Method and device for energy saving in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. A method performed by a terminal of a communication system of the present disclosure comprises the steps of: receiving secondary cell (SCell) group configuration information from a base station, wherein the secondary cell group configuration information includes configuration information for a plurality of SCells; receiving signaling related to activation of an on-demand synchronization signal block (SSB) on a specific SCell from the base station; and receiving the on-demand SSB on the specific SCell.

Description

Method and device for energy saving in wireless communication systems

[0001] The present disclosure relates to the operation of a terminal and a base station in a wireless communication system. Specifically, the present disclosure relates to a method and device for energy saving 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] With the recent development of 5G / 6G communication systems that take the environment into consideration, the need for methods to reduce energy consumption of communication systems (e.g., terminals, base stations, networks, etc.) or methods for energy saving is emerging.

[0009] Various embodiments of the present disclosure provide that, in a wireless communication system, a base station can perform on-demand operations on a secondary cell (SCell) during carrier aggregation (CA) operations for a terminal to reduce energy consumption. At this time, the base station can configure a secondary cell group and activate / deactivate SCells and configure on-demand operations for the on-demand operations on the SCell through upper layer signaling and / or L1 signaling. At this time, an operation method of the terminal according to each setting can be provided.

[0010] Various embodiments of the present disclosure may provide a method for configuring on-demand operations via higher layer signaling (e.g., RRC signaling), and may provide methods for activating and deactivating SCells or activating and deactivating on-demand operations via higher layer signaling and / or L1 signaling. In addition, operations according to the above-described settings of the terminal may be defined.

[0011] The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present disclosure pertains from the description below.

[0012] A method according to one embodiment of the present disclosure is characterized in that it comprises a step of receiving secondary cell (SCell) group configuration information from a base station, wherein the secondary cell group configuration information includes configuration information for a plurality of SCells; a step of receiving signaling related to activation of an on-demand SSB (synchronization signal block) on a specific SCell from the base station; and a step of receiving the on-demand SSB on the specific SCell.

[0013] In addition, the signaling related to activation of on-demand SSB on the specific SCell corresponds to radio resource control (RRC) signaling, and activation of the specific SCell and activation of the on-demand SSB can be indicated by the RRC signaling. In addition, the signaling related to activation of on-demand SSB on the specific SCell corresponds to medium access control control element (MAC CE), and activation of the on-demand SSB can be indicated by the MAC CE. In addition, the method may further include a step of performing measurement based on the on-demand SSB; and a step of transmitting a CSI (channel state information) report or a measurement report to the base station.

[0014] In addition, a method performed by a base station of a communication system is characterized by including a step of transmitting secondary cell (SCell) group configuration information to a terminal, wherein the secondary cell group configuration information includes configuration information for a plurality of SCells; a step of transmitting signaling related to activation of an on-demand SSB (synchronization signal block) on a specific SCell to the terminal; and a step of transmitting the on-demand SSB on the specific SCell.

[0015] In addition, in a terminal of a communication system, the terminal is characterized by including a transceiver; and a control unit configured to receive secondary cell (SCell) group configuration information from a base station, wherein the secondary cell group configuration information includes configuration information for a plurality of SCells, receive signaling related to activation of an on-demand SSB (synchronization signal block) on a specific SCell from the base station, and receive the on-demand SSB on the specific SCell.

[0016] In addition, in a base station of a communication system, the system comprises a transceiver; and a control unit configured to transmit secondary cell (SCell) group configuration information to a terminal, wherein the secondary cell group configuration information includes configuration information for a plurality of SCells, transmit signaling related to activation of an on-demand SSB (synchronization signal block) on a specific SCell to the terminal, and transmit the on-demand SSB on the specific SCell.

[0017] According to one embodiment of the present disclosure, in a 5G mobile communication system, unnecessary energy consumption of a base station can be reduced by transmitting signals and channels (e.g., SSB or SIB1) that are always transmitted periodically only when necessary through on-demand operation of a base station.

[0018] Additionally, terminal operation can be provided during on-demand operation of the base station for energy saving of the base station.

[0019] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0020] FIG. 1 is a diagram illustrating a basic structure of a time-frequency domain, which is a wireless resource domain, in a wireless communication system according to one embodiment of the present disclosure.

[0021] FIG. 2 is a diagram illustrating a slot structure considered in a wireless communication system according to one embodiment of the present disclosure.

[0022] FIG. 3 is a diagram illustrating an example of a time domain mapping structure and beam sweeping operation of a synchronization signal according to one embodiment of the present disclosure.

[0023] FIG. 4 is a diagram illustrating a synchronization signal block considered in a wireless communication system according to one embodiment of the present disclosure.

[0024] FIG. 5 is a diagram illustrating an example of various transmissions of a synchronization signal block in a frequency band below 6 GHz considered in a wireless communication system according to one embodiment of the present disclosure.

[0025] FIG. 6 is a diagram illustrating an example of transmission of a synchronization signal block in a frequency band of 6 GHz or higher considered in a wireless communication system according to one embodiment of the present disclosure.

[0026] FIG. 7 is a diagram illustrating an example of transmission of a synchronization signal block according to a subcarrier interval within 5 ms in a wireless communication system according to an embodiment of the present disclosure.

[0027] FIG. 8 is a diagram illustrating an example of DMRS patterns (type 1 and type 2) used for communication between a base station and a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0028] FIG. 9 is a diagram illustrating an example of channel estimation using DMRS received in one PUSCH in a time band of a wireless communication system according to one embodiment of the present disclosure.

[0029] FIG. 10 is a diagram illustrating an example of a method for resetting SSB transmission through dynamic signaling in a wireless communication system according to one embodiment of the present disclosure.

[0030] FIG. 11 is a diagram illustrating an example of a method for resetting BWP and BW through dynamic signaling in a wireless communication system according to one embodiment of the present disclosure.

[0031] FIG. 12 is a diagram illustrating an example of a method for resetting DRX through dynamic signaling in a wireless communication system according to one embodiment of the present disclosure.

[0032] FIG. 13 is a diagram illustrating an example of a DTx method for base station energy saving according to one embodiment of the present disclosure.

[0033] FIG. 14 is a diagram illustrating an example of the operation of a base station according to gNB WUS according to one embodiment of the present disclosure.

[0034] FIG. 15 is a diagram illustrating an example of an antenna adaptation method of a base station for energy saving in a wireless communication system according to one embodiment of the present disclosure.

[0035] FIG. 16 is a diagram illustrating an example of On-demand SSB operation of a base station and a terminal according to one embodiment of the present disclosure.

[0036] FIG. 17 is a diagram illustrating an example of a method for activating / deactivating SCell and setting On-demand SSB of a base station according to one embodiment of the present disclosure.

[0037] FIG. 18 is a diagram illustrating an example of a method for activating / deactivating a MAC CE-based SCell and setting an On-demand SSB of a base station according to one embodiment of the present disclosure.

[0038] FIG. 19 is a diagram illustrating an example of operation of a terminal according to CA settings of a base station according to one embodiment of the present disclosure.

[0039] FIG. 20 is a diagram illustrating an example of operation of a terminal according to CA settings and on-demand settings of a base station according to one embodiment of the present disclosure.

[0040] FIG. 21 is a diagram illustrating an example of operation of a terminal according to CA settings and on-demand settings of a base station according to one embodiment of the present disclosure.

[0041] FIG. 22 is a flowchart illustrating an example of an operation of a terminal performing an energy saving method of a wireless communication system according to one embodiment of the present disclosure.

[0042] FIG. 23 is a flowchart illustrating an example of an operation of a base station performing an energy saving method of a wireless communication system according to one embodiment of the present disclosure.

[0043] FIG. 24 is a block diagram illustrating an example of the structure of a terminal according to one embodiment of the present disclosure.

[0044] FIG. 25 is a block diagram illustrating an example of the structure of a base station according to one embodiment.

[0045] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0046] In describing embodiments of the present disclosure below, descriptions of technical details that are well known in the technical field of the present disclosure and are not directly related to the present disclosure will be omitted. This is to avoid obscuring the gist of the present disclosure by omitting unnecessary explanations and to convey the gist more clearly.

[0047] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[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 together with the accompanying drawings. However, the present disclosure is not limited to the embodiments described below and may be implemented in various different forms. These embodiments are provided only to make the present disclosure complete and to fully inform those skilled in the art of the present disclosure of the scope of the technical idea, and the present disclosure is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification. In addition, the terms described below are terms defined in consideration of the functions in the present disclosure and may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout the specification.

[0049] Hereinafter, the base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, 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. In the present disclosure, the downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station to a terminal, and the uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station.

[0050] Furthermore, while the LTE or LTE-A system may be described below as an example, embodiments of the present disclosure may also be applied to other communication systems with similar technical backgrounds or channel types. For example, this may include the fifth-generation mobile communication technology (5G, new radio, NR) developed after LTE-A, and the term "5G" below may also encompass existing LTE, LTE-A, and other similar services. Furthermore, the present disclosure may be applied to other communication systems with some modifications within the scope of the present disclosure, as determined by a person with skilled technical knowledge.

[0051] 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).

[0052] 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.

[0053] The term '~ unit' used in this disclosure means a software or hardware component such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), and the '~ unit' performs certain roles. However, the '~ unit' is not limited to software or hardware. The '~ unit' may be configured to be on an addressable storage medium and may be configured to play one or more processors. Thus, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. 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.

[0054] The methods and devices proposed in the embodiments of the present disclosure are not limited to each embodiment, and may be utilized as a combination of one or more embodiments, all or part of the embodiments proposed in the disclosure. Accordingly, the embodiments of the present disclosure may be applied with some modifications within a scope that does not significantly deviate from the scope of the present disclosure, as determined by a person skilled in the art.

[0055] Wireless communication systems are evolving from providing voice-oriented services in the early days to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as 3GPP's HSPA (high speed packet access), LTE (long term evolution or E-UTRA (evolved universal terrestrial radio access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2's HRPD (high rate packet data), UMB (ultra mobile broadband), and IEEE's 802.17e communication standards.

[0056] The LTE system, a representative example of a broadband wireless communication system, employs the orthogonal frequency division multiplexing (OFDM) method in the downlink and the single carrier frequency division multiple access (SC-FDMA) method in the uplink. In addition, the aforementioned multiple access method typically allocates and operates the time-frequency resources for transmitting data or control information to each user so that they do not overlap, that is, so that orthogonality is achieved, thereby distinguishing the data or control information of each user.

[0057] 5G communication systems, the successor to LTE, must support services that simultaneously satisfy diverse requirements, allowing them to freely reflect the diverse needs of users and service providers. Services being considered for 5G communication systems include enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable low-latency communication (URLLC).

[0058] eMBB aims to provide data transmission rates that are significantly higher than those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must be able to provide a peak data rate of 20 Gbps in the downlink and a peak data rate of 10 Gbps in the uplink from the perspective of a single base station. Furthermore, 5G communication systems must provide not only the peak data rate but also the increased user-perceived data rate for terminals. To meet these requirements, improvements in various transmission and reception technologies, including improved multi-input, multi-output (MIMO) transmission technology, may be required. Furthermore, while LTE systems transmit signals using a maximum transmission bandwidth of 20 MHz in the 2 GHz band, 5G communication systems can meet the data transmission rates required by 5G communication systems by using a wider frequency bandwidth than 20 MHz in the 3 to 6 GHz or higher frequency bands.

[0059] At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide the Internet of Things, mMTC requires supporting a large number of terminals within a cell, improving terminal coverage, extending battery life, and reducing terminal costs. The Internet of Things provides communication functions by attaching various sensors and various devices, so a large number of terminals (e.g., 1,000,000 terminals / km) are required within a cell. 2 ) must be able to support. Furthermore, terminals supporting mMTC are likely to be located in shadow areas not covered by cells, such as basements of buildings, due to the nature of the service, requiring wider coverage than other services provided by 5G communication systems. Terminals supporting mMTC must be composed of low-cost terminals, and since it is difficult to frequently replace the terminal's battery, they require a very long battery life time, such as 10 to 16 years.

[0060] Finally, URLLC refers to a cellular-based wireless communication service used for a specific purpose (mission-critical). For example, services can be considered for remote control of robots or machinery, industrial automation, unmanaged aerial vehicles, remote health care, or emergency alerts. Therefore, the communication provided by URLLC must provide very low latency and very high reliability. For example, a service supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds and, at the same time, must have a 10 -5The following packet error rate requirements must be met. Therefore, for services supporting URLLC, 5G systems must provide a smaller transmit time interval (TTI) than other services, while simultaneously allocating extensive resources in the frequency band to ensure communication link reliability.

[0061] The three services of the 5G communication system (hereinafter, "interoperable with 5G systems")—eMBB, URLLC, and mMTC—can be multiplexed and transmitted within a single system. To meet the different requirements of each service, different transmission and reception techniques and parameters can be used across the services.

[0062] The frame structure of the 5G system will be described in more detail below with reference to the drawings. For convenience of explanation, the wireless communication system to which the present disclosure applies will be described below using the configuration of a 5G system as an example. However, the embodiments of the present disclosure can be applied in the same or similar manner to systems beyond 5G or other communication systems to which the present disclosure applies.

[0063] FIG. 1 is a diagram illustrating a basic structure of a time-frequency domain, which is a wireless resource domain, in a wireless communication system according to one embodiment of the present disclosure.

[0064] In Fig. 1, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The basic unit of resources in the time and frequency domains is a resource element (RE, 101), which can be defined as one OFDM symbol (or DFT-s-OFDM (discrete Fourier transform spread OFDM) symbol) (102) in the time axis and one subcarrier (subcarrier, 103) in the frequency axis. In the frequency domain, the number of subcarriers per resource block (RB) is represented by (For example, 12) consecutive REs can form one resource block (RB, 104). In addition, the number of symbols per subframe according to the setting value μ for the subcarrier spacing in the time domain is indicated. A number of consecutive OFDM symbols can constitute one subframe (subframe, 110).

[0065] FIG. 2 is a diagram illustrating a slot structure considered in a wireless communication system according to one embodiment of the present disclosure.

[0066] FIG. 2 illustrates an example of a slot structure including a frame (200), a subframe (201), and slots (202, 203). One frame (200) can be defined as 10 ms. One subframe (201) can be defined as 1 ms, and thus one frame (200) can be composed of a total of 10 subframes (201). One slot (202, 203) can be defined as 14 OFDM symbols (i.e., the number of symbols per slot ( ))=14). One subframe (201) may be composed of one or more slots (202, 203), and the number of slots (202, 203) per one subframe (201) may vary depending on μ (204 or 205), which is a setting value for the subcarrier space (SCS).

[0067] The slot structure is illustrated when μ=0 (204) and μ=1 (205) as the subcarrier spacing setting value. When μ=0 (204), one subframe (201) can be composed of one slot (202), and when μ=1 (205), one subframe (201) can be composed of two slots (including slot (203) for example). That is, depending on the setting value μ for the subcarrier spacing, the number of slots per subframe ( )) may vary, and accordingly the number of slots per frame ( ) may vary. For example, depending on the subcarrier spacing setting μ and can be defined as shown in Table 1 below.

