relatively easy. 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.

[0064] Radio waves in the ultra-high frequency band are sometimes called millimeter waves (mmWave) because their wavelengths are on the order of millimeters. However, in the ultra-high frequency band, the path loss of radio waves increases in proportion to the frequency band, reducing the coverage of mobile communication systems.

[0065] In order to overcome the disadvantage of reduced coverage in the above ultra-high frequency band, beamforming technology can be applied, which uses multiple antennas to concentrate the radiated energy of radio waves to a predetermined target point and increase the transmission distance of radio waves. That is, the beam width of the signal to which the beamforming technology is applied becomes relatively narrow, and the radiated energy is concentrated within the narrowed beam width, thereby increasing the transmission distance. The beamforming technology can be applied to both the transmitter and the receiver. In addition to the effect of increasing coverage, the beamforming technology has the effect of reducing interference in areas other than the beamforming direction. In order for the beamforming technology to operate properly, accurate measurement and feedback methods of the transmission / reception beams are required. The beamforming technology can be applied to a control channel or a data channel that corresponds one-to-one between a predetermined terminal and a base station. Additionally, beamforming technology can be applied to common signals transmitted by a base station to multiple terminals within a system, such as synchronization signals, physical broadcast channels (PBCH), control channels for transmitting system information, and data channels, to increase coverage. When beamforming technology is applied to common signals, beam sweeping technology, which transmits signals by changing the beam direction, is additionally applied so that the common signal can reach terminals located at any location within the cell.

[0066] Another requirement for 5G systems is ultra-low latency services, with transmission delays of approximately 1 ms 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 used for scheduling, and the TTI of existing LTE and LTE-A systems is 1 ms, which corresponds to the length of one subframe. For example, to meet the requirements for ultra-low latency services in the 5G system, possible short TTIs are 0.5 ms, 0.25 ms, and 0.125 ms, which are shorter than those of existing LTE and LTE-A systems.

[0067] FIG. 1 is a diagram illustrating a basic structure of a time-frequency resource domain of a 5G system according to one embodiment of the present disclosure.

[0068] That is, FIG. 1 is a diagram showing the basic structure of a time-frequency resource area, which is a radio resource area in which data or control channels of a 5G system are transmitted.

[0069] 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. (102) symbols are grouped together to form one slot (106), A plurality of slots can be gathered to form a subframe (105). The length of the subframe 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 the total It can be composed of (104) subcarriers.

[0070] 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. It can be defined as (110) consecutive subcarriers. In 5G systems, =12, and the data rate can increase in proportion to the number of RBs scheduled to the terminal.

[0071] In a 5G system, a base station maps data in RB units, and scheduling can be performed for 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.

[0072] 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 can be. Extended CP can be applied to a system with a relatively long transmission distance than the general CP, so that orthogonality between symbols can be maintained. In the case of the general CP, since the ratio of the CP length to the symbol length is maintained at a constant value, the overhead due to the 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.

[0073] In 5G systems, various frame structures can be supported by adjusting the subcarrier spacing to meet diverse services and requirements. For example,

[0074] - 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.

[0075] - 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.

[0076] - 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.

[0077] The above subcarrier spacing, CP length, etc. are essential information for OFDM transmission and reception. The base station and the terminal must recognize the subcarrier spacing, CP length, etc. as common values ​​to enable smooth transmission and reception. [Table 1] shows the subcarrier spacing configuration supported by the 5G system. ), subcarrier spacing ( ), which represents the relationship between CP length.

[0078] [Table 1]

[0079]

[0080] [Table 2] shows the subcarrier spacing settings for the general CP ( ) not much, each with a different number of symbols per slot ( ), number of slots per frame ( ), number of slots per subframe ( ) is indicated.

[0081] [Table 2]

[0082]

[0083] [Table 3] shows the subcarrier spacing settings for extended CP ( ) not much, each with a different number of symbols per slot ( ), number of slots per frame ( ), number of slots per subframe ( ) is indicated.

[0084] [Table 3]

[0085]

[0086] In the early stages of 5G system deployment, coexistence or dual-mode operation with existing LTE and / or LTE-A (hereinafter referred to as LTE / LTE-A) systems is expected. This allows existing LTE / LTE-A to provide stable system operation to terminals, while the 5G system can provide enhanced services to these 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).

[0087] For example, setting the subcarrier spacing In-frame structure (hereinafter referred to as frame structure A) and subcarrier spacing settings Comparing the in-frame structure (hereinafter referred to as frame structure B), compared to frame structure A, frame structure B has a subcarrier spacing and RB size that are twice as large, and a slot length and symbol length that are twice as small. In the case of frame structure B, two slots can be configured into one subframe, and 20 subframes can be configured into one frame.

[0088] Generalizing the frame structure of the above 5G system provides high scalability by ensuring that essential parameter sets, such as 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.

[0089] The above frame structure can be applied to correspond to various scenarios. From a cell size perspective, since a longer CP length can support a larger cell, the frame structure A can support a relatively larger cell than the frame structure B. From an operating frequency band perspective, since a larger subcarrier spacing is advantageous for phase noise recovery in a high-frequency band, the frame structure B can support a relatively higher operating frequency than the frame structure A. From a service perspective, since a shorter slot length, which is a basic time unit of scheduling, is advantageous for supporting an ultra-low delay service such as URLLC, the frame structure B can be relatively more suitable for the URLLC service than the frame structure A.

[0090] 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.

[0091] In the initial access stage where a terminal first accesses the system, the terminal can synchronize downlink time and frequency from a synchronization signal transmitted by a base station through cell search, and obtain a cell identifier (cell ID). 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.

[0092] A synchronization signal is a signal that serves as a reference for cell search, and subcarrier spacing can be applied to suit channel environments such as phase noise for each frequency band. In the case of a data channel or control channel, as described above, different subcarrier spacings can be applied depending on the service type in order to support various services.

[0093] FIG. 2 is a diagram illustrating a time domain mapping structure and beam sweeping operation of a synchronization signal according to one embodiment of the present disclosure.

[0094] For the purpose of explanation, the following components can be defined:

[0095] - PSS (Primary Synchronization Signal): This signal serves as the basis for DL ​​time / frequency synchronization and provides some cell ID information.

[0096] - SSS (Secondary Synchronization Signal): Serves as a reference for DL ​​time / frequency synchronization and provides some remaining information, including the cell ID. Additionally, it can serve as a reference signal for PBCH demodulation.

[0097] - PBCH (Physical Broadcast Channel): Provides MIB (Master Information Block), which is essential system information required for transmission and reception of data channels and control channels of the terminal. The essential system information may include search space-related control information indicating radio resource mapping information of the control channel, scheduling control information for a separate data channel that transmits system information, and SFN (System Frame Number), which is a frame-unit index that serves as a timing reference.

[0098] - SS / PBCH Block (Synchronization Signal / PBCH Block or SSB): An SS / PBCH block consists of N OFDM symbols and is a combination of PSS, SSS, PBCH, etc. In a system where beam sweeping technology is applied, the SS / PBCH block is the minimum unit to which beam sweeping is applied. In a 5G system, N can be 4. The base station can transmit up to L SS / PBCH blocks, and the L SS / PBCH blocks are mapped within a half frame (0.5 ms). In addition, the L SS / PBCH blocks are periodically repeated in units of a predetermined period P. The period P can be notified to the terminal by the base station through signaling. If there is no separate signaling for the period P, the terminal applies a pre-agreed default value.

[0099] FIG. 2 illustrates an example in which beam sweeping is applied to SS / PBCH block units over time. Referring to FIG. 2, terminal 1 (205) receives an SS / PBCH block using a beam radiated in the direction of #d0 (203) by beamforming applied to SS / PBCH block #0 at time t1 (201). Terminal 2 (206) receives an SS / PBCH block using a beam radiated in the direction of #d4 (204) by beamforming applied to SS / PBCH block #4 at time t2 (202). The terminal can obtain an optimal synchronization signal through a beam radiated from the base station in the direction where the terminal is located. For example, terminal 1 (205) may have difficulty in obtaining time / frequency synchronization and essential system information from an SS / PBCH block through a beam radiated in the direction of #d4, which is far from the location of terminal 1.

[0100] In addition to the initial connection procedure described above, the terminal may also receive SS / PBCH blocks to determine whether the radio link quality of the current cell is maintained at a certain level or higher. Furthermore, during a handover procedure in which the terminal moves from the current cell to a neighboring cell, the terminal may receive SS / PBCH blocks from the neighboring cell to determine the radio link quality of the neighboring cell and obtain time / frequency synchronization with the neighboring cell.

[0101] 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 a 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. 3.

[0102] FIG. 3 illustrates a random access procedure according to one embodiment of the present disclosure.

[0103] FIG. 3 is only an example of a random access procedure, and the present disclosure is not limited thereto. In addition, the present disclosure is not limited to the 4-step random access procedure illustrated in FIG. 3, and can also be applied to a 2-step random access procedure (transmitting and receiving message A (a message including information corresponding to message 1 and message 3)) and message B (a message including information corresponding to message 2 and message 4)).

[0104] Referring to FIG. 3, as a first step (310) of the random access procedure, the terminal (301) transmits a random access preamble to the base station (302). 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.

[0105] The base station can measure the transmission delay 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 provided in advance through system information.

[0106] The initial transmission power of the random access preamble can be determined based on the path loss between the base station and the terminal as measured by the terminal.

[0107] The terminal can transmit the random access preamble by determining the transmission beam direction of the random access preamble from the synchronization signal received from the base station.

[0108] In the second step (320), the base station (302) transmits an uplink transmission timing adjustment command (message 2) to the terminal (301) based on the transmission delay value measured from the random access preamble received in the first step (310). In addition, the base station may transmit an uplink resource and power control command to be used by the terminal as scheduling information. The scheduling information may include control information for the terminal's uplink transmission beam.

[0109] If the terminal does not receive a random access response (RAR) or uplink transmission timing adjustment command (message 2), which is scheduling information for message 3 in the second step (320), from the base station within a predetermined time, the first step (310) can be performed again.

[0110] If the terminal proceeds with the first step (310) again, the terminal can increase the probability of the base station receiving the random access preamble by increasing the transmission power of the random access preamble by a predetermined step and transmitting it (power ramping).

[0111] In the third step (330), the terminal (301) transmits uplink data (message 3) including its terminal ID to the base station (302) through an uplink data channel (Physical Uplink Shared Channel, PUSCH) using the uplink resources allocated in the second step (320). 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 (320).

[0112] 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 (320) and the power ramping value of the random access preamble. The uplink data channel for transmitting Message 3 may refer to the first uplink data signal transmitted by the terminal to the base station after the terminal transmits the random access preamble.

[0113] In the fourth step (340), if the base station (302) determines that the terminal has performed random access without collision with another terminal, it transmits data (message 4) including the ID of the terminal that transmitted uplink data in the third step (330) to the terminal (301).

[0114] When the terminal receives a signal transmitted by the base station in step 4 (340), it can determine that random access is successful.

[0115] The terminal can transmit HARQ-ACK information indicating whether message 4 was successfully received to the base station through an uplink control channel (Physical Uplink Control Channel, PUCCH).

[0116] If the data transmitted by the terminal in step 3 (330) collides with data from another terminal, causing the base station to fail to receive a data signal from the terminal, the base station may not transmit any more data to the terminal. If the terminal fails to receive the data transmitted from the base station in step 4 (340) within a certain period of time, the random access procedure may be determined to have failed, and the process may be restarted from step 1 (310).

[0117] 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 by referencing the UE capability information of the terminal. Through the UE capability information, the terminal can inform the base station whether it supports a certain function, the maximum allowable value of the function supported by the terminal, etc. Therefore, the UE capability information reported by each terminal to the base station may have different values ​​for each terminal.

[0118] For example, the terminal may report UE capability information including at least a portion of the following control information as the UE capability information to the base station.

[0119] - Control information related to frequency bands supported by the terminal

[0120] - Control information related to channel bandwidth supported by the terminal

[0121] - Control information related to the maximum modulation method supported by the terminal

[0122] - Control information related to the maximum number of beams supported by the terminal

[0123] - Control information related to the maximum number of layers supported by the terminal

[0124] - Control information related to CSI reporting supported by the terminal

[0125] - Control information on whether the terminal supports frequency hopping

[0126] - Bandwidth-related control information when supporting carrier aggregation (CA)

[0127] - Control information on whether cross carrier scheduling is supported when carrier aggregation is supported.

[0128] FIG. 4 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.

[0129] Referring to FIG. 4, at step 410, the base station (402) can transmit a UE capability information request message to the terminal (401). In response to the base station's request for UE capability information, the terminal transmits UE capability information to the base station at step 420.

[0130] Through the above process, terminals connected to the base station are placed in the RRC_CONNECTED state, enabling one-to-one communication. Conversely, terminals that are not connected are placed in the RRC_IDLE state. The operations of terminals in this state are divided as follows.

[0131] - Operates terminal-specific DRX (Discontinuous Reception) cycle set by upper layer

[0132] - Action to receive paging messages from the core network

[0133] - Obtain system information

[0134] - Measurement operations related to surrounding cells and cell reselection

[0135] In 5G systems, a new terminal state called RRC_INACTIVE has been defined to reduce the energy and time consumed during initial access. In addition to the actions performed by RRC_IDLE terminals, RRC_INACTIVE terminals perform the following actions:

[0136] - Storage of AS (Access stratum) information required for cell access

[0137] - Terminal-specific DRX cycle operation set by the RRC layer

[0138] - Setting up and periodically updating an RNA (RAN-based notification area) that can be used during handover by the RRC layer.

[0139] - Monitoring RAN-based paging messages transmitted via I-RNTI

[0140] Below, a scheduling method is described in which a base station transmits downlink data to a terminal or instructs the terminal to transmit uplink data.

