Method and apparatus for downlink control information length alignment in communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. The present disclosure relates to the operation of a user equipment and a base station in a wireless communication system. The present disclosure provides a method for configuring and receiving a downlink control channel in a wireless communication system. The method performed by a user equipment in a communication system, according to an embodiment of the present disclosure, comprises the steps of: receiving configuration information regarding a search space through higher layer signaling, the search space including a user equipment specific search space (USS) and a common search space (CSS); performing downlink control information (DCI) size alignment, the DCI size alignment including configuring the size of a reserved bits field of DCI to be monitored in the USS to be the same as the size of a reserved bits field of the DCI to be monitored in the CSS; and performing physical downlink control channel (PDCCH) monitoring on the basis of the configuration information and the DCI size alignment.

Description

Method and device for aligning downlink control information length in a communication system

[0001] The present disclosure relates to the operation of a terminal and a base station in a communication system. Specifically, the present disclosure relates to a method and device for a terminal to determine the length or size between multiple downlink control information (formats).

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

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

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

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

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

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

[0008] As described above and with the development of wireless communication systems, various services have become available, and methods for providing these services smoothly are required.

[0009] Various embodiments of the present disclosure are intended to provide a device and method capable of effectively providing a service in a wireless communication system.

[0010] The technical problems to be achieved in various embodiments of the present disclosure are not limited to those mentioned above, and other technical problems not mentioned can be considered by a person having ordinary skill in the art from various embodiments of the present disclosure described below.

[0011] The present disclosure proposes a DCI length alignment method. The present disclosure proposes a method for designing a DCI for scheduling multiple cells.

[0012] A method performed by a terminal in a communication system according to one embodiment of the present disclosure includes the steps of: receiving configuration information for a search space through upper layer signaling, wherein the search space includes a user equipment specific search space (USS) and a common search space (CSS); performing downlink control information (DCI) size alignment, wherein the DCI size alignment includes setting a size of a reserved bits field of DCI to be monitored in the USS to be equal to a size of a reserved bits field of DCI to be monitored in the CSS; and performing physical downlink control channel (PDCCH) monitoring based on the configuration information and the DCI size alignment.

[0013] According to one embodiment of the present disclosure, when setting information for a channel access mode is received through the upper layer signaling: the size of a field indicating a channel access type of DCI to be monitored in the CSS is 2 bits, the size of a reserved bit field of the DCI to be monitored in the CSS is 0 bits, and the size of a reserved bit field of the DCI to be monitored in the USS is set to 0 bits according to the DCI size alignment.

[0014] According to one embodiment of the present disclosure, when the setting information for the channel connection mode is not received through the upper layer signaling: the size of the field indicating the channel connection type of the DCI to be monitored in the CSS is 0 bits, the size of the reserved bit field of the DCI to be monitored in the CSS is 2 bits, and the size of the reserved bit field of the DCI to be monitored in the USS is set to 2 bits according to the DCI size alignment.

[0015] According to one embodiment of the present disclosure, the field indicating the setting information for the channel access mode and the channel access type of the DCI to be monitored in the CSS is for FR (frequency range) 2-2.

[0016] According to one embodiment of the present disclosure, the DCI to be monitored in the CSS and the DCI to be monitored in the USS correspond to DCI format 1_0.

[0017] A terminal of a communication system according to one embodiment of the present disclosure includes a transceiver; and a processor connected to the transceiver, wherein the processor is configured to: receive configuration information for a search space through upper layer signaling; the search space includes a user equipment specific search space (USS) and a common search space (CSS); perform downlink control information (DCI) size alignment; the DCI size alignment includes setting a size of a reserved bits field of DCI to be monitored in the USS to be equal to a size of a reserved bits field of DCI to be monitored in the CSS; and perform physical downlink control channel (PDCCH) monitoring based on the configuration information and the DCI size alignment.

[0018] According to one embodiment of the present disclosure, when setting information for a channel access mode is received through the upper layer signaling: the size of a field indicating a channel access type of DCI to be monitored in the CSS is 2 bits, the size of a reserved bit field of the DCI to be monitored in the CSS is 0 bits, and the size of a reserved bit field of the DCI to be monitored in the USS is set to 0 bits according to the DCI size alignment.

[0019] According to one embodiment of the present disclosure, when the setting information for the channel connection mode is not received through the upper layer signaling: the size of the field indicating the channel connection type of the DCI to be monitored in the CSS is 0 bits, the size of the reserved bit field of the DCI to be monitored in the CSS is 2 bits, and the size of the reserved bit field of the DCI to be monitored in the USS is set to 2 bits according to the DCI size alignment.

[0020] According to one embodiment of the present disclosure, the field indicating the setting information for the channel access mode and the channel access type of the DCI to be monitored in the CSS is for FR (frequency range) 2-2.

[0021] According to one embodiment of the present disclosure, the DCI to be monitored in the CSS and the DCI to be monitored in the USS correspond to DCI format 1_0.

[0022] A method performed by a base station in a communication system according to one embodiment of the present disclosure comprises the steps of transmitting configuration information for a search space through upper layer signaling, wherein the search space includes a user equipment specific search space (USS) and a common search space (CSS); and transmitting a physical downlink control channel (PDCCH) related to the configuration information, wherein the PDCCH is related to downlink control information (DCI) size alignment, and the DCI size alignment is related to setting a size of a reserved bits field of DCI to be transmitted in the USS to be equal to a size of a reserved bits field of DCI to be transmitted in the CSS.

[0023] According to one embodiment of the present disclosure, when setting information for a channel access mode is transmitted through the upper layer signaling: the size of a field indicating a channel access type of DCI to be transmitted in the CSS is 2 bits, the size of a reserved bit field of the DCI to be transmitted in the CSS is 0 bits, and the size of a reserved bit field of the DCI to be transmitted in the USS is 0 bits.

[0024] According to one embodiment of the present disclosure, when the setting information for the channel connection mode is not transmitted through the upper layer signaling: the size of the field indicating the channel connection type of the DCI to be transmitted in the CSS is 0 bits, the size of the reserved bit field of the DCI to be transmitted in the CSS is 2 bits, and the size of the reserved bit field of the DCI to be transmitted in the USS is 2 bits.

[0025] According to one embodiment of the present disclosure, a base station of a communication system comprises: a transceiver; and a processor connected to the transceiver, wherein the processor is configured to: transmit configuration information for a search space through upper layer signaling; wherein the search space includes a user equipment specific search space (USS) and a common search space (CSS); and transmit a physical downlink control channel (PDCCH) related to the configuration information, wherein the PDCCH is related to downlink control information (DCI) size alignment, and the DCI size alignment is related to setting a size of a reserved bits field of DCI to be transmitted in the USS to be equal to a size of a reserved bits field of DCI to be transmitted in the CSS.

[0026] According to one embodiment of the present disclosure, when setting information for a channel access mode is transmitted through the upper layer signaling: the size of a field indicating a channel access type of DCI to be transmitted in the CSS is 2 bits, the size of a reserved bit field of the DCI to be transmitted in the CSS is 0 bits, and the size of a reserved bit field of the DCI to be transmitted in the USS is 0 bits.

[0027] According to one embodiment of the present disclosure, when the setting information for the channel connection mode is not transmitted through the upper layer signaling: the size of the field indicating the channel connection type of the DCI to be transmitted in the CSS is 0 bits, the size of the reserved bit field of the DCI to be transmitted in the CSS is 2 bits, and the size of the reserved bit field of the DCI to be transmitted in the USS is 2 bits.

[0028] Various embodiments of the present disclosure provide devices and methods capable of effectively providing services in a wireless communication system.

[0029] The effects that can be obtained from various embodiments of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by a person having ordinary skill in the art based on the detailed description below.

[0030] FIG. 1 is a diagram illustrating a basic structure of a time-frequency domain in a wireless communication system according to one embodiment of the present disclosure.

[0031] FIG. 2 is a diagram illustrating a frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

[0032] FIG. 3 is a diagram illustrating an example of bandwidth portion settings in a wireless communication system according to one embodiment of the present disclosure.

[0033] FIG. 4 is a diagram illustrating an example of setting a control region of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.

[0034] 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.

[0035] FIG. 6 is a diagram for explaining a method for a base station and a terminal to transmit and receive data in consideration of a downlink data channel and rate matching resources in a wireless communication system according to one embodiment of the present disclosure.

[0036] 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.

[0037] 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.

[0038] FIG. 9 is a diagram illustrating an example of time axis resource allocation according to subcarrier spacing of a data channel and a control channel in a wireless communication system according to one embodiment of the present disclosure.

[0039] FIG. 10 is a diagram illustrating a wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation, and dual connectivity situation in a wireless communication system according to one embodiment of the present disclosure.

[0040] FIG. 11 is a diagram illustrating an example of a DCI length alignment method to which one embodiment of the present disclosure is applicable.

[0041] FIG. 12 is a diagram illustrating a problem of a DCI length alignment method applicable to one embodiment of the present disclosure. FIG. 13 is a diagram illustrating that MC-DCI includes multiple FDRA fields.

[0042] FIG. 14 is a diagram illustrating cell determination that is scheduled based on multiple FDRA fields included in MC-DCI.

[0043] FIG. 15 is a diagram showing an example of the operation of a terminal and a base station according to one embodiment of the present disclosure.

[0044] FIG. 16 is a diagram illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0045] FIG. 17 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

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

[0047] In describing the embodiments, descriptions of technical details that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to avoid obscuring the gist of the present disclosure by omitting unnecessary explanations and to convey the gist more clearly.

[0048] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0049] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification. In addition, when describing the present disclosure, if a specific description of a related function or configuration is determined to unnecessarily obscure the gist of the present disclosure, the detailed description thereof will be omitted. In addition, the terms described below are terms defined in consideration of the functions of the present disclosure, and these may vary depending on the intention or custom of the user or operator. Therefore, their definitions should be made based on the contents throughout the specification.

[0050] Hereinafter, the base station is an entity that performs resource allocation of the terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station to a terminal, and uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station. In addition, although the LTE or LTE-A system may be described below as an example, the embodiments of the present disclosure may also be applied to other communication systems having a similar technical background or channel type. For example, the 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included here, and the 5G below may also 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 through some modifications within a scope that does not significantly deviate from the scope of the present disclosure, as judged by a person having skilled technical knowledge.

[0051] At this time, it will be understood that each block of the processing flowchart drawings and combinations of the flowchart drawings can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flowchart block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flowchart block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0052] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0053] Here, the term '~ part' used in this embodiment means software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and the '~ part' performs certain roles. However, the '~ part' is not limited to software or hardware. The '~ part' may be configured to be on an addressable storage medium or may be configured to play one or more processors. Therefore, as an example, the '~ part' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ parts' may be combined into a smaller number of components and '~ parts' or further separated into additional components and '~ parts'. Additionally, the components and '~parts' may be implemented to activate one or more CPUs within a device or secure multimedia card. In addition, in an embodiment, the '~parts' may include one or more processors.

[0054] Wireless communication systems are evolving from providing voice-oriented services in the early days to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as communication standards such as 3GPP's HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2's HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE's 802.16e.

[0055] As a representative example of the above broadband wireless communication system, the LTE system adopts the OFDM (Orthogonal Frequency Division Multiplexing) method in the downlink (DL) and the SC-FDMA (Single Carrier Frequency Division Multiple Access) method in the uplink (UL). The uplink refers to a wireless link in 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 in which a base station transmits data or control signals to a terminal. The above multiple access method can distinguish the data or control information of each user by allocating and operating the time-frequency resources for transmitting data or control information to each user so that they do not overlap, that is, so as to achieve orthogonality.

[0056] As a future communications system beyond LTE, 5G communication systems must be able to freely reflect the diverse needs of users and service providers. Therefore, they must support services that simultaneously satisfy these diverse requirements. Services being considered for 5G communication systems include enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliability Low Latency Communication (URLLC).

[0057] eMBB aims to provide data transmission rates that are significantly higher than those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must be able to support a peak data rate of 20 Gbps in the downlink and a peak data rate of 10 Gbps in the uplink from the perspective of a single base station. Furthermore, 5G communication systems must simultaneously provide the peak data rate and an increased user-perceived data rate for terminals. To meet these requirements, improvements in various transmission and reception technologies, including improved multi-input, multi-output (MIMO) transmission technology, are required. Furthermore, while LTE transmits signals using a maximum transmission bandwidth of 20 MHz in the 2 GHz band, 5G communication systems can meet the data transmission rates required by 5G communication systems by using a wider frequency bandwidth than 20 MHz in the 3-6 GHz or higher 6 GHz band.

[0058] At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide the IoT, mMTC requires supporting large-scale terminal connections within a cell, improved terminal coverage, enhanced battery life, and reduced terminal costs. The IoT requires the ability to support a large number of terminals (e.g., 1,000,000 terminals / km2) within a cell, as it provides communication capabilities through the attachment of various sensors and devices. Furthermore, due to the nature of the service, terminals supporting mMTC are likely to be located in shadow areas, such as basements, beyond cell coverage. This may require broader coverage compared to other services provided by 5G communication systems. Terminals supporting mMTC must be inexpensive, and since frequent battery replacement is unlikely, they may require extremely long battery lifespans, such as 10 to 15 years.

[0059] Finally, URLLC refers to a cellular-based wireless communication service used for a specific purpose (mission-critical). For example, services such as remote control of robots or machinery, industrial automation, unmanned aerial vehicles, remote health care, and emergency alerts can be considered. Therefore, the communication provided by URLLC must provide very low latency and very high reliability. For example, a service supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds and, at the same time, must have a 10 -5The following packet error rate (PER) requirements apply. Therefore, for services supporting URLLC, 5G systems must provide a smaller Transmit Time Interval (TTI) than other services. Simultaneously, design considerations may require the allocation of extensive resources in the frequency band to ensure communication link reliability.

[0060] The three 5G services—eMBB, URLLC, and mMTC—can be multiplexed and transmitted within a single system. To meet the differing requirements of each service, different transmission and reception techniques and parameters can be used. Of course, 5G is not limited to the three services described above.

[0061] [NR time-frequency resources]

[0062] Below, the frame structure of the 5G system is described in more detail with reference to drawings.

[0063] Figure 1 is a diagram illustrating the basic structure of the time-frequency domain, which is a radio resource domain in which data or control channels are transmitted in a 5G system.

[0064] The horizontal axis of Figure 1 represents the time domain, and the vertical axis represents the frequency domain. The basic unit of resources in the time and frequency domains is a resource element (RE, 101), which can be defined as 1 OFDM (Orthogonal Frequency Division Multiplexing) symbol (102) on the time axis and 1 subcarrier (103) on the frequency axis. In the frequency domain (For example, 12) consecutive REs can form one resource block (RB, 104).

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

[0066] Figure 2 illustrates an example of a structure of a frame (Frame, 200), a subframe (Subframe, 201), and a slot (Slot, 202). One frame (200) can be defined as 10 ms. One subframe (201) can be defined as 1 ms, and therefore one frame (200) can be composed of a total of 10 subframes (201). One slot (202, 203) can be defined as 14 OFDM symbols (i.e., the number of symbols per slot ( )=14). 1 subframe (201) may be composed of one or more slots (202, 203), and the number of slots (202, 203) per 1 subframe (201) may vary depending on the setting value μ (204, 205) for the subcarrier spacing. In an example of FIG. 2, the cases where μ = 0 (204) and μ = 1 (205) as the subcarrier spacing setting value are illustrated. When μ = 0 (204), 1 subframe (201) may be composed of 1 slot (202), and when μ = 1 (205), 1 subframe (201) may be composed of 2 slots (203). That is, the number of slots per 1 subframe ( ) may vary, and accordingly the number of slots per frame ( ) may vary. Depending on the subcarrier spacing setting μ and can be defined as shown in Table 1 below.

[0067] [Table 1]

[0068]

[0069] [Bandwidth Part (BWP)]

[0070] Next, the bandwidth part (BWP) setting in the 5G communication system will be explained in detail with reference to the drawing.

[0071] FIG. 3 is a diagram illustrating an example of bandwidth portion settings in a wireless communication system according to one embodiment of the present disclosure.

[0072] Figure 3 shows an example in which the UE bandwidth (300) is set to two bandwidth portions, namely, bandwidth portion #1 (BWP#1) (301) and bandwidth portion #2 (BWP#2) (302). The base station can set one or more bandwidth portions to the UE, and can set information such as Table 2 below for each bandwidth portion.

