KR20230133743A - Method and apparatus of transmission and reception for data and reference signal in wireless communication systems - Google Patents

Abstract

This disclosure relates to 5G or 6G communication systems to support higher data rates. This 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 data and reference signals in a wireless communication system and a device capable of performing the same.

Description

Method and device for transmitting and receiving data and reference signals in a wireless communication system {METHOD AND APPARATUS OF TRANSMISSION AND RECEPTION FOR DATA AND REFERENCE SIGNAL IN WIRELESS COMMUNICATION SYSTEMS}

This 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 data and reference signals in a wireless communication system and a device capable of performing the same.

5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and includes sub-6 GHz ('Sub 6GHz') bands such as 3.5 gigahertz (3.5 GHz) as well as millimeter wave (mm) bands such as 28 GHz and 39 GHz. It is also possible to implement it in the ultra-high frequency band ('Above 6GHz') called Wave. In addition, in the case of 6G mobile communication technology, which is called the system of Beyond 5G, Terra is working to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low delay time that is reduced to one-tenth. Implementation in Terahertz bands (e.g., 95 GHz to 3 THz) is being considered.

In the early days of 5G mobile communication technology, there were concerns about ultra-wideband services (enhanced Mobile BroadBand, eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC). With the goal of satisfying service support and performance requirements, efficient use of ultra-high frequency resources, including beamforming and massive array multiple input/output (Massive MIMO) to alleviate radio wave path loss in ultra-high frequency bands and increase radio transmission distance. Various numerology support (multiple subcarrier interval operation, etc.) and dynamic operation of slot format, initial access technology to support multi-beam transmission and broadband, definition and operation of BWP (Band-Width Part), large capacity New channel coding methods such as LDPC (Low Density Parity Check) codes for data transmission and Polar Code for highly reliable transmission of control information, L2 pre-processing, and dedicated services specialized for specific services. Standardization of network slicing, etc., which provides networks, has been carried out.

Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology, considering the services that 5G mobile communication technology was intended to support, based on the vehicle's own location and status information. V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience, and NR-U (New Radio Unlicensed), which aims to operate a system that meets 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 the terrestrial network is impossible, positioning, etc. Physical layer standardization for technology is in progress.

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

When this 5G mobile communication system is commercialized, an explosive increase in connected devices will be connected to the communication network. Accordingly, it is expected that strengthening the functions and performance of the 5G mobile communication system and integrated operation of connected devices will be necessary. To this end, eXtended Reality (XR) and Artificial Intelligence are designed to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR). , AI) and machine learning (ML), new research will be conducted on 5G performance improvement and complexity reduction, AI service support, metaverse service support, and drone communication.

In addition, the development of these 5G mobile communication systems includes new waveforms, full dimensional MIMO (FD-MIMO), and array antennas to ensure coverage in the terahertz band of 6G mobile communication technology. , multi-antenna transmission technology such as Large Scale Antenna, metamaterial-based lens and antenna to improve coverage of terahertz band signals, high-dimensional spatial multiplexing technology using OAM (Orbital Angular Momentum), RIS ( In addition to Reconfigurable Intelligent Surface technology, Full Duplex technology, satellite, and AI (Artificial Intelligence) to improve the frequency efficiency of 6G mobile communication technology and system network are utilized from the design stage and end-to-end. -to-End) Development of AI-based communication technology that realizes system optimization by internalizing AI support functions, and next-generation distributed computing technology that realizes services of complexity beyond the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources. It could be the basis for .

As various services can be provided as described above and with the development of wireless communication systems, there is a need for a method to provide these services smoothly.

The disclosed embodiment seeks to provide an apparatus and method that can effectively provide services in a mobile communication system.

The present invention to solve the above problems is a control signal processing method in a wireless communication system, comprising: receiving a first control signal transmitted from a base station; processing the received first control signal; And transmitting a second control signal generated based on the processing to the base station.

The disclosed embodiment provides an apparatus and method that can effectively provide services in a mobile communication system.

1 is a diagram illustrating the basic structure of the time-frequency domain in a wireless communication system according to an embodiment of the present disclosure.
FIG. 2 is a diagram illustrating a frame, subframe, and slot structure in a wireless communication system according to an embodiment of the present disclosure.
FIG. 3 is a diagram illustrating an example of bandwidth portion setting in a wireless communication system according to an embodiment of the present disclosure.
FIG. 4 is a diagram illustrating an example of control area setting of a downlink control channel in a wireless communication system according to an embodiment of the present disclosure.
FIG. 5A is a diagram illustrating the structure of a downlink control channel in a wireless communication system according to an embodiment of the present disclosure.
FIG. 5B is a diagram illustrating through Span a case where a terminal can have multiple PDCCH monitoring positions within a slot in a wireless communication system according to an embodiment of the present disclosure.
FIG. 6 is a diagram illustrating an example of DRX operation in a wireless communication system according to an embodiment of the present disclosure.
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 an embodiment of the present disclosure.
FIG. 8 is a diagram illustrating an example of a TCI state allocation method for PDCCH in a wireless communication system according to an embodiment of the present disclosure.
FIG. 9 is a diagram illustrating a TCI indication MAC CE signaling structure for PDCCH DMRS in a wireless communication system according to an embodiment of the present disclosure.
FIG. 10 is a diagram illustrating an example of beam settings of a control resource set and search space in a wireless communication system according to an embodiment of the present disclosure.
FIG. 11 is a diagram illustrating a method in which a base station and a terminal transmit and receive data in consideration of a downlink data channel and rate matching resources in a wireless communication system according to an embodiment of the present disclosure.
FIG. 12 is a diagram illustrating a method for a terminal to select a set of control resources that can be received in consideration of priority when receiving a downlink control channel in a wireless communication system according to an embodiment of the present disclosure.
FIG. 13 is a diagram illustrating an example of PDSCH frequency axis resource allocation in a wireless communication system according to an embodiment of the present disclosure.
FIG. 14 is a diagram illustrating an example of PDSCH time axis resource allocation in a wireless communication system according to an embodiment of the present disclosure.
FIG. 15 is a diagram illustrating an example of time axis resource allocation according to subcarrier intervals of a data channel and a control channel in a wireless communication system according to an embodiment of the present disclosure.
Figure 16 shows the process for beam setting and activation of PDSCH.
Figure 17 shows an example of MAC-CE structure for PDSCH TCI state activation/deactivation.
FIG. 18 is a diagram illustrating the 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 an embodiment of the present disclosure.
FIG. 19 is a diagram illustrating an example of antenna port configuration and resource allocation for cooperative communication in a wireless communication system according to an embodiment of the present disclosure.
FIG. 20 is a diagram illustrating an example of downlink control information (DCI) configuration for cooperative communication in a wireless communication system according to an embodiment of the present disclosure.
Figure 21 is a diagram showing the Enhanced PDSCH TCI state activation/deactivation MAC-CE structure.
FIG. 22 is a diagram illustrating the structure of a terminal in a wireless communication system according to an embodiment of the present disclosure.
FIG. 23 is a diagram illustrating the structure of a base station in a wireless communication system according to an embodiment of the present disclosure.
Figure 24 is a diagram showing the operation of a terminal to support improved DMRS types 1 and 2 according to an embodiment of the present disclosure.
Figure 25 is a diagram showing the operation of a base station to support improved DMRS types 1 and 2 according to an embodiment of the present disclosure.