[0141] Downlink Control Information (DCI) is control information transmitted from a base station to a terminal via the downlink. It may include downlink data scheduling information or uplink data scheduling information for a given terminal. Typically, the base station independently channel-codes DCI for each terminal and then transmits it to each terminal via the Physical Downlink Control Channel (PDCCH).

[0142] The base station can operate by applying a predetermined DCI format according to the purpose, such as whether it is scheduling information for downlink data (downlink assignment) for the terminal to be scheduled, whether it is scheduling information for uplink data (uplink grant), and whether it is DCI for power control.

[0143] 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 provided by the base station to the terminal via DCI related to downlink data scheduling information among the DCIs transmitted via the PDCCH.

[0144] 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.

[0145] FIG. 5 is a diagram illustrating a control resource set (CORESET) as a time-frequency resource to which a PDCCH is mapped according to one embodiment of the present disclosure.

[0146] Referring to FIG. 5, two control resource sets (Control Resource Set #1 (501), Control Resource Set #2 (502)) can be set within a UE bandwidth part (510) along the frequency axis and within one slot (520) along the time axis. The Control Resource Sets (501, 502) can be set to specific frequency resources (503) within the entire UE bandwidth part (510) along the frequency axis. The Time Axis can be set to one or more OFDM symbols, and this can be defined as the Control Resource Set Duration (504).

[0147] Control resource set #1 (501) can be set to a control resource set length of 2 symbols, and control resource set #2 (502) can be set to a control resource set length of 1 symbol.

[0148] A base station can configure one or more CORESETs for a terminal through higher layer signaling (e.g., system information, MIB (Master Information Block), RRC (Radio Resource Control) signaling). Configuring a CORESET for a terminal may mean providing information such as a CORESET identifier, the frequency location of the CORESET, and the symbol length of the CORESET. The information that the base station provides to the terminal to configure a CORESET may include at least some of the information included in [Table 4].

[0149] [Table 4]

[0150]

[0151] CORESET is in the frequency domain It can be composed of RBs and in the time domain It can be composed of symbols. The NR PDCCH can be composed of one or more CCEs (Control Channel Elements). One CCE can be composed of six REGs (Resource Element Groups), and a REG can be defined as one RB during one OFDM symbol. Within one CORESET, REGs can be indexed in time-first order, starting with REG index 0 from the first OFDM symbol of the CORESET, the lowest RB.

[0152] 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 [Table 5] below.

[0153] [Table 5]

[0154]

[0155] 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.

[0156] FIG. 6 is a diagram illustrating the mapping of DCI and DMRS in REG, which is a basic unit of a downlink control channel according to one embodiment of the present disclosure.

[0157] Referring to FIG. 6, the basic unit of the downlink control channel, i.e., the resource element group (REG) (603), may include both REs to which DCI is mapped and areas to which DMRS (605), which is a reference signal for decoding the REs, is mapped. In addition, three DMRSs (605) may be transmitted within one REG (603).

[0158] Hereinafter, the search space of the PDCCH is described. The number of control channel elements (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, one downlink control channel can be transmitted through L CCEs. The terminal performs blind decoding to detect a signal without knowing information about the downlink control channel, and for this purpose, a search space representing a set of CCEs can be defined.

[0159] A search space is a set of downlink control channel candidates (CCEs) that a terminal must attempt to decode at a given aggregation level. Since there are multiple aggregation levels, each of which can be a set of 1, 2, 4, 8, or 16 CCEs, a terminal can have multiple search spaces. A search space set can be defined as the set of search spaces at all configured aggregation levels.

[0160] The search space can be divided into a common search space (CSS) and a UE-specific search space (USS). A certain group of UEs, or all UEs, can search 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.

[0161] For example, a terminal can receive scheduling allocation information for a PDSCH for receiving system information by examining a common search space of a PDCCH. In the case of a common search space, since a certain group of terminals or all terminals must receive the PDCCH, it can be defined as a set of pre-arranged CCEs. Terminal-specific scheduling allocation information for a PDSCH or PUSCH can be received by the terminal by examining a terminal-specific search space of the PDCCH. The terminal-specific search space can be defined terminal-specifically as a function of the terminal's ID and various system parameters.

[0162] 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 [Table 6].

[0163] [Table 6]

[0164]

[0165]

[0166]

[0167] 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.

[0168] 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.

[0169] 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.

[0170] - 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

[0171] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0172] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0173] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0174] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0175] - DCI format 2_4 with CRC scrambled by CI-RNTI

[0176] - DCI format 2_5 with CRC scrambled by AI-RNTI

[0177] - DCI format 2_6 with CRC scrambled by PS-RNTI

[0178] - DCI format 2_7 with CRC scrambled by PEI-RNTI

[0179] In a terminal-specific search space, a terminal may monitor the following combinations of DCI formats and RNTIs, but is not limited thereto.

[0180] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0181] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0182] The above RNTIs may follow the following definitions and uses:

[0183] C-RNTI (Cell RNTI): For terminal-specific PDSCH or PUSCH scheduling purposes.

[0184] TC-RNTI (Temporary Cell RNTI): For terminal-specific PDSCH scheduling purposes

[0185] CS-RNTI (Configured Scheduling RNTI): Used for semi-statically configured terminal-specific PDSCH scheduling.

[0186] RA-RNTI (Random Access RNTI): Used for PDSCH scheduling in the random access phase.

[0187] P-RNTI (Paging RNTI): Used for scheduling PDSCH where paging is transmitted.

[0188] SI-RNTI (System Information RNTI): Used for scheduling PDSCH where system information is transmitted.

[0189] INT-RNTI (Interruption RNTI): Used to indicate whether pucturing is in progress for PDSCH.

[0190] TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to indicate power control commands for PUSCH.

[0191] TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to indicate power control commands for PUCCH.

[0192] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to indicate power control commands for SRS.

[0193] The DCI formats described above can follow the definitions shown in [Table 7] below.

[0194] [Table 7]

[0195]

[0196] CORESET p, the search space of aggregation level L in the search space set s can be expressed as the following mathematical formula.

[0197]

[0198] In the case of a terminal-specific search space, the value may correspond to a value that changes depending on the terminal's ID (C-RNTI or ID set to the terminal by the base station) and the time index.

[0199] Below, we will specifically describe how to set the TCI state for PDCCH (or PDCCH DMRS) in a 5G communication system.

[0200] The base station can set and indicate the TCI state for the PDCCH (or PDCCH DMRS) through appropriate signaling. According to the above description, the base station can set and indicate the TCI state for the PDCCH (or PDCCH DMRS) through appropriate signaling. The TCI state is to notify the QCL (Quasi co-location) relationship between the PDCCH (or PDCCH DMRS) and other RSs or channels. When a certain reference antenna port A (reference RS #A) and another target antenna port B (target RS #B) are QCLed with each other, it means that the terminal is allowed to apply some or all of the large-scale channel parameters estimated at the antenna port A to the channel measurement from the antenna port B. QCL may need to relate different parameters depending on the situation, such as 1) time tracking affected by average delay and delay spread, 2) frequency tracking affected by Doppler shift and Doppler spread, 3) radio resource management (RRM) affected by average gain, and 4) beam management (BM) affected by spatial parameters. Accordingly, NR supports four types of QCL relationships, as shown in Table 8 below.

[0201] [Table 8]

[0202]

[0203] The above spatial RX parameter may collectively refer to some or all of various parameters, such as Angle of arrival (AoA), Power Angular Spectrum (PAS) of AoA, Angle of departure (AoD), PAS of AoD, transmit / receive channel correlation, transmit / receive beamforming, and spatial channel correlation.

[0204] The above QCL relationship can be set to the terminal through the RRC parameters TCI-State and QCL-Info as shown in Table 9 below. Referring to Table 9, the base station can set one or more TCI states to the terminal and inform the RS referencing the ID of the TCI state, i.e., up to two QCL relationships (qcl-Type1, qcl-Type2) for the target RS. At this time, each QCL information (QCL-Info) included in the above TCI state includes the serving cell index and BWP index of the reference RS indicated by the corresponding QCL information, the type and ID of the reference RS, and the QCL type as shown in Table 8 above.

[0205] [Table 9]

[0206]

[0207] FIG. 7 is a diagram for explaining base station beam allocation according to TCI state setting according to one embodiment of the present disclosure.

[0208] Referring to FIG. 7, the base station can transmit information about N different beams to the terminal through N different TCI states.

[0209] For example, when N=3, the base station can notify that the antenna ports referencing different TCI states 700, 705, or 710 have different spatial Rx parameters, i.e., are associated with different beams, by having the qcl-Type2 parameters included in the three TCI states (700, 705, 710) be associated with CSI-RS or SSB corresponding to different beams and set to QCL type D.

[0210] Specifically, the TCI state combinations applicable to the PDCCH DMRS antenna port are as shown in Table 10 below. The fourth row in Table 10 is the combination assumed by the terminal before RRC configuration, and configuration after RRC is not possible.

[0211] [Table 10]

[0212]

[0213] NR supports a hierarchical signaling method as illustrated in FIG. 8 for dynamic allocation of PDCCH beams.

[0214] FIG. 8 is a diagram illustrating a hierarchical signaling method for dynamic allocation of PDCCH beams of NR according to one embodiment of the present disclosure.

[0215] Referring to FIG. 8, the base station can set N TCI states (805, 810, ..., 820) to the terminal via RRC signaling (800), and can set some of them as TCI states for CORESET (825). Thereafter, the base station can indicate one of the TCI states (830, 835, 840) for CORESET to the terminal via MAC CE signaling (845). Thereafter, the terminal receives the PDCCH based on the beam information included in the TCI state indicated by the MAC CE signaling.

[0216] FIG. 9 is a diagram illustrating a TCI indication MAC CE signaling structure for PDCCH DMRS according to one embodiment of the present disclosure.

[0217] Referring to FIG. 9, the TCI indication MAC CE signaling for the PDCCH DMRS consists of 2 bytes (16 bits) and includes 1 bit of reserved bit (910), 5 bits of serving cell ID (915), 2 bits of BWP ID (920), 2 bits of CORESET ID (925), and 6 bits of TCI state ID (930).

[0218] A base station can indicate one of the TCI state lists included in the CORESET configuration via MAC CE signaling. Until another TCI state is indicated to the corresponding CORESET via another MAC CE signaling, the terminal assumes that the same QCL information applies to all one or more search spaces connected to the CORESET.

[0219] The PDCCH beam allocation method described above has the disadvantage that it is difficult to instruct a beam change faster than the MAC CE signaling delay, and that the same beam is applied to all CORESETs regardless of search space characteristics, making flexible PDCCH beam operation difficult.

[0220] The embodiments of the present disclosure below provide a more flexible PDCCH beam configuration and operation method. While several distinct examples are provided for convenience in describing the embodiments of the present disclosure below, they are not mutually exclusive and can be appropriately combined and applied depending on the situation.

[0221] A base station can set one or more TCI states for a specific control resource set to a terminal, and can activate one of the set TCI states through a MAC CE activation command.

[0222] For example, if {TCI state#0, TCI state#1, TCI state#2} is set as the TCI state for control resource set#1, the base station can transmit a command to the terminal to activate the terminal to assume TCI state#0 as the TCI state for control resource set#1 through MAC CE.

[0223] The terminal can correctly receive the DMRS of the corresponding control resource set based on the QCL information within the activated TCI state, based on the activation command for the TCI state received by the MAC CE.

[0224] For a control resource set (control resource set #0) with an index set to 0, if the terminal has not received a MAC CE activation command for the TCI state of control resource set #0, the terminal can assume that the DMRS transmitted in control resource set #0 has been QCL'd with the SS / PBCH block identified during the initial access process or the non-contention-based random access process that is not triggered by a PDCCH command.

[0225] For a control resource set (control resource set #X) whose index is set to a value other than 0, if the terminal has not set a TCI state for the control resource set #X, or has set one or more TCI states but has not received a MAC CE activation command to activate one of them, the terminal may assume that the DMRS transmitted in the control resource set #X is QCL'd with the SS / PBCH block identified during the initial access process.

[0226] Next, we will specifically explain downlink control information (DCI) in the 5G system.

[0227] 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 defined between the base station and the terminal, and the non-fallback DCI format can include configurable fields.

[0228] 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 determine that the message was transmitted to the UE.

[0229] 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).

[0230] DCI format 0_0 can be used as a fallback DCI for scheduling PUSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 0_0 with the CRC scrambled with C-RNTI can include the following information, for example, as shown in Table 11.

[0231] [Table 11]

[0232]

[0233]

[0234] DCI format 0_1 ​​can be used as a fallback DCI for scheduling PUSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 0_1 ​​with the CRC scrambled with C-RNTI can include the following information, for example, as shown in Table 12.

[0235] [Table 12]

[0236]

[0237]

[0238]

[0239]

[0240]

[0241]

[0242] DCI format 1_0 can be used as a fallback DCI for scheduling PDSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 1_0 with the CRC scrambled with C-RNTI can include the following information, for example, as shown in Table 13.

[0243] [Table 13]

[0244]

[0245]

[0246] DCI format 1_1 can be used as a fallback DCI for scheduling PDSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 1_1 with the CRC scrambled with C-RNTI can include the following information, for example, as shown in Table 14.

[0247] [Table 14]

[0248]

[0249]

[0250]

[0251]

[0252] Below, a time domain resource allocation method for a data channel in a 5G communication system is described.

[0253] The base station can set up a table for time domain resource allocation information for the downlink data channel (Physical Downlink Shared Channel; PDSCH) and the uplink data channel (Physical Uplink Shared Channel; PUSCH) to the terminal through higher layer signaling (e.g., RRC signaling). For the PDSCH, a table consisting of up to maxNrofDL-Allocations=16 entries can be set up, and for the PUSCH, a table consisting of up to maxNrofUL-Allocations=16 entries can be set up. For example, the time domain resource allocation information may include PDCCH-to-PDSCH slot timing (the time interval in slot units between the time point at which a PDCCH is received and the time point at which a PDSCH scheduled by the received PDCCH is transmitted, denoted as K0) or PDCCH-to-PUSCH slot timing (the time interval in slot units between the time point at which a PDCCH is received and the time point at which a PUSCH scheduled by the received PDCCH is transmitted, denoted as K2), information on the position and length of the start symbol for which a PDSCH or PUSCH is scheduled within a slot, the mapping type of the PDSCH or PUSCH, etc. For example, information such as those in Tables 15 and 16 below may be notified from the base station to the terminal.

