Method and device for transmitting and receiving demodulation reference signal in wireless 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 operations of a terminal and a base station in a wireless communication system. Specifically, the present disclosure relates to a method for transmitting and receiving a demodulation reference signal in a wireless communication system, and an apparatus capable of performing same. A method performed by a terminal according to one embodiment of the present disclosure comprises the steps of: transmitting capability information indicating that the terminal supports being configured for both (i) an enhanced demodulation-reference signal (DM-RS) and (ii) a downlink control information (DCI) format 1_3; receiving the DCI format 1_3 through a physical downlink control channel (PDCCH); and receiving a physical downlink shared channel (PDSCH) DM-RS for a PDSCH scheduled by the DCI format 1_3, wherein the PDSCH DM-RS is related to the enhanced DM-RS.

Description

Method and device for transmitting and receiving a demodulation reference signal in a wireless communication system

[0001] The present disclosure relates to the operation of a terminal and a base station in a wireless communication system. Specifically, the present disclosure relates to a method for transmitting and receiving a demodulation reference signal in a wireless communication system, and a device capable of performing the same.

[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] The disclosed embodiment seeks to provide a device and method capable of effectively providing a service in a mobile 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] A method performed by a terminal in a communication system according to one embodiment of the present disclosure comprises the steps of: transmitting capability information indicating that the terminal supports configuring both (i) an enhanced DM-RS (demodulation-reference signal) and (ii) a DCI (downlink control information) format 1_3; receiving the DCI format 1_3 via a physical downlink control channel (PDCCH); and receiving a PDSCH DM-RS for a PDSCH (physical downlink shared channel) scheduled by the DCI format 1_3, wherein the PDSCH DM-RS can be associated with the enhanced DM-RS.

[0012] According to one embodiment of the present disclosure, the enhanced DM-RS may be related to: for DM-RS type 1, the maximum number of DM-RS ports for a single symbol DM-RS is 8 and the maximum number of DM-RS ports for a double symbol DM-RS is 16; and for DM-RS type 2, the maximum number of DM-RS ports for a single symbol DM-RS is 12 and the maximum number of DM-RS ports for a double symbol DM-RS is 24.

[0013] According to one embodiment of the present disclosure, the DCI format 1_3 includes an antenna port field, and reception of the PDSCH DM-RS can be based on the antenna port field.

[0014] According to one embodiment of the present disclosure, the method further includes a step of receiving, after transmitting the capability information, a configuration related to the enhanced DM-RS and a configuration related to the DCI format 1_3 through upper layer signaling, wherein the reception of the DCI format 1_3 and the reception of the PDSCH DM-RS can be performed after receiving the configuration related to the enhanced DM-RS and the configuration related to the DCI format 1_3.

[0015] According to one embodiment of the present disclosure, the settings related to the enhanced DM-RS may be included in DMRS-DownlinkConfig.

[0016] A terminal of a communication system according to one embodiment of the present disclosure comprises a transceiver; and a processor connected to the transceiver, wherein the processor is configured to: transmit capability information indicating that the terminal supports both (i) an enhanced DM-RS (demodulation-reference signal) and (ii) a DCI (downlink control information) format 1_3; receive the DCI format 1_3 via a PDCCH (physical downlink control channel); and receive a PDSCH DM-RS for a PDSCH (physical downlink shared channel) scheduled by the DCI format 1_3, wherein the PDSCH DM-RS can be associated with the enhanced DM-RS.

[0017] According to one embodiment of the present disclosure, the enhanced DM-RS may be related to: for DM-RS type 1, the maximum number of DM-RS ports for a single symbol DM-RS is 8 and the maximum number of DM-RS ports for a double symbol DM-RS is 16; and for DM-RS type 2, the maximum number of DM-RS ports for a single symbol DM-RS is 12 and the maximum number of DM-RS ports for a double symbol DM-RS is 24.

[0018] According to one embodiment of the present disclosure, the DCI format 1_3 includes an antenna port field, and reception of the PDSCH DM-RS can be based on the antenna port field.

[0019] According to one embodiment of the present disclosure, in claim 6, the processor is configured to: receive, through higher layer signaling, a configuration related to the enhanced DM-RS and a configuration related to the DCI format 1_3 after transmitting the capability information, and the reception of the DCI format 1_3 and the reception of the PDSCH DM-RS can be performed after receiving the configuration related to the enhanced DM-RS and the configuration related to the DCI format 1_3.

[0020] According to one embodiment of the present disclosure, the settings related to the enhanced DM-RS may be included in DMRS-DownlinkConfig.

[0021] In a communication system according to one embodiment of the present disclosure, a base station includes the steps of: receiving capability information from a terminal indicating that the terminal supports configuring both (i) an enhanced DM-RS (demodulation-reference signal) and (ii) a DCI (downlink control information) format 1_3; transmitting the DCI format 1_3 to the terminal via a PDCCH (physical downlink control channel); and transmitting a PDSCH DM-RS for a PDSCH (physical downlink shared channel) scheduled by the DCI format 1_3 to the terminal, wherein the PDSCH DM-RS can be associated with the enhanced DM-RS.

[0022] According to one embodiment of the present disclosure, the enhanced DM-RS may be related to: for DM-RS type 1, the maximum number of DM-RS ports for a single symbol DM-RS is 8 and the maximum number of DM-RS ports for a double symbol DM-RS is 16; and for DM-RS type 2, the maximum number of DM-RS ports for a single symbol DM-RS is 12 and the maximum number of DM-RS ports for a double symbol DM-RS is 24.

[0023] According to one embodiment of the present disclosure, the method further includes: after receiving the capability information, transmitting, to the terminal, through higher layer signaling, a configuration related to the enhanced DM-RS and a configuration related to the DCI format 1_3, wherein reception of the DCI format 1_3 and reception of the PDSCH DM-RS can be performed after receiving the configuration related to the enhanced DM-RS and the configuration related to the DCI format 1_3.

[0024] A base station of a communication system according to one embodiment of the present disclosure comprises a transceiver; and a processor connected to the transceiver, wherein the processor is configured to: receive capability information from the terminal indicating that the terminal supports configuration for both (i) an enhanced DM-RS (demodulation-reference signal) and (ii) a downlink control information (DCI) format 1_3; transmit the DCI format 1_3 to the terminal via a physical downlink control channel (PDCCH); and transmit a PDSCH DM-RS for a physical downlink shared channel (PDSCH) scheduled by the DCI format 1_3 to the terminal, wherein the PDSCH DM-RS can be associated with the enhanced DM-RS.

[0025] According to one embodiment of the present disclosure, the enhanced DM-RS may be related to: for DM-RS type 1, the maximum number of DM-RS ports for a single symbol DM-RS is 8 and the maximum number of DM-RS ports for a double symbol DM-RS is 16; and for DM-RS type 2, the maximum number of DM-RS ports for a single symbol DM-RS is 12 and the maximum number of DM-RS ports for a double symbol DM-RS is 24.

[0026] The various embodiments of the present disclosure described above are only some of the preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of the various embodiments of the present disclosure can be derived and understood by a person having ordinary skill in the art based on the detailed description to be described below.

[0027] The disclosed embodiment provides a device and method capable of effectively providing a service in a mobile communication system.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] FIG. 6 is a diagram illustrating a case in which a terminal can have multiple PDCCH monitoring positions within a slot in a wireless communication system according to one embodiment of the present disclosure, through Span.

[0035] FIG. 7 is a diagram illustrating an example of base station beam allocation according to TCI state settings in a wireless communication system according to one embodiment of the present disclosure.

[0036] FIG. 8 is a diagram illustrating an example of a TCI state allocation method for a PDCCH in a wireless communication system according to one embodiment of the present disclosure.

[0037] FIG. 9 is a diagram illustrating a TCI indication MAC CE signaling structure for PDCCH DMRS in a wireless communication system according to one embodiment of the present disclosure.

[0038] FIG. 10 is a diagram illustrating an example of a control resource set and a beam setting of a search space in a wireless communication system according to one embodiment of the present disclosure.

[0039] FIG. 11 is a diagram illustrating an example of frequency axis resource allocation of PDSCH in a wireless communication system according to one embodiment of the present disclosure.

[0040] FIG. 12 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.

[0041] FIG. 13 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.

[0042] FIG. 14 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.

[0043] FIG. 15 is a diagram showing the operation of a terminal in a wireless communication system according to one embodiment of the present disclosure.

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

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

[0046] FIG. 18 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0047] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0048] 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 ensure that the gist of the present disclosure is conveyed more clearly without obscuring it by omitting unnecessary explanations.

[0049] 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.

[0050] 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 may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout the specification.

[0051] 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.

[0052] At this time, it will be understood that each block of the processing flowchart drawings and combinations of the flowchart drawings can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flowchart block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flowchart block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0053] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0054] 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.

[0055] Wireless communication systems are evolving from providing voice-oriented services in the early days to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as 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.

[0056] 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.

[0057] 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).

[0058] eMBB aims to provide data transmission rates that are significantly higher than those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must be able to 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.

[0059] At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide the 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.

[0060] Finally, URLLC refers to cellular-based wireless communication services used for specific mission-critical purposes. Examples include remote control of robots or machinery, industrial automation, unmanned aerial vehicles (UAVs), remote health care, and emergency alerts. Therefore, URLLC communications must offer extremely low latency and high reliability. For example, URLLC-enabled services must meet air interface latency requirements of less than 0.5 milliseconds and a packet error rate (PER) of 10-5 or lower. Therefore, for URLLC-enabled services, 5G systems must provide shorter Transmit Time Intervals (TTIs) than other services, while simultaneously allocating extensive resources in the frequency band to ensure communication link reliability.

[0061] 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.

[0062] [NR time-frequency resources]

[0063] Below, the frame structure of the 5G system is described in more detail with reference to drawings.

[0064] 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.

[0065] 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).

[0066] 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.

[0067] 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 the subcarrier spacing setting value μ = 0 (204) and μ = 1 (205) 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.

[0068] [Table 1]

[0069]

[0070] [Bandwidth Part (BWP)]

[0071] Next, the bandwidth part (BWP) setting in the 5G communication system will be explained in detail with reference to the drawing.

[0072] 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.

[0073] 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 the following information for each bandwidth portion.

[0074] [Table 2]

[0075]

[0076] 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).

[0077] 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.

[0078] The settings for the bandwidth supported by the above 5G can be used for various purposes.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] [Bandwidth Part (BWP) Change]

[0084] 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.

[0085] 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 follows, for example:

[0086] [Table 3]

[0087]

[0088] 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.

[0089] 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.

[0090] 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).

[0091] [PDCCH: DCI related]

[0092] Next, we will specifically explain downlink control information (DCI) in the 5G system.

[0093] 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.

[0094] 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.

[0095] 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).

[0096] 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 following information.

[0097] [Table 4]

[0098]

[0099] 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 following information.

[0100] [Table 5]

[0101]

[0102]

[0103] 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 following information.

[0104] [Table 6]

[0105]

[0106] 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 following information.

[0107] [Table 7]

[0108]

[0109] [PDCCH: CORESET, REG, CCE, Search Space]

[0110] Below, the downlink control channel in a 5G communication system will be described in more detail with reference to drawings.

[0111] 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.

[0112] 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 within one slot (420) in the time axis. The control regions (401, 402) can be set to specific frequency resources (403) within the entire UE bandwidth part (410) in the frequency axis. The time axis can be set to one or more OFDM symbols, which can 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.

[0113] 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.

[0114] [Table 8]

[0115]

[0116] 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.

[0117] Figure 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.

[0118] Referring to FIG. 5, the basic unit of time and frequency resources constituting the control channel can be referred to as a REG (Resource Element Group, 503), and the REG (503) can be defined as 1 OFDM symbol (501) on the time axis and 1 PRB (Physical Resource Block, 502) on the frequency axis, i.e., 12 subcarriers. The base station can concatenate REGs (503) to form a downlink control channel allocation unit.

[0119] 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.

[0120] 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 in FIG. 5A, 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.

[0121] 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.

[0122] 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.

[0123] [Table 9]

[0124]

[0125]

[0126] 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.

[0127] 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.

[0128] 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.

[0129] - 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

[0130] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0131] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0132] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0133] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0134] 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.

[0135] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0136] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0137] The RNTIs specified may follow the definitions and uses below.

[0138] C-RNTI (Cell RNTI): For terminal-specific PDSCH scheduling purposes

[0139] TC-RNTI (Temporary Cell RNTI): For terminal-specific PDSCH scheduling purposes

[0140] CS-RNTI (Configured Scheduling RNTI): Used for terminal-specific PDSCH scheduling that is set semi-statically.

[0141] RA-RNTI (Random Access RNTI): Used for PDSCH scheduling in the random access phase.

[0142] P-RNTI (Paging RNTI): Used for scheduling PDSCH where paging is transmitted.

[0143] SI-RNTI (System Information RNTI): Used for scheduling PDSCH where system information is transmitted.

[0144] INT-RNTI (Interruption RNTI): Used to indicate whether pucturing is in progress for PDSCH.

[0145] TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to indicate power control commands for PUSCH.

[0146] TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to indicate power control commands for PUCCH.

[0147] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to indicate power control commands for SRS.

[0148] The aforementioned specified DCI formats may follow the definitions below.

[0149] [Table 10]

[0150]

[0151] 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.

[0152] [Mathematical Formula 1]

[0153]

[0154] - L: Integration level

[0155] - n CI : Carrier Index

[0156] - N CCE,p : Total number of CCEs existing within the control region p

[0157] - : slot index

[0158] - : Number of PDCCH candidates for aggregation level L

[0159] - : PDCCH candidate index of aggregation level L

[0160] - i = 0, … , L-1

[0161] -

[0162] - n RNTI : Terminal identifier

[0163] The value can be 0 for a common search space.

[0164] 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.

[0165] In 5G, since multiple search space sets can be configured with different parameters (e.g., parameters in Table 8), 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.

[0166] When a terminal has multiple PDCCH monitoring positions within a slot, it can perform a terminal capability report for each subcarrier interval, and at this time, the concept of Span can be used. A Span refers to consecutive symbols within a slot in which the terminal can monitor a PDCCH, and each PDCCH monitoring position is within one Span. A Span can be expressed as (X, Y), where x refers to the minimum number of symbols that must be spaced between the first symbols of two consecutive Spans, and Y refers to the number of consecutive symbols in which the PDCCH can be monitored within one Span. In this case, the terminal can monitor the PDCCH in the section from the first symbol of the Span to Y symbols within the Span.

[0167] FIG. 6 is a diagram illustrating a case in which a terminal in a wireless communication system can have multiple PDCCH monitoring positions within a slot through Span.

[0168] Span can be (X,Y) = (7,4), (4,3), (2,2), and each of these three cases is represented by (6-00), (6-05), and (6-10) in Fig. 6. For example, (6-00) represents a case where there are two Spans that can be expressed as (7,4) within a slot. The interval between the first symbols of the two Spans is represented as X=7, and the PDCCH monitoring position can exist within a total of Y=3 symbols from the first symbol of each Span, and search spaces 1 and 2 each exist within Y=3 symbols. As another example, (6-05) represents a case where there are three Spans that can be expressed as (4,3) within a slot, and the interval between the second and third Spans is X'=5 symbols, which is larger than X=4.

[0169] [QCL, TCI state]

[0170] In a wireless communication system, one or more different antenna ports (or one or more channels, signals, and combinations thereof, but for convenience, they will be referred to as different antenna ports in the following description of the present disclosure) can be associated with each other by QCL (Quasi co-location) settings as shown in [Table 11] below. The TCI state is to notify the QCL relationship between the PDCCH (or PDCCH DMRS) and other RSs or channels. When a reference antenna port A (reference RS #A) and another target antenna port B (target RS #B) are QCLed with each other, it means that the terminal is allowed to apply some or all of the large-scale channel parameters estimated at the antenna port A to the channel measurement from the antenna port B. QCL may need to relate different parameters depending on the situation, such as 1) time tracking affected by average delay and delay spread, 2) frequency tracking affected by Doppler shift and Doppler spread, 3) radio resource management (RRM) affected by average gain, and 4) beam management (BM) affected by spatial parameters. Accordingly, NR supports four types of QCL relationships, as shown in Table 11 below.

[0171] [Table 11]

[0172]

[0173] The above spatial RX parameter may collectively refer to some or all of various parameters, such as Angle of arrival (AoA), Power Angular Spectrum (PAS) of AoA, Angle of departure (AoD), PAS of AoD, transmit / receive channel correlation, transmit / receive beamforming, and spatial channel correlation.

[0174] The above QCL relationship can be set to the terminal through the RRC parameters TCI-State and QCL-Info as shown in Table 12 below. Referring to Table 12, the base station can set one or more TCI states to the terminal and inform the RS referencing the ID of the TCI state, i.e., up to two QCL relationships (qcl-Type1, qcl-Type2) for the target RS. At this time, each QCL information (QCL-Info) included in the above TCI state includes the serving cell index and BWP index of the reference RS indicated by the corresponding QCL information, the type and ID of the reference RS, and the QCL type as shown in Table 11 above.

[0175] [Table 12]

[0176]

[0177] FIG. 7 is a diagram illustrating an example of base station beam allocation according to TCI state settings. Referring to FIG. 7, the base station can transmit information on N different beams to the terminal through N different TCI states. For example, in case of N=3 as shown in FIG. 7, the base station can notify that antenna ports referencing different TCI states 700, 705, or 710 have different spatial Rx parameters, i.e., are associated with different beams, by setting the qcl-Type2 parameter included in three TCI states (700, 705, 710) to be associated with CSI-RS or SSB corresponding to different beams and to QCL type D.

[0178] Tables 13-1 to 13-5 below show valid TCI state settings according to target antenna port type.

[0179] Table 13-1 shows valid TCI state settings when the target antenna port is a CSI-RS for tracking (TRS). The TRS refers to an NZP CSI-RS with no repetition parameter set and trs-Info set to true among CSI-RSs. Setting 3 in Table 13-1 can be used for aperiodic TRS.

[0180] [Table 13-1] Valid TCI state settings when the target antenna port is CSI-RS for tracking (TRS)

[0181]

[0182] Table 13-2 shows valid TCI state settings when the target antenna port is a CSI-RS for CSI. The CSI-RS for CSI refers to an NZP CSI-RS in which a parameter indicating repetition (e.g., repetition parameter) is not set among the CSI-RSs and trs-Info is not set to true.