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

In describing the embodiments, description of technical content that is well known in the technical field to which this disclosure belongs and that is not directly related to this disclosure will be omitted. This is to convey the gist of the present disclosure more clearly without obscuring it by omitting unnecessary explanation.

For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically shown. Additionally, the size of each component does not entirely reflect its actual size. In each drawing, identical or corresponding components are assigned the same reference numbers.

The advantages and features of the present disclosure and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms, and the present embodiments are merely intended to ensure that the disclosure is complete and are within the scope of common knowledge in the technical field to which the present disclosure pertains. It is provided to fully inform those who have the scope of the disclosure, and the disclosure is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification. Additionally, when describing the present disclosure, if it is determined that a detailed description of a related function or configuration may unnecessarily obscure the gist of the present disclosure, the detailed description will be omitted. In addition, the terms described below are terms defined in consideration of the functions in the present disclosure, and may vary depending on the intention or custom of the user or operator. Therefore, the definition should be made based on the contents throughout this specification.

Hereinafter, the base station is the entity that performs resource allocation for the terminal and may be at least one of gNode B, eNode B, Node B, BS (Base Station), wireless access unit, base station controller, or node on the network. A terminal may include a UE (User Equipment), MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing communication functions. In this 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, embodiments of the present disclosure can also be applied to other communication systems with similar technical background or channel type. For example, this may include the 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A, and the term 5G hereinafter may also include the existing LTE, LTE-A, and other similar services. there is. In addition, this disclosure may be applied to other communication systems through some modifications without significantly departing from the scope of the present disclosure at the discretion of a person with skilled technical knowledge.

At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagram diagrams can be performed by computer program instructions. These computer program instructions can be mounted on a processor of a general-purpose computer, special-purpose computer, or other programmable data processing equipment, so that the instructions performed through the processor of the computer or other programmable data processing equipment are described in the flow chart block(s). It creates the means to perform functions. These computer program instructions may also be stored in computer-usable or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement a function in a particular manner, so that the computer-usable or computer-readable memory It is also possible to produce manufactured items containing instruction means that perform the functions described in the flowchart block(s). Computer program instructions can also be mounted on a computer or other programmable data processing equipment, so that a series of operational steps are performed on the computer or other programmable data processing equipment to create a process that is executed by the computer, thereby generating a process that is executed by the computer or other programmable data processing equipment. Instructions that perform processing equipment may also provide steps for executing the functions described in the flow diagram block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). Additionally, it should be noted that in some alternative execution examples it is possible for the functions mentioned in the blocks to occur out of order. For example, it is possible for two blocks shown in succession to be performed substantially simultaneously, or it is possible for the blocks to be performed in reverse order depending on the corresponding function.

At this time, the term '~unit' used in this embodiment refers to software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and '~unit' performs certain roles. do. However, '~part' is not limited to software or hardware. The '~ part' may be configured to reside in an addressable storage medium and may be configured to reproduce on one or more processors. Therefore, as an example, '~ part' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, 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 may be further separated into additional components and 'parts'. Additionally, components and 'parts' may be implemented to regenerate one or more CPUs within a device or a secure multimedia card. Additionally, in an embodiment, '~ part' may include one or more processors.

Wireless communication systems have moved away from providing early voice-oriented services to, for example, 3GPP's HSPA (High Speed Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), and LTE-Advanced. Broadband wireless that provides high-speed, high-quality packet data services such as communication standards such as (LTE-A), LTE-Pro, 3GPP2's High Rate Packet Data (HRPD), UMB (Ultra Mobile Broadband), and IEEE's 802.16e. It is evolving into a communication system.

As a representative example of the broadband wireless communication system, the LTE system adopts Orthogonal Frequency Division Multiplexing (OFDM) in the downlink (DL), and Single Carrier Frequency Division Multiplexing (SC-FDMA) in the uplink (UL). Access) method is adopted. Uplink refers to a wireless link in which a terminal (UE (User Equipment) or MS (Mobile Station)) transmits data or control signals to a base station (eNode B, or base station (BS)), and downlink refers to a wireless link in which the base station transmits data or control signals to the base station (eNode B, or base station (BS)). It refers to a wireless link that transmits data or control signals. The above multiple access method usually distinguishes each user's data or control information by allocating and operating the time-frequency resources to carry data or control information for each user so that they do not overlap, that is, orthogonality is established. You can.

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

eMBB aims to provide more improved data transmission speeds than those supported by existing LTE, LTE-A or LTE-Pro. For example, in a 5G communication system, eMBB must be able to provide a peak data rate of 20Gbps in the downlink and 10Gbps in the uplink from the perspective of one base station. In addition, the 5G communication system must provide the maximum transmission rate and at the same time provide increased user perceived data rate. In order to meet these requirements, improvements in various transmission and reception technologies are required, including more advanced multi-antenna (Multi Input Multi Output, MIMO) transmission technology. In addition, while LTE transmits signals using a maximum of 20MHz transmission bandwidth in the 2GHz band, the 5G communication system uses a frequency bandwidth wider than 20MHz in the 3~6GHz or above 6GHz frequency band to transmit the data required by the 5G communication system. Transmission speed can be satisfied.

At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. In order to efficiently provide the Internet of Things, mMTC requires support for access to a large number of terminals within a cell, improved coverage of terminals, improved battery time, and reduced terminal costs. Since the Internet of Things provides communication functions by attaching various sensors and various devices, it must be able to support a large number of terminals (for example, 1,000,000 terminals/km2) within a cell. Additionally, due to the nature of the service, terminals that support mMTC are likely to be located in shadow areas that cannot be covered by cells, such as the basement of a building, so they may require wider coverage than other services provided by the 5G communication system. Terminals that support mMTC must be composed of low-cost terminals, and since it is difficult to frequently replace the terminal's battery, a very long battery life time, such as 10 to 15 years, may be required.

Lastly, URLLC is a cellular-based wireless communication service used for a specific purpose (mission-critical). For example, remote control of robots or machinery, industrial automation, unmanned aerial vehicles, remote health care, and emergency situations. Services used for emergency alerts, etc. can be considered. Therefore, the communication provided by URLLC must provide very low latency and very high reliability. For example, a service supporting URLLC must satisfy a wireless access latency (Air interface latency) of less than 0.5 milliseconds and at the same time have a packet error rate requirement of 10 ^-5 or less. Therefore, for services supporting URLLC, the 5G system must provide a smaller Transmit Time Interval (TTI) than other services, and at the same time, a design that requires allocating wide resources in the frequency band to ensure the reliability of the communication link. Specifications may be required.

The three 5G services, namely eMBB, URLLC, and mMTC, can be multiplexed and transmitted in one system. At this time, different transmission/reception techniques and transmission/reception parameters can be used between services to satisfy the different requirements of each service. Of course, 5G is not limited to the three services mentioned above.

[NR time-frequency resource]

Below, the frame structure of the 5G system will be described in more detail with reference to the drawings.

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

The horizontal axis in 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 is defined as 1 OFDM (Orthogonal Frequency Division Multiplexing) symbol 102 on the time axis and 1 subcarrier 103 on the frequency axis. It can be. in the frequency domain (For example, 12) consecutive REs may constitute one resource block (Resource Block, RB, 104).

