Random access method and device in prach adaptation for energy saving of base station in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. The present disclosure provides a PRACH adaptation method for energy saving of a base station, and a device for performing the method.

Description

Random access method and device for PRACH adjustment for base station energy saving in wireless communication system

[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] The present disclosure discloses a method and device for reducing energy consumption in a communication system. In particular, the present disclosure discloses a method and device for performing PRACH adaptation during random access.

[0010] According to one embodiment of the present disclosure, a method performed by a terminal of a communication system comprises the steps of: obtaining additional PRACH (physical random access channel) configuration information; transmitting a PRACH preamble to a base station at a PRACH occasion based on the additional PRACH configuration information; identifying a RA-RNTI (random access - radio network temporary identifier) ​​based on the PRACH occasion; receiving a PDCCH (physical downlink control channel) from the base station based on the RA-RNTI, wherein the PDCCH schedules a downlink data channel; and receiving a RAR (random access response) on the downlink data channel from the base station, wherein the RA-RNTI is identified based on a frequency domain index of the PRACH occasion, and a minimum value of the frequency domain index is the number of FDMed (frequency division multiplexed) PRACH occasions included in conventional PRACH configuration information.

[0011] In addition, a method performed by a base station of a communication system comprises the steps of: obtaining additional PRACH (physical random access channel) configuration information; receiving a PRACH preamble from the terminal at a PRACH occasion related to the additional PRACH configuration information; identifying a RA-RNTI (random access - radio network temporary identifier) ​​based on the PRACH occasion; transmitting a PDCCH (physical downlink control channel) to the terminal based on the RA-RNTI, wherein the PDCCH schedules a downlink data channel; and transmitting a RAR (random access response) to the terminal on the downlink data channel, wherein the RA-RNTI is identified based on a frequency domain index of the PRACH occasion, and a minimum value of the frequency domain index is the number of FDMed (frequency division multiplexed) PRACH occasions included in conventional PRACH configuration information.

[0012] Also, in a terminal of a communication system, at least one transceiver; at least one processor communicatively connected to the at least one transceiver; and a memory communicatively connected to the at least one processor and executable individually or in any combination of the at least one processor, the memory storing instructions that cause the terminal to: obtain additional PRACH (physical random access channel) configuration information, transmit a PRACH preamble to a base station at a PRACH occasion based on the additional PRACH configuration information, confirm a RA-RNTI (random access - radio network temporary identifier) ​​based on the PRACH occasion, receive a PDCCH (physical downlink control channel) from the base station based on the RA-RNTI, the PDCCH schedules a downlink data channel, and receive a RAR (random access response) on the downlink data channel from the base station; , and the RA-RNTI is identified based on a frequency domain index of the PRACH occasion, and the minimum value of the frequency domain index is the number of FDMed (frequency division multiplexed) PRACH occasions included in conventional PRACH configuration information.

[0013] Also, in a base station of a communication system, at least one transceiver; at least one processor communicatively connected to the at least one transceiver; and a memory communicatively connected to the at least one processor and executable individually or in any combination of the at least one processor, the memory storing instructions that cause the base station to: obtain additional PRACH (physical random access channel) configuration information, receive a PRACH preamble from the terminal at a PRACH occasion related to the additional PRACH configuration information, confirm a RA-RNTI (random access - radio network temporary identifier) ​​based on the PRACH occasion, transmit a PDCCH (physical downlink control channel) to the terminal based on the RA-RNTI, the PDCCH schedules a downlink data channel, and transmit a RAR (random access response) on the downlink data channel to the terminal; , and the RA-RNTI is identified based on a frequency domain index of the PRACH occasion, and the minimum value of the frequency domain index is the number of FDMed (frequency division multiplexed) PRACH occasions included in conventional PRACH configuration information.

[0014] 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.

[0015] 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.

[0016] 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.

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

[0018] FIG. 2 is a diagram illustrating a slot structure considered in a wireless communication system according to one embodiment of the present disclosure.

[0019] FIG. 3 is a diagram illustrating an example of a time domain mapping structure and beam sweeping operation of a synchronization signal according to one embodiment of the present disclosure.

[0020] FIG. 4 is a diagram illustrating a synchronization signal block considered in a wireless communication system according to one embodiment of the present disclosure.

[0021] FIG. 5 is a diagram illustrating 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.

[0022] FIG. 6 is a diagram illustrating 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.

[0023] 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.

[0024] FIG. 8 is a diagram illustrating a method for resetting SSB transmission through dynamic signaling in a wireless communication system according to one embodiment of the present disclosure.

[0025] FIG. 9 is a diagram illustrating an example of a PRACH adaptation operation of a base station according to one embodiment of the present disclosure.

[0026] FIG. 10 is a diagram illustrating an example of a PRACH adaptation operation of a base station according to one embodiment of the present disclosure.

[0027] FIG. 11 is a diagram illustrating an example of a PRACH adaptation operation of a base station according to one embodiment of the present disclosure.

[0028] FIG. 12 is a diagram illustrating another example of a PRACH adaptation operation of a base station according to an embodiment of the present disclosure.

[0029] FIG. 13 is a flowchart of the operation of a terminal to which an energy saving method of a wireless communication system according to one embodiment of the present disclosure is applied.

[0030] FIG. 14 is a flowchart of the operation of a base station to which an energy saving method of a wireless communication system according to one embodiment of the present disclosure is applied.

[0031] FIG. 15 is a block diagram of a terminal according to one embodiment of the present disclosure.

[0032] FIG. 16 is a block diagram of a base station according to one embodiment of the present disclosure.

[0033] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0034] 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.

[0035] 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.

[0036] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments 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.

[0037] 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.

[0038] Furthermore, while the LTE or LTE-A system may be described below as an example, embodiments of the present disclosure may also be applied to other communication systems with similar technical backgrounds or channel types. For example, this may include the fifth-generation mobile communication technology (5G, new radio, NR) developed after LTE-A, and the term "5G" below may also encompass existing LTE, LTE-A, and other similar services. Furthermore, the present disclosure may be applied to other communication systems with some modifications within the scope of the present disclosure, as determined by a person with skilled technical knowledge.

[0039] 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).

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] In the LTE system, which is a representative example of a broadband wireless communication system, the downlink (DL) uses the orthogonal frequency division multiplexing (OFDM) method, and the uplink (UL) uses 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.

[0045] 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).

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] FIG. 1 is a diagram illustrating a basic structure of a time-frequency domain, which is a wireless resource domain, in a wireless communication system according to one embodiment of the present disclosure.

[0052] In Fig. 1, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The basic unit of resources in the time and frequency domains is a resource element (RE, 101), which can be defined as one OFDM symbol (or DFT-s-OFDM (discrete Fourier transform spread OFDM) symbol, 102) in the time axis and one subcarrier (subcarrier, 103) in the frequency axis. In the frequency domain, the number of subcarriers per resource block (RB) is represented by (For example, 12) consecutive REs can form one resource block (RB, 104). In addition, the number of symbols per subframe according to the setting value μ for the subcarrier spacing in the time domain is indicated. A number of consecutive OFDM symbols can constitute one subframe (subframe, 110).

[0053] FIG. 2 is a diagram illustrating a slot structure considered in a wireless communication system according to one embodiment of the present disclosure.

[0054] FIG. 2 illustrates an example of a slot structure including a frame (frame, 200), a subframe (201), and slots (slots, 202, 203). One frame (200) can be defined as 10 ms. One subframe (201) can be defined as 1 ms, and therefore 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).

[0055] 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, the number of slots per subframe depends on the setting value μ for the subcarrier spacing. may vary, and accordingly the number of slots per frame can vary. For example, depending on the subcarrier spacing setting μ and can be defined as shown in Table 1 below.

[0056] μ 014101114202214404314808414160165143203261464064

[0057] 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).

[0058] In the initial access phase where a terminal connects to the system, the terminal can first acquire downlink time and frequency domain synchronization from a synchronization signal through cell search and acquire 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 physical broadcast channel (PBCH) that transmits a master information block (MIB) from a base station. Based on this information, the terminal can perform decoding on a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) to acquire 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.

[0059] 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.

[0060] FIG. 3 is a diagram illustrating an example of a time domain mapping structure and beam sweeping operation of a synchronization signal according to one embodiment of the present disclosure.

[0061] For illustrative purposes, the following components can be defined:

[0062] - PSS: A signal that serves as a reference for DL ​​time / frequency synchronization and provides some cell ID information.

[0063] - SSS: It serves as a reference signal 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.

[0064] - PBCH: Provides MIB, 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 transmitting system information, and SFN (system frame number), which is a frame-unit index that serves as a timing reference.