[0073] [Table 2]

[0074]

[0075] Of course, the above example is not limited, and in addition to the above configuration information, various parameters related to the bandwidth portion can be configured for the terminal. The above information can be transmitted from the base station to the terminal via upper layer signaling, for example, RRC (Radio Resource Control) signaling. At least one bandwidth portion among the configured one or more bandwidth portions can be activated. Whether or not the configured bandwidth portion is activated can be semi-statically transmitted from the base station to the terminal via RRC signaling or dynamically transmitted via DCI (Downlink Control Information).

[0076] According to some embodiments, a terminal before RRC (Radio Resource Control) connection can receive configuration information for an initial bandwidth portion (Initial BWP) for initial access from a base station through a Master Information Block (MIB). More specifically, the terminal can receive configuration information for a control region (Control Resource Set, CORESET) and a search space where a PDCCH for receiving system information (which may correspond to Remaining System Information (RMSI) or System Information Block 1 (SIB1)) required for initial access can be transmitted through the MIB during the initial access phase. The control region and search space configured by the MIB may each be regarded as identifier (ID) 0. The base station can notify the terminal of configuration information such as frequency allocation information, time allocation information, and numerology for control region #0 through the MIB. In addition, the base station can notify the terminal of configuration information for a monitoring cycle and occasion for control region #0, i.e., configuration information for search space #0, through the MIB. The terminal may consider the frequency range set as control area #0 obtained from the MIB as the initial bandwidth portion for initial connection. At this time, the identifier (ID) of the initial bandwidth portion may be considered as 0.

[0077] The settings for the bandwidth supported by the above 5G can be used for various purposes.

[0078] In some embodiments, when the bandwidth supported by a terminal is smaller than the system bandwidth, this can be supported through bandwidth portion configuration. For example, the base station can configure the bandwidth portion frequency location (configuration information 2) for the terminal, thereby allowing the terminal to transmit and receive data at a specific frequency location within the system bandwidth.

[0079] Additionally, in some embodiments, a base station may configure multiple bandwidth segments for a terminal to support different numerologies. For example, to support data transmission and reception using both 15 kHz and 30 kHz subcarrier spacing for a given terminal, two bandwidth segments may be configured with subcarrier spacings of 15 kHz and 30 kHz, respectively. The different bandwidth segments may be frequency-division multiplexed, and when data is to be transmitted and received using a specific subcarrier spacing, the bandwidth segment configured for that subcarrier spacing may be activated.

[0080] Furthermore, in some embodiments, the base station may configure bandwidth portions with different bandwidth sizes for the terminal for the purpose of reducing power consumption of the terminal. For example, if the terminal supports a very large bandwidth, for example, 100 MHz, and constantly transmits and receives data using that bandwidth, very large power consumption may occur. In particular, monitoring unnecessary downlink control channels using a large bandwidth of 100 MHz in a situation where there is no traffic may be very inefficient in terms of power consumption. To reduce power consumption of the terminal, the base station may configure a bandwidth portion with a relatively small bandwidth, for example, 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 receive data using the 100 MHz bandwidth portion according to the instructions of the base station.

[0081] In the method for setting the bandwidth part, terminals before RRC connection (Connected) can receive setting information for the initial bandwidth part through the MIB (Master Information Block) in the initial access stage. More specifically, the terminal can set a control region (Control Resource Set, CORESET) for a downlink control channel on which DCI (Downlink Control Information) for scheduling a SIB (System Information Block) can be transmitted from the MIB of the PBCH (Physical Broadcast Channel). The bandwidth of the control region set by the MIB can be regarded as the initial bandwidth part, and the terminal can receive the PDSCH (Physical Downlink Shared Channel) on which the SIB is transmitted through the set initial bandwidth part. In addition to the purpose of receiving the SIB, the initial bandwidth part can also be utilized for other system information (Other System Information, OSI), paging, and random access.

[0082] [Bandwidth Part (BWP) Change]

[0083] When one or more bandwidth part values ​​are set for a terminal, the base station can instruct the terminal to change (or switch, transition) the bandwidth part value using the bandwidth part indicator field in the DCI. For example, in FIG. 3, when the currently activated bandwidth part of the terminal is bandwidth part #1 (301), the base station can instruct the terminal to bandwidth part #2 (302) using the bandwidth part indicator in the DCI, and the terminal can perform a bandwidth part change to bandwidth part #2 (302) indicated by the bandwidth part indicator in the received DCI.

[0084] As described above, since DCI-based bandwidth part change can be indicated by DCI scheduling PDSCH or PUSCH, when a terminal receives a bandwidth part change request, it must be able to receive or transmit PDSCH or PUSCH scheduled by the corresponding DCI without difficulty in the changed bandwidth part. To this end, the standard stipulates the delay time (T) required when changing the bandwidth part. BWP ) and can be defined as in Table 3, for example.

[0085] [Table 3]

[0086]

[0087] The bandwidth-partial change delay time requirement supports Type 1 or Type 2 depending on the terminal's capability. The terminal can report the supported bandwidth-partial delay time type to the base station.

[0088] According to the requirement for bandwidth part change delay time mentioned above, when the terminal receives DCI including bandwidth part change indicator in slot n, the terminal changes to the new bandwidth part indicated by the bandwidth part change indicator in slot n+T. BWP The completion can be done at a later time, and transmission and reception for the data channel scheduled by the DCI can be performed in the new bandwidth portion that has been changed. When the base station wants to schedule a data channel in the new bandwidth portion, the terminal's bandwidth portion change delay time (T BWP ), time domain resource allocation for the data channel can be determined. That is, when the base station schedules the data channel with a new bandwidth portion, the data channel can be scheduled after the bandwidth portion change delay time in the method of determining the time domain resource allocation for the data channel. Accordingly, the terminal can determine whether the DCI instructing the bandwidth portion change is after the bandwidth portion change delay time (T BWP) may not be expected to indicate a slot offset (K0 or K2) value smaller than that.

[0089] If the terminal receives DCI (e.g., DCI format 1_1 or 0_1) indicating a bandwidth change, the terminal may not perform any transmission or reception during the time period from the third symbol of the slot in which the PDCCH including the DCI is received to the start point of the slot indicated by the slot offset (K0 or K2) value indicated by the time domain resource allocation indicator field in the DCI. For example, if the terminal receives DCI indicating a bandwidth change in slot n and the slot offset value indicated by the DCI is K, the terminal may not perform any transmission or reception from the third symbol of slot n to the symbol before slot n+K (i.e., the last symbol of slot n+K-1).

[0090] [SS / PBCH block]

[0091] Next, we will explain the SS (Synchronization Signal) / PBCH block in 5G.

[0092] An SS / PBCH block may refer to a physical layer channel block consisting of a PSS (Primary SS), SSS (Secondary SS), and PBCH. Specifically, it is as follows.

[0093] - PSS: A signal that serves as a reference for downlink time / frequency synchronization and provides some information about the cell ID.

[0094] - SSS: It serves as a reference for downlink time / frequency synchronization and provides the remaining cell ID information not provided by PSS. Additionally, it can serve as a reference signal for PBCH demodulation.

[0095] - PBCH: Provides essential system information required for the terminal's data channel and control channel transmission and reception. Essential system information may include search space-related control information indicating radio resource mapping information for the control channel, and scheduling control information for a separate data channel that transmits system information.

[0096] - SS / PBCH Block: An SS / PBCH block is composed of a combination of PSS, SSS, and PBCH. One or more SS / PBCH blocks can be transmitted within a 5ms period, and each transmitted SS / PBCH block can be distinguished by an index.

[0097] The terminal can detect PSS and SSS in the initial access stage, and decode PBCH. The terminal can obtain MIB from PBCH, and can set control region (Control Resource Set; CORESET) #0 (which may correspond to a control region with a control region index of 0) therefrom. The terminal can monitor control region #0, assuming that the selected SS / PBCH block and the DMRS (Demodulation Reference Signal) transmitted in control region #0 are QCL (Quasi Co Location). The terminal can receive system information through downlink control information transmitted in control region #0. The terminal can obtain RACH (Random Access Channel) related configuration information required for initial access from the received system information. The terminal can transmit PRACH (Physical RACH) to the base station considering the selected SS / PBCH index, and the base station receiving the PRACH can obtain information on the SS / PBCH block index selected by the terminal. The base station can know that the terminal has selected a block among each SS / PBCH block and monitors the control region #0 associated with it.

[0098] [PDCCH: DCI related]

[0099] Next, we will specifically explain downlink control information (DCI) in the 5G system.

[0100] In a 5G system, scheduling information for uplink data (or physical uplink shared channel (PUSCH)) or downlink data (or physical downlink shared channel (PDSCH)) is transmitted from a base station to a terminal via DCI. The terminal can monitor a DCI format for fallback and a DCI format for non-fallback for the PUSCH or PDSCH. The fallback DCI format can be composed of fixed fields defined between the base station and the terminal, and the non-fallback DCI format can include configurable fields.

[0101] DCI can be transmitted through the Physical Downlink Control Channel (PDCCH) after going through the channel coding and modulation process. A Cyclic Redundancy Check (CRC) is attached to the DCI message payload, and the CRC can be scrambled with a Radio Network Temporary Identifier (RNTI) corresponding to the identity of the UE. Different RNTIs can be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control command, or random access response. That is, the RNTI is not transmitted explicitly, but is included in the CRC calculation process. When the UE receives a DCI message transmitted on the PDCCH, it verifies the CRC using the assigned RNTI. If the CRC verification result is correct, the UE can determine that the message was transmitted to the UE.

[0102] For example, a DCI scheduling a PDSCH for System Information (SI) may be scrambled with SI-RNTI. A DCI scheduling a PDSCH for a Random Access Response (RAR) message may be scrambled with RA-RNTI. A DCI scheduling a PDSCH for a Paging message may be scrambled with P-RNTI. A DCI notifying a Slot Format Indicator (SFI) may be scrambled with SFI-RNTI. A DCI notifying a Transmit Power Control (TPC) may be scrambled with TPC-RNTI. A DCI scheduling a UE-specific PDSCH or PUSCH may be scrambled with C-RNTI (Cell RNTI).

[0103] DCI format 0_0 can be used as a fallback DCI for scheduling PUSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 0_0 with the CRC scrambled with C-RNTI can include, for example, the information in Table 4.

[0104] [Table 4]

[0105]

[0106] DCI format 0_1 ​​can be used as a fallback DCI for scheduling PUSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 0_1 ​​with the CRC scrambled with C-RNTI can include, for example, the information in Table 5.

[0107] [Table 5]

[0108]

[0109]

[0110] DCI format 1_0 can be used as a fallback DCI for scheduling PDSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 1_0 with the CRC scrambled with C-RNTI can include, for example, the information in Table 6.

[0111] [Table 6]

[0112]

[0113] DCI format 1_1 can be used as a fallback DCI for scheduling PDSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 1_1 with the CRC scrambled with C-RNTI can include, for example, the information in Table 7.

[0114] [Table 7]

[0115]

[0116]

[0117] [PDCCH: CORESET, REG, CCE, Search Space]

[0118] Below, the downlink control channel in a 5G communication system will be described in more detail with reference to drawings.

[0119] FIG. 4 is a diagram illustrating an example of a control region (Control Resource Set, CORESET) in which a downlink control channel is transmitted in a 5G wireless communication system. FIG. 4 illustrates an example in which two control regions (Control Region #1 (401), Control Region #2 (402)) are set within a UE bandwidth part (410) in the frequency axis and one slot (420) in the time axis. The control regions (401, 402) may be set to specific frequency resources (403) within the entire UE bandwidth part (410) in the frequency axis. The time axis may be set to one or more OFDM symbols, which may be defined as the control region length (Control Resource Set Duration, 404). Referring to the example illustrated in FIG. 4, Control Region #1 (401) is set to a control region length of two symbols, and Control Region #2 (402) is set to a control region length of one symbol.

[0120] In the aforementioned 5G, the control region can be established by the base station to the terminal via higher-layer signaling (e.g., system information, Master Information Block (MIB), Radio Resource Control (RRC) signaling). Establishing a control region for the terminal means providing information such as the control region identifier, the frequency location of the control region, and the symbol length of the control region. For example, this information may include the information in Table 8.

[0121] [Table 8]

[0122]

[0123]

[0124] 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 are in a QCL (Quasi Co Located) relationship with the DMRS transmitted in the corresponding control region.

[0125] FIG. 5 is a diagram showing an example of a basic unit of time and frequency resources that constitute a downlink control channel that can be used in 5G. According to FIG. 5, the basic unit of time and frequency resources that constitute a control channel can be referred to as a REG (Resource Element Group, 503), and a 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 concatenate REGs (503) to constitute a downlink control channel allocation unit.

[0126] 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), 1 CCE (504) can be composed of multiple REGs (503). Taking the REG (503) illustrated in FIG. 5 as an example, the REG (503) can be composed of 12 REs, and if 1 CCE (504) is composed of 6 REGs (503), 1 CCE (504) can be composed of 72 REs. When a downlink control region is set, the region 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 region. CCEs (504) within the control area are distinguished by numbers, and the numbers of the CCEs (504) can be assigned according to a logical mapping method.

[0127] The basic unit of the downlink control channel illustrated in FIG. 5, that is, the REG (503), may include both the REs to which the DCI is mapped and the areas to which the DMRS (505), which is a reference signal for decoding the REs, is mapped. As shown in FIG. 5, three DMRSs (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 a 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 (CCEs) that a terminal must attempt to decode at a given aggregation level. Since there are multiple aggregation levels, each of which can be a set of 1, 2, 4, 8, or 16 CCEs, a terminal can have multiple search spaces. A search space set can be defined as the set of search spaces at all configured aggregation levels.

[0128] Search spaces can be categorized into common search spaces and UE-specific search spaces. A certain group of UEs, or all UEs, can search the common search space of the PDCCH to receive cell-common control information, such as dynamic scheduling of system information or paging messages. For example, PDSCH scheduling allocation information for transmitting SIBs, including cell operator information, can be received by searching the common search space of the PDCCH. In the case of the common search space, since a certain group of UEs, or all UEs, must receive the PDCCH, it can be defined as a set of pre-arranged CCEs. Scheduling allocation information for UE-specific PDSCH or PUSCH can be received by searching the UE-specific search space of the PDCCH. The UE-specific search space can be defined UE-specifically as a function of the UE's identity and various system parameters.

[0129] In 5G, parameters for the search space for 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 can configure the number of PDCCH candidates at each aggregation level L, the monitoring period for the search space, the monitoring occasion for each symbol within the slot for the search space, the search space type (common search space or terminal-specific search space), the combination of DCI format and RNTI to be monitored in the corresponding search space, the control region index to be monitored for the search space, etc. to the terminal. For example, the information in Table 9 can be included.

[0130] [Table 9]

[0131]

[0132]

[0133] Depending on the configuration information, the base station may configure one or more search space sets for the terminal. In some embodiments, the base station may configure search space set 1 and search space set 2 for the terminal, and may configure the terminal to monitor DCI format A scrambled with X-RNTI in search space set 1 in a common search space, and may configure the terminal to monitor DCI format B scrambled with Y-RNTI in search space set 2 in a terminal-specific search space.

[0134] According to the configuration information, one or more search space sets may exist in a common search space or a terminal-specific search space. For example, search space set #1 and search space set #2 may be configured as a common search space, and search space set #3 and search space set #4 may be configured as terminal-specific search spaces.

[0135] In the common search space, the following combinations of DCI formats and RNTIs can be monitored. Of course, the examples below are not limited to these.

[0136] - 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

[0137] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0138] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0139] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0140] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0141] In a terminal-specific search space, the following combinations of DCI formats and RNTIs can be monitored. Of course, the examples below are not limited to these examples.

[0142] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0143] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0144] The RNTIs specified may follow the definitions and uses below.

[0145] C-RNTI (Cell RNTI): For terminal-specific PDSCH scheduling purposes

[0146] TC-RNTI (Temporary Cell RNTI): For terminal-specific PDSCH scheduling purposes

[0147] CS-RNTI (Configured Scheduling RNTI): Used for terminal-specific PDSCH scheduling that is set semi-statically.

[0148] RA-RNTI (Random Access RNTI): Used for PDSCH scheduling in the random access phase.

[0149] P-RNTI (Paging RNTI): Used for scheduling PDSCH where paging is transmitted.

[0150] SI-RNTI (System Information RNTI): Used for scheduling PDSCH where system information is transmitted.