[0068] μ 0141011142022144043148084141601651432032

[0069] In a 5G communication system, a synchronization signal block (SSB, which may be used interchangeably with an SS block or an SS / PBCH block) may be transmitted for initial connection of a terminal, and the synchronization signal block may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH).

[0070] In the initial access phase where a terminal connects to the system, the terminal can first obtain downlink time and frequency domain synchronization from a synchronization signal through cell search and obtain a cell ID. The synchronization signal may include PSS and SSS. In addition, the terminal can obtain transmission-related system information and basic parameter values, such as system bandwidth or related control information, by receiving a PBCH that transmits a master information block (MIB) from a base station. Based on this information, the terminal can perform decoding on the physical downlink control channel (PDCCH) and the physical downlink shared channel (PDSCH) to obtain a system information block (SIB). Thereafter, the terminal can exchange identification-related information between the base station and the terminal through a random access phase and go through registration and authentication steps to initially access the network. Additionally, the terminal can obtain cell-common transmission and reception-related control information by receiving system information transmitted by the base station (which may be used interchangeably with SIB). 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.

[0071] 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.

[0072] FIG. 3 is a diagram illustrating an example of a time domain mapping structure and beam sweeping operation of a synchronization signal according to one embodiment of the present disclosure.

[0073] For the sake of explanation, the following components can be defined:

[0074] - PSS (primary synchronization signal): This signal serves as the basis for DL ​​time / frequency synchronization and provides some cell ID information.

[0075] - 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.

[0076] - PBCH: Provides MIB, 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.

[0077] - SS / PBCH block: 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.

[0078] Referring to FIG. 3, beam sweeping can be applied to SS / PBCH block units over time. Terminal 1 (305) receives an SS / PBCH block using a beam radiated in the direction of #d0 (303) by beamforming applied to SS / PBCH block #0 at time t1 (301). Terminal 2 (306) receives an SS / PBCH block using a beam radiated in the direction of #d4 (304) by beamforming applied to SS / PBCH block #4 at time t2 (302). 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, it may be difficult for terminal 1 (305) to obtain 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.

[0079] In addition to the initial connection procedure, the UE may also receive SS / PBCH blocks to determine whether the radio link quality of the current cell is maintained at a certain level. Furthermore, during a handover procedure, in which the UE moves from the current cell to a neighboring cell, the UE 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.

[0080] Below, the cell initial access operation procedure of a 5G wireless communication system will be described in more detail with reference to drawings.

[0081] Synchronization signals serve as a reference for cell search and can be transmitted with subcarrier spacing appropriate for the channel environment (e.g., phase noise) for each frequency band. 5G base stations can transmit multiple synchronization signal blocks depending on the number of analog beams they intend to operate. For example, PSS and SSS can be mapped and transmitted across 12 RBs, and PBCH can be mapped and transmitted across 24 RBs. The following describes the structure by which synchronization signals and PBCHs are transmitted in a 5G communication system.

[0082] FIG. 4 is a diagram illustrating a synchronization signal block considered in a wireless communication system according to one embodiment of the present disclosure.

[0083] Referring to FIG. 4, a synchronization signal block (SS block) (400) may include a PSS (401), an SSS (403), and a PBCH (402).

[0084] The synchronization signal block (400) can be mapped to four OFDM symbols (404) on the time axis. The PSS (401) and the SSS (403) can be transmitted in 12 RBs (405) on the frequency axis and in the first and third OFDM symbols on the time axis, respectively. In a 5G system, for example, a total of 1008 different cell IDs can be defined. Depending on the physical cell ID (PCI) of the cell, the PSS (401) can have three different values, and the SSS (403) can have 336 different values. The terminal can obtain one of (336 X 3 =) 1008 cell IDs by detecting the PSS (401) and the SSS (403) and combining them. This can be expressed by the following mathematical expression 1.

[0085] [Mathematical Formula 1]

[0086]

[0087] Here can be estimated from SSS(403) and can have a value between 0 and 335. can be estimated from PSS (401) and can have a value between 0 and 2. The terminal class Cell ID is a combination of The value can be estimated.

[0088] PBCH (402) can be transmitted in resources including 6 RBs (407, 408) on both sides, excluding 12 RBs (405) in the middle, while SSS (403) is transmitted in 24 RBs (406) in the frequency axis and in the 2nd to 4th OFDM symbols of the SS block in the time axis. PBCH (402) can include a PBCH payload and a PBCH DMRS (demodulation reference signal), and various system information called MIB can be transmitted in the PBCH payload. For example, MIB can include information as shown in Table 2 below.

[0089] MIB ::= SEQUENCE {systemFrameNumber BIT STRING (SIZE (6)),subCarrierSpacingCommon ENUMERATED {scs15or60, scs30or120},ssb-SubcarrierOffset INTEGER (0..15),dmrs-TypeA-Position ENUMERATED {pos2, pos3},pdcch-ConfigSIB1 PDCCH-ConfigSIB1,cellBarred ENUMERATED {barred, notBarred},intraFreqReselection ENUMERATED {allowed, notAllowed},spare BIT STRING (SIZE (1))}

[0090] - Synchronization signal block information: The frequency domain offset of the synchronization signal block can be indicated through the 4-bit ssb-SubcarrierOffset in the MIB. The index of the synchronization signal block including the PBCH can be indirectly obtained through decoding the PBCH DMRS and PBCH. In one embodiment, in a frequency band below 6 GHz, 3 bits obtained through decoding the PBCH DMRS indicate the synchronization signal block index, and in a frequency band above 6 GHz, a total of 6 bits, including 3 bits obtained through decoding the PBCH DMRS and 3 bits obtained through decoding the PBCH included in the PBCH payload, can indicate the synchronization signal block index including the PBCH.

[0091] - PDCCH (physical downlink control channel) configuration information: The subcarrier spacing of the common downlink control channel can be indicated through 1 bit (subCarrierSpacingCommon) in the MIB, and the time-frequency resource configuration information of the CORESET (control resource set) and search space (SS) can be indicated through 8 bits (pdcch-ConfigSIB1).

[0092] - SFN: Within the MIB, 6 bits (systemFrameNumber) can be used to indicate a portion of the SFN. The 4 least significant bits (LSBs) of the SFN are included in the PBCH payload, so the terminal can indirectly obtain them through PBCH decoding.

[0093] - Timing information within a radio frame: The terminal can indirectly determine whether the synchronization signal block was transmitted in the first or second half frame of the radio frame by using the synchronization signal block index described above and 1 bit (half frame) obtained through PBCH decoding included in the PBCH payload.

[0094] Since the transmission bandwidths (12 RB (405)) of PSS (401) and SSS (403) and the transmission bandwidth (24 RB (406)) of PBCH (402) are different from each other, in the first OFDM symbol in which PSS (401) is transmitted within the transmission bandwidth of PBCH (402), 6 RBs (407, 408) on both sides exist except for the 12 RBs in the middle in which PSS (401) is transmitted, and the above areas can be used to transmit other signals or can be empty.

[0095] Synchronization signal blocks can be transmitted using the same analog beam. For example, PSS (401), SSS (403), and PBCH (402) can all be transmitted using the same beam. Since analog beams have the characteristic that they cannot be applied differently in the frequency axis, the same analog beam can be applied to all frequency axis RBs within a specific OFDM symbol to which a specific analog beam is applied. For example, all four OFDM symbols in which PSS (401), SSS (403), and PBCH (402) are transmitted can be transmitted using the same analog beam.

[0096] FIG. 5 is a diagram illustrating an example of various transmissions of a synchronization signal block in a frequency band below 6 GHz considered in a wireless communication system according to one embodiment of the present disclosure.

[0097] Referring to FIG. 5, in a 5G communication system, in a frequency band of 6 GHz or less (or FR1 (frequency range 1), for example, 410 MHz-7125 MHz), a 15 kHz subcarrier spacing (SCS) (520) and a 30 kHz subcarrier spacing (530, 540) may be used for transmission of a synchronization signal block. In the 15 kHz subcarrier spacing (520), there may be one transmission case (e.g., case #1 (501)) for the synchronization signal block, and in the 30 kHz subcarrier spacing (530, 540), there may be two transmission cases (e.g., case #2 (502) and case #3 (503)) for the synchronization signal block.

[0098] In case #1 (501) at the subcarrier spacing of 15 kHz (520) in FIG. 5, a maximum of two synchronization signal blocks can be transmitted within 1 ms (504) (or equivalent to 1 slot length when 1 slot consists of 14 OFDM symbols). In the example of FIG. 4, synchronization signal block #0 (507) and synchronization signal block #1 (508) are illustrated. For example, synchronization signal block #0 (507) can be mapped to 4 consecutive symbols from the 3rd OFDM symbol, and synchronization signal block #1 (508) can be mapped to 4 consecutive symbols from the 9th OFDM symbol.

[0099] Different analog beams can be applied to synchronization signal block #0 (507) and synchronization signal block #1 (508). The same beam can be applied to all 3rd to 6th OFDM symbols to which synchronization signal block #0 (507) is mapped, and the same beam can be applied to all 9th ​​to 12th OFDM symbols to which synchronization signal block #1 (508) is mapped. In the 7th, 8th, 13th, and 14th OFDM symbols to which synchronization signal blocks are not mapped, the analog beam can be freely determined at the discretion of the base station as to which beam to use.

[0100] In case #2 (502) at the subcarrier spacing of 30 kHz (530) in FIG. 5, a maximum of two synchronization signal blocks can be transmitted within 0.5 ms (505) (or 1 slot length when 1 slot consists of 14 OFDM symbols), and accordingly, a maximum of four synchronization signal blocks can be transmitted within 1 ms (or 2 slot lengths when 1 slot consists of 14 OFDM symbols). In the example of FIG. 4, a case is illustrated where synchronization signal block #0 (509), synchronization signal block #1 (510), synchronization signal block #2 (511), and synchronization signal block #3 (512) are transmitted within 1 ms (i.e., two slots) of time. Synchronization signal block #0 (509) and synchronization signal block #1 (510) can be mapped from the 5th OFDM symbol and the 9th OFDM symbol of the first slot, respectively, and synchronization signal block #2 (511) and synchronization signal block #3 (512) can be mapped from the 3rd OFDM symbol and the 7th OFDM symbol of the second slot, respectively.

[0101] Different analog beams may be applied to synchronization signal block #0 (509), synchronization signal block #1 (510), synchronization signal block #2 (511), and synchronization signal block #3 (512), respectively. In addition, the same analog beam may be applied to the 5th to 8th OFDM symbols of the first slot in which synchronization signal block #0 (509) is transmitted, the 9th to 12th OFDM symbols of the first slot in which synchronization signal block #1 (510) is transmitted, the 3rd to 6th symbols of the second slot in which synchronization signal block #2 (511) is transmitted, and the 7th to 10th symbols of the second slot in which synchronization signal block #3 (512) is transmitted. In OFDM symbols in which synchronization signal blocks are not mapped, the analog beam may be freely determined at the discretion of the base station as to which beam to use.

[0102] In case #3 (503) at subcarrier spacing of 30 kHz (540) in FIG. 5, a maximum of two synchronization signal blocks can be transmitted within 0.5 ms (506) (or 1 slot length when 1 slot consists of 14 OFDM symbols), and accordingly, a maximum of four synchronization signal blocks can be transmitted within 1 ms (or 2 slot lengths when 1 slot consists of 14 OFDM symbols). In the example of FIG. 4, synchronization signal block #0 (513), synchronization signal block #1 (514), synchronization signal block #2 (515), and synchronization signal block #3 (516) are illustrated as being transmitted within 1 ms (i.e., two slots) of time. Synchronization signal block #0 (513) and synchronization signal block #1 (514) can be mapped from the 3rd OFDM symbol and the 9th OFDM symbol of the first slot, respectively, and synchronization signal block #2 (515) and synchronization signal block #3 (516) can be mapped from the 3rd OFDM symbol and the 9th OFDM symbol of the second slot, respectively.

[0103] Different analog beams may be used for synchronization signal block #0 (513), synchronization signal block #1 (514), synchronization signal block #2 (515), and synchronization signal block #3 (516), respectively. As described in the examples above, the same analog beam may be used in all four OFDM symbols in which each synchronization signal block is transmitted, and the base station may freely determine which beam to use in OFDM symbols to which no synchronization signal block is mapped.

[0104] FIG. 6 is a diagram illustrating an example of transmission of a synchronization signal block in a frequency band of 6 GHz or higher considered in a wireless communication system according to one embodiment of the present disclosure.

[0105] Referring to FIG. 6, in a wireless communication system, in a frequency band of 6 GHz or higher (or FR2, for example, 24250 MHz-52600 MHz), a subcarrier spacing of 120 kHz (630) as in the example of Case #4 (610) and a subcarrier spacing of 240 kHz (640) as in the example of Case #5 (620) may be used for transmission of a synchronization signal block.

[0106] In case #4 (610) with a subcarrier spacing of 120 kHz (630), up to four synchronization signal blocks can be transmitted within a time period of 0.25 ms (601) (or equivalent to two slot lengths when one slot consists of 14 OFDM symbols). In the example of Fig. 6, synchronization signal block #0 (603), synchronization signal block #1 (604), synchronization signal block #2 (605), and synchronization signal block #3 (606) are illustrated as being transmitted within 0.25 ms (i.e., two slots). Synchronization signal block #0 (603) and synchronization signal block #1 (604) can be mapped to 4 consecutive symbols starting from the 5th OFDM symbol of the first slot, and to 4 consecutive symbols starting from the 9th OFDM symbol, respectively, and synchronization signal block #2 (605) and synchronization signal block #3 (606) can be mapped to 4 consecutive symbols starting from the 3rd OFDM symbol of the second slot, and to 4 consecutive symbols starting from the 7th OFDM symbol, respectively.

[0107] As described in the above embodiment, different analog beams may be used for synchronization signal block #0 (603), synchronization signal block #1 (604), synchronization signal block #2 (605), and synchronization signal block #3 (606), respectively. In addition, the same analog beam may be used in all four OFDM symbols in which each synchronization signal block is transmitted, and in OFDM symbols to which no synchronization signal block is mapped, the beam to be used may be freely determined at the discretion of the base station.

[0108] In case #5 (620) at subcarrier spacing of 240 kHz (640), up to 8 synchronization signal blocks can be transmitted within 0.25 ms (602) (or 4 slot length when 1 slot consists of 14 OFDM symbols). In the example of Fig. 6, synchronization signal block #0 (607), synchronization signal block #1 (608), synchronization signal block #2 (609), synchronization signal block #3 (610), synchronization signal block #4 (611), synchronization signal block #5 (612), synchronization signal block #6 (613), and synchronization signal block #7 (614) are illustrated as being transmitted within 0.25 ms (i.e. 4 slots).

