Prach repetition method and device for coverage improvement and 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 in a wireless communication system comprises the steps of: receiving, from a base station, configuration information for a first physical random access channel occasion (RO) and configuration information for a second RO; determining physical random access channel (PRACH) repetition on the basis of a synchronization signal block (SSB); determining an RO set for the PRACH repetition; and performing the PRACH repetition transmission on the basis of the determined RO set.

Description

PRACH REPETITION method and device for coverage improvement and 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] According to various embodiments of the present disclosure, in a communication system, a base station may perform physical random access channel (PRACH) adaptation transmission to reduce energy consumption. At this time, the base station may configure and operate PRACH adaptation at two different PRACH occasions. More specifically, a PRACH occasion for initial access of a terminal that does not apply PRACH adaptation (e.g., a legacy terminal) and an additional PRACH occasion for a terminal that can apply PRACH adaptation (e.g., a Rel. 19 terminal) may be configured, and PRACH adaptation may be applied to the additional PRACH occasion. At this time, the terminal may perform a PRACH repetition operation through one or more different PRACH occasions configured above to improve uplink coverage.

[0010] According to various embodiments of the present disclosure, a terminal may receive a PRACH occasion and / or a PRACH occasion for PRACH adaptation from a base station through an existing PRACH configuration. Thereafter, the terminal may activate and / or deactivate the PRACH occasion configured for PRACH adaptation according to the configuration of the base station. At this time, the periodicity of the PRACH occasion or the number of time division multiplexing (TDM) / frequency division multiplexing (FDM) resources may be changed due to PRACH adaptation. Thereafter, PRACH repetition may be performed through the PRACH occasion resources.

[0011] According to various embodiments of the present disclosure, a PRACH occasion through an existing PRACH configuration and / or a PRACH occasion for PRACH adaptation may be configured.

[0012] According to various embodiments of the present disclosure, common PRACH repetition setting information and / or different PRACH repetition setting information may be set according to a PRACH occasion through an existing PRACH setting and a PRACH occasion for PRACH adaptation.

[0013] According to various embodiments of the present disclosure, a terminal may perform PRACH repetition by considering each PRACH occasion and / or a plurality of different PRACH occasions according to a setting from a base station.

[0014] According to various embodiments of the present disclosure, a method and device for operating a terminal / base station according to each of the above settings can be provided.

[0015] Various embodiments of the present disclosure may provide a configuration method through upper layer signaling (e.g., RRC signaling or system information block (SIB)) for applying PRACH adaptation. According to various embodiments of the present disclosure, based on the configuration information, a terminal may determine a PRACH occasion for PRACH transmission and / or an SSB that is QCLed (quasi co-located) with the corresponding PRACH occasion.

[0016] Various embodiments of the present disclosure can determine whether to transmit a PRACH repetition and the number of PRACH repetitions by comparing the RSRP of the DL pathloss of the SSB received in a PRACH occasion considering multiple PRACH configurations with a threshold for determining the set PRACH repetition.

[0017] 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.

[0018] A method according to one embodiment of the present disclosure is characterized by comprising a step of receiving a first control signal transmitted from a base station, a step of processing the received first control signal, a step of generating a second signal based on the processing, and a step of transmitting the generated second control signal to the base station, in a method for processing a control signal in a wireless communication system.

[0019] The various embodiments of the present disclosure described above are only some of the preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of the various embodiments of the present disclosure can be derived and understood by a person having ordinary skill in the art based on the detailed description to be described below.

[0020] According to one embodiment of the present disclosure, in a communication system, unnecessary energy consumption of a base station can be reduced by receiving signals and channels (e.g., PRACH) that are conventionally received periodically only when necessary through PRACH adaptation of a base station.

[0021] According to one embodiment of the present disclosure, a PRACH adaptation operation of a base station for energy saving of the base station and a corresponding terminal operation can be provided.

[0022] 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.

[0023] FIG. 1 illustrates the 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.

[0024] FIG. 2 illustrates a slot structure considered in a wireless communication system according to one embodiment of the present disclosure.

[0025] FIG. 3 illustrates an example of a time domain mapping structure and beam sweeping operation of a synchronization signal according to one embodiment of the present disclosure.

[0026] FIG. 4 illustrates a synchronization signal block considered in a wireless communication system according to one embodiment of the present disclosure.

[0027] FIG. 5 illustrates various transmission cases 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.

[0028] FIG. 6 illustrates transmission cases 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.

[0029] FIG. 7 illustrates transmission cases 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.

[0030] FIG. 8 illustrates 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.

[0031] FIG. 9 illustrates an example of channel estimation using DMRS received on one PUSCH in a time band of a wireless communication system according to one embodiment of the present disclosure.

[0032] FIG. 10 illustrates a method for re-establishing SSB transmission via dynamic signaling in a wireless communication system according to one embodiment of the present disclosure.

[0033] FIG. 11 illustrates a method for resetting BWP and BW through dynamic signaling in a wireless communication system according to one embodiment of the present disclosure.

[0034] FIG. 12 illustrates a method for re-establishing discontinuous reception (DRX) through dynamic signaling in a wireless communication system according to one embodiment of the present disclosure.

[0035] FIG. 13 illustrates an example of a DTx method for base station energy saving according to one embodiment of the present disclosure.

[0036] FIG. 14 illustrates an example of an operation of a base station according to a gNB wake-up signal according to one embodiment of the present disclosure.

[0037] FIG. 15 illustrates an antenna adaptation method of a base station for energy saving in a wireless communication system according to one embodiment of the present disclosure.

[0038] FIGS. 16A and 16B are diagrams illustrating an example of a PRACH adaptation operation of a base station according to an embodiment of the present disclosure.

[0039] FIG. 17 is a diagram illustrating an example of a PRACH adaptation operation of a base station according to one embodiment of the present disclosure.

[0040] FIG. 18 is a diagram illustrating an example of a PRACH repetition operation of a base station according to one embodiment of the present disclosure.

[0041] FIG. 19 is a diagram illustrating an example of a PRACH repetition operation of a base station according to one embodiment of the present disclosure.

[0042] FIG. 20 is a diagram illustrating an example of a PRACH adaptation operation of a base station and a terminal according to one embodiment of the present disclosure.

[0043] FIG. 21 is a diagram illustrating an example of a PRACH adaptation operation of a base station and a terminal according to one embodiment of the present disclosure.

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

[0045] FIG. 23 is a block diagram of a base station according to one embodiment of the present disclosure.

[0046] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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 skilled in the art.

[0052] 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).

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] In the LTE system, which is a representative example of a broadband wireless communication system, the downlink (DL) adopts the orthogonal frequency division multiplexing (OFDM) method, and the uplink (UL) adopts the single carrier frequency division multiple access (SC-FDMA) method. The uplink refers to a wireless link in which a terminal (hereinafter referred to as user equipment (UE)) (or mobile station (MS)) transmits data or control signals to a base station (eNode B (eNB) or base station (BS)), and the downlink refers to a wireless link in which a base station transmits data or control signals to a terminal (UE). In addition, the aforementioned multiple access method typically allocates and operates time-frequency resources for transmitting data or control information to each user so that they do not overlap, that is, so as to achieve orthogonality, thereby distinguishing the data or control information of each user.

