Method and device for generating downlink control information in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. According to an embodiment of the present disclosure, a method for processing a control signal in a wireless communication system may include the steps of: receiving a first control signal transmitted from a base station; processing the received first control signal; and transmitting, to the base station, a second control signal generated on the basis of the processing.

Description

Method and device for generating downlink control information in a 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 an apparatus and method for a terminal to perform the reception of downlink control information.

[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 frequency bands below 6 GHz ('Sub 6 GHz'), such as 3.5 gigahertz (3.5 GHz), but also in ultra-high frequency bands called millimeter waves (mmWave), such as 28 GHz and 39 GHz ('Above 6 GHz'). In addition, for 6G mobile communication technology, which is referred to as a system beyond 5G, implementation in the terahertz band (e.g., the 3 terahertz (3 THz) band at 95 GHz) is being considered to achieve transmission speeds 50 times faster and ultra-low latency reduced to one-tenth compared to 5G mobile communication technology.

[0003] In the early stages of 5G mobile communication technology, aiming to satisfy service support and performance requirements for enhanced Mobile BroadBand (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), technologies such as beamforming and Massive MIMO to mitigate path loss and increase transmission distance in ultra-high frequency bands, support for various numerologies (such as the operation of multiple subcarrier spacings) and dynamic operation of slot formats for the efficient utilization of ultra-high frequency resources, initial access techniques to support multi-beam transmission and broadband, definition and operation of Band-Width Parts (BWP), Low Density Parity Check (LDPC) codes for high-volume data transmission, new channel coding methods such as Polar Codes for the reliable transmission of control information, and L2 pre-processing (L2 Standardization has been carried out for pre-processing, network slicing which provides a dedicated network specialized for specific services, and other methods.

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

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

[0006] When such 5G mobile communication systems are commercialized, connected devices, which are increasing explosively, will be connected to communication networks. Accordingly, it is expected that there will be a need to enhance the functionality and performance of 5G mobile communication systems and to integrate the operation of connected devices. To this end, new research is planned to be conducted on 5G performance improvement and complexity reduction, support for AI services, support for metaverse services, and drone communication using eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] Furthermore, the advancement of these 5G mobile communication systems encompasses multi-antenna transmission technologies such as new waveforms to guarantee coverage in the terahertz band of 6G mobile communication technology, Full Dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas; metamaterial-based lenses and antennas to improve terahertz band signal coverage; high-dimensional spatial multiplexing technology using OAM (Orbital Angular Momentum); and Reconfigurable Intelligent Surface (RIS) technology; as well as Full Duplex technology for enhancing frequency efficiency and system networks in 6G mobile communication technology; AI-based communication technologies that realize system optimization by utilizing satellites and AI from the design stage and internalizing end-to-end AI support functions; and the realization of services of complexity exceeding the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources. It could serve as a foundation for the development of next-generation distributed computing technologies.

[0008] As described above and with the advancement of wireless communication systems, it has become possible to provide various services, and therefore, measures to smoothly provide these services are required, and in particular, a method for the terminal to efficiently perform SBFD (subband non-overlapping full duplex) operations is required.

[0009] The disclosed embodiment aims to provide an apparatus and method capable of effectively providing services in a mobile communication system.

[0010] A mobile communication (or wireless communication) system according to one embodiment of the present disclosure includes a method for receiving PDSCH in a subband non-overlapping full duplex (SBFD).

[0011] The disclosed embodiments provide an apparatus and a method capable of effectively providing services in a mobile communication system. The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure pertains from the description below.

[0012] FIG. 1 is a diagram illustrating the basic structure of the time-frequency domain in a wireless communication system according to one embodiment of the present disclosure.

[0013] FIG. 2 is a drawing illustrating a frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

[0014] FIG. 3 is a drawing illustrating an example of a bandwidth portion setting in a wireless communication system according to an embodiment of the present disclosure.

[0015] FIG. 4 is a diagram illustrating an example of setting a control area of ​​a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.

[0016] FIG. 5 is a diagram illustrating the structure of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.

[0017] FIG. 6 is a diagram illustrating a method for transmitting and receiving data in consideration of a downlink data channel and rate matching resources between a base station and a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0018] FIG. 7 is a diagram illustrating an example of frequency axis resource allocation of a PDSCH in a wireless communication system according to one embodiment of the present disclosure.

[0019] FIG. 8 is a diagram illustrating an example of time axis resource allocation of PDSCH in a wireless communication system according to one embodiment of the present disclosure.

[0020] FIG. 9 is a diagram illustrating an example of time-axis resource allocation according to the subcarrier interval of a data channel and a control channel in a wireless communication system according to one embodiment of the present disclosure.

[0021] FIG. 10 is a diagram illustrating the wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation, dual connectivity situation in a wireless communication system according to one embodiment of the present disclosure.

[0022] FIG. 11 is a drawing illustrating an arbitrary connection procedure in a wireless communication system according to one embodiment of the present disclosure.

[0023] FIG. 12 is a diagram illustrating the process of a terminal monitoring fallback DCI in chronological order during an arbitrary connection process in an NR system according to one embodiment of the present disclosure.

[0024] FIG. 13 is a flowchart illustrating an operation according to one embodiment of the present disclosure.

[0025] FIG. 14 is a drawing illustrating various purposes of DCI format 1_1 introduced in NR according to one embodiment of the present disclosure.

[0026] FIG. 15 is a flowchart illustrating an operation according to one embodiment of the present disclosure.

[0027] FIG. 16 is a drawing illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0028] FIG. 17 is a drawing illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0029] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0030] In describing the embodiments, technical details that are well known in the technical field to which this disclosure belongs and are not directly related to this disclosure are omitted. This is intended to convey the essence of this disclosure more clearly without obscuring it by omitting unnecessary explanations.

[0031] For the same reason, some components in the attached drawings have been exaggerated, omitted, or schematically depicted. Additionally, the dimensions of each component do not entirely reflect their actual dimensions. Identical or corresponding components in each drawing have been assigned the same reference numbers.

[0032] The advantages and features of the present disclosure, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components. Furthermore, in describing the present disclosure, if it is determined that a detailed description of related functions or configurations might unnecessarily obscure the essence of the present disclosure, such detailed description is omitted. Additionally, the terms described below are defined considering their functions in the present disclosure, and these may vary depending on the intentions or conventions of the user or operator. Therefore, their definitions should be based on the content throughout the specification.

[0033] Hereinafter, a base station is an entity that performs resource allocation for terminals and may be at least one of a gNode B, eNode B, Node B, BS (Base Station), wireless access unit, base station controller, or a node on a network. A terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or a multimedia system capable of performing communication functions. In this disclosure, a downlink (DL) refers to a wireless transmission path of a signal transmitted by a base station to a terminal, and an uplink (UL) refers to a wireless transmission path of a signal transmitted by a terminal to a base station. Furthermore, while LTE or LTE-A systems may be described as examples below, embodiments of this disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, 5th generation mobile communication technologies (5G, new radio, NR) developed after LTE-A may be included therein, and the 5G below may be a concept that includes existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems with some modifications made at the discretion of a person with skilled technical knowledge, without significantly departing from the scope of the present disclosure. The contents of the present disclosure are applicable to FDD and TDD systems.

[0034] At this point, it will be understood that each block of the process flow diagrams and combinations of the flow diagrams can be executed by computer program instructions. Since these computer program instructions can be loaded into the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, the instructions executed through the processor of the computer or other programmable data processing equipment create means to perform the functions described in the flow diagram block(s). Since these computer program instructions can also be stored in computer-available or computer-readable memory that can be directed toward the computer or other programmable data processing equipment to implement the function in a specific way, the instructions stored in computer-available or computer-readable memory can also produce a manufactured item containing instruction means to perform the function described in the flow diagram block(s). Since computer program instructions can be loaded onto a computer or other programmable data processing equipment, instructions that perform a series of operation steps on the computer or other programmable data processing equipment to create a process executed by the computer can also provide steps for executing the functions described in the flowchart block(s).

[0035] Additionally, each block may represent a module, segment, or part of code containing one or more executable instructions for executing a specific logical function(s). It should also be noted that in some alternative execution examples, the functions mentioned in the blocks may occur out of order. For example, two blocks described in succession may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order according to their corresponding functions.

[0036] In this embodiment, the term "part" refers to a software or hardware component such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and the "part" performs certain roles. However, the meaning of "part" is not limited to software or hardware. The "part" may be configured to reside in an addressable storage medium or may be configured to run one or more processors. Accordingly, as an example, the "part" includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and "parts" may be combined into a smaller number of components and "parts" or further separated into additional components and "parts." In addition, the components and '~parts' may be implemented to utilize one or more CPUs within the device or secure multimedia card. Also, in the embodiment, the '~part' may include one or more processors.

[0037] In describing the present disclosure below, if it is determined that a detailed description of related known functions or configurations could unnecessarily obscure the essence of the present disclosure, such detailed description will be omitted. Embodiments of the present disclosure may be described below with reference to the attached drawings.

[0038] Wireless communication systems are evolving from providing early voice-oriented services to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as communication standards like 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 802.16e.

[0039] As a representative example of a broadband wireless communication system, the LTE system employs the Orthogonal Frequency Division Multiplexing (OFDM) method for the downlink (DL) and the Single Carrier Frequency Division Multiple Access (SC-FDMA) method for the uplink (UL). The uplink refers to a wireless link through which a terminal (User Equipment (UE) or Mobile Station (MS)) transmits data or control signals to a base station (eNode B, or base station (BS)), and the downlink refers to a wireless link through which a base station transmits data or control signals to a terminal. The aforementioned multiple access method can distinguish the data or control information of each user by allocating and operating time-frequency resources to be sent for each user so that they do not overlap, that is, so that orthogonality is established.

[0040] As a future communication system following LTE, for example, a 5G communication system must be able to freely reflect the diverse requirements of users and service providers, and therefore, services that satisfy various requirements simultaneously must be supported. Services being considered for a 5G communication system include enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliability Low Latency Communication (URLLC).

[0041] eMBB aims to provide data transmission speeds that are superior to 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 10 Gbps in the uplink from the perspective of a single base station. Furthermore, while providing these peak data rates, the 5G communication system must also provide an increased user-perceived data rate. To satisfy these requirements, it necessitates improvements in various transmission and reception technologies, including enhanced Multi-Input Multi-Output (MIMO) transmission technology. Additionally, while LTE transmits signals using a maximum bandwidth of 20 MHz in the 2 GHz band, the 5G communication system can meet the data transmission speeds required by using a frequency bandwidth wider than 20 MHz in frequency bands of 3–6 GHz or above 6 GHz.

[0042] Simultaneously, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide IoT, mMTC requires support for a large number of terminal connections within a cell, improved terminal coverage, enhanced battery life, and reduced terminal costs. Since IoT devices are attached to various sensors and equipment to provide communication functions, the system must be able to support a large number of terminals within a cell (e.g., 1,000,000 terminals / km²). Furthermore, due to the nature of the service, terminals supporting mMTC are likely to be located in dead zones not covered by cells, such as building basements; therefore, they may require wider coverage compared to other services provided by 5G communication systems. Terminals supporting mMTC must consist of low-cost devices, and since it is difficult to frequently replace terminal batteries, a very long battery life of 10 to 15 years may be required.

[0043] Finally, URLLC is a mission-critical cellular-based wireless communication service. Examples include services used for remote control of robots or machinery, industrial automation, unmanned aerial vehicles, remote health care, and emergency alerts. Therefore, the communication provided by URLLC must offer very low latency and very high reliability. For instance, services supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds and simultaneously require a packet error rate of 10⁻⁵ or less. Consequently, for services supporting URLLC, 5G systems must provide a Transmit Time Interval (TTI) smaller than other services, and design considerations may be required to allocate wide resources within the frequency band to ensure the reliability of the communication link.

[0044] The three 5G services, namely eMBB, URLLC, and mMTC, can be multiplexed and transmitted within a single system. In this case, different transmission and reception techniques and parameters may be used between the services to satisfy the different requirements of each service. Of course, 5G is not limited to the three services mentioned above.

[0045] [NR Time-Frequency Resources]

[0046] The frame structure of the 5G system will be explained in more detail below with reference to the drawings.

[0047] FIG. 1 is a diagram illustrating the basic structure of the time-frequency domain in a wireless communication system according to one embodiment of the present disclosure.

[0048] Referring to FIG. 1, the horizontal axis of FIG. 1 represents the time domain, and the vertical axis represents the frequency domain. In the time and frequency domains, the basic unit of a resource is a resource element (RE, 101), which can be defined as one OFDM (Orthogonal Frequency Division Multiplexing) symbol (102) on the time axis and one subcarrier (103) on the frequency axis. In the frequency domain (For example, 12) consecutive REs can form a single resource block (Resource Block, RB, 104).

[0049] FIG. 2 is a drawing illustrating a frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

[0050] FIG. 2 illustrates an example of a frame (200), subframe (201), and slot (202) structure. One frame (200) can be defined as 10ms. One subframe (201) can be defined as 1ms, and thus one frame (200) can be composed of a total of 10 subframes (201). One slot (202, 203) can be defined as 14 OFDM symbols (i.e., the number of symbols per slot ( )=14). One subframe (201) may be composed of one or more slots (202, 203), and the number of slots (202, 203) per one subframe (201) may vary depending on the setting value μ (204, 205) for the subcarrier spacing. In one example of FIG. 2, cases where μ=0 (204) and μ=1 (205) are set as the subcarrier spacing value are illustrated. When μ=0 (204), one subframe (201) may be composed of one slot (202), and when μ=1 (205), one subframe (201) may be composed of two slots (203). That is, the number of slots per one subframe ( ) may vary, and accordingly, the number of slots per frame ( ) may vary. Depending on each subcarrier spacing setting μ It can be defined by Table 1 below.

[0051] [Table 1]

[0052]

[0053] [Bandwidth Section (BWP)]

[0054] Next, the Bandwidth Part (BWP) setting in the 5G communication system will be explained in detail with reference to the drawing.

[0055] FIG. 3 is a drawing illustrating an example of a bandwidth portion setting in a wireless communication system according to an embodiment of the present disclosure.

[0056] Referring to FIG. 3, an example is shown in which the terminal bandwidth (UE bandwidth) (300) is configured into two bandwidth portions, namely bandwidth portion #1 (BWP#1) (301) and bandwidth portion #2 (BWP#2) (302). The base station may configure one or more bandwidth portions for the terminal and may configure information such as that shown in Table 2 below for each bandwidth portion.

[0057] [Table 2]

[0058]

[0059] Of course, the settings regarding the bandwidth part are not limited to the examples above, and various parameters related to the bandwidth part may be set for the terminal in addition to the setting information in Table 2. The setting information may be transmitted from the base station to the terminal via upper-layer signaling, for example, RRC (Radio Resource Control) signaling. Among the one or more configured bandwidth parts, at least one bandwidth part may be activated. Whether the configured bandwidth part is activated may be transmitted semi-statically from the base station to the terminal via RRC signaling or dynamically via DCI (Downlink Control Information).

[0060] According to one embodiment, prior to the Radio Resource Control (RRC) connection, the terminal may receive an Initial Bandwidth Part (Initial BWP) for initial connection from the base station via a Master Information Block (MIB). More specifically, during the initial connection phase, the terminal may receive configuration information for a Control Resource Set (CORESET) and a Search Space via the MIB, through which a PDCCH can be transmitted to receive system information required for initial connection (Remaining System Information; which may correspond to RMSI or System Information Block 1; SIB1). The Control Resource Set and Search Space configured via the MIB may each be considered as Identity (ID) 0. The base station may notify the terminal via the MIB of configuration information, such as frequency allocation information, time allocation information, and numerology, for Control Resource Set #0. Additionally, the base station may notify the terminal via the MIB of configuration information regarding the monitoring period and occasion for Control Resource Set #0, i.e., configuration information for Search Space #0. The terminal may consider the frequency region set as control region #0 obtained from the MIB as the initial bandwidth portion for initial access. In this case, the identifier (ID) of the initial bandwidth portion may be considered as 0.

[0061] According to one embodiment of the present disclosure, the setting of the bandwidth portion supported by a 5G communication system can be used for various purposes.

[0062] According to one embodiment, if the bandwidth supported by the terminal is smaller than the system bandwidth, this can be supported through a bandwidth portion setting. For example, by setting a frequency position of the bandwidth portion (setting information 2) to the terminal, the terminal can transmit and / or receive data at a specific frequency position within the system bandwidth.