[0065] - SS / PBCH block: An SS / PBCH block consists of N OFDM symbols and is a combination of PSS, SSS, PBCH, etc. In a system where beam sweeping technology is applied, the SS / PBCH block is the minimum unit to which beam sweeping is applied. In a 5G system, N can be 4. The base station can transmit up to L SS / PBCH blocks, and the L SS / PBCH blocks are mapped within a half frame (0.5 ms). In addition, the L SS / PBCH blocks are periodically repeated in units of a predetermined period P. The period P can be notified to the terminal by the base station through signaling. If there is no separate signaling for the period P, the terminal applies a pre-agreed default value.

[0066] 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.

[0067] 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.

[0068] Below, the cell initial access operation procedure of a 5G wireless communication system will be described in more detail with reference to drawings.

[0069] 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.

[0070] FIG. 4 is a diagram illustrating a synchronization signal block considered in a wireless communication system according to one embodiment of the present disclosure.

[0071] Referring to FIG. 4, the synchronization signal block (SS block, 400) may include a PSS (401), an SSS (403), and a BCH (Physical Broadcast Channel) (402).

[0072] 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 × 3 =) 1008 cell IDs by detecting the PSS (401) and the SSS (403) and combining them. This can be expressed by the following mathematical expression 1.

[0073] [Mathematical Formula 1]

[0074]

[0075] 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.

[0076] PBCH (402) can be transmitted in resources including 6 RBs (407, 408) on both sides, excluding 12 RBs (405) in the middle, while SSS (403) is transmitted in 24 RBs (406) in the frequency axis and in the 2nd to 4th OFDM symbols of the SS block in the time axis. PBCH (402) can include a PBCH payload and a PBCH DMRS (demodulation reference signal), and various system information called MIB can be transmitted in the PBCH payload. For example, MIB can include information as shown in Table 2 below.

[0077] 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))}

[0078] - 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 the PBCH. In one embodiment, in a frequency band below 6 GHz, 3 bits obtained through decoding the PBCH DMRS indicate the synchronization signal block index, and in a frequency band above 6 GHz, a total of 6 bits, including 3 bits obtained through decoding the PBCH DMRS and 3 bits obtained through decoding the PBCH included in the PBCH payload, can indicate the synchronization signal block index including the PBCH.

[0079] - PDCCH configuration information: The subcarrier spacing of the common downlink control channel can be indicated through 1 bit (subCarrierSpacingCommon) in the MIB, and the time-frequency resource configuration information of the CORESET (control resource set) and search space (SS) can be indicated through 8 bits (pdcch-ConfigSIB1).

[0080] - SFN: Within the MIB, 6 bits (systemFrameNumber) can be used to indicate a portion of the SFN. The 4 least significant bits (LSBs) of the SFN are included in the PBCH payload, so the terminal can indirectly obtain them through PBCH decoding.

[0081] - 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.

[0082] 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.

[0083] 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.

[0084] FIG. 5 is a diagram illustrating 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.

[0085] Referring to FIG. 5, in a 5G communication system, in a frequency band below 6 GHz (or FR1 (frequency range 1), for example, 410 MHz-7125 MHz), a 15 kHz subcarrier spacing (520) and a 30 kHz subcarrier spacing (530, 540) may be used for transmission of a synchronization signal block. In the 15 kHz subcarrier spacing (520), there may be one transmission case (e.g., case #1 (501)) for the synchronization signal block, and in the 30 kHz subcarrier spacing (530, 540), there may be two transmission cases (e.g., case #2 (502) and case #3 (503)) for the synchronization signal block.

[0086] In case #1 (501) at a 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. 5, 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.

[0087] 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.

[0088] In case #2 (502) at the subcarrier spacing of 30 kHz (530) in FIG. 5, a maximum of two synchronization signal blocks can be transmitted within 0.5 ms (505) (or 1 slot length when 1 slot consists of 14 OFDM symbols), and accordingly, a maximum of four synchronization signal blocks can be transmitted within 1 ms (or 2 slot lengths when 1 slot consists of 14 OFDM symbols). In the example of FIG. 5, 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.

[0089] 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.

[0090] In case #3 (503) at subcarrier spacing of 30 kHz (540) in FIG. 5, a maximum of two synchronization signal blocks can be transmitted within 0.5 ms (506) (or 1 slot length when 1 slot consists of 14 OFDM symbols), and accordingly, a maximum of four synchronization signal blocks can be transmitted within 1 ms (or 2 slot lengths when 1 slot consists of 14 OFDM symbols). In the example of FIG. 5, 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.

[0091] 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.

[0092] FIG. 6 is a diagram illustrating 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.

[0093] Referring to FIG. 6, in a wireless communication system, in a frequency band of 6 GHz or higher (or FR2, for example, 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.

[0094] 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.

[0095] 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.

[0096] 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).

[0097] 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.

[0098] 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.

[0099] 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.

[0100] Referring to FIG. 7, in a 5G communication system, a synchronization signal block may be transmitted periodically in units of, for example, a time interval of 5 ms (710, corresponding to 5 subframes or half frames).

[0101] 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.

[0102] In case #1 (720) of FIG. 7 and case #1 (501) of FIG. 5 with a subcarrier spacing of 15 kHz consisting of one slot, 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 a frequency band exceeding 3 GHz and below 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 (730) or case #3 (740) of FIG. 7 and case #2 (502) or case #3 (503) of FIG. 5 with a subcarrier spacing of 30 kHz consisting of two slots, synchronization signal blocks can be mapped starting from the first slot in a frequency band below 3 GHz, 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.

[0103] Subcarrier spacings of 120 kHz and 240 kHz can be used in frequencies exceeding 6 GHz. In case #4 (750) of Fig. 7 and case #4 (610) with subcarrier spacing of 120 kHz consisting of two slots of Fig. 6, synchronization signal blocks can be mapped starting from slots 1, 3, 5, 7, 11, 13, 15, 17, 21, 23, 25, 27, 31, 33, 35, and 37 in the frequency band exceeding 6 GHz, so that up to 64 (751) can be transmitted. In case #5 (760) of Fig. 7 and case #5 (620) of Fig. 6 with a subcarrier spacing of 240 kHz consisting of 4 slots, 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.

[0104] 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.

[0105] 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 a random access procedure in a 5G system.

[0106] - 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.

[0107] Below, a method for setting a measurement time for RRM (radio resource management) based on a synchronization signal block of a 5G wireless communication system is described.

[0108] The terminal receives MeasObjectNR of MeasObjectToAddModList as a setting for SSB-based intra / inter-frequency measurements and CSI-RS (channel state information-reference signal)-based intra / inter-frequency measurements through upper layer signaling. For example, MeasObjectNR can be configured as shown in Table 4 below.

[0109] MeasObjectNR ::= SEQUENCE {ssbFrequency ARFCN-ValueNR OPTIONAL, -- Cond SSBorAssociatedSSBssbSubcarrierSpacing SubcarrierSpacing OPTIONAL, -- Cond SSBorAssociatedSSBsmtc1 SSB-MTC OPTIONAL, -- Cond SSBorAssociatedSSBsmtc2 SSB-MTC2 OPTIONAL, -- Cond IntraFreqConnectedrefFreqCSI-RS ARFCN-ValueNR OPTIONAL, -- Cond CSI-RSreferenceSignalConfig ReferenceSignalConfig,absThreshSS-BlocksConsolidation ThresholdNR OPTIONAL, -- Need RabsThreshCSI-RS-Consolidation ThresholdNR OPTIONAL, -- Need RnrofSS-BlocksToAverage INTEGER (2..maxNrofSS-BlocksToAverage) OPTIONAL, -- Need RnrofCSI-RS-ResourcesToAverage INTEGER (2..maxNrofCSI-RS-ResourcesToAverage) OPTIONAL, -- Need RquantityConfigIndex INTEGER (1..maxNrofQuantityConfig),offsetMO Q-OffsetRangeList,cellsToRemoveList PCI-List OPTIONAL, -- Need NcellsToAddModList CellsToAddModList OPTIONAL, -- Need NblackCellsToRemoveList PCI-RangeIndexList OPTIONAL, -- Need NblackCellsToAddModList SEQUENCE (SIZE (1..maxNrofPCI-Ranges)) OF PCI-RangeElement OPTIONAL, -- Need NwhiteCellsToRemoveList PCI-RangeIndexList OPTIONAL, -- Need NwhiteCellsToAddModList SEQUENCE (SIZE (1..maxNrofPCI-Ranges)) OF PCI-RangeElement OPTIONAL, -- Need N...,[[freqBandIndicatorNR FreqBandIndicatorNR OPTIONAL, -- Need RmeasCycleSCell ENUMERATED {sf160, sf256, sf320, sf512, sf640, sf1024, sf1280} OPTIONAL -- Need R]],[[smtc3list-r16 SSB-MTC3List-r16 OPTIONAL, -- Need Rrmtc-Config-r16 SetupRelease {RMTC-Config-r16} OPTIONAL, -- Need Mt312-r16 SetupRelease { T312-r16} OPTIONAL -- Need M]]}.