[0058] 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).

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] FIG. 1 illustrates the 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.

[0065] 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 (Orthogonal Frequency Division Multiplexing) 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. Indicates the number of subcarriers per resource block (RB) in the frequency domain. (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).

[0066] FIG. 2 illustrates a slot structure considered in a wireless communication system according to one embodiment of the present disclosure.

[0067] 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).

[0068] 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 in below.

[0069]

[0070] In a 5G wireless 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).

[0071] In the initial access phase when 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 (System Information Block, SIB) transmitted by the base station. The cell-common transmission and reception-related control information may include random access-related control information, paging-related control information, and common control information for various physical channels.

[0072] 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.

[0073] FIG. 3 illustrates an example of a time domain mapping structure and beam sweeping operation of a synchronization signal according to one embodiment of the present disclosure.

[0074] For illustrative purposes, the following components can be defined:

[0075] - PSS (Primary Synchronization Signal): This signal serves as the basis for DL ​​time / frequency synchronization and provides some cell ID information.

[0076] - 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.

[0077] - PBCH (Physical Broadcast Channel): Provides MIB (Master Information Block), which is essential system information required for transmission and reception of data channels and control channels of the terminal. The essential system information may include search space-related control information indicating radio resource mapping information of the control channel, scheduling control information for a separate data channel that transmits system information, and SFN (System Frame Number), which is a frame-unit index that serves as a timing reference.

[0078] - SS / PBCH Block (Synchronization Signal / PBCH Block or SSB): An SS / PBCH block consists of N OFDM symbols and is a combination of PSS, SSS, PBCH, etc. In a system where beam sweeping technology is applied, the SS / PBCH block is the minimum unit to which beam sweeping is applied. In a 5G system, N can be 4. The base station can transmit up to L SS / PBCH blocks, and the L SS / PBCH blocks are mapped within a half frame (0.5 ms). In addition, the L SS / PBCH blocks are periodically repeated in units of a predetermined period P. The period P can be notified to the terminal by the base station through signaling. If there is no separate signaling for the period P, the terminal applies a pre-agreed default value.

[0079] 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.

[0080] 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.

[0081] Below, the cell initial access operation procedure of a 5G wireless communication system will be described in more detail with reference to drawings.

[0082] 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.

[0083] FIG. 4 illustrates a synchronization signal block considered in a wireless communication system according to one embodiment of the present disclosure.

[0084] Referring to FIG. 4, a synchronization signal block (SS block) (400) may include a PSS (401), an SSS (403), and a PBCH (Physical Broadcast Channel) (402).

[0085] 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 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 PBCH payload and 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 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 of PBCH DMRS indicate a synchronization signal block index, and in a frequency band above 6 GHz, a total of 6 bits, including 3 bits obtained through decoding of PBCH DMRS and 3 bits obtained through PBCH decoding included in the PBCH payload, may indicate a synchronization signal block index including the PBCH. - PDCCH (physical downlink control channel) configuration information: The subcarrier spacing of the common downlink control channel may be indicated through 1 bit (subCarrierSpacingCommon) in the MIB, and time-frequency resource configuration information of CORESET (control resource set) and search space (SS) may be indicated through 8 bits (pdcch-ConfigSIB1). - SFN (system frame number): 6 bits (systemFrameNumber) in the MIB may be used to indicate a part of the SFN. The 4 least significant bits (LSBs) of the SFN are included in the PBCH payload, and the terminal can indirectly obtain them through PBCH decoding.

[0091] - 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.

[0092] 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.

[0093] 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.

[0094] FIG. 5 illustrates various transmission cases 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.

[0095] Referring to FIG. 5, in a 5G communication system, a subcarrier spacing (SCS) (520) of 15 kHz and a subcarrier spacing (SCS) (530, 540) of 30 kHz may be used for transmission of a synchronization signal block in a frequency band below 6 GHz (or, FR1 (frequency range 1), e.g., 410 MHz-7125 MHz). 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.

[0096] 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.

[0097] 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.

[0098] In case #2 (502) at 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 one 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.

[0099] 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.

[0100] 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 one 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.

[0101] 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.

[0102] FIG. 6 illustrates transmission cases 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.

[0103] Referring to FIG. 6, in a wireless communication system, in a frequency band of 6 GHz or higher (or, FR2, e.g., 24250 MHz-52000 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.

[0104] 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.

[0105] 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.

[0106] 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).

[0107] 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.

[0108] 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.

[0109] FIG. 7 illustrates transmission cases 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.

[0110] 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).

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] - 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 (eg 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.

[0117] Below, we describe a method for setting measurement times for Radio Resource Management (RRM) based on a synchronization signal block (SS block or SSB) in a 5G wireless communication system. A terminal configures MeasObjectNR in MeasObjectToAddModList via higher-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.

[0118]

[0119]

[0120] The terms in can perform the following functions, but are not limited thereto.

[0121] -ssbFrequency:You can set the frequency of the synchronization signal associated with MeasObjectNR.

[0122] -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.

[0123] -smtc1: Indicates SS / PBCH block measurement timing configuration, and can set the primary measurement timing configuration and the timing offset and duration for SSB.

[0124] -smtc2:pci-List allows you to set the secondary measurement timing configuration for SSBs associated with MeasObjectNRs with PCIs listed in pci-list.

[0125] 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 change and NR PCell change, and SCellConfig for NR SCell addition.

[0126] For SSB measurement, the terminal can set the first SS / PBCH block measurement timing configuration (SMTC) according to periodictiyAndOffset (providing Periodicity and Offset) through smtc1 set through upper layer signaling. In one embodiment, the first subframe of each SMTC occasion can start from the system frame number (SFN) and the subframe of SpCell that satisfy the conditions of Table 5 below.

[0127]

[0128] If smtc2 is configured, the UE 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 UE 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 UE may not consider SSB transmitted in subframes other than SMTC occasions for SSB-based RRM measurement at the configured ssbFrequency.

[0129] A base station can utilize various multi-TRP (transmit / receive point) operation methods, depending on serving cell configuration and physical cell identifier (PCI) settings. Among these, when two physically separated TRPs have different PCIs, there are two possible methods for operating the two TRPs.

[0130] [Operation Method 1]

[0131] Two TRPs with different PCIs can be operated with two serving cell configurations.

[0132] The base station can configure channels and signals transmitted from different TRPs by including them in different serving cell configurations through [Operation Method 1]. That is, each TRP has an independent serving cell configuration, and the frequency band values ​​FrequencyInfoDLs indicated by DownlinkConfigCommon in each serving cell configuration can indicate at least some overlapping bands. Since the above multiple TRPs operate based on multiple ServCellIndexes (e.g., ServCellIndex #1 and ServCellIndex #2), it is possible for each TRP to use a separate PCI. That is, the base station can allocate one PCI per ServCellIndex.