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

FIG. 2 shows an example of a frame 200, subframe 201, and slot 202 structure. 1 frame (200) can be defined as 10ms. 1 subframe 201 may be defined as 1 ms, and therefore 1 frame 200 may consist of a total of 10 subframes 201. 1 slot (202, 203) can be defined with 14 OFDM symbols (i.e., number of symbols per slot ( )=14). 1 subframe 201 may be composed of one or a plurality of slots 202, 203, and the number of slots 202, 203 per 1 subframe 201 is set to the subcarrier spacing μ(204, 205). ) may vary depending on the condition. In an example of FIG. 2, a case where μ=0 (204) and a case where μ=1 (205) are shown as the subcarrier spacing setting value. When μ=0 (204), 1 subframe 201 may consist of one slot 202, and when μ=1 (205), 1 subframe 201 may consist of two slots 203. It can be composed of . That is, the number of slots per subframe (depending on the setting value μ for the subcarrier spacing) ) may vary, and accordingly, the number of slots per frame ( ) may vary. According to each subcarrier spacing setting μ and Can be defined as Table 1 below.

[Table 1]

[Bandwidth Part (BWP)]

Next, bandwidth part (BWP) settings in the 5G communication system will be described in detail with reference to the drawings.

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

Figure 3 shows an example in which the UE bandwidth 300 is set to two bandwidth parts, that is, bandwidth part #1 (BWP#1) 301 and bandwidth part #2 (BWP#2) 302. It shows. The base station can set one or more bandwidth parts to the terminal, and can set the following information for each bandwidth part.

[Table 2]

Of course, it is not limited to the above example, and in addition to the setting information, various parameters related to the bandwidth can be set to the terminal. The above information can be delivered from the base station to the terminal through higher layer signaling, for example, Radio Resource Control (RRC) signaling. Among the one or multiple bandwidth portions set, at least one bandwidth portion may be activated. Whether to activate the set bandwidth portion can be semi-statically transmitted from the base station to the terminal through RRC signaling or dynamically transmitted through DCI (Downlink Control Information).

According to some embodiments, the terminal before RRC (Radio Resource Control) connection may receive the initial bandwidth portion (Initial BWP) for initial connection from the base station through a MIB (Master Information Block). To be more specific, the terminal may transmit a PDCCH for receiving system information (which may correspond to Remaining System Information; RMSI or System Information Block 1; SIB1) required for initial connection through the MIB in the initial connection stage. You can receive setting information about the control area (Control Resource Set, CORESET) and search space. The control area and search space set as MIB can each be regarded as identifier (ID) 0. The base station can notify the terminal of setting information such as frequency allocation information, time allocation information, and numerology for control area #0 through the MIB. Additionally, the base station can notify the terminal of setting information about the monitoring period and occasion for control area #0, that is, setting information about search space #0, through the MIB. The terminal may regard the frequency area set as control area #0 obtained from the MIB as the initial bandwidth portion for initial access. At this time, the identifier (ID) of the initial bandwidth portion can be regarded as 0.

Setting the bandwidth supported by 5G can be used for various purposes.

According to some embodiments, when the bandwidth supported by the terminal is smaller than the system bandwidth, this can be supported through the bandwidth portion setting. For example, the base station sets the frequency location (setting information 2) of the bandwidth portion to the terminal, allowing the terminal to transmit and receive data at a specific frequency location within the system bandwidth.

Additionally, according to some embodiments, the base station may set a plurality of bandwidth portions to the terminal for the purpose of supporting different numerologies. For example, in order to support both data transmission and reception using a subcarrier spacing of 15kHz and a subcarrier spacing of 30kHz for a certain terminal, the two bandwidth portions can be set to subcarrier spacings of 15kHz and 30kHz, respectively. Different bandwidth portions can be frequency division multiplexed, and when data is to be transmitted and received at a specific subcarrier interval, the bandwidth portion set at the subcarrier interval can be activated.

Additionally, according to some embodiments, for the purpose of reducing power consumption of the terminal, the base station may set bandwidth portions with different sizes of bandwidth to the terminal. For example, if the terminal supports a very large bandwidth, for example, 100 MHz, and always transmits and receives data through that bandwidth, very large power consumption may occur. In particular, monitoring unnecessary downlink control channels with a large bandwidth of 100 MHz in a situation where there is no traffic can be very inefficient in terms of power consumption. For the purpose of reducing power consumption of the terminal, the base station may set a relatively small bandwidth portion of the terminal, for example, a bandwidth portion of 20 MHz. 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, data can be transmitted and received in the 100 MHz bandwidth portion according to the instructions of the base station.

In the method of configuring the bandwidth part, terminals before RRC connection can receive configuration information about the initial bandwidth part through a Master Information Block (MIB) in the initial connection stage. To be more specific, the terminal has a control area (Control Resource Set) for the downlink control channel where DCI (Downlink Control Information) scheduling SIB (System Information Block) can be transmitted from the MIB of PBCH (Physical Broadcast Channel). CORESET) can be set. The bandwidth of the control area set as MIB can be considered as the initial bandwidth part, and through the set initial bandwidth part, the terminal can receive the PDSCH (Physical Downlink Shared Channel) through which the SIB is transmitted. In addition to receiving SIB, the initial bandwidth portion can also be used for other system information (OSI), paging, and random access.

[Bandwidth part (BWP) change]

If one or more bandwidth parts are configured for the terminal, the base station may instruct the terminal to change (or switch, transition) the bandwidth portion using the Bandwidth Part Indicator field in the DCI. As an example, in Figure 3, if the currently activated bandwidth portion of the terminal is bandwidth portion #1 (301), the base station may indicate bandwidth portion #2 (302) to the terminal as a bandwidth portion indicator in the DCI, and the terminal may indicate the received bandwidth portion #2 (302). Bandwidth part change can be performed using bandwidth part #2 (302) indicated by the bandwidth part indicator in DCI.

As described above, since the DCI-based bandwidth portion change can be indicated by the DCI scheduling the PDSCH or PUSCH, when the UE receives a bandwidth portion change request, the PDSCH or PUSCH scheduled by the corresponding DCI may be unreasonable in the changed bandwidth portion. It must be possible to perform reception or transmission without it. For this purpose, the standard stipulates requirements for the delay time (T _BWP ) required when changing the bandwidth portion, and can be defined, for example, as follows.

[Table 3]

Requirements for bandwidth change delay time support type 1 or type 2 depending on the terminal's capability. The terminal can report the supportable bandwidth portion delay time type to the base station.

According to the requirements for the bandwidth portion change delay described above, when the terminal receives a DCI including a bandwidth portion change indicator in slot n, the terminal changes to the new bandwidth portion indicated by the bandwidth portion change indicator in slot n+ It can be completed no later than T _BWP , and transmission and reception on the data channel scheduled by the relevant DCI can be performed in the new changed bandwidth portion. When the base station wants to schedule a data channel with a new bandwidth portion, it can determine time domain resource allocation for the data channel by considering the bandwidth portion change delay time (T _BWP ) of the terminal. That is, when scheduling a data channel with a new bandwidth portion, the base station can schedule the data channel after the bandwidth portion change delay time in determining time domain resource allocation for the data channel. Accordingly, the terminal may not expect that the DCI indicating a bandwidth portion change indicates a slot offset (K0 or K2) value that is smaller than the bandwidth portion change delay time (T _BWP ).