[0109] Synchronization signal block #0 (607) and synchronization signal block #1 (608) can be mapped to 4 consecutive symbols from the 9th OFDM symbol of the first slot, and 4 consecutive symbols from the 13th OFDM symbol, respectively; synchronization signal block #2 (609) and synchronization signal block #3 (610) can be mapped to 4 consecutive symbols from the 3rd OFDM symbol of the second slot, and 4 consecutive symbols from the 7th OFDM symbol, respectively; synchronization signal block #4 (611), synchronization signal block #5 (612), and synchronization signal block #6 (613) can be mapped to 4 consecutive symbols from the 5th OFDM symbol of the third slot, and 4 consecutive symbols from the 9th OFDM symbol, and 4 consecutive symbols from the 13th OFDM symbol, respectively; synchronization signal block #7 (614) can be mapped to 4 consecutive symbols from the 4th slot, and 4 consecutive symbols from the 9th OFDM symbol, respectively; It can be mapped to four consecutive symbols starting from the third OFDM symbol.

[0110] As described in the above embodiment, different analog beams may be used for synchronization signal block #0 (607), synchronization signal block #1 (608), synchronization signal block #2 (609), synchronization signal block #3 (610), synchronization signal block #4 (611), synchronization signal block #5 (612), synchronization signal block #6 (613), and synchronization signal block #7 (614), respectively. In addition, the same analog beam may be used in all four OFDM symbols in which each synchronization signal block is transmitted, and in OFDM symbols to which the synchronization signal block is not mapped, which beam to be used may be freely determined at the discretion of the base station.

[0111] FIG. 7 is a diagram illustrating an example of transmission of a synchronization signal block according to a subcarrier interval within 5 ms in a wireless communication system according to an embodiment of the present disclosure.

[0112] Referring to FIG. 7, in a 5G communication system, a synchronization signal block may be periodically transmitted in units of, for example, a time interval (710) of 5 ms (corresponding to 5 subframes or half frames).

[0113] In frequency bands below 3 GHz, up to four synchronization signal blocks can be transmitted within a 5 ms (710) period. In frequency bands exceeding 3 GHz and below 6 GHz, up to eight synchronization signal blocks can be transmitted. In frequency bands above 6 GHz, up to 64 synchronization signal blocks can be transmitted. As described above, subcarrier spacings of 15 kHz and 30 kHz can be used in frequencies below 6 GHz.

[0114] In the example of FIG. 7, in case #1 (501) of FIG. 5, which consists of one slot and has a subcarrier spacing of 15 kHz, synchronization signal blocks can be mapped to the first and second slots in a frequency band of 3 GHz or less, so that up to 4 (721) can be transmitted, and in the frequency band of more than 3 GHz and less than 6 GHz, synchronization signal blocks can be mapped to the first, second, third, and fourth slots, so that up to 8 (722) can be transmitted. In case #2 (502) or case #3 (503) with a subcarrier spacing of 30 kHz and consisting of two slots of FIG. 5, synchronization signal blocks can be mapped starting from the first slot in a frequency band of 3 GHz or less, so that up to 4 (731, 741) can be transmitted, and in a frequency band exceeding 3 GHz and below 6 GHz, synchronization signal blocks can be mapped starting from the first and third slots, so that up to 8 (732, 742) can be transmitted.

[0115] Subcarrier spacings of 120 kHz and 240 kHz can be used in frequencies exceeding 6 GHz. In the example of Fig. 7, in case #4 (610) with subcarrier spacing of 120 kHz consisting of two slots of Fig. 6, synchronization signal blocks in the frequency band exceeding 6 GHz can be mapped starting from the 1st, 3rd, 5th, 7th, 11th, 13th, 15th, 17th, 21st, 23rd, 25th, 27th, 31st, 33rd, 35th, and 37th slots, so that up to 64 (751) can be transmitted. In the example of FIG. 7, in case #5 (620) of FIG. 6, which consists of 4 slots and has a subcarrier spacing of 240 kHz, synchronization signal blocks in a frequency band exceeding 6 GHz can be mapped starting from the 1st, 5th, 9th, 13th, 21st, 25th, 29th, and 33rd slots, so that up to 64 (761) can be transmitted.

[0116] The terminal can decode the PDCCH and PDSCH based on the system information included in the received MIB and then acquire the SIB. The SIB may include at least one of uplink cell bandwidth-related information, random access parameters, paging parameters, or parameters related to uplink power control.

[0117] Typically, a terminal can establish a wireless link with a network through a random access procedure based on synchronization with the network and system information acquired during the cell search process. Random access can be either contention-based or contention-free. When a terminal performs cell selection and reselection during the initial cell access phase, for example, contention-based random access can be used to transition from the RRC_IDLE state to the RRC_CONNECTED state. Contention-free random access can be used to reestablish uplink synchronization when downlink data arrives, in the case of a handover, or for positioning. Table 3 below illustrates the conditions (events) that trigger the random access procedure in a 5G system.

[0118] - Initial access from RRC_IDLE;- RRC Connection Re-establishment procedure;- DL or UL data arrival during RRC_CONNECTED when UL synchronization status is "non-synchronised";- UL data arrival during RRC_CONNECTED when there are no PUCCH resources for SR available;- SR failure;- Request by RRC upon synchronous reconfiguration (e.g. handover);- RRC Connection Resume procedure from RRC_INACTIVE;- To establish time alignment for a secondary TAG;- Request for Other SI;- Beam failure recovery;- Consistent UL LBT failure on SpCell.

[0119] Below, a method for setting a measurement time for radio resource management (RRM) based on a synchronization signal block (SS block or SSB) of a 5G wireless communication system is described.

[0120] The terminal receives MeasObjectNR in MeasObjectToAddModList through upper-layer signaling for SSB-based intra / inter-frequency measurements and CSI-RS (channel state information-reference signal)-based intra / inter-frequency measurements. For example, MeasObjectNR can be configured as shown in Table 4 below.

[0121] MeasObjectNR ::= SEQUENCE {ssbFrequency ARFCN-ValueNR OPTIONAL, -- Cond SSBorAssociatedSSBssbSubcarrierSpacing SubcarrierSpacing OPTIONAL, -- Cond SSBorAssociatedSSBsmtc1 SSB-MTC OPTIONAL, -- Cond SSBorAssociatedSSBsmtc2 SSB-MTC2 OPTIONAL, -- Cond IntraFreqConnectedrefFreqCSI-RS ARFCN-ValueNR OPTIONAL, -- Cond CSI-RSreferenceSignalConfig ReferenceSignalConfig,absThreshSS-BlocksConsolidation ThresholdNR OPTIONAL, -- Need RabsThreshCSI-RS-Consolidation ThresholdNR OPTIONAL, -- Need RnrofSS-BlocksToAverage INTEGER (2..maxNrofSS-BlocksToAverage) OPTIONAL, -- Need RnrofCSI-RS-ResourcesToAverage INTEGER (2..maxNrofCSI-RS-ResourcesToAverage) OPTIONAL, -- Need RquantityConfigIndex INTEGER (1..maxNrofQuantityConfig),offsetMO Q-OffsetRangeList,cellsToRemoveList PCI-List OPTIONAL, -- Need NcellsToAddModList CellsToAddModList OPTIONAL, -- Need NblackCellsToRemoveList PCI-RangeIndexList OPTIONAL, -- Need NblackCellsToAddModList SEQUENCE (SIZE (1..maxNrofPCI-Ranges)) OF PCI-RangeElement OPTIONAL, -- Need NwhiteCellsToRemoveList PCI-RangeIndexList OPTIONAL, -- Need NwhiteCellsToAddModList SEQUENCE (SIZE (1..maxNrofPCI-Ranges)) OF PCI-RangeElement OPTIONAL, -- Need N...,[[freqBandIndicatorNR FreqBandIndicatorNR OPTIONAL, -- Need RmeasCycleSCell ENUMERATED {sf160, sf256, sf320, sf512, sf640, sf1024, sf1280} OPTIONAL -- Need R]],[[smtc3list-r16 SSB-MTC3List-r16 OPTIONAL, -- Need Rrmtc-Config-r16 SetupRelease {RMTC-Config-r16} OPTIONAL, -- Need Mt312-r16 SetupRelease { T312-r16} OPTIONAL -- Need M]]}.

[0122] The terms in Table 4 can perform the following functions, but are not limited thereto.

[0123] - ssbFrequency: You can set the frequency of the synchronization signal related to MeasObjectNR.

[0124] - ssbSubcarrierSpacing: Sets the subcarrier spacing of SSB. FR1 can only be applied to 15 kHz or 30 kHz, and FR2 can only be applied to 120 kHz or 240 kHz.

[0125] - smtc1: Indicates SS / PBCH block measurement timing configuration, and can set the primary measurement timing configuration and the timing offset and duration for SSB.

[0126] - smtc2: You can set the secondary measurement timing configuration for the SSB associated with the MeasObjectNR having the PCI listed in pci-List.

[0127] In addition to this, SMTC can be configured to the UE through other higher layer signaling, for example, SIB2 for intra-frequency, inter-frequency and inter-RAT cell reselection, or reconfigurationWithSync for NR PSCell (primary secondary cell) change and NR PCell (primary cell) change, and also through SCellConfig for NR SCell (secondary cell) addition.

[0128] For SSB measurement, the terminal can set the first SS / PBCH block measurement timing configuration (SMTC) according to periodictiyAndOffset (providing period and offset) through smtc1 set through upper layer signaling. In one embodiment, the first subframe of each SMTC occasion can start from the subframe of SFN and SpCell that satisfy the conditions of Table 5 below.

[0129] SFN mod T = (FLOOR (Offset / 10));if the Periodicity is larger than sf5:subframe = Offset mod 10;else:subframe = Offset or (Offset +5);with T = CEIL(Periodicity / 10).

[0130] If smtc2 is configured, the terminal can configure additional SMTCs according to the configured smtc2 periodicity and the offset and duration of smtc1 for the cells indicated by the pci-List value of smtc2 in the same MeasObjectNR. In addition, the terminal can configure smtc and measure SSB through smtc2-LP (with long periodicity) and smtc3list for IAB-MT (integrated access and backhaul - mobile termination) on the same frequency (e.g., frequency for intra-frequency cell reselection) or on different frequencies (e.g., frequencies for inter-frequency cell reselection). In one embodiment, the terminal may not consider SSB transmitted in subframes other than SMTC occasions for SSB-based RRM measurement at the configured ssbFrequency.

[0131] Next, we will specifically explain DMRS, one of the reference signals in the 5G system.

[0132] A DMRS can be composed of multiple DMRS ports, and each port maintains orthogonality to avoid interference with each other by using code division multiplexing (CDM) or frequency division multiplexing (FDM). However, the term for DMRS can be expressed with different terms depending on the user's intention and the purpose of use of the reference signal. The term DMRS is only used to easily explain the technical content of the present disclosure and to provide a specific example to help understand the present disclosure, and is not intended to limit the scope of the present disclosure. In other words, it is obvious to a person skilled in the art to which the present disclosure pertains that the technical idea of ​​the present disclosure can be implemented for any reference signal.

[0133] FIG. 8 is a diagram illustrating an example of DMRS patterns (type 1 and type 2) used for communication between a base station and a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0134] In a 5G system, two DMRS patterns can be supported. Referring to Fig. 8, DMRS type 1 (801, 802) is illustrated, specifically, a 1-symbol pattern (801) and a 2-symbol pattern (802). DMRS type 1 (801, 802) is a DMRS pattern with a comb 2 structure and can be composed of two CDM groups, and different CDM groups can be FDM.

[0135] In the 1 symbol pattern (801), CDM in frequency may be applied to the same CDM group, so that two DMRS ports may be distinguished, and thus a total of four orthogonal DMRS ports may be configured. The 1 symbol pattern (801) may include a DMRS port ID mapped to each CDM group (the DMRS port ID for downlink may be indicated by the illustrated number + 1000). In the 2 symbol pattern (802), CDM in time / frequency may be applied to the same CDM group, so that four DMRS ports may be distinguished, and thus a total of eight orthogonal DMRS ports may be configured. The 2 symbol pattern (802) may include a DMRS port ID mapped to each CDM group (the DMRS port ID for downlink may be indicated by the illustrated number + 1000).

[0136] Referring to FIG. 8, DMRS type 2 (803, 804) is illustrated, which is a DMRS pattern having a structure in which FD-OCC (frequency domain orthogonal cover codes) are applied to frequency-adjacent subcarriers, and can be composed of three CDM groups, and different CDM groups can be FDMed.

[0137] In the 1 symbol pattern (803), frequency-based CDM is applied to the same CDM group to distinguish two DMRS ports, and thus a total of six orthogonal DMRS ports can be configured. The 1 symbol pattern (803) may include a DMRS port ID mapped to each CDM group (the DMRS port ID for downlink may be indicated by the illustrated number + 1000). In the 2 symbol pattern (704), time / frequency-based CDM is applied to the same CDM group to distinguish four DMRS ports, and thus a total of twelve orthogonal DMRS ports can be configured. The 2 symbol pattern (804) may include a DMRS port ID mapped to each CDM group (the DMRS port ID for downlink may be indicated by the illustrated number + 1000).

[0138] As described above, in the NR system, two different DMRS patterns (e.g., DMRS type 1 (801, 802) or DMRS type 2 (803, 804)) can be configured, and it can also be configured whether each DMRS pattern is a one symbol pattern (801, 803) or two adjacent symbol patterns (802, 804). In addition, in the NR system, not only the DMRS port number is scheduled, but also the number of CDM groups scheduled together for PDSCH rate matching can be configured and signaled. In addition, in the case of CP-OFDM (cyclic prefix based orthogonal frequency division multiplex), both of the above-described DMRS patterns can be supported in the DL and UL, while in the case of DFT-S-OFDM, only DMRS type 1 (801, 802) among the above-described DMRS patterns can be supported in the UL.

[0139] Additionally, support may be provided for configuring additional DMRS. Front-loaded DMRS refers to the first DMRS transmitted and received in the frontmost symbol in the time domain among DMRSs, and additional DMRS refers to DMRS transmitted and received in the symbol after the front-loaded DMRS in the time domain. In the NR system, the number of additional DMRSs can be set from a minimum of 0 to a maximum of 3. Additionally, when additional DMRSs are configured, the same pattern as the front-loaded DMRS may be assumed. In one embodiment, when information on whether the DMRS pattern type described above is type 1 or type 2, information on whether the DMRS pattern is a one-symbol pattern or an adjacent two-symbol pattern, and information on the number of CDM groups used with the DMRS port are indicated for the front-loaded DMRS, when additional DMRSs are additionally configured, it may be assumed that the additional DMRSs have the same DMRS information as the front-loaded DMRSs.

[0140] In one embodiment, the downlink DMRS settings described above can be set via RRC signaling as shown in Table 6 below.