[0151] INT-RNTI (Interruption RNTI): Used to indicate whether pucturing is in progress for PDSCH.

[0152] TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to indicate power control commands for PUSCH.

[0153] TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to indicate power control commands for PUCCH.

[0154] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to indicate power control commands for SRS.

[0155] The aforementioned specified DCI formats may follow definitions such as the examples in Table 10.

[0156] [Table 10]

[0157]

[0158] In 5G, the search space of aggregation level L in the control region p and search space set s can be expressed as in the following mathematical expression 1.

[0159] [Mathematical Formula 1]

[0160]

[0161] - : Integration level

[0162] - : Carrier Index

[0163] - : Total number of CCEs existing within the control region p

[0164] - : slot index

[0165] - : Number of PDCCH candidates for aggregation level L

[0166] - : PDCCH candidate index of aggregation level L

[0167] -

[0168] - , , , , ,

[0169] - : Terminal identifier

[0170] The value can be 0 for a common search space.

[0171] In the case of a terminal-specific search space, the value may correspond to a value that changes depending on the terminal's identity (C-RNTI or ID set to the terminal by the base station) and the time index.

[0172] In 5G, since multiple search space sets can be configured with different parameters (e.g., parameters in Table 9), the set of search space sets monitored by a terminal at each point in time can be different. 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 can monitor both search space set #1 and search space set #2 in a specific slot, or can monitor either search space set #1 or search space set #2 in a specific slot.

[0173] [Rate matching / Puncturing related]

[0174] Below, the rate matching operation and puncturing operation are described in detail.

[0175] When a time and frequency resource A, through which an arbitrary symbol sequence A is to be transmitted, overlaps with an arbitrary time and frequency resource B, a rate matching or puncturing operation may be considered for transmission and reception operations of channel A considering resource C, an area in which resources A and B overlap. The specific operations may follow the contents below.

[0176] Rate Matching Operation

[0177] - The base station can map and transmit channel A only for the remaining resource areas excluding resource C corresponding to the overlapping area with resource B among the entire resources A that want to transmit symbol sequence A to the terminal. For example, if symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol #4}, resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the base station can sequentially map and transmit symbol sequence A to {resource #1, resource #2, resource #4}, which are the remaining resources among resource A excluding {resource #3} corresponding to resource C. As a result, the base station can map and transmit symbol sequences {symbol #1, symbol #2, symbol #3} to {resource #1, resource #2, resource #4}, respectively.

[0178] The terminal can determine resources A and B from scheduling information for symbol sequence A from the base station, and can thereby determine resource C, which is an area where resources A and B overlap. The terminal can receive symbol sequence A, assuming that symbol sequence A was mapped and transmitted in the remaining area of ​​the entire resource A except for resource C. For example, if symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol #4}, and resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the terminal can receive symbol sequence A, assuming that it was sequentially mapped to {resource #1, resource #2, resource #4}, which are the remaining resources among resource A except for {resource #3}, which corresponds to resource C. As a result, the terminal can perform a series of subsequent reception operations, assuming that symbol sequences {symbol #1, symbol #2, symbol #3} were mapped and transmitted to {resource #1, resource #2, resource #4}, respectively.

[0179] Puncture action

[0180] If a base station wants to transmit symbol sequence A to a terminal, and there is a resource C corresponding to an area overlapping with resource B among all resources A, the base station maps symbol sequence A to the entire resource A, but does not perform transmission in the resource area corresponding to resource C, and can perform transmission only for the remaining resource areas of resource A excluding resource C. For example, if symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol #4}, resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the base station can map symbol sequence A {symbol #1, symbol #2, symbol #3, symbol #4} to resource A {resource #1, resource #2, resource #3, resource #4}, and transmit only symbol sequences {symbol #1, symbol #2, symbol #4} corresponding to resources {resource #1, resource #2, resource #4}, which are the remaining resources except {resource #3} corresponding to resource C among resources A, and may not transmit {symbol #3} mapped to {resource #3} corresponding to resource C. As a result, the base station can transmit symbol sequences {symbol #1, symbol #2, symbol #4} by mapping them to {resource #1, resource #2, resource #4}, respectively.

[0181] The terminal can determine resources A and B from scheduling information for symbol sequence A from the base station, and can thereby determine resource C, which is an area where resources A and B overlap. The terminal can receive symbol sequence A assuming that symbol sequence A is mapped to the entire resource A, but is transmitted only in the remaining area of ​​resource area A excluding resource C. For example, if symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol #4}, resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the terminal can assume that symbol sequence A {symbol #1, symbol #2, symbol #3, symbol #4} is mapped to resource A {resource #1, resource #2, resource #3, resource #4} respectively, but {symbol #3} mapped to {resource #3} corresponding to resource C is not transmitted, and can receive it assuming that symbol sequence {symbol #1, symbol #2, symbol #4} corresponding to {resource #1, resource #2, resource #4}, which are the remaining resources among resource A except {resource #3} corresponding to resource C, are mapped and transmitted. As a result, the terminal can assume that the symbol sequence {symbol #1, symbol #2, symbol #4} is transmitted by being mapped to {resource #1, resource #2, resource #4}, respectively, and perform a series of subsequent receiving operations.

[0182] Below, we describe a method for configuring rate-matching resources for the purpose of rate-matching in 5G communication systems. Rate-matching refers to adjusting the size of a signal based on the amount of resources available for transmission. For example, rate-matching a data channel may mean adjusting the size of data accordingly, without mapping the data channel to a specific time and frequency resource region.

[0183] FIG. 6 is a diagram for explaining a method for a base station and a terminal to transmit and receive data in consideration of a downlink data channel and rate matching resources in a wireless communication system according to one embodiment of the present disclosure.

[0184] FIG. 6 illustrates a downlink data channel (PDSCH, 601) and a rate matching resource (602). A base station can configure one or more rate matching resources (602) to a terminal through upper layer signaling (e.g., RRC signaling). Rate matching resource (602) configuration information may include time-domain resource allocation information (603), frequency-domain resource allocation information (604), and period information (605). In the following, the bitmap corresponding to the frequency-domain resource allocation information (604) is named “first bitmap,” the bitmap corresponding to the time-domain resource allocation information (603) is named “second bitmap,” and the bitmap corresponding to the period information (605) is named “third bitmap.” If all or part of the time and frequency resources of the scheduled data channel (601) overlap with the set rate matching resources (602), the base station can rate-match and transmit the data channel (601) 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.

[0185] The base station can dynamically notify the terminal via DCI whether to rate-match the data channel in the set rate-matching resource portion through additional configuration (corresponding to the “rate-matching indicator” in the aforementioned DCI format). Specifically, the base station can select some of the set rate-matching resources and group them into rate-matching resource groups, and can use a bitmap to indicate to the terminal via DCI whether the data channel for each rate-matching resource group is rate-matched. For example, if four rate-matching resources, RMR#1, RMR#2, RMR#3, and RMR#4, are set, the base station can set RMG#1={RMR#1, RMR#2}, RMG#2={RMR#3, RMR#4} as the rate-matching groups, and can use two bits in the DCI field to indicate to the terminal whether to rate-match in RMG#1 and RMG#2, respectively, using a bitmap. For example, if rate matching is required, it can be indicated as “1”, and if rate matching is not required, it can be indicated as “0”.

[0186] 5G supports granularity at the "RB symbol level" and "RE level" by setting the aforementioned rate matching resources on the terminal. More specifically, the following configuration method can be followed.

[0187] RB symbol level

[0188] A terminal can set up to four RateMatchPatterns for each bandwidth section through upper layer signaling, and one RateMatchPattern can include the following contents.

[0189] - As a reserved resource within the bandwidth section, a resource in which the time and frequency resource domains of the reserved resource are set by combining a bitmap at the RB level and a bitmap at the symbol level along the frequency axis may be included. The reserved resource may span one or two slots. A time domain pattern (periodicityAndPattern) in which the time and frequency domains composed of each RB level and symbol level bitmap pair are repeated may additionally be set.

[0190] - It may include a time and frequency domain resource area set as a control resource set within the bandwidth section and a resource area corresponding to a time domain pattern set as a search space setting in which the resource area is repeated.

[0191] RE level

[0192] The terminal can be configured with the following contents through upper layer signaling.

[0193] - The configuration information (lte-CRS-ToMatchAround) for RE corresponding to the LTE CRS (Cell-specific Reference Signal or Common Reference Signal) pattern may include the number of LTE CRS ports (nrofCRS-Ports) and the LTE-CRS-vshift(s) value (v-shift), the location information (carrierFreqDL) of the center subcarrier of the LTE carrier from the reference frequency point (e.g., reference point A), the bandwidth size (carrierBandwidthDL) information of the LTE carrier, and the subframe configuration information (mbsfn-SubframConfigList) corresponding to the MBSFN (Multicast-broadcast single-frequency network). Based on the above-described information, the terminal can determine the location of the CRS within the NR slot corresponding to the LTE subframe.

[0194] - It may include configuration information for a set of resources corresponding to one or more ZP (Zero Power) CSI-RSs within the bandwidth section.

[0195] [PDSCH / PUSCH: Frequency Resource Allocation Related]

[0196] FIG. 7 is a diagram illustrating an example of frequency-axis resource allocation of a physical downlink shared channel (PDSCH) or a physical uplink shared channel (PUSCH) in a wireless communication system according to one embodiment of the present disclosure.

[0197] FIG. 7 is a diagram illustrating three frequency axis resource allocation methods, type-0 (7-00), type-1 (7-05), and dynamic switch (7-10), which can be set through an upper layer in an NR wireless communication system.

[0198] Referring to Fig. 7, if the terminal is configured to use only type-0 resource allocation through upper layer signaling (7-00), some downlink control information (DCI) that allocates PDSCH / PUSCH to the terminal is N RBG Contains a bitmap consisting of N bits. RBG refers to the number of RBGs (resource block groups) determined as shown in [Table 11] below according to the BWP size allocated by the BWP indicator and the upper layer parameter rbg-Size, and data is transmitted to the RBG indicated as 1 by the bitmap.

[0199] [Table 11]

[0200]

[0201] The size of the BWP is the number of RBs included in the BWP. More specifically, when type-0 resource allocation is instructed, the length of the frequency domain resource assignment (FDRA) field of the DCI received by the terminal is the number of RBGs (N RBG ) and Here, the first RBG is It contains RBs of the dog, and the last RBG is On the other hand, contains the RBs of , otherwise, It contains RBs of RBs. The remaining RBGs contain P RBs, where P is the number of nominal RBGs determined according to Table 11.

[0202] If the terminal is configured to use only type-1 resource allocation through upper layer signaling (7-05), the DCI that allocates PDSCH / PUSCH to the terminal is It contains frequency domain resource allocation information (FDRA) consisting of bits. Here, is the number of RBs included in the BWP. Through this, the base station can set the starting VRB (7-20) and the length of frequency axis resources (7-25) allocated continuously therefrom.

[0203] If a terminal is configured to use both type-0 resource allocation and type-1 resource allocation through upper layer signaling (7-10), some DCIs that allocate PDSCH / PUSCH to the terminal include frequency-axis resource allocation information consisting of bits of the larger value (7-35) among the payload (7-15) for configuring type-0 resource allocation and the payload (7-20, 7-25) for configuring type-1 resource allocation. The conditions for this will be explained later. At this time, one bit may be added to the most significant bit (MSB) of the frequency-axis resource allocation information in the DCI, and if the bit has a value of '0', it may indicate that type-0 resource allocation is used, and if the bit has a value of '1', it may indicate that type-1 resource allocation is used.

[0204] [PDSCH / PUSCH: Time Resource Allocation Related]

[0205] Below, a time domain resource allocation method for data channels in next-generation mobile communication systems (5G or NR systems) is described.

[0206] A base station can set up a table for time domain resource allocation information for a downlink data channel (Physical Downlink Shared Channel, PDSCH) and an uplink data channel (Physical Uplink Shared Channel, PUSCH) to a terminal through higher layer signaling (e.g., RRC signaling). A table with up to maxNrofDL-Allocations=16 entries can be set up for PDSCH, and a table with up to maxNrofUL-Allocations=16 entries can be set up for PUSCH. In one embodiment, the time domain resource allocation information may include PDCCH-to-PDSCH slot timing (corresponding to the time interval in slot units between the time point at which a PDCCH is received and the time point at which a PDSCH scheduled by the received PDCCH is transmitted, denoted as K0), PDCCH-to-PUSCH slot timing (corresponding to the time interval in slot units between the time point at which a PDCCH is received and the time point at which a PUSCH scheduled by the received PDCCH is transmitted, denoted as K2), information on the position and length of the start symbol for which a PDSCH or PUSCH is scheduled within a slot, the mapping type of the PDSCH or PUSCH, etc. For example, information such as [Table 12] or [Table 13] below may be transmitted from the base station to the terminal.

[0207] [Table 12]

[0208]

[0209] [Table 13]

[0210]

[0211] 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 in the DCI). The terminal may obtain the time domain resource allocation information for the PDSCH or PUSCH based on the DCI received from the base station.

[0212] 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.

[0213] Referring to FIG. 8, the base station can indicate the time axis position of the PDSCH resource according to the subcarrier spacing (SCS) (μPDSCH, μPDCCH) of the data channel and control channel set using the upper layer, the scheduling offset (K0) value, and the start position (8-00) and length (8-05) of the OFDM symbol within a slot dynamically indicated through DCI.

[0214] FIG. 9 is a diagram illustrating an example of time-domain resource allocation according to subcarrier spacing of a data channel and a control channel in a wireless communication system according to one embodiment of the present disclosure.

[0215] Referring to FIG. 9, when the subcarrier spacing of the data channel and the control channel are the same (9-00, μPDSCH = μPDCCH), the slot numbers for data and control are the same, so the base station and the terminal can generate a scheduling offset according to a predetermined slot offset K0. On the other hand, when the subcarrier spacing of the data channel and the control channel are different (9-05, μPDSCH ≠ μPDCCH), the slot numbers for data and control are different, so the base station and the terminal can generate a scheduling offset according to a predetermined slot offset K0 based on the subcarrier spacing of the PDCCH.

[0216] [PUSCH: Transmission Method Related]

[0217] Next, we describe the scheduling method for PUSCH transmission. PUSCH transmission can be dynamically scheduled by the UL grant within the DCI or can operate by configured grant Type 1 or Type 2. Dynamic scheduling instructions for PUSCH transmission are possible using DCI formats 0_0 or 0_1.

[0218] Configured grant Type 1 PUSCH transmission can be semi-statically configured by receiving configuredGrantConfig including rrc-ConfiguredUplinkGrant of [Table 14] through higher-level signaling, without receiving UL grant in DCI. Configured grant Type 2 PUSCH transmission can be semi-persistently scheduled by UL grant in DCI after receiving configuredGrantConfig not including rrc-ConfiguredUplinkGrant of [Table 14] through higher-level signaling. When PUSCH transmission operates by configured grant, parameters applied to PUSCH transmission are applied through configuredGrantConfig of [Table 14], which is higher-level signaling, except for dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, and scaling of UCI-OnPUSCH provided by pusch-Config of [Table 15]. If the terminal has been provided with transformPrecoder in configuredGrantConfig, which is the upper signaling of [Table 14], the terminal applies tp-pi2BPSK in pusch-Config of [Table 15] to PUSCH transmission operated by the configured grant.

[0219] [Table 14]

[0220]

[0221]

[0222] Next, the PUSCH transmission method is described. The DMRS antenna port for PUSCH transmission is the same as the antenna port for SRS transmission. PUSCH transmission can follow a codebook-based or non-codebook-based transmission method, respectively, depending on whether the value of txConfig in the upper signaling, pusch-Config in [Table 15], is 'codebook' or 'nonCodebook'.

[0223] As described above, PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1, and can be semi-statically configured by configured grant. If the UE is instructed to schedule PUSCH transmission via DCI format 0_0, the UE performs beam configuration for PUSCH transmission using pucch-spatialRelationInfoID corresponding to the UE-specific PUCCH resource corresponding to the minimum ID within the activated uplink BWP within the serving cell, and the PUSCH transmission is based on a single antenna port. The UE does not expect scheduling for PUSCH transmission via DCI format 0_0 within a BWP where a PUCCH resource including pucch-spatialRelationInfo is not configured. If the UE does not configure txConfig in pusch-Config of [Table 15], the UE does not expect to be scheduled with DCI format 0_1.