If the terminal receives a DCI indicating a change in the bandwidth portion (for example, DCI format 1_1 or 0_1), the terminal receives the time domain resource allocation indicator field within the DCI from the third symbol of the slot in which the PDCCH including the corresponding DCI was received. No transmission or reception may be performed during the time interval corresponding to the start point of the slot indicated by the slot offset (K0 or K2) value indicated by . For example, if the terminal receives a DCI indicating a change in the bandwidth portion in slot n, and the slot offset value indicated by the corresponding DCI is K, the terminal starts from the third symbol of slot n to the symbols before slot n+K (i.e., slot No transmission or reception may be performed until the last symbol of n+K-1.

[SS/PBCH block]

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

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

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

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

- PBCH: Provides essential system information necessary for transmitting and receiving data channels and control channels of the terminal. Essential system information may include search space-related control information indicating radio resource mapping information of the control channel, scheduling control information for a separate data channel transmitting system information, etc.

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

The terminal can detect PSS and SSS in the initial access stage and decode the PBCH. The MIB can be obtained from the PBCH, and the control area (Control Resource Set; CORESET) #0 (which may correspond to a control area with a control area index of 0) can be set from this. The terminal can perform monitoring on control area #0 assuming that the selected SS/PBCH block and the demodulation reference signal (DMRS) transmitted in control area #0 are QCL (Quasi Co Location). The terminal can receive system information through downlink control information transmitted from control area #0. The terminal can obtain RACH (Random Access Channel)-related configuration information necessary for initial access from the received system information. The terminal can transmit PRACH (Physical RACH) to the base station in consideration of the SS/PBCH index selected, and the base station receiving the PRACH can obtain information about the SS/PBCH block index selected by the terminal. The base station can know which block the terminal has selected among each SS/PBCH block and monitor the control area #0 associated with it.

[DRX]

Figure 6 is a diagram for explaining DRX (Discontinuous Reception).

DRX (Discontinuous Reception) is an operation in which a terminal using a service receives data discontinuously in an RRC Connected state where a radio link is established between the base station and the terminal. When DRX is applied, the terminal can turn on the receiver at a specific point in time to monitor the control channel, and if no data is received for a certain period of time, turn off the receiver to reduce power consumption of the terminal. DRX operation can be controlled by the MAC layer device based on various parameters and timers.

Referring to FIG. 6, Active time 605 is the time when the terminal wakes up every DRX cycle and monitors the PDCCH. Active time (605) can be defined as follows.

- drx-onDurationTimer or drx-InactivityTimer or drx-RetransmissionTimerDL or drx-RetransmissionTimerUL or ra-ContentionResolutionTimer is running; or

- a Scheduling Request is sent on PUCCH and is pending; or

- a PDCCH indicating a new transmission addressed to the C-RNTI of the MAC entity has not been received after successful reception of a Random Access Response for the Random Access Preamble not selected by the MAC entity among the contention-based Random Access Preamble

drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, ra-ContentionResolutionTimer, etc. are timers whose values are set by the base station, and have a function that sets the terminal to monitor the PDCCH when a certain condition is satisfied. Have.

drx-onDurationTimer(615) is a parameter to set the minimum time the terminal is awake in the DRX cycle. drx-InactivityTimer (620) is a parameter for setting the additional awake time of the terminal when receiving (630) a PDCCH indicating new uplink or downlink transmission. drx-RetransmissionTimerDL is a parameter for setting the maximum time that the terminal is awake to receive downlink retransmission in the downlink HARQ procedure. drx-RetransmissionTimerUL is a parameter for setting the maximum time that the terminal is awake to receive an uplink retransmission grant in the uplink HARQ procedure. drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, and drx-RetransmissionTimerUL can be set to, for example, time, number of subframes, number of slots, etc. ra-ContentionResolutionTimer is a parameter for monitoring PDCCH in the random access procedure.

inActive time (610) is the time set not to monitor the PDCCH or/or receive the PDCCH during DRX operation. The remaining time excluding Active time (605) from the total time performing the DRX operation is inActive time. It could be (610). If the terminal does not monitor the PDCCH during Active time (605), it can enter a sleep or inActive state to reduce power consumption.

The DRX cycle refers to the cycle in which the terminal wakes up and monitors the PDCCH. In other words, it means the time interval or on duration occurrence period until the terminal monitors the next PDCCH after monitoring the PDCCH. There are two types of DRX cycle: short DRX cycle and long DRX cycle. Short DRX cycle can be applied as an option.

Long DRX cycle (625) is the longer cycle of the two DRX cycles set in the terminal. While operating in Long DRX, the terminal starts drx-onDurationTimer (615) again when Long DRX cycle (625) has elapsed from the starting point (e.g., start symbol) of drx-onDurationTimer (615). When operating in the Long DRX cycle (625), the terminal can start drx-onDurationTimer (615) in the slot after drx-SlotOffset in a subframe that satisfies Equation 1 below. Here, drx-SlotOffset means the delay before starting drx-onDurationTimer (615). drx-SlotOffset can be set to, for example, time, number of slots, etc.

[Equation 1]

[(SFN

At this time, drx-LongCycleStartOffset can be used to define the subframe in which to start the Long DRX cycle (625) and drx-StartOffset can be used to define the subframe in which to start the Long DRX cycle (625). drx-LongCycleStartOffset can be set to, for example, time, number of subframes, number of slots, etc.

[PDCCH: DCI-related]

Next, downlink control information (DCI) in the 5G system will be described in detail.

In the 5G system, scheduling information for uplink data (or Physical Uplink Shared Channel, PUSCH) or downlink data (or Physical Downlink Shared Channel, PDSCH) is transmitted through DCI. It is transmitted from the base station to the terminal. The terminal can monitor the DCI format for fallback and the DCI format for non-fallback for PUSCH or PDSCH. The countermeasure DCI format may consist of fixed fields predefined between the base station and the terminal, and the non-contrast DCI format may include configurable fields.

DCI can be transmitted through PDCCH (Physical Downlink Control Channel), a physical downlink control channel, through channel coding and modulation processes. A CRC (Cyclic Redundancy Check) is attached to the DCI message payload, and the CRC can be scrambled with an RNTI (Radio Network Temporary Identifier) corresponding to the terminal's identity. Different RNTIs may be used depending on the purpose of the DCI message, for example, UE-specific data transmission, power control command, or random access response. In other words, the RNTI is not transmitted explicitly but is transmitted included in the CRC calculation process. When receiving a DCI message transmitted on the PDCCH, the terminal checks the CRC using the allocated RNTI, and if the CRC check result is correct, the terminal can know that the message was sent to the terminal.

For example, DCI scheduling PDSCH for system information (SI) may be scrambled with SI-RNTI. The DCI that schedules the PDSCH for a Random Access Response (RAR) message can be scrambled with RA-RNTI. DCI scheduling PDSCH for paging messages can be scrambled with P-RNTI. DCI notifying SFI (Slot Format Indicator) can be scrambled with SFI-RNTI. DCI notifying TPC (Transmit Power Control) can be scrambled with TPC-RNTI. The DCI scheduling the UE-specific PDSCH or PUSCH may be scrambled with C-RNTI (Cell RNTI).