[0063] In addition, according to one embodiment, a base station may set multiple bandwidth portions for a terminal for the purpose of supporting different numerologies. For example, to support both data transmission and / or reception using a 15 kHz subcarrier interval and a 30 kHz subcarrier interval for a terminal, two bandwidth portions may be set to subcarrier intervals of 15 kHz and 30 kHz, respectively. Different bandwidth portions may be frequency division multiplexed, and when data transmission and / or reception is to be performed at a specific subcarrier interval, the bandwidth portion set to that subcarrier interval may be activated.

[0064] In addition, according to one embodiment, a base station may set a bandwidth portion having different bandwidth sizes for the purpose of reducing the power consumption of the terminal. For example, if the terminal supports a very large bandwidth, such as 100 MHz, and always transmits and / or receives data using that bandwidth, very large power consumption may occur. In particular, in a situation where there is no traffic, performing monitoring of an unnecessary downlink control channel using a large bandwidth of 100 MHz may be very inefficient in terms of power consumption. To reduce the power consumption of the terminal, the base station may set a bandwidth portion of a relatively small bandwidth, such as 20 MHz, for the terminal. In a situation where there is no traffic, the terminal can perform monitoring operations in the 20 MHz bandwidth portion, and when data is generated, it can transmit and / or receive data using the 100 MHz bandwidth portion according to the instructions of the base station.

[0065] According to one embodiment of the present disclosure, in a method for setting a bandwidth part, terminals prior to RRC connection (Connected) may receive setting information for an Initial Bandwidth Part through a Master Information Block (MIB) during the initial connection stage. More specifically, the terminal may receive a Control Resource Set (CORESET) for a downlink control channel through which Downlink Control Information (DCI) for scheduling System Information Blocks (SIB) can be transmitted from the MIB of a Physical Broadcast Channel (PBCH). The bandwidth of the control set by the MIB may be considered as the Initial Bandwidth Part, and through the set Initial Bandwidth Part, the terminal may receive a Physical Downlink Shared Channel (PDSCH) through which SIBs are transmitted. In addition to the purpose of receiving SIBs, the Initial Bandwidth Part may also be utilized for Other System Information (OSI), paging, and Random Access.

[0066] [Bandwidth Section (BWP) Change]

[0067] When one or more bandwidth parts are set for a terminal, the base station may instruct the terminal to change (or switch, transition) the bandwidth part using the Bandwidth Part Indicator field within the DCI. For example, in FIG. 3, if the currently active bandwidth part of the terminal is Bandwidth Part #1 (301), the base station may instruct the terminal to Bandwidth Part #2 (302) using the Bandwidth Part Indicator within the DCI, and the terminal may perform a bandwidth part change to Bandwidth Part #2 (302) indicated by the received Bandwidth Part Indicator within the DCI.

[0068] As mentioned above, since DCI-based bandwidth portion changes can be directed by the DCI scheduling PDSCH or PUSCH, when a terminal receives a bandwidth portion change request, it must be able to receive or transmit the PDSCH or PUSCH scheduled by the DCI in the changed bandwidth portion without difficulty. To this end, the standard specifies the delay time (T) required when changing the bandwidth portion. BWP The requirements for ) have been specified and can be defined, for example, as shown in Table 3 below.

[0069] [Table 3]

[0070]

[0071] The requirements for bandwidth portion change delay time may support Type 1 or Type 2 depending on the terminal's capability. The terminal may report the supported bandwidth portion delay time type to the base station.

[0072] In accordance with the aforementioned requirements for the bandwidth change delay time, when a terminal receives a DCI containing a bandwidth change indicator in slot n, the terminal may complete the change to the new bandwidth portion indicated by the bandwidth change indicator at a time not later than slot n + TBWP, and may perform transmission and / or reception for the data channel scheduled by the DCI containing the bandwidth change indicator in the changed new bandwidth portion. When the base station intends to schedule a data channel to the new bandwidth portion, it may determine the time domain resource allocation for the data channel by considering the terminal's bandwidth change delay time (TBWP). That is, when the base station schedules a data channel to the new bandwidth portion, in the method of determining the time domain resource allocation for the data channel, it may schedule the data channel after the bandwidth change delay time. Therefore, the terminal may not expect the DCI indicating the bandwidth change to indicate a slot offset value (e.g., K0 or K2) smaller than the bandwidth change delay time (TBWP).

[0073] If a terminal receives a DCI indicating a bandwidth change (e.g., DCI format 1_1 or 0_1), the terminal may not perform any transmission or reception during a time interval corresponding to the time interval from the third symbol of the slot in which the PDCCH containing the DCI indicating the bandwidth change was received to the beginning of the slot indicated by the slot offset value (e.g., K0 or K2) indicated by the time domain resource allocation indicator field within the DCI indicating the bandwidth change. For example, if a terminal receives a DCI indicating a bandwidth change in slot n, and the slot offset value indicated by the DCI indicating the bandwidth change is K, the terminal may not perform any transmission or reception from the third symbol of slot n to the symbol prior to slot n+K (i.e., the last symbol of slot n+K-1).

[0074] [SS / PBCH Block]

[0075] Next, we can explain the SS (Synchronization Signal) / PBCH block in the 5G communication system.

[0076] An SS / PBCH block may refer to a physical layer channel block composed of PSS (Primary SS), SSS (Secondary SS), and PBCH. Specifically, it may be as follows.

[0077] - PSS: A signal that serves as the reference for downlink time / frequency synchronization and can provide some information about the cell ID.

[0078] - SSS: Serves as the standard for downlink time / frequency synchronization and can provide the remaining cell ID information not provided by PSS. Additionally, it can serve as a reference signal for PBCH demodulation.

[0079] - PBCH: Can provide essential system information required for the transmission and / or reception of the terminal's data channel and control channel. The essential system information may include search space-related control information representing wireless resource mapping information of the control channel, scheduling control information for a separate data channel transmitting system information, etc.

[0080] - SS / PBCH block: An SS / PBCH block can be composed of a combination of PSS, SSS, and PBCH. One or more SS / PBCH blocks can be transmitted within a time of 5ms, and each transmitted SS / PBCH block can be distinguished by an index.

[0081] The terminal can detect PSS and SSS during the initial connection phase and can decode PBCH. The terminal can obtain MIB from PBCH and, through the obtained MIB, receive a Control Resource Set (CORESET) #0 (e.g., may correspond to a control resource set with a control resource index of 0). The terminal can perform monitoring of Control Resource Set #0 by assuming that the selected SS / PBCH block and the Demodulation Reference Signal (DMRS) transmitted from Control Resource Set #0 are Quasi-Co-Locations (QCL). The terminal can receive system information through downlink control information transmitted from Control Resource Set #0. The terminal can obtain configuration information related to the Random Access Channel (RACH) required for initial connection from the received system information. The terminal can transmit a Physical RACH (PRACH) to the base station considering the selected SS / PBCH index, and the base station receiving the PRACH can obtain information regarding the SS / PBCH block index selected by the terminal. The base station can know that the terminal has selected a block among the respective SS / PBCH blocks and is monitoring control area #0 associated with the selected block.

[0082] [PDCCH: DCI related]

[0083] Next, Downlink Control Information (DCI) in 5G systems will be explained in detail.

[0084] In a 5G system, scheduling information for uplink data (or Physical Uplink Shared Channel (PUSCH)) or downlink data (or Physical Downlink Shared Channel (PDSCH)) can be transmitted from a base station to a terminal via DCI. The terminal can monitor the fallback DCI format and the non-fallback DCI format for PUSCH or PDSCH. The fallback DCI format may consist of fixed fields selected between the base station and the terminal, and the non-fallback DCI format may include configurable fields.

[0085] DCI can be transmitted through the Physical Downlink Control Channel (PDCCH) after undergoing channel coding and modulation processes. A Cyclic Redundancy Check (CRC) is attached to the DCI message payload, and the CRC can be scrambled into a Radio Network Temporary Identifier (RNTI) corresponding to the terminal's identity. Different RNTIs may be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control commands, or random access responses. In other words, the RNTI may not be transmitted explicitly but may be included in the CRC calculation process. Upon receiving a DCI message transmitted over the PDCCH, the terminal checks the CRC using the assigned RNTI; if the CRC check result is correct, the terminal knows that the message has been transmitted to it.

[0086] For example, a DCI scheduling a PDSCH for System Information (SI) can be scrambled to SI-RNTI. A DCI scheduling a PDSCH for Random Access Response (RAR) messages can be scrambled to RA-RNTI. A DCI scheduling a PDSCH for Paging messages can be scrambled to P-RNTI. A DCI notifying a Slot Format Indicator (SFI) can be scrambled to SFI-RNTI. A DCI notifying Transmit Power Control (TPC) can be scrambled to TPC-RNTI. A DCI scheduling a terminal-specific PDSCH or PUSCH can be scrambled to C-RNTI (Cell RNTI).

[0087] DCI format 0_0 can be used as a countermeasure DCI for scheduling PUSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 0_0 with the CRC scrambled with C-RNTI may include, for example, the information in Table 4. Of course, it is not limited to the following examples.

[0088] [Table 4]

[0089]

[0090] DCI format 0_1 ​​can be used as a non-defense DCI for scheduling PUSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 0_1 ​​with the CRC scrambled with C-RNTI may include, for example, the information in Table 5. Of course, it is not limited to the following examples.

[0091] [Table 5]

[0092]

[0093]

[0094] DCI format 1_0 can be used as a countermeasure DCI for scheduling PDSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 1_0 with the CRC scrambled with C-RNTI may include, for example, the information in Table 6. Of course, it is not limited to the following examples.

[0095] [Table 6]

[0096]

[0097] DCI format 1_1 can be used as a non-defense DCI for scheduling PDSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 1_1 with the CRC scrambled with C-RNTI may include, for example, the information in Table 7. Of course, it is not limited to the following examples.

[0098] [Table 7]

[0099]

[0100]

[0101] [PDCCH: CORESET, REG, CCE, Search Space]

[0102] In the following, the downlink control channel in a 5G communication system may be explained in more detail with reference to the drawings.

[0103] FIG. 4 illustrates an example of setting a control resource set (CORESET) of a downlink control channel in a wireless communication system according to an embodiment of the present disclosure. FIG. 4 may illustrate an example in which two control resources (control resource #1 (401), control resource #2 (402)) are set within a terminal bandwidth part (UE bandwidth part) (410) on the frequency axis and one slot (420) on the time axis. The control resources (401, 402) may be set to a specific frequency resource (403) within the entire terminal bandwidth part (410) on the frequency axis. On the time axis, they may be set to one or multiple OFDM symbols and can be defined as the control resource set duration (Control Resource Set Duration, 404). Referring to the example illustrated in FIG. 4, control resource #1 (401) is set to a control resource length of 2 symbols, and control resource #2 (402) is set to a control resource length of 1 symbol.

[0104] The control domain in the aforementioned 5G communication system can be configured by the base station to the terminal via upper-layer signaling (e.g., System Information, Master Information Block (MIB), Radio Resource Control (RRC) signaling). The ability to configure the control domain to the terminal may mean providing information such as the control domain identifier, the frequency location of the control domain, and the symbol length of the control domain. For example, it may include the information in Table 8 below. Of course, it may not be limited to the following examples.

[0105] [Table 8]

[0106]

[0107]

[0108] In Table 8, the tci-StatesPDCCH (simply named TCI (Transmission Configuration Indication) state) configuration information may include information on one or more SS (Synchronization Signal) / PBCH (Physical Broadcast Channel) block indices or CSI-RS (Channel State Information Reference Signal) indices that have a QCL (Quasi Co Located) relationship with the DMRS transmitted in the corresponding control area. Of course, it may not be limited to the following examples.

[0109] FIG. 5 is a diagram illustrating the structure of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.

[0110] Referring to FIG. 5, this is an example of a basic unit of time and frequency resources that can be used in a 5G communication system to configure a downlink control channel. According to FIG. 5, the basic unit of time and frequency resources that constitute the control channel can be called a REG (Resource Element Group, 503), and the REG (503) can be defined as 1 OFDM symbol (501) on the time axis and 1 PRB (Physical Resource Block, 502) on the frequency axis, i.e., 12 subcarriers. A base station can configure a downlink control channel allocation unit by concatenating REGs (503).

[0111] As illustrated in FIG. 5, if the basic unit to which a downlink control channel is allocated in 5G is called a CCE (Control Channel Element, 504), then 1 CCE (504) can be composed of multiple REGs (503). For example, if the REG (503) illustrated in FIG. 5 is described, the REG (503) can be composed of 12 REs, and if 1 CCE (504) is composed of 6 REGs (503), then 1 CCE (504) can be composed of 72 REs. When a downlink control area is established, the area can be composed of multiple CCEs (504), and a specific downlink control channel can be mapped to one or multiple CCEs (504) and transmitted according to the Aggregation Level (AL) within the control area. The CCEs (504) in the control area are distinguished by numbers, and the numbers of the CCEs (504) can be assigned according to a logical mapping method.

[0112] The basic unit of the downlink control channel, namely the REG (503) shown in FIG. 5, may include both the REs to which the DCI is mapped and the DMRS (505), which is a reference signal for decoding, to which the area is mapped. As shown in FIG. 5, three DMRS (505) may be transmitted within one REG (503). The number of CCEs required to transmit the PDCCH may be 1, 2, 4, 8, or 16 depending on the Aggregation Level (AL), and different numbers of CCEs may be used to implement link adaptation of the downlink control channel. For example, when AL=L, one downlink control channel may be transmitted through L CCEs. The terminal must detect the signal without knowing information about the downlink control channel, and a search space representing a set of CCEs is defined for blind decoding. A search space is a set of downlink control channel candidates consisting of CCEs that a terminal must attempt to decode at a given aggregation level, and since there are various aggregation levels that form a group of 1, 2, 4, 8, or 16 CCEs, a terminal may have multiple search spaces. A search space set can be defined as a set of search spaces at all configured aggregation levels.

[0113] Search spaces can be classified into common search spaces and UE-specific search spaces. A certain group of terminals or all terminals may examine the common search space of the PDCCH to receive cell-common control information, such as dynamic scheduling or paging messages regarding system information. For example, PDSCH scheduling allocation information for the transmission of SIBs containing cell operator information can be received by examining the common search space of the PDCCH. In the case of the common search space, since a certain group of terminals or all terminals must receive the PDCCH, it can be defined as a pre-arranged set of CCEs. Scheduling allocation information for a UE-specific PDSCH or PUSCH can be received by examining the UE-specific search space of the PDCCH. The UE-specific search space can be defined specifically as a function of the terminal's identity and various system parameters.

[0114] In 5G, parameters for the search space for a PDCCH can be configured from the base station to the terminal via higher-layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station may configure the terminal the number of PDCCH candidates at each aggregation level L, the monitoring period for the search space, the occasion for monitoring in slot-symbol units for the search space, the search space type (common search space or terminal-specific search space), the combination of DCI format and RNTI to be monitored in the search space, and the control domain index to be monitored in the search space. For example, the information in Table 9 may be included. Of course, it is not limited to the following examples.

[0115] [Table 9]

[0116]

[0117]

[0118] According to the configuration information, the base station may set one or multiple sets of search spaces for the terminal. According to some embodiments, the base station may set search space set 1 and search space set 2 for the terminal, and may set DCI format A scrambled with X-RNTI in search space set 1 to be monitored in a common search space, and may set DCI format B scrambled with Y-RNTI in search space set 2 to be monitored in a terminal-specific search space.

[0119] According to the configuration information, one or more sets of search spaces may exist in a common search space or a terminal-specific search space. For example, Search Space Set #1 and Search Space Set #2 may be configured as a common search space, and Search Space Set #3 and Search Space Set #4 may be configured as a terminal-specific search space.

[0120] In the common search space, the following combinations of DCI formats and RNTI can be monitored. Of course, they may not be limited to the examples below.

[0121] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI

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

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

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

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

[0126] In terminal-specific search spaces, a combination of DCI format and RNTI can be monitored. Of course, it is not limited to the examples below.

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

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

[0129] The specified RNTIs may follow their definitions and uses.

[0130] C-RNTI (Cell RNTI): Used for terminal-specific PDSCH scheduling

[0131] TC-RNTI (Temporary Cell RNTI): Used for terminal-specific PDSCH scheduling

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

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

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

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

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

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

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

[0139] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to instruct power regulation commands to the SRS

[0140] The aforementioned DCI formats may follow the definitions in Table 10 below. Of course, they are not limited to the examples below.