[0224] [Table 15]

[0225]

[0226]

[0227] Next, we describe codebook-based PUSCH transmission. Codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1, and can operate semi-statically based on a configured grant. When codebook-based PUSCH is dynamically scheduled via DCI format 0_1 ​​or semi-statically configured via a configured grant, the UE determines a precoder for PUSCH transmission based on the SRS Resource Indicator (SRI), Transmission Precoding Matrix Indicator (TPMI), and transmission rank (the number of PUSCH transmission layers).

[0228] At this time, the SRI can be given through the SRS resource indicator field in the DCI or configured through the srs-ResourceIndicator higher-level signaling. The UE is configured with at least one SRS resource when transmitting a codebook-based PUSCH, and can be configured with up to two. When the UE receives an SRI through the DCI, the SRS resource indicated by the SRI refers to the SRS resource corresponding to the SRI among the SRS resources transmitted before the PDCCH containing the SRI. In addition, the TPMI and transmission rank can be given through the precoding information and number of layers fields in the DCI or configured through the precodingAndNumberOfLayers higher-level signaling. The TPMI is used to indicate the precoder applied to the PUSCH transmission. If the UE is configured with one SRS resource, the TPMI is used to indicate the precoder to be applied to the configured one SRS resource. When a terminal is configured with multiple SRS resources, TPMI is used to indicate the precoder to be applied in the SRS resource indicated through SRI.

[0229] The precoder to be used for PUSCH transmission is 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 UE determines the codebook subset based on the TPMI and codebookSubset in the upper layer signaling, pusch-Config. The codebookSubset in the upper layer signaling, pusch-Config, can be set to one of 'fullyAndPartialAndNonCoherent', 'partialAndNonCoherent', or 'nonCoherent' based on the UE capability reported by the UE to the base station. If the UE reported 'partialAndNonCoherent' as the UE capability, the UE does not expect the value of codebookSubset in the upper layer signaling to be set to 'fullyAndPartialAndNonCoherent'. Additionally, if the UE reports 'nonCoherent' as the UE capability, the UE does not expect the value of the upper signaling codebookSubset to be set to 'fullyAndPartialAndNonCoherent' or 'partialAndNonCoherent'. If nrofSRS-Ports in the upper signaling SRS-ResourceSet points to two SRS antenna ports, the UE does not expect the value of the upper signaling codebookSubset to be set to 'partialAndNonCoherent'.

[0230] The terminal can be configured with one SRS resource set in which the usage value in the upper signaling SRS-ResourceSet is set to 'codebook', and one SRS resource in the SRS resource set can be indicated via SRI. If multiple SRS resources are configured in the SRS resource set in which the usage value in the upper signaling SRS-ResourceSet is set to 'codebook', the terminal expects that the value of nrofSRS-Ports in the upper signaling SRS-Resource is set to the same value for all SRS resources.

[0231] The terminal transmits to the base station one or more SRS resources included in the SRS resource set in which the usage value is set to 'codebook' according to upper signaling, and the base station selects one of the SRS resources transmitted by the terminal and instructs the terminal to perform PUSCH transmission using transmission beam information of the corresponding SRS resource. At this time, in codebook-based PUSCH transmission, the SRI is used as information for selecting an index of one SRS resource and is included in the DCI. Additionally, the base station includes in the DCI information indicating the TPMI and rank to be used by the terminal for PUSCH transmission. The terminal performs PUSCH transmission by applying the indicated rank and the precoder indicated by the TPMI based on the transmission beam of the corresponding SRS resource using the SRS resource indicated by the SRI.

[0232] Next, we describe non-codebook-based PUSCH transmission. Non-codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1, and can operate semi-statically based on a configured grant. If at least one SRS resource is configured within an SRS resource set in which the usage value in the upper signaling SRS-ResourceSet is set to 'nonCodebook', the UE can be scheduled for non-codebook-based PUSCH transmission via DCI format 0_1.

[0233] For an SRS resource set in which the usage value in the upper signaling SRS-ResourceSet is set to 'nonCodebook', the UE can be configured with one connected NZP CSI-RS resource (non-zero power CSI-RS). The UE 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 UE is less than 42 symbols, the UE does not expect information about the precoder for SRS transmission to be updated.

[0234] If the value of resourceType in the upper signaling SRS-ResourceSet is set to 'aperiodic', the connected NZP CSI-RS is indicated by the SRS request field in DCI format 0_1 ​​or 1_1. At this time, if the connected NZP CSI-RS resource is an aperiodic NZP CSI-RS resource, the presence of the connected NZP CSI-RS is indicated when the value of the SRS request field in DCI format 0_1 ​​or 1_1 is not '00'. At this time, the DCI must not indicate cross-carrier or cross BWP scheduling. In addition, if the value of the SRS request indicates the presence of an NZP CSI-RS, the NZP CSI-RS is located in the slot in which the PDCCH including the SRS request field is transmitted. At this time, the TCI states set for the scheduled subcarriers are not set to QCL-TypeD.

[0235] If a periodic or semi-persistent SRS resource set is configured, the associated NZP CSI-RS can be indicated through the associatedCSI-RS in the upper-level signaling SRS-ResourceSet. For non-codebook-based transmission, the UE does not expect the upper-level signaling spatialRelationInfo for the SRS resource and the associatedCSI-RS in the upper-level signaling SRS-ResourceSet to be configured together.

[0236] When multiple SRS resources are configured, the UE can determine the precoder and transmission rank to be applied to PUSCH transmission based on the SRI indicated by the base station. At this time, the SRI can be indicated through the SRS resource indicator field in the DCI or can be set through the srs-ResourceIndicator, which is a higher-level signaling. Similar to the codebook-based PUSCH transmission described above, when the UE receives an SRI through the DCI, the SRS resource indicated by the SRI refers to the SRS resource corresponding to the SRI among the SRS resources transmitted before the PDCCH containing the SRI. The UE can use one or more SRS resources for SRS transmission, and the maximum number of SRS resources that can be simultaneously transmitted in the same symbol within one SRS resource set and the maximum number of SRS resources are determined by the UE capability reported by the UE to the base station. At this time, the SRS resources that the UE simultaneously transmits occupy the same RB. The UE configures one SRS port for each SRS resource. Only one SRS resource set with the usage value set to 'nonCodebook' in the upper signaling SRS-ResourceSet can be set, and up to four SRS resources for non-codebook based PUSCH transmission can be set.

[0237] The base station transmits one NZP-CSI-RS associated with an SRS resource set to the terminal, and the terminal calculates a precoder to be used when transmitting one or more SRS resources within the SRS resource set based on the result measured upon reception of the NZP-CSI-RS. When the terminal transmits one or more SRS resources within the SRS resource set with usage set to 'nonCodebook' to the base station, the terminal applies the calculated precoder, and the base station selects one or more SRS resources from the received one or more SRS resources. At this time, in non-codebook based PUSCH transmission, the SRI represents an index that can express a combination of one or more SRS resources, and the SRI is included in the DCI. At this time, the number of SRS resources indicated by the SRI transmitted by the base station can be the number of transmission layers of the PUSCH, and the terminal transmits the PUSCH by applying the precoder applied to SRS resource transmission to each layer.

[0238] [CA / DC related]

[0239] FIG. 10 is a diagram illustrating a wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation, and dual connectivity situation according to one embodiment of the present disclosure.

[0240] Referring to FIG. 10, the wireless protocol of the next-generation mobile communication system is composed of NR SDAP (Service Data Adaptation Protocol S25, S70), NR PDCP (Packet Data Convergence Protocol S30, S65), NR RLC (Radio Link Control S35, S60), and NR MAC (Medium Access Control S40, S55) in the terminal and NR base station, respectively.

[0241] Key features of NR SDAP (S25, S70) may include some of the following:

[0242] - Transfer of user plane data

[0243] - Mapping function between QoS flow and data bearer for both DL and UL

[0244] - Marking function of QoS flow ID for both uplink and downlink (marking QoS flow ID in both DL and UL packets)

[0245] - Ability to map reflective QoS flow to data bearer for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

[0246] For the above SDAP layer device, the terminal can be configured by RRC message for each PDCP layer device, each bearer, or each logical channel, whether to use the header of the SDAP layer device or whether to use the function of the SDAP layer device, and when the SDAP header is configured, the terminal can instruct the NAS QoS reflection configuration 1-bit indicator (NAS reflective QoS) and the AS QoS reflection configuration 1-bit indicator (AS reflective QoS) of the SDAP header to update or reset the mapping information for the QoS flow and data bearer of the uplink and downlink. The SDAP header can include QoS flow ID information indicating QoS. The QoS information can be used as data processing priority, scheduling information, etc. to support a smooth service.

[0247] The main functions of NR PDCP (S30, S65) may include some of the following functions:

[0248] - Header compression and decompression (ROHC only)

[0249] - User data transfer function

[0250] - In-sequence delivery of upper layer PDUs

[0251] - Out-of-sequence delivery of upper layer PDUs

[0252] - PDCP PDU reordering for reception

[0253] - Duplicate detection of lower layer SDUs

[0254] - Retransmission function (Retransmission of PDCP SDUs)

[0255] - Encryption and decryption functions (Ciphering and deciphering)

[0256] - Timer-based SDU discard in uplink.

[0257] The reordering function of the NR PDCP device above refers to a function of reordering PDCP PDUs received from a lower layer in order based on the PDCP SN (sequence number), and may include a function of transmitting data to an upper layer in the reordered order. Alternatively, the reordering function of the NR PDCP device may include a function of transmitting data directly without considering the order, a function of recording lost PDCP PDUs by reordering the order, a function of reporting a status of lost PDCP PDUs to the transmitting side, and a function of requesting retransmission of lost PDCP PDUs.

[0258] The main functions of NR RLC (S35, S60) may include some of the following functions:

[0259] - Data transfer function (Transfer of upper layer PDUs)

[0260] - In-sequence delivery of upper layer PDUs

[0261] - Out-of-sequence delivery of upper layer PDUs

[0262] - ARQ function (Error Correction through ARQ)

[0263] - Concatenation, segmentation and reassembly of RLC SDUs

[0264] - Re-segmentation of RLC data PDUs

[0265] - Reordering of RLC data PDUs

[0266] - Duplicate detection function

[0267] - Protocol error detection

[0268] - RLC SDU discard function

[0269] - RLC re-establishment function

[0270] In the above, the in-sequence delivery function of the NR RLC device refers to the function of sequentially delivering RLC SDUs received from a lower layer to an upper layer. The in-sequence delivery function of the NR RLC device may include a function of reassembling and delivering a single RLC SDU when it is received divided into multiple RLC SDUs, a function of rearranging received RLC PDUs based on the RLC SN (sequence number) or PDCP SN (sequence number), a function of recording lost RLC PDUs by rearranging the order, a function of reporting the status of lost RLC PDUs to the transmitting side, and a function of requesting retransmission of lost RLC PDUs. The in-sequence delivery function of an NR RLC device may include a function to sequentially deliver to the upper layer only the RLC SDUs up to the lost RLC SDU when there is a lost RLC SDU, or may include a function to sequentially deliver to the upper layer all RLC SDUs received before the timer starts if a predetermined timer has expired even if there is a lost RLC SDU. Alternatively, the in-sequence delivery function of an NR RLC device may include a function to sequentially deliver to the upper layer all RLC SDUs received up to the present if a predetermined timer has expired even if there is a lost RLC SDU.In addition, the RLC PDUs may be processed in the order in which they are received (in the order of arrival, regardless of the order of the sequence number) and delivered to the PDCP device out of order (out-of-sequence delivery). In the case of segments, the segments stored in the buffer or to be received later may be received, reconstructed into a complete RLC PDU, processed, and delivered to the PDCP device. The NR RLC layer may not include a concatenation function, and the function may be performed in the NR MAC layer or replaced with a multiplexing function of the NR MAC layer.

[0271] The out-of-sequence delivery function of the NR RLC device above refers to the function of directly delivering RLC SDUs received from a lower layer to an upper layer regardless of the order, and may include a function of reassembling and delivering RLC SDUs when an original RLC SDU is received divided into multiple RLC SDUs, and may include a function of storing the RLC SN or PDCP SN of received RLC PDUs and arranging the order to record lost RLC PDUs.

[0272] NR MAC (S40, S55) can be connected to multiple NR RLC layer devices configured in one terminal, and the main functions of NR MAC can include some of the following functions.

[0273] - Mapping function (Mapping between logical channels and transport channels)

[0274] - Multiplexing / demultiplexing of MAC SDUs

[0275] - Scheduling information reporting function

[0276] - HARQ function (Error correction through HARQ)

[0277] - Priority handling between logical channels of one UE

[0278] - Priority handling between UEs by means of dynamic scheduling

[0279] - MBMS service identification function

[0280] - Transport format selection function

[0281] - Padding function

[0282] The NR PHY layer (S45, S50) can perform operations such as channel coding and modulating upper layer data, converting it into OFDM symbols and transmitting it over a wireless channel, or demodulating and channel decoding OFDM symbols received over a wireless channel and transmitting them to a higher layer.

[0283] The above wireless protocol structure can have various detailed structures depending on the carrier (or cell) operation method. For example, when a base station transmits data to a terminal based on a single carrier (or cell), the base station and the terminal use a protocol structure that has a single structure for each layer, such as S00. On the other hand, when a base station transmits data to a terminal based on carrier aggregation (CA) using multiple carriers in a single TRP (transmission and reception point), the base station and the terminal use a protocol structure that has a single structure up to RLC, such as S10, but multiplexes the PHY layer through the MAC layer. As another example, when a base station transmits data to a terminal based on DC (dual connectivity) using multiple carriers in multiple TRPs, the base station and the terminal use a protocol structure that has a single structure up to RLC, such as S20, but multiplexes the PHY layer through the MAC layer.

[0284] Referring to the above-described PDCCH and beam configuration related descriptions, PDCCH repeated transmission is not supported in current Rel-15 and Rel-16 NR, making it difficult to achieve required reliability in scenarios requiring high reliability such as URLLC. In the present disclosure, a method for repeated PDCCH transmission through multiple transmission points (TRPs) can be provided. The PDCCH reception reliability of a terminal can be improved. Specific methods are described in detail in the following embodiments.

[0285] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the attached drawings. An embodiment of the present disclosure can be applied to, for example, a system such as FDD (Frequency Division Duplex), TDD (Time Division Duplex), and XDD (Cross Division Duplex), but is not limited thereto. In the present disclosure below, upper signaling (or upper layer signaling) may be a signal transmission method or signal transmitted from a base station to a terminal using a downlink data channel of a physical layer, or from a terminal to a base station using an uplink data channel of a physical layer. For example, upper signaling (or upper layer signaling) may be referred to as RRC RRC signaling, PDCP signaling, or MAC (medium access control) control element (MAC control element; MAC CE), but is not limited thereto.

[0286] Hereinafter, in the present disclosure, when a terminal determines whether cooperative communication is applied, various methods may be used, such as, but not limited to, the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied having a specific format, or the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied including a specific indicator that indicates whether cooperative communication is applied, or the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied being scrambled with a specific RNTI, or the application of cooperative communication is assumed in a specific section indicated to a higher layer. For the convenience of the following description, the case in which the terminal receives a PDSCH to which cooperative communication is applied based on conditions similar to the above will be referred to as the NC-JT case. That is, the NC-JT case in the present disclosure includes reception of a PDSCH to which cooperative communication is applied, and whether cooperative communication is applied can be identified based on at least one or a combination of at least one of the above-described conditions / methods.

[0287] In the present disclosure, determining the priority between A and B may be referred to in various ways, such as selecting a higher priority according to a predetermined priority rule and performing an action corresponding to it, or omitting or dropping an action for a lower priority.

[0288] In the present disclosure below, the above examples are described through a number of embodiments, but they are not independent and one or more embodiments may be applied simultaneously or in combination.

[0289] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. Hereinafter, a base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, a gNB, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. Although embodiments of the present disclosure are described below using a 5G system as an example, embodiments of the present disclosure may be applied to other communication systems having similar technical backgrounds or channel types. For example, LTE or LTE-A mobile communication and mobile communication technologies developed after 5G may be included here. Therefore, embodiments of the present disclosure may be applied to other communication systems with some modifications without significantly departing from the scope of the present disclosure as determined by a person skilled in the art. One embodiment of the present disclosure may be applied to an FDD, TDD, or XDD system, but is not limited thereto.