[0110] The terms in Table 4 can perform the following functions, but are not limited thereto.

[0111] -ssbFrequency:You can set the frequency of the synchronization signal associated with MeasObjectNR.

[0112] -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.

[0113] -smtc1: Indicates SMTC (SS / PBCH block measurement timing configuration), which sets the primary measurement timing configuration and allows you to set the timing offset and duration for SSB.

[0114] -smtc2:pci-List allows you to set the secondary measurement timing configuration for SSBs associated with MeasObjectNRs with PCIs listed in -smtc2:pci-List.

[0115] 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.

[0116] For SSB measurement, the terminal can set the first 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 in the subframe of the SFN and SpCell that satisfy the conditions in Table 5 below.

[0117] SFN modT= (FLOOR (Offset / 10));if thePeriodicityis larger thansf5:subframe =Offsetmod 10;else:subframe =Offsetor (Offset+5);withT= CEIL(Periodicity / 10).

[0118] 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) for the same frequency (e.g., a frequency for intra-frequency cell reselection) or 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.

[0119] Below, we describe a time domain resource allocation (TDRA) method for data channels in a 5G communication system. A base station can configure a time domain resource allocation information table for a downlink data channel (PDSCH) and an uplink data channel (physical uplink shared channel, PUSCH) to a terminal through higher layer signaling (e.g., RRC signaling).

[0120] The base station may set a table with a maximum of maxNrofDL-Allocations=17 entries for PDSCH, and may set a table with a maximum of maxNrofUL-Allocations=17 entries for PUSCH. The time domain resource allocation information may include, for example, at least one of PDCCH-to-PDSCH slot timing (corresponding to a slot-unit time interval between a time point when a PDCCH is received and a time point when a PDSCH scheduled by the received PDCCH is transmitted, denoted as K0) or PDCCH-to-PUSCH slot timing (corresponding to a slot-unit time interval between a time point when a PDCCH is received and a time point when a PUSCH scheduled by the received PDCCH is transmitted, denoted as K2), information on the position and length of a start symbol on which a PDSCH or PUSCH is scheduled within a slot, and a mapping type of a PDSCH or PUSCH.

[0121] In one embodiment, time domain resource allocation information for PDSCH can be set to a terminal through RRC signaling as shown in Table 6 below.

[0122] PDSCH-TimeDomainResourceAllocationListinformation elementPDSCH-TimeDomainResourceAllocationList ::= SEQUENCE (SIZE(1..maxNrofDL-Allocations)) OF PDSCH-TimeDomainResourceAllocationPDSCH-TimeDomainResourceAllocation ::= SEQUENCE {k0 INTEGER(0..32) OPTIONAL, -- Need SmappingType ENUMERATED {typeA, typeB},startSymbolAndLength INTEGER (0..127)repetitionNumber ENUMERATED {n2, n3, n4, n5, n6, n7, n8, n16} OPTIONAL, -- Cond Formats1-0and1-1}

[0123] 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 may represent the number of PDSCH transmission occasions according to the slot-based repetition method. In one embodiment, time domain resource allocation information for PUSCH may be set to the terminal through RRC signaling as shown in Table 7 below.

[0124] PUSCH-TimeDomainResourceAllocationinformation elementPUSCH-TimeDomainResourceAllocationList ::= SEQUENCE (SIZE(1..maxNrofUL-Allocations)) OF PUSCH-TimeDomainResourceAllocationPUSCH-TimeDomainResourceAllocation ::= SEQUENCE {k2 INTEGER(0..32) OPTIONAL, -- Need SmappingType ENUMERATED {typeA, typeB},startSymbolAndLength INTEGER (0..127)}PUSCH-Allocation-r16 ::= SEQUENCE {mappingType-r16 ENUMERATED {typeA, typeB} OPTIONAL, -- Cond NotFormat01-02-Or-TypeAstartSymbolAndLength-r16 INTEGER (0..127) OPTIONAL, -- Cond NotFormat01-02-Or-TypeAstartSymbol-r16 INTEGER (0..13) OPTIONAL, -- Cond RepTypeBlength-r16 INTEGER (1..14) OPTIONAL, -- Cond RepTypeBnumberOfRepetitions-r16 ENUMERATED {n1, n2, n3, n4, n7, n8, n12, n16} OPTIONAL, -- Cond Format01-02...}

[0125] 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. The base station may indicate at least one entry of the table for time domain resource allocation information to the terminal through L1 signaling (e.g., downlink control information (DCI)) (e.g., by a 'time domain resource allocation' field in the DCI). The terminal may acquire time domain resource allocation information for the PDSCH or PUSCH based on the DCI received from the base station.

[0126] Below, we describe a method for reducing SSB density through dynamic signaling to save base station energy in 5G systems.

[0127] FIG. 8 is a diagram illustrating a method for resetting SSB transmission through dynamic signaling in a wireless communication system according to one embodiment of the present disclosure.

[0128] Fig. 8 illustrates a method (801) for reconfiguring SSB transmission via bitmap-based group / cell common DCI. Referring to Fig. 8, a terminal can receive ssb-PositionsInBurst = '11110000' (802) from a base station through upper layer signaling (SIB1 or ServingCellConfigCommon). A maximum of two synchronization signal blocks at a subcarrier spacing of 30 kHz can be transmitted within 0.5 ms (or 1 slot length when 1 slot consists of 14 OFDM symbols), and thus, the terminal can receive 4 synchronization signal blocks within 1 ms (or 2 slot lengths when 1 slot consists of 14 OFDM symbols). At this time, the base station can reset the SSB transmission configuration information by broadcasting the bitmap '1010xxxx' (804) through the group / cell common DCI (803) having the nwes-RNTI (network energy saving-radio network temporary identifier, or es-RNTI) to reduce the density of SSB transmission for energy saving. At this time, the transmission of SS block#1 (805) and SS block#3 (806) can be canceled based on the bitmap (804) set by the group / cell common DCI.

[0129] In addition, the base station can reset the ssb-periodicity set through upper layer signaling via group / cell common DCI. In addition, timer information for indicating the application time of the group / cell common DCI can be additionally set, and SSB can be transmitted through the SSB transmission information reset to the 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. In this way, the setting can be changed from normal mode to energy saving mode through the timer, and the SSB configuration information can be reset accordingly. Alternatively, the base station can set the application time and period of the SSB configuration information reset through the 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 the group / cell common DCI is received to the moment the Offset is applied.

[0130] Below, we propose an operation to adjust (adapt) PRACH for energy saving of a base station in a 5G system.

[0131] FIG. 9 is a diagram illustrating an example of a PRACH adaptation operation of a base station according to one embodiment of the present disclosure.

[0132] The base station can set PRACH adaptation for energy saving. In this case, as an example of a PRACH adaptation method (case 1, 901), the base station can consider the overall mobility and number of terminals, and set an additional PRACH resource (or referred to as a PRACH occasion in the present invention) through an additional PRACH configuration or PRACH configuration index in addition to the PRACH resource through the existing SIB or PRACH configuration index, or change the PRACH resource (i.e., periodicity, time / frequency resources, etc.) through a method of additionally indicating the PRACH configuration or PRACH configuration index. The method of indicating the additional PRACH configuration index may be a higher-order signal such as an SIB, or may be indicated through RRC or DCI. Alternatively, the additional PRACH configuration index may be indicated through another signaling method depending on whether the terminal supporting the additional PRACH configuration index is in an RRC idle state or an RRC connected state. For example, in the case of an RRC idle terminal, it may be indicated through DCI for indicating system information such as SIB or paging, and in the case of an RRC connected terminal, it may be indicated through RRC or DCI.

[0133] More specifically, referring to Case 1 (901) of FIG. 9, the terminal can receive two PRACH occasions, PRACH occasion#0 (902) and PRACH occasion#1 (903), from the base station through upper layer signaling. At this time, PRACH occasion#0 (902) can be configured as a resource always used for PRACH transmission without considering PRACH adaptation. On the other hand, for energy saving of the base station, PRACH occasion#1 (903) can be used as an occasion to which PRACH adaptation can be applied.