[0133] In this case, if multiple SSBs are transmitted from TRP 1 and TRP 2, and the SSBs have different PCIs (e.g., PCI #1 and PCI #2), the base station can appropriately select the value of ServCellIndex indicated by the cell parameter in QCL-Info to map the PCI suitable for each TRP and designate the SSB transmitted from either TRP 1 or TRP 2 as the source reference RS of the QCL configuration information. However, this configuration applies one serving cell configuration that can be used for carrier aggregation (CA) of the terminal to multiple TRPs, which has the problem of limiting the degree of freedom of CA configuration or increasing the signaling burden.

[0134] [Operation Method 2]

[0135] Two TRPs with different PCIs can be operated with one serving cell configuration.

[0136] The base station can configure channels and signals transmitted in different TRPs through a single serving cell configuration using [Operation Method 2]. Since the terminal operates based on a single ServCellIndex (e.g., ServCellIndex #1), it is impossible for it to recognize the PCI (e.g., PCI #2) allocated to the second TRP. [Operation Method 1] may have greater freedom in CA configuration compared to the above-described [Operation Method 1], but if multiple SSBs are transmitted in TRP 1 and TRP 2, the SSBs may have different PCIs (e.g., PCI #1 and PCI #2), and the base station may not be able to map the PCI (e.g., PCI #2) of the second TRP through the ServCellIndex indicated by the cell parameter in the QCL-Info. The base station may only be able to designate the SSB transmitted in TRP 1 as the source reference RS of the QCL configuration information, but may not be able to designate the SSB transmitted in TRP 2.

[0137] As described above, [Operation Method 1] can perform multi-TRP operation for two TRPs with different PCIs through additional serving cell configuration without additional standard support, but [Operation Method 2] can operate based on the following additional terminal capability report and base station configuration information.

[0138] Terminal capability reporting for [Operation Method 2]

[0139] - A terminal can report to the base station via upper layer signaling that it can configure additional PCIs other than the PCI of the serving cell, through the terminal capability. The terminal capability may include two independent numbers, X1 and X2, or each X1 and X2 may be reported as an independent terminal capability.

[0140] - X1 means the maximum number of additional PCIs that can be set for the terminal, and the PCI may be different from the PCI of the serving cell. In this case, the time domain position and periodicity of the SSB corresponding to the additional PCI may be the same as the SSB of the serving cell.

[0141] - X2 means the maximum number of additional PCIs that can be set for the terminal, and the PCI at this time may be different from the PCI of the serving cell, and the time domain position and periodicity of the SSB corresponding to the additional PCI may be different from the SSB corresponding to the PCI reported as X1.

[0142] - By definition, the PCIs corresponding to the values ​​reported by X1 and X2 cannot be set simultaneously.

[0143] - The values ​​reported as X1 and X2 through the terminal capability report can each have an integer value from 0 to 7.

[0144] - The values ​​reported as X1 and X2 may have different values ​​reported in FR1 and FR2.

[0145] Regarding upper layer signaling settings for [Operation Method 2]

[0146] - The terminal may receive from the base station the upper layer signaling SSB-MTCAdditionalPCI-r17 based on the terminal capability report described above, and the upper layer signaling may include at least a plurality of additional PCIs having different values ​​from the serving cell, SSB transmission power corresponding to each additional PCI, and ssb-PositionInBurst corresponding to each additional PCI, and the maximum number of additional PCIs that can be set may be 7.

[0147] - The terminal can assume that the SSB corresponding to the additional PCI of a different value from the serving cell has the same center frequency, subcarrier spacing, and subframe number offset as the SSB of the serving cell.

[0148] - The terminal can assume that the reference RS (e.g., SSB or CSI-RS) corresponding to the PCI of the serving cell is always connected to the activated TCI state, and in case of an additionally configured PCI with a different value from the serving cell, when there is one or more PCIs, it can assume that only one PCI among those PCIs is connected to the activated TCI state.

[0149] - If a terminal is configured with two different coresetPoolIndexes, and a reference RS corresponding to a serving cell PCI is connected to one or more activated TCI states, and a reference RS corresponding to an additionally configured PCI having a different value from the serving cell is connected to one or more activated TCI states, the terminal can expect that the activated TCI state(s) connected to the serving cell PCI will be connected to one of the two coresetPoolIndexes, and the activated TCI state(s) connected to the additionally configured PCI having a different value from the serving cell will be connected to the remaining one coresetPoolIndex.

[0150] The terminal capability report and the upper layer signaling of the base station for the above-described [Operation Method 2] can set an additional PCI with a different value from the PCI of the serving cell. If the above setting does not exist, the SSB corresponding to the additional PCI with a different value from the PCI of the serving cell that cannot be designated as the source reference RS can be used for the purpose of designating the source reference RS of the QCL configuration information. In addition, unlike the SSB that can be set for purposes such as RRM, mobility, or handover, like the configuration information for the SSB that can be set in the upper layer signaling smtc1 and smtc2, it can be used to serve as a QCL source RS to support multiple TRP operations with different PCIs.

[0151] Next, we will specifically explain DMRS (demodulation reference signal), one of the reference signals in the 5G system.

[0152] 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 using the reference signal. The term DMRS is only provided as a specific example to easily explain the technical content of the present disclosure and 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.

[0153] FIG. 8 illustrates 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.

[0154] In 5G systems, two DMRS patterns can be supported.

[0155] Referring to Fig. 8, DMRS type1 (801, 802) is illustrated, and specifically, a 1 symbol pattern (801) and a 2 symbol pattern (802) are illustrated. DMRS type1 (801, 802) is a DMRS pattern of a comb 2 structure and can be composed of two CDM groups, and different CDM groups can be FDMed.

[0156] In the 1 symbol pattern (801), frequency-based CDM is applied to the same CDM group to distinguish two DMRS ports, and thus a total of four orthogonal DMRS ports can 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), time / frequency-based CDM is applied to the same CDM group to distinguish four DMRS ports, and thus a total of eight orthogonal DMRS ports can 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).

[0157] 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.

[0158] 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).

[0159] 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 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, and in the case of DFT-S-OFDM (discrete Fourier transform spread OFDM), only DMRS type 1 (801, 802) among the above-described DMRS patterns can be supported in the UL.

[0160] Additionally, support may be provided for setting 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 set, 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 set, it may be assumed that the additional DMRS has the same DMRS information as the front-loaded DMRS.

[0161] In one embodiment, the downlink DMRS settings described above can be set via RRC signaling as shown in below.

[0162]

[0163] 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).

[0164] Additionally, the above-mentioned uplink DMRS settings can be set through RRC signaling as shown in below.

[0165]

[0166] 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.

[0167] FIG. 9 illustrates an example of channel estimation using DMRS received on one PUSCH in a time band of a wireless communication system according to one embodiment of the present disclosure.