DCI format 0_0 can be used as a fallback DCI for scheduling PUSCH, and at this time, CRC can be scrambled with C-RNTI. DCI format 0_0, in which the CRC is scrambled with C-RNTI, may include, for example, the following information.

[Table 4]

DCI format 0_1 can be used as a fallback DCI for scheduling PUSCH, and at this time, CRC can be scrambled with C-RNTI. DCI format 0_1, in which the CRC is scrambled with C-RNTI, may include, for example, the following information.

[Table 5]

DCI format 1_0 can be used as a fallback DCI for scheduling PDSCH, and at this time, CRC can be scrambled with C-RNTI. DCI format 1_0, in which the CRC is scrambled with C-RNTI, may include, for example, the following information.

[Table 6]

DCI format 1_1 can be used as a fallback DCI for scheduling PDSCH, and at this time, CRC can be scrambled with C-RNTI. DCI format 1_1, in which the CRC is scrambled with C-RNTI, may include, for example, the following information.

[Table 7]

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

In the following, the downlink control channel in the 5G communication system will be described in more detail with reference to the drawings.

FIG. 4 is a diagram illustrating an example of a control area (Control Resource Set, CORESET) where a downlink control channel is transmitted in a 5G wireless communication system. Figure 4 shows the UE bandwidth part 410 on the frequency axis and two control areas (control area #1 (401), control area #2 (402)) within one slot (420) on the time axis. An example is shown. The control areas 401 and 402 can be set to a specific frequency resource 403 within the entire terminal bandwidth portion 410 on the frequency axis. The time axis can be set to one or multiple OFDM symbols and can be defined as the control region length (Control Resource Set Duration, 404). Referring to the example shown in FIG. 4, control area #1 (401) is set to a control area length of 2 symbols, and control area #2 (402) is set to a control area length of 1 symbol.

The control area in 5G described above can be set by the base station to the terminal through higher layer signaling (e.g., system information, master information block (MIB), and radio resource control (RRC) signaling). Setting a control area to a terminal means providing information such as the control area identifier (Identity), the frequency location of the control area, and the symbol length of the control area. For example, it may include the following information.

[Table 8]

In Table 8, the tci-StatesPDCCH (simply named TCI (Transmission Configuration Indication) state) configuration information is one or more SS (Synchronization Signals) in a QCL (Quasi Co Located) relationship with the DMRS transmitted from the corresponding control area. /May include information of a Physical Broadcast Channel (PBCH) block index or a Channel State Information Reference Signal (CSI-RS) index.

FIG. 5A is a diagram showing an example of the basic units of time and frequency resources constituting a downlink control channel that can be used in 5G. According to Figure 5a, the basic unit of time and frequency resources constituting the control channel can be called REG (Resource Element Group, 503), and REG (503) is 1 OFDM symbol 501 on the time axis and 1 PRB on the frequency axis. (Physical Resource Block, 502), that is, it can be defined as 12 subcarriers. The base station can configure a downlink control channel allocation unit by concatenating REGs 503.

As shown in FIG. 5A, 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 may be composed of a plurality of REGs 503. Taking REG 503 shown in FIG. 5A as an example, REG 503 may be composed of 12 REs, and if 1 CCE 504 is composed of 6 REGs 503, 1 CCE 504 may consist of 72 REs. When a downlink control area is set, the area can be composed of a plurality of CCEs (504), and a specific downlink control channel is composed of one or multiple CCEs (504) depending on the aggregation level (AL) within the control area. It can be mapped and transmitted. CCEs 504 in the control area are classified by numbers, and at this time, the numbers of CCEs 504 can be assigned according to a logical mapping method.

The basic unit of the downlink control channel shown in FIG. 5A, that is, REG 503, may include both REs to which DCI is mapped and an area to which DMRS 505, a reference signal for decoding the same, is mapped. As shown in FIG. 5A, three DMRSs 505 can be transmitted within 1 REG 503. The number of CCEs required to transmit the PDCCH can be 1, 2, 4, 8, or 16 depending on the aggregation level (AL), and the different numbers of CCEs allow link adaptation of the downlink control channel. It can be used to implement. For example, when AL=L, one downlink control channel can 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. The search space is a set of downlink control channel candidates consisting of CCEs that the terminal must attempt to decode on a given aggregation level, and various aggregations that make one bundle of 1, 2, 4, 8, or 16 CCEs. Because there are levels, the terminal can have multiple search spaces. A search space set can be defined as a set of search spaces at all set aggregation levels.

Search space can be classified into common search space and UE-specific search space. 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 or paging messages for system information. For example, PDSCH scheduling allocation information for SIB transmission, including cell operator information, etc., can be received by examining the common search space of the PDCCH. In the case of a common search space, a certain group of UEs or all UEs must receive the PDCCH, so it can be defined as a set of pre-arranged CCEs. Scheduling allocation information for a UE-specific PDSCH or PUSCH can be received by examining the UE-specific search space of the PDCCH. The terminal-specific search space can be terminal-specifically defined as a function of the terminal's identity and various system parameters.

In 5G, parameters for the search space for PDCCH can be set from the base station to the terminal through higher layer signaling (eg, SIB, MIB, RRC signaling). For example, the base station monitors 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 UE-specific search space), The combination of the DCI format and RNTI to be monitored in the search space, the control area index to be monitored in the search space, etc. can be set to the terminal. For example, it may include the following information.

[Table 9]

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

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

In the common search space, the combination of the following DCI format and RNTI can be monitored. Of course, this is not limited to the examples below.

- 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

- DCI format 2_0 with CRC scrambled by SFI-RNTI

- DCI format 2_1 with CRC scrambled by INT-RNTI

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

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

In the terminal-specific search space, the combination of the following DCI format and RNTI can be monitored. Of course, this is not limited to the examples below.

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

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

The specified RNTIs may follow the definitions and uses below.

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

TC-RNTI (Temporary Cell RNTI): For UE-specific PDSCH scheduling

CS-RNTI (Configured Scheduling RNTI): Semi-statically configured UE-specific PDSCH scheduling purpose

RA-RNTI (Random Access RNTI): Used for PDSCH scheduling in the random access stage

P-RNTI (Paging RNTI): PDSCH scheduling purpose where paging is transmitted

SI-RNTI (System Information RNTI): PDSCH scheduling purpose where system information is transmitted

INT-RNTI (Interruption RNTI): Used to inform whether or not the PDSCH is pucturing.

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

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

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

The DCI formats specified above may follow the definitions below.

[Table 10]

In 5G, the search space of the aggregation level L in the control area p and search space set s can be expressed as Equation 2 below.

[Equation 2]

- : Aggregation level

- : Carrier index

- : Total number of CCEs existing in control area p

- : slot index

- : Number of PDCCH candidates at aggregation level L

- = 0, ..., -1: PDCCH candidate index of aggregation level L

- = 0, ..., -One

- , , , , ,

- : Terminal identifier

The value may correspond to 0 in the case of a common search space.