[0141] [Table 10]

[0142]

[0143] In 5G, the search space of aggregation level L in the control domain p and search space set s can be expressed as Equation 1 below.

[0144] [Mathematical Formula 1]

[0145]

[0146]

[0147] In a 5G communication system, as multiple sets of search spaces can be configured with different parameters (e.g., the parameters in Table 10), the set of search space sets monitored by the terminal at each point in time may vary. For example, if search space set #1 is configured with an X-slot period and search space set #2 is configured with a Y-slot period and X and Y are different, the terminal may monitor both search space set #1 and search space set #2 in a specific slot, and may monitor either search space set #1 or search space set #2 in a specific slot.

[0148] FIG. 6 is a diagram illustrating a method for transmitting and receiving data in consideration of a downlink data channel and rate matching resources between a base station and a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0149] FIG. 6 illustrates a downlink data channel (PDSCH, 601) and a rate matching resource (602). A base station may set one or more rate matching resources (602) to a terminal through upper layer signaling (e.g., RRC signaling). The rate matching resource (602) setting information may include time-axis resource allocation information (603), frequency-axis resource allocation information (604), and period information (605). In the following, the bitmap corresponding to the frequency-axis resource allocation information (604) may be named the “first bitmap,” the bitmap corresponding to the time-axis resource allocation information (603) the “second bitmap,” and the bitmap corresponding to the period information (605) the “third bitmap.” If all or part of the time and frequency resources of a scheduled data channel (601) overlap with a set rate matching resource (602), the base station can transmit the data channel (601) by rate matching it in the rate matching resource (602) portion, and the terminal can perform reception and decoding after assuming that the data channel (601) is rate matched in the rate matching resource (602) portion.

[0150] The base station can dynamically notify the terminal via DCI whether to rate match a data channel in the above-mentioned rate matching resource portion through additional settings (corresponding to the “rate matching indicator” within the aforementioned DCI format). Specifically, the base station can select some of the above-mentioned rate matching resources and group them into rate matching resource groups, and can indicate to the terminal via DCI using a bitmap method whether to rate match a data channel for each rate matching resource group. For example, if four rate matching resources, RMR#1, RMR#2, RMR#3, and RMR#4, are set, the base station can set RMG#1={RMR#1, RMR#2} and RMG#2={RMR#3, RMR#4} as rate matching groups, and can indicate to the terminal via a bitmap whether to rate match in RMG#1 and RMG#2, respectively, using 2 bits within the DCI field. For example, you can indicate “1” when rate matching is required and “0” when rate matching is not required.

[0151] In 5G, granularity of “RB symbol level” and “RE level” can be supported by setting the aforementioned rate matching resources to the terminal. More specifically, the following setting method can be followed.

[0152] <RB 심볼 레벨>

[0153] The terminal can receive up to four RateMatchPatterns as upper layer signaling for each bandwidth portion, and one RateMatchPattern may include the following contents.

[0154] As a Reserved Resource within the bandwidth portion, a resource may be included in which the time and frequency resource domains of the said Reserved Resource are set as a combination of an RB level bitmap and a symbol level bitmap along the frequency axis. The said Reserved Resource may span across one or two slots. A time domain pattern (periodicityAndPattern) in which the time and frequency domains composed of each RB level and symbol level bitmap pair are repeated may be additionally set.

[0155] It may include time and frequency domain resource areas set as control resource sets within the bandwidth portion, and resource areas corresponding to time domain patterns set as search space settings where the resource areas are repeated.

[0156] <RE 레벨>

[0157] The terminal can receive the following settings through upper-layer signaling.

[0158] Configuration information for an RE corresponding to an LTE CRS (Cell-specific Reference Signal or Common Reference Signal) pattern (lte-CRS-ToMatchAround) may include the number of ports of the LTE CRS (nrofCRS-Ports) and the LTE-CRS-vshift(s) value (v-shift), information on the location of the LTE carrier's center subcarrier (carrierFreqDL) from a reference frequency point (e.g., reference point A), information on the LTE carrier's bandwidth (carrierBandwidthDL), and subframe configuration information corresponding to a Multiast-broadcast single-frequency network (mbsfn-SubframConfigList). Based on the aforementioned information, the terminal can determine the location of the CRS within an NR slot corresponding to an LTE subframe.

[0159] It may include configuration information for resource sets corresponding to one or more ZP (Zero Power) CSI-RS within the bandwidth portion.

[0160] [PDSCH: Regarding Frequency Resource Allocation]

[0161] FIG. 7 is a diagram illustrating an example of frequency axis resource allocation of a physical downlink shared channel (PDSCH) in a wireless communication system according to one embodiment of the present disclosure.

[0162] Referring to FIG. 7, this is a diagram illustrating three frequency axis resource allocation methods that can be configured through an upper layer in an NR wireless communication system: type 0 (700), type 1 (705), and dynamic switch (710).

[0163] Referring to FIG. 7, if a terminal is configured to use only resource type 0 through upper layer signaling (700), some downlink control information (DCI) that assigns PDSCH to the terminal may include a bitmap consisting of NRBG bits. The conditions for this may be explained later. In this case, NRBG refers to the number of RBGs (resource block groups) determined as shown in [Table 11] below according to the BWP size assigned by the BWP indicator and the upper layer parameter rbg-Size, and data can be transmitted to the RBG indicated as 1 by the bitmap.

[0164] [Table 11]

[0165]

[0166] If the terminal is configured to use only resource type 1 through upper layer signaling (705), some DCIs that assign PDSCH to the terminal are It may include frequency axis resource allocation information consisting of bits. The conditions for this will be explained later. The base station may set the starting VRB (720) and the length (725) of the frequency axis resources continuously allocated therefrom, as described above.

[0167] If the terminal is configured to use both resource type 0 and resource type 1 through upper layer signaling (710), some DCIs that allocate PDSCH to the terminal may include frequency axis resource allocation information consisting of bits of the larger value (7-35) of the payload (715) for setting resource type 0 and the payload (720, 725) for setting resource type 1. The conditions for this will be explained later. In this case, one bit may be added to the beginning part (MSB) of the frequency axis resource allocation information within the DCI, and if the added bit has a value of '0', it indicates that resource type 0 is used, and if it has a value of '1', it indicates that resource type 1 is used.

[0168] [PDSCH / PUSCH: Time Resource Allocation]

[0169] The following describes a time-domain resource allocation method for data channels in next-generation mobile communication systems (5G or NR systems).

[0170] The base station may set a table for time-domain resource allocation information for the Physical Downlink Shared Channel (PDSCH) and the Physical Uplink Shared Channel (PUSCH) for the terminal using upper-layer signaling (e.g., RRC signaling). For PDSCH, a table consisting of a maximum of maxNrofDL-Allocations = 16 entries may be set, and for PUSCH, a table consisting of a maximum of maxNrofUL-Allocations = 16 entries may be set. In one embodiment, the time domain resource allocation information may include PDCCH-to-PDSCH slot timing (corresponding to a slot-unit time interval between the time when the PDCCH is received and the time when the PDSCH scheduled by the received PDCCH is transmitted, denoted as K0), PDCCH-to-PUSCH slot timing (corresponding to a slot-unit time interval between the time when the PDCCH is received and the time when the PUSCH scheduled by the received PDCCH is transmitted, denoted as K2), information regarding the position and length of the starting symbol for which the PDSCH or PUSCH is scheduled within the slot, and the mapping type of the PDSCH or PUSCH. For example, information such as [Table 12] or [Table 13] below may be transmitted from the base station to the terminal. Of course, it may not be limited to the above examples.

[0171] [Table 12]

[0172]

[0173] [Table 13]

[0174]

[0175] The base station may notify the terminal of one of the entries in the table for the time domain resource allocation information described above via L1 signaling (e.g., DCI) (e.g., indicated by the 'time domain resource allocation' field within the DCI). The terminal may obtain time domain resource allocation information for PDSCH or PUSCH based on the DCI received from the base station.

[0176] FIG. 8 is a diagram illustrating an example of time axis resource allocation of PDSCH in a wireless communication system according to one embodiment of the present disclosure.

[0177] Referring to FIG. 8, the base station uses the upper layer to set the subcarrier spacing (SCS) (μ) of the data channel and control channel. PDSCH , μ PDCCH The time axis position of the PDSCH resource can be indicated according to the scheduling offset (K0) value, and the OFDM symbol start position (8-00) and length (8-05) within a slot that are dynamically indicated through DCI.

[0178] FIG. 9 is a diagram illustrating an example of time-axis resource allocation according to the subcarrier interval of a data channel and a control channel in a wireless communication system according to one embodiment of the present disclosure.

[0179] Referring to FIG. 9, when the subcarrier spacing of the data channel and the control channel is the same (900, μ PDSCH = μ PDCCH), since the slot numbers for data and control are the same, the base station and the terminal can generate a scheduling offset by aligning with a predetermined slot offset K0. On the other hand, when the subcarrier spacing of the data channel and the control channel is different (9-05, μ PDSCH ≠ μ PDCCH Since the slot numbers for data and control are different, the base station and the terminal can generate a scheduling offset based on the subcarrier interval of the PDCCH and in accordance with a predetermined slot offset K0.

[0180] [PUSCH: Regarding transmission method]

[0181] Next, the scheduling method for PUSCH transfers can be described. PUSCH transfers can be dynamically scheduled by UL grants within the DCI, or operated by configured grant Type 1 or Type 2. Dynamic scheduling instructions for PUSCH transfers can be in DCI format 0_0 or 0_1.

[0182] The terminal's Configured grant Type 1 PUSCH transmission can be semi-statically configured by receiving configuredGrantConfig, which includes rrc-ConfiguredUplinkGrant of [Table 14], through upper-layer signaling, without receiving UL grants within DCI. The terminal's Configured grant Type 2 PUSCH transmission can be semi-continuously scheduled by UL grants within DCI after receiving configuredGrantConfig, which does not include rrc-ConfiguredUplinkGrant of [Table 14], through upper-layer signaling. When the PUSCH transmission is operated by the configured grant, the parameters applied to the PUSCH transmission can be applied through configuredGrantConfig, the upper-layer signaling of [Table 14], except for dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, and scaling of UCI-OnPUSCH, which are provided by pusch-Config of [Table 15], the upper-layer signaling. If the terminal is provided with transformPrecoder in configuredGrantConfig, which is the upper signaling of [Table 14], the terminal can apply tp-pi2BPSK in pusch-Config of [Table 15] to PUSCH transmissions operated by the configured grant.

[0183] [Table 14]

[0184]

[0185]

[0186] Next, the PUSCH transmission method is described. The DMRS antenna port for PUSCH transmission can be the same as the antenna port for SRS transmission. PUSCH transmission can follow a codebook-based transmission method and a non-codebook-based transmission method, respectively, depending on whether the value of txConfig in pusch-Config in [Table 15], the upper signaling, is 'codebook' or 'nonCodebook'.

[0187] As described above, PUSCH transmissions can be dynamically scheduled via DCI format 0_0 or 0_1 and semi-statically configured by a configured grant. If a terminal is instructed to schedule a PUSCH transmission via DCI format 0_0, the terminal may perform beam configuration for the PUSCH transmission using the pucch-spatialRelationInfoID corresponding to the terminal-specific PUCCH resource corresponding to the minimum ID within an active uplink BWP in the serving cell, whereby the PUSCH transmission may be based on a single antenna port. Within a BWP where a PUCCH resource containing pucch-spatialRelationInfo is not configured, the terminal may not expect scheduling for the PUSCH transmission via DCI format 0_0. If the terminal has not configured txConfig within pusch-Config of [Table 15], the terminal may not expect to be scheduled via DCI format 0_1.

[0188] [Table 15]

[0189]

[0190] Next, codebook-based PUSCH transmission can be described. Codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1 and can operate semi-statically via a configured grant. When codebook-based PUSCH is dynamically scheduled via DCI format 0_1 ​​or semi-statically configured via a configured grant, the terminal can determine a precoder for PUSCH transmission based on the SRS Resource Indicator (SRI), Transmission Precoding Matrix Indicator (TPMI), and the transmission rank (number of PUSCH transmission layers).

[0191] In this case, the SRI can be provided through the SRS resource indicator field within the DCI or configured through the higher-level signaling srs-ResourceIndicator. When transmitting a codebook-based PUSCH to the terminal, at least one SRS resource may be configured, and up to two may be configured. When the terminal receives an SRI through the DCI, the SRS resource indicated by the SRI received through the DCI may refer to the SRS resource corresponding to the SRI among the SRS resources transmitted prior to the PDCCH containing the SRI received through the DCI. Additionally, the TPMI and transmission rank may be provided through the precoding information and number of layers field within the DCI or configured through the higher-level signaling precodingAndNumberOfLayers. The TPMI can be used to indicate the precoder applied to the PUSCH transmission. If one SRS resource is configured in the terminal, the TPMI can be used to indicate the precoder to be applied from the configured single SRS resource. If multiple SRS resources are configured on the terminal, TPMI can be used to specify the precoder to be applied to the SRS resource indicated by SRI.

[0192] The precoder to be used for PUSCH transmission may be selected from an uplink codebook having the same number of antenna ports as the nrofSRS-Ports value in the upper-layer signaling SRS-Config. In codebook-based PUSCH transmission, the terminal may determine the codebook subset based on TPMI and the codebookSubset in the upper-layer signaling pusch-Config. The codebookSubset in the upper-layer signaling pusch-Config may be set to 'fullyAndPartialAndNonCoherent', 'partialAndNonCoherent', or 'nonCoherent' based on the UE capability reported by the terminal to the base station. If the terminal reports 'partialAndNonCoherent' as the UE capability, the terminal may not expect the value of the upper-layer signaling codebookSubset to be set to 'fullyAndPartialAndNonCoherent'. Additionally, if the terminal reports 'nonCoherent' as a UE capability, the terminal may not expect the value of the upper layer signaling codebookSubset to be set to 'fullyAndPartialAndNonCoherent' or 'partialAndNonCoherent'. If nrofSRS-Ports in the upper layer signaling SRS-ResourceSet points to two SRS antenna ports, the terminal may not expect the value of the upper layer signaling codebookSubset to be set to 'partialAndNonCoherent'.

[0193] One SRS resource set may be configured in the terminal with the value of 'usage' in the upper layer signaling SRS-ResourceSet set set to 'codebook', and one SRS resource within the configured SRS resource set may be indicated via SRI. If multiple SRS resources are configured within the SRS resource set in which the value of 'usage' in the upper layer signaling SRS-ResourceSet set to 'codebook', the terminal can expect the value of nrofSRS-Ports in the upper layer signaling SRS-Resource to be set to the same value for all SRS resources.

[0194] A terminal may transmit one or more SRS resources included in an SRS resource set in which the value of usage is set to 'codebook' according to upper layer signaling to a base station, and the base station may select one of the SRS resources transmitted by the terminal and instruct the terminal to perform PUSCH transmission using the transmit beam information of the selected SRS resource. In this case, in codebook-based PUSCH transmission, SRI is used as information to select the index of one SRS resource and may be included in the DCI. Additionally, the base station may include information in the DCI that instructs the TPMI and rank to be used by the terminal for PUSCH transmission. The terminal may perform PUSCH transmission by using the SRS resource instructed by the SRI, applying the instructed rank based on the transmit beam of the SRS resource instructed by the SRI, and the precoder instructed by the TPMI.

[0195] Next, non-codebook-based PUSCH transmission is described. Non-codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1 and can operate semi-statically via configured grant. If at least one SRS resource is configured within an SRS resource set in which the value of usage within the upper layer signaling SRS-ResourceSet is set to 'nonCodebook', non-codebook-based PUSCH transmission can be scheduled to the terminal via DCI format 0_1.

[0196] For an SRS resource set in which the value of usage within the upper layer signaling SRS-ResourceSet is set to 'nonCodebook', one NZP CSI-RS resource (non-zero power CSI-RS) connected to the terminal may be configured. The terminal can perform calculations for a precoder for SRS transmission by measuring the NZP CSI-RS resource connected to the SRS resource set. If the difference between the last received symbol of the aperiodic NZP CSI-RS resource connected to the SRS resource set and the first symbol of the aperiodic SRS transmission at the terminal is less than 42 symbols, the terminal may not expect the information for the precoder for SRS transmission to be updated.