[0168] 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 utilizing PRB (physical resource blocks) bundling linked to the system band in the frequency band. In addition, in the time unit, the channel can be estimated by assuming that only DMRS received on one PUSCH has the same precoding.

[0169] 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 (physical downlink shared channel; PDSCH) and an uplink data channel (physical uplink shared channel; PUSCH) to a terminal through higher layer signaling (e.g., RRC signaling).

[0170] 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 at which a PDSCH or a PUSCH is scheduled within a slot, and a mapping type of a PDSCH or a PUSCH.

[0171] In one embodiment, time domain resource allocation information for PDSCH can be set to a terminal through RRC signaling as shown in below.

[0172]

[0173] 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.

[0174] In one embodiment, time domain resource allocation information for PUSCH can be set to a terminal through RRC signaling as shown in below.

[0175]

[0176] 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.

[0177] The base station can 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 a 'time domain resource allocation' field in the DCI). The terminal can obtain time domain resource allocation information for the PDSCH or PUSCH based on the DCI received from the base station.

[0178] The following describes the transmission of the physical uplink shared channel (PUSCH) in a 5G system. PUSCH transmission can be dynamically scheduled by an UL grant in the DCI (e.g., referred to as dynamic grant (DG)-PUSCH) or by configured grant Type 1 or configured grant Type 2 (e.g., referred to as configured grant (CG)-PUSCH). Dynamic scheduling for PUSCH transmission can be indicated, for example, by DCI format 0_0 or 0_1.

[0179] 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.

[0180] 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 , 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 . For example, if a terminal is provided with transformPrecoder in configuredGrantConfig, which is a higher layer signaling of , the terminal can apply tp-pi2BPSK in pusch-Config, which is a higher layer signaling of , to PUSCH transmission operated by configured grant.

[0181]

[0182]

[0183] 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 upper signaling, pusch-Config in [Table 7], 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.

[0184] 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.

[0185]

[0186]

[0187] 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).

[0188] 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-level 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-level signaling precodingAndNumberOfLayers. The TPMI may be used to indicate a precoder applied to the PUSCH transmission.

[0189] The 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 the upper signaling SRS-Config. In codebook-based PUSCH transmission, the UE can determine the codebook subset based on the TPMI and the codebookSubset in the upper signaling pusch-Config. In one embodiment, the codebookSubset in the upper signaling pusch-Config can be set to one of 'fullyAndPartialAndNonCoherent', 'partialAndNonCoherent', or 'nonCoherent' based on the UE capability reported by the UE to the base station.

[0190] If the UE reports 'partialAndNonCoherent' as the UE capability, the UE may not expect the value of the upper signaling codebookSubset to be set to 'fullyAndPartialAndNonCoherent'. Also, if the UE reports 'nonCoherent' as the UE capability, the UE may not expect the value of the upper signaling codebookSubset to be set to 'fullyAndPartialAndNonCoherent' or 'partialAndNonCoherent'. If nrofSRS-Ports in the upper signaling SRS-ResourceSet indicates two SRS antenna ports, the UE may not expect the value of the upper signaling codebookSubset to be set to 'partialAndNonCoherent'.

[0191] A terminal can be configured with one SRS resource set in which the usage value in the upper signaling SRS-ResourceSet is set to 'codebook', and one SRS resource within the 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 signaling SRS-ResourceSet is set to 'codebook', the terminal can expect that the value of nrofSRS-Ports in the upper signaling SRS-Resource is set to the same value for all SRS resources.

[0192] The terminal transmits to the base station one or more SRS resources included in the SRS resource set in which the usage value is set to 'codebook' according to upper signaling, 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.

[0193] 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 signaling SRS-ResourceSet is set to 'nonCodebook', the UE can be scheduled for non-codebook-based PUSCH transmission via DCI format 0_1.

[0194] For an SRS resource set in which the usage value in the upper 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.

[0195] If the value of resourceType in the upper signaling SRS-ResourceSet 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, if 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. If 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 in the scheduled subcarriers may not be set to QCL-TypeD.

[0196] 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 in the upper signaling SRS-ResourceSet. For non-codebook-based transmission, the UE may not expect that the upper signaling spatialRelationInfo for the SRS resource and the associatedCSI-RS in the upper signaling SRS-ResourceSet are configured together.

[0197] 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-level 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 signaling SRS-ResourceSet can be set, and up to four SRS resources for non-codebook-based PUSCH transmission can be set.

[0198] 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.

[0199] 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.

[0200] PUSCH repetitive transmission type A

[0201] - 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.

[0202] - 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 below, a redundancy version can be applied according to the redundancy version pattern set for each nth PUSCH transmission occasion.

[0203] PUSCH repetitive transmission type B

[0204] - 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 to the terminal through upper 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.

[0205] - 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 PUSCH repetitive 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,…,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. indicates the slot in which the PUSCH transmission starts. can represent the number of symbols per slot.

[0206] - 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). As an 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.

[0207] - 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.

[0208] TB processing over multiple slots (TBoMS)

[0209] - 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.

[0210] - 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.

[0211] 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 the following , a redundancy version can be applied according to a redundancy version pattern set for each nth PUSCH transmission occasion.

[0212]

[0213] Below, we describe a method for determining uplink available slots for single or multiple PUSCH transmissions in a 5G system.

[0214] 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.

[0215] Below, we describe a method for reducing SSB density through dynamic signaling to save base station energy in 5G systems.

[0216] FIG. 10 illustrates a method for re-establishing SSB transmission via dynamic signaling in a wireless communication system according to one embodiment of the present disclosure.

[0217] 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 bitmap '1010xxxx' (1004) through Group / Cell common DCI (1003) having 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, transmission of SS block#1 (1005) and SSblock#3 (1006) can be canceled based on the bitmap (1004) set by Group / Cell common DCI. Fig. 10 illustrates a method (1001) for resetting SSB transmission through bitmap-based group / Cell common DCI.

[0218] In addition, the base station can reset the ssb-periodicity set through upper layer signaling via Group / Cell common DCI. In addition, by additionally setting timer information to indicate the application time of Group / Cell common DCI, SSB can be transmitted through SSB transmission information reset to Group / Cell common DCI during the set timer. Afterwards, when the timer expires, the base station can operate with the SSB transmission information set through the existing upper layer signaling. This can change the setting from normal mode to energy saving mode through the timer, and thereby 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 Duration information. In this case, the terminal may not monitor SSB during the Duration from the moment when the Group / Cell common DCI is received to the moment when the Offset is applied.

[0219] Below, we describe a BWP or BW adaptation method through dynamic signaling for base station energy saving in 5G systems.

[0220] FIG. 11 illustrates a method for resetting BWP and BW through dynamic signaling in a wireless communication system according to one embodiment of the present disclosure.

[0221] 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, 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 the Group common DCI and the 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.

[0222] 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.

[0223] - MIB (Master Information Block)

[0224] - SIB (System Information Block) or SIB

[0225] - RRC (Radio Resource Control)

[0226] - MAC (Medium Access Control) CE (Control Element)

[0227] 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.