[0134] For example, two PRACH occasions can be established through different upper layer signaling and can operate simultaneously. Afterwards, based on the established PRACH occasion#1(903), if the number of currently activated terminals or traffic requests is small, the base station can turn off PRACH occasion#1(903) and perform initial access and PRACH reception operations only through PRACH occasion#0(902) with a long period of 20 ms. The base station can transmit a signal to the terminal to turn off PRACH occasion#1(903). Based on the signal, the terminal can turn off (or deactivate) PRACH occasion#1(903) and transmit a PRACH preamble to the base station only through PRACH occasion#0(902) with a long period of 20 ms.

[0135] On the other hand, if the base station determines that the number of terminals camping at the base station has increased and there may be many PRACH collisions, the base station may turn on (or on, or activate) PRACH occasion#1(903) and perform initial access and PRACH reception operations based on a shorter period (for example, 10 ms) of PRACH occasion#1(903). The base station may transmit a signal to the terminal to turn on PRACH occasion#1(903). The terminal may turn on PRACH occasion#1(903) based on the signal and transmit a PRACH preamble to the base station through PRACH occasion#1(903). At this time, the base station may configure PRACH adaptation using higher layer signaling and L1 signaling, and in the case of PRACH occasion#1(903), the periodicity may be changed and operated according to the PRACH adaptation.

[0136] The above-described methods are not limited to what is described above, and can be extended to apply N PRACH occasion configurations and SSB patterns of various periodicities and ssb-positionInburst. For example, there are N PRACH occasion configurations between a base station and a terminal, and at least one PRACH occasion configuration among them can always be used for PRACH transmission regardless of the energy saving configuration or PRACH adaptation configuration of the base station. Other PRACH occasions are PRACH occasions to which PRACH adaptation can be applied, and the same or different periodicities and / or the same or different SSB patterns can be applied to each PRACH occasion. Through the above method, the base station can apply PRACH adaptation and obtain an energy saving effect, while ensuring contention performance during PRACH transmission for initial access of the terminal.

[0137] FIG. 10 is a diagram illustrating an example of a PRACH adaptation operation of a base station according to one embodiment of the present disclosure.

[0138] Referring to FIG. 10, the base station can configure two different PRACH configurations to the terminal via higher-layer signaling. More specifically, the base station can configure PRACH occasion#0 (1001) with a long period and PRACH occasion#1 (1002) with a short period for applying PRACH adaptation to the terminal. In this case, a valid PRACH occasion for PRACH transmission can be determined using one of the following methods.

[0139] [Method 1-1]

[0140] Method 1-1 proposes a PRACH transmission method in which the PRACH occasion and PRACH configuration are selected based on the fastest (or closest to the terminal) PRACH occasion.

[0141] The UE can determine the first configured PRACH occasion for PRACH transmission and perform the PRACH transmission operation based on the PRACH configuration that sets the corresponding PRACH occasion. More specifically, referring to FIG. 10, when UE#0 performs PRACH transmission, UE#0 can select RO#0 (1003) of the first configured (or closest) PRACH occasion #0 (1001) and perform the PRACH transmission operation through the PRACH occasions set to PRACH configuration#0 corresponding to RO#0 (1003) of the corresponding PRACH occasion #0 (1001) (1004). That is, UE#0 transmits the PRACH on the PRACH occasions set to PRACH configuration#0.

[0142] On the other hand, UE#1 can select RO#1 (1005) of PRACH occasion #1 (1002) as the first configured (or closest) PRACH occasion for PRACH transmission. Thereafter, UE#1 can perform PRACH transmission operation based on PRACH configuration#1 corresponding to RO#1 (1005) of PRACH occasion #1 (1002) (1006). That is, UE#1 transmits PRACH on PRACH occasions configured with PRACH configuration#1.

[0143] This method reduces complexity of the terminal by allowing the terminal to perform PRACH transmission operations based on a single PRACH configuration. Furthermore, the terminal can ensure delay performance by selecting the fastest PRACH occasion to perform PRACH transmission (i.e., PRACH transmission can be performed without delay).

[0144] [Method 1-2]

[0145] Method 1-2 proposes a PRACH transmission method that considers all PRACH occasions based on multiple configured PRACH configurations.

[0146] The UE can determine a valid occasion for PRACH transmission and transmit the PRACH by considering all of the multiple PRACH configurations (e.g., PRACH configuration #0 and PRACH configuration #1) set by the base station through upper layer signaling for PRACH transmission (1007). That is, UE#0 and UE#1 can perform PRACH transmission on PRACH occasions based on PRACH configuration #0 and PRACH occasions based on PRACH configuration #1. In this case, since the UE can perform PRACH transmission based on more PRACH occasions, the effect of improving competition between PRACH transmissions can be obtained.

[0147] As in the above methods, the base station can configure multiple PRACH configurations for PRACH adaptation and receive PRACHs from the terminal based on these configurations. At this time, the base station can perform at least one of selection, activation, or deactivation for some of the multiple PRACH configurations through upper layer signaling and L1 signaling, thereby indicating PRACH adaptation.

[0148] Below, we describe PRACH configuration methods to support the above operations. The base station can configure one or more PRACH configurations to the terminal through higher-layer signaling (e.g., SIB or RRC signaling). In this case, the base station can configure a PRACH occasion corresponding to the default operation using existing PRACH configuration information. PRACH adaptation may not be applied to the corresponding PRACH occasion.

[0149] A base station may configure additional multiple PRACH configurations for energy saving. More specifically, the base station may additionally configure PRACH configuration-related information as exemplified in Table 8 below. At this time, an additional PRACH configuration ID may be newly added for PRACH adaptation to distinguish between multiple PRACH configurations. The information in Table 8 below may correspond to a specific PRACH configuration ID. The information in Table 8 below is merely an example, and the contents of the present disclosure are not limited by the contents of Table 8.

[0150] RACH-ConfigCommon-r19 ::= SEQUENCE {rach-ConfigGeneric RACH-ConfigGeneric,totalNumberOfRA-Preambles INTEGER (1..63)ssb-perRACH-OccasionAndCB-PreamblesPerSSB CHOICE {oneEighth ENUMERATED {n4,n8,n12,n16,n20,n24,n28,n32,n36,n40,n44,n48,n52,n56,n60,n64},oneFourth ENUMERATED {n4,n8,n12,n16,n20,n24,n28,n32,n36,n40,n44,n48,n52,n56,n60,n64},oneHalf ENUMERATED {n4,n8,n12,n16,n20,n24,n28,n32,n36,n40,n44,n48,n52,n56,n60,n64},one ENUMERATED {n4,n8,n12,n16,n20,n24,n28,n32,n36,n40,n44,n48,n52,n56,n60,n64},two ENUMERATED {n4,n8,n12,n16,n20,n24,n28,n32},four INTEGER (1..16),eight INTEGER (1..8),sixteen INTEGER (1..4)}prach-RootSequenceIndex CHOICE {l839 INTEGER (0..837),l139 INTEGER (0..137)},msg1-SubcarrierSpacing SubcarrierSpacing...}RACH-ConfigDedicated-r19 ::= SEQUENCE {cfra CFRA OPTIONAL, -- Need Sra-Prioritization RA-Prioritization...,[[ra-PrioritizationTwoStep-r16 RA-Prioritizationcfra-TwoStep-r16 CFRA-TwoStep-r16]]}RACH-ConfigGeneric-r19 ::= SEQUENCE {prach-ConfigurationIndex INTEGER (0..255),msg1-FDM ENUMERATED {one, two, four, eight},msg1-FrequencyStart INTEGER (0..maxNrofPhysicalResourceBlocks-1),zeroCorrelationZoneConfig INTEGER(0..15),preambleReceivedTargetPower INTEGER (-202..-60),preambleTransMax ENUMERATED {n3, n4, n5, n6, n7, n8, n10, n20, n50, n100, n200},powerRampingStep ENUMERATED {dB0, dB2, dB4, dB6},ra-ResponseWindow ENUMERATED {sl1, sl2, sl4, sl8, sl10, sl20, sl40, sl80},...,[[prach-ConfigurationPeriodScaling-IAB-r16 ENUMERATED {scf1,scf2,scf4,scf8,scf16,scf32,scf64}prach-ConfigurationFrameOffset-IAB-r16 INTEGER (0..63)prach-ConfigurationSOffset-IAB-r16 INTEGER (0..39)ra-ResponseWindow-v1610 ENUMERATED { sl60, sl160}prach-ConfigurationIndex-v1610 INTEGER (256..262)]],[[ra-ResponseWindow-v1700 ENUMERATED {sl240, sl320, sl640, sl960, sl1280, sl1920, sl2560}]]}.