[0197] If the value of resourceType in the upper layer signaling SRS-ResourceSet is set to 'aperiodic', the connected NZP CSI-RS may be indicated by the SRS request field in DCI format 0_1 ​​or 1_1. In this case, if the connected NZP CSI-RS resource is a non-periodic NZP CSI-RS resource, the existence of the connected NZP CSI-RS may be indicated if the value of the SRS request field in DCI format 0_1 ​​or 1_1 is not '00'. In this case, the DCI may not indicate cross-carrier or cross-BWP scheduling. Additionally, if the value of the SRS request indicates the existence of the NZP CSI-RS, the NZP CSI-RS may be located in the slot where the PDCCH containing the SRS request field was transmitted. In this case, the TCI states set on the scheduled subcarrier may not be set to QCL-TypeD.

[0198] If a periodic or semi-persistent SRS resource set is established, the associated NZP CSI-RS can be indicated via the associated CSI-RS within the upper-layer signaling SRS-ResourceSet. For non-codebook-based transmissions, the terminal may not expect the upper-layer signaling spatialRelationInfo for the SRS resource and the associated CSI-RS within the upper-layer signaling SRS-ResourceSet to be established together.

[0199] When multiple SRS resources are configured in a terminal, the terminal can determine the precoder and transmission rank to be applied for PUSCH transmission based on the SRI indicated by the base station. In this case, the SRI may be indicated via a field SRS resource indicator within the DCI or configured via the srs-ResourceIndicator, which is a higher-layer signaling. Similar to the codebook-based PUSCH transmission described above, when the terminal receives an SRI via the DCI, the SRS resource indicated by the SRI received via the DCI may refer to an SRS resource corresponding to the SRI among the SRS resources transmitted prior to the PDCCH containing the SRI received via the DCI. The terminal may use one or multiple SRS resources for SRS transmission, and the maximum number of SRS resources that can be transmitted simultaneously in the same symbol within a single SRS resource set and the maximum number of SRS resources may be determined by the UE capability reported by the terminal to the base station. In this case, SRS resources transmitted simultaneously by the terminal may occupy the same RB. The terminal can configure one SRS port for each SRS resource. Only one SRS resource set can be configured where the value of usage in the upper layer signaling SRS-ResourceSet is set to 'nonCodebook', and up to four SRS resources can be configured for non-codebook based PUSCH transmission.

[0200] A base station can transmit one NZP-CSI-RS connected to an SRS resource set to a terminal, and the terminal can calculate a precoder to be used when transmitting one or more SRS resources within the SRS resource set based on the results measured upon receiving the NZP-CSI-RS. The terminal can apply the calculated precoder described above when transmitting one or more SRS resources within an SRS resource set where usage is set to 'nonCodebook' to the base station, and the base station can select one or more SRS resources from among the received one or more SRS resources. In this case, in non-codebook-based PUSCH transmission, the SRI may represent an index capable of expressing a combination of one or more SRS resources, and the SRI may be included within the DCI. In this case, the number of SRS resources indicated by the SRI transmitted by the base station may be the number of transmission layers of the PUSCH, and the terminal can transmit the PUSCH by applying the precoder applied for SRS resource transmission to each layer.

[0201] [CA / DC Related]

[0202] FIG. 10 is a diagram illustrating the wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation, dual connectivity situation in a wireless communication system according to one embodiment of the present disclosure.

[0203] Referring to FIG. 10, the wireless protocol of the next-generation mobile communication system may include NR SDAP (Service Data Adaptation Protocol 1025, 1070), NR PDCP (Packet Data Convergence Protocol 1030, 1065), NR RLC (Radio Link Control 1035, 1060), and NR MAC (Medium Access Control 1040, 1055) at the terminal and the NR base station, respectively. Of course, it is not limited to the examples and may include more or fewer layers.

[0204] The main functions of NR SDAP (1025, 1070) may include some of the following functions. Of course, it is not limited to the examples below.

[0205] - User data transfer function (transfer of user plane data)

[0206] - Mapping function between a QoS flow and a DRB for both DL and UL for uplink and downlink

[0207] - Marking QoS flow ID for uplink and downlink (marking QoS flow ID in both DL and UL packets)

[0208] - Function to map reflective QoS flow to data bearers for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

[0209] For the aforementioned SDAP layer device, whether to use the header of the SDAP layer device or to use the functions of the SDAP layer device can be configured via an RRC message to the terminal for each PDCP layer device, for each bearer, or for each logical channel. If the SDAP header is configured, the base station may instruct the terminal to update or reset the mapping information for the uplink and downlink QoS flows and data bearers using the NAS reflective QoS and AS reflective QoS 1-bit indicators of the SDAP header. The SDAP header may include QoS flow ID information indicating QoS. The QoS information may be used for at least one of data processing priority or scheduling information to support seamless service.

[0210] The main functions of NR PDCP (S30, S65) may include some of the following functions. The main functions of NR PDCP (1030, 1065) may include some of the following functions. Of course, they are not limited to the examples below.

[0211] - Header compression and decompression features (ROHC only)

[0212] - User data transfer function (Transfer of user data)

[0213] - Sequential delivery function (In-sequence delivery of upper layer PDUs)

[0214] - Out-of-sequence delivery of upper layer PDUs

[0215] - Reordering function (PDCP PDU reordering for reception)

[0216] - Duplicate detection function (Duplicate detection of lower layer SDUs)

[0217] - Retransmission of PDCP SDUs

[0218] - Encryption and decryption functions (Ciphering and deciphering)

[0219] - Timer-based SDU discard in uplink.

[0220] In the functions described above, the reordering function of the NR PDCP device refers to a function that reorders PDCP PDUs received from a lower layer in order based on the PDCP SN (sequence number), and may include a function that transmits data to an upper layer in the reordered order. Alternatively, the reordering function of the NR PDCP device may include a function that transmits immediately without considering the order, a function that records lost PDCP PDUs by reordering, a function that transmits a status report on lost PDCP PDUs to the transmitting side, and a function that requests retransmission of lost PDCP PDUs.

[0221] The main functions of NR RLC(1035, 1060) may include some of the following functions. Of course, they are not limited to the examples below.

[0222] - Data transfer function (Transfer of upper layer PDUs)

[0223] - Sequential delivery function (In-sequence delivery of upper layer PDUs)

[0224] - Out-of-sequence delivery of upper layer PDUs

[0225] - ARQ function (Error Correction through ARQ)

[0226] - Concatenation, segmentation, and reassembly functions of RLC SDUs

[0227] - Re-segmentation function (Re-segmentation of RLC data PDUs)

[0228] - - Reordering function (Reordering of RLC data PDUs)

[0229] - Duplicate detection

[0230] - Error detection function (Protocol error detection)

[0231] - RLC SDU discard function

[0232] RLC re-establishment function

[0233] In the functions described above, the in-sequence delivery function of the NR RLC device may mean a function of delivering RLC SDUs received from a lower layer to an upper layer in order. The in-sequence delivery function of the NR RLC device may include a function of reassembling and delivering multiple divided RLC SDUs when a single RLC SDU is originally received divided into multiple RLC SDUs, a function of rearranging the received RLC PDUs based on an RLC SN (sequence number) or PDCP SN (sequence number), a function of recording lost RLC PDUs by rearranging the order, a function of transmitting a status report on the lost RLC PDUs to the transmitting side, and a function of requesting retransmission of the lost RLC PDUs. The in-sequence delivery function of the NR RLC device may include a function to deliver only the RLC SDUs prior to the lost RLC SDU in order to the upper layer if there is a lost RLC SDU, or a function to deliver all RLC SDUs received before the timer started in order to the upper layer if a predetermined timer has expired even if there is a lost RLC SDU. Alternatively, the in-sequence delivery function of the NR RLC device may include a function to deliver all RLC SDUs received up to the present in order to the upper layer if a predetermined timer has expired even if there is a lost RLC SDU.Additionally, RLC PDUs may be processed in the order they are received (e.g., regardless of the order of sequence numbers or the order of arrival) and delivered to the PDCP device out of order (out-of-sequence delivery). In the case of segments, segments stored in a buffer or to be received later may be received, reconstructed into a single complete RLC PDU, processed, and delivered to the PDCP device. The NR RLC layer may not include a concatenation function, and the concatenation function may be performed by the NR MAC layer or replaced by the multiplexing function of the NR MAC layer.

[0234] The out-of-sequence delivery function of an NR RLC device refers to the function of delivering RLC SDUs received from a lower layer directly to an upper layer regardless of order. In cases where a single RLC SDU is received divided into multiple RLC SDUs, it may include the function of reassembling and delivering the divided multiple RLC SDUs, and may also include the function of storing the RLC SN or PDCP SN of the received RLC PDUs and sorting the order to record the lost RLC PDUs.

[0235] The NR MAC (1040, 1055) can be connected to multiple NR RLC layer devices configured in a terminal, and the main functions of the NR MAC may include some of the following functions. Of course, it is not limited to the examples below.

[0236] -- Mapping function (Mapping between logical channels and transport channels)

[0237] -- Multiplexing and Demultiplexing Functions (Multiplexing / demultiplexing of MAC SDUs)

[0238] -- Scheduling information reporting function

[0239] -- HARQ function (Error correction through HARQ)

[0240] -- Priority handling between logical channels of one UE

[0241] -- Priority handling between UEs by means of dynamic scheduling

[0242] -- MBMS service identification

[0243] -- Transport format selection function

[0244] -- Padding

[0245] The NR PHY layer (1045, 1050) can perform the operation of channel coding and modulating upper layer data, creating OFDM symbols and transmitting them over a wireless channel, or demodulating OFDM symbols received through a wireless channel and channel decoding them to transmit them to an upper layer. Of course, it is not limited to the above examples.

[0246] The detailed structure of a wireless protocol can vary depending on the carrier (or cell) operation method. In one embodiment, when a base station transmits data to a terminal based on a single carrier (or cell), the base station and the terminal may use a protocol structure having a single structure for each layer, such as 1000. On the other hand, when a base station transmits data to a terminal based on Carrier Aggregation (CA) using multiple carriers at a single Transmission and Reception Point (TRP), the base station and the terminal may use a protocol structure that has a single structure up to the RLC but multiplexes the Physical Layer (PHY layer) through the MAC layer, such as 1010. In one embodiment, when a base station transmits data to a terminal based on Dual Connectivity (DC) using multiple carriers at multiple TRPs, the base station and the terminal may use a protocol structure that has a single structure up to the RLC but multiplexes the PHY layer through the MAC layer, such as 1020.

[0247] Referring to the descriptions regarding PDCCH and beam configuration described above, PDCCH repeated transmission is not currently supported in Rel-15 and Rel-16 NR, making it difficult to achieve the required reliability in scenarios requiring high reliability, such as URLLC. The present disclosure provides a method for PDCCH repeated transmission through multiple transmission points (TRP). According to the present disclosure, the PDCCH reception reliability of a terminal can be improved. Specific methods are described in detail in the following examples.

[0248] Embodiments of the present disclosure may be described in detail below with reference to the accompanying drawings. An embodiment of the present disclosure may be applied to systems such as FDD (Frequency Division Duplex), TDD (Time Division Duplex), and XDD (Cross Division Duplex), for example, but is not limited thereto. In the present disclosure below, upper signaling (or upper layer signaling) may be a signal transmission method or a signal transmitted from a base station to a terminal using a physical layer downlink data channel, or from a terminal to a base station using a physical layer uplink data channel. For example, upper signaling (or upper layer signaling) may be referred to as RRC signaling, PDCP signaling, or a MAC (medium access control) control element (MAC CE), but is not limited thereto.

[0249] In determining whether cooperative communication is applied in the present disclosure, the terminal may use various methods, such as the PDCCH(s) assigning the PDSCH to which cooperative communication is applied having a specific format, or the PDCCH(s) assigning the PDSCH to which cooperative communication is applied including a specific indicator indicating whether cooperative communication is applied, or the PDCCH(s) assigning the PDSCH to which cooperative communication is applied being scrambled with a specific RNTI, or assuming the application of cooperative communication in a specific section indicated to an upper layer, and may not be limited thereto. For convenience of explanation below, the reception of a PDSCH to which cooperative communication is applied by the terminal based on conditions similar to those above may be referred to as an NC-JT (Non-Coherent Joint Transmission) case. That is, in the present disclosure, an NC-JT case includes the reception of a PDSCH to which cooperative communication is applied, and whether cooperative communication is applied may be identified according to at least one of the conditions / methods described above or a combination of at least one or more.

[0250] In the following disclosure, the statement that priority between A and B can be determined may be referred to in various ways, such as selecting the one with higher priority according to a predetermined priority rule and performing the corresponding action, or omitting or dropping the action for the one with lower priority.

[0251] In the following disclosure, the examples are described through a plurality of embodiments, but these are not independent, and one or more embodiments may be applied simultaneously or in combination.

[0252] In describing the present disclosure below, the term "upper layer signaling" may refer to a signaling corresponding to at least one or a combination of one or more of the following signalings. Of course, it is not limited to the following examples.

[0253] - MIB (Master Information Block)

[0254] - SIB (System Information Block) or SIB

[0255] - RRC (Radio Resource Control)

[0256] - MAC (Medium Access Control) CE (Control Element)

[0257] In addition, L1 signaling may be a signaling corresponding to at least one or a combination of at least one of the following physical layer channels or signaling methods using signaling. Of course, it is not limited to the following examples.

[0258] - PDCCH (Physical Downlink Control Channel)

[0259] - DCI (Downlink Control Information)

[0260] - Terminal-specific (UE-specific) DCI

[0261] - Group common DCI

[0262] - Common DCI

[0263] - Scheduling DCI (e.g., DCI used for the purpose of scheduling downlink or uplink data)

[0264] - Non-scheduling DCI (e.g., DCI not intended for scheduling downlink or uplink data)

[0265] - PUCCH (Physical Uplink Control Channel)

[0266] - UCI (Uplink Control Information)

[0267] In the following disclosure, determining the priority between A and B may be referred to in various ways, such as selecting the one with the higher priority according to a predetermined priority rule and performing the corresponding action, or omitting or dropping the action for the one with the lower priority.

[0268] In the following disclosure, the examples are described through a plurality of embodiments, but these are not independent, and one or more embodiments may be applied simultaneously or in combination.

[0269] [Random Access Procedure]

[0270] In a communication system, a terminal can establish a wireless link with a network through a random access procedure based on network synchronization and system information acquired during the cell search process. Random access may utilize contention-based or contention-free methods. A contention-based random access method may be used when the terminal performs cell selection and re-selection during the initial connection phase of a cell, for example, when moving from the RRC_IDLE state to the RRC_CONNECTED state. Contention-free random access may be used to reset uplink synchronization when downlink data arrives, in the case of a handover, or for location measurement.

[0271] FIG. 11 is a diagram illustrating a random access procedure in a wireless communication system according to an embodiment of the present disclosure.

[0272] Referring to FIG. 11, a contention-based random access procedure is illustrated as an example. Additionally, although not illustrated, a base station may transmit a synchronization signal block as described in the embodiments above. In this case, the base station may periodically transmit the synchronization signal block using beam sweeping. For example, the base station may transmit a synchronization signal block containing PSS / SSS (synchronization signal) and PBCH (broadcast channel) signals using up to 64 different beams for 5 ms, and multiple synchronization signal blocks may be transmitted using different beams. The terminal may detect (select) a synchronization signal block having an optimal beam direction (e.g., a beam direction where the received signal strength is strongest or greater than a predetermined threshold) and transmit a preamble to the base station using the PRACH (physical random access channel) resource associated with the detected synchronization signal block. For example, as a first step (1101) of the random access procedure, the terminal may transmit a random access preamble (or message 1 (msg1)) to the base station. Upon receiving the random access preamble, the base station may measure the transmission delay value between the terminal and the base station and synchronize the uplink. Specifically, the terminal may transmit a random access preamble randomly selected from a set of random access preambles given in advance by system information. The initial transmission power of the random access preamble may be determined based on the path loss between the base station and the terminal measured by the terminal. Additionally, the terminal may determine the transmission beam direction (or transmission beam or beam) of the random access preamble based on the synchronization signal block received from the base station and transmit the random access preamble by applying the determined transmission beam direction.