[0228] - PDCCH (Physical Downlink Control Channel)

[0229] - DCI (Downlink Control Information)

[0230] - UE-specific DCI

[0231] - Group common DCI

[0232] - Common DCI

[0233] - Scheduling DCI (e.g. DCI used for scheduling downlink or uplink data)

[0234] - Non-scheduled DCI (e.g. DCI not intended for scheduling downlink or uplink data)

[0235] - PUCCH (Physical Uplink Control Channel)

[0236] - UCI (Uplink Control Information)

[0237] 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.

[0238] Below, a DRX alignment method through dynamic signaling for base station energy saving in a 5G system is described.

[0239] FIG. 12 illustrates a method for re-establishing DRX through dynamic signaling in a wireless communication system according to one embodiment of the present disclosure.

[0240] Referring to FIG. 12, the base station can configure DRX in a UE-specific manner through higher layer signaling. For example, each terminal can be configured with different drx-LongCycle (1202) or drx-ShortCycle, drx-onDurationTimer (1203), and drx-InactivityTimer (1204). Afterwards, the base station can configure UE-specific DRX settings in a UE group-specific or cell-specific manner through L1 signaling (1201) for energy saving. Through this, the base station can obtain the same effect of saving power as the terminal through DRX for energy saving.

[0241] Below is an example illustrating the discontinuous transmission (DTx) operation for reducing energy consumption of a base station in a 5G system.

[0242] FIG. 13 is a diagram illustrating a DTx method for base station energy saving according to one embodiment of the present disclosure.

[0243] Referring to FIG. 13, the base station can configure DTx for energy saving through upper layer signaling (e.g., new system information block (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 reference signal for measuring PDCCH for scheduling DL SCH for DTx operation, RRM measurement, beam management, and path loss, dtx-InactivityTimer (1306) for receiving PDSCH after receiving PDCCH for scheduling DL SCH, dtx-offset (1304) for setting an offset between dtx-onDurationTimer after SS setting information for synchronization before dtx-onDurationTimer, 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. During the DTx operation, the base station considers the transmitter to be off (or inactive), and therefore may not transmit DL CCH, SCH, and DL RS. That is, the base station can transmit downlink (e.g., PDCCH, PDSCH, RS, etc.) only during SS, dtx-onDurationTimer, and dtx-InactivityTimer during the DTx operation. At this time, SS-gapbetweenBurst (the gap between SS bursts in the time domain) or the number of SS bursts can be additionally configured as additional information of the configured SS.

[0244] 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.

[0245] FIG. 14 illustrates an example illustrating the operation of a base station according to a gNB WUS according to one embodiment of the present disclosure.

[0246] 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 (wake-up signal) (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 perform control and data transmission. 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 save energy, and at the same time, the terminal can improve latency.

[0247] At this time, the base station can set a WUS occasion for receiving the gNB WUS and a Sync RS for synchronization before the terminal transmits the gNB WUS. At this time, SSB, TRS, Light SSB (PSS+SSS), consecutive SSBs, or new RS (continuous PSS + SSS) can be considered as the Sync RS, and PRACH, PUCCH with SR, or a sequence-based signal can be considered as the WUS. The Sync RS (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 periodicity (1405). In the case of FIG. 14, one embodiment is described with 1-to-1 mapping of the Sync RS and the WUS occasion as an example, but the present disclosure is not limited thereto. For example, the Sync and the WUS occasion can be N-to-1 mapped, 1-to-N mapped, or N-to-M mapped.

[0248] Below, a method for dynamically turning on / off spatial domain elements (i.e., antennas, power amplifiers (PAs) or TxRUs (transceiver units or transmission radio units)) of a base station to save base station energy in a 5G system is described.

[0249] FIG. 15 is a diagram illustrating an antenna adaptation method of a base station for energy saving in a wireless communication system according to one embodiment of the present disclosure.

[0250] 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 adjust the number of activated Tx antennas for each UE group or UE and transmit Tx. At this time, the base station can set information including one or more of beam information according to antenna on / off or reference signal information (e.g., one or more of CSI resource, CSI resource set, or CSI report) 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 the BWP change. 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 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.

[0251] More specifically, the base station can apply multiple types (e.g., two types) of SD adaptation for energy saving (1502). For example, the multiple types can include Type 1 SD adaptation (1503) and Type 2 SD adaptation (1504).

[0252] 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., tx power, 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.).

[0253] 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 the physical antenna elements per port (1504). At this time, the RF characteristics of each port can be different. 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.

[0254] Below, the PRACH adaptation operation or PRACH occasion setting with respect to a base station or terminal is described for energy saving of a base station in a 5G system.

[0255] FIGS. 16A and 16B are diagrams illustrating an example of a PRACH adaptation operation of a base station according to an embodiment of the present disclosure.

[0256] In one embodiment, a base station may configure PRACH adaptation for energy saving. In this case, as illustrated in FIGS. 16a and 16b , the PRACH periodicity may be changed by considering the overall mobility and number of terminals as a method of PRACH adaptation (1601). Alternatively, when the number of terminals considering a specific beam is zero or relatively less than a certain number, the base station may apply PRACH adaptation by turning off a specific PRACH occasion (RO) associated with the beam (e.g., SSB) (1602).

[0257] More specifically, referring to Case 1 of FIG. 16a, the UE can be configured with two PRACH occasions, PRACH occasion#0 (1602) and PRACH occasion#1 (1603), from the base station through higher layer signaling. At this time, a specific PRACH occasion#0 (1602) may be configured as a resource always used for PRACH transmission without considering PRACH adaptation. On the other hand, for a specific purpose such as energy saving of the base station, according to one embodiment, a specific PRACH occasion#1 (1603) may be used as an occasion to which PRACH adaptation is applicable. The two PRACH occasions (1602, 1603) are configured through different higher layer signaling and can be operated simultaneously.

[0258] According to one embodiment, based on the configured PRACH occasion#1(1603), if the number of currently activated terminals or traffic requests is less than a specific number or depending on the relative change, the base station can turn off or deactivate PRACH occasion#1(1603) to perform initial access and PRACH reception operations only through PRACH occasion#0(1602) having a long period of 20 ms. On the other hand, if the number of terminals camping at the base station increases above a specific number or depending on the relative change, the base station can turn on (or activate) PRACH occasion#1(1603) to perform initial access and PRACH reception operations through a PRACH occasion having a shorter period (e.g., 10 ms).

[0259] According to one embodiment, the base station may apply PRACH adaptation using higher layer signaling (e.g., SIB or RRC message, etc.) and / or L1 signaling (e.g., DCI), and in the case of PRACH occasion#1 (1603), the periodicity may be changed and operated according to PRACH adaptation.