[0290] Additionally, when describing the present disclosure, detailed descriptions of related functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Furthermore, the terms described below are defined based on the functions of the present disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the contents of this specification.

[0291] In the following description of the present disclosure, upper layer signaling may be signaling corresponding to at least one or a combination of one or more of the following signaling.

[0292] - MIB (Master Information Block)

[0293] - SIB (System Information Block) or SIB

[0294] - RRC (Radio Resource Control)

[0295] - MAC (Medium Access Control) CE (Control Element)

[0296] In addition, L1 signaling may be signaling corresponding to at least one or a combination of one or more signaling methods using the following physical layer channels or signaling.

[0297] - PDCCH (Physical Downlink Control Channel)

[0298] - DCI (Downlink Control Information)

[0299] - UE-specific DCI

[0300] - Group common DCI

[0301] - Common DCI

[0302] - Scheduling DCI (e.g. DCI used for scheduling downlink or uplink data)

[0303] - Non-scheduled DCI (e.g. DCI not intended for scheduling downlink or uplink data)

[0304] - PUCCH (Physical Uplink Control Channel)

[0305] - UCI (Uplink Control Information)

[0306] [DCI Length Alignment]

[0307] To reduce the complexity of blind decoding of NR terminals, the number of DCI formats of different lengths is fixed. For example, DCI formats scrambled with C-RNTI are allowed up to three different lengths, and a total of four DCI format lengths are allowed. For example, a terminal can monitor up to three different lengths of DCI using C-RNTI, and can additionally monitor one additional DCI (length) using a special purpose RNTI (e.g., SFI-RNTI, INT-RNTI, etc.). This can be called DCI size budget (or DCI budget 3+1).

[0308] If the number of DCI formats of different lengths monitored by an NR terminal exceeds the DCI size budget, the terminal can adjust the lengths of some DCI formats to be the same. This series of processes can be referred to as DCI length alignment. An example of the DCI length alignment process can be as follows.

[0309] Step 0:

[0310] ● Determine the DCI format 0_0 monitored in the common search space (CSS) according to section 7.3.1.1.1 of 3GPP standard document TS38.212. Here, is the size of the initial UL BWP.

[0311] ● Determine the DCI format 1_0 monitored in the common search space according to section 7.3.1.2.1 of 3GPP standard document TS38.212. Here is the size of CORESET 0 if CORESET 0 is configured in the cell, or the size of the initial DL BWP if CORESET 0 is not configured in the cell.

[0312] ● If DCI format 0_0 is monitored in the common search space and the number of information bits before padding of DCI format 0_0 is less than the length of DCI format 1_0 monitored in the common search space for scheduling of the same serving cell, some zero padding bits are generated for DCI format 0_0 to convert its length to be the same as DCI format 1_0.

[0313] ● If DCI format 0_0 is monitored in the common search space and the number of information bits before padding of DCI format 0_0 is greater than the length of DCI format 1_0 monitored in the common search space for scheduling the same serving cell, the most significant bits (MSBs) of the frequency domain resource allocation field in DCI format 0_0 are truncated so that the size of DCI format 0_0 becomes the same as the size of DCI format 1_0.

[0314] Step 1:

[0315] ● Size of Active UL BWP Determine the DCI format 0_0 monitored in the UE specific search space (USS).

[0316] ● The size of Actove DL BWP Determine the DCI format 1_0 monitored in the UE-specific search space.

[0317] ● For a UE configured with supplementaryUplink in the cell's ServingCellConfig, if PUSCH is configured to be transmitted on both the SUL and non-SUL of the cell and the number of information bits of DCI format 0_0 in the UE-specific search space for SUL is not equal to the number of information bits of DCI format 0_0 in the UE-specific search space for non-SUL, some zero padding bits are generated for the smaller DCI format 0_0 until its length is equal to that of the larger DCI format 0_0.

[0318] ● If DCI format 0_0 is monitored in the UE-specific search space and the number of information bits of DCI format 0_0 before padding is less than the length of DCI format 1_0 monitored in the UE-specific search space scheduled for the same serving cell, some zero padding bits are generated for DCI format 0_0.

[0319] ● If DCI format 1_0 is monitored in the UE-specific search space and the number of information bits of DCI format 1_0 before padding is less than the length of DCI format 0_0 monitored in the UE-specific search space scheduled for the same serving cell, zeros are added to adjust the length of DCI format 1_0 until it becomes equal to DCI format 0_0.

[0320] Step 2:

[0321] ● DCI format 0_1 ​​monitored in the search space per UE is determined according to section 7.3.1.1.2 of 3GPP standard document TS38.212.

[0322] ● DCI format 1_1 monitored in the search space per UE is determined according to section 7.3.1.2.2 of 3GPP standard document TS38.212.

[0323] ● For a UE configured with supplementaryUplink in the cell's ServingCellConfig, if PUSCH is configured to be transmitted on both the SUL and non-SUL of the cell and the number of information bits in the DCI format 0_1 ​​of the SUL is not equal to the number of information bits in the DCI format 0_1 ​​of the non-SUL, the smaller DCI format 0_1 ​​is converted to the same length as the larger DCI format 0_1 ​​by adding 0 to it.

[0324] ● If the size of DCI format 0_1 ​​monitored in the search space per UE is the same as the size of DCI format 0_0 / 1_0 monitored in another search space per UE, add a 1-bit padding bit of '0' to DCI format 0_1.

[0325] ● If the size of DCI format 1_1 monitored in the search space per UE is the same as the size of DCI format 0_0 / 1_0 monitored in another search space per UE, add a 1-bit padding bit of '0' to DCI format 1_1.

[0326] Step 2A:

[0327] ● Determine the DCI format 0_2 to be monitored in the search space per UE according to section 7.3.1.1.3 of 3GPP standard document TS38.212.

[0328] ● Determine the DCI format 1_2 to be monitored in the search space per UE according to section 7.3.1.2.3 of 3GPP standard document TS38.212.

[0329] ● For UEs configured with supplementaryUplink in the cell's ServingCellConfig, if PUSCH is configured to be transmitted on both SUL and non-SUL of the cell and the number of information bits in DCI format 0_2 of SUL is not equal to the number of information bits in DCI format 0_2 of non-SUL, padding is added by adding '0' for the smaller DCI format 0_2 until its length is equal to that of the larger DCI format 0_2.

[0330] Step 3:

[0331] ● The DCI length alignment procedure is complete if both of the following conditions are met:

[0332] ○ If the total number of different DCI sizes to be monitored in the cell is 4 or less

[0333] ○ If the total number of different DCI sizes configured with C-RNTI in the cell is 3 or less

[0334] Step 4:

[0335] ● Otherwise

[0336] Step 4A:

[0337] ● Remove padding bits (if any) introduced in step 2.

[0338] ● Determine the DCI format 1_0 monitored in the terminal-specific search space according to section 7.3.1.2.1 of 3GPP standard document TS38.212. Here is the size of CORESET 0 if CORESET 0 is configured in the cell, or the size of the initial DL BWP if CORESET 0 is not configured in the cell.

[0339] ● Determine the DCI format 0_0 monitored in the terminal-specific search space according to section 7.3.1.1.1 of 3GPP standard document TS38.212. Here, is the size of the initial UL BWP.

[0340] ● If the length (before padding) of DCI format 0_0 monitored in the UE-specific search space is less than the number of information bits of DCI format 1_0 monitored in the UE-specific search space to schedule the same serving cell, add some zero padding bits in DCI format 0_0 until the length becomes the same as that monitored in DCI format 1_0.

[0341] ● If the number of information bits of DCI format 0_0 monitored in the search space per UE (before truncation) is greater than the number of information bits of DCI format 1_0 monitored in the search space per UE for scheduling the same serving cell, some bits of the MSB (Most Significant Bit) of the frequency domain resource allocation field of DCI format 0_0 are reduced. The size of DCI format 0_0 is converted to be the same as the size of DCI format 1_0 monitored in the search space per UE.

[0342] Step 4B:

[0343] ● If the total number of other DCI lengths to be monitored in the cell after applying the above steps is 4 or more, or the total number of other DCI lengths with C-RNTI configured is 3 or more,

[0344] ○ If the number of information bits of DCI format 0_2 before padding is less than the length of DCI format 1_2 for scheduling the same serving cell, a certain number of zero padding bits are added to DCI format 0_2 until the length becomes the same as that of DCI format 1_2.

[0345] ○ If the number of information bits of DCI format 1_2 before padding is less than the length of DCI format 0_2 for scheduling the same serving cell, a certain number of zero padding bits are added to DCI format 1_2 until the length becomes the same as that of DCI format 0_2.

[0346] Step 4C:

[0347] ● If the total number of other DCI lengths to be monitored in the cell is 4 or more after applying the above steps, or the total number of other DCI lengths configured with C-RNTI is 3 or more

[0348] ○ If the number of information bits of DCI format 0_1 ​​before padding is less than the length of DCI format 1_1 for scheduling the same serving cell, a certain number of zero padding bits are added to DCI format 0_1 ​​until the length becomes the same as that of DCI format 1_1.

[0349] ○ If the number of information bits of DCI format 1_1 before padding is less than the length of DCI format 0_1 ​​for scheduling the same serving cell, a certain number of zero padding bits are added to DCI format 1_1 until the length becomes the same as that of DCI format 0_1.

[0350] FIG. 11 is a diagram illustrating an example of a DCI length alignment method applicable to one embodiment of the present disclosure. The DCI length alignment method illustrated in FIG. 11 is a more specific example of an example of the DCI length alignment process described above, and more specific details can be found in the description described above. In the following description, it can be understood that the terminal having a DCI format length means that the terminal is set to monitor a DCI format of the corresponding length.

[0351] Referring to Fig. 11(a), after step 3, the lengths of different DCI formats that the terminal has are the lengths for DCI format 0_0 and DCI format 1_0 monitored by CSS (Size A), the lengths for DCI format 0_0 and DCI format 1_0 monitored by USS (Size B), the length of DCI format 0_1 ​​(Size C), the length of DCI format 1_1 (Size D), the length of DCI format 0_2 (Size E), and the length of DCI format 1_2 (Size F). Therefore, the terminal has the lengths of up to six different DCI formats.

[0352] Referring to FIG. 11(b), in step 4-A, the length (Size B) for DCI format 0_0 and DCI format 1_0 that the terminal monitors in the USS can be adjusted to be the same as the length (Size A) for DCI format 0_0 and DCI format 1_0 that the terminal monitors in the CSS. Accordingly, Size B can be adjusted to satisfy Size A = Size B. Accordingly, after step 4-A, the terminal can have DCI formats with up to five different lengths.

[0353] Referring to Fig. 11(c), in step 4-B, the length (Size E) of DCI format 0_2 and the length (Size F) of DCI format 1_2 can be made identical. If the length (Size F) of DCI format 1_2 is longer, the length (Size E) of DCI format 0_2 can be converted to the length (Size F) of DCI format 1_2. That is, Size F = Size E can be satisfied. Therefore, after step 4-B, the terminal can have up to four DCI formats with different lengths.

[0354] Referring to Fig. 11(d), in step 4-C, the length (Size C) of DCI format 0_1 ​​and the length (Size D) of DCI format 1_1 can be adjusted to be the same. If the length (Size D) of DCI format 1_1 is longer, the length (Size C) of DCI format 0_1 ​​can be converted to the length (Size D) of DCI format 1_1. That is, Size D = Size C can be satisfied. Therefore, after step 4-C, the terminal can have up to three DCI formats with different lengths.

[0355] In this way, a terminal can have up to three different DCI formats (scrambled with C-RNTI).

[0356] Example 1: Length alignment of DCI format 0_0 and DCI format 1_0 monitored by USS

[0357] Referring back to step 4-A described above, in step 4-A, the padding bit added in the previous step 2 is removed.

[0358] In step 4-A, the terminal determines the length of DCI format 1_0 monitored by the USS. The number of RBs included in CORESET0, not the number of RBs included in the active DL BWP, and the number of RBs included in the initial DL BWP were used. For example, in DCI format 1_0 can be used to determine the length of the FDRA field. The length of the FDRA field is am.

[0359] In step 4-A, the terminal determines the length of DCI format 0_0 monitored by the USS. The number of RBs included in the initial UL BWP was used, not the number of RBs included in the active UL BWP.

[0360] And, in step 4-A, the terminal adjusted the length of DCI format 0_0 to be the same as DCI format 1_0 based on the length of DCI format 1_0 monitored by USS.

[0361] Therefore, the purpose of step 4-A may be to match the lengths of DCI format 0_0 and DCI format 1_0 monitored by the USS with the lengths of DCI format 0_0 and DCI format 1_0 monitored by the CSS. After step 4-A, since the lengths of DCI format 0_0 and DCI format 1_0 monitored by the UE in the USS and DCI format 0_0 and DCI format 1_0 monitored by the UE in the CSS become the same, the number of DCI formats with different lengths may be reduced. Therefore, it is possible that the DCI budget 3+1 can be satisfied.

[0362] Meanwhile, the frequency range in which NR can operate includes FR1 and FR2 and can be defined as shown in Table 16. The values ​​of the frequency range are examples and are not limited thereto.

[0363] [Table 16]

[0364]

[0365] DCI (e.g., DCI format 1_0) may contain a 'ChannelAccess-CPext' field and corresponding Reserved bits (for FR2-2). However, the purpose of step 4-A may not be achieved due to the Reserved bits field introduced in the FR2_2 band. This will be described in more detail later.

[0366] In Example 1, a method is proposed that enables the length of DCI format 0_0 and DCI format 1_0 monitored in USS to be the same as that of DCI format 0_0 and DCI format 1_0 monitored in CSS, even when a Reserved bits field introduced in the FR2_2 band exists.

[0367] FIG. 12 is a diagram illustrating a problem of a DCI length alignment method applicable to one embodiment of the present disclosure. Detailed descriptions of the same content as FIG. 11 are omitted.

[0368] Referring to FIG. 12, for example, in step 4-A of DCI length alignment, it is assumed that the lengths of DCI format 0_0 and DCI format 1_0 monitored by the USS are different from the lengths of DCI format 0_0 and DCI format 1_0 monitored by the CSS (FIG. 12(b)). In this case, the number of DCI formats with different lengths that the terminal monitors after step 4-A is 6. The number of DCI formats with different lengths that the terminal monitors after step 4-B is 5 (FIG. 12(c)). The number of DCI formats with different lengths that the terminal monitors after step 4-C is 4 (FIG. 12(d)). Therefore, the terminal may not be able to have at most 3 different (C-RNTI scrambled) DCI formats. Therefore, the DCI size budget is not satisfied.

[0369] Specifically, we will examine the problems in Step 4-A.

[0370] Referring to 3GPP standard document TS38.212 v17.5.0, some fields of DCI format 1_0 are described as in Table 17.

[0371] [Table 17]

[0372]

[0373] Referring to Table 17, the length of the ChannelAccess-CPext field can be 0 bits or 2 bits. Here, the determination of 0 bits or 2 bits can be determined by the upper layer signal “ChannelAccessMode2-r17”. From the terminal’s perspective, there may be ambiguity regarding the length of DCI format 1_0 before receiving the upper layer signal. For example, assuming that ChannelAccessMode2-r17 is not set, the terminal regards the length of the ChannelAccess-CPext field as 0 bits, but assuming that ChannelAccessMode2-r17 is set, the terminal may regard the length of the ChannelAccess-CPext field as 2 bits. Therefore, two DCI format 1_0 lengths can be derived for the terminal. That is, since the length of the ChannelAccess-CPext field varies depending on whether ChannelAccessMode2-r17 is set, the length of DCI format 1_0 expected by the terminal may be two. Additionally, as previously explained, since the length of DCI format 0_0 is aligned to be the same as the length of DCI format 1_0, the length of DCI format 0_0 can also be two. Therefore, in order for the terminal to receive DCI format 1_0 or DCI format 0_0, it must monitor DCI with at least two lengths.

[0374] Note that the above-described ambiguity may not exist in USS. Since USS is configured by a higher layer signal (e.g., an RRC signal), when a terminal performs monitoring in USS, the terminal can (in advance) obtain information about whether ChannelAccessMode2-r17 is set. However, the above-described ambiguity may exist in CSS. DCI formats 1_0 to 0_0 monitored in CSS may be monitored prior to receiving a higher layer signal (e.g., an RRC signal). For example, DCI format 1_0 with CRC scrambled with SI-RNTI is used to obtain scheduling information of PDSCH that transmits system information, DCI format 1_0 with CRC scrambled with P-RNTI is used to obtain control information for paging-related information, DCI format 1_0 with CRC scrambled with RA-RNTI or MsgB-RNTI is used to receive PDSCH that schedules RACH response (RAR. message 2 or message B) after RACH transmission, and DCI format 1_0 with CRC scrambled with TC-RNTI can be used to receive a response to message 3 transmission in the RACH process.