[0183] [Table 13-2] Valid TCI state settings when the target antenna port is CSI-RS for CSI

[0184]

[0185] Table 13-3 shows valid TCI state settings when the target antenna port is CSI-RS for beam management (BM, synonymous with CSI-RS for L1 RSRP reporting). The CSI-RS for BM refers to an NZP CSI-RS in which the repetition parameter is set to On or Off among CSI-RSs and trs-Info is not set to true.

[0186] [Table 13-3] Valid TCI state settings when the target antenna port is CSI-RS for BM (for L1 RSRP reporting)

[0187]

[0188] Table 13-4 shows the valid TCI state settings when the target antenna port is PDCCH DMRS.

[0189] [Table 13-4] Valid TCI state settings when the target antenna port is PDCCH DMRS

[0190]

[0191] Table 13-5 shows the valid TCI state settings when the target antenna port is PDSCH DMRS.

[0192] [Table 13-5] Valid TCI state settings when the target antenna port is PDSCH DMRS

[0193]

[0194] A representative QCL configuration method according to Tables 13-1 to 13-5 above is to operate by setting the target antenna port and reference antenna port for each step as "SSB" -> "TRS" -> "CSI-RS for CSI, or CSI-RS for BM, or PDCCH DMRS, or PDSCH DMRS." Through this, it is possible to link statistical characteristics that can be measured from SSB and TRS to each antenna port to assist the terminal's reception operation.

[0195] [PDCCH: TCI state related]

[0196] Specifically, the TCI state combinations applicable to the PDCCH DMRS antenna port are as shown in Table 14 below. The fourth row in Table 14 is the combination assumed by the terminal before RRC configuration, and configuration after RRC is not possible.

[0197] [Table 14]

[0198]

[0199] NR supports a hierarchical signaling method, as illustrated in FIG. 8, for dynamic allocation of PDCCH beams. FIG. 8 is a diagram illustrating an example of a TCI state allocation method for a PDCCH in a wireless communication system according to an embodiment of the present disclosure.

[0200] Referring to FIG. 8, the base station can set N TCI states (805, 810, …, 820) to the terminal through RRC signaling (800), and can set some of them as TCI states for CORESET (825). Thereafter, the base station can indicate one of the TCI states (830, 835, 840) for CORESET to the terminal through MAC CE signaling (845). Thereafter, the terminal receives the PDCCH based on the beam information included in the TCI state indicated by the MAC CE signaling.

[0201] FIG. 9 is a diagram illustrating a TCI indication MAC CE signaling structure for the PDCCH DMRS. Referring to FIG. 9, the TCI indication MAC CE signaling for the PDCCH DMRS consists of 2 bytes (16 bits) (octet 1 (900) + octet 2 (905)) and includes a 5-bit serving cell ID (915), a 4-bit CORESET ID (920), and a 7-bit TCI state ID (925).

[0202] FIG. 10 is a diagram illustrating an example of beam configuration of a control resource set (CORESET) and a search space according to the above description. Referring to FIG. 10, a base station can indicate one of the TCI state lists included in the CORESET (1000) configuration through MAC CE signaling (1005). Thereafter, until another TCI state is indicated to the corresponding CORESET through another MAC CE signaling, the terminal considers that the same QCL information (beam #1, 1005) is applied to all one or more search spaces (1010, 1015, 1020) connected to the CORESET. The above-described PDCCH beam allocation method has a problem in that it is difficult to indicate a beam change faster than the MAC CE signaling delay, and also has a disadvantage in that the same beam is applied to all CORESETs regardless of the search space characteristics, which makes flexible PDCCH beam operation difficult. The embodiments of the present disclosure below provide a more flexible PDCCH beam configuration and operation method. In describing the embodiments of the present disclosure below, several distinct examples are provided for convenience of explanation, but these are not mutually exclusive and can be applied in appropriate combination depending on the situation.

[0203] A base station can set one or more TCI states for a specific control region to a terminal, and can activate one of the set TCI states through a MAC CE activation command. For example, if {TCI state#0, TCI state#1, TCI state#2} are set as TCI states in control region #1, the base station can transmit a command to the terminal to activate TCI state#0 for control region #1 through MAC CE. Based on the activation command for the TCI state received through MAC CE, the terminal can correctly receive DMRS of the corresponding control region based on QCL information in the activated TCI state.

[0204] For a control region (control region #0) with an index set to 0, if the terminal has not received a MAC CE activation command for the TCI state of control region #0, the terminal can assume that it has QCL with the SS / PBCH block identified during the initial access process or the non-contention-based random access process that is not triggered by a PDCCH command for the DMRS transmitted in control region #0.

[0205] For a control region (control region #X) whose index is set to a value other than 0, if the terminal has not set a TCI state for the control region #X, or has set one or more TCI states but has not received a MAC CE activation command to activate one of them, the terminal may assume that the DMRS transmitted in the control region #X is QCL with the SS / PBCH block identified during the initial access process.

[0206] [PDSCH: Frequency Resource Allocation Related]

[0207] FIG. 11 is a diagram illustrating an example of frequency-axis resource allocation of a physical downlink shared channel (PDSCH) in a wireless communication system according to one embodiment of the present disclosure.

[0208] FIG. 11 is a diagram illustrating three frequency axis resource allocation methods, type 0 (11-00), type 1 (11-05), and dynamic switch (11-10), which can be set via an upper layer in an NR wireless communication system.

[0209] Referring to Fig. 11, if a terminal is configured to use only resource type 0 through upper layer signaling (11-00), some downlink control information (DCI) that allocates PDSCH to the terminal includes a bitmap consisting of NRBG bits. The conditions for this will be explained later. At this time, NRBG means the number of RBGs (resource block groups) determined as shown in [Table 15] 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.

[0210] [Table 15]

[0211]

[0212] If the terminal is configured to use only resource type 1 through upper layer signaling (11-05), some DCIs that allocate PDSCH to the terminal It contains frequency axis resource allocation information consisting of bits. The conditions for this will be explained later. Through this, the base station can set the starting VRB (11-20) and the length of frequency axis resources (11-25) allocated continuously therefrom.

[0213] If a terminal is configured to use both resource type 0 and resource type 1 through upper layer signaling (11-10), some DCIs that allocate PDSCH to the terminal include frequency-axis resource allocation information consisting of bits of the larger value (11-35) among the payload (11-15) for configuring resource type 0 and the payload (11-20, 11-25) for configuring resource type 1. The conditions for this will be explained later. At this time, one bit may be added to the first part (MSB) of the frequency-axis resource allocation information in the DCI, and if the bit has a value of '0', it may indicate that resource type 0 is used, and if the bit has a value of '1', it may indicate that resource type 1 is used.

[0214] [PDSCH / PUSCH: Time Resource Allocation Related]

[0215] Below, a time domain resource allocation method for data channels in next-generation mobile communication systems (5G or NR systems) is described.

[0216] 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, a mapping type of the PDSCH or PUSCH, etc. For example, information such as [Table 16] or [Table 17] below may be transmitted from the base station to the terminal.

[0217] [Table 16]

[0218]

[0219] [Table 17]

[0220]

[0221] The base station can notify the terminal of one of the entries in the table for the time domain resource allocation information described above via L1 (layer-1) signaling (e.g., DCI) (e.g., it can be indicated by the 'time domain resource allocation' field in the DCI). The terminal can obtain the time domain resource allocation information for the PDSCH or PUSCH based on the DCI received from the base station.

[0222] FIG. 12 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.

[0223] Referring to FIG. 12, 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 (12-00) and length (12-05) of an OFDM symbol within a slot dynamically indicated through DCI.

[0224] FIG. 13 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.

[0225] Referring to FIG. 13, when the subcarrier spacing of the data channel and the control channel are the same (13-00, 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 (13-05, 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.

[0226] [PUSCH: Transmission method related]

[0227] 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 in DCI format 0_0 or 0_1.

[0228] Configured grant Type 1 PUSCH transmission can be semi-statically configured by receiving configuredGrantConfig including rrc-ConfiguredUplinkGrant of [Table 18] through higher-order 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 18] through higher-order signaling. When PUSCH transmission operates by configured grant, parameters applied to PUSCH transmission are applied through configuredGrantConfig of higher-order signaling of [Table 18], except for dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, and scaling of UCI-OnPUSCH provided by pusch-Config of [Table 19]. If the terminal has been provided with transformPrecoder in configuredGrantConfig, which is the upper signaling of [Table 18], the terminal applies tp-pi2BPSK in pusch-Config of [Table 19] to PUSCH transmission operated by the configured grant.

[0229] [Table 18]

[0230]

[0231]

[0232] 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 19], is 'codebook' or 'nonCodebook'.

[0233] 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 23], the UE does not expect to be scheduled with DCI format 0_1.

[0234] [Table 19]

[0235]

[0236]

[0237] 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).

[0238] 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.

[0239] 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'.

[0240] 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.

[0241] 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.

[0242] 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.

[0243] 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.

[0244] 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.

[0245] 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.

[0246] 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 set through the srs-ResourceIndicator, which is a higher-order 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.

[0247] 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.

[0248] [Regarding terminal capability reporting]

[0249] In LTE and NR, a terminal, while connected to a serving base station, can perform a procedure to report its supported capabilities to the base station. In the description below, this is referred to as a UE capability report.

[0250] A base station can transmit a UE capability inquiry message requesting a capability report to a connected terminal. The message can include a UE capability request for each RAT (radio access technology) type of the base station. The RAT type-specific request can include information on a combination of supported frequency bands, etc. In addition, in the case of the UE capability inquiry message, UE capabilities for multiple RAT types can be requested through a single RRC message container transmitted by the base station, or the base station can include multiple UE capability inquiry messages including UE capability requests for each RAT type and transmit them to the terminal. That is, the UE capability inquiry can be repeated multiple times in one message, and the terminal can compose a corresponding UE capability information message and report it multiple times. In the next-generation mobile communication system, a UE capability request can be made for MR-DC (Multi-RAT dual connectivity), including NR, LTE, and EN-DC (E-UTRA - NR dual connectivity). Additionally, the terminal capability inquiry message is typically transmitted initially after the terminal is connected to the base station, but the base station may request it under any conditions when necessary.

[0251] In the above step, the terminal that receives the UE capability report request from the base station configures the terminal capability based on the RAT type and band information requested from the base station. Below is a summary of how the terminal configures the UE capability in the NR system.

[0252] 1. If the UE receives a list of LTE and / or NR bands through a UE capability request from the base station, the UE configures a band combination (BC) for EN-DC and NR stand-alone (SA). That is, it configures a candidate list of BCs for EN-DC and NR SA based on the bands requested to the base station via FreqBandList. Furthermore, the bands are prioritized in the order listed in FreqBandList.

[0253] 2. If the base station requests UE capability reporting by setting the "eutra-nr-only" flag or the "eutra" flag, the UE completely removes NR SA BCs from the configured BC candidate list. This operation can only occur when the LTE base station (eNB) requests the "eutra" capability.

[0254] 3. The terminal then removes fallback BCs from the BC candidate list constructed in the above step. Here, a fallback BC is a BC obtained by removing at least one band corresponding to an SCell from a random BC. This step can be omitted because the BC before removing the band corresponding to at least one SCell can already cover the fallback BC. This step also applies to MR-DC, i.e., to LTE bands. The BCs remaining after this step are the final "candidate BC list."

[0255] 4. The terminal selects BCs to report by selecting BCs that match the requested RAT type from the final "candidate BC list" above. In this step, the terminal constructs the supportedBandCombinationList in a set order. That is, the terminal constructs BCs and UE capabilities to report in the order of the preset rat-Type (nr -> eutra-nr -> eutra). In addition, it constructs a featureSetCombination for the constructed supportedBandCombinationList, and constructs a list of "candidate feature set combinations" from the candidate BC list after removing the list for the fallback BC (which contains capabilities of the same or lower level). The "candidate feature set combinations" above include feature set combinations for both NR and EUTRA-NR BCs, and can be obtained from the feature set combinations in the UE-NR-Capabilities and UE-MRDC-Capabilities containers.

[0256] 5. Also, if the requested rat Type is eutra-nr and has an effect, featureSetCombinations are included in both containers: UE-MRDC-Capabilities and UE-NR-Capabilities. However, the NR feature set is included only in UE-NR-Capabilities.

[0257] After terminal capabilities are configured, the terminal transmits a terminal capability information message containing the terminal capabilities to the base station. Based on the terminal capabilities received from the terminal, the base station then performs appropriate scheduling and transmission / reception management for the terminal.

[0258] [CA / DC related]

[0259] FIG. 14 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.

[0260] Referring to FIG. 14, 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.

[0261] Key features of NR SDAP (S25, S70) may include some of the following:

[0262] - Transfer of user plane data

[0263] - Mapping function between QoS flow and data bearer for both DL and UL

[0264] - Marking function of QoS flow ID for both uplink and downlink (marking QoS flow ID in both DL and UL packets)

[0265] - Ability to map reflective QoS flow to data bearer for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

[0266] 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.

[0267] The main functions of NR PDCP (S30, S65) may include some of the following functions:

[0268] - Header compression and decompression (ROHC only)

[0269] - User data transfer function

[0270] - In-sequence delivery of upper layer PDUs

[0271] - Out-of-sequence delivery of upper layer PDUs

[0272] - PDCP PDU reordering for reception

[0273] - Duplicate detection of lower layer SDUs

[0274] - Retransmission function (Retransmission of PDCP SDUs)

[0275] - Encryption and decryption functions (Ciphering and deciphering)

[0276] - Timer-based SDU discard in uplink.

[0277] 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.

[0278] The main functions of NR RLC (S35, S60) may include some of the following functions:

[0279] - Data transfer function (Transfer of upper layer PDUs)

[0280] - In-sequence delivery of upper layer PDUs

[0281] - Out-of-sequence delivery of upper layer PDUs

[0282] - ARQ function (Error Correction through ARQ)

[0283] - Concatenation, segmentation and reassembly of RLC SDUs

[0284] - Re-segmentation of RLC data PDUs

[0285] - Reordering of RLC data PDUs

[0286] - Duplicate detection function

[0287] - Protocol error detection

[0288] - RLC SDU discard function

[0289] - RLC re-establishment function

[0290] 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.

[0291] The out-of-sequence delivery function of the NR RLC device mentioned 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 one RLC SDU is received divided into multiple RLC SDUs, and may include a function of storing and arranging the RLC SN or PDCP SN of received RLC PDUs to record lost RLC PDUs.

[0292] 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.

[0293] - Mapping function (Mapping between logical channels and transport channels)

[0294] - Multiplexing / demultiplexing of MAC SDUs

[0295] - Scheduling information reporting function

[0296] - HARQ function (Error correction through HARQ)

[0297] - Priority handling between logical channels of one UE

[0298] - Priority handling between UEs by means of dynamic scheduling

[0299] - MBMS service identification function

[0300] - Transport format selection function

[0301] - Padding function

[0302] 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.

[0303] 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 CA (carrier aggregation) that uses multiple carriers in a single TRP, 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) that uses 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.

[0304] Referring to the above-described PDCCH and beam configuration-related descriptions, the current Rel-15 and Rel-16 NR do not support PDCCH repetitive transmission, making it difficult to achieve the required reliability in scenarios requiring high reliability, such as URLLC. The present disclosure provides a method for repetitively transmitting PDCCHs through multiple transmission points (TRPs) to improve PDCCH reception reliability at a terminal. Specific methods are described in detail in the following examples.

[0305] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. The contents of the present disclosure can be applied to FDD (frequency division duplex), TDD (time division duplex) and / or XDD (cross division duplex) (and / or SBFD (subband non-overlapping full duplex), full duplex) systems. In the present disclosure below, upper signaling (or upper layer signaling) refers to a signal transmission method in which a base station transmits a signal to a terminal using a downlink data channel of a physical layer, or a terminal transmits a signal to a base station using an uplink data channel of a physical layer, and may also be referred to as RRC signaling, PDCP signaling, or MAC (medium access control) control element (MAC control element; MAC CE).

[0306] In the present disclosure, when determining whether cooperative communication is applied, the terminal may use various methods, such as having the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied have a specific format, or including a specific indicator that indicates whether cooperative communication is applied, or scrambled with a specific RNTI by the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied, or assuming cooperative communication is applied in a specific section indicated by a higher layer. For the convenience of the following description, the case where the terminal receives the PDSCH to which cooperative communication is applied based on conditions similar to the above will be referred to as the NC-JT case.

[0307] 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.

[0308] - MIB (Master Information Block)

[0309] - SIB (System Information Block) or SIB

[0310] - RRC (Radio Resource Control)

[0311] - MAC (Medium Access Control) CE (Control Element)

[0312] In addition, L1 signaling may be signaling corresponding to at least one or a combination of one or more signaling methods using the physical layer channel or signaling below.

[0313] - PDCCH (Physical Downlink Control Channel)

[0314] - DCI (Downlink Control Information)

[0315] - UE-specific DCI

[0316] - Group common DCI

[0317] - Common DCI

[0318] - Scheduling DCI (e.g. DCI used for scheduling downlink or uplink data)

[0319] - Non-scheduled DCI (e.g. DCI not intended for scheduling downlink or uplink data)

[0320] - PUCCH (Physical Uplink Control Channel)

[0321] - UCI (Uplink Control Information)

[0322] 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.

[0323] 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.

[0324] [DMRS related]

[0325] Next, the antenna port field indications included in DCI format 1_1 and DCI format 1_2 defined in the above-described [Table 7] are described. The antenna port fields in DCI formats 1_1 and 1_2 can be expressed with 4, 5, or 6 bits and can be indicated through the following [Table 20-1] to [Table 20-8]. The indications of the antenna port field can be identified according to the following [Table 20-1] to [Table 20-8].