[0151] Thereafter, the base station can configure (or instruct) selection or activation or / and deactivation of one or more of the PRACH configurations through at least one of SIB update, RRC reconfiguration, MAC CE, cell-specific or group common DCI or UE-specific DCI. At this time, scheduling of the configuration information can be instructed by DCI transmitted through CORESET#0, and in the case of DCI used for PRACH adaptation, it can be transmitted by CRC scrambled with a new RNTI for NES. Considering the configuration information, some information included in the existing RRC message can be newly included in the Rel-19 configuration for PRACH adaptation. At this time, when multiple PRACH configurations are selected, activated, or configured for PRACH adaptation and PRACH transmission, the total number of PRACH preambles considered for PRACH transmission, the total number of PRACH occasions that can be FDMed (frequency division multiplexed), and the total number of PRACH resources may be limited so as not to exceed values ​​that can be configured through an existing PRACH configuration. For example, the number of PRACH preambles may be limited to min(63, sum(configured PRACH preambles)) so as not to exceed 63, and the maximum number of PRACH occasions that can be FDMed simultaneously may be limited to 8, such as min(8, sum(configured msg1-FDMs)). The above settings are one embodiment of the present disclosure and may be applied to all values ​​that can be configured through an existing PRACH configuration.Additionally, for a terminal with Rel-19 NES capability, the maximum value of at least one of the total number of PRACH preambles considered, the total number of PRACH occasions that can be FDMed, and the total number of PRACH resources may be changed. Additionally, an additional PRACH configuration to support two-step RA operation may be applied for PRACH adaptation.

[0152] FIG. 11 is a diagram illustrating an example of a PRACH adaptation operation of a base station according to one embodiment of the present disclosure.

[0153] Referring to FIG. 11, the base station can set two different PRACH configurations to the terminal through upper layer signaling. More specifically, the base station can set PRACH occasion#0 (1101) with a long period and PRACH occasion#1 (1102) with a short period for applying PRACH adaptation to the terminal. At this time, depending on the two PRACH configuration settings, the PRACH occasions may overlap at least partially in the time domain, the frequency domain, or the time and frequency domains. At this time, if the beams of the corresponding PRACH occasion and the QCLed SSB at the base station are different, the base station may support only a specific PRACH occasion or support multiple PRACH occasions depending on the capabilities of the terminal (e.g., the number of panels, whether mTRP operation is performed, or whether multi-beam operation is performed).

[0154] A UE may apply PRACH priority and / or dropping rules between two overlapping PRACH occasions for PRACH transmission. More specifically, the UE may receive from the base station a PRACH configuration #0 (1101) that does not apply PRACH adaptation and a NES PRACH configuration #1 (1102) that takes PRACH adaptation into account. At this time, RO#0 of PRACH configuration #0 (1101) and RO#0 of NES PRACH configuration #1 (1102) may overlap in the time domain. At this time, if the SSB mapped (QCLed) to the two ROs is the same, for example, SSB#0, the UE may determine that the UE can perform PRACH transmission through the two PRACH occasions and may determine the two PRACH occasions as valid occasions (1103). Thereafter, the UE may select RO#0 set as NES PRACH configuration #1 (1102) among the two overlapping ROs to transmit the PRACH. In this case, the terminal can avoid competition with terminals that do not support NES PRACH occasion and improve interference between them.

[0155] Alternatively, if the SSBs mapped (QCLed) to two overlapping ROs are the same, the UE may select an RO corresponding to the PRACH configuration of the previous PRACH transmission to transmit the PRACH if the retransmission is a retransmission considering ramping-up, etc. after performing a previous PRACH transmission. The RO configuration methods for the UE to perform the actual PRACH transmission may be indicated by the upper layer signaling and / or L1 signaling of the base station. The UE may select the RO to transmit the PRACH according to the indicated method. Alternatively, the base station may indicate the PRACH occasion to be used when PRACH occasions according to different PRACH configurations overlap, by the upper layer signaling and / or L1 signaling. The method for selecting between the overlapping valid ROs is not limited to the above-described content, and multiple PRACH transmissions using the two ROs may also be considered, taking into account the status of the UE (e.g., the amount of transmittable power).

[0156] Afterwards, the terminal can confirm that RO#1(1104) of PRACH configuration#0(1101) and RO#2(1105) of PRACH configuration#1(1104) overlap in the time domain and are mapped to different SSBs. In the case of Fig. 11, RO#1(1104) of PRACH configuration#0(1101) is mapped to SSB#1, and RO#2(1105) of PRACH configuration#1(1104) is mapped to SSB#2. At this time, the terminal can omit RO#2(1105) of NES PRACH configuration#1(1104) considering it as a low priority (or can ignore it, or can determine it as an invalid occasion). Therefore, the terminal can determine only RO#1(1104) of PRACH configuration#0(1101) as a valid occasion. Through this, the issue of terminals that do not support PRACH adaptation can be resolved by prioritizing PRACH occasions for PRACH transmission of terminals that do not support PRACH adaptation. In other words, the above method can avoid contention that may occur during PRACH transmission with terminals that do not support NES PRACH occasions, and can improve interference between them.

[0157] Alternatively, if the SSBs mapped to the two overlapping ROs are different and the UE must perform PRACH retransmission considering ramping up in the overlapping ROs RO#1 (1104) and RO#2 (1105), the UE may also check validation by considering the PRACH configuration of the previous transmission. That is, the UE may select an RO based on the PRACH configuration corresponding to the previous transmission and transmit the PRACH.

[0158] Through the above operation, the terminal can check the validity of the PRACH occasion and perform PRACH transmission on the confirmed RO among the valid ROs based on the previous PRACH transmission, the base station's configuration information, or the NES RO priority transmission method. For example, if multiple SSBs are mapped to overlapping ROs, the terminal can determine whether the two ROs are valid based on the SSB information received for PRACH transmission. For example, the two ROs can be determined as valid ROs only when some of the SSBs mapped to each of the two ROs overlap or all of the SSBs overlap equally.

[0159] After the valid PRACH occasion is determined, the terminal can perform SSB-to-RO mapping again using one of the following methods. Alternatively, SSB-to-RO mapping can be performed again before determining the valid PRACH occasion, and a valid PRACH occasion can be determined based on the re-performed SSB-to-RO mapping.

[0160] [Method 2-1]

[0161] The UE can determine a valid PRACH occasion according to a priority rule by considering independent continuous SSB-to-RO mapping for ROs set with different PRACH configurations. Thereafter, the UE can continuously apply SSB-to-mapping to valid PRACH occasions excluding PRACH occasions that are omitted as a result of the determination. In the example of Fig. 11, SSB#0 and SSB#1 are mapped to RO#0 and RO#1 of PRACH configuration #0 (1101), respectively, and SSB#0 to SSB#3 are mapped to RO#0 to RO#3 of NES PRACH configuration #1 (1102), respectively. At this time, RO#1 of PRACH configuration #0 (1101) and RO#2 of NES PRACH configuration #1 (1102) overlap in the time domain, and since the two overlapping ROs are mapped to different SSBs, RO#2 of NES PRACH configuration #1 (1102) is omitted. Therefore, the omitted RO#2 (1105) is excluded, and SSB#2 can be mapped to the subsequent NES RO#3 (1106). Through this, beam operation with the same PRACH performance can be supported by evenly distributing the number of connected ROs per SSB.

[0162] [Method 2-2]

[0163] The terminal independently applies consecutive SSB-to-RO mapping to ROs set with different PRACH configurations, and then a specific RO can be omitted according to a priority rule. At this time, the SSB-to-RO mapping applied for the initial priority rule can be applied as is. In the example of Fig. 11, SSB#0 and SSB#1 are mapped to RO#0 and RO#1 of PRACH configuration #0 (1101), respectively, and SSB#0 to SSB#3 are mapped to RO#0 to RO#3 of NES PRACH configuration #1 (1102), respectively. At this time, RO#1 of PRACH configuration #0 (1101) and RO#2 of NES PRACH configuration #1 (1102) overlap in the time domain, and since the two overlapping ROs are mapped to different SSBs, RO#2 of NES PRACH configuration #1 (1102) is omitted. Even so, the mapping between RO and SSB remains unchanged, and thus, the SSB mapped to RO#3 can become SSB#3 (1107). This method can reduce the complexity of the terminal.