[0375] To eliminate the above ambiguity in CSS, the Reserved bits field is defined in DCI format 1_0. The purpose of the Reserved bits may be to ensure that the length of DCI format 1_0 monitored by CSS does not change depending on a higher layer signal (e.g., an RRC signal). Therefore, since ChannelAccess-CPext in DCI format 1_0 can be 0 bits or 2 bits, if ChannelAccess-CPext is 0 bits, the Reserved bits can be 2 bits, and if ChannelAccess-CPext is 2 bits, the Reserved bits can be 0 bits. That is, the sum of the length of ChannelAccess-CPext and the length of the Reserved bits can always be maintained as 2 bits. Therefore, the terminal can determine the length of one DCI format 1_0.

[0376] The above reserved bits are added only to DCI format 1_0 monitored by CSS. As mentioned above, for DCI format 1_0 monitored by USS, since a higher layer signal (e.g., RRC signal) has already been received, the length of one DCI format 1_0 can be determined.

[0377] That is, the DCI format 1_0 monitored in CSS may have 2 bits in the Reserved bits field, but the DCI format 1_0 monitored in USS may have 0 bits (or may not be included) in the Reserved bits field. That is, the size of the Reserved bits of the DCI format 1_0 monitored in CSS and the size of the Reserved bits of the DCI format 1_0 monitored in USS may be different. This will affect the result of step 4-A.

[0378] Let's look at step 4-A of DCI length alignment again.

[0379] The purpose of Step 4-A is to align the length of DCI format 0_0 and DCI format 1_0 monitored by USS with the length of DCI format 0_0 and DCI format 1_0 monitored by CSS. The reason why the length of DCI format 1_0 monitored by USS and DCI format 1_0 monitored by CSS are different is due to the different lengths of the FDRA fields. Therefore, in order to have the same length of the FDRA field, for DCI format 1_0 monitored by USS, The number of RBs included in CORESET0, not the number of RBs included in the active DL BWP, and the number of RBs included in the initial DL BWP can be used.

[0380] However, as explained above, the DCI format 1_0 monitored by the USS may have a Reserved bits field of 0 bits, and the DCI format 1_0 monitored by the CSS may have a Reserved bits field of 2 bits in length. As described above, the Reserved bits field is set only for the CSS, so for example, if ChannelAccess-CPext is 0 bits, the DCI format 1_0 monitored by the CSS has a 2-bit Reserved bits field, but the DCI format 1_0 monitored by the USS does not include the Reserved bits field, so a length difference of at least 2 bits may occur between the DCI format 1_0 monitored by the USS and the DCI format 1_0 monitored by the CSS.

[0381] Therefore, even if step 4-A is performed, the lengths of DCI format 0_0 and DCI format 1_0 monitored in the USS obtained by the terminal and the lengths of DCI format 0_0 and DCI format 1_0 monitored in the CSS may not be the same. Therefore, the number of different DCI lengths may not be reduced.

[0382] According to one embodiment of the present disclosure, the above-described problem can be solved. The effects of one embodiment of the present disclosure are not limited thereto, and other effects not mentioned can be derived based on the detailed description of the present disclosure.

[0383] According to one embodiment of the present disclosure, at least one or a combination of at least one of the following methods may be used. For the same content as the DCI length alignment method described above in the following methods, a detailed description thereof will be omitted, and reference may be made to the DCI length alignment method described above.

[0384] In the first method, in step 4-A, the terminal can change the length of the Reserved bits field of the DCI format 1_0 monitored by the CSS to be the same as the length of the Reserved bits field of the DCI format 1_0 monitored by the USS. That is, the terminal can change the length of the Reserved bits field of the DCI format 1_0 monitored by the CSS to 0 bits.

[0385] More specifically, the first method is as follows.

[0386] The terminal can obtain the lengths of DCI format 1_0 and DCI format 0_0 monitored by CSS in step 0 of DCI length alignment. In this step, for example, DCI format 1_0 may include a Reserved bits field, and its length (of the Reserved bits field) may be 0 to 2 bits.

[0387] In step 3, if the DCI size budget is not satisfied, the terminal can perform step 4. Step 4-A is as follows.

[0388] In step 4-A, the padding bit added in the previous step 2 is removed.

[0389] In step 4-A, the terminal determines the length of DCI format 1_0 monitored by the USS. The number of RBs included in CORESET0, not the number of RBs included in the active DL BWP, is used, and the number of RBs included in the initial DL BWP is used. For example, in DCI format 1_0, It can be used to determine the length of the FDRA field. The length of the FDRA field is am.

[0390] In step 4-A, the terminal determines the length of DCI format 0_0 monitored by the USS. It uses the number of RBs included in the initial UL BWP, not the number of RBs included in the active UL BWP.

[0391] In step 4-A, the terminal may change the length of the Reserved bits field of DCI format 1_0 monitored in CSS to 0 bits.

[0392] And, in step 4-A, the terminal adjusts the length of DCI format 0_0 to be the same as DCI format 1_0 based on the length of DCI format 1_0 monitored by USS.

[0393] According to the present method, the lengths of DCI format 0_0 and DCI format 1_0 monitored in the USS and the lengths of DCI format 0_0 and DCI format 1_0 monitored in the CSS can be made the same after the above step 4-A.

[0394] The advantages of the first method are as follows. Since the terminal sets the DCI format 0_0 to DCI format 1_0 monitored by the USS through a higher layer signal (e.g., an RRC signal), the terminal may have no ambiguity regarding the length of the DCI format 1_0 monitored by the CSS. Accordingly, the DCI size can be reduced by removing the Researved bits field from the DCI format 1_0 monitored by the CSS.

[0395] In the second method, in step 4-A, the terminal can change the length of the Reserved bits field of the DCI format 1_0 monitored by the USS to be the same as the length of the Reserved bits field of the DCI format 1_0 monitored by the CSS. That is, the length of the Reserved bits field of the DCI format 1_0 monitored by the USS can be changed to 0 bits or 2 bits, which is the length of the Reserved bits field of the DCI format 1_0 monitored by the CSS.

[0396] More specifically, the second method is as follows.

[0397] The terminal can obtain the lengths of DCI format 1_0 and DCI format 0_0 monitored by CSS in step 0 of DCI length alignment. In this step, for example, DCI format 1_0 may include a Reserved bits field, and the length (of the Reserved bits field) may be 0 to 2 bits.

[0398] The terminal can obtain the lengths of DCI format 1_0 and DCI format 0_0 monitored by the USS in the first step of DCI length alignment. In this step, the reserved bits in DCI format 1_0 monitored by the USS may be 0 bits.

[0399] In step 3, if the DCI size budget is not satisfied, the terminal can perform step 4. Step 4-A is as follows.

[0400] In step 4-A, the padding bit added in the previous step 2 is removed.

[0401] In step 4-A, the terminal determines the length of DCI format 1_0 monitored by the USS. The number of RBs included in CORESET0, not the number of RBs included in the active DL BWP, is used, and the number of RBs included in the initial DL BWP is used. For example, in DCI format 1_0, can be used to determine the length of the FDRA field. The length of the FDRA field is am.

[0402] In step 4-A, the terminal determines the length of DCI format 0_0 monitored by the USS. It uses the number of RBs included in the initial UL BWP, not the number of RBs included in the active UL BWP.

[0403] In step 4-A, the terminal can align the Reserved bits field of the DCI format 1_0 monitored by the USS to the same length as the Reserved bits field of the DCI format 1_0 monitored by the CSS. That is, if the Reserved bits field of the DCI format 1_0 monitored by the CSS is X bits (X=0 or 2), the Reserved bits field of the DCI format 1_0 monitored by the USS can also be determined to be X bits.

[0404] And, in step 4-A, the terminal adjusts the length of DCI format 0_0 to be the same as DCI format 1_0 based on the length of DCI format 1_0 monitored by USS.

[0405] According to the present method, the lengths of DCI format 0_0 and DCI format 1_0 monitored in the USS and the lengths of DCI format 0_0 and DCI format 1_0 monitored in the CSS can be made the same after the above step 4-A.

[0406] The advantage of the second method is that the lengths of DCI format 0_0 and DCI format 1_0 monitored in the CSS do not change. In an environment where a UE operating according to the present disclosure (new UE) and a UE maintaining the existing operation (legacy UE) coexist, if the lengths of DCI format 0_0 and DCI format 1_0 monitored in the CSS change, the lengths assumed by the new UE and the lengths assumed by the legacy UE become different. Therefore, the base station may need to transmit DCI formats corresponding to the two lengths, respectively, in order to convey downlink control information to the new UE and the legacy UE. However, according to the second method, since the lengths of DCI format 0_0 and DCI format 1_0 monitored in the CSS do not change, the new UE and the legacy UE can monitor downlink control information with the same length in the CSS. That is, the base station can transmit downlink control information of one length to the new UE and the legacy UE in the CSS. In other words, from the base station's perspective, there may be no need to configure DCIs of separate lengths for the new UE and the legacy UE in the CSS.

[0407] The third method is that the length of the Reserved bits field in the DCI format 1_0 monitored in CSS can always be fixed to 0 bits. That is, in DCI length alignment, the terminal can regard the length of the Reserved bits field in the DCI format 1_0 monitored in CSS as 0 bits. That is, since the length of the ChannelAccess-CPext field is 0 bits and / or 2 bits, the terminal can assume two lengths of the DCI format 1_0 monitored in CSS. In this case, in DCI length alignment, the lengths of the DCI format 0_0 and DCI format 1_0 monitored by the USS as a result of step 4-A and the lengths of the DCI format 0_0 and DCI format 1_0 monitored by CSS can be the same. For example, the length of the ChannelAccess-CPext field of DCI format 1_0 monitored by CSS and USS may be the same, 0 bits or 2 bits, in which case the length of DCI format 0_0 and DCI format 1_0 monitored by USS and the length of DCI format 0_0 and DCI format 1_0 monitored by CSS may be the same.

[0408] As a fourth method, the length of the ChannelAccess-CPext field can always be assumed to be 2 bits, and the length of the Reserved bits field can always be fixed to 0 bits. That is, in DCI length alignment, the terminal can regard the length of the ChannelAccess-CPext field and the length of the Reserved bits field of the DCI format 1_0 monitored in CSS as 0 bits. This can be applied simultaneously to the DCI format 1_0 monitored in CSS and the DCI format 1_0 monitored in USS. That is, since the ChannelAccess-CPext field has a single length, the terminal can assume a single length for the DCI format 1_0 monitored in CSS.

[0409] For example, if the length of the ChannelAcess-CPext field is 2 bits, the terminal can determine the LBT (listen-before-talk) type (or channel access type, channel access procedure type) for channel access based on the 2 bits. According to TS38.212, the LBT type indicated by the 2 bits can be obtained from the following Table 18.

[0410] [Table 18]

[0411]

[0412] Here, for example, if the terminal does not receive the upper layer signal ChannelAccessMode2-r17, the LBT type may not be determined through the value in Table 18. For example, in the case of a terminal where ChannelAccessMode2-r17 is not set, the 2-bit ChannelAccess-CPext field may be '00' but no separate action may be required. That is, the 2-bit '00' here is interpreted as maintaining the length of the ChannelAccess-CPext field to 2 bits. However, in the case of a terminal where ChannelAccessMode2-r17 is set, if the 2-bit ChannelAccess-CPext field is '00', a specific LBT type is determined. Therefore, the field may be interpreted differently for each terminal. In the case of the DCI format monitored by CSS, since one or more terminals may receive it simultaneously, it may be desirable to interpret it identically.

[0413] According to one embodiment, the table indicated by the 2 bit ChannelAccess-CPext field may be as shown in Table 19 below.

[0414] [Table 19]

[0415]

[0416] Referring to Table 19, if the 2 bits ChannelAccess-CPext of the DCI format is '00', the terminal that receives the DCI format can interpret the ChannelAccess-CPext field in the same way. That is, the terminal can interpret the ChannelAccess-CPext field of '00' as reserved regardless of whether the upper layer signal ChannelAccessMode2-r17 is received. This may be because the 2 bits ChannelAccess-CPext is assigned 'reserved' as the Channel access type corresponding to '00'.

[0417] In the description of one embodiment of the present disclosure described above, the DCI formats may be a DCI format scrambled with a C-RNTI. In the case of a DCI format scrambled with another RNTI, the following method may be used.

[0418] For example, it can be assumed that the DCI format 1_0 scrambled with C-RNTI monitored in CSS and the DCI format 1_0 scrambled with C-RNTI monitored in USS are determined according to the above-described embodiment.

[0419] The length of the DCI format 1_0 scrambled with an RNTI other than the C-RNTI monitored by CSS may need to be aligned with the length of the DCI format 1_0 scrambled with the C-RNTI monitored by CSS. To achieve this, the length of the Reserved bits field in the DCI format 1_0 scrambled with an RNTI other than the C-RNTI monitored by CSS may be adjusted.

[0420] The length of DCI format 1_0 scrambled with an RNTI other than the C-RNTI monitored by the USS may need to be matched to the length of DCI format 1_0 scrambled with the C-RNTI monitored by the USS. To achieve this, the length of the Reserved bits field in DCI format 1_0 scrambled with an RNTI other than the C-RNTI monitored by the USS may be adjusted.

[0421] [MC-DCI related]

[0422] In the present disclosure, one DCI may be a Single-DCI or may be in one DCI format, and multiple DCIs may be Multi-DCI or may be in multiple DCI formats. In the present disclosure, one DCI may be one PDCCH and / or may be transmitted and received through one PDCCH, and multiple DCIs may be in multiple PDCCHs and / or may be transmitted and received through multiple PDCCHs.

[0423] In general, a terminal receives one DCI, and the one DCI may include scheduling information for one cell. For example, in the case of DCI format 0_0 / 0_1 / 0_2, one PUSCH may be scheduled for one uplink cell. In addition, in the case of DCI format 1_0 / 1_1 / 1_2, one PDSCH may be scheduled for one downlink cell. Here, the scheduled cell may be indicated by the CIF (carrier indication field) of the DCI format.

[0424] However, according to this method, when PDSCH or PUSCH is scheduled in each of multiple cells, multiple DCIs must be transmitted and received. Therefore, a large amount of DCI overhead may occur. To reduce DCI overhead, one DCI can schedule PDSCH or PUSCH for each of multiple cells. This can be conveniently referred to as MC-DCI (Multi-cell DCI). In the present disclosure, MC-DCI can be one DCI that schedules PDSCH and / or PUSCH for each of multiple cells.

[0425] The cells that can be scheduled in MC-DCI can be configured by a higher layer. For example, it is assumed that MC-DCI can schedule cell 0, cell 1, cell 2, and cell 3 simultaneously. When the terminal receives the MC-DCI, the terminal can receive scheduling information for cell 0, cell 1, cell 2, and cell 3. That is, the terminal can obtain scheduling information for cell 0, cell 1, cell 2, and cell 3 from the MC-DCI. For example, it can be configured from a higher layer that MC-DCI can schedule cell 0, cell 1, cell 2, and cell 3. Here, the scheduling information can include time domain resource allocation (TDRA) information and / or frequency domain resource allocation information (FDRA) through which data channels (PDSCH for downlink, PUSCH for uplink) are transmitted and received in each cell. Accordingly, the terminal can obtain scheduling information of each cell through the MC-DCI and transmit and receive data channels to and from each cell.

[0426] A base station may not be able to schedule all cells configured for a terminal under certain circumstances. Scheduling may not be possible for at least some of the multiple cells configured by the base station for a terminal. For example, a base station may configure four cells (e.g., Cell 0, Cell 1, Cell 2, and Cell 3) for scheduling with MC-DCI for a terminal, but some of these cells may not be schedulable, for example, due to scheduling by other terminals, poor channel conditions, or other various reasons. In this case, the base station must be able to indicate to the terminal the scheduling cells among the pre-configured cells scheduled with MC-DCI. In other words, the base station must be able to indicate to the terminal which of the multiple cells configured to be scheduled with MC-DCI will be (actually) scheduled.