[0141] DMRS-DownlinkConfig ::= SEQUENCE {dmrs-Type ENUMERATED {type2} OPTIONAL, -- Need Sdmrs-AdditionalPosition ENUMERATED {pos0, pos1, pos3} OPTIONAL, -- Need SmaxLength ENUMERATED {len2} OPTIONAL, -- Need SscramblingID0 INTEGER (0..65535) OPTIONAL, -- Need SscramblingID1 INTEGER (0..65535) OPTIONAL, -- Need SphaseTrackingRS SetupRelease {PTRS-DownlinkConfig} OPTIONAL, -- Need M...}

[0142] Here, dmrs-Type can set the DMRS type, dmrs-AdditionalPosition can set additional DMRS OFDM symbols, maxLength can set a 1 symbol DMRS pattern or a 2 symbol DMRS pattern, scramblingID0 and scramblingID1 can set scrambling IDs, and phaseTrackingRS can set PTRS (phase tracking reference signal).

[0143] Additionally, the above-mentioned uplink DMRS settings can be set via RRC signaling as shown in Table 7 below.

[0144] DMRS-UplinkConfig ::= SEQUENCE {dmrs-Type ENUMERATED {type2} OPTIONAL, -- Need Sdmrs-AdditionalPosition ENUMERATED {pos0, pos1, pos3} OPTIONAL, -- Need RphaseTrackingRS SetupRelease { PTRS-UplinkConfig} OPTIONAL, -- Need MmaxLength ENUMERATED {len2} OPTIONAL, -- Need StransformPrecodingDisabled SEQUENCE {scramblingID0 INTEGER (0..65535) OPTIONAL, -- Need SscramblingID1 INTEGER (0..65535) OPTIONAL, -- Need S...} OPTIONAL, -- Need RtransformPrecodingEnabled SEQUENCE {nPUSCH-Identity INTEGER (0..1007) OPTIONAL, -- Need SsequenceGroupHopping ENUMERATED {disabled} OPTIONAL, -- Need SsequenceHopping ENUMERATED {enabled} OPTIONAL, -- Need S...} OPTIONAL, -- Need R...}

[0145] Here, dmrs-Type can set the DMRS type, dmrs-AdditionalPosition (additional DMRS OFDM symbols can be set), phaseTrackingRS can set PTRS, maxLength can set 1 symbol DMRS pattern or 2 symbol DMRS pattern, scramblingID0 and scramblingID1 can set scrambling ID0s, nPUSCH-Identity can set cell ID for DFT-s-OFDM, sequenceGroupHopping can disable sequence group hopping, and sequenceHopping can enable sequence hopping.

[0146] FIG. 9 is a diagram illustrating an example of channel estimation using DMRS received in one PUSCH in a time band of a wireless communication system according to one embodiment of the present disclosure.

[0147] Referring to Fig. 9, when performing channel estimation for data decoding using DMRS, channel estimation can be performed within a PRG (precoding resource block group), which is a bundling unit, by bundling physical resource blocks (PRBs) linked to the system band in the frequency band. In addition, in the time unit, the channel can be estimated by assuming that only DMRSs received on one PUSCH have the same precoding.

[0148] Below, we describe a time domain resource allocation (TDRA) method for data channels in a 5G communication system. A base station can configure a time domain resource allocation information table for a downlink data channel (PDSCH) and an uplink data channel (physical uplink shared channel, PUSCH) to a terminal through higher layer signaling (e.g., RRC signaling).

[0149] The base station may set a table with a maximum of maxNrofDL-Allocations=17 entries for PDSCH, and may set a table with a maximum of maxNrofUL-Allocations=17 entries for PUSCH. The time domain resource allocation information may include, for example, at least one of PDCCH-to-PDSCH slot timing (corresponding to a slot-unit time interval between a time point when a PDCCH is received and a time point when a PDSCH scheduled by the received PDCCH is transmitted, denoted as K0) or PDCCH-to-PUSCH slot timing (corresponding to a slot-unit time interval between a time point when a PDCCH is received and a time point when a PUSCH scheduled by the received PDCCH is transmitted, denoted as K2), information on the position and length of a start symbol on which a PDSCH or PUSCH is scheduled within a slot, and a mapping type of a PDSCH or PUSCH.

[0150] In one embodiment, time domain resource allocation information for PDSCH can be set to a terminal through RRC signaling as shown in Table 8 below.

[0151] PDSCH-TimeDomainResourceAllocationList information elementPDSCH-TimeDomainResourceAllocationList ::= SEQUENCE (SIZE(1..maxNrofDL-Allocations)) OF PDSCH-TimeDomainResourceAllocationPDSCH-TimeDomainResourceAllocation ::= SEQUENCE {k0 INTEGER(0..32) OPTIONAL, -- Need SmappingType ENUMERATED {typeA, typeB},startSymbolAndLength INTEGER (0..127)repetitionNumber ENUMERATED {n2, n3, n4, n5, n6, n7, n8, n16} OPTIONAL, -- Cond Formats1-0and1-1}

[0152] Here, k0 represents the PDCCH-to-PDSCH timing (i.e., the slot offset between the DCI and the scheduled PDSCH) in slot units, mappingType represents the PDSCH mapping type, startSymbolAndLength represents the start symbol and length of the PDSCH, and repetitionNumber can represent the number of PDSCH transmission occasions according to the slot-based repetition method.

[0153] In one embodiment, time domain resource allocation information for PUSCH can be set to a terminal through RRC signaling as shown in Table 9 below.

[0154] PUSCH-TimeDomainResourceAllocation information elementPUSCH-TimeDomainResourceAllocationList ::= SEQUENCE (SIZE(1..maxNrofUL-Allocations)) OF PUSCH-TimeDomainResourceAllocationPUSCH-TimeDomainResourceAllocation ::= SEQUENCE {k2 INTEGER(0..32) OPTIONAL, -- Need SmappingType ENUMERATED {typeA, typeB},startSymbolAndLength INTEGER (0..127)}PUSCH-Allocation-r16 ::= SEQUENCE {mappingType-r16 ENUMERATED {typeA, typeB} OPTIONAL, -- Cond NotFormat01-02-Or-TypeAstartSymbolAndLength-r16 INTEGER (0..127) OPTIONAL, -- Cond NotFormat01-02-Or-TypeAstartSymbol-r16 INTEGER (0..13) OPTIONAL, -- Cond RepTypeBlength-r16 INTEGER (1..14) OPTIONAL, -- Cond RepTypeBnumberOfRepetitions-r16 ENUMERATED {n1, n2, n3, n4, n7, n8, n12, n16} OPTIONAL, -- Cond Format01-02...}

[0155] Here, k2 represents the PDCCH-to-PUSCH timing (i.e., the slot offset between the DCI and the scheduled PUSCH) in slot units, mappingType represents the PUSCH mapping type, startSymbolAndLength or StartSymbol and length represent the start symbol and length of the PUSCH, and numberOfRepetitions may represent the number of repetitions applied to the PUSCH transmission.

[0156] The base station may indicate to the terminal at least one entry in the table for time domain resource allocation information via L1 signaling (e.g., downlink control information (DCI)) (e.g., by using the 'time domain resource allocation' field in the DCI). The terminal may obtain time domain resource allocation information for the PDSCH or PUSCH based on the DCI received from the base station.

[0157] The following describes PUSCH transmission in a 5G system. PUSCH transmission can be dynamically scheduled by an UL grant in DCI (e.g., referred to as DG (dynamic grant)-PUSCH) or by configured grant Type 1 or configured grant Type 2 (e.g., referred to as CG (configured grant)-PUSCH). Dynamic scheduling for PUSCH transmission can be indicated, for example, by DCI format 0_0 or 0_1.

[0158] PUSCH transmission of Configured Grant Type 1 can be semi-statically scheduled by receiving configuredGrantConfig containing rrc-ConfiguredUplinkGrant of Table 10 via higher layer signaling, without receiving UL grant in DCI. PUSCH transmission of Configured Grant Type 2 can be semi-persistently scheduled by UL grant in DCI after receiving configuredGrantConfig not containing rrc-ConfiguredUplinkGrant of Table 10 via higher layer signaling.

[0159] In one embodiment, when PUSCH transmission is scheduled by configured grant, parameters applied to PUSCH transmission can be configured through configuredGrantConfig, which is a higher layer signaling of Table 10, except for certain parameters (e.g., dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, or scaling of UCI-OnPUSCH) provided by pusch-Config, which is a higher layer signaling of Table 11. For example, if a UE is provided with transformPrecoder in configuredGrantConfig, which is a higher layer signaling of Table 10, the UE can apply tp-pi2BPSK in pusch-Config of Table 11 for PUSCH transmission operated by configured grant.

[0160] ConfiguredGrantConfig ::= SEQUENCE {frequencyHopping ENUMERATED {intraSlot, interSlot} OPTIONAL, -- Need S,cg-DMRS-Configuration DMRS-UplinkConfig,mcs-Table ENUMERATED {qam256, qam64LowSE} OPTIONAL, -- Need Smcs-TableTransformPrecoder ENUMERATED {qam256, qam64LowSE} OPTIONAL, -- Need Suci-OnPUSCH SetupRelease { CG-UCI-OnPUSCH} OPTIONAL, -- Need MresourceAllocation ENUMERATED { resourceAllocationType0, resourceAllocationType1, dynamicSwitch},rbg-Size ENUMERATED {config2} OPTIONAL, -- Need SpowerControlLoopToUse ENUMERATED {n0, n1},p0-PUSCH-Alpha P0-PUSCH-AlphaSetId,transformPrecoder ENUMERATED {enabled, disabled} OPTIONAL, -- Need SnrofHARQ-Processes INTEGER(1..16),repK ENUMERATED {n1, n2, n4, n8},repK-RV ENUMERATED {s1-0231, s2-0303, s3-0000} OPTIONAL, -- Need Rperiodicity ENUMERATED {sym2, sym7, sym1x14, sym2x14, sym4x14, sym5x14, sym8x14, sym10x14, sym16x14, sym20x14,sym32x14, sym40x14, sym64x14, sym80x14, sym128x14, sym160x14, sym256x14, sym320x14, sym512x14,sym640x14, sym1024x14, sym1280x14, sym2560x14, sym5120x14,sym6, sym1x12, sym2x12, sym4x12, sym5x12, sym8x12, sym10x12, sym16x12, sym20x12, sym32x12,sym40x12, sym64x12, sym80x12, sym128x12, sym160x12, sym256x12, sym320x12, sym512x12, sym640x12,sym1280x12, sym2560x12},configuredGrantTimer INTEGER (1..64) OPTIONAL, -- Need Rrrc-ConfiguredUplinkGrant SEQUENCE {timeDomainOffset INTEGER (0..5119),timeDomainAllocation INTEGER (0..15),frequencyDomainAllocation BIT STRING (SIZE(18)),antennaPort INTEGER (0..31),dmrs-SeqInitialization INTEGER (0..1) OPTIONAL, -- Need RprecodingAndNumberOfLayers INTEGER (0..63),srs-ResourceIndicator INTEGER (0..15) OPTIONAL, -- Need RmcsAndTBS INTEGER (0..31),frequencyHoppingOffset INTEGER (1.. maxNrofPhysicalResourceBlocks-1) OPTIONAL, -- Need RpathlossReferenceIndex INTEGER (0..maxNrofPUSCH-PathlossReferenceRSs-1),...} OPTIONAL, -- Need R...}.

[0161] Next, the PUSCH transmission method is described. The DMRS antenna port for PUSCH transmission can be the same as the antenna port for SRS transmission. PUSCH transmission can follow a codebook-based transmission method or a non-codebook-based transmission method, respectively, depending on whether the value of txConfig in the pusch-Config of Table 11, which is a higher layer signaling, is 'codebook' or 'nonCodebook'. As described above, PUSCH transmission can be dynamically scheduled through DCI format 0_0 or 0_1, and can be semi-statically set by a configured grant.

[0162] If the UE is instructed to schedule PUSCH transmission via DCI format 0_0, the UE may perform beam configuration for PUSCH transmission using pucch-spatialRelationInfoID corresponding to a UE-specific, dedicated PUCCH resource with the lowest ID within an activated uplink bandwidth part (BWP) within the serving cell. In one embodiment, PUSCH transmission may be performed based on a single antenna port. The UE may not expect scheduling for PUSCH transmission via DCI format 0_0 within a BWP where a PUCCH resource including pucch-spatialRelationInfo is not configured. If the UE has not configured txConfig in pusch-Config of Table 11, the UE may not expect to be scheduled with DCI format 0_1.

[0163] PUSCH-Config ::= SEQUENCE {dataScramblingIdentityPUSCH INTEGER (0..1023) OPTIONAL, -- Need StxConfig ENUMERATED {codebook, nonCodebook} OPTIONAL, -- Need Sdmrs-UplinkForPUSCH-MappingTypeA SetupRelease { DMRS-UplinkConfig} OPTIONAL, -- Need Mdmrs-UplinkForPUSCH-MappingTypeB SetupRelease { DMRS-UplinkConfig} OPTIONAL, -- Need Mpusch-PowerControl PUSCH-PowerControl OPTIONAL, -- Need MfrequencyHopping ENUMERATED {intraSlot, interSlot} OPTIONAL, -- Need SfrequencyHoppingOffsetLists SEQUENCE (SIZE (1..4)) OF INTEGER (1..maxNrofPhysicalResourceBlocks-1)OPTIONAL, -- Need MresourceAllocation ENUMERATED { resourceAllocationType0, resourceAllocationType1, dynamicSwitch},pusch-TimeDomainAllocationList SetupRelease { PUSCH-TimeDomainResourceAllocationList} OPTIONAL, -- Need Mpusch-AggregationFactor ENUMERATED { n2, n4, n8} OPTIONAL, -- Need Smcs-Table ENUMERATED {qam256, qam64LowSE} OPTIONAL, -- Need Smcs-TableTransformPrecoder ENUMERATED {qam256, qam64LowSE} OPTIONAL, -- Need StransformPrecoder ENUMERATED {enabled, disabled} OPTIONAL, -- Need ScodebookSubset ENUMERATED {fullyAndPartialAndNonCoherent, partialAndNonCoherent,nonCoherent}OPTIONAL, -- Cond codebookBasedmaxRank INTEGER (1..4) OPTIONAL, -- Cond codebookBasedrbg-Size ENUMERATED { config2} OPTIONAL, -- Need Suci-OnPUSCH SetupRelease { UCI-OnPUSCH} OPTIONAL, -- Need Mtp-pi2BPSK ENUMERATED {enabled} OPTIONAL, -- Need S...}.

[0164] Next, we describe codebook-based PUSCH transmission. Codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1, and can operate semi-statically based on a configured grant. When codebook-based PUSCH transmission is dynamically scheduled via DCI format 0_1 ​​or semi-statically set via a configured grant, the UE can determine a precoder for PUSCH transmission based on the SRS resource indicator (SRI), the transmission precoding matrix indicator (TPMI), and the transmission rank (the number of PUSCH transmission layers).