[0260] According to Case 2 of FIG. 16b, a terminal can be configured with two PRACH occasions #0 (1605) and PRACH occasion #1 (1606) from a base station through higher layer signaling. At this time, a specific PRACH occasion #0 (1605) can be configured as a resource always used for PRACH transmission without considering PRACH adaptation. On the other hand, for a specific purpose such as energy saving of the base station, according to one embodiment, a specific PRACH occasion #1 (1606) can be used as an occasion to which PRACH adaptation is applicable. Thereafter, if the base station determines that the number of terminals in specific SSB #0 and SSB #1 is less than or equal to a specific number, the base station can configure and / or instruct to turn off or deactivate the PRACH occasion (1607) of PRACH occasion #1 associated with the corresponding SSB #0 and SSB #1 through higher layer signaling and L1 signaling. According to one embodiment, in the case of the base station's judgment method in the above operation, the judgment can be made based on the frequency of receiving PRACH through PRACH occasion during a specific period.

[0261] The above-described methods are not limited to one embodiment of the present disclosure and can operate with N PRACH occasion settings and various periodicities and SSB patterns in ssb-positionInburst. Through the above methods, the base station can apply PRACH adaptation and achieve energy-saving effects while ensuring contention performance during PRACH transmission for the initial access of the terminal.

[0262] FIG. 17 is a diagram illustrating an example of a PRACH adaptation operation of a base station according to one embodiment of the present disclosure.

[0263] Referring to FIG. 17, the base station can configure two different PRACH configurations to the terminal through higher-layer signaling. More specifically, a long-period PRACH occasion #0 (1701) and a short-period PRACH occasion #1 (1702) for applying PRACH adaptation can be configured (e.g., a network energy savings (NES) PRACH occasion). In this case, a valid PRACH occasion for PRACH transmission can be determined using one of the methods exemplified below.

[0264] [Method 1]

[0265] Method 1 proposes a PRACH transmission method that selects a PRACH occasion and PRACH configuration based on the earliest (or closest) PRACH occasion.

[0266] A UE can determine the PRACH occasion that is set first for PRACH transmission and perform a PRACH transmission operation based on the PRACH configuration that sets the corresponding PRACH occasion. More specifically, referring to FIG. 17, for example, when UE#0 performs a PRACH transmission, UE#0 can select the closest PRACH occasion RO#0 (1703) and perform a PRACH transmission operation through PRACH occasions set as PRACH configuration#0 corresponding to the PRACH occasion RO#0 (1703) (1704). On the other hand, for example, UE#1 can select RO#1 (1705) as the closest PRACH occasion for PRACH transmission. Thereafter, UE#1 can perform a PRACH transmission operation based on PRACH configuration#1 corresponding to RO#1 (1705) (1706). Through this method, the UE can reduce the complexity of the UE by performing a PRACH transmission operation based on a single PRACH configuration setting (or information). Additionally, latency performance can be guaranteed by selecting the fastest PRACH occasion and operating.

[0267] [Method 2]

[0268] Method 2 proposes a PRACH transmission method that considers all PRACH occasions based on multiple PRACH configurations.

[0269] The terminal can determine a valid occasion for PRACH transmission and transmit the PRACH by considering multiple PRACH configurations #0 and #1 configured through upper layer signaling from the base station for PRACH transmission (1707). At this time, the terminal can transmit the PRACH based on a greater number of PRACH occasions, thereby improving contention between PRACH transmissions.

[0270] As in the above methods, the base station can configure one or more PRACH configurations for PRACH adaptation and receive PRACHs from the terminal based on these configurations. At this time, the base station can select / activate / deactivate some of the multiple PRACH configurations through upper layer signaling and / or L1 signaling, thereby indicating PRACH adaptation.

[0271] Below, PRACH configuration methods to support the above operations are described.

[0272] In one embodiment, the base station may configure one or more PRACH configurations to the terminal via higher-layer signaling (e.g., system information block or RRC signaling). At this time, the base station may configure a PRACH occasion corresponding to the default operation using existing PRACH configuration configuration information. PRACH adaptation may not be applied to the corresponding PRACH occasion.

[0273] A base station can configure one or more additional PRACH configurations for specific purposes, such as energy saving. More specifically, the PRACH configuration-related information illustrated in Table 13 below can be additionally configured. At this time, an additional PRACH configuration ID can be newly added to distinguish between one or more PRACH configurations or for PRACH adaptation.

[0274]

[0275]

[0276] Thereafter, the base station can select or activate or deactivate one or more of the above one or more PRACH configurations through SIB update, RRC reconfiguration, MAC CE, cell-specific / group common DCI and / or UE-specific DCI.

[0277] In one embodiment, scheduling of the above configuration information may be indicated via CORESET#0, and in the case of DCI used for PRACH adaptation, it may be transmitted with a new RNTI for NES.

[0278] Considering the above configuration information, some information may be newly included in the existing RRC message as information for PRACH adaptation (e.g., Rel-19 configuration). According to one embodiment, when the base station selects, activates, or configures one or more PRACH configurations for PRACH adaptation and PRACH transmission, the total number of PRACH preambles considered for PRACH transmission and / or the total number of PRACH occasions that can be FDMed and / or the total number of PRACH resources may be limited so as not to exceed values ​​that can be configured through the existing PRACH configuration. For example, the number of PRACH preambles may be limited to not exceed 63 (e.g., min(63, sum(configured PRACH preambles))), and the maximum number of PRACH occasions that can be FDMed simultaneously may be limited to 8 (e.g., min(8, sum(configured msg1-FDMs))). The above-described content is an embodiment of the present disclosure and may be applied to all values ​​that can be configured through the existing PRACH configuration.

[0279] Additionally, in one embodiment, the maximum value may be changed for terminals with Rel-19 NES capability. Furthermore, the maximum value, etc. may be changed depending on terminals with similar capabilities.

[0280] Additionally, according to one embodiment, an additional PRACH configuration to support two step RA operation may be applied for PRACH adaptation.

[0281] FIG. 18 is a diagram illustrating an example of a PRACH repetition operation of a base station according to one embodiment of the present disclosure.

[0282] Referring to FIG. 18, the base station can set two different PRACH configurations to the terminal through upper layer signaling. For example, the base station can set PRACH occasion#0 (1801) with a relatively long period and PRACH occasion#1 (1802) with a relatively short period for applying PRACH adaptation. At this time, depending on the two PRACH configuration settings, the PRACH occasions can overlap in the time domain, the frequency domain, each of the time / frequency domains, or both domains, or can be TDM / FDM.

[0283] According to one embodiment, the base station may set configuration information for PRACH repetition (e.g., thresholds for each PRACH repetition number) to the terminal. At this time, if the base station sets the PRACH repetition considering the two PRACH configurations set in FIG. 18, the terminal may determine a set of PRACH occasions for PRACH repetition by using TDMed ROs in the same frequency band. The terminal may use the configuration information of the PRACH repetition selected for PRACH transmission according to the PRACH repetition configuration linked to the closest (earliest) PRACH occasion where the terminal can transmit PRACH, or may determine it as a value set based on the maximum transmittable number of PRACH repetitions of different PRACH configurations corresponding to the two PRACH occasions.