[0326] [Table 20-1] Antenna port(s) (1000 + DMRS port), dmrs-Type=1, maxLength=1

[0327]

[0328] [Table 20-2] Antenna port(s) (1000 + DMRS port), dmrs-Type=1, maxLength=1

[0329]

[0330] [Table 20-3] Antenna port(s) (1000 + DMRS port), dmrs-Type=1, maxLength=2

[0331]

[0332] [표 20-4] Antenna port(s) (1000 + DMRS port), dmrs-Type=1, maxLength=2

[0333]

[0334] [표 20-5]: Antenna port(s) (1000 + DMRS port), dmrs-Type=2, maxLength=1

[0335]

[0336] [표 20-6]: Antenna port(s) (1000 + DMRS port), dmrs-Type=2, maxLength=1

[0337]

[0338] [표 20-7]: Antenna port(s) (1000 + DMRS port), dmrs-Type=2, maxLength=2

[0339]

[0340]

[0341] [표 20-8]: Antenna port(s) (1000 + DMRS port), dmrs-Type=2, maxLength=2

[0342]

[0343]

[0344] [Table 20-1] and [Table 20-2] are the tables used when dmrs-type is 1 and maxLength is 1, [Table 20-3] and [Table 20-4] are the tables used when dmrs-Type=1 and maxLength=2, [Table 20-5] and [Table 20-6] are the tables used when dmrs-type=2 and maxLength=1, and [Table 20-7] and [Table 20-8] are the tables used when drms-tpye is 2 and maxLength is 2. The indication (bit) of the antenna port field may be determined according to [Table 20-1] or [Table 20-2] when dmrs-type is indicated as 1 and maxLength is indicated as 1, determined according to [Table 20-3] or [Table 20-4] when dmrs-Type=1, maxLength=2, determined according to [Table 20-5] or [Table 20-6] when dmrs-type=2, maxLength=1, and determined according to [Table 20-7] or [Table 20-8] when drms-tpye is 2 and maxLength is 2. In the present disclosure, being indicated using a specific table may mean that the indication (bit) is determined according to a specific table or a relationship defined by the specific table.

[0345] If the terminal receives a MAC-CE that activates a code point indicating two TCI states for at least one code point of the TCI state field in the DCI, the terminal may be instructed to a DMRS port using [Table 20-2], [Table 20-4], [Table 20-6], and [Table 20-8]; otherwise, the terminal may be instructed to a DMRS port using [Table 20-1], [Table 20-3], [Table 20-5], and [Table 20-7]. If the terminal is instructed with a code point indicating two TCI states through the TCI state field, the terminal may be instructed with an entry indicating DMRS port 1000, 1002, 1003 for NC-JT scheduling purposes in [Table 20-2], [Table 20-4], [Table 20-6], and [Table 20-8], and the entry may be entry 12 in [Table 20-2], entry 31 in [Table 20-4], entry 24 in [Table 20-6], or entry 58 in [Table 20-8].

[0346] For DCI format 1_1, if the terminal has both upper layer signaling dmrs-DownlinkForPDSCH-MappingTypeA and dmrs-DownlinkForPDSCH-MappingTypeB set, the bit length of the Antenna port field in DCI format 1_1 is max{x- A , x B} can be determined, where x A Wow x B may mean the bit length of the Antenna port field determined through dmrs-DownlinkForPDSCH-MappingTypeA and dmrs-DownlinkForPDSCH-MappingTypeB, respectively. If x A Wow x B If a PDSCH mapping type corresponding to a smaller value is scheduled, |x A -x B| The MSB (most significant bit) bits of the number can be assigned as 0 bits and transmitted.

[0347] For DCI format 1_2, if the terminal has not been configured with the upper layer signaling antennaPortsFieldPresenceDCI-1-2, the DCI format 1_2 may not have an Antenna port field. In other words, in this case, the length of the Antenna port field may be 0 bits, and the terminal may determine the DMRS port by assuming the 0th entry of [Table 20-1], [Table 20-3], [Table 20-5], and [Table 20-7]. If the terminal has been configured with the upper layer signaling antennaPortsFieldPresenceDCI-1-2, the bit length of the Antenna port field in the DCI format 1_2 may be determined similarly to the case of the DCI format 1_1 described above. If the terminal has received both upper layer signaling dmrs-DownlinkForPDSCH-MappingTypeA-DCI-1-2 and dmrs-DownlinkForPDSCH-MappingTypeB-DCI-1-2, the bit length of the Antenna port field in DCI format 1_2 is max{x- A , x B} can be determined, where x A Wow x B may mean the bit length of the Antenna port field determined through dmrs-DownlinkForPDSCH-MappingTypeA-DCI-1-2 and dmrs-DownlinkForPDSCH-MappingTypeB-DCI-1-2, respectively. If x A Wow x B If a PDSCH mapping type corresponding to a smaller value is scheduled, |x A -x B | The MSB bits corresponding to the number can be assigned as 0 bits and transmitted.

[0348] In [Table 20-1] to [Table 20-8], the numbers 1, 2, and 3 indicated by Number of DMRS CDM group(s) without data mean CDM (code division multiplexing) groups {0}, {0, 1}, and {0, 1, 2}, respectively. DMRS port(s) is the index of the ports used in order. The antenna port is indicated by DMRS port + 1000. The CDM group of DMRS is connected to the antenna port and the method of generating the DMRS sequence as shown in [Table 21-1] and [Table 21-2]. [Table 21-1] shows the parameters when dmrs-type=1 is used, and [Table 21-2] shows the parameters when dmrs-type=2 is used.

[0349] [Table 21-1]: Parameters for PDSCH DM-RS dmrs-type=1.

[0350]

[0351] [Table 21-2]: Parameters for PDSCH DM-RS dmrs-type=2.

[0352]

[0353] The DMRS sequence according to each parameter is determined by the following mathematical expression 3. In mathematical expression 3, p means DMRS port, k means subcarrier index, l means OFDM symbol index, μ means subcarrier spacing, wf(k') and wt(l') mean FD-OCC (frequency domain orthogonal cover code) and TD-OCC (time domain orthogonal cover code) coefficients according to k' and l' values, respectively. is the spacing between CDM groups expressed as the number of subcarriers. In [Mathematical Formula 3] is a scaling factor that represents the ratio between the EPRE (energy per RE) of PDSCH and the EPRE of DMRS. It can be calculated as follows, depending on the number of CDM groups: 1, 2, 3. The value can be 0 dB, -3 dB, -4.77 dB.

[0354] [Equation 3]

[0355]

[0356] The position of the DM-RS symbol is and section and are given by [Table 22-1] to [Table 22-2] below. In case of PDSCH mapping type A, is the interval between the first OFDM symbol of the slot and the last OFDM symbol of the scheduled PDSCH resource within the slot. For PDSCH mapping type B, is a period of scheduled PDSCH resources.

[0357] [Table 22-1]

[0358]

[0359] [Table 22-2]

[0360]

[0361] The time domain index l' and the supported antenna ports p are given in [Table 22-3]. If the upper layer parameter maxLength is not set in DMRS-DownlinkConfig, a single-symbol DM-RS is used, and if the upper layer parameter maxLength in DMRS-DownlinkConfig is equal to len2, a single-symbol or double-symbol DM-RS is determined by the associated DCI.

[0362] [Table 22-3]

[0363]

[0364] When DMRS type 1 is used, if a terminal is scheduled for a single codeword using [Table 20-1] and [Table 20-3] and is directed to entries 2, 9, 10, 11, 30, or is scheduled for a single codeword using [Table 20-2] and is directed to entries 2, 9, 10, 11, 12, or is scheduled for a single codeword using [Table 20-4] and is directed to entries 2, 9, 10, 11, 30, 31, or is scheduled for two codewords, the terminal can be regarded as single-user MIMO (SU-MIMO) scheduling. That is, the terminal can assume that no other terminals are scheduled on any remaining orthogonal DMRS ports other than the DMRS port assigned to the scheduled PDSCH, and may not expect multi-user MIMO (MU-MIMO) scheduling. In such a case, the terminal may not assume that other terminals are co-scheduled and may not perform multi-user MIMO reception operations such as cancellation, nulling, or whitening of multi-user interference.

[0365] When DMRS type 2 is used, if a terminal is scheduled for a single codeword using [Table 20-5] and [Table 20-7] and is indicated by entries 2, 10, and 23, or is scheduled for a single codeword using [Table 20-6] and is indicated by entries 2, 10, 23, and 24, or is scheduled for a single codeword using [Table 20-8] and is indicated by entries 2, 10, 23, and 58, or is scheduled for two codewords, the terminal may regard it as single-user MIMO scheduling. That is, the terminal may assume that no other terminals are scheduled on any remaining orthogonal DMRS ports other than the DMRS port assigned to the scheduled PDSCH, and may not expect multi-user MIMO scheduling. In such cases, the terminal may not perform multi-user MIMO reception operations such as canceling, nulling, or whitening multi-user interference without assuming that other terminals are co-scheduled.

[0366] The terminal may not expect more than one additional DMRS symbol to be set via the upper layer signaling dmrs-AdditionalPosition while the maximum number of front-loaded DMRS symbols is set to len2 via the upper layer signaling maxLength.

[0367] A terminal may not expect the actual number of front-loaded DMRS symbols, the actual number of additional DMRS symbols, the DMRS symbol positions, and the DMRS type settings to be different for all terminals scheduled for multi-user MIMO.

[0368] For a terminal with a PRG (precoding resource block group) size of 2 or 4, frequency resource allocations for other terminals co-scheduled using other orthogonal DMRS ports within the same CDM group as the DMRS port to which the terminal is directed may not be expected to be misaligned in the PRG unit grid.

[0369] For PDSCH scheduled with DCI format 1_1 and 1_2, the terminal may assume that the CDM groups indicated by the column “Number of DMRS CDM group(s) without data” in [Table 20-1] to [Table 20-8] may include DMRS ports allocated to other terminals that may be co-scheduled via a multi-user MIMO scheme and may not be used for data transmission purposes of the terminal, and the meaning of the values ​​indicated by the column “Number of DMRS CDM group(s) without data” in [Table 20-1] to [Table 20-8] being 1, 2, and 3 can be understood as meaning that the indices of the CDM groups corresponding to the meanings described above correspond to CDM groups 0, {0,1}, and {0,1,2}, respectively.

[0370] If a terminal has been configured with the upper layer signaling dmrs-FD-OCC-disableForRank1PDSCH and has been allocated one DMRS port for PDSCH scheduling, the terminal may not expect that a DMRS port with a different FD-OCC among other orthogonal DMRS ports belonging to the same CDM group as the allocated one DMRS port will be allocated to another terminal.

[0371] Next, the antenna port field indications included in DCI format 0_1 ​​and DCI format 0_2 defined in the above-described [Table 5] are described. The antenna port fields in DCI formats 0_1 and 0_2 can be expressed with 3, 4, or 5 bits and can be indicated through the following [Table 20-9] to [Table 20-24]. The indications of the antenna port field can be identified according to the following [Table 20-9] to [Table 20-24].

[0372] [Table 20-9] Antenna port(s), transform precoder is disabled, dmrs-Type=1, maxLength=1, rank = 1

[0373]

[0374] [Table 20-10] Antenna port(s), transform precoder is disabled, dmrs-Type=1, maxLength=1, rank = 2

[0375]

[0376] [Table 20-11] Antenna port(s), transform precoder is disabled, dmrs-Type=1, maxLength=1, rank = 3

[0377]

[0378] [Table 20-12] Antenna port(s), transform precoder is disabled, dmrs-Type=1, maxLength=1, rank = 4

[0379]

[0380] [표 20-13] Antenna port(s), transform precoder is disabled, dmrs-Type=1, maxLength=2, rank = 1

[0381]

[0382] [표 20-14] Antenna port(s), transform precoder is disabled, dmrs-Type=1, maxLength=2, rank = 2

[0383]

[0384] [표 20-15] Antenna port(s), transform precoder is disabled, dmrs-Type=1, maxLength=2, rank = 3

[0385]

[0386] [표 20-16] Antenna port(s), transform precoder is disabled, dmrs-Type=1, maxLength=2, rank = 4

[0387]

[0388] [표 20-17] Antenna port(s), transform precoder is disabled, dmrs-Type=2, maxLength=1, rank=1

[0389]

[0390] [표 20-18] Antenna port(s), transform precoder is disabled, dmrs-Type=2, maxLength=1, rank=2

[0391]

[0392] [표 20-19] Antenna port(s), transform precoder is disabled, dmrs-Type=2, maxLength=1, rank =3

[0393]

[0394] [표 20-20] Antenna port(s), transform precoder is disabled, dmrs-Type=2, maxLength=1, rank =4

[0395]

[0396] [표 20-21] Antenna port(s), transform precoder is disabled, dmrs-Type=2, maxLength=2, rank=1

[0397]

[0398] [표 20-22] Antenna port(s), transform precoder is disabled, dmrs-Type=2, maxLength=2, rank=2

[0399]

[0400] [표 20-23] Antenna port(s), transform precoder is disabled, dmrs-Type=2, maxLength=2, rank=3

[0401]

[0402] [표 20-24] Antenna port(s), transform precoder is disabled, dmrs-Type=2, maxLength=2, rank=4

[0403]

[0404] [Table 20-9] to [Table 20-12] are tables used when dmrs-type is 1 and maxLength is 1, [Table 20-13] to [Table 20-16] are tables used when dmrs-Type=1 and maxLength=2, [Table 20-17] to [Table 20-20] are tables used when dmrs-type=2 and maxLength=1, and [Table 20-21] to [Table 20-24] are tables used when drms-type is 2 and maxLength is 2. The indication (bit) of the antenna port field may be determined according to at least one of [Table 20-9] to [Table 20-12] when dmrs-type is indicated as 1 and maxLength is indicated as 1, and may be determined according to at least one of [Table 20-13] to [Table 20-16] when dmrs-Type=1, maxLength=2, and may be determined according to at least one of [Table 20-17] to [Table 20-20] when dmrs-type=2, maxLength=1, and may be determined according to at least one of [Table 20-21] to [Table 20-24] when drms-tpye is 2 and maxLength is 2.

[0405] For DCI format 0_1, if the terminal has configured both dmrs-UplinkForPUSCH-MappingTypeA and dmrs-UplinkForPUSCH-MappingTypeB as upper layer signaling, the bit length of the Antenna port field in DCI format 0_1 ​​can be determined as max{xA, xB}, where xA and xB can represent the bit lengths of the Antenna port field determined through dmrs-UplinkForPUSCH-MappingTypeA and dmrs-UplinkForPUSCH-MappingTypeB, respectively. If a PUSCH mapping type corresponding to a smaller value between xA and xB is scheduled, the MSB bits corresponding to |xA-xB| can be allocated as 0 bits and transmitted.

[0406] For DCI format 0_2, if the terminal has not been configured with the upper layer signaling antennaPortsFieldPresenceDCI-0-2, the DCI format 0_2 may not have an Antenna port field. That is, in this case, the length of the Antenna port field may be 0 bits, and the terminal may determine the DMRS port by assuming the 0th entry of [Table 20-9] to [Table 20-24]. If the terminal has been configured with the upper layer signaling antennaPortsFieldPresenceDCI-0-2, the bit length of the Antenna port field in DCI format 0_2 may be determined similarly to the case of the DCI format 0_1 ​​described above. If the terminal has been configured with both the upper layer signaling dmrs-UplinkForPUSCH-MappingTypeA-DCI-0-2 and dmrs-UplinkForPUSCH-MappingTypeB-DCI-0-2, the bit length of the Antenna port field in DCI format 0_2 can be determined as max{xA, xB}, where xA and xB can represent the bit lengths of the Antenna port field determined through dmrs-UplinkForPUSCH-MappingTypeA-DCI-0-2 and dmrs-UplinkForPUSCH-MappingTypeB-DCI-0-2, respectively. If a PDSCH mapping type corresponding to a smaller value between xA and xB is scheduled, the MSB bits corresponding to the number of |xA-xB| can be allocated as 0 bits and transmitted.

[0407] In [Table 20-9] to [Table 20-24], the numbers 1, 2, and 3 indicated by Number of DMRS CDM group(s) without data mean CDM group {0}, {0, 1}, and {0, 1, 2}, respectively. DMRS port(s) is the index of the port used in order. The antenna port is indicated by DMRS port + 1000. The CDM group of DMRS is connected to the antenna port and the method of generating the DMRS sequence as shown in [Table 21-1a] and [Table 21-2a]. [Table 21-1a] shows the parameters when dmrs-type=1 is used, and [Table 21-2a] shows the parameters when dmrs-type=2 is used.

[0408] [Table 21-1a]: Parameters for PUSCH DM-RS dmrs-type=1.

[0409]

[0410] [Table 21-2a]: Parameters for PUSCH DM-RS dmrs-type=2.

[0411]

[0412] The DMRS sequence for each parameter is determined by the following mathematical expression 3-1. Mathematical expression 3-1 exemplifies the case where transmission precoding is not activated. In mathematical expression 3-1, represents the DMRS port, k represents the subcarrier index, l represents the OFDM symbol index, μ represents the subcarrier spacing, wf(k') and wt(l') represent the FD-OCC (frequency domain orthogonal cover code) and TD-OCC (time domain orthogonal cover code) coefficients according to the k' and l' values, respectively. is the spacing between CDM groups expressed as the number of subcarriers. In [Mathematical Formula 3-1] is a scaling factor that represents the ratio between the EPRE (energy per RE) of PUSCH and the EPRE of DMRS. It can be calculated as follows, depending on whether the number of CDM groups is 1, 2, or 3. The values ​​can be 0 dB, -3 dB, and -4.77 dB, respectively.

[0413] [Equation 3-1]

[0414]

[0415] In Equation 3-1, υ is the number of transmission layers. According to Equation 3-1, the intermediate quantity can be precoded by the precoding matrix W, multiplied by a scaling factor, and mapped to a physical resource. and means antenna port, resource element It is satisfied that it is included within the common resource block allocated for PUSCH transmission.

[0416] The position of the DM-RS symbol is and section and are given by [Table 23-1] to [Table 23-3] below. Specifically, in case of PUSCH mapping type A, when intra-slot frequency hopping is not used, is the interval between the first OFDM symbol of a slot and the last OFDM symbol of the scheduled PUSCH resource within the slot, as shown in Table 23-1 to Table 23-2. In case of PDSCH mapping type B, when intra-slot frequency hopping is not used, is a period of scheduled PDSCH resources, following Table 23-1 to Table 23-2. When intra-slot frequency hopping is used, is the duration per hop, as shown in Table 23-3.