[0273] In the second step (1102), the base station may transmit a response to the detected random access attempt (random access response, RAR, or message 2 (message 2, msg2)) to the terminal. The base station may transmit an uplink transmission timing control command to the terminal based on the transmission delay value measured from the random access preamble received in the first step. Additionally, the base station may transmit uplink resource and power control commands to be used by the terminal as scheduling information. The scheduling information may include control information for the terminal's uplink transmission beam. The RAR is transmitted via PDSCH and may include at least one of the following information. Of course, it is not limited to the examples below.

[0274] -- Random access preamble sequence index detected by the network (or base station)

[0275] -- TC-RNTI(temporary cell radio network temporary identifier)

[0276] -- Uplink scheduling grant

[0277] -- Timing advance value

[0278] If the terminal does not receive RAR, which is scheduling information for message 3, from the base station for a predetermined period of time in the second step (1102), the first step (1101) can be performed again. If the first step is performed again, the terminal increases the transmission power of the random access preamble by a predetermined step (this is called power ramping), thereby increasing the probability of the base station receiving the random access preamble.

[0279] In the third step (1103), the terminal may transmit uplink information (scheduled transmission, or message 3 (msg3)) containing its terminal identifier (UE contention resolution identity, or if the terminal already has a valid terminal identifier (C-RNTI) within the cell before the start of the random access procedure, that valid terminal identifier) ​​to the base station via the physical uplink shared channel (PUSCH) using the uplink resources allocated in the second step (1102). PUSCH may be referred to as message 3 PUSCH (msg3 PUSCH). The transmission timing of the uplink data channel for transmitting message 3 may follow the uplink transmission timing control command received from the base station in the second step (1102). Additionally, the transmission power of the uplink data channel for transmitting message 3 may be determined by considering the power control command received from the base station in the second step (1102) and the power ramping value of the random access preamble. Message The uplink data channel for transmitting 3 may be the first uplink data signal that the terminal transmits to the base station after the random access preamble transmission.

[0280] Finally, in step 4 (1104), if the base station determines that the terminal has performed random access without collision with other terminals, it may transmit a message (contention resolution message: CR message, or message 4 (msg4)) containing the identifier of the terminal that transmitted uplink data in step 3 (1103) to the terminal. In this regard, if multiple terminals receive the same TC-RNTI in step 2 (1102), the multiple terminals that received the same TC-RNTI each transmit to the base station in step 3 (1103) their own terminal identifier (UE contention resolution identity) included in message 3, and the base station may transmit message 4 (CR message) containing the terminal identifier of one of the multiple terminals to resolve the contention. When a terminal receives a message 4 (CR message) containing its terminal identifier from the base station in the fourth step (1104) (or transmits a message 3 (message 3) containing a terminal identifier (C-RNTI) in the third step (1103), and receives terminal-specific control information containing a CRC based on the terminal identifier (C-RNTI) via the PDCCH in the fourth step (1104), it can determine that random access has succeeded. Therefore, among multiple terminals that have received the same TC-RNTI from the base station, a terminal that confirms that its terminal identifier is included in message 4 (CR message) can confirm that it has succeeded in the competition. Then, the terminal can transmit a HARQ-ACK / NACK indicating successful reception of message 4 to the base station via the physical uplink control channel (PUCCH).

[0281] If the data transmitted by the terminal in the third step (1103) and the data of another terminal collide with each other, and the base station fails to receive the data signal from the terminal, the base station may not perform further data transmission to the terminal. Accordingly, if the terminal fails to receive the data transmitted from the base station in the fourth step (1104) for a certain period of time, it is determined that the random access procedure has failed, and the process may be restarted from the first step (1101).

[0282] As described above, in the first step (1101) of the random access process, the terminal can transmit a random access preamble onto PRACH. Each cell has 64 available preamble sequences, and depending on the transmission format, 4 long preamble formats and 9 short preamble formats may be used. The terminal generates 64 preamble sequences using a root sequence index and a cyclic shift value signaled as system information, and can randomly select one sequence to use as a preamble.

[0283] A base station may provide a terminal with configuration information for random access resources, such as control information (or configuration information) indicating time-frequency resources that can be used for PRACH, using at least one of SIB, upper layer signaling (RRC (Radio Resource Control) information), or DCI (Downlink Control Information). Frequency resources for PRACH transmission may indicate the starting RB point of transmission to the terminal, and the number of RBs used may be determined according to the preamble format transmitted via PRACH and the applied subcarrier interval. Time resources for PRACH transmission may be provided through a PRACH configuration index (0 to 255), such as a pre-set PRACH setting period, a subframe index containing a PRACH transmission time (PRACH occasion, which may be used interchangeably with transmission time), a start symbol, and the number of PRACH transmission times within a slot, as shown in Table 16 below. The terminal determines the validity of the PRACH transmission timestamps indicated in the PRACH configuration index and determines only the valid PRACH transmission timestamps as PRACH transmission timestamps capable of transmitting a random access preamble. Through the PRACH configuration index, the random access configuration information included in the SIB, and the index of the SSB selected by the terminal, the terminal identifies the time and frequency resources for transmitting the random access preamble and can transmit the selected sequence as a preamble to the base station.

[0284] [Table 16]

[0285]

[0286] A terminal in the RRC IDLE (or RRC INACTIVE or RRC configuration change period) state can monitor the transmission and reception of control information for random access and the DCI format for data transmission and reception during the random access process. This DCI format can be called fallback DCI. Here, the terminal can monitor the fallback DCI in the following cases.

[0287] 1) Before receiving RRC configuration information or

[0288] 2) When RRC configuration information is received but there is no valid RRC configuration information (e.g., when the state changes to RRC IDLE, or when the state changes to RRC INACTIVE, or during an RRC reset period)

[0289] More specifically, the terminal may be configured to monitor multiple DCI formats from the base station. When configured to monitor multiple DCI formats, the Fallback DCI may appear as some of the DCI formats among the multiple DCI formats monitored by the terminal. For example, in an NR system, DCI format 0_0 and DCI format 1_0 may be referred to as fallback DCI. Other DCI formats (e.g., DCI format 0_1 ​​and DCI format 1_1, etc.) may be referred to as non-fallback DCI.

[0290] For reference, the present disclosure is based on an NR system, but the same technology can be applied to communication systems other than NR systems.

[0291] More specifically, if the terminal is configured to monitor multiple DCI formats, the Fallback DCI may be determined based on the type of search space in which the DCI format is configured. For example, a DCI format monitored in a common search space may be a fallback DCI. A DCI format monitored in a user-specific search space may be a non-fallback DCI. Here, some common search spaces (e.g., a type-3 common search space where DCI is monitored according to RRC settings) may be excluded.

[0292] In other words, the fallback DCI used in this disclosure refers to the DCIs that the terminal monitors from the base station regardless of the RRC configuration information set for the terminal.

[0293] FIG. 12 is a diagram illustrating the process of a terminal monitoring fallback DCI in chronological order during an arbitrary connection process in an NR system according to one embodiment of the present disclosure.

[0294] Referring to FIG. 12, the terminal can obtain information regarding the configuration of CORESET0 and Type-0 CSS (common search space) through the SS / PBCH block. Based on the configured CORESET0 and Type-0 CSS, the terminal can monitor DCI format 1_0. Here, the CRC of DCI format 1_0 may be a DCI format scrambled with SI-RNTI. The DCI format 1_0 corresponding to the SI-RNTI may be a DCI that schedules PDSCH including system information block 1 (SIB1).

[0295] The terminal can obtain cell common configuration information from SIB1. The cell common configuration information may include at least one of the cell's TDD configuration information, RACH-related configuration information, and initial BWP configuration. After receiving SIB1, the terminal can perform an arbitrary connection process based on SIB1.

[0296] The terminal can transmit PRACH (msg1) to the base station and monitor DCI format 1_0, which schedules PDSCH including a Random Access Response (RAR) to the PRACH. Here, the CRC of DCI format 1_0 is scrambled with RA-RNTI. Here, the value of RA-RNTI can be determined based on the time, frequency, and carrier type of the PRACH, and the RACH setting (whether it is 2-step or 4-step). Here, the DCI format corresponding to RA-RNTI can be monitored in Type-1 CSS, and Type-1 CSS can be set in SIB1. The RAR may include a UL grant for transmitting msg3. The terminal can transmit msg3 PUSCH to the base station based on the UL grant. The terminal may monitor DCI format 0_0, which indicates whether to retransmit the msg3 PUSCH, or DCI format 1_0, which schedules the Msg4 PDSCH. Here, the CRC of DCI format 0_0 and DCI format 1_0 may be scrambled with TC-RNTI. Here, TC-RNTI may be included in RAR. Here, DCI format 0_0 and DCI format 1_0 associated with TC-RNTI may be monitored in Type-1 CSS. If the terminal receives DCI format 1_0 (corresponding to TC-RNTI) scheduling the Msg4 PDSCH, and the Msg4 PDSCH contains information of the terminal (contention resolution completed), the terminal may transmit a HARQ-ACK to the base station. Subsequently, the terminal may monitor DCI format 0_0 to DCI format 1_0 scrambled with C-RNTI to receive the terminal's RRC configuration information. Here, C-RNTI can be the same value as TC-RNTI.Here, the search space where DCI format 0_0 to DCI format 1_0 is monitored may be Type-0 CSS to Type-1 CSS. When the terminal receives RRC configuration information, the terminal may monitor not only fallback DCI but also non-fallback DCI. Here, non-fallback DCI may be a DCI format determined based on RRC configuration information (e.g., DCI format 0_1 ​​to DCI format 1_1).

[0297] In the example described above, before receiving RRC configuration information, the terminal can monitor 1) a DCI format corresponding to SI-RNTI, 2) a DCI format corresponding to RA-RNTI, 3) a DCI format corresponding to TC-RNTI, and 4) a DCI format corresponding to C-RNTI.

[0298] According to the NR system, the lengths of DCI formats corresponding to different RNTIs can always be the same. That is, the length of DCI format 0_0 corresponding to TC-RNTI and the length of DCI format corresponding to C-RNTI can always be the same. In addition, the lengths of DCI format 1_0 corresponding to SI-RNTI, DCI format 1_0 corresponding to RA-RNTI, DCI format 1_0 corresponding to TC-RNTI, and DCI format 1_0 corresponding to C-RNTI can always be the same. This is because when a terminal monitors DCI, it can perform blind decoding based on the assumption of the same length.

[0299] According to the NR system, the length of the DCI format corresponding to different RNTIs is the same, but the types and lengths of the DCI fields included in the DCI format may differ. For example, Table 17 shows the DCI fields and lengths included in DCI format 1_0 corresponding to C-RNTI, and Table 18 shows the DCI fields and lengths included in DCI format 1_0 corresponding to SI-RNTI.

[0300]

[0301] Blind decoding can be performed based on this.

[0302] Referring to Tables 17 and 18, DCI formats corresponding to different RNTIs may include different DCI fields. For example, DCI format 1_0 corresponding to SI-RNTI may include a 1-bit System information indicator field, but DCI format 1_0 corresponding to C-RNTI may not include the said field. This is because the purpose of the PDSCH scheduled by DCI format 1_0 corresponding to SI-RNTI is different from the purpose of the PDSCH scheduled by DCI format 1_0 corresponding to C-RNTI. For example, the 1-bit System information indicator field included in DCI format 1_0 corresponding to SI-RNTI is an indicator that indicates whether the PDSCH scheduled by DCI format 1_0 corresponding to SI-RNTI includes SIB1 or other SIBs. Therefore, the DCI format 1_0 corresponding to the C-RNTI that is not used for scheduling SIB does not need to include the above 1-bit length System information indicator field.

[0303] As another example, the DCI format 1_0 corresponding to C-RNTI may include a TPC command for scheduled PUCCH field, but the DCI format 1_0 corresponding to SI-RNTI may not include the said field. Here, the TPC command for scheduled PUCCH field is a DCI field that can be used to indicate the transmission power of a PUCCH containing a HARQ-ACK of a PDSCH. However, since there is no corresponding HARQ-ACK and PUCCH in the PDSCH scheduled by the DCI format 1_0 corresponding to SI-RNTI, the said DCI field may not be included in the DCI format 1_0 corresponding to SI-RNTI.

[0304] [Table 17]

[0305]

[0306] [Table 18]

[0307]

[0308] Referring to Tables 17 and 18, the DCI fields included in the DCI format 1_0 corresponding to each RNTI can be fixed.

[0309] For example, DCI format 1_0 corresponding to SI-RNTI may consist of a Frequency domain resource assignment (FDRA) field, a Time domain resource assignment (TDRA) field, a VRB-to-PRB mapping field, a Modulation and coding scheme (MCS) field, a Redundancy version (RV) field, a System information indicator field, and reserved bits.

[0310] For example, DCI format 1_0 corresponding to C-RNTI may consist of the Identifier for DCI formats field, FDRA field, TDRA field, VRB-to-PRB mapping field, MCS field, New data indicator (NDI) field, RV field, HARQ process number (HPN) field, Downlink assignment index (DAI) field, TPC command for scheduled PUCCH field, PUCCH resource indicator (PRI) field, and PDSCH-to-HARQ_feedback timing indicator field.

[0311] The configuration of the above DCI fields may be independent of the RRC settings. Therefore, even if the terminal receives RRC settings, the configuration of the above fields may remain fixed.

[0312] Referring to Tables 17 and 18, the lengths of the DCI fields included in the DCI format 1_0 corresponding to each RNTI may be fixed. Here, the FDRA field may be an exception.

[0313] For example, the TDAR field can always be fixed at 4 bits. The MCS field can be fixed at 5 bits. The RV field can be fixed at 2 bits. The HPN field can be fixed at 4 bits. The DAI fields can be fixed at 2 bits. The TPC command for scheduled PUCCH can be fixed at 2 bits. The PRI field can be fixed at 3 bits. The PDSCH-to-HARQ_feedback timing indicator field can be fixed at 3 bits. In addition, the Identifier for DCI formats field, VRB-to-PRB mapping field, NDI field, and System information indicator field can be fixed at 1 bit.

[0314] Therefore, the terminal can always receive DCI fields of the same length.

[0315] In a specific network deployment environment, a base station may not require certain DCI fields or may require DCI fields of shorter length. However, the base station cannot change the configuration and lengths of the DCI fields of the fallback DCI, or furthermore, the length of the fallback DCI, to suit the network deployment environment.

[0316] For example, if the available frequency band width of the base station is small, interleaved mapping through the VRB-to-PRB mapping field may not be necessary. Therefore, the VRB-to-PRB mapping field can be excluded from the DCI format.

[0317] For example, if the base station uses only some time domain scheduling(s), a 4-bit TDRA field may not be needed, or only a TDRA field of smaller bit length may be needed.

[0318] For example, if a base station uses only some modulation(s) or some coding scheme(s), a 5-bit MCS field may not be needed, or only a smaller bit-length MCS field may be needed.

[0319] For example, if the base station uses only some redundancy version(s) (e.g., 0), a 2-bit RV field may not be needed, or only a smaller bit-length RV field may be needed.

[0320] For example, if the base station uses only some HARQ process number(s), a 4-bit HPN field may not be needed, or only a smaller bit-length HPN field may be needed.

[0321] For example, a base station may not require a 2-bit DAI field, or may only require a 1-bit DAI field.

[0322] For example, if the base station uses only some power control value(s), the 3 bits TPC command for scheduled PUCCH field may not be needed, or only a TPC command for scheduled PUCCH field of smaller bits length may be needed.

[0323] For example, if a base station uses only some PUCCH resource value(s), a 3-bit PRI field may not be needed, or only a PRI field of shorter bit length may be needed.

[0324] For example, if the base station uses only some PDSCH-to-HARQ_feedback timing values, the 3-bit PDSCH-to-HARQ_feedback timing indicator field may not be needed, or only a PDSCH-to-HARQ_feedback timing indicator field of less bit length may be needed.

[0325] As another example, if the configuration of the DCI fields included in the fallback DCI is fixed, the base station cannot introduce new DCI fields into the fallback DCI. For instance, as the communication system evolves, the base station may introduce new functions. For instance, a new function could be a technology that enhances the performance of the terminal during random access. In this case, the fallback DCI must include a DCI field corresponding to the new function. However, if the configuration of the DCI fields included in the fallback DCI is fixed, the base station cannot include a DCI field corresponding to the new function in the fallback DCI, even if it supports the new function.

[0326] To solve the aforementioned problem, some bits or code point values ​​among the DCI fields included in the fallback DCI can be repurposed for new functions without introducing a new DCI field in the fallback DCI. However, this method may restrict the functions of the existing DCI fields.