[0165] According to one embodiment of the present disclosure, the SRI may be given through a field SRS resource indicator in the DCI or configured through a higher layer signaling srs-ResourceIndicator. The UE may be configured with at least one SRS resource when transmitting a codebook-based PUSCH, and for example, may be configured with up to two SRS resources. When the UE receives the SRI through the DCI, the SRS resource indicated by the SRI may refer to an SRS resource corresponding to the SRI among the SRS resources transmitted before the PDCCH including the SRI. In addition, the TPMI and the transmission rank may be given through the fields precoding information and number of layers in the DCI or configured through a higher layer signaling precodingAndNumberOfLayers. The TPMI may be used to indicate a precoder applied to the PUSCH transmission.

[0166] A precoder to be used for PUSCH transmission can be selected from an uplink codebook having the same number of antenna ports as the nrofSRS-Ports value in SRS-Config, which is a higher layer signaling. In codebook-based PUSCH transmission, the UE can determine a codebook subset based on the TPMI and codebookSubset in pusch-Config, which is a higher layer signaling. In one embodiment, the codebookSubset in pusch-Config, which is a higher layer signaling, can be set to one of 'fullyAndPartialAndNonCoherent', 'partialAndNonCoherent', or 'nonCoherent' based on the UE capability that the UE reports to the base station.

[0167] If the UE reports 'partialAndNonCoherent' as the UE capability, the UE may not expect the value of codebookSubset, which is a higher layer signaling, to be set to 'fullyAndPartialAndNonCoherent'. Also, if the UE reports 'nonCoherent' as the UE capability, the UE may not expect the value of codebookSubset, which is a higher layer signaling, to be set to 'fullyAndPartialAndNonCoherent' or 'partialAndNonCoherent'. If nrofSRS-Ports in SRS-ResourceSet, which is a higher layer signaling, indicates two SRS antenna ports, the UE may not expect the value of codebookSubset, which is a higher layer signaling, to be set to 'partialAndNonCoherent'.

[0168] A terminal can be configured with one SRS resource set in which the usage value in the upper layer signaling SRS-ResourceSet is set to 'codebook', and one SRS resource in the corresponding SRS resource set can be indicated via SRI. If multiple SRS resources are configured in an SRS resource set in which the usage value in the upper layer signaling SRS-ResourceSet is set to 'codebook', the terminal can expect that the value of nrofSRS-Ports in the upper layer signaling SRS-Resource is set to the same value for all SRS resources.

[0169] The terminal transmits one or more SRS resources included in an SRS resource set in which the usage value is set to 'codebook' according to upper layer signaling to the base station, and the base station can select one of the SRS resources transmitted by the terminal and instruct the terminal to perform PUSCH transmission using transmission beam information of the corresponding SRS resource. In one embodiment, in codebook-based PUSCH transmission, the SRI is used as information for selecting an index of one SRS resource and can be included in the DCI. Additionally, the base station can transmit information indicating a TPMI and rank to be used by the terminal for PUSCH transmission, including this in the DCI. The terminal can perform PUSCH transmission by applying a precoder indicated by the indicated TPMI and rank based on the transmission beam of the corresponding SRS resource, using the SRS resource indicated by the SRI.

[0170] Next, we describe non-codebook-based PUSCH transmission. Non-codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1, or can operate semi-statically via a configured grant. If at least one SRS resource is configured within an SRS resource set in which the usage value in the upper layer signaling SRS-ResourceSet is set to 'nonCodebook', the UE can be scheduled for non-codebook-based PUSCH transmission via DCI format 0_1.

[0171] For an SRS resource set in which the usage value in the upper layer signaling SRS-ResourceSet is set to 'nonCodebook', the UE can be configured with an NZP (non-zero power) CSI-RS resource associated with one SRS resource set. The UE can perform calculations for a precoder for SRS transmission through measurements on the NZP CSI-RS resource associated with the SRS resource set. If the difference between the last received symbol of the aperiodic NZP CSI-RS resource associated with the SRS resource set and the first symbol of the aperiodic SRS transmission at the UE is less than a specific symbol (e.g., 42 symbols), the UE may not expect that information for the precoder for SRS transmission is updated.

[0172] When the value of resourceType in SRS-ResourceSet, which is upper layer signaling, is set to 'aperiodic', the NZP CSI-RS associated with the SRS-ResourceSet may be indicated by the SRS request field in DCI format 0_1 ​​or 1_1. In one embodiment, when the NZP CSI-RS resource associated with the SRS-ResourceSet is an aperiodic NZP CSI resource, and the value of the field SRS request in DCI format 0_1 ​​or 1_1 is not '00', it may indicate that the NZP CSI-RS associated with the SRS-ResourceSet exists. The DCI may not indicate cross carrier or cross BWP scheduling. When the value of the SRS request indicates the existence of the NZP CSI-RS, the NZP CSI-RS may be located in a slot in which a PDCCH including the SRS request field is transmitted. The TCI states set on the scheduled subcarriers may not be set to QCL-TypeD.

[0173] If a periodic or semi-persistent SRS resource set is configured, the NZP CSI-RS associated with the SRS resource set can be indicated through the associatedCSI-RS within the upper layer signaling SRS-ResourceSet. For non-codebook based transmission, the terminal may not expect that the upper layer signaling spatialRelationInfo for the SRS resource and the associatedCSI-RS within the upper layer signaling SRS-ResourceSet are configured together.

[0174] When multiple SRS resources are configured, the UE can determine the precoder and transmission rank to be applied to PUSCH transmission based on the SRI indicated by the base station. In one embodiment, the SRI can be indicated through the SRS resource indicator field in the DCI or can be set through the srs-ResourceIndicator, which is a higher layer signaling. Similar to the codebook-based PUSCH transmission described above, when the UE is provided with an SRI through the DCI, the SRS resource indicated by the SRI can refer to an SRS resource corresponding to the SRI among the SRS resources transmitted before the PDCCH including the SRI. The UE can use one or more SRS resources for SRS transmission, and the maximum number of SRS resources that can be simultaneously transmitted in the same symbol within one SRS resource set and the maximum number of SRS resources can be determined by the UE capability reported by the UE to the base station. SRS resources transmitted simultaneously by the UE can occupy the same RB. The UE can configure one SRS port for each SRS resource. Only one SRS resource set with the usage value set to 'nonCodebook' in the upper layer signaling SRS-ResourceSet can be set, and up to four SRS resources for non-codebook-based PUSCH transmission can be set.

[0175] The base station transmits one NZP CSI-RS associated with an SRS resource set to the terminal, and the terminal can calculate a precoder to be used when transmitting one or more SRS resources within the SRS resource set based on the result measured upon reception of the NZP CSI-RS. When the terminal transmits one or more SRS resources within the SRS resource set in which usage is set to 'nonCodebook' to the base station, the terminal applies the calculated precoder, and the base station can select one or more SRS resources from among the received one or more SRS resources. In non-codebook based PUSCH transmission, the SRI can indicate an index that can express a combination of one or more SRS resources, and the SRI can be included in the DCI. The number of SRS resources indicated by the SRI transmitted by the base station can be the number of transmission layers of the PUSCH, and the terminal can transmit the PUSCH by applying the precoder applied to the SRS resource transmission for each layer.

[0176] The following describes a method for transmitting a single TB over multiple slots and for transmitting an uplink data channel (PUSCH) repeatedly in a 5G system. A 5G system can support two types of repeated transmission methods for an uplink data channel (e.g., PUSCH repetition transmission type A and PUSCH repetition transmission type B) and TB processing over multi-slot PUSCH (TBoMS), which transmits multiple PUSCHs over multiple slots in a single TB. Furthermore, a UE can be configured with either PUSCH repetition transmission type A or B through upper layer signaling. Furthermore, the UE can transmit TBoMS by receiving 'numberOfSlotsTBoMS' through a resource allocation table.

[0177] PUSCH repetitive transmission type A

[0178] - As described above, the start symbol and length of the uplink data channel are determined by the time domain resource allocation method within a single slot, and the base station can transmit the number of repeated transmissions to the terminal through higher layer signaling (e.g., RRC signaling) or L1 signaling (e.g., DCI). The number of slots N, set to numberOfSlotsTBoMS to determine TBS, is 1.

[0179] - The terminal may repeatedly transmit an uplink data channel having the same start symbol and length as the uplink data channel set above in consecutive slots based on the number of repeated transmissions received from the base station. In one embodiment, if at least one symbol among the symbols in the slot set by the base station as downlink to the terminal or the slot for repeated uplink data channel transmission set by the terminal is set as downlink, the terminal may omit uplink data channel transmission in the slot. For example, the terminal may not transmit an uplink data channel within the number of repeated uplink data channel transmissions. On the other hand, a terminal supporting Rel-17 repeated uplink data transmission determines a slot in which repeated uplink data transmission is possible as an available slot, and can count the number of transmissions when repeating an uplink data channel in a slot determined to be an available slot. If repeated uplink data channel transmission determined to be an available slot is omitted, repeated transmission can be performed through a slot that is available for transmission after postponing. Using Table 12 below, a redundancy version can be applied according to the redundancy version pattern set for each nth PUSCH transmission occasion.

[0180] PUSCH repetitive transmission type B

[0181] - As described above, the start symbol and length of the uplink data channel are determined by the time domain resource allocation method within one slot, and the base station can transmit the number of repetitions, numberofrepetitions, to the terminal through higher layer signaling (e.g., RRC signaling) or L1 signaling (e.g., DCI). In one embodiment, the number of slots N set to numberOfSlotsTBoMS to determine TBS is 1.

[0182] - First, based on the start symbol and length of the uplink data channel set above, the nominal repetition of the uplink data channel can be determined as follows. Here, the nominal repetition can mean the resource of the symbol set by the base station for repeated PUSCH transmission, and the terminal can determine the resource that can be used for uplink from the set nominal repetition. In this case, the slot where the nth nominal repetition starts is The symbol given by and the nominal repetition starts from the starting slot is can be given by . The slot where the nth nominal repetition ends is The symbol given by and whose nominal repetition ends in the last slot is can be given by . Here, n = 0, 1, ... numberofrepetitions-1, S represents the start symbol of the established uplink data channel, and L represents the symbol length of the established uplink data channel. K s indicates the slot in which the PUSCH transmission starts. can represent the number of symbols per slot.

[0183] - The terminal can determine an invalid symbol for PUSCH repetition transmission type B. A symbol configured for downlink by tdd-UL-DL-ConfigurationCommon or tdd-UL-DL-ConfigurationDedicated can be determined as an invalid symbol for PUSCH repetition transmission type B. Additionally, an invalid symbol can be set based on a higher layer parameter (e.g., InvalidSymbolPattern). For example, the higher layer parameter (e.g., InvalidSymbolPattern) can set an invalid symbol by providing a symbol-level bitmap spanning one or two slots. In one embodiment, a 1 in the bitmap can indicate an invalid symbol. Additionally, the period and pattern of the bitmap can be set via a higher layer parameter (e.g., periodicityAndPattern). If a higher layer parameter (e.g., InvalidSymbolPattern) is set and the InvalidSymbolPatternIndicator-ForDCIFormat0_1 or InvalidSymbolPatternIndicator-ForDCIFormat0_2 parameter indicates 1, the terminal may apply the invalid symbol pattern, and if it indicates 0, the terminal may not apply the invalid symbol pattern. Alternatively, if a higher layer parameter (e.g., InvalidSymbolPattern) is set and the InvalidSymbolPatternIndicator-ForDCIFormat0_1 or InvalidSymbolPatternIndicator-ForDCIFormat0_2 parameter is not set, the terminal may apply the invalid symbol pattern.

[0184] - After an invalid symbol is determined in each nominal repetition, the terminal can consider symbols excluding the determined invalid symbol as valid symbols. If at least one valid symbol is included in each nominal repetition, the nominal repetition may include one or more actual repetitions. Here, each actual repetition may refer to a symbol actually used for PUSCH repetitive transmission among the symbols set to the configured nominal repetition, and may include a continuous set of valid symbols that can be used for PUSCH repetitive transmission type B within one slot. The terminal may omit actual repetition transmission if an actual repetition with one symbol is set to valid, except when the symbol length L=1 of the configured uplink data channel. Using [Table 8] below, a redundancy version may be applied according to the configured redundancy version pattern for each n-th actual repetition.

[0185] TB processing over multiple slots (TBoMS)

[0186] - As described above, the start symbol and length of the uplink data channel are determined by the time domain resource allocation method within one slot, and the base station can transmit the number of repeated transmissions to the terminal through higher layer signaling (e.g., RRC signaling) or L1 signaling (e.g., DCI). In one embodiment, TBS can be determined using a value of N greater than or equal to the number of slots set to numberOfSlotsTBoMS.

[0187] - The terminal may transmit an uplink data channel having the same start symbol and length as the uplink data channel set above in consecutive slots based on the number of slots and the number of repeated transmissions for determining the TBS received from the base station. In one embodiment, if at least one symbol among the symbols in the slots set by the base station as downlink to the terminal or the slots for repeated transmission of the uplink data channel set by the terminal is set as downlink, the terminal may omit uplink data channel transmission in the corresponding slot. For example, it may be included in the number of repeated transmissions of the uplink data channel but may not be transmitted.

[0188] On the other hand, a terminal supporting Rel-17 uplink data repetition transmission determines a slot in which uplink data repetition transmission is possible as an available slot, and can count the number of transmissions in the slot determined as an available slot when repeating uplink data channels. If the repeat transmission of the uplink data channel determined as an available slot is omitted, repeat transmission can be performed through a slot that is available after postponement. In one embodiment, using Table 12 below, a redundancy version can be applied according to a redundancy version pattern set for each nth PUSCH transmission occasion.

[0189] rv id indicated by the DCI scheduling the PUSCHrv id to be applied to n th transmission occasion (repetition Type A) or TB processing over multiple slots) or n thactual repetition (repetition Type B)((n-(n mod N)) / N) mod 4 = 0((n-(n mod N)) / N) mod 4 = 0((n-(n mod N)) / N) mod 4 = 0((n-(n mod N)) / N) mod 4 = 000231223103310211023

[0190] Below, we describe a method for determining uplink available slots for single or multiple PUSCH transmissions in a 5G system.

[0191] According to one embodiment of the present disclosure, when the terminal sets AvailableSlotCounting to enable, the terminal can determine an available slot based on the tdd-UL-DL-ConfigurationCommon, tdd-UL-DL-ConfigurationDedicated, ssb-PositionsInBurst, and TDRA (time domain resource allocation) information field values ​​for Type A PUSCH repeated transmission and TBoMS PUSCH transmission. That is, if at least one symbol set as TDRA for PUSCH in a slot for PUSCH transmission overlaps with at least one symbol for a purpose other than uplink transmission, the slot can be determined as an unavailable slot.