[0417] [Table 23-1]

[0418]

[0419] [Table 23-2]

[0420]

[0421] [Table 23-3]

[0422]

[0423] The time domain index l' and the supported antenna ports p are given in [Table 23-4].

[0424] [Table 23-4]

[0425]

[0426] If frequency hopping is not used, the UE may have to assume that the upper layer signaling dmrs-AdditionalPosition is set to 'pos2', and up to two additional DMRS symbols may be used for PUSCH transmission. If frequency hopping is used, the UE may have to assume that the upper layer signaling dmrs-AdditionalPosition is set to 'pos1', and up to one additional DMRS symbol may be used for PUSCH transmission.

[0427] For PUSCH scheduled with DCI format 0_1 ​​and 0_2, the UE may assume that the CDM groups indicated by the column “Number of DMRS CDM group(s) without data” in [Table 20-9] to [Table 20-24] may include DMRS ports allocated to other UEs that may be co-scheduled via a multi-user MIMO scheme and may not be used for data transmission purposes of the UE, and the meaning of the values ​​indicated by the column “Number of DMRS CDM group(s) without data” in [Table 20-9] to [Table 20-24] being 1, 2, and 3 can be understood as meaning that the indexes of the CDM groups corresponding to the meanings described above correspond to CDM groups 0, {0,1}, and {0,1,2}, respectively.

[0428] <First embodiment: Enhanced DMRS type 1 and 2 support method supporting increased number of orthogonal ports>

[0429] As one embodiment of the present disclosure, a method for supporting enhanced DMRS types 1 and 2 that support an increased number of orthogonal ports is described. This embodiment can operate in combination with other embodiments.

[0430] The advanced 5G specifications can support enhanced DMRS type 1 and DMRS type 2 that support an increased number of orthogonal ports while maintaining the same RE (resource element) usage and overhead compared to DMRS type 1 and DMRS type 2 supported in the initial 5G specifications for both uplink and downlink.

[0431] In the case of the existing DMRS type 1, up to 4 and 8 orthogonal DMRS ports can be supported when the number of front-loaded symbols is 1 and 2, respectively, and in the case of DMRS type 2, up to 6 and 12 orthogonal DMRS ports can be supported when the number of front-loaded symbols is 1 and 2, respectively. Starting from these support items, in the case of the enhanced DMRS type 1, up to 8 and 16 orthogonal DMRS ports can be supported when the number of front-loaded symbols is 1 and 2, respectively, and in the case of the enhanced DMRS type 2, up to 12 and 24 orthogonal DMRS ports can be supported when the number of front-loaded symbols is 1 and 2, respectively. In the description of the present disclosure, the new DMRS types supporting the increased number of orthogonal ports may be named as one of “enhanced DMRS types 1 and 2”, “new DMRS types 1 and 2”, “new DMRS types 1 and 2”, “DMRS types 1-1 and 2-1”, or “DMRS types 3 and 4”, and similar extended names that may be called to mean that they have improved functions from the existing DMRS types 1 and 2 may not be excluded. Although the following description focuses on the downlink, the present disclosure can be similarly applied to uplink DMRS support.

[0432] If the terminal supports enhanced DMRS type 1 and 2, the terminal can report the terminal capability of supporting enhanced DMRS type 1 and 2 to the base station. At this time, the terminal capability report can be transmitted to the base station on a per-band basis, and can also be transmitted on a more detailed basis on a per-FS (feature set) or per-FSPC (feature set per component carrier) basis. In addition, the terminal capability report can be supported differently by FR (frequency range) and can be a terminal capability report limited to FR1 only. The terminal capability report can be reported by FR (frequency range) and / or for FR1. In addition, the terminal capability report may include information that, for the enhanced DMRS type 1, the number of front-loaded symbols is 1 and 2, the terminal can support up to 8 and 16 orthogonal DMRS ports, respectively, and for the enhanced DMRS type 2, the number of front-loaded symbols is 1 and 2, the terminal can support up to 12 and 24 orthogonal DMRS ports, respectively. The terminal may report through a common terminal capability for enhanced DMRS type 1 and 2, or may report whether it supports only enhanced DMRS type 1, and / or only enhanced DMRS type 2, and / or supports both enhanced DMRS type 1 and 2, and / or may report support for enhanced DMRS type 1 and 2 separately through individual terminal capabilities.

[0433] Additionally, if the terminal supports dynamic switching between the enhanced DMRS type and the legacy DMRS type, the terminal can report the capability through the terminal capability. Here, the dynamic switching between the legacy type and the enhanced type can mean that the DMRS type configured through upper layer signaling can be changed through MAC-CE, or that the DMRS type can be selected between the legacy type and the enhanced type through DCI, or both. If the support for enhanced DMRS type 1 and 2 is reported through a common terminal capability, the terminal can report the support for dynamic switching for DMRS type 1 and 2 as a single terminal capability, while reporting whether it supports dynamic switching only for DMRS type 1 and enhanced DMRS type 1, and / or only for dynamic switching for DMRS type 2 and enhanced DMRS type 2, and / or whether both types support dynamic switching between the legacy type and the enhanced type. Alternatively, a terminal may report support for enhanced DMRS types 1 and 2 through a common terminal capability, or may report support for enhanced DMRS types 1 and 2 through individual terminal capabilities, and may report support for dynamic switching between legacy and enhanced types through individual terminal capabilities for each type.

[0434] In addition, when the terminal operates in enhanced DMRS type 1 or 2, if the terminal supports both the legacy DMRS type 1 or 2 and multi-user MIMO scheduling, the terminal can report the corresponding capability through the terminal capability. Here, the multi-user MIMO scheduling can be co-schedule between the legacy DMRS type 1 and the enhanced DMRS type 1, and / or co-schedule between the legacy DMRS type 2 and the enhanced DMRS type 2. Similarly to the above, the terminal can report the terminal capability for co-scheduling between the legacy type and the enhanced type as a common terminal capability, so that only co-scheduling between the legacy type 1 and the enhanced type 1 is possible, and / or only co-scheduling between the legacy type 2 and the enhanced type 2 is possible, and / or both types 1 and 2 can support co-scheduling between the legacy type and the enhanced type, and / or can report it through individual terminal capabilities for each type.

[0435] For a terminal that has reported the terminal capability, the base station can configure the enhanced DMRS type 1 and 2 schemes to the terminal through upper layer signaling using the following methods.

[0436] - [Upper setting method 1] For example, the terminal can be configured to support the enhanced DMRS type in DMRS-DownlinkConfig, which is an upper layer signaling.

[0437] ■ [Upper-layer setting method 1-1] dmrs-Type-r18, a higher layer signaling similar to dmrs-Type, which is a higher layer signaling that determines the existing type, can be set, and dmrs-Type-r18 can be used to define an enhanced DMRS type other than DMRS type 1 or 2. dmrs-Type, which is a higher layer signaling that determines the existing type, is a field for selecting the DMRS type used for DL, and indicates that DMRS type 2 is used. If this field is not present, the terminal uses DMRS type 1. In addition to dmrs-Type, a new RRC IE called dmrs-Type-r18 can be set in DMRS-DownlinkConfig, which is an upper layer signaling, for the terminal. Through this dmrs-Type-r18, one of DMRS type 1, 2, or enhanced DMRS type 1, 2 can be determined, or one of enhanced DMRS type 1 or 2 can be determined. For example, as shown in [Table 24-1] below, if dmrs-Type-r18 is set, one of DMRS type 2, enhanced DMRS type 1 or 2 can be determined, the existing dmrs-Type can be ignored, and if dmrs-Type-r18 is not set, the DMRS type can be determined according to the setting method of dmrs-Type. As another example, if dmrs-Type-r18 is set, either enhanced DMRS type 1 or 2 can be determined, and the existing dmrs-Type can be ignored; if dmrs-Type-r18 is not set, the DMRS type can be determined according to how dmrs-Type is set.When such an upper configuration method is used, the terminal can use only one of the conventional DMRS type (e.g., DMRS type 1 or 2) and the enhanced DMRS type (e.g., enhanced DMRS type 1 or 2) for each PDSCH mapping type A or B. Such an upper configuration method may not allow dynamic switching between the conventional and enhanced methods, or may be an upper configuration method that does not consider dynamic switching itself. In this case, the RRC IE name dmrs-Type-r18 is only an example, and the actual RRC IE name may be different from this. That is, the name of the RRC IE is an example, and the present disclosure is not limited thereto.

[0438] [Table 24-1]

[0439]

[0440]

[0441] ■ [Upper setting method 1-2] The existing dmrs-Type can maintain its existing meaning of determining either DMRS type 1 or 2, while a new RRC IE that has the meaning of whether enhanced DMRS type 1 or 2 can be additionally set. For example, as shown in [Table 24-2] below, if the terminal is not configured for dmrs-Type, which is an upper layer signaling, from the base station and is not configured for enhanced-Dmrs-Type-r18, the terminal can support (use) the existing method for DMRS type 1. In addition, if the terminal is not configured for dmrs-Type and is configured for enhanced-Dmrs-Type-r18 as enabled, it can mean that the terminal can support (use) the enhanced method for DMRS type 1. If the terminal is configured for dmrs-Type (ENUMERATED {type2}) and enhanced-Dmrs-Type-r18 is set to enabled, it may mean that the terminal can support (use) the enhanced method for DMRS type 2. At this time, if the terminal supports dynamic switching between the legacy type and the enhanced type, if the terminal is configured for enhanced-Dmrs-Type-r18, the terminal can perform dynamic switching without additional upper layer signaling, or can be configured by the base station whether to perform dynamic switching through additional upper layer signaling, dynamicSwitchType. For the definition of RRC IEs other than enhanced-Dmrs-Type-r18 in [Table 24-2], refer to Table 24-1 above.

[0442] [Table 24-2]

[0443]

[0444] - [Upper configuration method 2] To support the enhanced DMRS type, the terminal can separately configure the support of the enhanced DMRS type in PDSCH-Config through a new RRC IE without using the upper layer signaling DMRS-DownlinkConfig. The RRC IE to support the enhanced DMRS type can be included in PDSCH-Config. For example, as shown in [Table 24-3] below, if the terminal has not been configured with the upper layer signaling enhanced-Dmrs-Type-r18 from the base station, the terminal can determine the DMRS type according to the existing DMRS-DownlinkConfig configuration. If the terminal has been configured with the upper layer signaling enhanced-Dmrs-Type-r18 from the base station, the terminal can use the enhanced method for the DMRS type determined by the existing DMRS-DownlinkConfig configuration. At this time, if the terminal supports dynamic switching between the existing type and the enhanced type, if the terminal is configured with enhanced-Dmrs-Type-r18, the terminal can perform dynamic switching without additional upper layer signaling, or can receive dynamic switching settings from the base station through additional upper layer signaling, dynamicSwitchType.

[0445] [Table 24-3]

[0446]

[0447] [Enhanced DMRS type 1 support method]

[0448] As another embodiment of a method for supporting the enhanced DMRS type 1 described above, when using the enhanced DMRS type 1, time and frequency resource mapping of DMRS RE and FD-OCC and TD-OCC coefficients at that time can be determined based on the following [Mathematical Formula 4-1] and [Table 26-1-4]. The following items are written based on the demodulation signal (PDSCH DMRS) of the downlink data channel, and can be similarly applied to the demodulation signal (PUSCH DMRS) of the uplink data channel, and in this case, the DMRS port number can be 0 to 15, not 1000 to 1015 as shown in the first column of [Table 21-1-1]. In the following [Mathematical Formula 4-1], v can mean the number of layers of the PDSCH or PUSCH. Unless specifically stated otherwise, the parameters of Equation 4-1 may refer to the descriptions of Equations 3 to 3-1 described above.

[0449] [Equation 4-1]

[0450]

[0451] [Table 21-1-1] Parameters for [Enhanced DMRS type 1 support method]

[0452]

[0453] The [Enhanced DMRS type 1 support method] based on the above [Mathematical Formula 4-1] and [Table 21-1-1] uses a total of two CDM groups, and in the case of one front-loaded DMRS symbol, each CDM group can include four DMRS ports, so that up to eight orthogonal DMRS ports can be supported, and in the case of two front-loaded DMRS symbols, each CDM group can include eight DMRS ports, so that a total of 16 orthogonal DMRS ports can be supported. Since the number of DMRS ports within a CDM group is increased while maintaining the number of CDM groups of the existing DMRS type 1, which is two, and the OCC length for this is increased to 4, the scheduling of the PDSCH to be transmitted together with the DMRS can be used in units of two RBs, and the DMRS can be mapped to the same RE position as the existing DMRS type 1.

[0454] However, the existing DMRS type 1 assumes that the channels of two REs (e.g., RE#0 and RE#2) located 2 REs apart are the same, and applies OCC to the two REs to distinguish orthogonal ports. In the case of one front-loaded DMRS symbol, a total of 6 REs are used within 1 RB per port, so 3 OCCs of length 2 are used. On the other hand, based on the [Enhanced DMRS type 1 support method], a total of 12 REs are used within 2 RBs per port for one front-loaded DMRS symbol, and 4 orthogonal antenna ports can be distinguished by using OCCs of length 4 applied to 4 adjacent REs. In this case, an OCC of length 4 is applied to 4 REs, and each of the 4 REs can be located 2 REs apart from each other. That is, since OCC must be applied by considering 4 REs whose relative RE positions are 0, 2, 4, and 6 as the same channel, the channel estimation performance may be lower than that of the existing DMRS type 1. Therefore, in the case of this improved DMRS type 1, it can be used for multi-user MIMO purposes in a channel with less frequency selective characteristics. According to the above [Table 21-1-1], ports 1000 to 1015 are used to ensure orthogonality between all ports among the OCCs with a length of 4. The values ​​can be determined, and the values ​​in the above table are exemplary, and the present disclosure does not exclude other values. In the above [Mathematical Formula 4-1] is a scaling factor that represents the ratio between the EPRE (energy per RE) of PDSCH and the EPRE of DMRS. It can be calculated as follows, depending on whether the number of CDM groups is 1 or 2. The values ​​can be 0 dB and -3 dB, respectively.

[0455] [Enhanced DMRS type 2 support method]

[0456] Based on the following [Mathematical Formula 4-2] and [Table 21-1-2], when using the enhanced DMRS type 2, the time and frequency resource mapping of the DMRS RE and the FD-OCC and TD-OCC coefficients at that time can be determined. The following is written based on the demodulation signal (PDSCH DMRS) of the downlink data channel, and can be similarly applied to the demodulation signal (PUSCH DMRS) of the uplink data channel, and in this case, the DMRS port number can be 0 to 23, not 1000 to 1023 as shown in the first column of [Table 21-1-2]. In the following [Mathematical Formula 4-2], v can mean the number of layers of the PDSCH or PUSCH. Unless specifically stated otherwise, the parameters of Mathematical Formula 4-2 can refer to the descriptions of Mathematical Formulas 3 to 3-1 described above.

[0457] [Equation 4-2]

[0458]

[0459] [Table 21-1-2]: Parameters for [Enhanced DMRS type 2 support method]

[0460]

[0461] [Enhanced DMRS type 2 support method] based on the above [Mathematical Formula 4-2] and [Table 21-1-2] uses a total of 3 CDM groups, and in the case of 1 front-loaded DMRS symbol, each CDM group can include 4 DMRS ports, so a total of 12 orthogonal DMRS ports can be supported, and in the case of 2 front-loaded DMRS symbols, each CDM group can include 8 DMRS ports, so a total of 24 orthogonal DMRS ports can be supported. Since the number of DMRS ports within a CDM group is increased while maintaining the number of CDM groups, the scheduling of the PDSCH to be transmitted together with the DMRS can be maintained in units of 1 RB as before, and the DMRS can be mapped to the same RE position as the existing DMRS type 2.

[0462] However, the existing DMRS type 2 assumed that the channels of two consecutive REs were the same, and applied OCC to the two REs to distinguish orthogonal ports. In the case of one front-loaded DMRS symbol, a total of 4 REs were used within one RB per port, so two OCCs of length 2 were used. On the other hand, based on the [Enhanced DMRS type 2 support method], a total of 4 REs were used within one RB per port for one front-loaded DMRS symbol, and a single OCC of length 4 can be used to distinguish a total of four orthogonal ports. In this case, an OCC of length 4 is applied to two consecutive RE sets that are 6 REs apart from each other, that is, four REs whose relative RE positions are 0, 1, 6, and 7, respectively, should be regarded as the same channel and OCC should be applied. Therefore, the channel estimation performance may be lower than that of the existing DMRS type 2. Therefore, for this improved DMRS type 2, it can be used for multi-user MIMO purposes in channels with less frequency selective characteristics. In [Mathematical Formula 4-2] is a scaling factor that represents the ratio between the EPRE (energy per RE) of PDSCH and the EPRE of DMRS. It can be calculated as follows, depending on whether the number of CDM groups is 1, 2, or 3. The value can be 0 dB, -3 dB, -4.77 dB.

[0463] For the above-described [enhanced DMRS type 1 support method] and [enhanced DMRS type 2 support method], the terminal can report terminal capabilities to the base station, meaning that each support method is possible. The terminal capabilities may be valid only for FR1, or valid for both FR1 and FR2. The terminal capabilities may include information indicating that the maximum number of supported ports is 8 when using one front-loaded DMRS symbol or 16 when using two front-loaded DMRS symbols for enhanced DMRS type 1, and 12 when using one front-loaded DMRS symbol or 24 when using two front-loaded DMRS symbols for enhanced DMRS type 2. After the base station receives the terminal capabilities, it can configure corresponding upper layer signaling, which can be one of the above-described upper layer signaling configuration methods or independent upper layer signaling.

[0464] The base station and the terminal can support at least one of the above [enhanced DMRS type 1 support method] or [enhanced DMRS type 2 support method] by using a configuration method through upper layer signaling, by using an instruction method based on L1 signaling, by using a combination of upper layer signaling and L1 signaling, or by using a method fixedly specified in the standard.

[0465] <Second Embodiment: Enhanced DMRS Type 1 and 2 Additional Support Method Supporting an Increased Number of Orthogonal Ports>

[0466] As one embodiment of the present disclosure, an additional support method for enhanced DMRS types 1 and 2 supporting an increased number of orthogonal ports is described. This embodiment can operate in combination with other embodiments.