[0327] In this disclosure, methods for solving the above-mentioned problem are disclosed.

[0328] According to the method of the present disclosure, a base station can set the configuration of DCI fields included in the fallback DCI, the length of each DCI field, and the total length of the fallback DCI to suit the deployment environment of the base station.

[0329] The more specific method is as follows.

[0330] The base station can set the configuration and length of the DCI fields included in the fallback DCI for the terminal. For example, the base station may set the inclusion status and length for each DCI field for the terminal. The inclusion status may be set by the length of the DCI field.

[0331] For example, if '0' bits are set for a specific DCI field, said DCI field may be excluded from the fallback DCI. In this case, the terminal may perform a terminal operation corresponding to the DCI field based on a default value set by the base station. Here, the terminal operation corresponding to the default value may be the same as the terminal operation corresponding when the value of the specific DCI field is '0'.

[0332] For example, if the VRB-to-PRB mapping field is '0' bits, the terminal can perform a terminal operation corresponding to when the value of the VRB-to-PRB mapping field is '0'. Here, the terminal operation corresponding to when the value of the VRB-to-PRB mapping field is '0' may be non-interleaved.

[0333] For example, if 'X' bits are set for a specific DCI field, the terminal can receive terminal operations corresponding to each code point of the 'X' bits from the base station. For example, the terminal receives 0, 1, ..., 2 from the 'X' bits. X One of the values ​​-1 can be obtained, and a terminal operation configured for each of the above values ​​can be performed. According to one method, the terminal, for a specific DCI field, for each code point (0, 1, 2) of the 'Y' bits Y The terminal operation corresponding to -1) can be set from the base station. If X <Y이면 단말은 설정 받은 코드포인트 (0,1,...,2 Y -1) among (0,1,...,2 X -1) Only can be used. Alternatively, Y bits can be created by adding the '0' of YX bits to the MSB (most significant bits) of X bits, and the corresponding terminal operation can be performed by interpreting the said Y bits.

[0334] For example, for the TDRA field, time domain resource allocation information corresponding to each code point (0, 1, ..., 15) of Y=4 bits can be set. If the terminal is set X=2 bits for the TDRA field, the terminal can perform terminal operations based on time domain resource allocation information corresponding to code points (0, 1, 2, 3) of X=2 bits.

[0335] For example, if the length is not set for a specific DCI field, the terminal may consider that the maximum length of the DCI field is set. For example, if the length is not set for a TDRA field, the terminal may consider the maximum length that the TDRA field can have (i.e., 4 bits) as the length of the TDRA field.

[0336] For example, if the length is not set for a specific DCI field, the terminal may consider that the DCI field is not included. That is, the DCI field may be considered to be a '0' bit.

[0337] The base station may set the total length of the fallback DCI for the terminal. Here, the total length of the fallback DCI may be equal to or greater than the sum of the lengths of each DCI field. Here, if the total length of the fallback DCI is not set, the total length of the fallback DCI may be equal to the sum of the lengths of each DCI field (including the length of the reserved bits if reserved bits are set).

[0338] Table 19 is a signaling method for setting the configuration and length of a DCI field included in a fallback DCI according to an embodiment of the present disclosure, and the total length of the fallback DCI. Here, MinDCISize and MaxDCISize may be the minimum length (MinDCISize) and maximum length (MaxDCI size) that the fallback DCI can have. Here, reserved bits, the maximum length is N reserved It could be.

[0339] [Table 19]

[0340]

[0341] Referring to Table 19, when the terminal monitors the fallback DCI, the terminal can blind decode the fallback DCI based on the length specified in Total_DCI_size. If the blind decoding of the fallback DCI based on the length specified in Total_DCI_size is successful, the terminal can obtain the DCI fields as follows. The length of the TDRA field can be obtained from TDRA_Field. The length of the VRB-to-PRB_mapping field can be obtained from VRB-to-PRB_mapping_Field. The length of the MCS field can be obtained from MCS_Field. The length of the NDI field can be obtained from NDI_Field. The length of the RV field can be obtained from RV_Field. The length of the HPN field can be obtained from HPN_Field. The length of the DAI field can be obtained from DAI_Field. The length of the TPC_command_for_scheduled_PUCCH field can be obtained from TPC_command_for_scheduled_PUCCH_Field. The length of the PRI field can be obtained from PRI_Field. The length of the PDSCH-to-HARQ_feedback_timing_indicator field can be obtained from PDSCH-to-HARQ_feedback_timing_indicator_Field. The lengths of the other reserved bits can be obtained from Reserved_bits.

[0342] In one embodiment of the present disclosure, when a new function is added to a base station, the base station may add a DCI field corresponding to the new function. To this end, the base station may set the configuration and length of the DCI field corresponding to the new function for the terminal.

[0343] For example, referring to Table 20, the length of the DCI field corresponding to the new function can be set in New_Field. Here, the maximum value of New_Field is N new It could be.

[0344] [Table 20]

[0345]

[0346] Existing terminals (older release terminals that do not support new features) can obtain the lengths of each DCI field, the lengths of reserved bits, and the total length of the DCI format based on Table X3. Here, an existing terminal is a terminal capable of interpreting the DCI fields corresponding to all values ​​in Table X3. However, an existing terminal cannot interpret New_Field, which is the configuration information for the DCI field corresponding to the new feature in Table X4.

[0347] When a setting (New_Field) for a DCI field corresponding to a new function is added, a new terminal (a release terminal that includes the new function and supports the new function) can interpret the setting for the said DCI field, but an existing terminal cannot interpret the added setting. Therefore, when a setting for a DCI field corresponding to a new function is added, interpretation problems may occur for existing terminals.

[0348] To resolve this, the DCI field corresponding to the new function may be located within the reserved bits. And the signaling structure may be as shown in Table 21.

[0349] For existing terminals, the configuration and length of each DCI field, as well as the length of reserved bits and the length of the fallback DCI, can be obtained by referring to Fallback_DCI_For_DL in Table 21. Here, all configuration information in Fallback_DCI_For_DL may be values ​​that the existing terminal can interpret. However, the existing terminal cannot interpret Fallback_DCI_For_DL_New.

[0350] For new terminals, the configuration and length of each DCI field, as well as the length of reserved bits and the length of the fallback DCI, can be obtained by referring to Fallback_DCI_For_DL in Table 21. Additionally, configuration information for the DCI field corresponding to the new function can be obtained by referring to Fallback_DCI_For_DL_New in Table 21. Here, the configuration information for the DCI field corresponding to the new function can be interpreted in one of the following ways. Here, for existing terminals, the reserved bits can be discarded without being interpreted.

[0351] In the first method, the DCI field corresponding to the new function can always be located starting from the first bit of the reserved bits. And the length of the DCI field can be set (e.g., the New_Field_Length parameter in Table 21). That is, the new terminal can consider the bits from the first bit of the reserved bits up to the length of the DCI field (e.g., the New_Field_Length parameter in Table 21) as the DCI field corresponding to the new function. The new terminal can interpret the DCI field.

[0352] According to the second method, the DCI field corresponding to the new function may be located within reserved bits, and within the reserved bits, the starting position and the length of the DCI field may be set (e.g., the New_Field_Start and New_Field_Length parameters of Table 21). That is, the new terminal may consider the bit corresponding to the starting position (e.g., New_Field_Start of Table 21) in the reserved bits up to the bits corresponding to the length of the DCI field (e.g., the New_Field_Length parameter of Table 21) as the DCI field corresponding to the new function. Here, if the starting position (e.g., New_Field_Start of Table 21) is '0', it represents the first bit of the reserved bits. According to the second method, the base station may freely instruct the terminal to the bits used for the DCI field corresponding to the new function among the reserved bits.

[0353] The second method can be used when multiple new functions are introduced. For example, a first terminal may support a first new function but not a second new function. A second terminal may support a second new function but not a first new function. In the case of the first terminal, if it supports the first new function, it can obtain DCI field setting information corresponding to the first new function, but it cannot obtain DCI field setting information for the second new function. Therefore, if the starting position within the reserved bits is always fixed as in the first method, the first terminal always obtains the DCI field for the first new function from the starting position of the reserved bits. However, in the case of the second terminal, it always obtains the DCI field for the second new function from the starting position of the reserved bits. Consequently, a problem may arise where the two terminals interpret the same bits as different functions. According to the second method, if the starting position within the reserved bits is set, the above problem can be resolved.

[0354] [Table 21]

[0355]

[0356] In the example described above, the DCI field configuration can be set per RNTI or common to all RNTIs.

[0357] When a base station configures DCI fields included in a fallback DCI for a terminal, the inclusion of each DCI field may be set for each DCI format corresponding to an RNTI. For example, a DCI field with the same name (e.g., an MCS field) may be included in multiple DCI formats corresponding to multiple RNTIs. According to one method, a first length may be set for a DCI field (e.g., an MCS field) included in a DCI format corresponding to a first RNTI (e.g., SI-RNTI), and a second length may be set for a DCI field (e.g., an MCS field) included in a DCI format corresponding to a second RNTI (e.g., C-RNTI).

[0358] When a base station configures DCI fields included in a fallback DCI for a terminal, the inclusion of each DCI field may be set for each DCI format corresponding to an RNTI. For example, a DCI field with the same name (e.g., an MCS field) may be included in multiple DCI formats corresponding to multiple RNTIs. According to one method, a first length may be set for a DCI field (e.g., an MCS field) included in a DCI format corresponding to a first RNTI (e.g., SI-RNTI), and a second length may be set for a DCI field (e.g., an MCS field) included in a DCI format corresponding to a second RNTI (e.g., C-RNTI).

[0359] [Configuration Container]

[0360] The base station must transmit the configuration information of Tables 19 to 21 to the terminal. Here, the container to which the configuration information is transmitted may be at least one of the following.

[0361] The first container may be a PSS (primary synchronization signal), an SSS (secondary synchronization signal), or a DMRS (demodulation reference signal) of a PBCH. More specifically, a specific sequence may be transmitted to the PSS, SSS, and DMRS of the PBCH. The terminal receives the PSS, SSS, and DMRS of the PBCH and can determine a value corresponding to the sequence. Based on the value corresponding to the sequence, the terminal can obtain the length of the fallback DCI and a combination of the included DCI fields.

[0362] If the value corresponding to the sequence satisfies the first condition, the terminal can receive a fallback DCI based on the length of the first fallback DCI and a combination of the included DCI fields. If the cell ID satisfies the second condition, the terminal can receive a fallback DCI based on the length of the second fallback DCI and a combination of the included DCI fields.

[0363] Here, the first condition may be that the value corresponding to the sequence is even, and the second condition may be that the value corresponding to the sequence is odd.

[0364] Here, the first condition may be that the value corresponding to the sequence is less than or equal to a certain value, and the second condition may be that the value corresponding to the sequence exceeds a certain value.

[0365] Here, the terminal may have a cell ID as the value corresponding to the sequence of PSS and SSS.

[0366] The second container may be a PBCH. Here, the PBCH is a channel that transmits the cell's minimum system information (MIB) and may be a channel that transmits periodically. The PBCH may be the first channel received after obtaining downlink sync information when the terminal connects to the cell. The terminal may obtain the length of the fallback DCI and the combination of included DCI fields from the PBCH. The terminal may interpret the fallback DCI received after receiving the PBCH, through the random connection process and until the completion of the RRC connection, based on the length of the fallback DCI and the combination of included DCI fields obtained from the PBCH.

[0367] For reference, PBCH coverage and downlink overhead may include only limited information.

[0368] For example, the terminal may be instructed by the PBCH to use 1 bit for one of the first length and the second length as the total length of the fallback DCI. Here, the first length and the second length may be values ​​agreed upon in advance by the base station and the terminal (values ​​defined in a standard document).

[0369] For example, the terminal may be instructed by the PBCH as a 1-bit combination of one of the first and second combinations of DCI fields included in the fallback DCI. Here, the first and second combinations may be combinations agreed upon in advance by the base station and the terminal (combinations defined in the standard document).

[0370] The third container may be SIB1. In the case of a DCI format (DCI corresponding to SI-RNTI) that schedules SIB1, the terminal can receive and interpret the DCI format based on a combination of a fixed length and fixed DCI fields. Then, it can obtain the length of the fallback DCI and the combination of DCI fields from SIB1 as shown in Tables 19 and 21. The terminal can interpret the fallback DCI received from SIB1 until the random connection process and the completion of the RRC connection based on the length of the fallback DCI and the combination of DCI fields included obtained from the SIB1. Alternatively, it can receive a search space (e.g., type-1 CSS) from SIB1. Limited to the search space, the DCI can be monitored using the length of the fallback DCI and the combination of DCI fields.

[0371] The fourth container may be SIBx. The terminal refers to SIBx as one of the SIBs other than SIB1. In the case of the DCI format (DCI corresponding to SI-RNTI) that schedules SIB1, the terminal can receive and interpret the DCI format based on a combination of a fixed length and a fixed DCI field. The terminal can obtain whether SIBx is transmitted from SIB1. If the transmission of SIBx is indicated by SIB1, the terminal can monitor the DCI format (DCI corresponding to SI-RNTI) that schedules SIBx. In this case, the terminal can receive and interpret the DCI format based on a combination of a fixed length and a fixed DCI field. (i.e., the DCI format (corresponding to SI-RNTI) that schedules SIB1 and SIBx has the same length and the same combination of DCI fields.) And from SIBx, the terminal can obtain the length and combination of DCI fields of the fallback DCI as shown in Tables 19 and 20. The terminal can interpret the fallback DCI received from the SIBx until the random connection process and the completion of the RRC connection based on the length of the fallback DCI obtained from the SIBx and the combination of the included DCI fields. Alternatively, it can receive a search space (e.g., type-1 CSS) from the SIBx. Limited to the search space, the DCI can be monitored based on the length of the fallback DCI and the combination of the DCI fields.

[0372] The fifth container may be a RAR (msg 2). In the case of a DCI format (DCI corresponding to SI-RNTI) that schedules SIB1, the terminal may receive and interpret the DCI format based on a combination of a fixed length and fixed DCI fields. The terminal may receive a PDSCH containing a RAR after transmitting a PRACH. In the case of a DCI format (DCI corresponding to RA-RNTI) that schedules the RAR, the terminal may receive and interpret the DCI format based on a combination of a fixed length and fixed DCI fields. Additionally, the terminal may obtain the length of the fallback DCI and the combination of DCI fields from the RAR as shown in Tables 19 and 21. The terminal may interpret the fallback DCI received after receiving the RAR, through the random connection process and until the completion of the RRC connection, based on the length of the fallback DCI obtained from the RAR and the combination of the included DCI fields. Alternatively, the terminal may receive a search space from the RAR. Limited to the above search space, DCI can be monitored by the length of the fallback DCI and a combination of DCI fields.

[0373] When a base station transmits configuration information regarding the length of the DCI format and the combination of DCI fields in a RAR, the base station may determine said configuration information based on a PRACH preamble (msg 1). For example, some of the preambles in the PRACH preamble may correspond to the capabilities of a specific terminal. If the base station sends a RAR corresponding to said PRACH preamble, the base station may transmit configuration information such that the DCI fields corresponding to said terminal capabilities are included in the fallback DCI.

[0374] The 6th container may be msg4 PDSCH. In the case of a DCI format (DCI corresponding to SI-RNTI) that schedules SIB1, the terminal may receive and interpret the DCI format based on a combination of a fixed length and a fixed DCI field. The terminal may receive PDSCH containing RAR after transmitting PRACH. In the case of a DCI format (DCI corresponding to RA-RNTI) that schedules the RAR, the terminal may receive and interpret the DCI format based on a combination of a fixed length and a fixed DCI field. The terminal may transmit msg3 PUSCH based on the UL grant included in the RAR. The terminal may receive PDSCH containing msg4 after transmitting msg3 PUSCH. In the case of a DCI format (DCI corresponding to TC-RNTI) that schedules the msg4 PDSCH, the terminal may receive and interpret the DCI format based on a combination of a fixed length and a fixed DCI field. In addition, the length of the fallback DCI and combinations of DCI fields can be obtained from the msg4 PDSCH as shown in Tables 19 and 21. The terminal can interpret the fallback DCI received from the msg4 PDSCH until the random connection process and the completion of the RRC connection based on the length of the fallback DCI and combinations of DCI fields included obtained from the RAR. Alternatively, a search space can be set from the msg4 PDSCH. Limited to the search space, the DCI can be monitored using the length of the fallback DCI and combinations of DCI fields.