[0254] [Table 15]

[0255]

[0256] [Table 16]

[0257]

[0258] The base station can notify the terminal of one of the entries in the table for the above time domain resource allocation information via L1 signaling (e.g., DCI) (e.g., by indicating it with the 'Time Domain Resource Allocation' field in the DCI). The terminal can obtain time domain resource allocation information for the PDSCH or PUSCH based on the DCI received from the base station.

[0259] Below, a method for allocating frequency domain resources for data channels in a 5G communication system is described.

[0260] In 5G, two types of methods for indicating frequency domain resource allocation information for downlink data channels (Physical Downlink Shared Channel; PDSCH) and uplink data channels (Physical Uplink Shared Channel; PUSCH) are supported: Resource Allocation Type 0 and Resource Allocation Type 1.

[0261] Resource Allocation Type 0

[0262] RB allocation information can be notified from the base station to the terminal in the form of a bitmap for an RBG (Resource Block Group). At this time, the RBG can be composed of a set of consecutive VRBs (Virtual RBs), and the size P of the RBG can be determined based on a value set as a higher layer parameter (rbg-Size) and the size value of the bandwidth part defined in Table 17 below.

[0263] [Table 17]

[0264]

[0265] - Size The total number of RBGs in bandwidth part i ( ) can be defined as follows.

[0266]

[0267] - Each bit in the bitmap of bit size can correspond to each RBG. RBGs can be indexed in order of increasing frequency starting from the lowest frequency position in the bandwidth part. Within the bandwidth part For the RBGs of the dog, from RBG#0 to RBG#( -1) can be mapped from MSB to LSB of the RBG bitmap. If a specific bit value in the bitmap is 1, the terminal can determine that the RBG corresponding to the bit value is allocated, and if a specific bit value in the bitmap is 0, the terminal can determine that the RBG corresponding to the bit value is not allocated.

[0268] Resource Allocation Type 1

[0269] - RB allocation information can be notified from the base station to the terminal as information on the starting position and length of consecutively allocated VRBs. At this time, interleaving or non-interleaving can be additionally applied to consecutively allocated VRBs. The resource allocation field of resource allocation type 1 can be composed of a resource indication value (RIV), and the RIV indicates the starting point of the VRB ( ) and the length of the consecutively allocated RB ( ) can be composed of. More specifically, RIV within the bandwidth part of the size can be defined as follows.

[0270]

[0271] For the purpose of supporting non-grant-based transmission and reception for a downlink data channel (Physical Downlink Shared Channel; PDSCH) or an uplink data channel (Physical Uplink Shared Channel; PUSCH) to a terminal, a base station can semi-statically set time and frequency transmission resources and various transmission and reception parameters for PDSCH and PUSCH.

[0272] To be more specific, it is as follows:

[0273] For the purpose of supporting downlink (DL) SPS (Semi-Persistent Scheduling) to a terminal, the base station can set the following information as shown in Table 18 through upper layer signaling (e.g. RRC signaling).

[0274] [Table 18]

[0275]

[0276] DL SPS can be set in a primary cell or a secondary cell, and DL SPS can be set in one cell within one cell group.

[0277] In 5G, two types of non-grant (also called Configured Grant, Grant free, etc.)-based transmission methods for uplink data channels (Physical Uplink Shared Channel; PUSCH) can be supported: Type-1 non-grant-based PUSCH transmission with a configured grant and Type-2 non-grant-based PUSCH transmission with a configured grant.

[0278] Non-acknowledgement-based PUSCH transmission type-1

[0279] In non-grant-based PUSCH transmission type-1, the base station can set specific time / frequency resources (600) that allow non-grant-based PUSCH transmission to the terminal through higher layer signaling, such as RRC signaling.

[0280] For example, as illustrated in FIG. 6, time axis allocation information (601), frequency axis allocation information (602), period information (603), etc. for resources (600) can be set. In addition, the base station can set various parameters for PUSCH transmission to the terminal (e.g., frequency hopping, DMRS configuration, MCS table, MCS, RBG (Resource Block Group) size, number of repeated transmissions, RV (Redundancy Version), etc.) through upper layer signaling. More specifically, the configuration information of Table 19 below can be included.

[0281] [Table 19]

[0282]

[0283]

[0284] When the configuration information for non-grant-based PUSCH transmission type-1 is received from the base station, the terminal can transmit the PUSCH periodically with the configured resources (600) without the base station's approval. Various parameters required for transmitting the PUSCH (e.g., frequency hopping, DMRS configuration, MCS, RBG (Resource Block Group) size, number of repeated transmissions, RV (Redundancy Version), number of precoding and layers, antenna ports, frequency hopping offset, etc.) can all follow the configuration values ​​notified by the base station.

[0285] Non-acknowledgement-based PUSCH transmission type-2

[0286] In non-grant-based PUSCH transmission type 2, the base station can set some of the information (e.g., period information (603), etc.) regarding specific time / frequency resources (600) that allow non-grant-based PUSCH transmission to the terminal through higher layer signaling (e.g., RRC signaling). In addition, the base station can set various parameters for PUSCH transmission to the terminal through higher layer signaling (e.g., frequency hopping, DMRS configuration, MCS table, RBG (Resource Block Group) size, number of repetition transmissions, RV (Redundancy Version), etc.). More specifically, the base station can set the configuration information of Table 20 below to the terminal through higher layer signaling.

[0287] [Table 20]

[0288]

[0289] A base station may transmit a DCI composed of specific DCI field values ​​to a terminal for the purpose of scheduling activation or scheduling release for DL ​​SPS and UL grant Type 2.

[0290] To be more specific, it is as follows:

[0291] The base station can set a Configured Scheduling-RNTI (CS-RNTI) for the terminal, and the terminal can monitor the DCI format in which the CRC is scrambled with the CS-RNTI. If the CRC of the DCI format received by the terminal is scrambled with the CS-RNTI, the New Data Indicator (NDI) is set to '0', and the DCI field satisfies Table 21 below, the terminal can regard the DCI as a command to activate transmission and reception for DL ​​SPS or UL grant Type 2.

[0292] [Table 21]

[0293]

[0294] The base station can set a Configured Scheduling-RNTI (CS-RNTI) for the terminal, and the terminal can monitor the DCI format in which the CRC is scrambled with the CS-RNTI. If the CRC of the DCI format received by the terminal is scrambled with the CS-RNTI, the New Data Indicator (NDI) is set to '0', and the DCI field satisfies Table 22 below, the terminal can regard the DCI as a command to release transmission and reception for DL ​​SPS or UL grant Type 2.

[0295] [Table 22]

[0296]

[0297] The DCI indicating a release for the above DL SPS or UL grant Type 2 follows a DCI format corresponding to DCI format 0_0 or DCI format 1_0, and since DCI format 0_0 or 1_0 does not include a Carrier Indicator Field (CIF), the UE must always monitor the PDCCH in a cell in which the DL SPS or UL grant Type 2 is configured in order to receive a release command for the DL SPS or UL grant Type 2 for a specific cell. Even if a specific cell is configured for cross-carrier scheduling, the UE must always monitor the DCI format 1_0 or DCI format 0_0 in the cell in order to receive a release command for the DL SPS or UL grant Type 2 configured for the cell.

[0298] Below, carrier aggregation and scheduling methods in 5G communication systems are described in detail.

[0299] A terminal can be configured with multiple cells (Cells or CCs (Component Carriers)) from a base station, and can be configured with whether to perform cross-carrier scheduling for the cells configured in the terminal. If cross-carrier scheduling is configured for a specific cell (Cell A, Scheduled Cell), PDCCH monitoring for Cell A may not be performed in Cell A, but may be performed in another cell indicated by cross-carrier scheduling (Cell B, Scheduling Cell). In this case, the scheduled cell (Cell A) and the scheduling cell (Cell B) may be configured with different numerologies. Here, the numerologies may include subcarrier spacing, cyclic prefix, etc. When the numerologies of Cell A and Cell B are different, when the PDCCH of Cell B schedules the PDSCH of Cell A, the following minimum scheduling offset may be additionally considered between the PDCCH and the PDSCH.

[0300] Cross-carrier scheduling method

[0301] ◆ Subcarrier spacing of cell B ( ) is the subcarrier spacing of cell A ( ) is less than, the PDSCH can be scheduled from the next PDSCH slot corresponding to X symbols after the last symbol of the PDCCH received from cell B. Here, X is It may vary depending on When =15kHz, X=4 symbols, When =30kHz, X=4 symbols, When =60kHz, it can be defined as X=8 symbols.

[0302] ◆ Subcarrier spacing of cell B ( ) is the subcarrier spacing of cell A ( ) is greater than, the PDSCH can be scheduled from the point in time corresponding to X symbols after the last symbol of the PDCCH received from cell B. Here, X is It may vary depending on When =30kHz, X=4 symbols, When =60kHz, X=8 symbols, When =120kHz, it can be defined as X=12 symbols.

[0303] Below, the rate matching operation and puncturing operation are described in detail.

[0304] When a time and frequency resource A, through which an arbitrary symbol sequence A is to be transmitted, overlaps with an arbitrary time and frequency resource B, a rate matching or puncturing operation may be considered for transmission and reception operations of channel A considering resource C, an area in which resources A and B overlap. The specific operations may follow the contents below.

[0305] Rate Matching Operation

[0306] - The base station can map and transmit channel A only for the remaining resource areas excluding resource C corresponding to the overlapping area with resource B among the entire resources A that want to transmit symbol sequence A to the terminal. For example, if symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol #4}, resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the base station can sequentially map and transmit symbol sequence A to {resource #1, resource #2, resource #4}, which are the remaining resources among resource A excluding {resource #3} corresponding to resource C. As a result, the base station can map and transmit symbol sequences {symbol #1, symbol #2, symbol #3} to {resource #1, resource #2, resource #4}, respectively.

[0307] The terminal can determine resources A and B from scheduling information for symbol sequence A from the base station, and can thereby determine resource C, which is an area where resources A and B overlap. The terminal can receive symbol sequence A, assuming that symbol sequence A was mapped and transmitted in the remaining area of ​​the entire resource A except for resource C. For example, if symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol #4}, and resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the terminal can receive symbol sequence A, assuming that it was sequentially mapped to {resource #1, resource #2, resource #4}, which are the remaining resources among resource A except for {resource #3}, which corresponds to resource C. As a result, the terminal can perform a series of subsequent reception operations, assuming that symbol sequences {symbol #1, symbol #2, symbol #3} were mapped and transmitted to {resource #1, resource #2, resource #4}, respectively.

[0308] Puncture action

[0309] If a base station wants to transmit symbol sequence A to a terminal, and there is a resource C corresponding to an area overlapping with resource B among all resources A, the base station maps symbol sequence A to the entire resource A, but does not perform transmission in the resource area corresponding to resource C, and can perform transmission only for the remaining resource areas of resource A excluding resource C. For example, if symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol #4}, resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the base station can map symbol sequence A {symbol #1, symbol #2, symbol #3, symbol #4} to resource A {resource #1, resource #2, resource #3, resource #4}, and transmit only the symbol sequence {symbol #1, symbol #2, symbol #4} corresponding to the remaining resources {resource #1, resource #2, resource #4} excluding {resource #3} corresponding to resource C among resources A, and may not transmit {symbol #3} mapped to {resource #3} corresponding to resource C. As a result, the base station can transmit symbol sequences {symbol #1, symbol #2, symbol #4} by mapping them to {resource #1, resource #2, resource #4}, respectively.

[0310] The terminal can determine resources A and B from scheduling information for symbol sequence A from the base station, and can thereby determine resource C, which is an area where resources A and B overlap. The terminal can receive symbol sequence A assuming that symbol sequence A is mapped to the entire resource A, but is transmitted only in the remaining area of ​​resource area A excluding resource C. For example, if symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol #4}, resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the terminal can assume that symbol sequence A {symbol #1, symbol #2, symbol #3, symbol #4} is mapped to resource A {resource #1, resource #2, resource #3, resource #4} respectively, but {symbol #3} mapped to {resource #3} corresponding to resource C is not transmitted, and can receive it assuming that symbol sequence {symbol #1, symbol #2, symbol #4} corresponding to {resource #1, resource #2, resource #4}, which are the remaining resources among resource A except {resource #3} corresponding to resource C, are mapped and transmitted. As a result, the terminal can assume that the symbol sequence {symbol #1, symbol #2, symbol #4} is transmitted by being mapped to {resource #1, resource #2, resource #4}, respectively, and perform a series of subsequent receiving operations.

[0311] FIG. 10 is a diagram for explaining a method for a base station and a terminal to transmit and receive data by taking into account downlink data channels and rate matching resources according to one embodiment of the present disclosure.

[0312] Referring to FIG. 10, a downlink data channel (PDSCH, 1001) and a rate matching resource (1002) are illustrated. A base station can configure one or more rate matching resources (1002) to a terminal through upper layer signaling (e.g., RRC signaling). The rate matching resource (1002) configuration information may include time-domain resource allocation information (1003), frequency-domain resource allocation information (1004), and period information (1005). In the following, the bitmap corresponding to the frequency-domain resource allocation information (1004) is named "the first bitmap", the bitmap corresponding to the time-domain resource allocation information (1003) is named "the second bitmap", and the bitmap corresponding to the period information (1005) is named "the third bitmap". When all or part of the time and frequency resources of a scheduled data channel (1001) overlap with the set rate matching resources (1002), the base station can rate-match and transmit the data channel (1001) in the rate matching resource (1002) portion, and the terminal can perform reception and decoding after assuming that the data channel (1001) is rate-matched in the rate matching resource (1002) portion.