[0467] As an additional parameter for the above-described [Enhanced DMRS type 1 support method], the relationship regarding which CDM group it is included in, which FD-OCC index, and which TD-OCC index can be used depending on which DMRS port is used can be additionally defined through [Table 21-2-1] below. In addition, as an additional parameter for the above-described [Enhanced DMRS type 2 support method], the relationship regarding which CDM group it is included in, and which FD-OCC index and which TD-OCC index can be used depending on which DMRS port is used can be additionally defined through [Table 21-2-2] below. The following [Table 21-2-3] and [Table 21-2-4] can define the FD-OCC indexes available in [Table 21-2-1] and [Table 21-2-2], and the following [Table 21-2-5] and [Table 21-2-6] can define the TD-OCC indexes available in [Table 21-2-1] and [Table 21-2-2]. In the following [Table 21-2-1] and [Table 21-2-2], p indicates a DMRS port, and for PDSCH, p can be used, and for PUSCH, a value obtained by subtracting 1000 from p can be used.

[0468] In [Table 21-2-1] below, DMRS ports 1000 to 1003 and 1008 to 1011 can be used for single or double front-loaded DMRS symbols, and DMRS ports 1004 to 1007 and 1012 to 1015 can be used for double front-loaded DMRS symbols.

[0469] In [Table 21-2-2] below, DMRS ports 1000 to 1005 and 1012 to 1017 can be used for single or double front-loaded DMRS symbols, and DMRS ports 1006 to 1011 and 1018 to 1023 can be used for double front-loaded DMRS symbols.

[0470] In [Table 21-2-3] to [Table 21-2-6] below, j is an imaginary number and is sqrt(-1)(j 2 =-1) can mean.

[0471] In order to support the above-described [Enhanced DMRS type 1 support method] and [Enhanced DMRS type 2 support method], the following [Table 21-2-1] and [Table 21-2-2] may be used, respectively, and the indexes of FD-OCC and TD-OCC to be used in each of [Table 21-2-1] and [Table 21-2-2] may be determined using at least one of the following [Table 21-2-3] to [Table 21-2-6], and the determination may be set to the terminal by upper layer signaling from the base station, dynamically indicated by L1 signaling, notified by a combination of upper layer signaling and L1 signaling, or defined in the standard.

[0472] For scheduling of PDSCH and / or PUSCH from a base station, a terminal may determine one of the FD-OCC and TD-OCC from [Table 21-2-3] to [Table 21-2-6] below and apply them commonly to PDSCH and PUSCH scheduling.

[0473] For scheduling of PDSCH and / or PUSCH from a base station, a terminal may determine one FD-OCC and TD-OCC from among [Table 21-2-3] to [Table 21-2-6] and apply them to PDSCH scheduling, and determine another FD-OCC and TD-OCC from among [Table 21-2-3] to [Table 21-2-6] and apply them to PUSCH scheduling. For example, when scheduling PDSCH of a base station, a terminal may use the FD-OCC index and value of [Table 21-2-3] for the above-described enhanced DMRS types 1 and 2, and when scheduling PUSCH of a base station, a terminal may use the FD-OCC index and value of [Table 21-2-4] for the above-described enhanced DMRS types 1 and 2. This is merely an example, and the present disclosure is not limited thereto. For example, the same FD-OCC may be used for PDSCH and PUSCH, different TD-OCCs may be used for PDSCH and PUSCH, and the present disclosure may not exclude any other combinations.

[0474] [Table 21-2-1] and [Table 21-2-2] below are based on PDSCH DMRS, and can be similarly applied to PUSCH DMRS. In this case, the DMRS port number can be 0 to 15, not 1000 to 1015 as shown in the first column of [Table 21-2-1], and can be 0 to 23, not 1000 to 1023 as shown in the first column of [Table 21-2-2].

[0475] [Table 21-2-6] below is based on PUSCH DMRS, and can be similarly applied to PDSCH DMRS. In this case, the DMRS port number may be 100~1007, 1008~1015 instead of 0~7, 8~15 as shown in the first row of [Table 21-2-6] for enhanced DMRS type 1, and may be 1000~1011, 1012~1023 instead of 0~11, 12~23 as shown in the first row of [Table 21-2-6] for enhanced DMRS type 2.

[0476] [Table 21-2-1] Additional parameters for [Enhanced DMRS type 1 support method]

[0477]

[0478] [Table 21-2-2] Additional parameters for [Enhanced DMRS type 2 support method]

[0479]

[0480] [Table 21-2-3] Available FD-OCC indices and coefficients

[0481]

[0482] [Table 21-2-4] Other available FD-OCC indices and coefficients

[0483]

[0484] [Table 21-2-5] FD-OCC index and coefficient for [Enhanced DMRS type 1 support method] and [Enhanced DMRS type 2 support method]

[0485]

[0486] [Table 21-2-6] Another FD-OCC index and coefficient for [Enhanced DMRS type 1 support method] and [Enhanced DMRS type 2 support method]

[0487]

[0488] <Example 3: DMRS transmission and reception method of a terminal when DMRS type is not set>

[0489] In one embodiment of the present disclosure, a DMRS transmission and / or reception operation of a terminal is described when the terminal does not receive a DMRS type setting through upper layer signaling. This embodiment may operate in combination with other embodiments.

[0490] When a terminal receives DCI format 0_1 ​​and schedules PUSCH transmission, the terminal may receive upper layer signaling from the base station for DMRS to be transmitted together with the PUSCH. To this end, the terminal may receive dmrs-UplinkForPUSCH-MappingTypeA and / or dmrs-UplinkForPUSCH-MappingTypeB from the base station through upper layer signaling, and each of these may be applied to PUSCH mapping type A and / or PUSCH mapping type B.

[0491] For each entry of the Time Domain Resource Assignment (TDRA) field included in DCI format 0_1, the UE can receive information such as the mapping type, slot offset, and time resource allocation of the PUSCH scheduled through the corresponding DCI format 0_1 ​​through upper layer signaling. That is, the UE can expect that the same or different PUSCH mapping types are indicated for each entry of the TDRA field included in DCI format 0_1. For example, depending on the upper layer signaling configuration for each entry of the TDRA field, the UE can be indicated with PUSCH mapping type A for the first entry of the TDRA field through DCI format 0_1, and can be indicated with PUSCH mapping type B for the second entry of the TDRA field.

[0492] When a terminal receives DCI format 0_2 and schedules PUSCH transmission, the terminal may receive upper layer signaling for DMRS to be transmitted together with the PUSCH from the base station. To this end, the terminal may receive dmrs-UplinkForPUSCH-MappingTypeA-DCI-0-2-r16 and / or dmrs-UplinkForPUSCH-MappingTypeB-DCI-0-2-r16 from the base station through upper layer signaling, each of which may be applied to PUSCH mapping type A and / or PUSCH mapping type B.

[0493] For each entry of the Time Domain Resource Assignment (TDRA) field included in DCI format 0_2, the UE can receive the mapping type, slot offset, time resource allocation information, etc. of the PUSCH scheduled through the corresponding DCI format 0_2 through upper layer signaling. That is, the UE can expect that the same or different PUSCH mapping types are indicated for each entry of the TDRA field included in DCI format 0_2. For example, depending on the upper layer signaling setting for each entry of the TDRA field, the UE can be indicated PUSCH mapping type A for the first entry of the TDRA field through DCI format 0_2, and can be indicated PUSCH mapping type B for the second entry of the TDRA field.

[0494] The terminal can receive from the base station the presence or absence of the antenna port field in DCI format 0_2 through the upper layer signaling configuration. If the terminal receives the upper layer signaling antennaPortsFieldPresenceDCI-0-2, the terminal can expect the presence of the antenna port field in DCI format 0_2. If the terminal does not receive the upper layer signaling antennaPortsFieldPresenceDCI-0-2, the terminal can expect the absence of the antenna port field in DCI format 0_2. If the terminal does not receive the upper layer signaling dmrs-UplinkForPUSCH-MappingTypeA-DCI-0-2-r16 and dmrs-UplinkForPUSCH-MappingTypeB-DCI-0-2-r16, the terminal may not expect that antennaPortsFieldPresenceDCI-0-2 is set.

[0495] If antennaPortsFieldPresenceDCI-0-2 is not set and thus there is no antenna port field in DCI format 0_2, the terminal can expect to be indicated a DMRS port using the first entry in the table referenced by the antenna port field. For example, the terminal can interpret the value indicated by the antenna port field using one of the tables from [Table 20-9] to [Table 20-24] according to the upper layer signaling settings (e.g., whether dmrs-Type, maxLength, transform precoder is set, etc.). However, if antennaPortsFieldPresenceDCI-0-2 is not set for the terminal as described above and thus there is no antenna port field in DCI format 0_2, the terminal can obtain information on which DMRS port will be used using the first entry in [Table 20-9] to [Table 20-24]. In such cases, the terminal can be similarly applied to not only DMRS type 1 or 2, but also enhanced DMRS type 1 and enhanced DMRS type 2.

[0496] When a UE transmits a PUSCH, if the PUSCH transmission is not scheduled with DCI format 0_1 ​​or 0_2 in which the CRC is scrambled with C-RNTI, CS-RNTI, SP-CSI-RNTI (Semi-Persistent CSI RNTI), or MCS-C-RNTI (Modulation and Coding Scheme C-RNTI), is not a PUSCH transmission based on a configured grant, and is not a PUSCH transmission in a 2-step random access method (type-2 random access), the UE may use DMRS type 1 with one front-loaded DMRS symbol and transmit using DMRS port 0, and may not expect PUSCH data to be transmitted in the DMRS symbol, except when the time resource allocation length of the PUSCH is less than or equal to 2. The above-described PUSCH transmission may be scheduled with DCI format 0_0. That is, when a UE transmits a PUSCH scheduled with DCI format 0_1 ​​or 0_2, if the UE has not yet received a dedicated RRC configuration or has not yet received a DMRS-related configuration, the UE's behavior is not defined, so ambiguity may arise regarding DMRS transmission during such PUSCH transmission. This situation can be similarly applied to DCI format 0_3.

[0497] When a terminal receives DCI format 1_1 and is scheduled to receive PDSCH reception, the terminal can receive upper layer signaling for DMRS to be received together with the PDSCH from the base station. To this end, the terminal can receive dmrs-DownlinkForPDSCH-MappingTypeA and / or dmrs-DownlinkForPDSCH-MappingTypeB through upper layer signaling from the base station, and each can be applied to PDSCH mapping type A and / or PDSCH mapping type B.

[0498] For each entry of the Time Domain Resource Assignment (TDRA) field included in DCI format 1_1, the UE can receive the mapping type, slot offset, time resource allocation information, etc. of the PDSCH scheduled through the corresponding DCI format 1_1 through upper layer signaling. That is, the UE can expect that the same or different PDSCH mapping types are indicated for each entry of the TDRA field included in DCI format 1_1. For example, depending on the upper layer signaling setting for each entry of the TDRA field, the UE can be indicated PDSCH mapping type A for the first entry of the TDRA field through DCI format 1_1, and can be indicated PDSCH mapping type B for the second entry of the TDRA field.

[0499] When a terminal receives DCI format 1_2 and schedules PDSCH reception, the terminal can receive upper layer signaling for DMRS to be received together with the corresponding PDSCH from the base station. To this end, the terminal can receive dmrs-DownlinkForPDSCH-MappingTypeA-DCI-1-2-r16 and / or dmrs-DownlinkForPDSCH-MappingTypeB-DCI-1-2-r16 through upper layer signaling from the base station, and each can be applied to PDSCH mapping type A and / or PDSCH mapping type B.

[0500] For each entry of the Time Domain Resource Assignment (TDRA) field included in DCI format 1_2, the UE can receive the mapping type, slot offset, time resource allocation information, etc. of the PDSCH scheduled through the corresponding DCI format 1_2 through upper layer signaling. That is, the UE can expect that the same or different PDSCH mapping types are indicated for each entry of the TDRA field included in DCI format 1_2. For example, depending on the upper layer signaling setting for each entry of the TDRA field, the UE can be indicated PDSCH mapping type A for the first entry of the TDRA field through DCI format 1_2, and can be indicated PDSCH mapping type B for the second entry of the TDRA field.

[0501] The terminal can receive from the base station the presence or absence of the antenna port field in DCI format 1_2 through the upper layer signaling configuration. If the terminal receives the upper layer signaling antennaPortsFieldPresenceDCI-1-2, the terminal can expect the presence of the antenna port field in DCI format 1_2. If the terminal does not receive the upper layer signaling antennaPortsFieldPresenceDCI-1-2, the terminal can expect the absence of the antenna port field in DCI format 1_2. If the terminal does not receive the upper layer signaling dmrs-DownlinkForPDSCH-MappingTypeA-DCI-1-2-r16 and dmrs-DownlinkForPDSCH-MappingTypeB-DCI-1-2-r16, the terminal may not expect that antennaPortsFieldPresenceDCI-1-2 is set.

[0502] If antennaPortsFieldPresenceDCI-1-2 is not set and thus there is no antenna port field in DCI format 1_2, the terminal can expect to be indicated a DMRS port using the first entry in the table referenced by the antenna port field. For example, the terminal can interpret the value indicated by the antenna port field using one of the tables from [Table 20-1] to [Table 20-8] according to the upper layer signaling settings (e.g., whether dmrs-Type, maxLength are set, etc.). However, if antennaPortsFieldPresenceDCI-1-2 is not set for the terminal as described above and thus there is no antenna port field in DCI format 1_2, the terminal can obtain information on which DMRS port will be used using the first entry in [Table 20-1] to [Table 20-8]. In such cases, the terminal can be similarly applied to not only DMRS type 1 or 2, but also enhanced DMRS type 1 and enhanced DMRS type 2.

[0503] When a UE receives a PDSCH scheduled with DCI format 1_0, 4_0, or 4_1, or receives PDSCH scheduling before receiving RRC configuration for upper layer signaling dmrs-AdditionalPosition, maxLength, dmrs-Type, the UE may not expect PDSCH data to be transmitted on a DMRS symbol, except when the PDSCH mapping type is B and the time resource allocation length is less than or equal to 2, and may transmit the PDSCH using DMRS type 1 with one front-loaded DMRS symbol and using DMRS port 1000. In addition, the UE may not expect other UEs to be scheduled on orthogonal DMRS ports other than the DMRS port scheduled for the UE.

[0504] As described above, if the UE receives PDSCH scheduling before receiving the RRC configuration for dmrs-AdditionalPosition, maxLength, and dmrs-Type, which are upper layer signaling scheduled through DCI format 1_1 or 1_2, it can transmit using DMRS type 1 with one front-loaded DMRS symbol on DMRS port 1000, and this situation can respond to the case where there are no DMRS configurations corresponding to PDSCH mapping type A and PDSCH mapping type B. That is, if the UE has received a DMRS configuration for PDSCH mapping type A but has not received a DMRS configuration for PDSCH mapping type B, if the UE receives PDSCH scheduling based on PDSCH mapping type B, ambiguity may occur when receiving the PDSCH because it is not defined which DMRS the UE will assume to receive for the corresponding PDSCH. This situation can be similarly applied to DCI format 1_3.

[0505] As described above, when DMRS-related upper layer signaling is not configured, and when the terminal is scheduled for PDSCH reception or PUSCH transmission, there are cases where the terminal's behavior is undefined. These cases can be summarized as follows.

[0506] - When the terminal is scheduled for PUSCH transmission through DCI format 0_1 ​​or 0_3, if the DMRS configuration (at least dmrs-AdditionalPosition, maxLength, dmrs-Type) is not set for the terminal.

[0507] ■ [PUSCH DMRS Setting Situation 1-1] When DMRS is not set for both PUSCH mapping type A and PUSCH mapping type B

[0508] ■ [PUSCH DMRS Setting Situation 1-2] When DMRS is not set for either PUSCH mapping type A or PUSCH mapping type B

[0509] ■ When the terminal is scheduled for PUSCH transmission through DCI format 0_2, if the DMRS setting (at least dmrs-AdditionalPosition, maxLength, dmrs-Type) is not set for the terminal.

[0510] ■ [PUSCH DMRS Setting Situation 2-1] When DMRS is not set for both PUSCH mapping type A and PUSCH mapping type B

[0511] ■ [PUSCH DMRS Setting Situation 2-2] When DMRS is not set for either PUSCH mapping type A or PUSCH mapping type B

[0512] - When the terminal is scheduled to receive PDSCH through DCI format 1_1 or 1_3, if the DMRS configuration (at least dmrs-AdditionalPosition, maxLength, dmrs-Type) is not set for the terminal.

[0513] ■ [PDSCH DMRS setting situation 1-2] When DMRS setting is not done for either PDSCH mapping type A or PDSCH mapping type B

[0514] - When the terminal is scheduled to receive PDSCH through DCI format 1_2, if the DMRS setting (at least dmrs-AdditionalPosition, maxLength, dmrs-Type) is not set for the terminal.

[0515] ■ [PDSCH DMRS Setting Situation 2-2] When DMRS setting is not done for either PDSCH mapping type A or PDSCH mapping type B

[0516] For the above-described matters, the terminal and base station may consider at least one combination of the following matters for the DMRS settings to be assumed when transmitting and receiving PDSCH or PUSCH.

[0517] [Method 3-1]

[0518] When the UE is scheduled for PUSCH transmission with DCI format 0_1 ​​or 0_3 in the above [PUSCH DMRS configuration situation 1-1] and [PUSCH DMRS configuration situation 1-2], the UE may transmit the PUSCH DMRS assuming DMRS type 1, 1 front-loaded DMRS symbol (maxLength=1), and DMRS port 0. In this case, the UE may expect the PUSCH transmission to be scheduled with a single rank, and the antenna port field in DCI format 0_1 ​​or 0_3 may be regarded as reserved or may be ignored without interpretation.

[0519] When the UE is scheduled for PUSCH transmission in DCI format 0_1 ​​or 0_3 in the above [PUSCH DMRS configuration situation 1-1] and [PUSCH DMRS configuration situation 1-2], the UE can interpret the antenna port field in DCI format 0_1 ​​or 0_3 assuming DMRS type 1 and one front-loaded DMRS symbol (maxLength=1), and transmit the PUSCH DMRS determined thereby. In this case, the UE can expect that the rank value is indicated in the antenna port field when transmitting the PUSCH. That is, the UE can transmit a PUSCH configured with one or more ranks.