[0164] [Method 2-3]

[0165] The terminal can determine whether there is an overlap between occasions of ROs set based on different PRACH configurations, and apply separate SSB-to-RO mapping to each RO for overlapping PRACH adaptation and each RO for non-overlapping PRACH adaptation. In the example of Fig. 11, RO#0 of PRACH configuration #0 (1101) overlaps with RO#0 of NES PRACH configuration #1 (1102) in the time domain, and RO#1 of PRACH configuration #0 (1101) overlaps with RO#2 of NES PRACH configuration #1 (1102) in the time domain. In this case, RO#0 and RO#2 of NES PRACH configuration #1 (1102) are overlapping ROs, and RO#1 and RO#3 are non-overlapping ROs. Accordingly, RO#0 of NES PRACH configuration #1(1102) can be mapped to SSB#0, RO#2 to SSB#1, and RO#1 to SSB#0, RO#3 to SSB#1. Afterwards, the above RO validity verification method can be applied. (For example, if the RO validity verification method is applied later, since the SSBs corresponding to the overlapping ROs (RO#0 of PRACH configuration #0(1101) and RO#0 of NES PRACH configuration #1(1102) and RO#1 of PRACH configuration #0(1101) and RO#2 of NES PRACH configuration #1(1102)) are the same, all overlapping ROs can be determined to be valid.)

[0166] In the case of a terminal, a PRACH can be transmitted based on a beam of a re-mapped (or corresponding) SSB in one RO selected from among valid PRACH occasions according to the method described above. Through the above methods, an overlapping resolution and a PRACH transmission method between ROs configured through different PRACH configurations can be provided. Although the above embodiment of the present disclosure has been described as an example in which only one SSB is mapped to an RO and each PRACH configuration supports one non-FDMed RO (in the time domain), the contents of the present disclosure are not limited to the above embodiment and can be extended and applied even when multiple SSBs are mapped to one RO and multiple ROs are FDMed. In addition, whether the overlapping ROs are supported simultaneously can be determined according to the setting of the preamble or PRACH format corresponding to the RO. For example, when different PRACH formats or preambles are configured for each RO, the NES RO can be omitted according to the valid rule. Alternatively, regardless of the above settings, the base station may support PRACH reception through two ROs, which may be determined based on the configuration information of the base station.

[0167] FIG. 12 is a diagram illustrating another example of a PRACH adaptation operation of a base station according to an embodiment of the present disclosure.

[0168] Referring to FIG. 12, the base station can set two different PRACH configurations to the terminal through upper layer signaling. More specifically, the base station can set a PRACH occasion#0 (1201) with a long period and a NES PRACH occasion#1 (1202) with a short period for applying PRACH adaptation to the terminal. At this time, the PRACH occasions according to the two PRACH configuration settings can overlap at least partially in the time domain, the frequency domain, or the time and frequency domains. At this time, if the beams of the corresponding PRACH occasion and the QCLed SSB at the base station are different, the base station can support only a specific PRACH occasion or support multiple PRACH occasions depending on its capabilities (e.g., the number of panels, whether mTRP operation is performed, or whether multi-beam operation is performed).

[0169] A UE may apply PRACH priority and / or dropping rules between two overlapping PRACH occasions for PRACH transmission. More specifically, the UE may receive from the base station a PRACH occasion #0 (1201) according to PRACH configuration #0 that does not apply PRACH adaptation and a PRACH occasion #1 (1202) according to NES PRACH configuration #1 that takes PRACH adaptation into account. At this time, RO#0 (1203) of PRACH configuration #0 and RO#0 (1204) of NES PRACH configuration #1 may overlap in the time domain. The UE may always prioritize the RO corresponding to PRACH occasion #0 (1201), which is the default, and omit the RO corresponding to PRACH occasion#1 (1202). This allows the UE to prioritize the PRACH occasion for PRACH transmission of UEs that do not support PRACH adaptation, thereby resolving an issue of UEs that do not support PRACH adaptation. That is, the above method can avoid contention that may occur when transmitting PRACH to terminals that do not support NES PRACH adaptation, and can improve interference between them. Through the above operation, the terminal can check the validity of the PRACH occasion, and transmit the PRACH in an RO determined based on at least one of the following: previous PRACH transmission, base station configuration information, or NES RO priority transmission rules among the valid ROs.

[0170] After the above valid PRACH occasion is determined, the terminal can perform SSB-to-RO mapping again through one of the following methods.

[0171] [Method 3-1]

[0172] The UE can determine a valid PRACH occasion according to a priority rule that gives priority to an RO corresponding to the default PRACH configuration among ROs set to different PRACH configurations. Thereafter, SSB-to-mapping can be continuously applied to valid PRACH occasions excluding the PRACH occasion that has been omitted. For example, according to FIG. 12, if RO#0 of PRACH occasion #0 (1201) overlaps with RO#0 of NES PRACH occasion #1 (1202), and RO#1 based on PRACH occasion #0 (1201) and RO#2 based on NES PRACH occasion #1 (1202) overlap, the RO corresponding to the default PRACH configuration is given priority, so RO#0 and RO#1 based on PRACH occasion #0 (1201) are determined to be valid. RO#0 and RO#2 based on NES PRACH occasion #1 (1202) are determined to be invalid and can be omitted. Accordingly, the terminal determines that RO#1 and RO#3 among RO#0 to RO#3 corresponding to NES PRACH configuration #1 are valid, and SSB#0 can be mapped to NES RO#1 and SSB#1 can be mapped to NES RO#3 (1205). Through this, the number of ROs connected per SSB can be distributed evenly, so that beam operation with the same PRACH performance can be supported.

[0173] [Method 3-2]

[0174] The terminal independently applies consecutive SSB-to-RO mapping to ROs set with different PRACH configurations, and a specific RO can be omitted according to the priority rule thereafter. At this time, the SSB-to-RO mapping applied for the initial priority rule can be applied as is. For example, according to FIG. 12, RO#0 of PRACH occasion #0 (1201) overlaps with RO#0 of NES PRACH occasion #1 (1202), and RO#1 of PRACH occasion #0 (1201) overlaps with RO#2 of NES PRACH occasion #1 (1202). At this time, since the RO corresponding to the default PRACH configuration is given priority, RO#0 and RO#1 of PRACH occasion #0 (1201) are determined to be valid. RO#0 and RO#2 of NES PRACH occasion #1 (1202) are determined to be invalid and can be omitted. Even so, since the SSB-to-RO mapping does not change, the SSB mapped to RO#1 set by the NES configuration can become SSB#1, and the SSB mapped to RO#3 can become SSB#3 (1206). The above method can reduce the complexity of the terminal.

[0175] In the case of a terminal, a PRACH can be transmitted based on a beam of a re-mapped (or corresponding) SSB in one RO selected from among valid PRACH occasions according to the above-described method. Through the above methods, an overlapping resolution and a PRACH transmission method between ROs configured through different PRACH configurations can be provided. Although the above embodiment of the present disclosure exemplifies a case where only one SSB is mapped to an RO and each PRACH configuration supports one non-FDMed RO (in the time domain), the contents of the present disclosure are not limited by the above embodiment and can be extended and applied to a case where multiple SSBs are mapped to one RO and multiple ROs are FDMed.

[0176] In addition, in the example of FIG. 12, the explanation is centered on the rule that prioritizes the RO corresponding to the default PRACH configuration #0 (1201), but the above method can be similarly applied to the rule that prioritizes the RO corresponding to the NES PRACH configuration #1 (1202) that takes PRACH adaptation into consideration.

[0177] Next, as shown in FIGS. 10, 11, and 12, a base station sets a PRACH configuration PRACH occasion#0 having a long period for a terminal and a PRACH occasion#1 having a short period for applying PRACH adaptation, and when PRACH occasions according to the two PRACH configuration settings overlap at least partially in the time domain, the frequency domain, or the time and frequency domains, a method for the terminal to receive a random access response (RAR) from the base station as a response to the PRACH will be described.

[0178] The RAR can be transmitted from the base station via a downlink data channel, and at this time, the CRC included in the PDCCH that schedules the downlink data channel can be scrambled with a random access - radio network temporary identifier (RA-RNTI). The RA-RNTI can be calculated by the following mathematical expression 2.

[0179] [Equation 2]

[0180] RA-RNTI = 1 + s_id + 14×t_id + 14×80×f_id + 14×80×8×ul_carrier_id

[0181] Here, s_id is the index of the first OFDM symbol of the PRACH occasion (0≤s_id<14), t_id is the index of the first slot of the PRACH occasion in the system frame (0≤t_id<80), f_id is the index of the PRACH occasion in the frequency domain (0≤f_id<8), and ul_carrier_id is the id of the uplink carrier used for PRACH transmission, which is assigned 0 for a normal carrier and 1 for a SUL carrier.