[0313] The base station can dynamically notify the terminal via DCI whether to rate-match the data channel in the set rate-matching resource portion through additional configuration (corresponding to the "rate-matching indicator" in the aforementioned DCI format). Specifically, the base station can select some of the set rate-matching resources and group them into rate-matching resource groups, and can use a bitmap to indicate to the terminal via DCI whether the data channel for each rate-matching resource group is rate-matched. For example, if four rate-matching resources, RMR#1, RMR#2, RMR#3, and RMR#4, are set, the base station can set RMG#1={RMR#1, RMR#2}, RMG#2={RMR#3, RMR#4} as the rate-matching groups, and can use two bits in the DCI field to indicate to the terminal whether to rate-match in RMG#1 and RMG#2, respectively, using a bitmap. For example, the base station can instruct the terminal to perform rate matching by indicating "1" when rate matching is required, and to not perform rate matching by indicating "0" when rate matching is not required.

[0314] 5G supports granularity at the "RB symbol level" and "RE level" by setting the aforementioned rate matching resources on the terminal. More specifically, the following setting method can be followed.

[0315] RB symbol level

[0316] A terminal can receive up to four RateMatchPatterns per bandwidth part through upper layer signaling, and one RateMatchPattern can include the following contents.

[0317] - As a reserved resource within the bandwidth part, a resource in which the time and frequency resource domains of the reserved resource are set by combining a bitmap at the RB level and a bitmap at the symbol level along the frequency axis may be included. The reserved resource may span one or two slots. A time domain pattern (periodicityAndPattern) in which the time and frequency domains composed of each RB level and symbol level bitmap pair are repeated may additionally be set.

[0318] - The bandwidth part may include a time and frequency domain resource area set as a control resource set and a resource area corresponding to a time domain pattern set as a search space setting in which the resource area is repeated.

[0319] RE level

[0320] The terminal can be configured with the following contents through upper layer signaling.

[0321] - The configuration information (lte-CRS-ToMatchAround) for RE corresponding to the LTE CRS (Cell-specific Reference Signal or Common Reference Signal) pattern may include the number of LTE CRS ports (nrofCRS-Ports) and the LTE-CRS-vshift(s) value (v-shift), the location information (carrierFreqDL) of the center subcarrier of the LTE carrier from the reference frequency point (e.g., reference point A), the bandwidth size (carrierBandwidthDL) information of the LTE carrier, and the subframe configuration information (mbsfn-SubframConfigList) corresponding to the MBSFN (Multicast-broadcast single-frequency network). Based on the above-described information, the terminal can determine the location of the CRS within the NR slot corresponding to the LTE subframe.

[0322] - It may contain configuration information for a set of resources corresponding to one or more ZP (Zero Power) CSI-RSs within the bandwidth part.

[0323] Below, we will specifically describe a method for measuring and reporting channel status in a 5G communication system.

[0324] Channel state information (CSI) may include a channel quality indicator (CQI), a precoding matrix indicator (PMI), a CSI-RS resource indicator (CRI), an SS / PBCH block resource indicator (SSBRI), a layer indicator (LI), a rank indicator (RI), and / or L1-RSRP (Reference Signal Received Power). The base station may control time and frequency resources for the aforementioned CSI measurement and reporting of the terminal.

[0325] For the aforementioned CSI measurement and reporting, the terminal may receive setting information (CSI-ReportConfig) for N (≥1) CSI reports, setting information (CSI-ResourceConfig) for M (≥1) RS transmission resources, and one or two trigger state lists (CSI-AperiodicTriggerStateList, CSI-SemiPersistentOnPUSCH-TriggerStateList) through upper layer signaling.

[0326] The setup information for the aforementioned CSI measurement and reporting may be as described more specifically in Tables 23 to 29 below.

[0327] [Table 23]

[0328]

[0329]

[0330]

[0331]

[0332]

[0333]

[0334] [Table 24]

[0335]

[0336] [Table 25]

[0337]

[0338] [Table 26]

[0339]

[0340] [Table 27]

[0341]

[0342] [Table 28]

[0343]

[0344]

[0345] [Table 29]

[0346]

[0347] For the aforementioned CSI report setting (CSI-ReportConfig), each report setting CSI-ReportConfig can be associated with one downlink (DL) bandwidth part identified by the upper layer parameter bandwidth part identifier (bwp-id) given by the CSI resource setting, CSI-ResourceConfig, associated with the corresponding report setting. For the time domain reporting operation for each report setting CSI-ReportConfig, 'Aperiodic', 'Semi-Persistent', and 'Periodic' methods are supported, which can be configured from the base station to the terminal by the reportConfigType parameter configured from the upper layer. The semi-persistent CSI reporting method supports 'PUCCH-based semi-persistent (semi-PersistentOnPUCCH)' and 'PUSCH-based semi-persistent (semi-PersistentOnPUSCH)'. For periodic or semi-permanent CSI reporting methods, the UE can receive PUCCH or PUSCH resources for transmitting CSI from the base station through higher-layer signaling. The period and slot offset of the PUCCH or PUSCH resources for transmitting CSI can be given as numerology of the uplink (UL) bandwidth portion configured for CSI report transmission. For aperiodic CSI reporting methods, the UE can receive scheduling of PUSCH resources for transmitting CSI from the base station through L1 signaling (the aforementioned DCI format 0_1).

[0348] For the aforementioned CSI resource setting (CSI-ResourceConfig), each CSI resource setting CSI-ReportConfig can include S (≥1) CSI resource sets (given by the upper layer parameter csi-RS-ResourceSetList). The CSI resource set list can be composed of a non-zero power (NZP) CSI-RS resource set and a SS / PBCH block set, or a CSI-interference measurement (CSI-IM) resource set. Each CSI resource setting can be located in a downlink (DL) bandwidth segment identified by the upper layer parameter bwp-id, and the CSI resource setting can be linked to a CSI reporting setting in the same downlink bandwidth segment. The time domain operation of the CSI-RS resources within the CSI resource setting can be set to one of 'aperiodic', 'periodic', or 'semi-persistent' from the upper layer parameter resourceType. For periodic or semi-permanent CSI resource settings, the number of CSI-RS resource sets can be limited to S=1, and the configured period and slot offset can be given as a numerology of a downlink bandwidth portion identified by bwp-id. A terminal can receive one or more CSI resource settings for channel or interference measurement from a base station through higher layer signaling, and may include, for example, the following CSI resources.

[0349] - CSI-IM resources for interference measurements

[0350] - NZP CSI-RS resources for interference measurements

[0351] - NZP CSI-RS resources for channel measurements

[0352] For CSI-RS resource sets associated with resource settings where the upper layer parameter resourceType is set to 'aperiodic', 'periodic', or 'semi-persistent', the trigger state for the CSI report setting where reportType is set to 'aperiodic' and the resource settings for channel or interference measurements for one or more component cells (CC) can be set with the upper layer parameter CSI-AperiodicTriggerStateList.

[0353] Aperiodic CSI reporting of a terminal can utilize PUSCH, periodic CSI reporting can utilize PUCCH, and semi-persistent CSI reporting can be performed using PUSCH when triggered or activated by DCI, or PUCCH after activation by MAC control element (MAC CE). As mentioned above, CSI resource settings can also be configured as aperiodic, periodic, or semi-persistent. Combinations between CSI reporting settings and CSI resource settings can be supported based on Table 30 below.

[0354] [Table 30]

[0355]

[0356] Aperiodic CSI reporting can be triggered by the "CSI request" field of the aforementioned DCI format 0_1 ​​corresponding to the scheduling DCI for the PUSCH. The UE can monitor the PDCCH, acquire the DCI format 0_1, and acquire scheduling information and a CSI request indicator for the PUSCH. The CSI request indicator is N TS(=0, 1, 2, 3, 4, 5, or 6) bits and can be determined by higher layer signaling (reportTriggerSize). One or more aperiodic CSI reporting trigger states that can be set by higher layer signaling (CSI-AperiodicTriggerStateList) can be triggered by the CSI request indicator.

[0357] - If all bits in the CSI request field are 0, this may mean that no CSI report is requested.

[0358] - If the number of CSI trigger states (M) in the configured CSI-AperiodicTriggerStateLite is greater than 2NTs-1, M CSI trigger states can be mapped to 2NTs-1 according to the mapping relationship defined, and one of the trigger states of 2NTs-1 can be indicated by the CSI request field.

[0359] - If the number of CSI trigger states (M) in the configured CSI-AperiodicTriggerStateLite is less than or equal to 2NTs-1, one of the M CSI trigger states can be indicated by the CSI request field.

[0360] Table 31 below shows an example of the relationship between a CSI request indicator and the CSI trigger state that can be indicated by the indicator.

[0361] [Table 31]

[0362]

[0363] A terminal may perform measurement on a CSI resource within a CSI trigger state triggered by a CSI request field, and may generate CSI (including at least one of the aforementioned CQI, PMI, CRI, SSBRI, LI, RI, or L1-RSRP) therefrom. The terminal may transmit the acquired CSI using a PUSCH scheduled by the corresponding DCI format 0_1. When 1 bit corresponding to the uplink data indicator (UL-SCH indicator) in the DCI format 0_1 ​​indicates "1", the terminal may multiplex and transmit the acquired CSI with uplink data (UL-SCH) on the PUSCH resource scheduled by the DCI format 0_1. When 1 bit corresponding to the uplink data indicator (UL-SCH indicator) in DCI format 0_1 ​​indicates "0", the terminal can transmit only CSI without uplink data (UL-SCH) by mapping it to the PUSCH resource scheduled by DCI format 0_1.

[0364] FIG. 11 is a diagram for explaining a method for a terminal to report aperiodic CSI when the CSI-RS offset is 0 according to one embodiment of the present disclosure.

[0365] Referring to FIG. 11, the terminal can monitor PDCCH (1101) to obtain DCI format 0_1, and from this, can obtain scheduling information and CSI request information for PUSCH (1105).

[0366] The terminal can obtain resource information about the CSI-RS (1102) to be measured from the received CSI request indicator.

[0367] The terminal can determine at what point in time to perform measurements on the transmitted CSI-RS (1102) resource based on the time of receiving the DCI format 0_1 ​​and the parameter for the offset (aperiodicTriggeringOffset described above) within the CSI resource set configuration (e.g., NZP CSI-RS resource set configuration (NZP-CSI-RS-ResourceSet)).

[0368] The terminal may receive an offset value X of the parameter aperiodicTriggeringOffset in the NZP-CSI-RS resource set configuration from the base station through upper layer signaling, and the configured offset value X may mean an offset between a slot in which a DCI triggering aperiodic CSI reporting is received and a slot in which a CSI-RS resource is transmitted. For example, the aperiodicTriggeringOffset parameter value and the offset value X may have a mapping relationship as described in Table 32 below.

[0369] [Table 32]

[0370]

[0371] Referring to FIG. 11, the aforementioned offset value may be set to X=0. In this case, the terminal may receive a CSI-RS (1102) in a slot (corresponding to slot 0 in FIG. 11) in which DCI format 0_1 ​​that triggers aperiodic CSI reporting is received, and may report CSI information measured with the received CSI-RS to the base station via PUSCH (1105). The terminal may obtain scheduling information (information corresponding to each field of the aforementioned DCI format 0_1) for the PUSCH (1105) for CSI reporting from the DCI format 0_1. For example, the terminal may obtain information on a slot in which the PUSCH (1105) is to be transmitted from the aforementioned time domain resource allocation information for the PUSCH (1105) in the DCI format 0_1. In an example of FIG. 11, the terminal acquires a K2 value corresponding to a slot offset value for PDCCH-to-PUSCH as 3, and accordingly, the PUSCH (1105) can be transmitted in slot 3 (1109), which is 3 slots away from slot 0 (1106), at the time when the PDCCH (1101) is received.

[0372] FIG. 12 is a diagram for explaining a method for a terminal to report aperiodic CSI when the CSI-RS offset is 1 according to one embodiment of the present disclosure.

[0373] In an example of FIG. 12, the terminal can monitor PDCCH (1201) to obtain DCI format 0_1, and from this, can obtain scheduling information and CSI request information for PUSCH (1205).

[0374] The terminal can obtain resource information about the CSI-RS (1202) to be measured from the received CSI request indicator.

[0375] An example of FIG. 12 shows an example in which the offset value for the aforementioned CSI-RS is set to X=1. In this case, the terminal can receive the CSI-RS (1202) in a slot (corresponding to slot 0 (1206) in FIG. 13) in which the DCI format 0_1 ​​that triggers aperiodic CSI reporting is received, and can report the CSI information measured with the received CSI-RS to the base station via the PUSCH (1205).

[0376] Next, we will specifically explain the bandwidth part (BWP) settings in the 5G communication system.

[0377] FIG. 13 is a diagram for explaining settings for a bandwidth part in a 5G communication system according to one embodiment of the present disclosure.

[0378] Referring to FIG. 13, the UE bandwidth (1400) can be set to two bandwidth parts, namely, bandwidth part #1 (BWP#1) (1301) and bandwidth part #2 (BWP#2) (1302). The base station can set one or more bandwidth parts to the UE, and can set the following information for each bandwidth part, as shown in Table 33.

[0379] [Table 33]

[0380]

[0381] The above information can be transmitted from the base station to the terminal via higher-layer signaling, such as RRC (Radio Resource Control) signaling. At least one bandwidth part among one or more configured bandwidth parts can be activated. Whether or not the configured bandwidth part is activated can be semi-statically transmitted from the base station to the terminal via RRC signaling or dynamically transmitted via DCI (Downlink Control Information).