[0427] This may be directed based on one of the following two methods, or a combination of at least one of the following two methods.

[0428] In the first method, the terminal can obtain information indicating cells co-scheduled with the current MC-DCI among the preset cells (e.g., cell 0, cell 1, cell 2, cell 3) from the MC-DCI. That is, among the multiple cells configured to be scheduled with the MC-DCI, one or more cells (actually) co-scheduled through the MC-DCI can be identified based on the MC-DCI. More specifically, the base station can configure a table including cells co-scheduled for the terminal. For example, the rows of this table can have unique indexes. The index of each row can include the indexes of cells that are co-scheduled. For example, {cell 0, cell 1} can be configured for row 0, {cell 2, cell 3} for row 1, and {cell 0, cell 1, cell 2, cell 3} for row 2. An example of a table set for a terminal can be found in Table 20.

[0429] [Table 20]

[0430]

[0431] The terminal can obtain a value indicating the index of the row from the MC-DCI. Accordingly, the terminal can determine a cell to be scheduled based on the value. For example, the MC-DCI can include information about the index of the row, and the terminal can identify cells to be scheduled simultaneously based on the index of the row obtained from the MC-DCI and the table. For example, if row 0 is indicated from the MC-DCI, the terminal can identify that cell 0 and cell 1 are cells to be scheduled simultaneously. For example, if row 1 is indicated from the MC-DCI, the terminal can identify that cell 2 and cell 3 are cells to be scheduled simultaneously. For example, if row 2 is indicated from the MC-DCI, the terminal can identify that cell 0, cell 1, cell 2, and cell 3 are cells to be scheduled simultaneously.

[0432] In the present disclosure, a table is set for a mapping relationship between cells scheduled simultaneously (or indices of cells scheduled) and indices indicated from DCI, and a cell to be scheduled can be identified based on the table and the indices indicated from DCI.

[0433] Although the present disclosure has described an embodiment in which cells to be scheduled simultaneously are identified based on the index of a row of a table, the present disclosure is not limited thereto, and for example, cells to be scheduled simultaneously may also be identified based on the index of a column of a table, in which case the rows in the above-described embodiment may be replaced with columns.

[0434] As a second method, the terminal can make a decision based on the FDRA field of MC-DCI.

[0435] FIG. 13 is a diagram illustrating an example in which MC-DCI according to one embodiment of the present disclosure includes multiple FDRA fields.

[0436] Referring to FIG. 13, MC-DCI (1300) may include multiple FDRA fields. And each FDRA field may have a corresponding cell. That is, when cells that can be simultaneously scheduled by MC-DCI (1300) are set as cell 0 (1320), cell 1 (1321), cell 2 (1322), and cell 3 (1323), it may include an FDRA field (1310) for cell 0, an FDRA field (1311) for cell 1, an FDRA field (1312) for cell 2, and an FDRA field (1313) for cell 3. Based on the value of the FDRA field, it may be determined whether each cell is scheduled. Cells scheduled based on the value of the FDRA field may be called actually co-scheduled cells.

[0437] The FDRA field can be divided into valid and invalid values. A valid value may be one in which a frequency domain assignment corresponding to the value in the FDRA field exists. Conversely, an invalid value may be one in which a frequency domain assignment corresponding to the value in the FDRA field does not exist.

[0438] For example, valid and invalid values ​​are described based on FDRA type-0. FDRA type-0 is a method of indicating RBs (or RBGs) to be scheduled based on a bitmap. Here, each bit may have corresponding RBs (or RBGs). If the bit is '1', the corresponding RBs (or RBGs) may be scheduled, and if the bit is '0', the corresponding RBs (or RBGs) may not be scheduled. Therefore, if at least one bit is '1', it may be determined as a valid value, and if all bits are '0', it may be determined as an invalid value.

[0439] For example, valid and invalid values ​​are explained based on FDRA type-1. FDRA type-1 is a method of indicating RBs to be scheduled based on RIV (resource indication value). Here, FDRA type-1 can schedule consecutive RBs in the frequency domain. FDRA type-1 can indicate the index of the starting RB and the number of consecutive RBs. The RIV value can be one of 0, 1,…, N*(N+1) / 2 -1. Here, N is the number of RBs included in the frequency domain. Therefore, if the RIV value is one of 0, 1,…, N*(N+1) / 2 -1, it can be determined as a valid value, and a value greater than or equal to N*(N+1) / 2 can be determined as an invalid value.

[0440] FIG. 14 is a diagram illustrating an example of cell determination that is actually scheduled simultaneously based on multiple FDRA fields included in MC-DCI according to one embodiment of the present disclosure.

[0441] Referring to FIG. 14, MC-DCI (1400) may include FDRA fields (e.g., FDRA field (1410) for cell 0, FDRA field (1411) for cell 1, FDRA field (1412) for cell 2, FDRA field (1413) for cell 3) for each of a plurality of cells (e.g., cell 0 (1420), cell 1 (1421), cell 2 (1422), cell 3 (1423)). The terminal may determine the validity of each FDRA field. For example, the terminal may determine that the FDRA field (1410) for cell 0, the FDRA field (1412) for cell 2, and the FDRA field (1413) for cell 3 are valid, and that the FDRA field (1411) for cell 1 is invalid. In this case, cell 1, which is determined to be invalid, may be an unscheduled cell, and cells 0, 2, and 3, which are determined to be valid, may be scheduled cells.

[0442] The terminal can determine the length of MC-DCI in different ways, depending on the two methods mentioned above. These are as follows.

[0443] For the first method, the length of MC-DCI can be determined as follows.

[0444] The length of the MC-DCI scheduling the downlink may be determined based on the RRC configuration of the active downlink BWPs of the cells that can be simultaneously scheduled within the cell set. The length of the MC-DCI scheduling the downlink may be the same for the active downlink BWPs of all simultaneously schedulable cell combinations, and may be equal to the largest length among the active downlink BWPs of all simultaneously schedulable cell combinations determined by the simultaneously schedulable cell combination table.

[0445] The length of the MC-DCI for scheduling the uplink may be determined according to the RRC configuration of the active uplink BWPs of the cells that can be simultaneously scheduled within the cell set. The length of the MC-DCI for scheduling the uplink is the same for the active uplink BWPs of all simultaneously schedulable cell combinations, and may be equal to the largest length among the active uplink BWPs of all simultaneously schedulable cell combinations determined by the simultaneously schedulable cell combination table.

[0446] For the second method, the length of MC-DCI can be determined as follows.

[0447] The length of the MC-DCI scheduling the downlink can be determined based on the RRC configuration of the active downlink BWP of all cells within the cell set. The length of the MC-DCI scheduling the uplink can be determined based on the RRC configuration of the active uplink BWP of all cells within the cell set.

[0448] In both of the above methods, the terminal can determine the length of MC-DCI according to the RRC configuration of the active BWP.

[0449] Hereinafter, a method for aligning the length of MC-DCI according to one embodiment of the present disclosure is described.

[0450] Example 2: DCI format 0_X to DCI format 1_X length alignment

[0451] According to the 3GPP NR standard, new DCI formats, DCI format 0_X and DCI format 1_X, may be introduced. The characteristic of the DCI format 0_X is that one DCI format 0_X schedules a PUSCH for each of multiple cells, and the characteristic of the DCI format 1_X is that one DCI format 1_X schedules a PDSCH for each of multiple cells. When the newly introduced DCI format 0_X or DCI format 1_X is introduced, a new DCI length alignment method may be required.

[0452] According to an embodiment of the present disclosure, the following DCI alignment method may be considered.

[0453] Step 0:

[0454] ● Determine the DCI format 0_0 monitored in the common search space (CSS) according to section 7.3.1.1.1 of 3GPP standard document TS38.212. Here, is the size of the initial UL BWP.

[0455] ● Determine the DCI format 1_0 monitored in the common search space according to section 7.3.1.2.1 of 3GPP standard document TS38.212. Here is the size of CORESET 0 if CORESET 0 is configured in the cell, or the size of the initial DL BWP if CORESET 0 is not configured in the cell.

[0456] ● If DCI format 0_0 is monitored in the common search space and the number of information bits before padding of DCI format 0_0 is less than the length of DCI format 1_0 monitored in the common search space for scheduling of the same serving cell, some zero padding bits are generated for DCI format 0_0 to convert its length to be the same as DCI format 1_0.

[0457] ● If DCI format 0_0 is monitored in the common search space and the number of information bits before padding of DCI format 0_0 is greater than the length of DCI format 1_0 monitored in the common search space for scheduling the same serving cell, the most significant bits (MSBs) of the frequency domain resource allocation field in DCI format 0_0 are truncated so that the size of DCI format 0_0 becomes the same as the size of DCI format 1_0.

[0458] Step 1:

[0459] ● Size of Active UL BWP Determine the DCI format 0_0 monitored in the UE-specific search space (UE-specific search space, USS).

[0460] ● The size of Active DL BWP Determine the DCI format 1_0 monitored in the UE-specific search space.

[0461] ● For a UE configured with supplementaryUplink in the cell's ServingCellConfig, if PUSCH is configured to be transmitted on both the SUL and non-SUL of the cell and the number of information bits of DCI format 0_0 in the UE-specific search space for SUL is not equal to the number of information bits of DCI format 0_0 in the UE-specific search space for non-SUL, some zero padding bits are generated for the smaller DCI format 0_0 until its length is equal to that of the larger DCI format 0_0.

[0462] ● If DCI format 0_0 is monitored in the UE-specific search space and the number of information bits of DCI format 0_0 before padding is less than the length of DCI format 1_0 monitored in the UE-specific search space scheduled for the same serving cell, some zero padding bits are generated for DCI format 0_0.

[0463] ● If DCI format 1_0 is monitored in the UE-specific search space and the number of information bits of DCI format 1_0 before padding is less than the length of DCI format 0_0 monitored in the UE-specific search space scheduled for the same serving cell, zeros are added to adjust the length of DCI format 1_0 until it becomes equal to DCI format 0_0.

[0464] Step 2:

[0465] ● DCI format 0_1 ​​monitored in the search space per UE is determined according to section 7.3.1.1.2 of 3GPP standard document TS38.212.

[0466] ● DCI format 1_1 monitored in the search space per UE is determined according to section 7.3.1.2.2 of 3GPP standard document TS38.212.

[0467] ● For a UE configured with supplementaryUplink in the cell's ServingCellConfig, if PUSCH is configured to be transmitted on both the SUL and non-SUL of the cell and the number of information bits in the DCI format 0_1 ​​of the SUL is not equal to the number of information bits in the DCI format 0_1 ​​of the non-SUL, the smaller DCI format 0_1 ​​is converted to the same length as the larger DCI format 0_1 ​​by adding 0 to it.

[0468] ● If the size of DCI format 0_1 ​​monitored in the search space per UE is the same as the size of DCI format 0_0 / 1_0 monitored in another search space per UE, add a 1-bit padding bit of '0' to DCI format 0_1.

[0469] ● If the size of DCI format 1_1 monitored in the search space per UE is the same as the size of DCI format 0_0 / 1_0 monitored in another search space per UE, add a 1-bit padding bit of '0' to DCI format 1_1.

[0470] Step 2A:

[0471] ● Determine the DCI format 0_2 to be monitored in the search space per UE according to section 7.3.1.1.3 of 3GPP standard document TS38.212.

[0472] ● Determine the DCI format 1_2 to be monitored in the search space per UE according to section 7.3.1.2.3 of 3GPP standard document TS38.212.

[0473] ● For UEs configured with supplementaryUplink in the cell's ServingCellConfig, if PUSCH is configured to be transmitted on both SUL and non-SUL of the cell and the number of information bits in DCI format 0_2 of SUL is not equal to the number of information bits in DCI format 0_2 of non-SUL, padding is added by adding '0' for the smaller DCI format 0_2 until its length is equal to that of the larger DCI format 0_2.

[0474] Step 2B:

[0475] ● Determine the DCI format 0_X monitored in the search space for each UE.

[0476] ● Determine the DCI format 1_X monitored in the search space for each UE.

[0477] ● For UEs configured with supplementaryUplink in the cell's ServingCellConfig, if PUSCH is configured to be transmitted on both SUL and non-SUL of the cell and the number of information bits in DCI format 0_X of SUL is not equal to the number of information bits in DCI format 0_X of non-SUL, padding is added by adding '0' for the smaller DCI format 0_X until its length is equal to that of the larger DCI format 0_X.

[0478] ● If the size of DCI format 0_X monitored in the search space per UE is the same as the size of DCI format 0_0 / 1_0 / 0_1 / 1_1 monitored in another search space per UE, add a 1-bit padding bit of '0' to DCI format 0_X.

[0479] ● If the size of DCI format 1_X monitored in the search space per UE is the same as the size of DCI format 0_0 / 1_0 / 0_1 / 1_1 monitored in another search space per UE, add a '0' 1-bit padding bit to DCI format 1_X.

[0480] In one embodiment, 1 bit may be added to the two items to make the length of DCI format 0_X / 1_X different from the length of DCI format 0_0 / 1_0 / 0_1 / 1_1. Here, DCI format 0_0 / 1_0 / 0_1 / 1_1 and length are used, but some DCI formats (e.g., DCI format 0_1 / 1_1 or DCI format 0_0 / 1_0) may be used. That is, at least one of DCI formats 0_0 / 0_1 / 1_1 may be used. Or, at least one of DCI formats other than 0_0 / 0_1 / 1_1 may be used.

[0481] Step 3:

[0482] ● The DCI length alignment procedure is complete if both of the following conditions are met:

[0483] ○ If the total number of different DCI sizes to be monitored in the cell is 4 or less

[0484] ○ If the total number of different DCI sizes configured with C-RNTI in the cell is 3 or less

[0485] Step 4:

[0486] ● Otherwise

[0487] Step 4A:

[0488] ● Remove padding bits (if any) introduced in step 2.

[0489] ● Determine the DCI format 1_0 monitored in the terminal-specific search space according to section 7.3.1.2.1 of 3GPP standard document TS38.212. Here is the size of CORESET 0 if CORESET 0 is configured in the cell, or the size of the initial DL BWP if CORESET 0 is not configured in the cell.

[0490] ● Determine the DCI format 0_0 monitored in the terminal-specific search space according to section 7.3.1.1.1 of 3GPP standard document TS38.212. Here, is the size of the initial UL BWP.

[0491] ● If the length (before padding) of DCI format 0_0 monitored in the UE-specific search space is less than the number of information bits of DCI format 1_0 monitored in the UE-specific search space to schedule the same serving cell, add some zero padding bits in DCI format 0_0 until the length becomes the same as that monitored in DCI format 1_0.

[0492] ● If the number of information bits of DCI format 0_0 monitored in the search space per UE (before truncation) is greater than the number of information bits of DCI format 1_0 monitored in the search space per UE for scheduling the same serving cell, some bits of the MSB (Most Significant Bit) of the frequency domain resource allocation field of DCI format 0_0 are reduced. The size of DCI format 0_0 is converted to be the same as the size of DCI format 1_0 monitored in the search space per UE.

[0493] Step 4B:

[0494] ● If the total number of other DCI lengths to be monitored in the cell after applying the above steps is 4 or more, or the total number of other DCI lengths with C-RNTI configured is 3 or more,

[0495] ○ If the number of information bits of DCI format 0_2 before padding is less than the length of DCI format 1_2 for scheduling the same serving cell, a certain number of zero padding bits are added to DCI format 0_2 until the length becomes the same as that of DCI format 1_2.

[0496] ○ If the number of information bits of DCI format 1_2 before padding is less than the length of DCI format 0_2 for scheduling the same serving cell, a certain number of zero padding bits are added to DCI format 1_2 until the length becomes the same as that of DCI format 0_2.

[0497] Step 4C:

[0498] ● If the total number of other DCI lengths to be monitored in the cell is 4 or more after applying the above steps, or the total number of other DCI lengths configured with C-RNTI is 3 or more

[0499] ○ If the number of information bits of DCI format 0_1 ​​before padding is less than the length of DCI format 1_1 for scheduling the same serving cell, a certain number of zero padding bits are added to DCI format 0_1 ​​until the length becomes the same as that of DCI format 1_1.

[0500] ○ If the number of information bits of DCI format 1_1 before padding is less than the length of DCI format 0_1 ​​for scheduling the same serving cell, a certain number of zero padding bits are added to DCI format 1_1 until the length becomes the same as that of DCI format 0_1.