[0284] According to one embodiment, the value of the number of PRACH repetitions for the actual PRACH repetition may be determined by the terminal as the number of PRACH repetitions determined by comparing the DL pathloss RSRP measured via SSB with a threshold.

[0285] In one embodiment, the base station may configure common PRACH repetition information based on the capabilities of the terminal. For example, for a terminal without PRACH adaptation capability, the base station may not configure PRACH repetitions or may set a threshold to allow a smaller number of PRACH repetitions. Conversely, for a terminal with PRACH adaptation capability, the threshold may be set to allow a larger number of PRACH repetitions.

[0286] After the above setting and determination of PRACH repetition according to one embodiment, the UE can redefine the index of the PRACH occasion in the PRACH occasion set for transmitting the PRACH repetition. For example, in relation to indexing or reindexing, in FIG. 18, when PRACH repetition is performed for each PRACH configuration, the PRACH occasion set for each PRACH configuration is TDMed and is composed of QCLed ROs on the same SSB beam and can be sequentially determined or ordered (e.g., like legacy) (1804). On the other hand, when PRACH repetition is performed considering multiple PRACH configurations, among the ROs of the multiple PRACH configurations, PRACH occasions that are TDMed and have the same SSB beam can be composed into one PRACH set and can be sequentially reindexed (1804).

[0287] FIG. 19 is a diagram illustrating an example of a PRACH repetition operation of a base station according to one embodiment of the present disclosure.

[0288] Referring to FIG. 19, the base station can set two different PRACH configurations to the terminal through upper layer signaling. For example, the base station can set PRACH occasion#0 (1901) with a relatively long period and PRACH occasion#1 (1902) with a relatively short period for applying PRACH adaptation. At this time, depending on the two PRACH configuration settings, the PRACH occasions can overlap in the time domain, the frequency domain, each of the time / frequency domains, or both domains, or can be TDM / FDM.

[0289] According to one embodiment, the base station may set configuration information for PRACH repetition (e.g., thresholds for each PRACH repetition number) to the terminal. At this time, if the base station sets the PRACH repetition considering the two PRACH configurations set in FIG. 19, the terminal may determine a set of PRACH occasions for PRACH repetition by using TDMed ROs in the same frequency band. The terminal may use the configuration information of the PRACH repetition selected for PRACH transmission according to the PRACH repetition configuration associated with the closest (earliest) PRACH occasion where the terminal can transmit PRACH, or may determine the configuration information based on the maximum transmittable number of PRACH repetitions of different PRACH configurations corresponding to the two PRACH occasions.

[0290] According to one embodiment, the value of the number of PRACH repetitions for the actual PRACH repetition may be determined by the terminal as the number of PRACH repetitions determined by comparing the DL pathloss RSRP measured via SSB with a threshold.

[0291] In one embodiment, the base station may configure common PRACH repetition information according to the capabilities of the terminal. For example, for a terminal without PRACH adaptation capability, the PRACH repetition may not be configured or a threshold may be set to allow a smaller number of PRACH repetitions. Conversely, for a terminal with PRACH adaptation capability, the threshold may be set to allow a larger number of PRACH repetitions.

[0292] Additionally, terminals that always support PRACH adaptation may be restricted to use PRACH occasion #1. In one embodiment, the above operation may be applied to manage the contention ratio and interference during PRACH transmission at the discretion of the base station.

[0293] Referring to FIG. 19, UE#0 can receive two different PRACH configurations from the base station. Then, UE#0 can determine the fastest PRACH occasion#0 (1901) for PRACH transmission and determine PRACH repetition setting information of the corresponding PRACH configuration. Then, based on the received SSB, DL pathloss RSRP can be compared with the configured threshold to determine the PRACH repetition. Then, in the corresponding PRACH occasion#0, an RO set for PRACH repetition can be determined and PRACH repetition can be transmitted (1903). At this time, if RO#0 and RO#2 in the corresponding RO set (1903) are used for PRACH repetition, RO#0 RO#2 in order of #1 #2 can be indexed. Similarly, terminal UE#1 can select the fastest PRACH occasion#1 (1902) and then perform the PRACH repetition operation in the RO set (1904) as described above.

[0294] Hereinafter, PRACH configuration methods for supporting the above operations are described. A base station can set configuration information for one or more PRACH repetitions to a terminal through higher layer signaling (e.g., system information block or RRC signaling). For example, information related to PRACH repetition configurations as exemplified in Table 14 below can be additionally set. At this time, the following information can be set for each of multiple PRACH configurations, or the following configuration information can be set for common use. In addition, at least one of the configuration information for PRACH repetition described in Table 14 can be set. Alternatively, at least one of the configuration information in Table 14 can be set for Rel-19. In addition, a common PRACH repetition configuration can be included and set in BWP-UplinkCommon (or similar information).

[0295]

[0296] FIG. 20 is a diagram illustrating an example of a PRACH adaptation operation of a base station and a terminal according to one embodiment of the present disclosure.

[0297] Specifically, FIG. 20 is a flowchart illustrating the operation of a terminal applying an energy-saving method for a wireless communication system according to one embodiment of the present disclosure. Various modifications may be made to the method illustrated in the flowchart of FIG. 20 . For example, although illustrated as a series of steps, the various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other examples, individual steps may be omitted or replaced with other steps.

[0298] Based on FIG. 20, the operation of the terminal for PRACH repetition during the PRACH adaptation operation for energy saving is described.

[0299] Referring to FIG. 20, in step 2001, the terminal may receive two different PRACH configuration information (or setting information) from the base station through upper layer signaling (e.g. RRC or SIB).

[0300] In step 2002, the terminal can receive threshold setting information (such as threshold information) for determining PRACH repetition from the base station through upper layer signaling (e.g. RRC or SIB).

[0301] In step 2003, the terminal can determine the PRACH repetition by comparing the RSRP of the DL pathloss reference of the received SSB with the threshold.

[0302] In step 2004, the terminal can determine a valid PRACH occasion based on the above settings and determine an RO set for PRACH repetition.

[0303] In step 2005, the terminal can transmit PRACH repetitions in the determined RO resources.

[0304] Specific details of terminal operation according to one embodiment of the present disclosure may be referred to the description of various embodiments of the present disclosure.

[0305] FIG. 21 is a diagram illustrating an example of a PRACH adaptation operation of a base station and a terminal according to one embodiment of the present disclosure.

[0306] Specifically, FIG. 21 is a flowchart of the operation of a base station applying an energy saving method of a wireless communication system according to one embodiment of the present disclosure.

[0307] Various modifications can be made to the method illustrated in the flowchart of Figure 21. For example, although depicted as a series of steps, the various steps in each diagram 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.

[0308] Referring to FIG. 21, in step 2101, the base station may transmit two different PRACH configuration information (or setting information) to the terminal through upper layer signaling (e.g. RRC or SIB).

[0309] In step 2102, the base station may transmit threshold setting information (e.g., threshold information) for determining PRACH repetition through higher layer signaling (e.g., RRC or SIB).