[0382] Before RRC (Radio Resource Control) connection, a terminal can receive the initial bandwidth part (Initial BWP) for initial connection from the base station through MIB (Master Information Block). More specifically, during the initial connection phase, the terminal can receive configuration information about a control region (Control Resource Set, CORESET) and a search space where a PDCCH (Physical Downlink Control Channel) for receiving system information (Remaining System Information; which may correspond to RMSI or System Information Block 1; SIB1) required for initial connection can be transmitted through MIB. The control region and search space configured by MIB can each be regarded as identifier (Identity, ID) 0. The base station can notify the terminal of configuration information such as frequency allocation information, time allocation information, and numerology for control region #0 through MIB. Additionally, the base station can notify the terminal of the monitoring cycle and occasion settings for control area #0, i.e., search space #0, via the MIB. The terminal can consider the frequency range designated as control area #0, obtained from the MIB, as the initial bandwidth part for initial access. At this time, the identifier (ID) of the initial bandwidth part can be considered as 0.

[0383] The settings for the bandwidth part supported by the above 5G can be used for various purposes.

[0384] In one embodiment, when the bandwidth supported by a terminal is smaller than the system bandwidth, this can be supported through bandwidth part settings. For example, by setting the frequency location (setting information 2) of the bandwidth part to the terminal, the base station can enable the terminal to transmit and receive data at a specific frequency location within the system bandwidth.

[0385] To support different numerologies, a base station can configure multiple bandwidth parts for a terminal. For example, to support data transmission and reception using both 15 kHz and 30 kHz subcarrier spacing for a given terminal, two bandwidth parts can be configured with subcarrier spacings of 15 kHz and 30 kHz, respectively. These different bandwidth parts can be frequency-division multiplexed, and when data is to be transmitted or received using a specific subcarrier spacing, the bandwidth part configured for that subcarrier spacing can be activated.

[0386] Additionally, for the purpose of reducing power consumption of the terminal, the base station can configure bandwidth parts with different bandwidth sizes for the terminal. For example, if the terminal supports a very large bandwidth, such as 100 MHz, and constantly transmits and receives data using that bandwidth, it can result in very high power consumption. In particular, monitoring unnecessary downlink control channels using a large bandwidth of 100 MHz in a traffic-free environment can be very inefficient in terms of power consumption. To reduce power consumption of the terminal, the base station can configure a bandwidth part with a relatively small bandwidth, such as 20 MHz, for the terminal. In a traffic-free environment, the terminal can perform monitoring operations using the 20 MHz bandwidth part, and when data is generated, it can transmit and receive data using the 100 MHz bandwidth part according to the instructions of the base station.

[0387] In the method for setting the bandwidth part, terminals prior to RRC connection can receive configuration information for the initial bandwidth part through the MIB (Master Information Block) during the initial access stage. More specifically, the terminal can receive a control region (Control Resource Set, CORESET) for a downlink control channel on which DCI (Downlink Control Information) for scheduling a SIB (System Information Block) can be transmitted from the MIB of the PBCH (Physical Broadcast Channel). The bandwidth of the control region set by the MIB can be regarded as the initial bandwidth part, and the terminal can receive the PDSCH (Physical Downlink Shared Channel) on which the SIB is transmitted through the set initial bandwidth part. In addition to receiving the SIB, the initial bandwidth part can also be utilized for other system information (Other System Information, OSI), paging, and random access.

[0388] When one or more bandwidth parts are set for a terminal, the base station can instruct the terminal to change the bandwidth part using the bandwidth part indicator field in the DCI. For example, referring to FIG. 3, when the currently activated bandwidth part of the terminal is bandwidth part #1 (1301), the base station can instruct the terminal to bandwidth part #2 (1302) using the bandwidth part indicator in the DCI, and the terminal can perform a bandwidth part change to bandwidth part #2 (1302) indicated by the bandwidth part indicator in the received DCI.

[0389] As described above, since DCI-based bandwidth part changes can be indicated by DCI scheduling PDSCH or PUSCH (Physical Uplink Shared Channel), when a UE receives a bandwidth part change request, it must be able to seamlessly receive or transmit the PDSCH or PUSCH scheduled by the corresponding DCI in the changed bandwidth part. To this end, the standard specifies requirements for the delay time (TBWP) required when changing the bandwidth part, which can be defined, for example, as shown in Table 34 below.

[0390] [Table 34]

[0391]

[0392] The bandwidth part change delay time requirement supports Type 1 or Type 2 depending on the terminal's capability. The terminal can report the supported bandwidth part delay time type to the base station.

[0393] According to the requirement on the bandwidth part change delay time described above, when a terminal receives a DCI including a bandwidth part change indicator in slot n, the terminal can complete the change to the new bandwidth part indicated by the bandwidth part change indicator no later than slot n + TBWP, and can perform transmission and reception for the data channel scheduled by the corresponding DCI in the changed new bandwidth part. When the base station wants to schedule a data channel with the new bandwidth part, the base station can determine the time domain resource allocation for the data channel by considering the bandwidth part change delay time (TBWP) of the terminal. That is, when the base station schedules a data channel with the new bandwidth part, the data channel can be scheduled after the bandwidth part change delay time in the method of determining the time domain resource allocation for the data channel. Accordingly, the terminal may not expect that the DCI indicating the bandwidth part change indicates a slot offset (K0 or K2) value smaller than the bandwidth part change delay time (TBWP).

[0394] If the terminal receives DCI (e.g., DCI format 1_1 or 0_1) indicating a bandwidth part change, the terminal may not perform any transmission or reception during the time period corresponding to the third symbol of the slot in which the PDCCH including the DCI is received, to the start point of the slot indicated by the slot offset (K0 or K2) value indicated by the time domain resource allocation indicator field in the DCI. For example, if the terminal receives DCI indicating a bandwidth part change in slot n and the slot offset value indicated by the DCI is K, the terminal may not perform any transmission or reception from the third symbol of slot n to the symbol before slot n+K (i.e., the last symbol of slot n+K-1).

[0395] Next, we will explain how to set transmission and reception related parameters for each bandwidth part in 5G.

[0396] The terminal can be configured with one or more bandwidth parts from the base station, and can additionally be configured with parameters to be used for transmission and reception for each configured bandwidth part (e.g., configuration information related to uplink / downlink data channels and control channels, etc.). For example, referring to FIG. 13, if the terminal is configured with bandwidth part #1 (1301) and bandwidth part #2 (1302), the terminal can be configured with transmission / reception parameter #1 for bandwidth part #1 (1301), and can be configured with transmission / reception parameter #2 for bandwidth part #2 (1302). When bandwidth part #1 (1301) is activated, the terminal can perform transmission and reception with the base station based on transmission / reception parameter #1, and when bandwidth part #2 (1302) is activated, the terminal can perform transmission and reception with the base station based on transmission / reception parameter #2.

[0397] More specifically, the following parameters can be set from the base station to the terminal.

[0398] First, for the uplink bandwidth part, the information in Table 35 can be set.

[0399] [Table 35]

[0400]

[0401] According to [Table 35], the terminal can be configured with cell-specific (or cell common or common) transmission-related parameters (e.g., parameters related to a Random Access Channel (RACH), a Physical Uplink Control Channel (PUCCH), and a Physical Uplink Shared Channel)) from the base station (corresponding to BWP-UplinkCommon). In addition, the terminal can be configured with terminal-specific (or dedicated) transmission-related parameters (e.g., parameters related to a PUCCH, a PUSCH, a Configured Grant PUSCH, and a Sounding Reference Signal (SRS)) from the base station (corresponding to BWP-UplinkDedicated).

[0402] Next, for the downlink bandwidth part, the following information can be set as in Table 36.

[0403] [Table 36]

[0404]

[0405] According to [Table 36], the terminal can be configured with cell-specific (or cell common or common) reception-related parameters (e.g., parameters related to a downlink control channel (PDCCH) and a downlink data channel (Physical Downlink Shared Channel)) from the base station (corresponding to BWP-DownlinkCommon). In addition, the terminal can be configured with terminal-specific (or dedicated) reception-related parameters (e.g., parameters related to a PDCCH, a PDSCH, a semi-persistent scheduled PDSCH, and radio link monitoring (RLM)) from the base station (corresponding to BWP-UplinkDedicated).

[0406] Below, we will specifically explain the DRX (Discontinuous Reception) settings in a 5G communication system.

[0407] FIG. 14 is a diagram for explaining DRX (Discontinuous Reception) in a 5G communication system according to one embodiment of the present disclosure.

[0408] DRX is an operation in which a terminal using a service discontinuously receives data while in an RRC Connected state, where a wireless link is established between the base station and the terminal. When DRX is applied, the terminal turns on the receiver at a specific time to monitor the control channel, and if no data is received for a certain period of time, the receiver is turned off, reducing the terminal's power consumption. DRX operation can be controlled by the MAC layer device based on various parameters and timers.

[0409] Referring to Figure 14, Active time (1405) is the time when the terminal wakes up every DRX cycle and monitors the PDCCH. Active time (1405) can be defined as follows.

[0410] - drx-onDurationTimer or drx-InactivityTimer or drx-RetransmissionTimerDL or drx-RetransmissionTimerUL or ra-ContentionResolutionTimer is running; or

[0411] - a Scheduling Request is sent on PUCCH and is pending; or

[0412] - a PDCCH indicating a new transmission addressed to the C-RNTI of the MAC entity has not been received after successful reception of a Random Access Response for the Random Access Preamble not selected by the MAC entity among the contention-based Random Access Preamble

[0413] drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, ra-ContentionResolutionTimer, etc. are timers whose values ​​are set by the base station, and have the function of setting the terminal to monitor the PDCCH when a certain condition is met.

[0414] drx-onDurationTimer(1415) is a parameter for setting the minimum time for which the terminal stays awake in the DRX cycle. drx-InactivityTimer(1420) is a parameter for setting the additional time for which the terminal stays awake when receiving (1430) a PDCCH indicating a new uplink transmission or downlink transmission. drx-RetransmissionTimerDL is a parameter for setting the maximum time for which the terminal stays awake to receive a downlink retransmission in a downlink HARQ procedure. drx-RetransmissionTimerUL is a parameter for setting the maximum time for which the terminal stays awake to receive an uplink retransmission grant in an uplink HARQ procedure. drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, and drx-RetransmissionTimerUL can be set as, for example, time, the number of subframes, the number of slots, etc. ra-ContentionResolutionTimer is a parameter for monitoring PDCCH in random access procedure.

[0415] The inActive time (1410) is a time set not to monitor PDCCH during DRX operation and / or a time set not to receive PDCCH. The remaining time excluding the Active time (1405) from the entire time of performing the DRX operation can be the inActive time (1410). If the terminal does not monitor the PDCCH during the Active time (1405), it can enter a sleep or inActive state to reduce power consumption.

[0416] DRX cycle refers to the period during which the terminal wakes up and monitors the PDCCH. In other words, it refers to the time interval or on duration that occurs after the terminal monitors the PDCCH until it monitors the next PDCCH. There are two types of DRX cycles: short DRX cycle and long DRX cycle. Short DRX cycle can be applied optionally.

[0417] Long DRX cycle (1425) is the longer cycle among the two DRX cycles set in the terminal. While operating in Long DRX, the terminal starts drx-onDurationTimer (1415) again at a point in time when Long DRX cycle (1425) has elapsed from the starting point (e.g., start symbol) of drx-onDurationTimer (1415). When operating in Long DRX cycle (1425), the terminal can start drx-onDurationTimer (1415) in a slot after drx-SlotOffset in a subframe satisfying [Mathematical Formula 2] below. Here, drx-SlotOffset means a delay before starting drx-onDurationTimer (1415). drx-SlotOffset can be set to, for example, time, the number of slots, etc.

[0418] [Equation 2]

[0419]

[0420] At this time, drx-LongCycleStartOffset can include Long DRX cycle (1525) and drx-StartOffset, and can be used to define a subframe to start Long DRX cycle (1425). For example, drx-LongCycleStartOffset can be set to time, number of subframes, number of slots, etc.

[0421] A Short DRX cycle is the shorter cycle of the two DRX cycles defined in the terminal. The terminal operates in a Long DRX cycle (1425), and when a certain event occurs during the Active time (1405), for example, when a PDCCH indicating a new uplink transmission or downlink transmission is received (1430), the terminal starts or restarts the drx-InactivityTimer (1420), and if the drx-InactivityTimer (1420) expires or a DRX command MAC CE is received, the terminal can operate in a short DRX cycle.

[0422] For example, in FIG. 14, the terminal may start drx-ShortCycleTimer at the time when the previous drx-onDurationTimer (1415) or drx-InactivityTimer (1420) expires, and operate in a short DRX cycle until the drx-ShortCycleTimer expires. When the terminal receives (1430) a PDCCH indicating a new uplink transmission or downlink transmission, the terminal may extend the Active Time (1405) or delay the arrival of the InActive Time (1410) in anticipation of additional uplink transmission or downlink transmission in the future.

[0423] While the terminal operates in short DRX, drx-onDurationTimer (1415) starts again when the number of short DRX cycles has elapsed from the start of the previous on duration. After that, when drx-ShortCycleTimer expires, the terminal operates in long DRX cycle (1425) again.

[0424] When operating in a short DRX cycle, the terminal can start drx-onDurationTimer (1415) after drx-SlotOffset in a subframe satisfying [Mathematical Formula 3] below. Here, drx-SlotOffset refers to a delay before starting drx-onDurationTimer (1415). For example, drx-SlotOffset can be set to time, number of slots, etc.

[0425] [Equation 3]

[0426]

[0427] Here, drx-ShortCycle and drx-StartOffset can be used to define the subframe at which the Short DRX cycle will start. drx-ShortCycle and drx-StartOffset can be set to, for example, time, number of subframes, number of slots, etc.

[0428] According to one embodiment, a terminal can reduce its power consumption by performing a DRX operation. However, even if the terminal performs a DRX operation, the terminal does not always receive a PDCCH related to the terminal during the Active Time (1405). Therefore, in one embodiment of the present disclosure, a signal for controlling the operation of the terminal can be provided to more efficiently save power of the terminal.