[0520] When the terminal is scheduled for PUSCH transmission in DCI format 0_2 in the above [PUSCH DMRS configuration situation 2-1] and [PUSCH DMRS configuration situation 2-2], the terminal may be capable of performing operations according to a combination of at least one of the following items.

[0521] - If the antenna port field exists in DCI format 0_2 by configuring the upper layer signaling antennaPortsFieldPresenceDCI-0-2, the terminal can transmit PUSCH DMRS assuming DMRS type 1, 1 front-loaded DMRS symbol (maxLength=1), and DMRS port 0. In this case, the terminal can expect to be scheduled with a single rank when transmitting PUSCH. In this case, the antenna port field in DCI format 0_2 can be considered reserved or ignored without interpretation.

[0522] - If the antenna port field exists in DCI format 0_2 by configuring the upper layer signaling antennaPortsFieldPresenceDCI-0-2, the terminal can interpret the antenna port field in DCI format 0_2 assuming DMRS type 1 and 1 front-loaded DMRS symbol (maxLength=1), and transmit the PUSCH DMRS determined through this. In this case, the terminal can expect the rank value of the PUSCH transmission to be indicated through the TPMI field (Precoding information and number of layers field). That is, the terminal can transmit a PUSCH composed of one or more ranks.

[0523] - If the terminal does not receive the upper layer signaling antennaPortsFieldPresenceDCI-0-2 and thus the antenna port field does not exist in the DCI format 0_2, the terminal can obtain information about which DMRS port will be used by using the first entry in [Table 20-9] to [Table 20-24], assuming DMRS type 1 and 1 front-loaded DMRS symbol (maxLength=1). In this case, the terminal can expect the rank value of the PUSCH transmission to be indicated through the TPMI field. That is, the terminal can transmit a PUSCH composed of one or more ranks.

[0524] ■ The terminal can use the first entry in Table 7.3.1.1.2-6 to Table 7.3.1.1.2-23 in the standard document TS38.212. That is, the terminal is Table 7.3.1.1.2-6, Table 7.3.1.1.2-7, Table 7.3.1.1.2-8, Table 7.3.1.1.2-9, Table 7.3.1.1.2-10, Table 7.3.1.1.2-11, Table 7.3.1.1.2-12, Table 7.3.1.1.2-13, Table 7.3.1.1.2-14, Table 7.3.1.1.2-15, Table 7.3.1.1.2-16, Table 7.3.1.1.2-17, Table 7.3.1.1.2-18, Table 7.3.1.1.2-19, Table 7.3.1.1.2-20, Table You can use the first entry in 7.3.1.1.2-21, Table 7.3.1.1.2-22, or Table 7.3.1.1.2-23.

[0525] ■ Alternatively, the terminal may be configured as per Table 7.3.1.1.2-6, Table 7.3.1.1.2-6A, Table 7.3.1.1.2-7, Table 7.3.1.1.2-7A, Table 7.3.1.1.2-8, Table 7.3.1.1.2-9, Table 7.3.1.1.2-10, Table 7.3.1.1.2-11, Table 7.3.1.1.2-12, Table 7.3.1.1.2-13, Table 7.3.1.1.2-14, Table 7.3.1.1.2-15, Table 7.3.1.1.2-16, Table 7.3.1.1.2-17, Table 7.3.1.1.2-18, Table The first entry in Table 7.3.1.1.2-19, Table 7.3.1.1.2-20, Table 7.3.1.1.2-21, Table 7.3.1.1.2-22, or Table 7.3.1.1.2-23 can be used.

[0526] ■ Alternatively, the terminal may use the first entry in Table 7.3.1.1.2-6 to Table 7.3.1.1.2-23, Table 7.3.1.1.2-38 to Table 7.3.1.1.2-41, Table 7.3.1.1.2-46 to Table 7.3.1.1.2-49, Table 7.3.1.1.2-54 to Table 7.3.1.1.2-57, and Table 7.3.1.1.2-62 to Table 7.3.1.1.2-65 in the standard document TS38.212. That is, the terminal is Table 7.3.1.1.2-6, Table 7.3.1.1.2-7, Table 7.3.1.1.2-8, Table 7.3.1.1.2-9, Table 7.3.1.1.2-10, Table 7.3.1.1.2-11, Table 7.3.1.1.2-12, Table 7.3.1.1.2-13, Table 7.3.1.1.2-14, Table 7.3.1.1.2-15, Table 7.3.1.1.2-16, Table 7.3.1.1.2-17, Table 7.3.1.1.2-18, Table 7.3.1.1.2-19, Table 7.3.1.1.2-20, Table 7.3.1.1.2-21, Table 7.3.1.1.2-22, Table 7.3.1.1.2-23, Table 7.3.1.1.2-38, Table 7.3.1.1.2-39, Table 7.3.1.1.2-40, Table 7.3.1.1.2-41, Table 7.3.1.1.2-46, Table 7.3.1.1.2-47, Table 7.3.1.1.2-48, Table 7.3.1.1.2-49, Table 7.3.1.1.2-54, Table 7.3.1.1.2-55, Table 7.3.1.1.2-56, Table 7.3.1.1.2-57, Table 7.3.1.1.2-62, Table You can use the first entry in Table 7.3.1.1.2-63, Table 7.3.1.1.2-64, or Table 7.3.1.1.2-65.

[0527] ■ Alternatively, the terminal may be configured as per Table 7.3.1.1.2-6, Table 7.3.1.1.2-6A, Table 7.3.1.1.2-7, Table 7.3.1.1.2-7A, Table 7.3.1.1.2-8, Table 7.3.1.1.2-9, Table 7.3.1.1.2-10, Table 7.3.1.1.2-11, Table 7.3.1.1.2-12, Table 7.3.1.1.2-13, Table 7.3.1.1.2-14, Table 7.3.1.1.2-15, Table 7.3.1.1.2-16, Table 7.3.1.1.2-17, Table 7.3.1.1.2-18, Table 7.3.1.1.2-19, Table 7.3.1.1.2-20, Table 7.3.1.1.2-21, Table 7.3.1.1.2-22, Table 7.3.1.1.2-23, Table 7.3.1.1.2-38, Table 7.3.1.1.2-39, Table 7.3.1.1.2-40, Table 7.3.1.1.2-41, Table 7.3.1.1.2-46, Table 7.3.1.1.2-47, Table 7.3.1.1.2-48, Table 7.3.1.1.2-49, Table 7.3.1.1.2-54, Table 7.3.1.1.2-55, Table 7.3.1.1.2-56, Table The first entry in Table 7.3.1.1.2-57, Table 7.3.1.1.2-62, Table 7.3.1.1.2-63, Table 7.3.1.1.2-64, or Table 7.3.1.1.2-65 can be used.

[0528] ■ Alternatively, if the terminal has received a specific upper layer signaling from the base station (for example, if the terminal has received an upper layer signaling from the base station that means that the terminal can receive scheduling for two uplink codewords through DCI format 0_2), the terminal may use Table 7.3.1.1.2-6, Table 7.3.1.1.2-6A, Table 7.3.1.1.2-7, Table 7.3.1.1.2-7A, Table 7.3.1.1.2-8, Table 7.3.1.1.2-9, Table 7.3.1.1.2-10, Table 7.3.1.1.2-11, Table 7.3.1.1.2-12, Table 7.3.1.1.2-13, Table 7.3.1.1.2-14, Table 7.3.1.1.2-15, Table 7.3.1.1.2-16, Table 7.3.1.1.2-17, Table 7.3.1.1.2-18, Table 7.3.1.1.2-19, Table 7.3.1.1.2-20, Table 7.3.1.1.2-21, Table 7.3.1.1.2-22, Table 7.3.1.1.2-23, Table 7.3.1.1.2-24, Table 7.3.1.1.2-25, Table 7.3.1.1.2-26, Table 7.3.1.1.2-27, Table 7.3.1.1.2-28, Table 7.3.1.1.2-29, Table 7.3.1.1.2-29, Table 7.3.1.1.2-21, Table 7.3.1.1.2-21, Table 7.3.1.1.2-21, Table 7.3.1.1.2-15, Table 7.3.1.1.2-15A, Table 7.3.1.1.2-15B, Table 7.3.1.1.2-15C, Table 7.3.1.1.2-15D, Table 7.3.1.1.2-16, Table 7.3.1.1.2-17, Table 7.3.1.1.2-18, Table 7.3.1.1.2-19, Table 7.3.1.1.2-19A, Table 7.3.1.1.2-19B, Table 7.3.1.1.2-20, Table 7.3.1.1.2-21, Table 7.3.1.1.2-22, Table 7.3.1.1.2-23, Table 7.3.1.1.2-23A, Table 7.3.1.1.2-23B, Table 7.3.1.1.2-23C, Table 7.3.1.1.2-23D, Table 7.3.1.1.2-38, Table 7.3.1.1.2-39, Table 7.3.1.1.2-40, Table 7.3.1.1.2-41, Table 7.3.1.1.2-42, Table 7.3.1.1.2-43, Table 7.3.1.1.2-44, Table 7.3.1.1.2-45, Table 7.3.1.1.2-46, Table 7.3.1.1.2-47, Table 7.3.1.1.2-48, Table 7.3.1.1.2-49, Table 7.3.1.1.2-50, Table 7.3.1.1.2-51, Table 7.3.1.1.2-52, Table 7.3.1.1.2-53, Table 7.3.1.1.2-54, Table 7.3.1.1.2-55, Table 7.3.1.1.2-56, Table 7.3.1.1.2-57, Table 7.3.1.1.2-58, Table 7.3.1.1.2-59, Table 7.3.1.1.2-60, Table 7.3.1.1.2-61, Table 7.3.1.1.2-62, Table 7.3.1.1.2-63, Table You can use the first entry in Table 7.3.1.1.2-64, Table 7.3.1.1.2-65, Table 7.3.1.1.2-66, Table 7.3.1.1.2-67, Table 7.3.1.1.2-68.

[0529] - If the antenna port field does not exist in DCI format 0_2 because the terminal does not receive the upper layer signaling antennaPortsFieldPresenceDCI-0-2, the terminal can obtain information about which DMRS port will be used by using the first entry in [Table 20-9], [Table 20-13], [Table 20-17], or [Table 20-21], assuming DMRS type 1 and 1 front-loaded DMRS symbol (maxLength=1). In this case, the terminal can expect to be scheduled in a single rank when transmitting PUSCH.

[0530] ■ The terminal can use the first entry in Table 7.3.1.1.2-6, Table 7.3.1.1.2-7, Table 7.3.1.1.2-8, Table 7.3.1.1.2-12, Table 7.3.1.1.2-16, and Table 7.3.1.1.2-20 in the standard document TS38.212.

[0531] ■ Alternatively, the terminal may use the first entry in Table 7.3.1.1.2-6, Table 7.3.1.1.2-6A, Table 7.3.1.1.2-7, Table 7.3.1.1.2-7A, Table 7.3.1.1.2-8, Table 7.3.1.1.2-12, Table 7.3.1.1.2-16, Table 7.3.1.1.2-20 in the standard document TS38.212.

[0532] ■ Alternatively, the terminal may use the first entry in Table 7.3.1.1.2-6, Table 7.3.1.1.2-7, Table 7.3.1.1.2-8, Table 7.3.1.1.2-12, Table 7.3.1.1.2-16, Table 7.3.1.1.2-20, Table 7.3.1.1.2-38, Table 7.3.1.1.2-46, Table 7.3.1.1.2-54, Table 7.3.1.1.2-62 in the standard document TS38.212.

[0533] ■ Alternatively, the terminal may use the first entry in Table 7.3.1.1.2-6, Table 7.3.1.1.2-6A, Table 7.3.1.1.2-7, Table 7.3.1.1.2-7A, Table 7.3.1.1.2-8, Table 7.3.1.1.2-12, Table 7.3.1.1.2-16, Table 7.3.1.1.2-20, Table 7.3.1.1.2-38, Table 7.3.1.1.2-46, Table 7.3.1.1.2-54, Table 7.3.1.1.2-62 in the standard document TS38.212.

[0534] When the terminal is scheduled to receive PDSCH with DCI format 1_1 or 1_3 in the above [PDSCH DMRS configuration situation 1-2], the terminal may receive PDSCH DMRS assuming DMRS type 1, 1 front-loaded DMRS symbol (maxLength=1), and DMRS port 1000. In addition, the terminal may not expect that another terminal is assigned to an orthogonal DMRS port other than the assigned DMRS port. In this case, the terminal may consider the antenna port field in DCI format 1_1 or 1_3 as reserved or may ignore it without interpretation.

[0535] When the terminal is scheduled to receive PDSCH in DCI format 1_2 in the above [PDSCH DMRS setting situation 2-2], it may be able to perform an operation according to a combination of at least one of the following items.

[0536] - If the terminal receives the upper layer signaling antennaPortsFieldPresenceDCI-1-2 and the antenna port field exists in DCI format 1_2, the terminal can receive PDSCH DMRS assuming DMRS type 1, 1 front-loaded DMRS symbol (maxLength=1), and DMRS port 1000. In this case, the terminal can expect to be scheduled in a single rank when receiving PDSCH. In this case, the terminal can consider the antenna port field in DCI format 1_2 as reserved or ignore it without interpretation.

[0537] - If the terminal receives the upper layer signaling antennaPortsFieldPresenceDCI-1-2 and thus the antenna port field exists in DCI format 1_2, the terminal can interpret the antenna port field in DCI format 1_2 assuming DMRS type 1 and 1 front-loaded DMRS symbol (maxLength=1) and transmit the PDSCH DMRS determined through this. In this case, the terminal can expect the rank value of PDSCH reception to be indicated through the antenna port field. That is, the terminal can receive a PDSCH composed of one or more ranks.

[0538] - If the antenna port field exists in DCI format 1_2 by configuring the upper layer signaling antennaPortsFieldPresenceDCI-1-2, the terminal can obtain information about which DMRS port will be used by using the first entry in [Table 20-1] to [Table 20-8], assuming DMRS type 1 and one front-loaded DMRS symbol (maxLength=1). In this case, the terminal can expect to be scheduled in a single rank when receiving PDSCH.

[0539] ■ The terminal can use the first entry in Table 7.3.1.2.2-1, 7.3.1.2.2-2, 7.3.1.2.2-3, 7.3.1.2.2-4 in the standard document TS38.212.

[0540] ■ Alternatively, the terminal may use the first entry in Table 7.3.1.2.2-1, 7.3.1.2.2-2, 7.3.1.2.2-3, 7.3.1.2.2-4, Table 7.3.1.2.2-7, 7.3.1.2.2-8, 7.3.1.2.2-9, 7.3.1.2.2-10 in the standard document TS38.212.

[0541] As described above, when the terminal is in [PUSCH DMRS configuration situation 1-1], [PUSCH DMRS configuration situation 1-2], [PUSCH DMRS configuration situation 2-1], [PUSCH DMRS configuration situation 2-2], [PDSCH DMRS configuration situation 1-2], and / or [PDSCH DMRS configuration situation 2-2], allowing the terminal to use DMRS type 1 when transmitting PUSCH and / or receiving PDSCH can reduce the implementation burden of the terminal by allowing the terminal to prepare only the channel estimation method for the simplest DMRS. In particular, when the terminal is in [PUSCH DMRS configuration situation 1-2], [PUSCH DMRS configuration situation 2-2], [PDSCH DMRS configuration situation 1-2], and / or [PDSCH DMRS configuration situation 2-2], since the terminal expects scheduling for PUSCH transmission or PDSCH reception requiring high robustness and low delay time through DCI format 0_2 or 1_2, DMRS type 1 with a larger amount of DMRS resources within the same resource can have higher robustness in channel estimation performance in the same channel environment, so that sufficient benefit can be guaranteed even in a situation where there is no DMRS configuration during terminal and base station operation.

[0542] In the above [Method 3-1], the terminal may also consider a method of fixedly using not only DMRS type 1, but also DMRS type 2, enhanced DMRS type 1, or enhanced DMRS type 2. In particular, DMRS type 1 may be fixedly used for PDSCH DMRS received by the terminal in consideration of the higher robustness and low delay described above, and since the PUSCH DMRS transmitted by the terminal is received by the base station, relatively high robustness may be secured, and since decoding for FD-OCC can be performed with length 2 even in the enhanced DMRS type depending on the scheduling situation for multiple terminals, the terminal may also consider a method of applying enhanced DMRS type 1 for PUSCH and DMRS type 1 for PDSCH.

[0543] The table of TS 38.212 exemplified in the above method 3-1 is given in Table 25 below.

[0544] [Table 25]

[0545]

[0546]

[0547]

[0548]

[0549]

[0550]

[0551]

[0552]

[0553]

[0554]

[0555]

[0556]

[0557]

[0558]

[0559]

[0560]

[0561]

[0562]

[0563]

[0564]

[0565]

[0566]

[0567]

[0568]

[0569]

[0570]

[0571]

[0572]

[0573] [Method 3-2]

[0574] If the terminal is in the above [PUSCH DMRS configuration situation 1-1], the terminal may be capable of operating according to a combination of at least one of the following items.

[0575] - If the terminal has not configured all DMRS types corresponding to the PUSCH that can be scheduled with DCI format 0_2 (i.e., if the terminal is in [PUSCH DMRS configuration situation 2-1]), the terminal can perform DMRS transmission of the PUSCH scheduled with DCI format 0_1 ​​or 0_3 based on the above [Method 3-1].