[0192] Below, we describe a method for reducing SSB density through dynamic signaling to save base station energy in 5G systems.

[0193] FIG. 10 is a diagram illustrating an example of a method for resetting SSB transmission through dynamic signaling in a wireless communication system according to one embodiment of the present disclosure.

[0194] Referring to Fig. 10, the terminal can receive ssb-PositionsInBurst = '11110000' (1002) from the base station through upper layer signaling (SIB1 or ServingCellConfigCommon). At the subcarrier spacing of 30 kHz, a maximum of two synchronization signal blocks can be transmitted within 0.5 ms (or 1 slot length when 1 slot consists of 14 OFDM symbols), and accordingly, the terminal can receive 4 synchronization signal blocks (SSBs) within 1 ms (or 2 slot lengths when 1 slot consists of 14 OFDM symbols). At this time, the base station can reset the SSB transmission configuration information by broadcasting the bitmap '1010xxxx' (1004) through the Group / Cell common DCI (1003) having the nwes-RNTI (network energy saving-Radio Network Temporary Identifier, or es-RNTI) to reduce the density of SSB transmission for energy saving. At this time, the transmission of SS block#1 (1005) and SSblock#3 (1006) can be canceled based on the bitmap (1004) set by the Group / Cell common DCI. Fig. 10 illustrates a method (1001) for resetting SSB transmission through bitmap-based group / Cell common DCI.

[0195] In addition, the base station can reset the ssb-periodicity set through upper layer signaling via Group / Cell common DCI. In addition, timer information for indicating the application time of Group / Cell common DCI can be additionally set, and SSB can be transmitted based on the SSB transmission information reset by Group / Cell common DCI during the set timer. Afterwards, when the timer expires, the base station can operate with the SSB transmission information set by the existing upper layer signaling. This can be set to change from normal mode to energy saving mode through the timer, and thus reset the SSB configuration information. Alternatively, the base station can set the application time and period of the SSB configuration information reset through Group / Cell common DCI to the terminal using offset and interval information. In this case, the terminal may not monitor SSB during the set interval from the moment when the Group / Cell common DCI is received to the moment when the offset is applied.

[0196] Below, we describe a BWP or BW adaptation method through dynamic signaling for base station energy saving in 5G systems.

[0197] FIG. 11 is a diagram illustrating an example of a method for resetting BWP and BW through dynamic signaling in a wireless communication system according to one embodiment of the present disclosure.

[0198] Referring to Figure 11, the terminal can operate in BWP or BW activated through upper layer signaling and L1 signaling from the base station (1101). For example, the terminal can operate in a fixed power PSD. B It can operate through a full BW of 100MHz. At this time, the base station uses the same power PSD for energy saving. BThe BW and BWP can be adjusted to activate a narrower BW of 40 MHz for the terminal (1102). At this time, the BW or BWP adjustment operation for energy saving of the base station can be set to match the BWP and BW settings that are set UE-specifically through group common DCI and cell specific DCI (1103). For example, UE#0 and UE#1 can have different BWP configurations and locations. At this time, the BW and BWP of all terminals can be set to be the same in order to save energy by reducing the BW used by the base station. At this time, the BWP or BW in the operation for energy saving can be set to one or more, and this can be used to set the BWP for each UE group.

[0199] In describing 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.

[0200] - MIB (master information block)

[0201] - SIB (system information block) or SIB

[0202] - RRC (radio resource control)

[0203] - MAC (medium access control) CE (control element)

[0204] In addition, L1 signaling may be signaling corresponding to at least one or a combination of one or more signaling methods using the following physical layer channels or signaling.

[0205] - PDCCH (physical downlink control channel)

[0206] - DCI (Downlink Control Information)

[0207] - UE-specific DCI

[0208] - Group common DCI

[0209] - Common DCI

[0210] - Scheduling DCI (e.g. DCI used for scheduling downlink or uplink data)

[0211] - Non-scheduled DCI (e.g. DCI not intended for scheduling downlink or uplink data)

[0212] - PUCCH (physical uplink control channel)

[0213] - UCI (uplink control information)

[0214] In the present disclosure below, the above examples are described through multiple embodiments, but they are not independent, and one or more embodiments may be applied simultaneously or in combination.

[0215] Below, a DRX alignment method through dynamic signaling for base station energy saving in a 5G system is described.

[0216] FIG. 12 is a diagram illustrating an example of a method for resetting DRX through dynamic signaling in a wireless communication system according to one embodiment of the present disclosure.

[0217] Referring to FIG. 12, the base station can configure DRX for each terminal specifically through upper layer signaling. For example, each terminal can be configured with different drx-LongCycle (1202) or drx-ShortCycle, drx-onDurationTimer (1203), and drx-InactivityTimer (1204). Thereafter, the base station can configure UE-specific DRX settings for energy saving in a UE group-specific or cell-specific manner through L1 signaling (1201). Through this, the base station can achieve the same effect of saving power as the terminal through DRX for energy saving.

[0218] Below is an example illustrating the discontinuous transmission (DTx) operation for reducing energy consumption of a base station in a 5G system.

[0219] FIG. 13 is a diagram illustrating an example of a DTx method for base station energy saving according to one embodiment of the present disclosure.

[0220] Referring to FIG. 13, the base station can configure DTx for energy saving through upper layer signaling (e.g., new SIB for DTx or RRC signaling) and L1 signaling (e.g., DCI). At this time, the base station can set dtx-onDurationTimer (1305) for transmitting a PDCCH for scheduling DL SCH (downlink shared channel) for DTx operation or a reference signal for measuring RRM measurement, beam management, and path loss, dtx-InactivityTimer (1306) for receiving a PDSCH after receiving a PDCCH for scheduling DL SCH, dtx-offset (1304) for setting information for synchronizing a synchronization signal (1303) before dtx-onDurationTimer and an offset between dtx-onDurationTimer after the synchronization signal, and dtx-(Long)Cycle (1302) for DTx to operate periodically based on the setting information. At this time, dtx-cycle can be set to multiple long cycles and short cycles.

[0221] During the operation of DTx, the base station considers the transmitter to be off (or inactive), and therefore may not transmit the DL downlink control channel (DL CCH), DL SCH, and DL RS. That is, the base station can only transmit synchronization signals during the DTx operation, and can also transmit downlink channels and signals (e.g., PDCCH, PDSCH, reference signals, etc.) only during the dtx-onDurationTimer and dtx-InactivityTimer. At this time, SS-gapbetweenBurst (gap between SS bursts in the time domain) or the number of SS bursts can be additionally set as additional information of the configured SS.

[0222] Below, a method for activating a base station through a gNB wake-up signal (WUS) during the base station's inactive mode to reduce energy consumption of the base station in a 5G system is described.

[0223] FIG. 14 is a diagram illustrating an example of the operation of a base station according to gNB WUS according to one embodiment of the present disclosure.

[0224] Referring to FIG. 14, the base station can keep the transmitter end in the Off (or inactive) state while the base station is in an inactive state (or sleep mode) to save energy. Thereafter, the base station can receive a gNB WUS (1402) from the terminal to activate the sleep mode of the base station. Thereafter, when the base station receives the WUS from the terminal through the Rx terminal, the base station can change the Tx terminal to the On (or active) state (1403). Thereafter, the base station can perform downlink transmission to the terminal. At this time, the base station can perform synchronization after the Tx is on and transmit control information and data. In addition, various uplink signals, such as PRACH, scheduling request (SR PUCCH), PUCCH including ACK, etc., can be considered as gNB WUS. Through the above method, the base station can perform energy saving, and at the same time, the terminal can improve latency.

[0225] At this time, the base station can set a WUS occasion for receiving the gNB WUS and a synchronization reference signal for synchronization before the terminal transmits the gNB WUS. At this time, SSB, TRS (tracking reference signal), Light SSB (PSS and SSS), consecutive SSBs, or new RS (continuous PSS + SSS) can be considered as the synchronization reference signal, and PRACH, PUCCH with SR, or a sequence-based signal can be considered as the WUS. The synchronization reference signal (1404) for the terminal to activate the deactivation mode for energy saving of the base station and the WUS occasion for receiving the WUS can be repeatedly transmitted with a WUS-RS cycle (1405). In the case of FIG. 14, one embodiment is described by taking 1-to-1 mapping of Sync RS and WUS occasion as an example, but the present disclosure is not limited thereto. For example, the synchronization reference signal and the WUS occasion can be N-to-1 mapped, 1-to-N mapped, or N-to-M mapped.

[0226] Below, a method for dynamically turning on / off spatial domain elements (i.e., antenna, PA (power amplifier), or TxRUs (transceiver units or transmission radio units)) of a base station to save base station energy in a 5G system is described.

[0227] FIG. 15 is a diagram illustrating an example of an antenna adaptation method of a base station for energy saving in a wireless communication system according to one embodiment of the present disclosure.

[0228] Referring to FIG. 15, the base station can adjust the Tx antenna port per RU (radio unit) for network energy savings (NWES) (1501). For example, since the PA of the base station accounts for most of the energy consumption of the base station, the base station can turn off the Tx antenna to save energy. At this time, the base station can refer to / use the RSRP (reference signal received power), CQI (channel quality indicator), and RSRQ (reference signal received quality) of the UE to determine whether the Tx antenna can be turned off. The base station can perform Tx transmission by adjusting the number of activated Tx antennas per UE group or per UE. At this time, the base station can set information including one or more of beam information or reference signal information (e.g., one or more of CSI resource, CSI resource set, or CSI report) according to antenna on / off to the UE through higher layer signaling (e.g., RRC signaling) or DCI signaling. Additionally, the base station can configure different antenna information for each BWP and reset the antenna information according to BWP changes. Furthermore, the base station can receive CSI feedback from the terminal to determine whether spatial domain (SD) adaptation is possible. The base station can decide on SD adaptation (based on the CSI feedback). The base station can receive multiple feedback from the terminal through antenna structure hypotheses of multiple antenna patterns for SD adaptation.

[0229] More specifically, the base station may apply multiple types (e.g., two types) of SD adaptation for energy saving (1502). For example, the multiple types may include Type 1 SD adaptation (1503) and Type 2 SD adaptation (1504).

[0230] When Type 1 SD Adaptation (1503) is applied, the base station can adapt the number of antenna ports while maintaining the number of physical antenna elements per antenna port (i.e., logical port). At this time, the RF characteristics (e.g., transmit power and / or beam) per port can be the same. Therefore, the terminal can measure the CSI-RS of the same port by combining them during CSI measurement (e.g., L1-RSRP (layer 1-RSRP), L3-RSRP (layer 3-RSRP), etc.).

[0231] Alternatively, when Type 2 SD adaptation (1504) is applied, the base station can have the same number of antenna ports (i.e., logical ports) and turn on / off physical antenna elements per port (1504). At this time, the RF characteristics of each port may vary. During CSI measurement, the terminal can distinguish the CSI-RS of the same port and perform measurements separately. The base station can save energy through one or more of multiple types of SD adaptation methods, including the two types of SD adaptation methods described above.

[0232] Below, we describe a method for configuring on-demand SSB and SIB1 for applying on-demand SSB and SIB for energy saving of base stations in a 5G system. In the present disclosure, on-demand operation may mean including on-demand SSB and on-demand SIB (on-demand SIB1). Furthermore, while the following description focuses on on-demand SSB as an example, it is of course applicable to on-demand SIB (on-demand SIB1).

[0233] FIG. 16 is a diagram illustrating an example of On-demand SSB operation of a base station and a terminal according to one embodiment of the present disclosure.

[0234] Referring to FIG. 16, the base station can apply on-demand SSB operation to one or multiple SCells during CA operation. More specifically, the base station can periodically perform SSB transmission on the PCell (1601). The base station can transmit on-demand SSB configuration for SCells to the UE through upper layer signaling and / or L1 signaling. For example, the base station can configure on-demand SSB configuration on the PCell to the UE through RRC signaling (1602). Thereafter, the UE can trigger SSB transmission of the SCell (e.g., SCell#1, 1604) by transmitting an uplink signal (e.g., PUCCH or PRACH) (1606) as a WUS based on the configured information. The base station can transmit an SSB burst (1605) after receiving the WUS.

[0235] For the above operation, the on-demand SSB configuration and SCell configuration method can be set by one or a combination of the following methods, and SCell activation / deactivation can also be determined.

[0236] FIG. 17 is a diagram illustrating an example of a method for activating / deactivating SCell and setting On-demand SSB of a base station according to one embodiment of the present disclosure.

[0237] Referring to FIG. 17, the base station can configure a secondary cell group including candidate SCells (e.g., CellgroupConfig) via higher layer signaling (e.g., RRC signaling) (1703). Thereafter, the base station can instruct each terminal which SCell to activate, thereby activating and deactivating the SCell (1704). More specifically, the base station can activate or deactivate one or more SCells by setting the sCellState of the RRC signaling SCellConfig to enable or via MAC CE signaling. Thereafter, the base station can configure on-demand operation for the activated SCell via at least one of RRC signaling, MAC CE signaling, and L1 signaling (1705). At this time, the configuration of the on-demand operation can be configured during the process of activating the SCell in Stage-1 (1701) or applied together with the SCell activation. Alternatively, the configuration of On-demand operation can be applied only in Stage-2 (1702), where On-demand operation can be configured via sCell-config for the activated SCell or via MAC CE or L1 signaling (e.g., group common DCI). Furthermore, On-demand operation can be enabled or disabled simultaneously with SCell activation.

[0238] Through the above methods, the base station can configure and instruct the terminal to activate / deactivate SCells and perform on-demand operations. Thereafter, the terminal can determine whether to receive SSB and transmit WUS based on whether on-demand operations are activated on the SCell based on the configuration information.

[0239] The following proposes methods for SCell activation / deactivation and on-demand configuration of the present disclosure. A base station can configure on-demand operations, including SCell activation / deactivation, for a terminal based on one or a combination of the following methods.

[0240] [Setting 1]

[0241] In a configuration 1 according to one embodiment, the base station can set configuration information for on-demand operation in SCell and whether to activate on-demand operation through RRC signaling for energy saving.

[0242] The base station can set whether to activate / deactivate SCell and whether to activate / deactivate On-demand SSB or SIB1 operation to the terminal through RRC signaling.

[0243] For example, in sCellConfig as in Table 13, whether to enable on demand operation can be set by RRC signaling.