[0182] At this time, if the base station transmits the RAR (PDCCH and PDSCH) by the RA-RNTI calculated by the RA-RANTI calculation formula in response to the PRACHs transmitted by terminals A and B in the PRACH occasion#0 and PRACH occasion#1, respectively, the terminals A and B may not be able to know to which terminal the RAR is transmitted. That is, if PRACH occasion#0 and PRACH occasion#1 overlap in the time domain, or if s_id, t_id, f_id, and ul_carrier_id are the same even if each PRACH configuration (or PRACH configuration index) indicating PRACH occasion#0 and PRACH occasion#1 is different, the RA-RATI calculated by the formula may be the same. If the terminals receive the RAR by the same RA-RNTI, the contention can be resolved only when msg3 is transmitted and up to msg4 are received. In this case, a terminal that has not completed random access must start PRACH transmission again, which may cause a delay in random access.

[0183] As described above, a method is needed to distinguish RA-RNTI values ​​for terminals that transmit PRACH in PRACH occasion#0 and PRACH occasion#1, respectively.

[0184] (Method 1)

[0185] A parameter for an additional PRACH occasion may be introduced into the formula for calculating the RA-RNTI. In the PRACH configuration for setting up PRACH occasion #0 used by all terminals in the cell, including existing terminals, the value for how many PRACHs will be multiplexed in the frequency domain is given as msg1-FDM. Accordingly, the f_id value for the additional PRACH occasion #1 may start from msg1-FDM, and when the f_id for the additional PRACH occasion #1 is indicated by f'_id, f'_id = f_id + msg1-FDM, where msg1-FDM≤f'_id<8, and 8 is just an example. Finally, when transmitting a PRACH in an additional PRACH occasion, the RA-RNTI value may be calculated as in the following mathematical formula 3.

[0186] [Equation 8]

[0187] RA-RNTI = 1 + s_id + 14×t_id + 14×80×f’_id + 14×80×8×ul_carrier_id

[0188] (Method 2)

[0189] Method 2 is the same as Method 1 in that it introduces parameters for additional PRACH occasions into the formula for calculating RA-RNTI, but it applies a similar method to other parameters as well as f_id. When a symbol offset, a slot offset, a frequency offset, etc. are set in a PRACH configuration indicating an additional PRACH occasion#1, and s_id for the additional PRACH occasion#1 is indicated as s'_id, t_id is indicated as t'_id, and f_id is indicated as f'_id, s'_id=s_id+s_offset, t'_id=t_id+t_offset, f'_id=f_id+f_offset, where s_offset ≤ s'_id < 14, t_offset ≤ t'_id < 80, and f_offset ≤ f'_id < 8. An offset may be applied as described above to at least one of the other parameters other than f_id. The values ​​described above are merely examples. For example, if an offset is applied to other parameters as described above, and a PRACH is ultimately transmitted in an additional PRACH occasion, the RA-RNTI value can be calculated as shown in the following mathematical expression 4.

[0190] [Equation 4]

[0191] RA-RNTI = 1 + s'_id + 14×t'_id + 14×80×f'_id + 14×80×8×ul_carrier_id

[0192] (Method 3)

[0193] The RA-RNTI for an additional PRACH occasion can be calculated based on a formula for a separate calculation. That is, the RA-RNTI calculation formula for the existing PRACH occasion#0 remains the same, and the RA-RNTI calculated value for the additional PRACH occasion#1 can be a value calculated using the existing RA-RNTI calculation formula based on PRACH occasion#1 plus the maximum value that can be calculated for the RA-RNTI in the existing PRACH occasion#0 as an offset. Finally, when transmitting a PRACH in an additional PRACH occasion, the RA-RNTI value can be calculated as in the following mathematical formula 5.

[0194] [Equation 5]

[0195] RA-RNTI = RA-RNTI_max.legacy + 1 + s_id + 14×t_id + 14×80×f_id + 14×80×8×ul_carrier_id

[0196] RA-RNTI_max.legacy = 1 + 13 + 14×79 + 14×80×7 + 14×80×8×1

[0197] (Method 4)

[0198] A UE capable of transmitting a PRACH in an additional PRACH occasion may not expect that the additional PRACH occasion overlaps with an existing PRACH occasion in the time domain. Or / and, the UE may expect that at least one value among s_id, t_id, f_id, ul_carrier_id indicated in a PRACH configuration (or PRACH configuration index) that sets the additional PRACH occasion is different from at least one value among s_id, t_id, f_id, ul_carrier_id indicated in a PRACH configuration (or PRACH configuration index) that sets a PRACH occasion that applies to all UEs. That is, the terminal can determine that PRACH occasion#0 and PRACH occasion#1 do not overlap in the time domain, or that at least one value among s_id, t_id, f_id, and ul_carrier_id determined by PRACH occasion#0 is different from at least one value among s_id, t_id, f_id, and ul_carrier_id determined by PRACH occasion#1.

[0199] The formula for calculating the RA-RNTI described above is only an example, and the RA-RNTI may be determined using at least one of information related to time domain resources of the additional PRACH occasion, information related to frequency domain resources of the additional PRACH occasion, or information related to an uplink carrier where the additional PRACH occasion is located. The information related to time domain resources of the additional PRACH occasion, the information related to frequency domain resources of the additional PRACH occasion, or the information related to an uplink carrier where the additional PRACH occasion is located may be determined by the method described above (for example, by adding an offset).

[0200] The proposed methods of the present disclosure described above can be performed in combination with each other.

[0201] FIG. 13 is a flowchart illustrating the operation of a terminal to which an energy-saving method for a wireless communication system according to one embodiment of the present disclosure is applied. Various modifications may be made to the method illustrated in the flowchart of FIG. 13 . 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, steps may be omitted or replaced with other steps.

[0202] Based on Fig. 13, the base station explains the operation of the terminal for PRACH adaptation operation for energy saving.

[0203] Referring to FIG. 13, a terminal may receive two different pieces of PRACH configuration information from a base station via higher layer signaling (e.g., RRC or SIB) or DCI (1301). The two pieces of PRACH configuration information may be received together or in separate messages, and at least one piece of PRACH configuration information may be predetermined. Based on the configuration information, the terminal may determine to perform PRACH transmission in an additional PRACH occasion among the two different PRACH occasions (1302). This determination may be performed based on at least one of the methods described above. The terminal may receive an RAR based on an RA-RNTI calculated by the present invention (1303). The RA-RNTI for the additional PRACH occasion may be calculated by a combination of at least one of the methods described above.

[0204] For specific details of terminal operation according to one embodiment of the present disclosure described above, reference may be made to the description of one embodiment of the present disclosure described above.

[0205] FIG. 14 is a flowchart illustrating the operation of a base station to which an energy-saving method for a wireless communication system according to one embodiment of the present disclosure is applied. Various modifications may be made to the method illustrated in the flowchart of FIG. 14 . 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, steps may be omitted or replaced with other steps.

[0206] Referring to FIG. 14, a base station can transmit two different PRACH configuration settings to a terminal via higher layer signaling (e.g., RRC or SIB) or DCI (1401). The two different PRACH configuration settings may be transmitted together or in separate messages, and at least one PRACH configuration setting may be predetermined. Based on the configuration information, the base station can receive a PRACH in an additional PRACH occasion among the two different PRACH occasions (1402). The terminal can transmit a PRACH in the additional PRACH occasion, and whether the PRACH is transmitted or received in the additional PRACH occasion can be determined by the base station and the terminal through a combination of at least one of the methods described above. The base station can transmit an RAR based on an RA-RNTI calculated by the present invention (1403). The RA-RNTI for the additional PRACH occasion can be calculated through a combination of at least one of the methods described above.

[0207] For specific details of the base station operation according to one embodiment of the present disclosure described above, reference may be made to the description of one embodiment of the present disclosure described above.

[0208] 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.

[0209] The proposed methods of the present disclosure described above can be performed by the terminal of FIG. 15 and the base station of FIG. 16.

[0210] FIG. 15 is a block diagram of a terminal according to one embodiment of the present disclosure.

[0211] Referring to FIG. 15, a terminal (1500) may include a transceiver (1501), a control unit (e.g., a processor) (1502), and a storage unit (e.g., a memory) (1503). The transceiver (1501), the control unit (1502), and the storage unit (1503) of the terminal (1500) may operate according to at least one or a combination of methods corresponding to the above-described embodiments. However, the components of the terminal (1500) are not limited to the illustrated example. According to other embodiments, the terminal (1500) may include more or fewer components than the components described above. In addition, in certain cases, the transceiver (1501), the control unit (1502), and the storage unit (1503) may be implemented in the form of a single chip.