[0375] When a base station transmits configuration information regarding the length of the DCI format and combinations of DCI fields in msg4 PDSCH, the base station may determine said configuration information based on PRACH preamble (msg 1) to Msg3 PUSCH. For example, some of the preambles in the PRACH preamble may correspond to the capabilities of a specific terminal. Additionally, some terminal capabilities may be included in Msg3 PUSCH. The base station may transmit configuration information such that the DCI fields corresponding to said terminal capabilities are included in the fallback DCI.

[0376] In the above-described embodiment, the fixed length and fixed DCI field combination refer to the length and combination agreed upon by the terminal and the base station (length and combination defined in a standard document). Here, the fixed length and fixed DCI field combination refer to the length and combination that the base station cannot change. This may differ from the DCI format length and DCI field combination determined by the terminal based on configuration information regarding the DCI format length and DCI field combination.

[0377] [DCI Size Prioritization]

[0378] According to one embodiment of the present disclosure, a fallback DCI may have multiple lengths. More specifically, until the terminal receives information regarding the length of the fallback DCI and the combination of DCI fields, the terminal may receive a DCI with a predetermined length and a predetermined combination of DCI fields. Here, the predetermined length of the fallback DCI may be referred to as the first DCI length. Then, when the terminal receives configuration information regarding the length of the DCI format and the combination of DCI fields, the terminal may receive a DCI with a combination of the DCI format length and DCI fields determined based on the configuration information. Here, the configured length of the fallback DCI may be referred to as the second DCI length.

[0379] For example, when SIB1 is used among the configuration containers described above, the DCI format for scheduling SIB1 (the DCI format corresponding to SI-RNTI) may be a first DCI length, and subsequent fallback DCIs may be a second DCI length. Accordingly, the terminal can monitor DCIs with multiple lengths for a single DCI format. In this case, since the terminal must blind decode the DCI based on multiple lengths, a problem may arise in which the reception complexity of the terminal increases. Methods for solving this are disclosed.

[0380] In the first method, when a terminal monitors DCI with a first DCI length and a second DCI length in the same PDCCH monitoring opportunity, only one length of DCI can be monitored.

[0381] Here, the PDCCH monitoring opportunity can be determined on a symbol-by-symbol basis. That is, it can be determined based on the OFDM symbol at which the PDCCH reception begins. In other words, if the reception of a PDCCH begins at the same OFDM symbol, it can be considered the same PDCCH monitoring opportunity.

[0382] Here, the PDCCH monitoring opportunity can be determined on a slot basis. That is, it can be determined based on the slot where the PDCCH reception begins. In other words, if the reception of a PDCCH begins in the same slot, it can be considered the same PDCCH monitoring opportunity. If a PDCCH is monitored in slots with different subcarrier intervals, the PDCCH monitoring opportunity can be determined based on the slot with the lowest subcarrier interval.

[0383] In the first method, the first DCI length may always be prioritized. That is, when the terminal monitors the DCI with the first DCI length and the second DCI length in a single PDCCH monitoring opportunity, it may perform blind decoding based on the first DCI length. And it may not perform blind decoding with the second DCI length. The DCI format corresponding to the first DCI length may include a DCI format that schedules SIB1 (a DCI format corresponding to SI-RNTI).

[0384] In the first method, the second DCI length may always be prioritized. That is, when the terminal monitors the DCI with the first DCI length and the second DCI length in a single PDCCH monitoring opportunity, it may perform blind decoding based on the second DCI length. And it may not perform blind decoding with the first DCI length. The DCI format corresponding to the first DCI length may include a DCI format that schedules SIB1 (a DCI format corresponding to SI-RNTI).

[0385] In the first method, blind decoding can be performed based on the longer of the first DCI length and the second DCI length. That is, the terminal can perform blind decoding based on the longer of the first DCI length and the second DCI length during a single PDCCH monitoring opportunity. And blind decoding may not be performed with the shorter DCI length. Here, the base station may transmit the second DCI length by attaching '0' to the DCI format of the shorter DCI length. For example, let the DCI format corresponding to the shorter DCI length be the DCI format for scheduling SIB1 (DCI format corresponding to SI-RNTI). The terminal can perform blind decoding based on the longer DCI length. If the DCI format obtained by blind decoding with the longer DCI length is the DCI format for scheduling SIB1 (DCI format corresponding to SI-RNTI), the terminal can interpret only the bits of the shorter DCI length among the bits included in the said DCI format.

[0386] In the second method, when the terminal monitors DCI with a first DCI length and a second DCI length in the same PDCCH monitoring opportunity, it can monitor both lengths of DCI.

[0387] In this method, when the terminal counts the number of blind decodings, it may separately count the number of blind decodings corresponding to the first DCI length and the number of blind decodings corresponding to the second DCI length. If the counted number of blind decodings is greater than the number of blind decodings supported by the terminal, the terminal may not perform blind decoding for the DCI corresponding to one length. For example, blind decoding corresponding to the second DCI length may not be performed. For example, blind decoding corresponding to the first DCI length may not be performed. For example, blind decoding corresponding to a shorter length may not be performed.

[0388] [Flowchart]

[0389] FIG. 13 is a flowchart of the present disclosure.

[0390] Step 1 (1310): The terminal can monitor the DCI with a first DCI length and a first DCI field combination. Here, the first DCI length and the first DCI field combination refer to a length and combination agreed upon by the terminal and the base station (length and combination defined in a standard document). For example, the first DCI length and the first DCI field combination can be applied to a DCI format that schedules SIB1 (a DCI format corresponding to SI-RNTI). Thus, the terminal can receive the first DCI (a DCI composed of the first DCI length and the first DCI field) without separate signaling.

[0391] Step 2 (1320): The terminal can obtain second DCI length and second DCI field combination setting information from the base station. Here, the second DCI length and second DCI field combination setting information can be received on a downlink channel scheduled by the first DCI. For example, the information may be included in SIB1 scheduled by the first DCI.

[0392] Here, the second DCI length and the second DCI field combination may differ from the first DCI length and the first DCI field combination. In the second DCI field combination, some DCI fields may be included in reserved bits, and the start and length of the DCI fields may be set within the reserved bits.

[0393] Step 3 (1330): After receiving the above-mentioned configuration information, the terminal can monitor the second DCI based on the second DCI length and the second DCI field combination. For example, if the above-mentioned configuration information is received at SIB1, the terminal can monitor the second DCI after SIB1.

[0394] If a DCI of the first DCI length and a DCI of the second DCI length are monitored in the same PDCCH monitoring opportunity, only one DCI length can be monitored.

[0395] <DCI format for multiple purpose>

[0396] A terminal in the RRC_CONNECTED state can monitor a DCI format (DCI format 1_0, 1_1, etc.) for scheduling PDSCH reception or a DCI format (DCI format 0_0, 0_1, etc.) for scheduling PUSCH transmission. The DCI format may be used for purposes other than PDSCH reception scheduling and PUSCH transmission scheduling. In this case, the terminal may use the DCI format for other purposes based on a combination of values ​​of DCI fields defined in the DCI format.

[0397] Figure 14 illustrates the various purposes of the DCI format 1_1 introduced in NR. This is also shown in Table 22.

[0398] DCI format 1_1 can be used to schedule Dynamic grant (DG) PDSCH reception, to activate and deactivate Semi-persistent (SPS) PDSCH, to retransmit SPS PDSCH, to indicate Scell ​​dormancy, to trigger One shot codebook (CB), to retransmit HARQ-ACK CB, or to update the Transmission configuration index (TCI) without PDSCH reception scheduling.

[0399] More specifically, for DCI format 1_1 to schedule DG PDSCH reception, the CRC of DCI format 1_1 must be scrambled to C-RNTI or MCS-C-RNTI, and the FDRA field must have a valid value.

[0400] For DCI format 1_1 to indicate Scell ​​dormancy, the CRC of DCI format 1_1 must be scrambled to C-RNTI or MCS-C-RNTI, the FDRA field must have an invalid value, and if the one-shot HARQ-ACK request field exists, it must indicate '0'. If DCI format 1_1 indicates Scell ​​dormancy, the dormant status of the Scells may be indicated from the MCS field, NDI field, RV field, HPN field, Antenna port field, and DMRS sequence initialization field corresponding to Transport block (TB) 1. Here, the MCS field, NDI field, RV field, HPN field, Antenna port field, and DMRS sequence initialization field corresponding to Transport block (TB) 1 may not be used for their original purpose.

[0401] For DCI format 1_1 to indicate one-shot CB triggering, the CRC of DCI format 1_1 must be scrambled to C-RNTI or MCS-C-RNTI, the FDRA field must have an invalid value, and the one-shot HARQ-ACK request field must indicate '1'. If DCI format 1_1 indicates one-shot CB triggering, the MCS field may indicate the index of the cell included in the CB or the HARQ process numbers. Here, the MCS field may not be used for its original purpose.

[0402] For DCI format 1_1 to indicate HARQ-ACK CB retransmission, the CRC of DCI format 1_1 must be scrambled to C-RNTI or MCS-C-RNTI, the FDRA field must have an invalid value, and the HARQ-ACK retransmission indicator field must indicate '1'. If DCI format 1_1 indicates HARQ-ACK CB retransmission, the MCS field may indicate the index of the slot corresponding to the HARQ-ACK CB to be retransmitted. Here, the MCS field may not be used for its original purpose.

[0403] For DCI format 1_1 to indicate SPS activation, the CRC of DCI format 1_1 must be scrambled with CS-RNTI, the FDRA field must have a valid value, the NDI field must be 0, the HPN field must be '0', and the RV field must be '0'.

[0404] For DCI format 1_1 to indicate SPS retransmission, the CRC of DCI format 1_1 must be scrambled with CS-RNTI, the FDRA field must have a valid value, and the NDI field must be 1.

[0405] For a terminal that receives only one SPS setting, in order for DCI format 1_1 to indicate SPS deactivation, the CRC of DCI format 1_1 must be scrambled with CS-RNTI, the FDRA field must have an invalid value, the NDI field must be 0, the RV field must be '0', the MCS field must be '1', and the HPN field must be '0'.

[0406] For a terminal to receive multiple SPS settings, in order for DCI format 1_1 to indicate SPS deactivation, the CRC of DCI format 1_1 must be scrambled with CS-RNTI, the FDRA field must have an invalid value, the NDI field must be 0, the RV field must be '0', and the MCS field must be '1'. Additionally, the SPS setting to be deactivated may be indicated in the HPN field.

[0407] In order for DCI format 1_1 to instruct a TCI update without PDSCH scheduling, the CRC of DCI format 1_1 must be scrambled with CS-RNTI, the FDRA field must have an invalid value, the NDI field must be 0, the RV field must be '1', and the MCS must be '1'.

[0408] Referring to Table 22, DCI format 1_1 can be used for various purposes other than PDSCH receive scheduling, but the method of indicating each purpose may differ. For example, DCI format 1_1 for updating TCI without PDSCH receive scheduling must be scrambled with CS-RNTI, and the FDRA, NDI, RV, and MCS fields must have specific combination values. In this case, the HPN field is not used. However, DCI format 1_1 for indicating SPS activation must be scrambled with CS-RNTI, and the NDI, HPN (when only one SPS is configured), and RV fields must have specific values. In this case, the MCS field is not used.

[0409] Therefore, when the terminal determines the purpose of DCI format 1_1, it makes the determination based on combinations of different fields. Since the terminal can determine the purpose of DCI format 1_1 using multiple fields and multiple combinations, the complexity of the terminal may increase. In addition, whenever a new purpose is introduced, a new combination of fields may be required. Therefore, it is a method with low scalability.

[0410] [Table 22]

[0411]

[0412] In the present disclosure, a method for solving this is disclosed.

[0413] Unless otherwise noted in the following description, the FDRA field indicates an invalid value. When the FDRA field indicates a valid value, DCI can be used to enable DG PDSCH or SPS PDSCH or to retransmit SPS PDSCH. And SPS PDSCH enabling and SPS PDSCH retransmitting can be distinguished based on the NDI value.

[0414] In the following description, 'invalid value of the FDRA field' may be replaced with a separate indicator or a separate code point. For example, the DCI may include a separate 1-bit indicator, and if the indicator is '0', the DCI is used for scheduling purposes, and if it is '1', it may be reinterpreted and used for other purposes. For example, the DCI may include a TDRA (time domain resource assignment) field, and if the value of the TDRA field indicates a code point other than a specific code point, the DCI is used for scheduling purposes, and if it indicates a specific code point, it may be reinterpreted and used for other purposes.

[0415] In the first method, the terminal can combine some DCI fields of the DCI format to create a first set of DCI fields and combine other DCI fields to create a second set of DCI fields.

[0416] The terminal can determine the use of the DCI format based on the value of the first set of DCI fields.

[0417] The terminal can receive from the base station a DCI format usage corresponding to the value of the first DCI field set. In other words, the terminal can receive from the base station a value of the first DCI field set corresponding to the usage of the DCI format.

[0418] For example, referring to Table 23, Scell ​​dormancy may be set for the DCI format corresponding to the value '0' of the first DCI field set. One shot CB triggering may be set for the DCI format corresponding to the value '1' of the first DCI field set. HARQ-ACK CB retransmission may be set for the DCI format corresponding to the value '2' of the first DCI field set.

[0419] As an example, some values ​​of the first DCI field set may be used for specific purposes only without the base station setting. For example, the value '0' of the first DCI field set may be fixed to Scell ​​dormancy for the DCI format.

[0420] Referring to Table 23, when different RNTIs are used (different RNTIs such as C-RNTI and CS-RNTI), the terminal may use different DCI formats even if the values ​​of the first DCI field set are the same. For example, in Table 23, Scell ​​dormancy may be set to the value '0' of the first DCI field set of the DCI format scrambled with C-RNTI, but SPS deactivation may be set to the value '0' of the first DCI field set of the DCI format scrambled with CS-RNTI. Therefore, the terminal may be configured to use a DCI format corresponding to the value of the first DCI field set for each RNTI.

[0421] The operation of the terminal is as follows.

[0422] The terminal can receive a DCI format. The DCI format may be scrambled into C-RNTI or CS-RNTI. If the DCI format has an invalid FDRA value, the use of the DCI format can be obtained based on the value of the first set of DCI fields of the DCI format. Here, in the case of a DCI format corresponding to C-RNTI, the terminal can receive the use corresponding to C-RNTI from the base station. Here, in the case of a DCI format corresponding to CS-RNTI, the terminal can receive the use corresponding to CS-RNTI from the base station. That is, the value of the first set of DCI fields can be interpreted differently in the DCI format corresponding to C-RNTI and the DCI format corresponding to CS-RNTI.

[0423] Referring to Table 24, even when different RNTIs are used (different RNTIs such as C-RNTI and CS-RNTI), the use of different DCI formats corresponding to the values ​​of the first DCI field set may be the same. For example, in Table 24, if Scell ​​dormancy is set to the value '0' of the first DCI field set, Scell ​​dormancy may be indicated if the value of the first DCI field set of the DCI format is '0', regardless of the RNTI value (whether it is C-RNTI or CS-RNTI).

[0424] The operation of the terminal is as follows.

[0425] The terminal can receive a DCI format. The DCI format can be scrambled into C-RNTI or CS-RNTI. If the DCI format has an invalid FDRA value, the purpose of the DCI format can be obtained based on the value of the first set of DCI fields of the DCI format. The terminal can receive a setting from the base station for a purpose that is common to both C-RNTI and CS-RNTI. That is, the value of the first set of DCI fields can be interpreted commonly in the DCI format corresponding to C-RNTI and the DCI format corresponding to CS-RNTI.

[0426] Additionally, the terminal may expect that a specific use is not indicated in the DCI format corresponding to a specific RNTI. If a specific use corresponding to a specific RNTI is indicated, the terminal may determine that the DCI is an invalid DCI and discard it. Discarding the DCI may indicate that the terminal does not perform the operation indicated in the DCI.

[0427] For example, the DCI format corresponding to C-RNTI may not specify the use of SPS disablement.

[0428] For example, in the DCI format corresponding to CS-RNTI, Scell ​​dormancy or HARQ-ACK CB retransmission or one-shot HARQ-ACK CB triggering may not be indicated.

[0429] The terminal can obtain values ​​required for the indicated use from the values ​​of the second DCI field set.