[0244] sCellConfig ::= SEQUENCE {sCellIndex SCellIndex,sCellConfigCommon ServingCellConfigCommon OPTIONAL, -- Cond SCellAddsCellConfigDedicated ServingCellConfig OPTIONAL, -- Cond SCellAddMod...,[[smtc SSB-MTC OPTIONAL -- Need S]],[[sCellState-r16 ENUMERATED {activated} OPTIONAL, -- Cond SCellAddSynconDemandSSB-r18 ENUMERATED {activated} OPTIONALonDemandSIB-r18 ENUMERATED {activated} OPTIONALonDemand-r18 ENUMERATED {Disable, SSB, SIB, Both} OPTIONALsecondaryDRX-GroupConfig-r16 ENUMERATED {true} OPTIONAL -- Need S]],[[preConfGapStatus-r17 BIT STRING (SIZE (maxNrofGapId-r17)) OPTIONAL, -- Cond PreConfigMGgoodServingCellEvaluationBFD-r17 GoodServingCellEvaluation-r17 OPTIONAL, -- Need RsCellSIB20-r17 SetupRelease { SCellSIB20-r17} OPTIONAL -- Need M]],[[plmn-IdentityInfoList-r17 SetupRelease {PLMN-IdentityInfoList} OPTIONAL, -- Cond SCellSIB20-Optnpn-IdentityInfoList-r17 SetupRelease {NPN-IdentityInfoList-r16} OPTIONAL -- Cond SCellSIB20-Opt]]}

[0245] Referring to Table 13, the base station can indicate whether to perform on-demand operation in the SCell corresponding to sCellIndex by configuring the on-demand operation for energy saving of the base station through the sCellConfig RRC configuration, such as onDemandSSB-r18, onDemandSIB-r18, or onDemand-r18, through RRC signaling. The above example corresponds to an embodiment of the present disclosure, and may be configured by being included in sCellConfigCommon or sCellConfigDedicated in addition to the sCellConfig IE.

[0246] In addition, the configuration information (e.g., period, pattern, number of SSBs) used when the base station or terminal starts transmission by activating the on-demand SSB or SIB can be configured as an individual RRC signal. Additionally, in the case of SSB, a list of specific patterns can be configured through RRC signaling, and the SSB pattern can be configured for each SCell by indicating / configuring the pattern index of the list through MAC-CE or DCI. The multi-pattern configuration method can also be applied to the on-demand operation of other channels such as SIB1. In this case, the on-demand operation configuration can operate together with or independently of the SCell activation / deactivation information. For example, the on-demand operation configuration can be applied to an SCell whose sCellState is set to activated. On the other hand, the on-demand operation is configured individually regardless of whether the SCell is activated, and the SCell activation operation can be performed together when the base station activates the SCell or the terminal activates the on-demand operation of a deactivated SCell through WUS transmission. Additionally, WUS transmission-related configuration information and WUS pattern information for requesting on-demand operation of the terminal can be set to the terminal through RRC signaling.

[0247] [Setting 2]

[0248] In a configuration 2 according to one embodiment, the base station can configure on-demand operation on the SCell and / or activation of one or more SCells via MAC CE signaling for energy saving. In addition, the base station can instruct the terminal on a pattern for on-demand operation on the SCell.

[0249] The base station can individually or together set whether to enable / disable SCell and whether to enable / disable On-demand SSB or SIB1 operation to the terminal through MAC CE.

[0250] FIG. 18 is a diagram illustrating an example of a method for activating / deactivating a MAC CE-based SCell and setting an On-demand SSB of a base station according to one embodiment of the present disclosure.

[0251] Referring to FIG. 18, the base station can indicate on-demand SSB operation activation / deactivation and / or on-demand SSB pattern for one or multiple SCells via MAC CE signaling. For example, the base station can indicate on-demand SSB operation activation / deactivation for SCells C1 to C7 via MAC CE having 1 octet (1801). Ci can correspond to the index of a candidate SCell configured by RRC. For example, the SCell index can correspond to the order of lowest to highest index in ascending order of i. In this case, on-demand SSB operation activation and SCell activation / deactivation can be indicated together via the MAC CE. In other words, the terminal can determine that the SCell with on-demand SSB operation activated is the activated SCell.

[0252] The on-demand SSB pattern can be predefined between the terminal and the base station, or can be configured to the terminal through separate information. As another example, the base station can instruct the activation of on-demand SSB operation for SCells C1 to C7 through a MAC CE having multiple octets and instruct the on-demand SSB pattern for each SCell (1802). The base station can instruct the on-demand SSB pattern by selecting a pattern index from a pattern list configured through RRC signaling. In this case, the activation of on-demand SSB operation and whether to activate / deactivate the SCell can be instructed together through the MAC CE.

[0253] [Setting 3]

[0254] In one embodiment, in configuration 3, the base station can configure on-demand operation on the SCell and / or activation of one or more SCells via DCI for energy saving. Furthermore, the base station can indicate on-demand transmission patterns for on-demand operation on the SCell.

[0255] The base station can individually or jointly configure SCell activation / deactivation and On-demand SSB or SIB1 operation activation / deactivation for the terminal via DCI. In this case, DCI can be applied as cell-specific DCI, group-common DCI, or terminal-specific DCI.

[0256] For example, a group common DCI format such as Table 14 can be set considering one or multiple SCells.

[0257] DCI format 2_X is used for notifying on-demand SSB on one or more the activated SCell by RRC and MAC CE.The following information is transmitted by means of the DCI format 2_X with CRC scrambled by Ondemad-RNTI:- block number 1, block number 2,쪋, block number Nwhere the starting position of a block is determined in order of SCellIndexThe following fields defined for the block:- On-demand SSB indication - 1 bit- On-demand pattern indication - N bit if higher layer parameter onDemandpatternList is configured- WUS occasion indication - N bit if higher layer parameter WUSResourceAllocationList is configuredThe size of DCI format 2_X is determined by the number of activated SCell.

[0258] Referring to Table 14, the DCI is composed of multiple blocks for each SCell, and the number of blocks can be determined by the number of activated SCells or the number of candidate SCells belonging to the secondary cell group. Furthermore, the UE can determine the block location (i.e., the starting position of the corresponding bit) for each SCell based on information configured through higher-layer signaling (e.g., RRC signaling) or based on the SCell index. For example, if {1,2,3,7} is set as the SCell index, allocation to blocks 1 through 4 starting from the lowest SCell index can be considered.

[0259] At this time, each block may include a bit indicating whether on-demand operation in the corresponding SCell is activated. For example, considering on-demand SSB and SIB, two bits may indicate '00' as deactivated, '01' as on-demand SSB activation, '10' as on-demand SIB1 activation, and '11' as on-demand SSB & SIB1 activation. In addition, each block may include bits indicating WUS configuration information and on-demand pattern information after the bit indicating the activation information. The above DCI format configuration may be used in combination with RRC signaling and MAC CE signaling. In addition, the configuration of the block is one embodiment and does not limit the scope of the present disclosure.

[0260] Through the embodiments of the present disclosure, the base station can configure and activate on-demand operations for the terminal, and also indicate whether to activate / deactivate the SCell. Furthermore, the values ​​of the above signaling signals can be configured in various ways, for example.

[0261] Through the above-described methods or embodiments, the energy consumption of the base station can be reduced. Furthermore, the above-described methods or embodiments can be simultaneously configured through one or more combinations.

[0262] The methods according to one embodiment of the present disclosure can reduce energy consumption at a base station. Furthermore, the methods according to one embodiment of the present disclosure can be configured / used singly or simultaneously in combination with one or more other methods.

[0263] According to one embodiment of the present disclosure, a base station proposes a method for transmitting signals and channels that are always transmitted periodically only as needed to reduce energy consumption. More specifically, the base station can transmit signals such as SSB or SIB1 that are always transmitted periodically according to an uplink signal of a terminal and a decision of the base station. At this time, the base station can configure configuration information for the above operation to the terminal through upper layer signaling and / or L1 signaling. In addition, operations of the terminal according to the above configuration can be defined. In the present disclosure, the terms "energy saving," "reducing energy consumption," and "reducing energy consumption" may be used interchangeably and understood to have the same meaning. Unless specifically stated otherwise, the present disclosure may include operations of SIBs other than SSB and SIB1.

[0264] According to one embodiment of the present disclosure, we propose the operation of a terminal during on-demand operation in a SCell for base station energy saving. More specifically, a base station can configure SCell group configuration information for CA operation, SCell activation / deactivation configuration information, and on-demand operation configuration information to a terminal via upper layer signaling and / or L1 signaling. The operation of a terminal that receives the configuration information can be defined. Through this, the terminal can also save energy without performing unnecessary operations during the energy saving operation of the base station.

[0265] FIG. 19 is a diagram illustrating an example of operation of a terminal according to CA settings of a base station according to one embodiment of the present disclosure.

[0266] Referring to FIG. 19, the base station can configure secondary cell group configuration information of candidate SCells to the terminal via RRC signaling for CA operation (1901). The base station can activate and deactivate up to four SCells among the configured candidate SCells via RRC signaling and / or MAC CE signaling (1902). At this time, the terminal can measure and report RSRP, RSRQ, and SINR of the SCell based on measurement and reporting configuration information configured by higher layer signaling (e.g., VarMeasConfig) from the base station to determine candidate SCells that can be included in the secondary cell group (1903). The base station can determine the secondary cell group based on the measurement information received from the terminal. For example, the base station can release a concerned SCell with poor performance, such as RSRP, RSRQ, and SINR, from the secondary cell group via higher layer signaling. Meanwhile, the base station can add SCells with good RSRP, RSRQ, and SINR to the secondary cell group through upper-layer signaling. The base station can then activate / deactivate up to four SCells within the secondary cell group. The UE can perform the following actions on the activated SCell after a configured processing time from the time of receiving the configuration information for SCell activation / deactivation (1904).

[0267] - SRS transmission on the SCell,

[0268] - CSI reporting for SCell,

[0269] - PDCCH monitoring on the SCell,

[0270] - PDCCH monitoring for the SCell,

[0271] - PUCCH transmissions on the SCell, if configured.

[0272] Through the above method, the base station can configure CA operation and activate and deactivate SCell. The base station can add on-demand operation to the CA operation to save energy at the base station. At this time, depending on the base station's CA and on-demand configuration method, the terminal's operation (e.g., operation 1 or operation 2) can be defined as one or a combination of the following operations.

[0273] [Movement 1]

[0274] In operation 1 according to one embodiment, the base station provides the operation of the terminal when applying an on-demand operation for energy saving to the SCell during CA operation.

[0275] FIG. 20 is a diagram illustrating an example of operation of a terminal according to CA settings and on-demand settings of a base station according to one embodiment of the present disclosure.

[0276] Referring to FIG. 20, a base station can configure secondary cell group configuration information composed of candidate SCells for CA operation to a terminal via RRC signaling (2001). The base station can activate SCell (de)activation and on-demand SSB operation on up to four of the candidate SCells in the secondary cell group (2002). For example, the base station can receive uplink signals (e.g., WUS, PUCCH, PUSCH, PRACH, etc.) from the terminal and activate SCell activation and on-demand operation based on the uplink signals. Accordingly, when the terminal receives the secondary cell group configuration via higher layer signaling and has the base station's configuration and the terminal's capability for on-demand operation on the SCell, the terminal can perform the following operations during section (A) (2003) of FIG. 20:

[0277] - Measurement and reporting for SCell addition and modification,

[0278] - WUS transmission for activating SCell and requesting on-demand (SSB / SIB1), if needed.

[0279] Through the terminal operation in section (A) above, the base station can determine a candidate SCell and a secondary cell group, and can determine whether to activate the SCell and perform on-demand SSB / SIB transmission through the WUS signal transmitted from the terminal (2003). The terminal can determine that the SCell is activated after receiving the SCell activation setting from the base station or after the WUS transmission. Afterwards, when the on-demand setting is activated in section (B) (2004), the terminal can perform the following operations depending on whether on-demand SSB transmission is performed on the corresponding SCell (2004):

[0280] - If on-demand SSB is configured and on-demand SSB transmission is activated,

[0281] - On-demand SSB based measurement and RSRP / RSRQ / SINR reporting, if configured

[0282] - SRS transmission on the SCell

[0283] - CSI reporting for SCell

[0284] - PDCCH monitoring on the SCell

[0285] - PDCCH monitoring for the SCell

[0286] - PUCCH transmissions on the SCells, if configured

[0287] - Else on-demand SSB is configured and on-demand SSB transmission is deactivated,

[0288] - WUS transmission for triggering on-demand SSB, if needed

[0289] - SRS transmission on the SCell

[0290] - CSI reporting for SCell

[0291] - PDCCH monitoring for the SCell

[0292] - PUCCH transmissions on the SCells, if configured

[0293] As described above, depending on whether on-demand SSB is being transmitted in a SCell for which on-demand SSB operation is configured (whether on-demand SSB transmission is activated), the operation of the terminal can be defined, and WUS transmission for requesting on-demand SSB transmission and on-demand SSB-based measurement and reporting operations can be provided. For example, in the case of the on-demand SSB-based measurement and reporting operation, an aperiodic reporting operation can be performed based on the fastest on-demand SSB transmission after an SCell activation signal and on-demand SSB operation configuration. After SCell activation, the quality of the corresponding SCell can be checked through a fast measurement report, and handover and other SCell attachment can be applied if necessary. The above operation is one embodiment and does not limit the scope of the present disclosure, and the operations of the terminal can be determined according to the configuration or a combination thereof as needed.

[0294] [Movement 2]

[0295] In operation 2 according to one embodiment, the base station provides an operation of a terminal when applying an on-demand operation for energy saving to an SCell during CA operation.

[0296] FIG. 21 is a diagram illustrating an example of operation of a terminal according to CA settings and on-demand settings of a base station according to one embodiment of the present disclosure.

[0297] Referring to FIG. 21, a base station can configure secondary cell group configuration information composed of candidate SCells for CA operation to a terminal via RRC signaling (2101). The base station can activate / deactivate up to four SCells among the candidate SCells of the secondary cell group (2102). The base station can configure whether to support on-demand SSB operation in the activated SCells (2103). In an activated SCell that supports on-demand SSB operation, the base station can receive an uplink signal (e.g., WUS, PUCCH, PUSCH, PRACH, etc.) from a terminal and initiate on-demand SSB or SIB1 transmission based on the uplink signal. At this time, different terminal operations can be defined for each section (A) to (C) between the configurations.

[0298] More specifically, after the terminal receives secondary cell group configuration information from the base station, in section (A), the terminal can perform measurement and reporting to determine the secondary cell group (2104). After the processing time including the A / N transmission for the signal for SCell activation from the time when the terminal receives the SCell activation / deactivation instruction from the base station through RRC signaling or MAC-CE signaling, the following terminal operations can be performed depending on whether on-demand operation is supported and whether on-demand SSB transmission is activated. More specifically, as in section (2106) of (C) of FIG. 21, on-demand SSB transmission may be activated in a serving cell that supports on-demand SSB operation, or on-demand SSB transmission may be deactivated in a serving cell that supports on-demand operation because there is no need for on-demand. The terminal operations in sections (B) (2105) and (C) (2106) can be determined as follows.

[0299] - If on-demand SSB is not configured on the serving cell,

[0300] - SRS transmission on the SCell

[0301] - CSI reporting for SCell

[0302] - PDCCH monitoring on the SCell

[0303] - PDCCH monitoring for the SCell

[0304] - PUCCH transmissions on the SCell, if configured.