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

In 5G, as a plurality of search space sets may be set with different parameters (e.g., parameters in Table 9), the set of search space sets monitored by the terminal at each time point may vary. For example, if search space set #1 is set to an X-slot period, search space set #2 is set to a Y-slot period, and Both space set #2 can be monitored, and in a specific slot, either search space set #1 or search space set #2 can be monitored.

[PDCCH: span]

The UE can perform UE capability reporting at each subcarrier interval for cases where it has multiple PDCCH monitoring positions within a slot, and in this case, the concept of Span can be used. Span refers to consecutive symbols through which the UE can monitor the PDCCH within a slot, and each PDCCH monitoring position is within one Span. Span can be expressed as (X,Y), where x refers to the minimum number of symbols that must be separated between the first symbols of two consecutive spans, and Y is the number of consecutive symbols that can monitor the PDCCH within one span. says At this time, the terminal can monitor the PDCCH within the span from the first symbol of the span to the Y symbol.

FIG. 5b is a diagram illustrating through Span a case where a terminal can have multiple PDCCH monitoring positions within a slot in a wireless communication system. Span can be (X,Y) = (7,3), (4,3), (2,2), and in the three cases, each is (5-1-00) and (5-1-05) in Figure 5b. ), expressed as (5-1-10). For example, (5-1-00) represents the case where two spans that can be expressed as (7,4) exist within the slot. The interval between the first symbols of two spans is expressed as indicates the presence of each. As another example, (5-1-05) expresses the case where a total of three spans that can be expressed as (4,3) exist within the slot, and the interval between the second and third spans is greater than It is indicated that it is separated by a large

[PDCCH: Terminal capability report]

The slot location where the above-mentioned common search space and terminal-specific search space are located is indicated by the monitoringSymbolsWitninSlot parameter in Table 11-1, and the symbol position within the slot is indicated as a bitmap through the monitoringSymbolsWithinSlot parameter in Table 9. Meanwhile, the symbol position within the slot where the UE can monitor the search space can be reported to the base station through the following UE capabilities.

- Terminal capability 1 (hereinafter expressed as FG 3-1). This terminal capability is as shown in Table 9a below, if there is one monitoring location (MO: monitoring occasion) for the type 1 and type 3 common search space or terminal-specific search space in the slot, the corresponding MO location is the first in the slot. 3 When located within the symbol, it means the capability to monitor the corresponding MO. This terminal capability is a mandatory capability that all terminals that support NR must support, and whether or not this capability is supported is not explicitly reported to the base station.

[Table 11-1]

- Terminal Capability 2 (hereinafter expressed as FG 3-2). This terminal capability is as shown in Table 11-2 below, if there is one monitoring location (MO: monitoring occasion) for the common search space or terminal-specific search space in the slot, regardless of where the start symbol location of the MO is. This refers to capabilities that can be monitored. This terminal capability can be optionally supported by the terminal, and whether or not this capability is supported is explicitly reported to the base station.

[Table 11-2]

- Terminal capability 3 (hereinafter expressed as FG 3-5, 3-5a, 3-5b). This terminal capability indicates the pattern of MO that the terminal can monitor when there are multiple monitoring occasions (MOs) in the slot for the common search space or the terminal-specific search space, as shown in Table 11-3 below. do. The above-described pattern consists of the start inter-symbol spacing X between different MOs, and the maximum symbol length Y for one MO. The combination of (X,Y) supported by the terminal may be one or more of {(2,2), (4,3), (7,3)}. This terminal capability can be optionally supported by the terminal, and whether or not this capability is supported and the above-mentioned (X, Y) combination are explicitly reported to the base station.

[Table 11-3]

The terminal may report whether it supports the above-described terminal capability 2 and/or terminal capability 3 and related parameters to the base station. The base station can perform time axis resource allocation for the common search space and UE-specific search space based on the reported UE capabilities. When allocating the resources, the base station can prevent the UE from locating the MO in a location that cannot be monitored.

[PDCCH: BD/CCE limit]

When a plurality of search space sets are set for the terminal, the following conditions can be considered in determining the search space set that the terminal should monitor.

If the terminal has set the value of monitoringCapabilityConfig-r16, which is upper layer signaling, to r15monitoringcapability, the terminal can determine the number of PDCCH candidates that can be monitored and the entire search space (here, the entire search space is the union area of a plurality of search space sets). The maximum value for the number of CCEs constituting the entire CCE set (meaning the entire CCE set) is defined for each slot, and if the value of monitoringCapabilityConfig-r16 is set to r16monitoringcapability, the terminal determines the number of PDCCH candidates that can be monitored and the total search space ( Here, the maximum value for the number of CCEs constituting the entire search space (meaning the entire set of CCEs corresponding to the union area of multiple search space sets) is defined for each span.

[Condition 1: Limit the maximum number of PDCCH candidates]

According to the setting value of upper layer signaling as above, M ^μ , the maximum number of PDCCH candidates that the UE can monitor, is defined on a slot basis in a cell with a subcarrier spacing of 15·2 ^μ kHz, Table 12-1 below. If defined on a Span basis, Table 12-2 below can be followed.

[Table 12-1]

[Table 12-2]

[Condition 2: Limit the maximum number of CCEs]

As described above, according to the setting value of upper layer signaling, C ^μ , the maximum number of CCEs constituting the entire search space (here, the entire search space means the entire set of CCEs corresponding to the union area of a plurality of search space sets) is sub In a cell set to a carrier spacing of 15·2 ^μ kHz, when defined on a slot basis, Table 12-3 below can be followed, and when defined on a Span basis, Table 12-4 below can be followed.

[Table 12-3]

[Table 12-4]

For convenience of explanation, a situation in which both conditions 1 and 2 above are satisfied at a specific point in time will be defined as “condition A.” Therefore, not satisfying condition A may mean not satisfying at least one of conditions 1 and 2 above.

[PDCCH: Overbooking]

Depending on the settings of the base station's search space sets, conditions A may not be satisfied at a specific point in time. If condition A is not satisfied at a specific point in time, the terminal can select and monitor only some of the search space sets set to satisfy condition A at that point in time, and the base station can transmit the PDCCH to the selected search space set.

The following method can be followed to select some search spaces from the entire set of search spaces.

If condition A for PDCCH is not satisfied at a specific time point (slot), the terminal (or the base station) selects a search space set whose search space type is set to common search space among the search space sets that exist at that time point to the terminal. -You can select a specific search space over a set of search spaces set as a specific search space.

When all search space sets set as common search spaces are selected (i.e., if condition A is satisfied even after selecting all search spaces set as common search spaces), the terminal (or base station) uses the terminal-specific search space. You can select search space sets that are set to . At this time, if there are multiple search space sets set as terminal-specific search spaces, a search space set with a lower search space set index may have higher priority. Considering priority, terminal-specific search space sets can be selected within the range where condition A is satisfied.