[0430] The terminal can sequentially concatenate DCI fields included in the second DCI field set to generate a single bit stream. The single bit stream can be interpreted according to the intended use indicated by the value of the first DCI field set. For example, referring to Table 23, if the value of the first DCI field set is '0' and the intended use of the corresponding DCI format is Scell ​​dormancy, the bit stream of the second DCI field set can be used to indicate the dormancy state of the Scells. For example, referring to Table 23, if the value of the first DCI field set is '1' and the intended use of the corresponding DCI format is One shot CB triggering, the bit stream of the second DCI field set can be used to indicate the cell index and HPN index included in the CB. For example, referring to Table 23, if the value of the first DCI field set is '2' and the use of the corresponding DCI format is HARQ-ACK CB retransmission, the bits stream of the second DCI field set can be used to indicate the slot of the HARQ-ACK CB to be retransmitted.

[0431] [Table 23]

[0432]

[0433] [Table 24]

[0434]

[0435] Multiple uses may be set for a single first DCI field value. When determining a use from the first DCI field value, the terminal may be instructed to perform multiple uses rather than a single use. Referring to Table 25, if the first DCI field value is '5', Scell ​​Dormancy and One shot CB triggering may be performed simultaneously. In this case, the second DCI fields may be interpreted as information for Scell ​​Dormancy and One shot CB triggering. More specifically, when the terminal receives multiple uses set in the DCI format from the base station, it may receive a number of bits (N1) to be interpreted as information for the first instruction and a number of bits (N2) to be interpreted as information for the second instruction. The terminal may obtain N1 bits from the MSB to be interpreted as information for the first instruction in the bit stream composed of the second DCI fields. And, N2 bits can be obtained starting from the bits to be interpreted as information for the first instruction. Here, N1+N2 may be less than or equal to the length of the bit stream composed of the second DCI fields.

[0436] [Table 25]

[0437]

[0438] In one embodiment of the present disclosure, the DCI field included in the first DCI field may be an MCS field. Here, the MCS field may be 5 bits. Thus, based on the MCS, the use of up to 32 DCI formats may be indicated. If the DCI schedules multiple transport blocks, the MCS field may correspond to the first transport block.

[0439] In one embodiment of the present disclosure, the DCI field included in the second DCI field may be at least one of the RV field, HPN field, Antenna ports field, and DMRS sequence initialization field.

[0440] In the second method, when the FDRA field indicates an invalid value, a first field and a second field may be defined instead of all fields following the FDRA fields of the DCI format. Here, the first field can perform the same role as the first set of DCI fields described above, and the second field can perform the same role as the second set of DCI fields described above. That is, the first field can indicate the use of the DCI format, and the second field can indicate a value corresponding to the use of the DCI format indicated by the first field.

[0441] The difference from the first method is that the first method did not modify the DCI fields defined in the DCI format. That is, the first set of DCI fields can be composed of predefined DCI fields, and the second set of DCI fields can be composed of the remaining predefined DCI fields. Therefore, the base station must set the configuration of the first set of DCI fields and the second set of DCI fields for the terminal. However, in the second method, instead of the DCI fields defined in the DCI format, they are interpreted as the first field and the second field anew. Therefore, in the second method, only the length of the first field and the length of the second field can be set.

[0442] A new RNTI can be introduced as a third method. In the method described above, when the FDRA field is an invalid value, the DCI format is used for purposes other than PDSCH scheduling. When the DCI format is used for purposes other than PDSCH scheduling, the FDRA field is not required. Therefore, the determination of whether to perform PDSCH scheduling is not made based on the FDRA field, but can be made based on the new RNTI. For example, in the case of a DCI format in which the CRC is scrambled with the new RNTI, the FDRA field may not be included. The above DCI format may include a first field and a second field.

[0443] In the fourth method, a new field may be introduced to indicate whether it is used for PDSCH scheduling or for other purposes. For example, a 1-bit indicator may be included in the DCI format. If the 1-bit is '0', it can be determined that the DCI format is used for PDSCH scheduling. Additionally, the DCI format may include fields such as FDRA, TDRA, MCS, and HPN for scheduling PDSCH. If the 1-bit is '1', it can be determined that the DCI format is used for purposes other than PDSCH scheduling. Additionally, the DCI format may include a first field and a second field.

[0444] In the second to fourth methods, the length of the DCI format may be the same as the DCI format for scheduling PDSCH (DCI format scrambled with C-RNTI). Even if the first and second fields are included, if it is shorter than the DCI format for scheduling PDSCH, it can be padded with '0' to match the length.

[0445] In the first to fourth methods described above, the DCI format may be DCI format 1_0, DCI format 1_1, or any other DCI format. That is, the technology of the present disclosure may not be limited to DCI format 1_1.

[0446] The method described above may be DCI formats that schedule PDSCH, such as DCI format 1_0 and DCI format 1_1. The method described above may be applied to DCI formats that schedule PUSCH, such as DCI format 0_0 and DCI format 0_1.

[0447] [Flowchart]

[0448] FIG. 15 is a drawing illustrating the flowchart of the present disclosure.

[0449] In the first step (1510), the terminal can receive the purpose of the DCI format and the corresponding value (index) from the base station. For example, '0' can be set to Scell ​​Dormancy, '1' to One shot CB triggering, '2' to HARQ-ACK CB retransmission, etc.

[0450] In the second step (1520), the terminal can receive a DCI format from the base station. The terminal can verify the validity of the FDRA field from the DCI format. If the FDRA field is invalid, the terminal can determine the use of the DCI format from the value of the first DCI field(s). Here, the first DCI field may be an MCS field. If the value of the MCS field is '0', the terminal can determine that the DCI format is used for Scell ​​Dormancy. If the value of the MCS field is '1', the terminal can determine that the DCI format is used for One shot CB triggering. If the value of the MCS field is '2', the terminal can determine that the DCI format is used for HARQ-ACK CB retransmission.

[0451] In the third step (1530), the terminal can obtain information about the intended use from the bit stream of the second DCI fields. Here, the second DCI fields may consist of an RV field, an HPN field, an Antenna port field, and DMRS sequence initialization fields. For example, if Scell ​​Dormancy is indicated for the DCI format, it can be determined which Scells are dormant based on the bit stream of the second DCI fields.

[0452] FIG. 16 is a drawing illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0453] Referring to FIG. 16, the terminal may include a transceiver (referring to a terminal receiver unit (1600) and a terminal transmitter unit (1610)), a memory (not shown), and a terminal processing unit (1605, or a terminal control unit or processor). According to the communication method of the terminal described above, the transceiver unit (1600, 1610), memory, and terminal processing unit (1605) of the terminal may operate. The terminal processing unit (1605, or processor) may control the operation of the terminal according to each of the embodiments described above, as well as a combination of at least one embodiment. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more components or fewer components than the components described above. Furthermore, the terminal processing unit (1605), the terminal transmitter unit (1610), the terminal receiver unit (1600), and the memory may be implemented in the form of a single chip.

[0454] The transceiver can transmit and receive signals with a base station. Here, the signal may include control information and data. To this end, the transceiver 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 a received signal and down-converts its frequency. However, this is merely one embodiment of the transceiver, and the components of the transceiver are not limited to an RF transmitter and an RF receiver.

[0455] In addition, the transceiver receives a signal through a wireless channel and outputs it to a processor, and can transmit the signal output from the processor through a wireless channel.

[0456] Memory can store programs and data necessary for the operation of the terminal. Additionally, memory can store control information or data included in signals transmitted and received by the terminal. Memory can be composed of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. Additionally, there may be multiple memories, and memory can store instructions for performing the aforementioned communication method.

[0457] Additionally, the terminal processing unit (1805) can control a series of processes to enable the terminal to operate according to the above-described embodiment. For example, the processor can control the components of the terminal to receive a DCI composed of two layers and receive a plurality of PDSCHs simultaneously. There may be multiple processors, and the processors can perform the control operation of the terminal components by executing a program stored in memory.

[0458] FIG. 17 is a drawing illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0459] Referring to FIG. 17, the base station may include a transceiver unit, which refers to a base station receiver (1700) and a base station transmitter (1710), a memory (not shown), and a base station processing unit (1705, or a base station control unit or processor). According to the communication method of the base station described above, the transceiver unit (1700, 1710), the memory, and the base station processing unit (1705) of the base station may operate. The base station processing unit (1705, or processor) may control the operation of the base station according to each of the embodiments described above, as well as a combination of at least one embodiment. However, the components of the base station are not limited to the examples described above. For example, the base station may include more components or fewer components than the components described above. Furthermore, the base station receiver (1700), base station transmitter (1710), base station processing unit (1705), and memory may be implemented in the form of a single chip.

[0460] The transceiver can transmit and receive signals with a terminal. Here, the signal may include control information and data. To this end, the transceiver 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 a received signal and down-converts its frequency. However, this is merely one embodiment of the transceiver, and the components of the transceiver are not limited to an RF transmitter and an RF receiver.

[0461] In addition, the transceiver receives a signal through a wireless channel and outputs it to a processor, and can transmit the signal output from the processor through a wireless channel.

[0462] The memory can store programs and data necessary for the operation of the base station. Additionally, the memory can store control information or data included in signals transmitted and received by the base station. The memory may be composed of storage media or combinations of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD. Additionally, there may be multiple memories, and the memory can store instructions for performing the aforementioned communication method.

[0463] The base station processing unit (1705) can control a series of processes to enable the base station to operate according to the embodiments of the present disclosure described above. For example, the processor can control each component of the base station to configure two layers of DCIs containing allocation information for a plurality of PDSCHs and to transmit them. There may be multiple processors, and the processors can perform control operations on the components of the base station by executing a program stored in memory.

[0464] Methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0465] When implemented as software, a computer-readable storage medium may be provided for storing one or more programs (software modules). One or more programs stored on the computer-readable storage medium are configured for execution by one or more processors within an electronic device. One or more programs may include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of this disclosure.

[0466] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, ROM (Read Only Memory), Electrically Erasable Programmable Read Only Memory (EEPROM), magnetic disc storage devices, Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs), or other forms of optical storage devices, magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these. Additionally, each constituent memory may include multiple units.

[0467] Additionally, the program may be stored on an attachable storage device accessible via a communication network such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination thereof. Such a storage device may be connected to the device performing the embodiment of the present disclosure through an external port. Additionally, a separate storage device on the communication network may be connected to the device performing the embodiment of the present disclosure.

[0468] In the specific embodiments of the present disclosure described above, the components included in the invention are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural form, it may be composed of a singular form, or even if a component is expressed in the singular form, it may be composed of a plural form.

[0469] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples provided to facilitate the explanation of the technical content of the present disclosure and to aid in understanding the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is obvious to those skilled in the art that other variations based on the technical concept of the present disclosure are possible. Furthermore, each of the above embodiments may be combined and operated as needed. For example, parts of one embodiment of the present disclosure and parts of another embodiment may be combined to operate a base station and a terminal. For example, parts of the first embodiment and the second embodiment of the present disclosure may be combined to operate a base station and a terminal. In addition, although the above embodiments are presented based on an FDD LTE system, other variations based on the technical concept of the above embodiments may be implemented in other systems such as a TDD LTE system, 5G, or NR system.

[0470] Meanwhile, the order of description in the drawings illustrating the method of the present invention does not necessarily correspond to the order of execution, and the order of execution may be changed or executed in parallel.

[0471] Alternatively, drawings describing the method of the present invention may omit some components and include only some components to the extent that the essence of the present invention is not impaired.

[0472] In addition, the method of the present invention may be implemented by combining some or all of the contents included in each embodiment within a scope that does not impair the essence of the invention.

Claims

In a method of operation of a terminal in a wireless communication system, A step of receiving from a base station a DCI format including information indicating whether the DCI (downlink control information) is for scheduling, a first DCI field, and a second DCI field; A step of confirming that the DCI format is not for scheduling purposes based on information indicating whether the DCI is for scheduling purposes; A step of determining the use of the DCI format based on the first DCI field; and A method comprising the step of obtaining information regarding the use of the DCI format determined based on the first DCI field from the bit stream of the second DCI field. In paragraph 1, the information indicating whether the DCI is for scheduling is, A method in which any one of the values ​​of the FDRA (frequency domain resource assignment) field, the TDRA (time domain resource assignment) field, a code point, or a 1-bit indicator. In paragraph 1, If the above first DCI field is the first value, the use of the above DCI format is set to Scell ​​(Secondary Cell) dormancy, and If the first DCI field is the second value, the use of the DCI format is set to One-shot CB (Codebook) triggering, and A method in which, if the first DCI field is a third value, the use of the DCI format is set to HARQ-ACK (hybrid automatic repeat request acknowledgment) CB retransmission. In paragraph 3, if at least two of the first value, the second value, or the third value are set in the first DCI field, the DCI format is used for multiple purposes. In paragraph 4, A method further comprising the step of receiving from the base station a first number of bits (N1) interpreted as information for the first use and a second number of bits (N2) interpreted as information for the second use, when multiple uses are set in the above DCI format. In paragraph 1, A method in which the use of the DCI format according to the first DCI field is determined differently from the DCI format corresponding to the C-RNTI (cell radio network temporary identifier) ​​and the DCI format corresponding to the CS-RNTI (configured scheduling radio network temporary identifier). In paragraph 1, A method in which the bit stream of the second DCI field is generated by sequentially connecting fields included in the second DCI field, and one bit stream represents information regarding the use of the DCI format according to the first DCI field. In a method of operating a base station in a wireless communication system, A step of generating a DCI format including information indicating whether the DCI (downlink control information) is for scheduling, a first DCI field, and a second DCI field; and The method includes the step of transmitting the above DCI format to a terminal, If it is confirmed that the DCI format is not for scheduling purposes based on information indicating whether the above DCI is for scheduling, the use of the above DCI format is determined based on the first DCI field, and A method for obtaining information regarding the use of the DCI format determined based on the first DCI field from the bit stream of the second DCI field. In paragraph 8, the information indicating whether the above DCI is for scheduling is, A method in which any one of the values ​​of the FDRA (frequency domain resource assignment) field, the TDRA (time domain resource assignment) field, a code point, or a 1-bit indicator. In paragraph 8, If the above first DCI field is the first value, the use of the above DCI format is set to Scell ​​(Secondary Cell) dormancy, and If the first DCI field is the second value, the use of the DCI format is set to One-shot CB (Codebook) triggering, and A method in which, if the first DCI field is a third value, the use of the DCI format is set to HARQ-ACK (hybrid automatic repeat request acknowledgment) CB retransmission. In claim 10, if at least two of the first value, the second value, or the third value are set in the first DCI field, the DCI format is used for multiple purposes. In Paragraph 11, A method further comprising the step of transmitting to the terminal a first number of bits (N1) interpreted as information for the first use and a second number of bits (N2) interpreted as information for the second use, when multiple uses are set in the above DCI format. In paragraph 8, A method in which the use of the DCI format according to the first DCI field is determined differently from the DCI format corresponding to the C-RNTI (cell radio network temporary identifier) ​​and the DCI format corresponding to the CS-RNTI (configured scheduling radio network temporary identifier). In a terminal of a wireless communication system, At least one transceiver; At least one processor connected to communicate with the above at least one transceiver; and It includes at least one memory that is communicably connected to the at least one processor and stores instructions that are executable individually or in combination by the at least one processor. The above command is the above terminal: A DCI format is received from a base station, comprising information indicating whether the DCI (downlink control information) is for scheduling, a first DCI field, and a second DCI field. Based on information indicating whether the above DCI is for scheduling, confirm that the above DCI format is not for scheduling purposes, and The use of the DCI format is determined based on the first DCI field above, and A terminal that obtains information regarding the use of the DCI format determined based on the first DCI field from the bit stream of the second DCI field. In a base station of a wireless communication system, At least one transceiver; At least one processor connected to communicate with the above at least one transceiver; and It includes at least one memory that is communicably connected to the at least one processor and stores instructions that are executable individually or in combination by the at least one processor. The above command is the above base station: A DCI format is generated that includes information indicating whether the DCI (downlink control information) is for scheduling, a first DCI field, and a second DCI field, and The above DCI format is transmitted to the terminal, and If it is confirmed that the DCI format is not for scheduling purposes based on information indicating whether the above DCI is for scheduling, the use of the above DCI format is determined based on the first DCI field, and Information regarding the use of the DCI format determined based on the first DCI field is obtained from the bit stream of the second DCI field.

Images