[0501] Step 4D:

[0502] ● If the total number of other DCI lengths to be monitored in the cell is 4 or more after applying the above steps, or the total number of other DCI lengths configured with C-RNTI is 3 or more

[0503] ○ If the number of information bits of DCI format 0_X before padding is less than the length of DCI format 1_X for scheduling the same serving cell, a certain number of zero padding bits are added to DCI format 0_X until the length becomes the same as that of DCI format 1_X.

[0504] ○ If the number of information bits of DCI format 1_X before padding is less than the length of DCI format 0_X for scheduling the same serving cell, a certain number of zero padding bits are added to DCI format 1_X until the length becomes the same as that of DCI format 0_X.

[0505] If the number of DCI formats (scrambled with C-RNTI) of different lengths obtained using the above DCI length alignment method exceeds 3, the terminal may determine that the DCI budget has been exceeded. In this case, the terminal may additionally align the lengths of the DCI formats of different lengths to be the same using at least one of the following methods.

[0506] For reference, steps 2B and 4D are for determining the length of DCI format 0_X to DCI format 1_X. There may be multiple cells that DCI format 0_X to DCI format 1_X can schedule simultaneously. Therefore, steps 2B to 4D may be performed for all of the multiple cells that are scheduled simultaneously. For example, when DCI format 0_X to DCI format 1_X can schedule cell 0 and cell 1 simultaneously, steps 2B to 4D may be performed when aligning the DCI length for cell 0, and steps 2B to 4D may be performed when aligning the DCI length for cell 1. However, steps 2B to 4D may not be performed when aligning the DCI length for other cells, for example, cell 2. Additionally, when checking the DCI budget in cell 2, DCI format 0_X or DCI format 1_X may be excluded.

[0507] Alternatively, steps 2B to 4D may be performed for one DCI among multiple cells that are scheduled simultaneously. For example, if DCI format 0_X to DCI format 1_X can be scheduled simultaneously in cell 0 and cell 1, steps 2B to 4D may be performed in only one cell among cell 0 and cell 1. This cell may be referred to as a reference cell. That is, the cell in which steps 2B to 4D are performed may be a reference cell. For example, let the reference cell be cell 0. Steps 2B to 4D may be performed when aligning the DCI length for cell 0. However, steps 2B to 4D may not be performed when aligning the DCI length for cell 1. In addition, when checking the DCI budget in cell 1, DCI format 0_X to DCI format 1_X may be excluded. And, for other cells, for example, steps 2B to 4D may not be performed when aligning the DCI length for cell 2. Also, when checking the DCI budget in cell 2, DCI format 0_X to DCI format 1_X may be excluded.

[0508] An example of a method for determining a reference cell is as follows. If there is a cell among the cells that can be scheduled simultaneously through DCI format 0_X to DCI format 1_X that monitors the DCI (e.g., DCI format 0_X to DCI format 1_X), the cell may be a reference cell. If there is no cell among the cells that are scheduled simultaneously, the cell with the lowest index may be a reference cell.

[0509] According to one embodiment of the present disclosure, the terminal can match the uplink DCI format and downlink DCI format of the first length and the uplink DCI format and downlink DCI format of the second length to the same length.

[0510] Here, {uplink DCI format and downlink DCI format of the first length, uplink DCI format and downlink DCI format of the second length}

[0511] {DCI format 0_1 ​​and DCI format 1_1, DCI format 0_2 and DCI format 1_2}, or

[0512] {DCI format 0_1 ​​and DCI format 1_1, DCI format 0_X and DCI format 1_X}, or

[0513] {DCI format 0_X and DCI format 1_X, DCI format 0_2 and DCI format 1_2} can be used.

[0514] The terminal may convert a DCI format of a shorter length into a DCI format of a longer length based on the longer one between the first DCI format of a first length and the second DCI format of a second length. For example, (one or more) '0's may be added to the last bits of the DCI format of a shorter length (zero padding). Accordingly, DCI formats of different lengths may have the same length.

[0515] However, even if they have the same length, the terminal may need to determine whether the received DCI format is the first DCI format or the second DCI format. For example, a 1-bit indicator may be included to distinguish between uplink DCI formats and downlink DCI formats of the same length. For example, the indicator may always be located at the first most significant bit (MSB) of the uplink DCI format and the first most significant bit (MSB) of the downlink DCI format.

[0516] The terminal may include a 1-bit indicator in each of the first DCI format and the second DCI format to distinguish between the first DCI format and the second DCI format that are aligned to the same length. Consequently, the lengths of the first DCI format and the second DCI format may increase by 1 bit at the same time. The 1-bit indicator may be included in the same position in the first DCI format and the second DCI format. For example, it may be included in the most significant bit (MSB) or the least significant bit (LSB).

[0517] After completing DCI length alignment using the above method, the terminal can verify whether the DCI budget is satisfied. If there are three or fewer DCI formats with different lengths, the DCI budget is determined to be satisfied.

[0518] FIG. 15 is a diagram illustrating an example of the operation of a terminal and a base station according to one embodiment of the present disclosure. The method of FIG. 15 is for illustrative purposes only, and various modifications may be made to the method illustrated in the flowchart of FIG. 15 . For example, although illustrated as a series of steps, the various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.

[0519] Referring to FIG. 15, in operation 1501, the base station may transmit configuration information, and the terminal may receive the same. The configuration information may include information related to DCI length alignment. For example, it may include, but is not limited to, at least one of configuration information related to ChannelAccessMode2-r17 and USS.

[0520] In operation 1503, the terminal may perform operations related to DCI length alignment.

[0521] In operation 1505, the base station can transmit DCI, and the terminal can receive / monitor the DCI based on DCI length alignment. For example, if the terminal aligns the DCI length, the base station can also transmit the DCI according to the DCI length aligned by the terminal. The terminal can monitor the DCI of the length determined in the DCI alignment process in the set search space, and may not monitor DCI of a different length.

[0522] For more specific details on the operation of the terminal and base station illustrated in FIG. 15, refer to the description of the above-described embodiment. FIG. 16 is a diagram illustrating the structure of a terminal in a wireless communication system according to an embodiment of the present disclosure.

[0523] Referring to FIG. 16, the terminal may include a transceiver, which refers to a terminal receiving unit (1600) and a terminal transmitting unit (1610), a memory (not shown), and a terminal processing unit (1605), or a terminal control unit or processor). Depending on the communication method of the terminal described above, the transceiver units (1600, 1610), the memory, and the terminal processing unit (1605) of the terminal may operate. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more or fewer components than the components described above. In addition, the transceiver unit, the memory, and the processor may be implemented in the form of a single chip.

[0524] A transceiver unit can transmit and receive signals to and from a base station. The signals may include control information and data. To this end, the transceiver unit may include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. However, this is merely one embodiment of the transceiver unit, and the components of the transceiver unit are not limited to the RF transmitter and RF receiver.

[0525] Additionally, the transceiver can receive a signal through a wireless channel and output it to the processor, and transmit a signal output from the processor through the wireless channel.

[0526] Memory can store programs and data necessary for the terminal's operation. Furthermore, memory can store control information or data included in signals transmitted and received by the terminal. Memory can be comprised of a storage medium, such as ROM, RAM, a hard disk, CD-ROM, or DVD, or a combination of such storage media. Furthermore, there can be multiple memories.

[0527] Additionally, the processor can control a series of processes to enable the terminal to operate according to the aforementioned embodiments. For example, the processor can receive DCI consisting of two layers and control components of the terminal to simultaneously receive multiple PDSCHs. There may be multiple processors, and the processors can perform component control operations of the terminal by executing programs stored in memory.

[0528] FIG. 17 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0529] Referring to FIG. 17, the base station may include a transceiver, which refers to a base station receiver (1730) and a base station transmitter (1710), a memory (not shown), and a base station processor (1705), or a base station control unit or processor). According to the communication method of the base station described above, the transceiver (1700, 1710), the memory, and the base station processor (1705) of the base station may operate. However, the components of the base station are not limited to the examples described above. For example, the base station may include more or fewer components than the components described above. In addition, the transceiver, the memory, and the processor may be implemented in the form of a single chip.

[0530] The transceiver can transmit and receive signals with the terminal. Here, the signals may include control information and data. To this end, the transceiver may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. However, this is only one embodiment of the transceiver, and the components of the transceiver are not limited to the RF transmitter and RF receiver.

[0531] Additionally, the transceiver can receive a signal through a wireless channel and output it to the processor, and transmit the signal output from the processor through the wireless channel.

[0532] The memory can store programs and data necessary for the operation of the base station. Furthermore, the memory can store control information or data included in signals transmitted and received by the base station. The memory can be comprised of a storage medium, such as ROM, RAM, a hard disk, CD-ROM, or DVD, or a combination of such storage media. Furthermore, there can be multiple memories.

[0533] The processor can control a series of processes to enable the base station to operate according to the aforementioned embodiments of the present disclosure. For example, the processor can configure two layers of DCIs containing allocation information for multiple PDSCHs and control each component of the base station to transmit them. There may be multiple processors, and the processors can perform component control operations of the base station by executing programs stored in memory.

[0534] The 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.

[0535] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

[0536] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0537] Additionally, the program may be stored on an attachable storage device that is accessible via a communication network, such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device implementing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device implementing an embodiment of the present disclosure.

[0538] In the specific embodiments of the present disclosure described above, components included in the present disclosure are expressed singularly or plurally, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0539] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples to easily explain the technical contents of the present disclosure and to help the understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it will be apparent to those skilled in the art that other modifications based on the technical idea of ​​the present disclosure are possible. In addition, the above-mentioned embodiments can be combined and operated with each other as needed. For example, parts of one embodiment of the present disclosure and parts of another embodiment can be combined with each other to operate a base station and a terminal. For example, parts of the first embodiment and the second embodiment of the present disclosure can be combined with each other to operate a base station and a terminal. In addition, although the above-mentioned embodiments have been presented based on an FDD LTE system, other modifications based on the technical idea of ​​the above-mentioned embodiments can be implemented with other systems such as a TDD LTE system, a 5G or NR system.

[0540] Meanwhile, the order of description in the drawings explaining the method of the present disclosure does not necessarily correspond to the order of execution, and the order of precedence may be changed or executed in parallel.

[0541] Alternatively, the drawings illustrating the method of the present disclosure may omit some components and include only some components without detracting from the essence of the present disclosure.

[0542] In addition, the method of the present disclosure may be implemented by combining some or all of the contents included in each embodiment within a scope that does not harm the essence of the present disclosure.

[0543] Various embodiments of the present disclosure have been described above. The foregoing description of the present disclosure is for illustrative purposes only, and the embodiments of the present disclosure are not limited to the disclosed embodiments. Those skilled in the art will appreciate that the present disclosure can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present disclosure. The scope of the present disclosure is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present disclosure.

Claims

1. In a method performed by a terminal in a communication system, A step of receiving configuration information about a search space through upper layer signaling, wherein the search space includes a user equipment specific search space (USS) and a common search space (CSS); A step of performing DCI (downlink control information) size alignment, wherein the DCI size alignment includes setting the size of a reserved bits field of the DCI to be monitored in the USS to be equal to the size of a reserved bits field of the DCI to be monitored in the CSS; and A method comprising the step of performing PDCCH (physical downlink control channel) monitoring based on the above setting information and the DCI size alignment.

2. In paragraph 1, If configuration information for the channel access mode is received via the upper layer signaling: The size of the field indicating the channel access type of the DCI to be monitored in the above CSS is 2 bits. The size of the reserved bit field of DCI to be monitored in the above CSS is 0 bits, A method wherein the size of the reserved bit field of the DCI to be monitored in the above USS is set to 0 bits according to the DCI size alignment.

3. In paragraph 2, If the configuration information for the above channel access mode is not received via the upper layer signaling: The size of the field indicating the channel connection type of the DCI to be monitored in the above CSS is 0 bits. The size of the reserved bit field of DCI to be monitored in the above CSS is 2 bits, A method wherein the size of the reserved bit field of the DCI to be monitored in the above USS is set to 2 bits according to the DCI size alignment.

4. In paragraph 2, A method wherein the field indicating the setting information for the above channel access mode and the channel access type of the DCI to be monitored in the CSS is for FR (frequency range) 2-2.

5. In paragraph 1, A method wherein the DCI to be monitored in the above CSS and the DCI to be monitored in the above USS correspond to DCI format 1_0.

6. At the terminal of the communication system, Transmitter and receiver; and A processor coupled to the transceiver, the processor comprising: Receive configuration information about the search space through upper layer signaling; The above search space includes USS (user equipment specific search space) and CSS (common search space); Performing DCI (downlink control information) size alignment; wherein the DCI size alignment includes setting the size of a reserved bits field of the DCI to be monitored in the USS to be equal to the size of a reserved bits field of the DCI to be monitored in the CSS; and A terminal configured to perform PDCCH (physical downlink control channel) monitoring based on the above setting information and the DCI size alignment.

7. In paragraph 6, If configuration information for the channel access mode is received via the upper layer signaling: The size of the field indicating the channel access type of the DCI to be monitored in the above CSS is 2 bits. The size of the reserved bit field of DCI to be monitored in the above CSS is 0 bits, A terminal in which the size of the reserved bit field of the DCI to be monitored in the above USS is set to 0 bits according to the DCI size alignment.

8. In paragraph 7, If the configuration information for the above channel access mode is not received via the upper layer signaling: The size of the field indicating the channel connection type of the DCI to be monitored in the above CSS is 0 bits. The size of the reserved bit field of DCI to be monitored in the above CSS is 2 bits, A terminal in which the size of the reserved bit field of the DCI to be monitored in the above USS is set to 2 bits according to the DCI size alignment.

9. In paragraph 7, A terminal, wherein the field indicating the setting information for the above channel access mode and the channel access type of the DCI to be monitored in the above CSS is for FR (frequency range) 2-2.

10. In paragraph 6, The DCI to be monitored in the above CSS and the DCI to be monitored in the above USS correspond to DCI format 1_0.

11. In a method performed by a base station in a communication system, A step of transmitting configuration information about a search space through upper layer signaling, wherein the search space includes a user equipment specific search space (USS) and a common search space (CSS); and Comprising a step of transmitting a PDCCH (physical downlink control channel) related to the above setting information, The above PDCCH is related to DCI (downlink control information) size alignment, A method wherein the above DCI size alignment relates to setting the size of a reserved bits field of the DCI to be transmitted in the USS to be the same as the size of a reserved bits field of the DCI to be transmitted in the CSS.

12. In paragraph 11, If configuration information for the channel access mode is transmitted via the upper layer signaling: The size of the field indicating the channel access type of the DCI to be transmitted in the above CSS is 2 bits. The size of the reserved bit field of the DCI to be transmitted in the above CSS is 0 bits, A method wherein the size of the reserved bit field of the DCI to be transmitted in the above USS is 0 bits.

13. In paragraph 12, If the configuration information for the above channel access mode is not transmitted via the upper layer signaling: The size of the field indicating the channel connection type of DCI to be transmitted in the above CSS is 0 bits, The size of the reserved bit field of DCI to be transmitted in the above CSS is 2 bits, A method wherein the size of the reserved bit field of the DCI to be transmitted in the above USS is 2 bits.

14. In the base station of the communication system, Transmitter and receiver; and A processor coupled to the transceiver, the processor comprising: Transmitting configuration information about the search space via upper layer signaling; The above search space includes USS (user equipment specific search space) and CSS (common search space); and It is configured to transmit a PDCCH (physical downlink control channel) related to the above setting information, The above PDCCH is related to DCI (downlink control information) size alignment, The base station, wherein the above DCI size alignment relates to setting the size of the reserved bits field of the DCI to be transmitted in the USS to be the same as the size of the reserved bits field of the DCI to be transmitted in the CSS.

15. In paragraph 14, If configuration information for the channel access mode is transmitted via the upper layer signaling: The size of the field indicating the channel access type of the DCI to be transmitted in the above CSS is 2 bits. The size of the reserved bit field of the DCI to be transmitted in the above CSS is 0 bits, The size of the reserved bit field of the DCI to be transmitted in the above USS is 0 bits, If the configuration information for the above channel access mode is not transmitted via the upper layer signaling: The size of the field indicating the channel connection type of DCI to be transmitted in the above CSS is 0 bits, The size of the reserved bit field of DCI to be transmitted in the above CSS is 2 bits, A base station, wherein the size of the reserved bit field of the DCI to be transmitted in the above USS is 2 bits.

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