[QCL, TCI state]

In a wireless communication system, one or more different antenna ports (or one or more channels, signals, and combinations thereof may be replaced, but in the future description of the present disclosure, they will be collectively referred to as different antenna ports for convenience) They can be associated with each other by QCL (Quasi co-location) settings as shown in [Table 10] below. The TCI state is to announce the QCL relationship between PDCCH (or PDCCH DMRS) and other RSs or channels, and the QCL relationship between a reference antenna port A (reference RS #A) and another target antenna port B (target RS #B) QCLed means that the terminal is allowed to apply some or all of the large-scale channel parameters estimated at antenna port A to channel measurement from antenna port B. QCL is based on 1) time tracking affected by average delay and delay spread, 2) frequency tracking affected by Doppler shift and Doppler spread, 3) RRM (radio resource management) affected by average gain, and 4) spatial parameter. Depending on the situation, such as the affected BM (beam management), it may be necessary to associate different parameters. Accordingly, NR supports four types of QCL relationships as shown in Table 13 below.

[Table 13]

The spatial RX parameter is 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, spatial channel correlation, etc. Some or all of them can be collectively referred to.

The QCL relationship can be set to the terminal through RRC parameters TCI-State and QCL-Info as shown in Table 14 below. Referring to Table 14, the base station can set one or more TCI states to the UE and inform the UE of up to two QCL relationships (qcl-Type1, qcl-Type2) for the RS referring to the ID of the TCI state, that is, the target RS. . At this time, each QCL information (QCL-Info) included in each TCI state includes the serving cell index and BWP index of the reference RS indicated by the QCL information, the type and ID of the reference RS, and the QCL type as shown in Table 13 above. do.

[Table 14]

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 about N different beams to the terminal through N different TCI states. For example, when N = 3 as shown in FIG. 7, the base station is associated with CSI-RS or SSB corresponding to beams in which the qcl-Type2 parameter included in the three TCI states (700, 705, 710) is different, and QCL type D By setting it to , it can be announced that the antenna ports referring to the different TCI states 700, 705, or 710 are associated with different spatial Rx parameters, that is, different beams.

Tables 15-1 to 15-5 below show valid TCI state settings according to target antenna port type.

Table 15-1 shows valid TCI state settings when the target antenna port is CSI-RS for tracking (TRS). The TRS refers to an NZP CSI-RS in which the repetition parameter among CSI-RSs is not set and trs-Info is set to true. Setting number 3 in Table 15-1 can be used for aperiodic TRS.

[Table 15-1] Valid TCI state settings when the target antenna port is CSI-RS for tracking (TRS)

Table 15-2 shows valid TCI state settings when the target antenna port is 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) among CSI-RSs is not set and trs-Info is also not set to true.

[Table 15-2] Valid TCI state settings when the target antenna port is CSI-RS for CSI

Table 15-3 shows valid TCI state settings when the target antenna port is CSI-RS for beam management (BM, same meaning as CSI-RS for L1 RSRP reporting). The CSI-RS for BM refers to an NZP CSI-RS in which the repetition parameter among CSI-RSs is set and has a value of On or Off, and trs-Info is not set to true.

[Table 15-3] Valid TCI state settings when the target antenna port is CSI-RS for BM (for L1 RSRP reporting)

Table 15-4 shows valid TCI state settings when the target antenna port is PDCCH DMRS.

[Table 15-4] Valid TCI state settings when the target antenna port is PDCCH DMRS

Table 15-5 shows valid TCI state settings when the target antenna port is PDSCH DMRS.

[Table 15-5] Valid TCI state settings when the target antenna port is PDSCH DMRS

The representative QCL setting method according to Tables 15-1 to 15-5 above changes the target antenna port and reference antenna port for each step from "SSB" -> "TRS" -> "CSI-RS for CSI, or CSI-RS for BM. , or PDCCH DMRS, or PDSCH DMRS”. Through this, it is possible to assist the terminal's reception operation by linking the statistical characteristics that can be measured from SSB and TRS to each antenna port.

[PDCCH: TCI state related]

Specifically, the TCI state combinations applicable to the PDCCH DMRS antenna port are shown in Table 16 below. The fourth row in Table 16 is the combination assumed by the terminal before RRC setting, and setting after RRC is not possible.

[Table 16]

NR supports a hierarchical signaling method as shown in FIG. 8 for dynamic allocation of PDCCH beams. Referring to FIG. 8, the base station can set N TCI states (805, 810, ..., 820) to the terminal through RRC signaling 800, and some of these can be set as TCI states for CORESET. (825). Afterwards, the base station may indicate one of the TCI states (830, 835, 840) for CORESET to the UE through MAC CE signaling (845). Afterwards, the terminal receives the PDCCH based on the beam information included in the TCI state indicated by the MAC CE signaling.

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), including a 5-bit serving cell ID (915), a 4-bit CORESET ID (920), and a 7-bit TCI state. Includes ID 925.

FIG. 10 is a diagram illustrating an example of beam settings of a control resource set (CORESET) and a search space according to the above description. Referring to FIG. 10, the base station may indicate one of the TCI state lists included in the CORESET (1000) configuration through MAC CE signaling (1005). Afterwards, until another TCI state is indicated to the corresponding CORESET through another MAC CE signaling, the terminal provides the same QCL information (beam #1, 1005) in one or more search spaces (1010, 1015, 1020) connected to the CORESET. is considered to apply. The PDCCH beam allocation method described above is difficult to indicate a beam change faster than the MAC CE signaling delay, and also has the disadvantage of applying the same beam to each CORESET regardless of search space characteristics, making flexible PDCCH beam operation difficult. There is. The following embodiments of the present invention provide a more flexible PDCCH beam setting and operation method. Hereinafter, in describing embodiments of the present invention, several distinct examples are provided for convenience of explanation, but these are not mutually exclusive and can be applied in appropriate combination with each other depending on the situation.

The base station can set one or more TCI states for a specific control area to the terminal, and can activate one of the set TCI states through a MAC CE activation command. For example, {TCI state#0, TCI state#1, TCI state#2} is set as the TCI state in control area #1, and the base station sets the TCI state as the TCI state for control area #1 through MAC CE. A command to activate to assume #0 can be sent to the terminal. The terminal can correctly receive the DMRS of the corresponding control area based on the activation command for the TCI state received through MAC CE and the QCL information in the activated TCI state.

For the control area (control area #0) whose index is set to 0, if the terminal does not receive the MAC CE activation command for the TCI state of control area #0, the terminal responds to the DMRS transmitted from control area #0. It can be assumed that it is QCLed with the SS/PBCH block identified during the initial access process or a non-contention-based random access process that is not triggered by a PDCCH command.

For a control area (control area #X) whose index is set to a value other than 0, if the terminal has not received a TCI state for control area # If the MAC CE activation command is not received, the terminal can assume that the DMRS transmitted in control area #X has been QCLed with the SS/PBCH block identified during the initial access process.

[PDCCH: QCL prioritization rule related]

In the following, the QCL priority determination operation for PDCCH will be described in detail.

The terminal operates in a single cell or intra-band carrier aggregation, and multiple control resource sets that exist within the activated bandwidth portion of a single or multiple cells have the same or different QCL-TypeD characteristics in a specific PDCCH monitoring period and are synchronized in time. In case of overlap, the terminal can select a specific control resource set according to the QCL priority determination operation and monitor control resource sets that have the same QCL-TypeD characteristics as the corresponding control resource set. That is, when multiple control resource sets overlap in time, only one QCL-TypeD characteristic can be received. At this time, the criteria for determining QCL priority may be as follows.

- Standard 1. Control resource set connected to the common search section of the lowest index within the cell corresponding to the lowest index among cells containing the common search section.