[0429] In 5G systems, a new terminal state called RRC_INACTIVE has been defined to reduce the energy and time consumed during initial access. In addition to the actions performed by RRC_IDLE terminals, RRC_INACTIVE terminals can perform the following processes:

[0430] - Storage of AS (Access stratum) information required for cell connection

[0431] - Terminal-specific DRX cycle operation set by the RRC layer

[0432] - Setting up and periodically updating RNA (RAN (radio access network)-based notification area) that can be utilized during handover by the RRC layer

[0433] - Monitoring of RAN-based paging messages transmitted via I-RNTI (inactive-radio network temporary identifier)

[0434] A terminal in RRC_CONNECTED state can change from RRC_CONNECTED to RRC_INACTIVE or RRC_IDLE state by receiving an RRC Release instruction from the base station.

[0435] A terminal in RRC_INACITVE or RRC_IDLE state can change from RRC_INACTIVE or RRC_IDLE to RRC_CONNECTED state by performing random access and completing all random access procedures.

[0436] Below, a scheduling method for a base station to transmit downlink data to a terminal or instruct the terminal to transmit uplink data is described.

[0437] Downlink Control Information (DCI) may be control information transmitted from a base station to a terminal via the downlink. Downlink control information may include downlink data scheduling information or uplink data scheduling information for a given terminal. Typically, the base station independently performs channel coding on DCI for each terminal and then transmits it to each terminal via the Physical Downlink Control Channel (PDCCH).

[0438] The base station can operate by applying a DCI format determined for the purpose of scheduling, such as whether it is scheduling information for downlink data (downlink assignment), scheduling information for uplink data (uplink grant), or DCI for power control.

[0439] The base station can transmit downlink data to the terminal via the Physical Downlink Shared Channel (PDSCH), a physical channel for downlink data transmission. The base station can inform the terminal of scheduling information such as the specific mapping location in the time and frequency domain of the PDSCH, modulation method, HARQ-related control information, and power control information through DCI related to downlink data scheduling information among the DCI transmitted via the PDCCH.

[0440] A terminal can transmit uplink data to a base station via the Physical Uplink Shared Channel (PUSCH), a physical channel for uplink data transmission. The base station can inform the terminal of scheduling information such as specific mapping locations in the time and frequency domains of the PUSCH, modulation schemes, HARQ-related control information, and power control information through DCI related to uplink data scheduling information among the DCI transmitted via the PDCCH.

[0441] For RRC_IDLE / RRC_INACTIVE terminals, the above-mentioned DRX operation is performed and a paging message is received. The terminal can monitor one paging occasion (PO) during a DRX cycle. A PO may be a set of PDCCH monitoring occasions and may include multiple time slots (or subframes, or OFDM symbols) in which paging control information may be transmitted and received. A paging frame (PF) may be one radio frame (10 ms) and may include one or multiple POs or starting points (e.g., offsets) of POs.

[0442] PF and PO can be determined by the following formulas:

[0443] The SFN (System Frame Number) for PF can be determined by (SFN + PF_offset) mod T = (T div N)*(UE_ID mod N), where PF_offset is an offset for PF determination, T is a DRX cycle, N is the number of PFs per DRX cycle (e.g., cell common, cell specific), which can be determined by higher-level signals such as system information, and UE_ID is a terminal ID (e.g., 5G-S-TMSI), which can be determined by the core network.

[0444] The PFs determined by N may refer to paging frames commonly applied to terminals within a cell, and may be referred to as cell common PFs for convenience hereinafter.

[0445] i_s, which indicates the PO index, can be determined by i_s = floor (UE_ID / N) mod Ns, where Ns can mean the number of POs in one PF and can be determined by a higher-order signal such as system information.

[0446] For example, if PF_offset=3, T=128, N=T / 4=32, Ns=4, and UE_ID mod 32 is 1, and floor (UE_ID / 32) mod 4 is 1, then the values ​​of the parameters can be determined by the following formula.

[0447] (SFN + 3) mod 128 = (128 div 32)*(UE_ID mod 32) = 4*1 = 4,

[0448] i_s = floor (UE_ID / 32) mod 4 = 1

[0449] Accordingly, the PF, which is a paging frame that a terminal with the above UE_ID must receive, can be determined as a radio frame with SFN of 1, 129, 257, ... among the common PFs of the cell, and the PO can be determined as the (i_s + 1)th PO among the four POs in the PF.

[0450] Hereinafter, the reception of PEI (Paging Early Indication) is described in more detail. In order to reduce terminal power consumption while monitoring and receiving the paging control channel and paging data channel in each DRX cycle, the terminal can receive PEI.

[0451] According to various embodiments of the present disclosure, a terminal may monitor or receive one PEI Occasion (PEI-O) before receiving paging during a DRX cycle. When the terminal receives a PEI and the PEI indicates a subgroup to which the terminal belongs and a paging okay, the terminal belonging to the subgroup may monitor the associated paging okay (PO). If the terminal does not detect the PEI in the PEI okay or the PEI does not indicate a subgroup to which the terminal belongs and a paging okay, the terminal does not need to monitor the associated paging okay (PO), thereby reducing terminal power consumption.

[0452] The terminal can determine PEI occupancy as follows. The PEI occupancy can be set to a subframe offset behind the radio frame of the reference point that is located ahead of the PF containing the associated PO by pei-FrameOffset. The terminal can monitor PEI in the PEI occupancy determined by the above method. Here, pei-FrameOffset, subframe offset, etc. can be determined by higher-level signals such as system information.

[0453] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. The contents of the present disclosure can be applied to FDD, TDD and / or XDD (and / or SBFD, full duplex) systems. In the present disclosure below, upper signaling (or upper layer signaling) refers to a signal transmission method in which a base station transmits a signal to a terminal using a downlink data channel of a physical layer, or a terminal transmits a signal to a base station using an uplink data channel of a physical layer, and may also be referred to as RRC signaling, PDCP signaling, or MAC (medium access control) control element (MAC control element; MAC CE).

[0454] For convenience in the following description of the present disclosure, cells, transmission points, panels, beams, and / or transmission directions, which can be distinguished through upper layer / L1 parameters such as TCI state or spatial relation information, or indicators such as cell ID, TRP ID, and panel ID, may be uniformly described as TRP (transmission reception point), beam, or TCI state. Therefore, when actually applying the present disclosure, TRP, beam, or TCI state may be appropriately replaced with one of the above terms.

[0455] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. Hereinafter, a base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, a gNB, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. Although embodiments of the present disclosure are described below using a 5G system as an example, embodiments of the present disclosure may be applied to other communication systems having similar technical backgrounds or channel types. For example, LTE or LTE-A mobile communication and mobile communication technologies developed after 5G may be included here. Therefore, embodiments of the present disclosure may be applied to other communication systems with some modifications without significantly departing from the scope of the present disclosure as determined by a person skilled in the art. The contents of the present disclosure can be applied to FDD, TDD, XDD (or SBFD, full duplex) systems.

[0456] Additionally, when describing the present disclosure, detailed descriptions of related 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 the functions of 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 contents of this specification.

[0457] In the following description of the present disclosure, upper layer signaling may be signaling corresponding to at least one or a combination of one or more of the following signaling.

[0458] - MIB (Master Information Block)

[0459] - SIB (System Information Block) or SIB

[0460] - RRC (Radio Resource Control)

[0461] - MAC (Medium Access Control) CE (Control Element)

[0462] In addition, L1 signaling may be signaling corresponding to at least one or a combination of one or more signaling methods using the physical layer channel or signaling below.

[0463] - PDCCH (Physical Downlink Control Channel)

[0464] - DCI (Downlink Control Information)

[0465] - UE-specific DCI

[0466] - Group common DCI

[0467] - Common DCI

[0468] - Scheduling DCI (e.g. DCI used for scheduling downlink or uplink data)

[0469] - Non-scheduled DCI (e.g. DCI not intended for scheduling downlink or uplink data)

[0470] - PUCCH (Physical Uplink Control Channel)

[0471] - UCI (Uplink Control Information)

[0472] The term slot used in the present disclosure below is a general term that may refer to a specific time unit corresponding to a TTI (Transmit Time Interval), and may specifically mean a slot used in a 5G NR system, or a slot or subframe used in a 4G LTE system.

[0473] In the present disclosure, deep sleep and ultra deep sleep can be distinguished based on which components within a cell / base station can be turned off. For example, if the main radio (MR) is completely OFF, all components within the main radio can be OFF. When the main radio is in deep sleep, the oscillator, radio frequency-front end (RF-FE), and baseband modem can be OFF, while the control processor and double data rate (DDR) memory can still be ON. When the main radio is in ultra deep sleep, the oscillator, radio frequency-front end (RF-FE), and baseband modem can be OFF, and the control processor and DDR memory can also operate at very low power or be completely OFF.

[0474] The present disclosure can be applied to RRC idle, RRC inactive, and RRC connected terminals.

[0475] In the present disclosure, the statement that a particular cell is for data communication and / or only for data communication may include that the particular cell performs not only data communication but also other signal transmission and reception. For example, signal transmission and reception other than sync and / or connection may be included in data communication.

[0476] In the present disclosure, transitioning a cell to a specific state may include maintaining the specific state without changing the state. For example, transitioning a cell to a deep sleep state or an ultra deep sleep state may include maintaining the cell in a deep sleep state or an ultra deep sleep state.

[0477] In the present disclosure below, the above examples are described through a number of embodiments, but they are not independent and one or more embodiments may be applied simultaneously or in combination.

[0478] As mentioned above, 5G systems support ultra-wide bandwidth signal transmission and reception or utilize spatial multiplexing using multiple transmit / receive antennas to achieve ultra-high-speed data services reaching several Gbps. Furthermore, they support various power-saving modes to reduce terminal power consumption. However, excessive power consumption can also occur at base stations.

[0479] For example, the number of power amplifiers (PAs) required increases proportionally to the number of transmitting antennas installed at a base station or terminal. The maximum output of the base station and terminal depends on the characteristics of the PA, and the maximum output of the base station generally varies depending on the size of the cell covered by the base station. The maximum output is usually expressed in dBm. The maximum output of the terminal is usually 23 dBm or 26 dBm.

[0480] An example of a commercial 5G base station might feature 64 transmit antennas and corresponding 64 power amplifiers operating in the 3.5 GHz frequency band, operating at a bandwidth of 100 MHz. Ultimately, the base station's energy consumption increases in proportion to the power amplifier output and operating time.

[0481] Compared to LTE base stations, 5G base stations feature relatively high operating frequency bands, resulting in wider bandwidth and numerous transmitting antennas. While these features have the effect of increasing data rates, they also 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.

[0482] As mentioned above, the energy consumption of a base station is largely dependent on 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 the base station's energy consumption. The uplink (UL) reception operation of the base station accounts for a relatively small portion of the base station's energy consumption. The physical channels and physical signals transmitted by the base station in the downlink are as follows.

[0483] - PDSCH (Physical Downlink Shared Channel): A downlink data channel containing data to be transmitted to one or more terminals.

[0484] - PDCCH (Physical Downlink Control Channel): A downlink control channel that includes scheduling information for PDSCH and PUSCH (Physical Uplink Control Channel). Alternatively, the PDCCH may be transmitted alone without the PDSCH or PUSCH to be scheduled, and control information such as slot format and power control commands may be transmitted on the PDCCH. The scheduling information includes resource information to which the PDSCH or PUSCH is mapped, information related to HARQ (hybrid automatic repeat request), power control information, etc.

[0485] - 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.

[0486] - PSS (Primary Synchronization Signal): A signal that serves as the basis for DL ​​time and / or frequency (hereinafter time / frequency) synchronization and provides some cell ID information.

[0487] - SSS (Secondary Synchronization Signal): A signal that serves as the basis for DL ​​time / frequency synchronization and provides some of the remaining information including the cell ID.

[0488] - DM-RS (Demodulation Reference Signal): Reference signal for channel estimation of terminals for each of PDSCH, PDCCH, and PBCH.

[0489] - CSI-RS (Channel-state Information Reference Signal): A downlink signal that serves as a basis for measuring the terminal's downlink channel status.

[0490] - PT-RS (Phase-tracking Reference Signal): Downlink signal for phase tracking

[0491] From the perspective of base station energy saving, when the base station stops downlink transmission operation, the power amplifier operation is stopped accordingly, which increases the base station energy saving effect, and the operation of the remaining base station devices, such as the baseband device as well as the power amplifier, is also reduced, enabling additional energy saving.

[0492] Similarly, even if uplink reception operations account for a relatively small portion of the base station's total energy consumption, additional energy savings can be achieved if uplink reception operations can be stopped.

[0493] The downlink transmission behavior of a base station fundamentally depends on the amount of downlink traffic. For example, if there is no data to transmit to the terminal via the downlink, the base station does not need to transmit the PDSCH or the PDCCH to schedule the PDSCH. Alternatively, if the data can be temporarily delayed for reasons such as insensitivity to transmission delay, the base station may refrain from transmitting the PDSCH and / or PDCCH.

[0494] 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, the PSS, SSS, PBCH, and CSI-RS must be transmitted on the downlink regardless of downlink data traffic, and this causes base station energy consumption. Therefore, base station energy savings can be achieved by controlling the transmission of the signals unrelated to (or with low relevance to) data traffic to occur less frequently.

[0495] Through the above two base station energy saving methods, 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.

[0496] Alternatively, energy consumption at a base station can be reduced by switching off some of its antennas or power amplifiers. However, this energy-saving effect may be counterproductive, such as reduced cell coverage or throughput.

[0497] For example, if a base station equipped with 64 transmit antennas and corresponding 64 power amplifiers in the 3.5 GHz frequency band as described above and operating with a bandwidth of 100 MHz activates only 4 transmit antennas and 4 power amplifiers for a certain period of time and switches off the rest in order to save base station energy, the base station energy consumption during that period will be reduced to approximately 1 / 16 (=4 / 64), but it will be difficult to achieve cell coverage and throughput assuming the existing 64 antennas and power amplifiers due to the decrease in maximum transmission power and decrease in beamforming gain.