[0212] The transceiver (1501) may, according to one embodiment, be composed of a transmitter and a receiver. The transceiver (1501) may transmit and receive signals with a base station. The signals may include control information and data. The transceiver (1501) 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 (1501) may receive a signal through a wireless channel and output the signal to the control unit (1502), and transmit the signal output from the control unit (1502) through the wireless channel.

[0213] The control unit (1502) may control a series of procedures that the terminal (1500) may perform according to the embodiments of the present disclosure described above. For example, the control unit (1502) 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 (1502) may include at least one processor. For example, the control unit (1502) 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).

[0214] The storage unit (1503) can store control information (e.g., information related to channel estimation using DMRSs transmitted on PUSCH included in a signal acquired from the terminal (1500)) or data, and can have an area for storing data required for controlling the control unit (1502) and data generated during control by the control unit (1502).

[0215] FIG. 16 is a block diagram of a base station according to one embodiment of the present disclosure.

[0216] Referring to FIG. 16, a base station (1600) may include a transceiver (1601), a control unit (e.g., a processor) (1602), and a storage unit (e.g., a memory) (1603). The transceiver (1601), the control unit (1602), and the storage unit (1603) of the base station (1600) may operate according to at least one or a combination of the methods corresponding to the above-described embodiments. However, the components of the base station (1600) are not limited to the illustrated example. According to other embodiments, the base station (1600) may include more or fewer components than the components described above. In addition, in certain cases, the transceiver (1601), the control unit (1602), and the storage unit (1603) may be implemented in the form of a single chip.

[0217] The transceiver (1601) may, according to one embodiment, be composed of a transmitter and a receiver. The transceiver (1601) may transmit and receive signals with a terminal. The signals may include control information and data. The transceiver (1601) 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 (1601) may receive a signal through a wireless channel and output the signal to the control unit (1602), and may transmit a signal output from the control unit (1602) through the wireless channel.

[0218] The control unit (1602) may control a series of procedures so that the base station (1600) can operate according to the embodiments of the present disclosure described above. For example, the control unit (1602) 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 (1602) may include at least one processor. For example, the control unit (1602) 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).

[0219] The storage unit (1603) can store control information (e.g., information related to channel estimation generated using DMRSs transmitted on a PUSCH determined by the base station (1600), data, control information received from a terminal, or data, and can have an area for storing data required for controlling the control unit (1602) and data generated during control by the control unit (1602).

[0220] 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 herein may be utilized, such features may be utilized in any other suitable system.

[0221] 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. Nothing in this disclosure should be construed as implying that any specific element, step, or function is essential to the scope of the claims. The scope of the patented subject matter is defined by the claims.

Claims

1. In a method performed by a terminal of a communication system, A step of obtaining additional PRACH (physical random access channel) configuration information; A step of transmitting a PRACH preamble to a base station at a PRACH occasion based on the additional PRACH configuration information; A step of checking RA-RNTI (random access - radio network temporary identifier) ​​based on the above PRACH occasion; A step of receiving a PDCCH (physical downlink control channel) based on the RA-RNTI from the base station, wherein the PDCCH schedules a downlink data channel; and A step of receiving a random access response (RAR) from the base station on the downlink data channel, A method characterized in that the above RA-RNTI is verified based on a frequency domain index of the PRACH occasion, and the minimum value of the frequency domain index is the number of FDMed (frequency division multiplexed) PRACH occasions included in conventional PRACH configuration information.

2. In paragraph 1, The above RA-RNTI is verified based on the formula below, RA-RNTI = 1 + s_id + 14×t_id + 14×80×f'_id + 14×80×8×ul_carrier_id A method characterized in that s_id is an index of a first symbol of the PRACH occasion, t_id is an index of a first slot of the PRACH occasion, f_id is the frequency domain index of the PRACH occasion, and ul_carrier_id is an identifier of an uplink carrier used for transmission of the PRACH preamble.

3. A method according to claim 1, wherein the frequency domain index is the sum of the number of FDMed PRACH occasions and the frequency domain index corresponding to the PRACH occasion.

4. In paragraph 1, A method characterized in that the additional PRACH configuration information is received from the base station through upper layer signaling.

5. In the method performed by the base station of the communication system, A step of obtaining additional PRACH (physical random access channel) configuration information; A step of receiving a PRACH preamble at a PRACH occasion related to the additional PRACH configuration information from the terminal; A step of checking RA-RNTI (random access - radio network temporary identifier) ​​based on the above PRACH occasion; A step of transmitting a PDCCH (physical downlink control channel) based on the RA-RNTI to the terminal, wherein the PDCCH schedules a downlink data channel; and A step of transmitting a random access response (RAR) to the terminal on the downlink data channel, A method characterized in that the above RA-RNTI is verified based on a frequency domain index of the PRACH occasion, and the minimum value of the frequency domain index is the number of FDMed (frequency division multiplexed) PRACH occasions included in conventional PRACH configuration information.

6. In paragraph 5, The above RA-RNTI is verified based on the formula below, RA-RNTI = 1 + s_id + 14×t_id + 14×80×f'_id + 14×80×8×ul_carrier_id A method characterized in that s_id is an index of a first symbol of the PRACH occasion, t_id is an index of a first slot of the PRACH occasion, f_id is the frequency domain index of the PRACH occasion, and ul_carrier_id is an identifier of an uplink carrier used for transmission of the PRACH preamble.

7. A method according to claim 5, wherein the frequency domain index is the sum of the number of FDMed PRACH occasions and the frequency domain index corresponding to the PRACH occasion.

8. In paragraph 5, A method characterized in that the above additional PRACH configuration information is transmitted to the terminal through upper layer signaling.

9. At the terminal of the communication system, At least one transceiver; At least one processor communicatively connected to said at least one transceiver; and Communicably connected to at least one processor, and executable individually or in any combination of said at least one processor, such that said terminal: Obtain additional PRACH (physical random access channel) configuration information, Transmitting a PRACH preamble to the base station at a PRACH occasion based on the above additional PRACH configuration information, Based on the above PRACH occasion, check the RA-RNTI (random access - radio network temporary identifier), Receive a PDCCH (physical downlink control channel) based on the RA-RNTI from the base station, and the PDCCH schedules a downlink data channel, and A memory storing a command to receive a random access response (RAR) from the base station on the downlink data channel; A terminal characterized in that the RA-RNTI is verified based on a frequency domain index of the PRACH occasion, and the minimum value of the frequency domain index is the number of FDMed (frequency division multiplexed) PRACH occasions included in conventional PRACH configuration information.

10. In paragraph 9, The above RA-RNTI is verified based on the formula below, RA-RNTI = 1 + s_id + 14×t_id + 14×80×f'_id + 14×80×8×ul_carrier_id A terminal characterized in that s_id is an index of a first symbol of the PRACH occasion, t_id is an index of a first slot of the PRACH occasion, f_id is the frequency domain index of the PRACH occasion, and ul_carrier_id is an identifier of an uplink carrier used for transmission of the PRACH preamble.

11. A terminal according to claim 9, wherein the frequency domain index is the sum of the number of FDMed PRACH occasions and the frequency domain index corresponding to the PRACH occasion.

12. In paragraph 9, A terminal characterized in that the additional PRACH configuration information is received from the base station through upper layer signaling.

13. In the base station of the communication system, At least one transceiver; At least one processor communicatively connected to said at least one transceiver; and Communicably connected to at least one processor, and executable individually or in any combination of said at least one processor, such that said base station: Obtain additional PRACH (physical random access channel) configuration information, Receive a PRACH preamble from the terminal at a PRACH occasion related to the additional PRACH configuration information, Based on the above PRACH occasion, check the RA-RNTI (random access - radio network temporary identifier), The terminal transmits a PDCCH (physical downlink control channel) based on the RA-RNTI, and the PDCCH schedules a downlink data channel, and A memory storing a command to transmit a random access response (RAR) to the terminal on the downlink data channel; A base station characterized in that the RA-RNTI is verified based on a frequency domain index of the PRACH occasion, and the minimum value of the frequency domain index is the number of FDMed (frequency division multiplexed) PRACH occasions included in conventional PRACH configuration information.

14. In paragraph 13, The above RA-RNTI is verified based on the formula below, RA-RNTI = 1 + s_id + 14×t_id + 14×80×f'_id + 14×80×8×ul_carrier_id A base station, characterized in that s_id is an index of a first symbol of the PRACH occasion, t_id is an index of a first slot of the PRACH occasion, f_id is the frequency domain index of the PRACH occasion, and ul_carrier_id is an identifier of an uplink carrier used for transmission of the PRACH preamble.

15. A base station according to claim 13, wherein the frequency domain index is the sum of the number of FDMed PRACH occasions and the frequency domain index corresponding to the PRACH occasion.

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