[0305] - else on-demand SSB is configured on the serving cell, and on-demand SSB transmission is deactivated

[0306] - On-demand SSB based measurement and RSRP / RSRQ / SINR reporting, if configured

[0307] - WUS transmission for triggering on-demand SSB, if needed

[0308] - SRS transmission on the SCell

[0309] - CSI reporting for SCell

[0310] - PDCCH monitoring for the SCell

[0311] - PUCCH transmissions on the SCells, if configured

[0312] - else on-demand SSB is configured on the serving cell, and on-demand SSB transmission is activated

[0313] - On-demand SSB based measurement and RSRP / RSRQ / SINR reporting, if configured

[0314] - WUS transmission for triggering on-demand SSB, if needed (일례로, on-demand SSB 전송을 비활성화 하기 위해서 또는 on-demand 패턴을 요청하기 위하여 WUS가 전송될 수 있다)

[0315] - SRS transmission on the SCell

[0316] - CSI reporting for SCell

[0317] - PDCCH monitoring on the SCell

[0318] - PDCCH monitoring for the SCell

[0319] - PUCCH transmissions on the SCells, if configured

[0320] As described above, depending on whether on-demand SSB is transmitted in an SCell for which on-demand SSB operation is configured, the operation of the terminal can be defined, and WUS transmission for requesting on-demand SSB transmission and on-demand SSB-based measurement and reporting operations can be provided. In this case, in the case of the on-demand SSB-based measurement and reporting operation, an aperiodic reporting operation can be performed based on the fastest on-demand SSB transmission after an SCell activation signal and on-demand SSB operation configuration. After SCell activation, the quality of the corresponding SCell can be checked through a fast measurement report, and handover and attachment to another SCell can be applied if necessary. The above operation is one embodiment and does not limit the scope of the present disclosure, and the operations of the terminal can be determined according to the configuration or a combination thereof as needed.

[0321] The above two operations (e.g., operation 1 or operation 2) can define the operation of the terminal in the SCell to which on-demand SSB is applied. That is, the terminal can perform uplink transmission including WUS transmission and PDCCH reception in the PCell when SSB is not actually transmitted or when SSB is not transmitted but on-demand operation can be requested. On the other hand, if on-demand SSB transmission or on-demand operation is deactivated while the SCell is configured through upper layer signaling and L1 signaling, and periodic SSB transmission is performed, the terminal can perform the operation in section (B) of FIG. 19.

[0322] Additionally, the application time of the above actions can be determined by one or a combination thereof as follows.

[0323] [Point 1]

[0324] In point 1 according to one embodiment, a start point of operation of a terminal is provided when a base station applies an on-demand operation for energy saving to an SCell during a CA operation. Point 1 of the present disclosure may be applied to secondary cell group configuration, SCell activation / deactivation, and on-demand SSB transmission activation / deactivation, which instruct operations in sections (A), (B), and (C) of the above operations. More specifically, the base station may instruct and configure secondary cell group configuration, SCell activation / deactivation, and on-demand SSB transmission activation / deactivation through upper layer signaling and / or L1 signaling. In this case, the terminal may perform the operation of the corresponding section after applying a processing time after receiving the signaling. In this case, the processing time may be considered, including the Ack / Nack transmission time for the signaling of the base station. Additionally, different processing times may be applied to RRC signaling, MAC CE signaling, PDCCH signaling, and PDSCH signaling, which may be determined by upper layer signaling and UE capabilities.

[0325] [Point 2]

[0326] In point 2 according to one embodiment, a start point of operation of a terminal is provided when a base station applies an on-demand operation for energy saving to an SCell during a CA operation. Point 2 of the present disclosure represents a point in time when a terminal performs an operation considering that an on-demand SSB is requested through a WUS during the operations of sections (A), (B), and (C) above and that the on-demand SSB is subsequently transmitted from the base station. More specifically, the terminal may transmit a WUS to request an on-demand SSB and, after considering the processing time of the WUS, perform the operations defined in the above operations considering the on-demand SSB transmission. In this case, the processing time may be determined by the upper layer signaling of the base station and the UE capability.

[0327] Through the above methods, the base station can instruct SCells to perform on-demand operations for energy saving purposes via upper layer signaling and / or L1 signaling, and the terminal's operations can be defined according to the base station's settings. This can reduce energy consumption due to unnecessary terminal operations during the base station's energy saving operation, thereby achieving the terminal's energy saving effect.

[0328] FIG. 22 is a flowchart illustrating an example of the operation of a terminal performing an energy saving method in a wireless communication system according to one embodiment of the present disclosure. Based on FIG. 22, the operation of the terminal can be provided during on-demand operation of the base station in the SCell for energy saving.

[0329] Referring to FIG. 22, in step 2201, the terminal may receive secondary cell group configuration information including information on one or more SCells from the base station via higher layer signaling (e.g., RRC signaling). In step 2202, the terminal may perform measurements to determine the secondary cell group and transmit a report to the base station. In step 2203, the terminal may receive SCell (de)activation and on-demand operation configuration information of one or more secondary cell groups via higher layer signaling (e.g., RRC signaling) and L1 signaling. In step 2204, the terminal may perform WUS transmission or related PDCCH monitoring depending on whether on-demand configuration is performed on the activated SCell. In step 2205, the terminal may receive SCell (de)activation and on-demand SSB transmission configuration information via higher layer signaling (e.g., RRC signaling) and L1 signaling. At step 2206, the terminal can perform on-demand SSB reception and WUS transmission on the activated SCell.

[0330] The above flowchart illustrates exemplary methods that can be implemented according to the principles of the present disclosure, and various modifications may be made to the methods depicted in the flowcharts herein. For example, although depicted as a series of steps, various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other instances, steps may be omitted or replaced with other steps.

[0331] FIG. 23 is a flowchart illustrating an example of an operation of a base station performing an energy saving method of a wireless communication system according to one embodiment of the present disclosure.

[0332] Referring to FIG. 23, in step 2301, the base station may transmit secondary cell group configuration information including one or more SCells to the terminal via higher layer signaling (e.g., RRC) for energy saving of the base station. In step 2302, the base station may receive a measurement result for determining the secondary cell group from the terminal. In step 2303, the base station may transmit SCell (de)activation and on-demand operation configuration information of one or multiple secondary cell groups to the terminal via higher layer signaling (e.g., RRC) and L1 signaling. In step 2304, the base station may perform WUS reception or related PDCCH transmission depending on whether on-demand configuration is performed on the activated SCell. In step 2305, the base station may transmit SCell (de)activation and on-demand SSB transmission configuration information via higher layer signaling (e.g., RRC) and L1 signaling. At step 2306, the base station can perform on-demand SSB transmission and WUS reception on the activated SCell.

[0333] The above flowchart illustrates exemplary methods that can be implemented according to the principles of the present disclosure, and various modifications may be made to the methods depicted in the flowcharts herein. For example, although depicted as a series of steps, various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other instances, steps may be omitted or replaced with other steps.

[0334] FIG. 24 is a block diagram illustrating an example of a structure of a terminal according to one embodiment of the present disclosure.

[0335] Referring to FIG. 24, a terminal (2400) may include a transceiver (2401), a control unit (e.g., a processor) (2402), and a storage unit (e.g., a memory) (2403). The transceiver (2401), the control unit (2402), and the storage unit (2403) of the terminal (2400) may operate according to at least one or a combination of the methods corresponding to the above-described embodiments. However, the components of the terminal (2400) are not limited to the illustrated example. According to other embodiments, the terminal (2400) may include more or fewer components than the components described above. In addition, in certain cases, the transceiver (2401), the control unit (2402), and the storage unit (2403) may be implemented in the form of a single chip.

[0336] The transceiver (2401) may, according to one embodiment, be configured with a transmitter and a receiver. The transceiver (2401) may transmit and receive signals with a base station. The signals may include control information and data. The transceiver (2401) may be configured to include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-downconverts the received signal. The transceiver (2401) may receive a signal through a wireless channel and output the signal to the control unit (2402), and may transmit the signal output from the control unit (2402) through the wireless channel.

[0337] The control unit (2402) may control a series of procedures that the terminal (2400) may perform according to the embodiments of the present disclosure described above. For example, the control unit (2402) may perform or control the operation of the terminal to perform at least one or a combination of methods according to the embodiments of the present disclosure. The control unit (2402) may include at least one processor. For example, the control unit (2402) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls an upper layer (e.g., an application).

[0338] The storage unit (2403) can store control information or data, and can have an area for storing data required for controlling the control unit (2402) and data generated during control by the control unit (2402).

[0339] FIG. 25 is a block diagram illustrating an example of the structure of a base station according to one embodiment.

[0340] Referring to FIG. 25, a base station (2500) may include a transceiver (2501), a control unit (e.g., a processor) (2502), and a storage unit (e.g., a memory) (2503). The transceiver (2501), the control unit (2502), and the storage unit (2503) of the base station (2500) may operate according to at least one or a combination of methods corresponding to the above-described embodiments. However, the components of the base station (2500) are not limited to the illustrated example. According to other embodiments, the base station (2500) may include more or fewer components than the components described above. Furthermore, in certain cases, the transceiver (2501), the control unit (2502), and the storage unit (2503) may be implemented in the form of a single chip.

[0341] The transceiver (2501) may, according to one embodiment, be composed of a transmitter and a receiver. The transceiver (2501) may transmit and receive signals with a terminal. The signals may include control information and data. The transceiver (2501) may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-converts the received signal. The transceiver (2501) may receive a signal through a wireless channel and output the signal to the control unit (2502), and may transmit the signal output from the control unit (2502) through the wireless channel.

[0342] The control unit (2502) may control a series of procedures so that the base station (2500) can operate according to the embodiments of the present disclosure described above. For example, the control unit (2502) may perform or control the operation of the base station to perform at least one or a combination of methods according to the embodiments of the present disclosure. The control unit (2502) may include at least one processor. For example, the control unit (2502) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls an upper layer (e.g., an application).

[0343] The storage unit (2503) can store control information, data, control information or data received from a terminal, and can have an area for storing data required for controlling the control unit (2502) and data generated during control by the control unit (2502).

[0344] While the drawings illustrate different examples of user devices / base stations, various modifications to the drawings may be made. For example, the user devices / base stations may include any number of each component in any suitable arrangement. In general, the drawings do not limit the scope of the present disclosure to any particular configuration. Furthermore, while the drawings illustrate operating environments in which the various user devices / base stations described in this patent document may be utilized, such features may be utilized in any other suitable system.

[0345] While this disclosure has been described with exemplary embodiments, various modifications and variations will occur to those skilled in the art. It is intended that this disclosure encompass such modifications and variations as fall within the scope of the appended claims. The description in this application should not be construed as implying that any specific element, step, or function is essential to the scope of the claims. The scope of the patented subject matter is defined by the claims.

Claims

1. In a method performed by a terminal of a communication system, A step of receiving secondary cell (SCell) group configuration information from a base station, wherein the secondary cell group configuration information includes configuration information for a plurality of SCells; A step of receiving signaling related to activation of an on-demand SSB (synchronization signal block) on a specific SCell from the base station; and A method characterized by comprising the step of receiving the on-demand SSB on the specific SCell.

2. In paragraph 1, The signaling related to the activation of on-demand SSB on the above specific SCell corresponds to RRC (radio resource control) signaling, A method characterized in that activation of the specific SCell and activation of the on-demand SSB are indicated by the RRC signaling.

3. In paragraph 1, The signaling related to the activation of on-demand SSB on the above specific SCell corresponds to a MAC CE (medium access control control element), A method characterized in that activation of the on-demand SSB is indicated by the MAC CE.

4. In paragraph 1, A step of performing a measurement based on the above on-demand SSB; and A method characterized in that it further comprises a step of transmitting a CSI (channel state information) report or a measurement report to the base station.

5. In the method performed by the base station of the communication system, A step of transmitting secondary cell (SCell) group configuration information to a terminal, wherein the secondary cell group configuration information includes configuration information for a plurality of SCells; A step of transmitting signaling related to the activation of an on-demand SSB (synchronization signal block) on a specific SCell to the terminal; and A method characterized by comprising a step of transmitting the on-demand SSB on the specific SCell.

6. In paragraph 5, The signaling related to the activation of on-demand SSB on the above specific SCell corresponds to RRC (radio resource control) signaling, A method characterized in that activation of the specific SCell and activation of the on-demand SSB are indicated by the RRC signaling.

7. In paragraph 5, The signaling related to the activation of on-demand SSB on the above specific SCell corresponds to a MAC CE (medium access control control element), A method characterized in that activation of the on-demand SSB is indicated by the MAC CE.

8. In paragraph 5, Further comprising a step of receiving a CSI (channel state information) report or a measurement report from the terminal, A method characterized in that the above CSI report or the above measurement report is based on the on-demand SSB.

9. At the terminal of the communication system, Transmitter and receiver; and Receive secondary cell (SCell) group configuration information from a base station, wherein the secondary cell group configuration information includes configuration information for a plurality of SCells, Receive signaling related to activation of an on-demand SSB (synchronization signal block) on a specific SCell from the base station, and A terminal characterized by including a control unit configured to receive the on-demand SSB on the specific SCell.

10. In paragraph 9, The signaling related to the activation of on-demand SSB on the above specific SCell corresponds to RRC (radio resource control) signaling, A terminal characterized in that activation of the specific SCell and activation of the on-demand SSB are indicated by the RRC signaling.

11. In paragraph 9, The signaling related to the activation of on-demand SSB on the above specific SCell corresponds to a MAC CE (medium access control control element), A terminal characterized in that activation of the on-demand SSB is indicated by the MAC CE.

12. In paragraph 9, A terminal characterized in that the control unit is further configured to perform measurement based on the on-demand SSB and transmit a CSI (channel state information) report or a measurement report to the base station.

13. In the base station of the communication system, Transmitter and receiver; and Transmit secondary cell (SCell) group configuration information to a terminal, wherein the secondary cell group configuration information includes configuration information for multiple SCells, Transmit signaling related to the activation of an on-demand SSB (synchronization signal block) on a specific SCell to the terminal, and A base station characterized by including a control unit configured to transmit the on-demand SSB on the specific SCell.

14. In paragraph 13, The signaling related to the activation of the on-demand SSB on the specific SCell corresponds to RRC (radio resource control) signaling, and the activation of the specific SCell and the activation of the on-demand SSB are indicated by the RRC signaling, or A base station characterized in that the signaling related to the activation of on-demand SSB on the specific SCell corresponds to a medium access control control element (MAC CE), and the activation of the on-demand SSB is indicated by the MAC CE.

15. In paragraph 13, The control unit is further configured to receive a CSI (channel state information) report or a measurement report from the terminal, A base station, characterized in that the above CSI report or the above measurement report is based on the on-demand SSB.

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