[0576] - If the UE has received some DMRS types corresponding to the PUSCH that can be scheduled with DCI format 0_2 (i.e., if the UE is in [PUSCH DMRS configuration situation 2-2] and has received only DMRS configurations corresponding to either PUSCH mapping type A or PUSCH mapping type B), the UE may apply the same DMRS configurations to the same PUSCH mapping types of the PUSCH scheduled with DCI format 0_1 ​​or 0_3 for the PUSCH mapping types for which the DMRS configurations for the PUSCH that can be scheduled with DCI format 0_2 have been received, and may perform DMRS transmission of the PUSCH scheduled with DCI format 0_1 ​​or 0_3 based on the above [Method 3-1] for the PUSCH mapping types for which the DMRS configurations for the PUSCH that can be scheduled with DCI format 0_2 have not been received. For example, if the UE has received the upper layer signaling configuration for dmrs-UplinkForPUSCH-MappingTypeA-DCI-0-2-r16 and has not received the upper layer signaling configuration for dmrs-UplinkForPUSCH-MappingTypeB-DCI-0-2-r16, if the UE is scheduled for a PUSCH corresponding to PUSCH mapping type A through DCI format 0_1 ​​or 0_3, the UE can transmit a DMRS for PUSCH mapping type A scheduled through DCI format 0_1 ​​or 0_3 based on the information of the configured dmrs-UplinkForPUSCH-MappingTypeA-DCI-0-2-r16, and if the UE is scheduled for a PUSCH corresponding to PUSCH mapping type B through DCI format 0_1 ​​or 0_3, the UE can perform PUSCH DMRS transmission based on the above [Method 3-1].

[0577] - If the UE has received a DMRS type corresponding to a PUSCH that can be scheduled with DCI format 0_2 (i.e., the UE has received upper layer signaling configurations for both dmrs-UplinkForPUSCH-MappingTypeA-DCI-0-2-r16 and dmrs-UplinkForPUSCH-MappingTypeB-DCI-0-2-r16), the UE may perform PUSCH DMRS transmission using the DMRS configuration for each PUSCH mapping type corresponding to DCI format 0_2 depending on which PUSCH mapping type the PUSCH scheduled with DCI format 0_1 ​​or 0_3 is. For example, if a UE receives DMRS configuration for each PUSCH mapping type of a PUSCH scheduled with DCI format 0_2, and dmrs-UplinkForPUSCH-MappingTypeA-DCI-0-2-r16 is set to DMRS type 1 and dmrs-UplinkForPUSCH-MappingTypeB-DCI-0-2-r16 is set to DMRS type 2, if a PUSCH scheduled through DCI format 0_1 ​​or 0_3 follows PUSCH mapping type A, the UE can assume DMRS type 1 when transmitting the corresponding PUSCH DMRS. Similarly, if a PUSCH scheduled through DCI format 0_1 ​​or 0_3 follows PUSCH mapping type B, the UE can assume DMRS type 2 when transmitting the corresponding PUSCH DMRS.

[0578] If the terminal is in the above [PUSCH DMRS configuration situation 1-2], that is, if the terminal has not received the DMRS configuration for only one of the PUSCH mapping types A or B for the PUSCH scheduled with DCI format 0_1 ​​or 0_3 (for example, if the terminal has received the upper layer signaling configuration from the base station for dmrs-UplinkForPUSCH-MappingTypeA and has not received the upper layer signaling configuration from the base station for dmrs-UplinkForPUSCH-MappingTypeB), the terminal, for the PUSCH mapping type for which the DMRS configuration has not been received, if there is a DMRS configuration for the same PUSCH mapping type scheduled with DCI format 0_2 (for example, if the terminal has received the upper layer signaling configuration from the base station for at least dmrs-UplinkForPUSCH-MappingTypeB-DCI-0-2-r16), the terminal may set the DMRS configuration for the PUSCH scheduled with DCI format 0_1 ​​or 0_3 without the DMRS configuration. When based on the PUSCH mapping type, the DMRS configuration set for the same PUSCH mapping type of the PUSCH scheduled with DCI format 0_2 can be used.For example, if the terminal has received the upper layer signaling configuration for dmrs-UplinkForPUSCH-MappingTypeA, but has not received the upper layer signaling configuration for dmrs-UplinkForPUSCH-MappingTypeB from the base station, and if the terminal has received the upper layer signaling configuration for dmrs-UplinkForPUSCH-MappingTypeB-DCI-0-2-r16 from the base station, when the terminal schedules the PUSCH through DCI format 0_1 ​​or 0_3, if it is PUSCH mapping type B, the corresponding DMRS configuration may be borrowed from dmrs-UplinkForPUSCH-MappingTypeB-DCI-0-2-r16. The terminal can transmit DMRS for PUSCH scheduled through DCI format 0_1 ​​or 0_3 based on dmrs-UplinkForPUSCH-MappingTypeB-DCI-0-2-r16.

[0579] If the terminal is in the above [PUSCH DMRS configuration situation 2-1], the terminal may be capable of operating according to a combination of at least one of the following items.

[0580] - If the terminal has not configured all DMRS types corresponding to the PUSCH that can be scheduled with DCI format 0_1 ​​or 0_3 (i.e., the terminal is in [PUSCH DMRS configuration situation 1-1]), the terminal can perform DMRS transmission of the PUSCH scheduled with DCI format 0_2 based on the above [Method 3-1].

[0581] - If the UE has received some configurations of DMRS types corresponding to PUSCHs that can be scheduled with DCI format 0_1 ​​or 0_3 (i.e., if the UE is in [PUSCH DMRS configuration situation 1-2] and has received only DMRS configurations corresponding to either PUSCH mapping type A or PUSCH mapping type B), the UE may apply the same DMRS configurations to the same PUSCH mapping type of PUSCH scheduled with DCI format 0_2 for the PUSCH mapping type for which it has received DMRS configurations for PUSCHs that can be scheduled with DCI format 0_1 ​​or 0_3, and may perform DMRS transmission of PUSCHs scheduled with DCI format 0_2 based on the above [Method 3-1] for the PUSCH mapping type for which it has not received DMRS configurations for PUSCHs that can be scheduled with DCI format 0_1 ​​or 0_3. For example, if the UE has received the upper layer signaling configuration for dmrs-UplinkForPUSCH-MappingTypeA and has not received the upper layer signaling configuration for dmrs-UplinkForPUSCH-MappingTypeB, if the UE is scheduled for a PUSCH corresponding to PUSCH mapping type A through DCI format 0_2, the UE can transmit a DMRS for PUSCH mapping type A scheduled through DCI format 0_2 based on the information of the configured dmrs-UplinkForPUSCH-MappingTypeA, and if the UE is scheduled for a PUSCH corresponding to PUSCH mapping type B through DCI format 0_2, the UE can perform PUSCH DMRS transmission based on the above [Method 3-1].

[0582] - If the UE has received a DMRS type corresponding to a PUSCH that can be scheduled with DCI format 0_1 ​​or 0_3 (i.e., the UE has received upper layer signaling configuration for both dmrs-UplinkForPUSCH-MappingTypeA and dmrs-UplinkForPUSCH-MappingTypeB), the UE may perform PUSCH DMRS transmission using the DMRS configuration for each PUSCH mapping type corresponding to DCI format 0_1 ​​or 0_3 depending on which PUSCH mapping type the PUSCH scheduled with DCI format 0_2 is. For example, if a UE receives DMRS configuration for each PUSCH mapping type of a PUSCH scheduled with DCI format 0_1 ​​or 0_3, and dmrs-UplinkForPUSCH-MappingTypeA is set to DMRS type 1 and dmrs-UplinkForPUSCH-MappingTypeB is set to DMRS type 2, if the PUSCH scheduled through DCI format 0_2 follows PUSCH mapping type A, the UE can assume DMRS type 1 when transmitting the corresponding PUSCH DMRS. Similarly, if the PUSCH scheduled through DCI format 0_2 follows PUSCH mapping type B, the UE can assume DMRS type 2 when transmitting the corresponding PUSCH DMRS.

[0583] If the terminal is in the above [PUSCH DMRS configuration situation 2-2], that is, if the terminal has not received the DMRS configuration for either PUSCH mapping type A or B for the PUSCH scheduled with DCI format 0_2 (for example, if the terminal has received the upper layer signaling configuration from the base station for dmrs-UplinkForPUSCH-MappingTypeA-DCI-0-2-r16 and has not received the upper layer signaling configuration from the base station for dmrs-UplinkForPUSCH-MappingTypeB-DCI-0-2-r16), the terminal, for the PUSCH mapping type for which the DMRS configuration has not been received, if there is a DMRS configuration for the same PUSCH mapping type scheduled with DCI format 0_1 ​​or 0_3 (for example, if the terminal has received the upper layer signaling configuration from the base station for at least dmrs-UplinkForPUSCH-MappingTypeB), the terminal determines whether the PUSCH scheduled through DCI format 0_2 is When based on a PUSCH mapping type without DMRS configuration, the DMRS configuration configured for the same PUSCH mapping type of a PUSCH scheduled with DCI format 0_1 ​​or 0_3 can be used.For example, if the terminal has received the upper layer signaling configuration for dmrs-UplinkForPUSCH-MappingTypeA-DCI-0-2-r16, but has not received the upper layer signaling configuration for dmrs-UplinkForPUSCH-MappingTypeB-DCI-0-2-r16 from the base station, and if the terminal has received the upper layer signaling configuration for dmrs-UplinkForPUSCH-MappingTypeB from the base station, when the terminal schedules a PUSCH through DCI format 0_2, if the PUSCH mapping type is B, the corresponding DMRS configuration may be borrowed from dmrs-UplinkForPUSCH-MappingTypeB. The terminal may transmit the DMRS for the PUSCH scheduled through DCI format 0_2 based on dmrs-UplinkForPUSCH-MappingTypeB.

[0584] If the terminal is in the above [PDSCH DMRS configuration situation 1-2], that is, if the terminal has not received the DMRS configuration for only one of the PDSCH mapping types A or B for the PDSCH scheduled by DCI format 1_1 or 1_3 (for example, if the terminal has received the upper layer signaling configuration from the base station for dmrs-DownlinkForPDSCH-MappingTypeA and has not received the upper layer signaling configuration from the base station for dmrs-DownlinkForPDSCH-MappingTypeB), the terminal, for the PDSCH mapping type for which the DMRS configuration has not been received, if there is a DMRS configuration for the same PDSCH mapping type scheduled by DCI format 1_2 (for example, if the terminal has received the upper layer signaling configuration from the base station for at least dmrs-DownlinkForPDSCH-MappingTypeB-DCI-1-2-r16), the terminal determines whether the PDSCH scheduled by DCI format 1_1 or 1_3 has the DMRS configuration. When based on a non-existent PDSCH mapping type, the DMRS configuration set for the same PDSCH mapping type of the PDSCH scheduled with DCI format 1_2 can be used.For example, if the terminal has received the upper layer signaling configuration for dmrs-DownlinkForPDSCH-MappingTypeA, but has not received the upper layer signaling configuration for dmrs-DownlinkForPDSCH-MappingTypeB from the base station, and if the terminal has received the upper layer signaling configuration for dmrs-DownlinkForPDSCH-MappingTypeB-DCI-1-2-r16 from the base station, when the terminal schedules the PDSCH through DCI format 1_1 or 1_3, if the PDSCH mapping type is B, the corresponding DMRS configuration may be borrowed from dmrs-DownlinkForPDSCH-MappingTypeB-DCI-1-2-r16. The terminal can receive DMRS for PDSCH scheduled through DCI format 1_1 or 1_3 based on dmrs-DownlinkForPDSCH-MappingTypeB-DCI-1-2-r16.

[0585] If the terminal is in the above [PDSCH DMRS configuration situation 2-2], that is, if the terminal has not received the DMRS configuration for only one of the PDSCH mapping types A or B for the PDSCH scheduled with DCI format 1_2 (for example, the terminal has received the upper layer signaling configuration from the base station for dmrs-DownlinkForPDSCH-MappingTypeA-DCI-1-2-r16 and has not received the upper layer signaling configuration from the base station for dmrs-DownlinkForPDSCH-MappingTypeB-DCI-1-2-r16), the terminal, for the PDSCH mapping type for which the DMRS configuration has not been received, if there is a DMRS configuration for the same PDSCH mapping type scheduled with DCI format 1_1 or 1_3 (for example, the terminal has received the upper layer signaling configuration from the base station for at least dmrs-DownlinkForPDSCH-MappingTypeB), the terminal performs the DMRS configuration for the PDSCH mapping type scheduled with DCI format 1_2. If the PDSCH is based on a PDSCH mapping type without DMRS configuration, the DMRS configuration configured for the same PDSCH mapping type of the PDSCH scheduled with DCI format 1_1 or 1_3 can be used.For example, if the terminal has received the upper layer signaling configuration for dmrs-DownlinkForPDSCH-MappingTypeA-DCI-1-2-r16, but has not received the upper layer signaling configuration for dmrs-DownlinkForPDSCH-MappingTypeB-DCI-1-2-r16 from the base station, and if the terminal has received the upper layer signaling configuration for dmrs-DownlinkForPDSCH-MappingTypeB from the base station, when the terminal schedules the PDSCH through DCI format 1_2, if the PDSCH mapping type is B, the corresponding DMRS configuration may be borrowed from dmrs-DownlinkForPDSCH-MappingTypeB. The terminal may receive the DMRS for the PDSCH scheduled through DCI format 1_2 based on dmrs-DownlinkForPDSCH-MappingTypeB.

[0586] In the above [Method 3-2], if there is no DMRS configuration for a specific PUSCH mapping type or PDSCH mapping type for a PUSCH or PDSCH that can be scheduled through a specific DCI format, the UE can borrow a DMRS configuration for the same PUSCH mapping type or the same PDSCH mapping type that can be scheduled through another DCI format, thereby enabling the use of the same DMRS type for each DCI format. Accordingly, the burden on the UE's receiver implementation and preparation that may arise due to the possibility of using different DMRS types can be reduced.

[0587] In the above [Method 3-2], if an enhanced DMRS type is set in the DMRS configuration for a specific PUSCH mapping type or a specific PDSCH mapping type corresponding to a specific DCI format, the same enhanced DMRS type may be used in the same PUSCH mapping type or the same PDSCH mapping type of another DCI format that borrows this, or the enhanced DMRS type may be ignored and a conventional DMRS type that is the same type but is not the enhanced DMRS type may be used.

[0588] For example, if there is no DMRS configuration for PUSCH mapping type A of PUSCH scheduled through DCI format 0_2, and if the DMRS configuration for PUSCH mapping type A of PUSCH scheduled through DCI format 0_1 ​​and 0_3 is set to enhanced DMRS type 1, the UE can use enhanced DMRS type 1 when transmitting PUSCH DMRS scheduled in the PUSCH mapping type A manner through DCI format 0_2.

[0589] As another example, if there is no DMRS configuration for PDSCH mapping type A of a PDSCH scheduled through DCI format 1_2, and the DMRS configuration for PDSCH mapping type A of a PDSCH scheduled through DCI formats 1_1 and 1_3 is set to enhanced DMRS type 1, the UE can use DMRS type 1 when transmitting a PDSCH DMRS scheduled in the PDSCH mapping type A manner through DCI format 1_2.

[0590] [Method 3-3]

[0591] If the terminal is in one of the above [PUSCH DMRS configuration situations 1-2], [PUSCH DMRS configuration situations 2-2], [PDSCH DMRS configuration situations 1-2], and [PDSCH DMRS configuration situations 2-2], that is, there is no DMRS configuration for either PUSCH mapping type A or B, or there is no DMRS configuration for either PDSCH mapping type A or B, the terminal may not expect that the PUSCH mapping type or PDSCH mapping type without DMRS configuration is indicated by the TDRA field in the DCI. That is, the terminal may not expect scheduling based on the mapping type without DMRS configuration. That is, if the terminal receives scheduling for a specific mapping type from the base station, it may assume that a corresponding DMRS configuration is necessarily present.

[0592] Through this, the terminal can exclude additional implementations for performing basic operations for mapping types without DMRS settings, and can make maximum use of information indicated by DCI to exclude situations in which the antenna port field, even though it has at least 4 bits as in [Method 3-1], must be considered reserved or ignored without interpretation.

[0593] [Method 3-4]

[0594] When the UE is in [PUSCH DMRS configuration situation 1-1], [PUSCH DMRS configuration situation 1-2], [PUSCH DMRS configuration situation 2-1], or [PUSCH DMRS configuration situation 2-2], if the UE receives a PUSCH scheduled with DCI format 0_1, 0_2, or 0_3 and there is no DMRS configuration corresponding to the mapping type of the corresponding PUSCH, the UE may use the DMRS configuration applied to the configured grant-based PUSCH as the upper layer signaling to be applied to the corresponding PUSCH DMRS. In this case, the UE may be configured with respect to the DMRS configuration applied to the configured grant-based PUSCH through cg-DMRS-Configuration in configuredGrantConfig, which is the upper layer signaling. cg-DMRS-Configuration, which can be applied to the DMRS configuration of Configured grant-based PUSCH, can be applied to both Type 1, which is a semi-static transmission, and Type 2, which is activated through DCI, and thus can be similarly applied to dynamic grant-based PUSCH.

[0595] The terminal may be notified by the base station of at least one combination of [Method 3-1] to [Method 3-4] through at least one combination of upper layer signaling, MAC-CE signaling, and L1 signaling, or may expect that at least one combination of [Method 3-1] to [Method 3-4] is fixedly defined in the standard. Additionally, if the terminal is notified by the base station of at least one combination of specific methods through at least one combination of upper layer signaling, MAC-CE signaling, and L1 signaling, it may mean that the terminal cannot support one or more other combinations of methods. For example, if the terminal does not receive the above-described DMRS configuration, the terminal may expect that [Method 3-1] is fixedly defined in the standard for DMRS transmission and reception. As another example, the terminal may be notified from the base station about the above [Method 3-2] through a combination of at least one of upper layer signaling, MAC-CE signaling, and L1 signaling, and in this case, the terminal may consider that it has been notified by the base station that the above [Method 3-1] is not supported.

[0596] The terminal may report to the base station, based on the terminal capability, whether it can support at least one combination of [Method 3-1] to [Method 3-4]. In this case, if the terminal reports to the base station, based on the terminal capability, that a combination of one or more specific methods can be supported, it may be regarded as the terminal reporting that it cannot support one or more other combinations of methods. For example, the terminal may report to the base station, based on the terminal capability, whether it can support [Method 3-1]. As another example, the terminal may report to the base station, based on the terminal capability, that it can support [Method 3-2], and this terminal capability report may mean that the terminal cannot support [Method 3-1].

[0597] The terminal may report to the base station its capability to support the enhanced DMRS type 1 and / or enhanced DMRS type 2 and DCI format 0_3 and / or 1_3 simultaneously. That is, when the terminal receives DCI format 0_3 or 1_3 from the base station, the terminal may be instructed to support the enhanced DMRS type 1 or enhanced DMRS type 2 through the antenna port field in the corresponding DCI format 0_3 or 1_3.