[0498] The above base station energy saving methods can be further categorized into three types. There is a base station energy saving method in the frequency domain that adjusts the size of the BWP according to the base station traffic, a base station energy saving method in the space domain that adaptively reduces the number of antenna ports, and a base station energy saving method in the time domain that adjusts the cycles of CSI-RS, SSB, and DRX. These three base station energy saving methods are used alone or in combination according to the characteristics of the base station, such as base station traffic or coverage, and the corresponding change information must be shared / transmitted to the terminal.

[0499] The above energy-saving method can be implemented within a single base station or across multiple base stations. When implemented within a single base station, the presence of idle UEs can result in only very limited energy savings. Therefore, cooperating with multiple base stations to implement base station energy savings can yield greater energy-saving benefits.

[0500] The following describes the base station energy-saving method proposed in this disclosure through specific examples. The first through third embodiments described below may be implemented separately and / or at least partially combined.

[0501] <Example 1>

[0502] The first embodiment is a method for realizing energy saving through cooperation between a base station and a terminal.

[0503] FIG. 15 is a drawing for explaining an energy saving method according to one embodiment of the present disclosure.

[0504] Referring to Fig. 15, a base station can have two configurations for energy saving of the base station. Configuration 2 (1502) is when the base station operates in normal mode (e.g., all antennas of the base station can be used for data transmission). The time resource scheduled for data (1522) indicated through a control channel (e.g., PDCCH (1521)) is the same as time resource 2.

[0505] However, assuming that the channel status of the base station and the terminal are the same and the same data is transmitted, if Configuration 1 (1501) operates in the energy saving mode of the base station (for example, data transmission can be performed by reducing the number of antennas of the base station), the signal-to-noise ratio becomes lower than that of Configuration 2, so the time resource scheduled for data (1512) indicated through the control channel (for example, PDCCH (1511)) becomes much longer than that of time resource 2 for time resource 1.

[0506] Therefore, when operating in configuration 2, the terminal experiences high energy efficiency, and when operating in configuration 1, the terminal experiences low energy efficiency.

[0507] In other words, if only the energy saving of the base station is considered, the energy saving of the terminal will be detrimental. Therefore, in order for both the base station and the terminal to achieve energy saving, an appropriate configuration must be selected by considering the trade-off in energy consumption between the two through close cooperation between the base station and the terminal.

[0508] For example, since the base station does not know the power consumption of these terminals without any feedback, it determines the configuration for data transmission without considering the terminals. Therefore, when the terminal transmits information (1540) related to the energy consumption of the terminal to the base station, the base station knows both the energy information consumed by the base station and the energy information consumed by the terminal, and can therefore determine the appropriate configuration 3 (1503) required for transmitting data (1532).

[0509] Assuming that the channel status of the base station and the terminal are the same and the same data is being sent, the base station transmits data (1532) for a time called time resource 3 through configuration 3, and time resource 3 can have a value between time resource 1 and time resource 2.

[0510] FIG. 16 is a diagram for explaining a method for a terminal to perform handover to another base station based on link quality and energy consumption.

[0511] Referring to FIG. 16, Cell 1 (1601) is a serving cell of the terminal (1600) and performs data transmission and reception for the terminal.

[0512] If the terminal is deemed to be consuming excessive power, it can revert to its energy-saving mode. At this time, if the terminal is performing energy-saving, the base station may reject the terminal's operation in energy-saving mode, believing the link quality to be below a threshold. In this case, the terminal can perform a handover to another cell that allows operation in energy-saving mode. Therefore, the terminal searches for other nearby cells. For example, the terminal can detect the presence of cell 2 through the RS (1603) transmitted from cell 2 (1602) and measure RSRP through the RS.

[0513] The terminal can calculate the energy consumption until receiving the RS. Therefore, the terminal can send RSRP and energy consumption-related information (1604) as feedback to cell 1 (1601). At this time, the terminal can send RSRSP and energy consumption-related information to cell 1 based on the RS transmitted from the serving cell, cell 1. Since cell 1 has all RSRP and energy consumption information for cell 1 and cell 2, it can determine whether cell 2 is more energy efficient and instruct to perform a handover.

[0514] <Example 2>

[0515] The second embodiment relates to energy-related information of the terminal, and this information can be transmitted to the base station as is or in a processed form.

[0516] In cellular communications, terminals communicate with base stations by measuring specific values. Terminal measurements can be categorized into explicit and implicit measurements. Explicit measurements, such as RSSI and RSRP, are absolute values ​​based on radio signals. These values ​​can be used by terminals for serving cell selection or reported to the base station for use in handovers. For example, from the base station's perspective, RSRP is a measured power value that can be used for mobility purposes, indicating the wireless distance from the BS to the UE. Implicit measurements, on the other hand, are formalized indices representing explicit measurements that have no clear meaning to the receiver, such as PMI / RI as a channel matrix, CQI as capacity, and SINR as an interference hypothesis.

[0517] For example, from the base station's perspective, CQI is an index of the available link capacity that a user can achieve under certain conditions and assumptions, which means the wireless link capacity from the BS to the UE. In reality, the terminal determines the CQI based on the SINR calculated through measurement, but this process varies depending on the terminal's implementation, so the determination method may vary by manufacturer. Therefore, the energy-related information described in the first embodiment can be accurately measured by the terminal through explicit measurement, and can be fed back to the base station through processing by the terminal through implicit measurement.

[0518] The energy consumption of these terminals is determined by a combination of CQI index, active BWP size (or CSI-RS BW), number of carrier components, number of receiving antennas, center frequency, base station antenna configuration, number of MIMO layers, manufacturer-specific parameters, CPU usage, etc. Accordingly, the terminal transmits an explicit or implicit measurement value to the base station based on the measured energy, and the base station can determine a configuration or scheduling parameter suitable for the terminal based on this. The following three factors can be considered regarding the energy-related information reported by the terminal to the base station, but are not limited thereto.

[0519] Regarding what a terminal should report, the simplest and most reliable approach, considering energy-related measurement information, is for the terminal to explicitly transmit its energy consumption. This consumption can be transmitted periodically or aperiodically. However, because energy consumption varies by terminal manufacturer, it can be difficult for terminal manufacturers to directly report this value to the base station.

[0520] Alternatively, implicit information can be reported to the base station as a function of the terminal's energy consumption. This information is referred to as EQI (energy quality information) hereinafter.

[0521] Regarding how the UE reports the EQI, the UE can report the EQI as explicit or implicit information. If the EQI is transmitted for operations related to data transmission and reception, the UE can transmit the EQI similarly to the CQI. If the EQI is used for mobility purposes (e.g., handover to an energy-efficient cell as shown in FIG. 16), the UE can transmit the EQI together with the RSRP. In this case, the EQI can be measured per RS ​​(e.g., SSB) and reported to the base station at a rapid interval (i.e., L1 EQI), or it can be measured for multiple RSs and the average value reported to the base station (i.e., L3 EQI).

[0522] Regarding how the UE measures energy consumption, like the existing RS, the UE can measure energy consumption based on the RS. However, this can only obtain information related to the number of antennas, which accounts for the majority of energy consumption, and does not reflect the energy consumed by the CPU for the UE to receive and decode data. Therefore, it may be necessary to measure it based on a specific data resource (e.g., PDSCH). If the EQI, which is a function of the UE's energy consumption, is not a value related to the actual measured energy consumption, but a function of the resources consumed to transmit the reference bit (resource elements, number of transmit / receive antennas, etc.). In this case, as with the CQI, calculation using virtual data resources instead of physical data resources may be sufficient. Based on the three considerations above, the UE can transmit information related to energy consumption to the base station for the EQI.

[0523] The above example illustrates a configuration for downlink energy savings, where the base station receives EQI from the terminal and jointly manages energy between the terminal and the base station. Similarly, for uplink, the terminal can determine uplink transmission power by calculating energy information while receiving RS (e.g., SRS) transmitted by the terminal from the base station. This energy-related information from the base station can be transmitted to the terminal as measured energy values ​​or in a processed form.

[0524] <Example 3>

[0525] The third embodiment relates to an example in which a terminal transmits EQI.

[0526] FIG. 17 is a diagram for explaining a method for a terminal to report an EQI that measures energy consumption based on physical resources according to one embodiment of the present disclosure.

[0527] According to Fig. 17, the terminal measures RS through RS (1701, e.g., CSI-RS) and calculates the energy E required to calculate PMI / RI. RS can be measured. A reference resource (1702) can be set at the closest location based on the RS. This reference resource can be composed of X slots and Y PRBs. For example, the reference resource can be set to 1 slot as in (1704) and can have the same bandwidth as RS (1701). The reference resource (1702) can include a control channel (e.g., PDCCH), a data channel (PDSCH), and DMRS for channel estimation for decoding. That is, through this reference resource, the terminal performs channel estimation, PDCCH decoding, and PDSCH decoding with DMRS. In this process, the terminal consumes energy E for the reference resource. RR As mentioned in the second embodiment, the terminal E RR The terminal can report EQI directly to the base station (1703), but to prevent direct energy consumption from being transmitted to the base station, the terminal must report EQI to the base station. RR / E RS can be reported as EQI. If E RS Assuming that E is the standard energy consumption, RR can indicate how much energy was consumed compared to the reference energy. Also, the terminal can calculate the calculated E RR / E RS Based on this, the quantized bits can be transmitted as EQI as follows.

[0528] [Table 37]

[0529]

[0530] Table 37 shows the quantization of EQI into two bits, E RR / E RS Here is an example where values ​​are quantized according to specific intervals.

[0531] In addition, CQI can be transmitted along with EQI. That is, since the base station has information on both EQI and CQI, it can calculate the energy efficiency of the next transmitted data as follows.

[0532] [Equation 4]

[0533]

[0534] Here is the number of PDSCH symbols within the reference resource. That is, the terminal can calculate the energy efficiency for the next data transmission and reception, which is equal to the maximum number of bits that can be transmitted in the current channel state per reference energy. In addition, the terminal can directly report the energy efficiency value to the base station. Therefore, the linear value or dB scale value for the value of mathematical expression 4 can be quantized and transmitted as shown in Table 37.

[0535] If the reference resource (1702) is a virtual resource, the maximum number of bits that can be transmitted can be expressed as an energy-related element set in the reference resource. For example, it can be set as in Equation 5.

[0536] [Equation 5]

[0537]

[0538] Here, RI is the rank indicator predicted by the terminal through CSI-RS. is the number of CSI-RS ports, is the size of the activated BWP, When considering CA, the number of component carriers, is the number of receiving antennas, CPU usage and / or manufacturer-specific parameters, is a value according to carrier frequency. At least for each terminal Since the values ​​may vary, the calculated energy efficiency value in Equation 5 varies for each terminal. Considering overhead, the terminal can transmit the calculated energy efficiency value as a linear value or quantized in dB scale, as shown in Table 37.

[0539] Figure 18 is a diagram for explaining a downlink L3-based handover operation based on EQI.

[0540] According to FIG. 18, the terminal (1801) detects high energy consumption from the serving cell (1802) and requests power saving mode from the serving cell.

[0541] When a terminal executes power saving mode, the link quality between the base station and the terminal may not be measured correctly, so the serving cell may not indicate power saving mode to the terminal.

[0542] The UE (1801) can initiate a handover to another cell that will activate power saving mode. To do this, the base station must search for possible candidate cells, so it sends a measurement request to the UE. The neighboring cell (1803), which has received the trigger from the serving cell, transmits an RS (e.g., SSB). During the configured measurement gap, the UE (1801) measures RSRP and energy consumption via the RS, and reports this to the serving cell (1802).

[0543] Based on this, the serving cell (1802) can decide whether to perform a handover to the target neighboring cell (1803).

[0544] The serving cell (1802) sends a handover request to the neighboring cell (1803). When the neighboring cell (1803) sends an ACK to the serving cell (1802), the serving cell (1802) performs RRC reconfiguration on the terminal (1801) so that the terminal can perform the remaining handover procedures.

[0545] At this time, the EQI transmitted by the terminal (1801) to the serving cell (1802) may be a direct energy consumption value or a processed value.

[0546] FIG. 19 is a diagram for explaining energy-related measurements measured and reported by a terminal according to one embodiment of the present disclosure for searching for surrounding base stations.

[0547] The terminal can measure the RS of the serving cell (cell 1, 1901) and neighboring cells (cell 2, 1902) within the measurement gap (1903) set by the base station. The terminal can average the RSRP values ​​and energy consumption values ​​measured through the RSs during the measurement gap.

[0548] That is, for energy consumption, the average energy consumption measured for base station i is E RS,i If so, the terminal is EQI (1904) RS,2 / E RS,1 can be reported. As in Fig. 17, E RS,1 By setting the reference energy as the energy, we can check how much energy is consumed in the neighboring cell compared to the serving cell. This value takes into account the overhead, and the terminal calculates the E RS,2 / E RS,1The values ​​can be transmitted by quantizing them into linear values ​​or dB scale values ​​as shown in Table 37.

[0549] <Example 4>

[0550] The fourth embodiment relates to the operations of a base station and a terminal related to EQI transmission.

[0551] EQI can work with RRC configuration from the base station for multiple energy configurations.

[0552] For example, a terminal can receive multiple antenna configurations via RRC and calculate EQI through energy measurement for each configuration.

[0553] The terminal may send EQI for all configurations, or only for the configuration with the smallest EQI value.

[0554] If the terminal sends EQI for all configurations, the terminal can additionally provide the base station with the terminal's preferred configuration as UE assistance information (UAI) for the configuration with the smallest EQI value.

[0555] FIG. 20 is a diagram for explaining the transmission timing and configuration update when a terminal transmits EQI for CSI purposes according to one embodiment of the present disclosure.