[0310] In step 2103, the base station can determine a valid PRACH occasion based on the above settings and determine an RO set for PRACH repetition.

[0311] In step 2104, the base station can receive PRACH repetitions from the determined RO resources.

[0312] Specific details of the base station operation according to one embodiment of the present disclosure may be referred to the description of various embodiments of the present disclosure.

[0313] 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.

[0314] FIG. 22 is a block diagram of a terminal according to one embodiment of the present disclosure.

[0315] Referring to FIG. 22, a terminal (2200) may include a transceiver (2201), a control unit (e.g., a processor) (2202), and a storage unit (e.g., a memory) (2203). The transceiver (2201), the control unit (2202), and the storage unit (2203) of the terminal (2200) 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 (2200) are not limited to the illustrated example. According to other embodiments, the terminal (2200) may include more or fewer components than the components described above. In addition, in certain cases, the transceiver (2201), the control unit (2202), and the storage unit (2203) may be implemented in the form of a single chip.

[0316] The transceiver (2201) may, according to one embodiment, be composed of a transmitter and a receiver. The transceiver (2201) may transmit and receive signals with a base station. The signals may include control information and data. The transceiver (2201) 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-downconverts the received signal. The transceiver (2201) may receive a signal through a wireless channel and output the signal to the control unit (2202), and may transmit the signal output from the control unit (2202) through the wireless channel.

[0317] The control unit (2202) may control a series of procedures that the terminal (2200) may perform according to the embodiments of the present disclosure described above. For example, the control unit (2202) 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 (2202) may include at least one processor. For example, the control unit (2202) 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).

[0318] The storage unit (2203) can store control information (e.g., information related to channel estimation using DMRSs transmitted on PUSCH included in a signal acquired from the terminal (2200)) or data, and can have an area for storing data required for controlling the control unit (2202) and data generated during control by the control unit (2202).

[0319] Figure 23 is a block diagram of a base station according to one embodiment.

[0320] Referring to FIG. 23, a base station (2300) may include a transceiver (2301), a control unit (e.g., a processor) (2302), and a storage unit (e.g., a memory) (2303). The transceiver (2301), the control unit (2302), and the storage unit (2303) of the base station (2300) 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 (2300) are not limited to the illustrated example. According to other embodiments, the base station (2300) may include more or fewer components than the components described above. In addition, in certain cases, the transceiver (2301), the control unit (2302), and the storage unit (2303) may be implemented in the form of a single chip.

[0321] The transceiver (2301) may, according to one embodiment, be composed of a transmitter and a receiver. The transceiver (2301) may transmit and receive signals with a terminal. The signals may include control information and data. The transceiver (2301) 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 (2301) may receive a signal through a wireless channel and output the signal to the control unit (2302), and may transmit the signal output from the control unit (2302) through the wireless channel.

[0322] The control unit (2302) may control a series of procedures so that the base station (2300) can operate according to the embodiments of the present disclosure described above. For example, the control unit (2302) 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 (2302) may include at least one processor. For example, the control unit (2302) 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).

[0323] The storage unit (2303) can store control information (e.g., information related to channel estimation generated using DMRSs transmitted on a PUSCH determined by the base station (2300), data, control information received from a terminal, or data, and can have an area for storing data required for controlling the control unit (2302) and data generated during control by the control unit (2302).

[0324] 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.

[0325] 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 wireless communication system, A step of receiving configuration information for a first RO (physical random access channel occasion) and configuration information for a second RO from a base station; A step of determining PRACH (physical random access channel) repetition based on SSB (synchronization signal block); a step of determining a RO set for the above PRACH repetition; and A method comprising the step of performing the PRACH repeated transmission based on the determined RO set.

2. In paragraph 1, A method characterized in that the RO set includes the first RO and does not include the second RO.

3. In paragraph 1, A method characterized in that the RO set includes at least one of the first RO and the second RO.

4. In paragraph 1, A step of receiving information related to a threshold for determining the PRACH repetition from the base station; and A step of determining PRACH repetition based on information related to the above threshold and the above SSB, The above first RO is a legacy RO, the above second RO is an additional RO, and A method characterized in that the above additional RO is related to a terminal supporting NES (network energy savings).

5. In a method performed by a base station of a wireless communication system, A step of transmitting, to the terminal, configuration information for a first RO (physical random access channel occasion) and configuration information for a second RO; and A step of receiving, from the terminal, the PRACH (physical random access channel) repetition transmission of the terminal based on an RO set for PRACH repetition, A method characterized in that the above PRACH repetition is determined based on a synchronization signal block (SSB).

6. In paragraph 5, A method characterized in that the RO set includes the first RO and does not include the second RO.

7. In paragraph 5, A step of transmitting, to the terminal, information related to a threshold for determining the PRACH repetition, The above RO set includes at least one of the first RO and the second RO, The above first RO is a legacy RO, the above second RO is an additional RO, and A method characterized in that the above additional RO is related to a terminal supporting NES (network energy savings).

8. In the terminal of a wireless communication system, At least one transceiver; At least one processor communicatively connected to said at least one transceiver; and A terminal including a memory that is communicatively connected to at least one processor and that is executable individually or in any combination by the at least one processor, and that stores instructions that cause the terminal to receive, from a base station, configuration information for a first RO (physical random access channel occasion) and configuration information for a second RO, determine PRACH (physical random access channel) repetition based on a synchronization signal block (SSB), determine a RO set for the PRACH repetition, and perform the PRACH repetition transmission based on the determined RO set.

9. In paragraph 8, A terminal characterized in that the RO set includes the first RO and does not include the second RO.

10. In paragraph 8, A terminal characterized in that the RO set includes at least one of the first RO and the second RO.

11. In paragraph 8, The above command causes the terminal to receive, from the base station, information related to a threshold for determining the PRACH repetition, and further determine the PRACH repetition based on the information related to the threshold and the SSB. The above first RO is a legacy RO, the above second RO is an additional RO, and The above additional RO is a terminal characterized in that it is related to a terminal that supports NES (network energy savings).

12. In a base station of a wireless communication system, At least one transceiver; At least one processor communicatively connected to said at least one transceiver; and A memory communicatively connected to at least one processor and executable by the at least one processor individually or in any combination, wherein the memory stores instructions that cause the base station to transmit to the terminal, configuration information for a first RO (physical random access channel occasion) and configuration information for a second RO, and receive, from the terminal, a PRACH repetition transmission of the terminal based on an RO set for PRACH repetition, A base station, characterized in that the above PRACH repetition is determined based on a synchronization signal block (SSB).

13. In paragraph 12, A base station, characterized in that the RO set includes the first RO and does not include the second RO.

14. In paragraph 12, A base station, characterized in that the RO set includes at least one of the first RO and the second RO.

15. In paragraph 12, The above command further causes the base station to transmit to the terminal information related to a threshold for determining the PRACH repetition, The above first RO is a legacy RO, the above second RO is an additional RO, and A base station characterized in that the above additional RO is related to a terminal supporting NES (network energy savings).

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