[0598] The terminal capabilities reported by the terminal can be defined in various forms as shown below and in examples.

[0599] - As an example, the terminal capability may be to support DCI format 1_3 and enhanced DMRS type 1 simultaneously.

[0600] - As an example, the terminal capability may be to support DCI format 1_3 and enhanced DMRS type 2 simultaneously.

[0601] - As an example, the terminal capability may be to support DCI format 0_3 and enhanced DMRS type 1 simultaneously.

[0602] - As an example, the terminal capability may be to support DCI format 0_3 and enhanced DMRS type 2 simultaneously.

[0603] - As an example, the terminal capability may be to support DCI format 1_3 and enhanced DMRS type 1 or / and enhanced DMRS type 2 simultaneously. That is, the terminal may report, through the terminal capability, that it can simultaneously support DCI format 1_3 and enhanced DMRS type 1, or simultaneously support DCI format 1_3 and enhanced DMRS type 2. Alternatively, the terminal may select and report, through the terminal capability, one of: simultaneous support of DCI format 1_3 and enhanced DMRS type 1, simultaneous support of DCI format 1_3 and enhanced DMRS type 2, or simultaneous support of DCI format 1_3 and enhanced DMRS type 1 and DMRS type 2.

[0604] - As an example, the terminal capability may be to support DCI format 0_3 and enhanced DMRS type 1 or / and enhanced DMRS type 2 simultaneously. That is, the terminal may report, through the terminal capability, that it can simultaneously support DCI format 0_3 and enhanced DMRS type 1, or simultaneously support DCI format 0_3 and enhanced DMRS type 2. Alternatively, the terminal may select and report, through the terminal capability, one of: simultaneous support of DCI format 0_3 and enhanced DMRS type 1, simultaneous support of DCI format 0_3 and enhanced DMRS type 2, or simultaneous support of DCI format 0_3 and enhanced DMRS type 1 and DMRS type 2.

[0605] - As an example, the terminal capability may be to support DCI format 0_3 and / or DCI format 1_3 and enhanced DMRS type 1 and / or enhanced DMRS type 2 simultaneously. That is, the terminal capability may report that the terminal can simultaneously support DCI format 1_3 and enhanced DMRS type 1, DCI format 1_3 and enhanced DMRS type 2, DCI format 0_3 and enhanced DMRS type 1, and DCI format 0_3 and enhanced DMRS type 2 simultaneously. Alternatively, the terminal may select and report one of the following through the terminal capability: simultaneous support of DCI format 1_3 and enhanced DMRS type 1, simultaneous support of DCI format 1_3 and enhanced DMRS type 2, simultaneous support of DCI format 1_3 and enhanced DMRS type 1 and DMRS type 2, and simultaneous support of DCI format 0_3 and enhanced DMRS type 1, simultaneous support of DCI format 0_3 and enhanced DMRS type 2, simultaneous support of DCI format 0_3 and enhanced DMRS type 1 and DMRS type 2.

[0606] The UE may receive dmrs-DownlinkForPDSCH-MappingTypeA or / and dmrs-DownlinkForPDSCH-MappingTypeB in the upper layer signaling PDSCH-config. dmrs-DownlinkForPDSCH-MappingTypeA or / and dmrs-DownlinkForPDSCH-MappingTypeB can be used in DCI formats 1_1 and 1_3.

[0607] Accordingly, if the terminal receives dmrs-TypeEnh-r18 as enabled in the upper layer signaling dmrs-DownlinkForPDSCH-MappingTypeA or / and dmrs-DownlinkForPDSCH-MappingTypeB, the terminal may interpret the antenna port field as enhanced DMRS type 1 or enhanced DMRS type 2 when receiving DCI format 1_1, and the terminal may ignore the dmrs-TypeEnh-r18 value and interpret the antenna port field in DCI format 1_3 as DMRS type 1 or DMRS type 2 when receiving DCI format 1_3.

[0608] The UE may receive dmrs-DownlinkForPDSCH-MappingTypeA or / and dmrs-DownlinkForPDSCH-MappingTypeB in the upper layer signaling PDSCH-config. dmrs-DownlinkForPDSCH-MappingTypeA or / and dmrs-DownlinkForPDSCH-MappingTypeB can be used in DCI formats 1_1 and 1_3.

[0609] Therefore, if the terminal has dmrs-TypeEnh-r18 set to enabled in the upper layer signaling dmrs-DownlinkForPDSCH-MappingTypeA or / and dmrs-DownlinkForPDSCH-MappingTypeB,

[0610] - If the terminal does not report the above terminal capability (one of the above terminal capabilities indicating simultaneous support of enhanced DMRS type and DCI format 0_3 / 1_3) to the base station, and the terminal receives DCI format 1_1 and 1_3, the terminal may interpret the antenna port field in DCI format 1_1 as enhanced DMRS type 1 or enhanced DMRS type 2, and may interpret the antenna port field in DCI format 1_3 as DMRS type 1 or DMRS type 2.

[0611] - If the terminal reports the above terminal capability (one of the above terminal capabilities indicating simultaneous support between enhanced DMRS type and DCI format 0_3 / 1_3) to the base station, and the terminal receives DCI format 1_1 and 1_3, the terminal may interpret the antenna port field in DCI format 1_1 and DCI format 1_3 as enhanced DMRS type 1 or enhanced DMRS type 2.

[0612] - If the terminal does not report the terminal capability (one of the terminal capabilities indicating whether to support enhanced DMRS type and DCI format 0_3 / 1_3 simultaneously) to the base station in a band or band combination or feature set including at least one serving cell that can be scheduled with DCI format 1_3, and if the terminal receives antennaPortsDCI1-3-r18 or antennaPortsDCI-1-3-r18 as type1A in MC-DCI-SetOfCells, which is an upper layer signaling, in a serving cell that receives DCI format 1_3, if the terminal receives DCI formats 1_1 and 1_3, the terminal may interpret the antenna port field in DCI format 1_1 as enhanced DMRS type 1 or enhanced DMRS type 2, and may interpret the antenna port field in DCI format 1_3 as DMRS type 1 or DMRS type 2.

[0613] - If the terminal receives antennaPortsDCI1-3-r18 or antennaPortsDCI-1-3-r18 as type 2 in MC-DCI-SetOfCells, which is an upper layer signaling, in a serving cell receiving DCI format 1_3, and if the terminal does not report the terminal capability (one of the terminal capabilities indicating whether to support enhanced DMRS type and DCI format 0_3 / 1_3 simultaneously) for some of one or more cells scheduled with DCI format 1_3, and reports the terminal capability for some of the remaining cells, if the terminal receives DCI formats 1_1 and 1_3, the terminal may interpret the antenna port field in DCI format 1_1 as enhanced DMRS type 1 or enhanced DMRS type 2, and may interpret the antenna port field in DCI format 1_3 as DMRS type 1 or DMRS type 2 for the antenna port field corresponding to a cell for which the terminal capability is not reported, and may interpret the antenna port field corresponding to a cell for which the terminal capability is reported as DMRS type 1 or DMRS type 2. For the antenna port field, it can be interpreted as enhanced DMRS type 1 or enhanced DMRS type 2.

[0614] - If the terminal receives antennaPortsDCI1-3-r18 or antennaPortsDCI-1-3-r18 as type1A in MC-DCI-SetOfCells, which is an upper layer signaling, in a serving cell receiving DCI format 1_3, and if the terminal does not report the terminal capability (one of the terminal capabilities indicating whether to support enhanced DMRS type and DCI format 0_3 / 1_3 simultaneously) for some of one or more cells scheduled with DCI format 1_3, and reports the terminal capability for some of the remaining cells, if the terminal receives DCI formats 1_1 and 1_3, the terminal may interpret the antenna port field in DCI format 1_1 as enhanced DMRS type 1 or enhanced DMRS type 2, and may interpret the antenna port field in DCI format 1_3 as DMRS type 1 or DMRS type 2 for the antenna port field corresponding to the cell for which the terminal capability is not reported, and may transmit the terminal capability to the cell for which the terminal capability is reported. For the corresponding antenna port field, it can be interpreted as enhanced DMRS type 1 or enhanced DMRS type 2.

[0615] FIG. 15 is a diagram showing the operation of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0616] In step 1500, the terminal may transmit terminal capabilities to the base station. The terminal capability signaling that may be reported at this time may be for a combination of at least one of the terminal capabilities related to the DMRS type, the terminal capabilities related to the enhanced DMRS type, the terminal capabilities related to the search space, the terminal capabilities related to the supportable DCI format (for example, DCI formats 1_2, 1_3, 4_2), and the terminal capabilities indicating whether to support the [Method 3-1] to [Method 3-5]. Step 1500 may also be omitted.

[0617] In step 1505, the terminal may receive upper layer signaling from the base station according to the reported terminal capability. At this time, the terminal may receive upper layer signaling for at least one combination of search space-related upper layer signaling, DCI format-related upper layer signaling that can be monitored within each search space, DMRS type and enhanced DMRS type-related upper layer signaling, and upper layer signaling for [Method 3-1] to [Method 3-5] from the base station.

[0618] In step 1510, the terminal may receive a PDCCH from the base station. The PDCCH may include information for scheduling PUSCH transmission or PDSCH reception and may indicate a DMRS port based on a specific DMRS type. If the terminal does not receive a configuration for the DMRS type, the terminal may not receive a DMRS indication via the PDCCH.

[0619] In step 1515, the terminal may transmit a PUSCH or receive a PDSCH and perform DMRS channel estimation. If the terminal does not receive a configuration for a DMRS type, the terminal may determine a DMRS type to consider when receiving a PDSCH or transmitting a PUSCH by considering a combination of at least one of [Method 3-1] to [Method 3-5].

[0620] The above flowchart illustrates exemplary methods that can be implemented according to the principles of the present disclosure, and various modifications may be made to the methods depicted in the flowcharts herein. For example, although depicted as a series of steps, various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other instances, steps may be omitted or replaced with other steps.

[0621] FIG. 16 is a diagram illustrating the operation of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0622] In step 1600, the base station can receive terminal capability from the terminal. The terminal capability signaling that can be reported at this time may be for a combination of at least one of the terminal capability related to the DMRS type, the terminal capability related to the enhanced DMRS type, the terminal capability related to the search space, the terminal capability related to the supportable DCI format (for example, DCI format 1_2, 1_3, 4_2), and the terminal capability indicating whether to support the [Method 3-1] to [Method 3-5]. Step 1600 may also be omitted.

[0623] In step 1605, the base station may transmit upper layer signaling to the terminal according to the received terminal capability. At this time, the base station may set upper layer signaling for at least one combination of search space-related upper layer signaling, DCI format-related upper layer signaling that can be monitored within each search space, DMRS type and enhanced DMRS type-related upper layer signaling, and upper layer signaling for [Method 3-1] to [Method 3-5].

[0624] In step 1610, the base station may transmit a PDCCH to the terminal. The PDCCH may include information scheduling the terminal's PUSCH transmission or PDSCH reception, and may indicate a DMRS port based on a specific DMRS type. If the terminal does not receive a configuration for the DMRS type, the terminal may not receive a DMRS indication via the PDCCH.

[0625] In step 1615, the base station may receive the PUSCH of the terminal and receive the corresponding DMRS to estimate the channel, or transmit the PDSCH to the terminal and transmit the corresponding DMRS. If the terminal does not receive the configuration for the DMRS type, the terminal may determine the DMRS type to be considered when receiving the PDSCH or transmitting the PUSCH by considering at least one combination of [Method 3-1] to [Method 3-5].

[0626] The above flowchart illustrates exemplary methods that can be implemented according to the principles of the present disclosure, and various modifications may be made to the methods depicted in the flowcharts herein. For example, although depicted as a series of steps, various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other instances, steps may be omitted or replaced with other steps.

[0627] FIG. 17 is a diagram illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0628] Referring to FIG. 17, the terminal may include a transceiver, which refers to a terminal receiving unit (1700) and a terminal transmitting unit (1710), a memory (not shown), and a terminal processing unit (1705, or a terminal control unit or processor). Depending on the communication method of the terminal described above, the transceiver units (1700, 1710), the memory, and the terminal processing unit (1705) 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.

[0629] 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.

[0630] 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.

[0631] 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.

[0632] 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.

[0633] FIG. 18 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0634] Referring to FIG. 18, the base station may include a transceiver, which refers to a base station receiver (1800) and a base station transmitter (1810), a memory (not shown), and a base station processor (1805, or a base station control unit or processor). According to the communication method of the base station described above, the transceiver (1800, 1810), the memory, and the base station processor (1805) 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.

[0635] 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.

[0636] 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.

[0637] 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.

[0638] 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.

[0639] 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.

[0640] 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.

[0641] 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.

[0642] 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.

[0643] In the specific embodiments of the present disclosure described above, components included in the embodiments 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.

[0644] 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.

[0645] 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.

[0646] 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.

[0647] 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.

[0648] 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 transmitting capability information indicating that the terminal supports both (i) enhanced DM-RS (demodulation-reference signal) and (ii) DCI (downlink control information) format 1_3; A step of receiving the above DCI format 1_3 through a PDCCH (physical downlink control channel); and A method comprising the step of receiving a PDSCH DM-RS for a PDSCH (physical downlink shared channel) scheduled by the DCI format 1_3, wherein the PDSCH DM-RS is related to the enhanced DM-RS.

2. In paragraph 1, The above improved DM-RS is: For DM-RS type 1, the maximum number of DM-RS ports for a single symbol DM-RS is 8 and the maximum number of DM-RS ports for a double symbol DM-RS is 16; and A method, wherein for DM-RS type 2, the maximum number of DM-RS ports for a single symbol DM-RS is 12 and the maximum number of DM-RS ports for a double symbol DM-RS is 24; 3. In paragraph 1, The above DCI format 1_3 includes an antenna port field, A method in which the reception of the above PDSCH DM-RS is based on the above antenna port field.

4. In paragraph 1, After transmitting the above capability information, the step of receiving, through upper layer signaling, a setting related to the enhanced DM-RS and a setting related to the DCI format 1_3 is further included. A method wherein the reception of the DCI format 1_3 and the reception of the PDSCH DM-RS are performed after receiving the settings related to the enhanced DM-RS and the settings related to the DCI format 1_3.

5. In paragraph 4, The settings related to the above enhanced DM-RS are included in DMRS-DownlinkConfig, method.

6. At the terminal of the communication system, Transmitter and receiver; and A processor connected to the transceiver, the processor comprising: Transmit capability information indicating that the terminal supports both (i) enhanced demodulation-reference signal (DM-RS) and (ii) downlink control information (DCI) format 1_3; Receiving the above DCI format 1_3 through PDCCH (physical downlink control channel); and A terminal configured to receive a PDSCH DM-RS for a PDSCH (physical downlink shared channel) scheduled by the above DCI format 1_3, wherein the PDSCH DM-RS is related to the enhanced DM-RS.

7. In paragraph 6, The above improved DM-RS is: For DM-RS type 1, the maximum number of DM-RS ports for a single symbol DM-RS is 8 and the maximum number of DM-RS ports for a double symbol DM-RS is 16; and For DM-RS type 2, the maximum number of DM-RS ports for single symbol DM-RS is 12 and the maximum number of DM-RS ports for double symbol DM-RS is 24; and the terminal.

8. In paragraph 6, The above DCI format 1_3 includes an antenna port field, The terminal receives the above PDSCH DM-RS based on the antenna port field.

9. In paragraph 6, the processor: After transmitting the above capability information, it is set to receive settings related to the enhanced DM-RS and settings related to the DCI format 1_3 through upper layer signaling, A terminal in which reception of the above DCI format 1_3 and reception of the above PDSCH DM-RS are performed after receiving settings related to the enhanced DM-RS and settings related to the above DCI format 1_3.

10. In paragraph 9, The settings related to the above enhanced DM-RS are included in DMRS-DownlinkConfig, terminal.

11. In a method performed by a base station in a communication system, A step of receiving capability information from a terminal indicating that the terminal supports both (i) enhanced demodulation-reference signal (DM-RS) and (ii) downlink control information (DCI) format 1_3; A step of transmitting the above DCI format 1_3 to the terminal through a PDCCH (physical downlink control channel); and A method comprising the step of transmitting a PDSCH DM-RS for a PDSCH (physical downlink shared channel) scheduled by the DCI format 1_3 to the terminal, wherein the PDSCH DM-RS is related to the enhanced DM-RS.

12. In paragraph 11, The above improved DM-RS is: For DM-RS type 1, the maximum number of DM-RS ports for a single symbol DM-RS is 8 and the maximum number of DM-RS ports for a double symbol DM-RS is 16; and A method, wherein for DM-RS type 2, the maximum number of DM-RS ports for a single symbol DM-RS is 12 and the maximum number of DM-RS ports for a double symbol DM-RS is 24; 13. In paragraph 11, After receiving the above capability information, the step of transmitting, to the terminal, settings related to the enhanced DM-RS and settings related to the DCI format 1_3 through upper layer signaling, A method wherein the reception of the DCI format 1_3 and the reception of the PDSCH DM-RS are performed after receiving the settings related to the enhanced DM-RS and the settings related to the DCI format 1_3.

14. In the base station of the communication system, Transmitter and receiver; and A processor connected to the transceiver, the processor comprising: Receive capability information from the terminal indicating that the terminal supports configuration for both (i) enhanced demodulation-reference signal (DM-RS) and (ii) downlink control information (DCI) format 1_3; Transmitting the above DCI format 1_3 to the terminal through PDCCH (physical downlink control channel); and A base station configured to transmit a PDSCH DM-RS for a PDSCH (physical downlink shared channel) scheduled by the DCI format 1_3 to the terminal, wherein the PDSCH DM-RS is related to the enhanced DM-RS.

15. In paragraph 14, The above improved DM-RS is, For DM-RS type 1, the maximum number of DM-RS ports for a single symbol DM-RS is 8 and the maximum number of DM-RS ports for a double symbol DM-RS is 16; and For DM-RS Type 2, a base station in which the maximum number of DM-RS ports for single symbol DM-RS is 12 and the maximum number of DM-RS ports for double symbol DM-RS is 24;

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