[0556] According to FIG. 20, the terminal can receive the CSI-RS (2001) set to Configuration 1 for CSI purposes and calculate the PMI / RI. Based on the calculated PMI / RI, the CQI is calculated in the RR (2002), and at the same time, the energy consumption can be measured to calculate the EQI.

[0557] The terminal transmits CSI information for CQI / PMI / RI through PUCCH (2003), and can simultaneously send the calculated EQI.

[0558] The base station can update the configuration required for the next data transmission from configuration 1 to configuration 2 based on the received EQI and CSI information.

[0559] The terminal can receive PDCCH (2004) and data (2005) for scheduling purposes based on the updated configuration. That is, for this purpose, the content for UCI must be updated to include EQI in addition to CSI information.

[0560] Additionally, terminals transmit EQIs to the base station for energy conservation purposes. However, transmitting EQIs at every CSI transmission cycle can actually increase energy consumption or increase RR overhead. To address this, terminals can transmit EQIs in an event-triggered manner.

[0561] For example, when a terminal wants to change its configuration, or when a physical RR is set and the terminal successfully decodes the RR, the terminal can transmit an EQI to the base station.

[0562] When a physical RR is configured and the terminal successfully decodes the RR, the terminal can replace this by transmitting an EQI instead of sending a separate ACK for the RR to the base station. That is, if the terminal does not separately send an EQI for the RR, the base station can consider it a NACK and send the RR more robustly.

[0563] FIG. 21 is a diagram illustrating the operation of a terminal according to one embodiment of the present disclosure for maintaining an energy efficiency level when EQI operates for CSI purposes.

[0564] According to Fig. 21, a reference energy efficiency level Y may exist for each base station, each terminal group, or each terminal. Configuration adaptation may be performed so that the energy efficiency of the terminal can be maintained at Y.

[0565] That is, if the energy efficiency calculated based on the EQI of the terminal is greater than Y, the base station increases the energy configuration (2101) to bring the energy efficiency of the terminal closer to Y.

[0566] If the energy efficiency of the terminal is less than Y, the energy configuration is reduced (2102) to bring the energy efficiency of the terminal closer to Y. In addition, this configuration can be changed more slowly than the MCS configuration to reduce the overhead of RR compared to CSI-RS.

[0567] That is, the terminal can adjust the energy efficiency as close to Y as possible with small scale variation based on AMC (2103) by performing CSI feedback for a given configuration (or set).

[0568] FIG. 22 is a block diagram illustrating a terminal transmitting and receiving device according to one embodiment of the present disclosure.

[0569] Referring to FIG. 22, the terminal may include a transmitter (2204) including an uplink transmission processing block (2201), a multiplexer (2202), and a transmission RF block (2203), a receiver (2208) including a downlink reception processing block (2205), a demultiplexer (2206), and a reception RF block (2207), and a control unit (2209). The control unit (2209) may control each of the configuration blocks of the receiver (2208) for receiving a data channel or control channel transmitted by the base station as described above, and each of the configuration blocks of the transmitter (2204) for transmitting an uplink signal.

[0570] In the transmitter (2204) of the terminal, the uplink transmission processing block (2201) 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 (2201) can be multiplexed with another uplink signal by a multiplexer (2202), and then transmitted to the base station after signal processing in the transmission RF block (2203).

[0571] The terminal's receiving unit (2208) demultiplexes the signal received from the base station and distributes it to each downlink receiving processing block. The downlink receiving processing block (2205) 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 terminal receiving unit (2208) can support the operation of the control unit (2209) by applying the output result of the downlink receiving processing block to the control unit (2209).

[0572] FIG. 23 is a block diagram illustrating components of a terminal according to one embodiment of the present disclosure.

[0573] A terminal according to an embodiment of the present disclosure may include a processor (2330), a transceiver (2310), and a memory (2320). 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 (2330), the transceiver (2310), and the memory (2320) may be implemented in the form of a single chip. According to one embodiment, the transceiver (2310) of FIG. 23 may include the transmitter (2204) and receiver (2208) of FIG. 22. In addition, the processor (2330) of FIG. 23 may include the control unit (2209) of FIG. 22.

[0574] According to one embodiment, the processor (2330) 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 depending on whether the base station mode is the base station energy saving mode or the base station normal mode. There may be one or more processors (2330), and the processors (2330) may execute a program stored in the memory (2320) to perform transmission and reception operations of the terminal in a wireless communication system that applies the carrier bundle of the present disclosure described above.

[0575] The processor (2330) can control the overall operation of the terminal according to the embodiments proposed in the present disclosure by executing one or more commands stored in the memory (2320).

[0576] The processor (2330) may include various processing circuits and / or multiple processors. For example, the term “processor” as used herein, including in the claims, may include various processing circuits, including at least one processor. One or more processors in at least one processor may be configured to perform various functions described herein, individually and / or collectively, in a distributed fashion. As used herein, “processor,” “at least one processor,” and “one or more processors” may be configured to perform various functions. However, these terms encompass, without limitation, situations where one processor performs some of the functions and other processor(s) perform other parts of the functions, and situations where a single processor may perform all of the functions. Furthermore, the at least one processor may include a combination of processors that perform various functions of the disclosed functions in a distributed manner. The at least one processor may execute program instructions to achieve or perform various functions.

[0577] In one embodiment, at least one processor (2330) may be a general-purpose processor, such as a CPU, AP, or DSP (Digital Signal Processor), a graphics-only processor, such as a GPU or VPU (Vision Processing Unit), or an AI-only processor, such as an NPU. For example, if one or more processors are AI-only processors, the AI-only processors may be designed with a hardware structure specialized for processing a specific AI model.

[0578] The transceiver (2310) 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 (2310) 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 a received signal and down-converts the frequency, etc. However, the transceiver (2310) is only one embodiment, and the components of the transceiver (2310) are not limited to the RF transmitter and RF receiver. In addition, the transceiver (2310) can receive a signal through a wireless channel and output it to the processor (2330), and transmit a signal output from the processor (2330) through the wireless channel.

[0579] According to one embodiment, the memory (2320) can store programs and data necessary for the operation of the terminal. In addition, the memory (2320) can store control information or data included in signals transmitted and received by the terminal. The memory (2320) 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 (2320) can be plural. According to one embodiment, the memory (2320) can store a program for performing transmission and reception operations of the terminal depending on whether the base station mode of the embodiments of the present disclosure described above is a base station energy saving mode or a base station normal mode.

[0580] FIG. 24 is a block diagram illustrating components of a base station according to one embodiment of the present disclosure.

[0581] As illustrated in FIG. 24, the base station of the present disclosure may include a processor (2430), a transceiver (2410), and a memory (2420). 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. Furthermore, the processor (2430), the transceiver (2410), and the memory (2420) may be implemented in the form of a single chip.

[0582] The processor (2430) may control a series of processes so that the base station can operate according to the embodiments of the present disclosure described above. For example, the processor may control components of the base station to perform a method of scheduling a terminal according to whether the base station mode is a base station energy saving mode or a base station normal mode according to the embodiments of the present disclosure. There may be one or more processors (2430), and the processors (2430) may perform the methods of the present disclosure described above by executing a program stored in the memory (2420).

[0583] The processor (2430) can control the overall operation of the base station according to the embodiments proposed in the present disclosure by executing one or more commands stored in the memory (2420).

[0584] Processor (2430) may include various processing circuits and / or multiple processors. For example, the term “processor” as used herein, including in the claims, may include various processing circuits, including at least one processor. One or more processors in at least one processor may be configured to perform various functions described herein, individually and / or collectively, in a distributed fashion. As used herein, “processor,” “at least one processor,” and “one or more processors” may be configured to perform multiple functions. However, these terms encompass, without limitation, situations where one processor performs some of the functions and other processor(s) perform other parts of the functions, and situations where a single processor may perform all of the functions. Furthermore, at least one processor may include a combination of processors that perform various functions of the disclosed functions in a distributed manner. At least one processor may execute program instructions to achieve or perform various functions.

[0585] In one embodiment, at least one processor (2430) may be a general-purpose processor, such as a CPU, AP, or DSP (Digital Signal Processor), a graphics-only processor, such as a GPU or VPU (Vision Processing Unit), or an AI-only processor, such as an NPU. For example, if one or more processors are AI-only processors, the AI-only processors may be designed with a hardware structure specialized for processing a specific AI model.

[0586] The transceiver (2410) can transmit and receive signals with the terminal. The signals transmitted and received with the terminal can include control information and data. The transceiver (2410) 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 (2410) is only one embodiment, and the components of the transceiver (2410) are not limited to the RF transmitter and RF receiver. In addition, the transceiver (2410) can receive a signal through a wireless channel and output it to the processor (2430), and transmit a signal output from the processor (2430) through the wireless channel.

[0587] According to one embodiment, the memory (2420) can store programs and data necessary for the operation of the base station. In addition, the memory (2420) can store control information or data included in signals transmitted and received by the base station. The memory (2420) 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, there can be a plurality of memories (2420). According to one embodiment, the memory (2420) can store a program for performing the methods of the embodiments of the present disclosure described above.

[0588] According to one embodiment of the present disclosure, by defining a signal transmission method of a base station in a wireless communication system, the problem of excessive energy consumption can be solved and high energy efficiency can be achieved.

[0589] The effects that can be obtained from various embodiments of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by a person having ordinary skill in the art based on the detailed description below.

[0590] 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.

[0591] A method of operating a terminal according to one embodiment may include a step of synchronizing with a first cell.

[0592] A method of operating a terminal according to one embodiment may include a step of receiving a first control signal including information about a controllable cell by a first cell.

[0593] A method of operating a terminal according to one embodiment may include a step of transmitting data to a second cell based on a first control signal.

[0594] A method of operating a base station according to one embodiment may include a step of receiving a first control signal from a terminal.

[0595] A method of operating a base station according to one embodiment may include generating a second control signal based on a first control signal.

[0596] A method of operating a base station according to one embodiment may include a step of transmitting a second control signal to a terminal. 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 disclosure, 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.

[0597] 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. For example, some or all of the embodiments may be combined with some or all of one or more other embodiments, and such combinations should naturally correspond to embodiments proposed in this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be determined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. In a method of UE (user equipment) in a wireless communication system, A step of receiving a signal from a base station through at least one reference resource; A step of measuring energy consumption based on at least one reference resource; A step of generating information related to energy consumption of the UE based on the measurement results; and A method comprising: a step of transmitting information related to energy consumption of the UE to the base station; 2. A method according to claim 1, wherein the information related to energy consumption of the UE includes information on the ratio of the amount of energy consumed when receiving the signal through the at least one reference resource to the amount of energy consumed when receiving the reference signal.

3. A method according to claim 1, wherein the information related to energy consumption of the UE includes one index value among a plurality of index values ​​defined to indicate the amount of energy consumption of the terminal.

4. A method according to claim 1, wherein the reference resource includes at least one of a channel state information-reference signal (CSI-RS), a synchronization signal block (SSB), a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), or a demodulation reference signal (DMRS).

5. A method according to claim 1, wherein information related to energy consumption of the UE is generated based on the amount of energy consumed upon reception of a signal through one reference resource in the physical layer.

6. In the first paragraph, the information related to the energy consumption of the UE is generated based on the average energy efficiency according to the reception of signals through multiple reference resources in the upper layer.

7. In paragraph 1, A method further comprising: receiving, from the base station, configuration information including transmission-related parameters determined based on information related to energy consumption of the UE or information regarding whether or not to perform a handover.

8. In paragraph 1, A step of receiving a plurality of transmission-related setting information from the base station through RRC (radio resource control) signaling; and A method further comprising the step of transmitting information related to energy consumption associated with at least one of the plurality of transmission-related setting information to the base station.

9. In paragraph 8, A method further comprising: a step of transmitting, to the base station, transmission-related configuration information preferred by the UE based on information related to energy consumption associated with at least one of the plurality of transmission-related configuration information.

10. In a method of a base station in a wireless communication system, A step of transmitting a signal to a UE (user equipment) through at least one reference resource; A step of receiving information related to energy consumption of the UE from the UE; the information related to energy consumption of the UE is associated with the energy consumption of the UE measured based on the at least one reference resource, A step of determining transmission-related parameters or whether to handover based on information related to energy consumption of the UE; and A method comprising: a step of transmitting, to the UE, configuration information including transmission-related parameters determined based on information related to energy consumption of the UE or information regarding whether or not to perform a handover.

11. In a wireless communication system, in UE (user equipment), A memory in which a program or at least one instruction is stored; and Contains at least one processor, By the at least one processor executing the program or the at least one instruction stored in the memory, either alone or in cooperation, the UE, Receive a signal from a base station through at least one reference resource; Measure energy consumption based on at least one reference resource; Based on the above measurement results, information related to energy consumption of the UE is generated; and A UE that transmits information related to energy consumption of the UE to the base station.

12. In the 11th paragraph, the information related to energy consumption of the UE includes information on the ratio of the amount of energy consumed when receiving the signal through the at least one reference resource to the amount of energy consumed when receiving the reference signal.

13. In the 11th paragraph, the information related to the energy consumption of the UE includes one index value among a plurality of index values ​​defined to indicate the energy consumption of the terminal.

14. In the 11th paragraph, the reference resource is a UE including at least one of a channel state information-reference signal (CSI-RS), a synchronization signal block (SSB), a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), or a demodulation reference signal (DMRS).

15. In a base station in a wireless communication system, A memory in which a program or at least one instruction is stored; and Contains at least one processor, By the at least one processor executing the program or the at least one instruction stored in the memory, either alone or in cooperation, the base station, Transmitting a signal to a UE (user equipment) through at least one reference resource; Receive information related to energy consumption of the UE from the UE; and the information related to energy consumption of the UE is associated with energy consumption of the UE measured based on the at least one reference resource. Based on information related to energy consumption of the UE, transmission-related parameters or whether to perform a handover are determined; and A base station that transmits, to the UE, configuration information including transmission-related parameters or information regarding whether or not to perform a handover, determined based on information related to energy consumption of the UE.

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