- Standard 2. Control resource set connected to the terminal-specific search section of the lowest index within the cell corresponding to the lowest index among cells containing the terminal-specific search section.

As described above, if each of the above standards is not met, the following standards apply. For example, if control resource sets overlap in time in a specific PDCCH monitoring section, if all control resource sets are not connected to a common search section but to a terminal-specific search section, that is, if criterion 1 is not met, the terminal You can omit application of standard 1 and apply standard 2.

When selecting a control resource set based on the above-mentioned criteria, the terminal may additionally consider the following two matters regarding the QCL information set in the control resource set. First, if control resource set 1 has CSI-RS 1 as a reference signal with a QCL-TypeD relationship, and the reference signal that this CSI-RS 1 has a QCL-TypeD relationship with is SSB 1, and another If the reference signal with which control resource set 2 has a QCL-TypeD relationship is SSB 1, the terminal can consider these two control resource sets 1 and 2 as having different QCL-TypeD characteristics. Second, if control resource set 1 has CSI-RS 1 set in cell 1 as a reference signal with a relationship of QCL-TypeD, and this CSI-RS 1 is a reference signal with a relationship of QCL-TypeD SSB is 1, and control resource set 2 has CSI-RS 2 set in cell 2 as a reference signal with a QCL-TypeD relationship, and the reference signal that this CSI-RS 2 has a QCL-TypeD relationship is the same. In case of SSB 1, the terminal can consider that the two control resource sets have the same QCL-TypeD characteristics.

FIG. 12 is a diagram illustrating a method for a terminal to select a set of control resources that can be received in consideration of priority when receiving a downlink control channel in a wireless communication system according to an embodiment of the present disclosure. For example, the terminal may be configured to receive a plurality of control resource sets that overlap in time in a specific PDCCH monitoring period (1210), and these plurality of control resource sets may be a common search space or a terminal-specific search space for a plurality of cells. It may be connected to . Within the corresponding PDCCH monitoring section, there may be a control resource set 1 (1215) connected to the common search section 1 within the 1st bandwidth portion 1200 of the 1st cell, and a 1st bandwidth portion 1205 of the 2nd cell. ), there may be a No. 1 control resource set (1220) connected to the No. 1 common search section and a No. 2 control resource set (1225) connected to the No. 2 terminal-specific search section. Control resource sets (1215) and (1220) have a relationship between the No. 1 CSI-RS resource and QCL-TypeD set within the No. 1 bandwidth portion of Cell No. 1, and the control resource set (1225) is the No. 1 bandwidth of Cell No. 2. It may have a relationship between the number 1 CSI-RS resource set within the part and QCL-TypeD. Therefore, if criterion 1 is applied to the corresponding PDCCH monitoring section 1210, all other control resource sets having the same QCL-TypeD reference signal as the 1st control resource set 1215 can be received. Therefore, the terminal can receive control resource sets (1215) and (1220) in the corresponding PDCCH monitoring section (1210). As another example, the terminal may be configured to receive a plurality of control resource sets that overlap in time in a specific PDCCH monitoring period (1240), and these multiple control resource sets may be used in a common search space or a terminal-specific search space for a plurality of cells. It may be connected to the search space. Within the corresponding PDCCH monitoring section, within the 1st bandwidth portion (1230) of the 1st cell, the 1st control resource set (1245) connected to the UE-specific search section and the 2nd control resource set connected to the 2nd terminal-specific search section. (1250) may exist, and within the first bandwidth portion (1235) of the second cell, the first control resource set (1255) connected to the terminal-specific search section (1255) and the second control resource connected to the terminal-3 specific search section There may be a set (1260). Control resource sets (1245) and (1250) have a relationship between the No. 1 CSI-RS resource and QCL-TypeD set within the No. 1 bandwidth portion of Cell No. 1, and the control resource set (1255) is the No. 1 bandwidth of Cell No. 2. It has a relationship of QCL-TypeD with the No. 1 CSI-RS resource set within the part, and the control resource set 1260 can have a relationship of QCL-TypeD with the No. 2 CSI-RS resource set within the No. 1 bandwidth part of the No. 2 cell. there is. However, if standard 1 is applied to the corresponding PDCCH monitoring section 1240, there is no common search section, so the next standard, standard 2, can be applied. If standard 2 is applied to the corresponding PDCCH monitoring section 1240, all other control resource sets having the same QCL-TypeD reference signal as the control resource set 1245 can be received. Therefore, the terminal can receive control resource sets (1245) and (1250) in the corresponding PDCCH monitoring section (1240).

[Rate matching/Puncturing]

In the following, rate matching operation and puncturing operation will be described in detail.

When the time and frequency resource A for transmitting a random symbol sequence A overlaps with a random time and frequency resource B, rate matching or puncturing by transmission/reception operation of channel A considering resource C of the area where resource A and resource B overlap. motion can be considered. Specific operations can follow the details below.

Rate Matching Operation

- The base station can map and transmit channel A only for the remaining resource areas excluding resource C corresponding to the area overlapping with resource B among all resources A for which symbol sequence A is to be transmitted to the terminal. For example, symbol sequence A consists of {Symbol #1, Symbol #2, Symbol #3, Symbol 4}, and resource A is {Resource #1, Resource #2, Resource #3, Resource #4}, and resource A is {Resource #1, Resource #2, Resource #3, Resource #4}. If B is {Resource #3, Resource #5}, the base station uses symbol sequences in the remaining resources {Resource #1, Resource #2, Resource #4}, excluding {Resource #3}, which corresponds to Resource C, among resources A. A can be mapped sequentially and sent. As a result, the base station can map and transmit the symbol sequence {Symbol #1, Symbol #2, Symbol #3} to {Resource #1, Resource #2, Resource #4}, respectively.

The terminal can determine resource A and resource B from scheduling information about symbol sequence A from the base station, and through this, can determine resource C, which is an area where resource A and resource B overlap. The terminal can receive symbol sequence A assuming that symbol sequence A has been mapped and transmitted in the remaining areas excluding resource C among all resources A. For example, symbol sequence A consists of {Symbol #1, Symbol #2, Symbol #3, Symbol 4}, and resource A is {Resource #1, Resource #2, Resource #3, Resource #4}, and resource A is {Resource #1, Resource #2, Resource #3, Resource #4}. If B is {resource #3, resource #5}, the terminal has a symbol sequence in the remaining resources {resource #1, resource #2, resource #4}, excluding {resource #3} corresponding to resource C among resources A. A can be received assuming that it is mapped sequentially. As a result, the terminal assumes that the symbol sequence {Symbol #1, Symbol #2, Symbol #3} has been mapped and transmitted to {Resource #1, Resource #2, Resource #4}, respectively, and performs a series of subsequent reception operations. You can.

Puncturing operation

If there is a resource C corresponding to an area overlapping with resource B among all resources A that want to transmit symbol sequence A to the terminal, the base station maps symbol sequence A to the entire resource A, but transmits in the resource area corresponding to resource C. Without performing transmission, transmission can be performed only for the remaining resource areas excluding resource C among resource A. For example, symbol sequence A consists of {Symbol #1, Symbol #2, Symbol #3, Symbol 4}, and resource A is {Resource #1, Resource #2, Resource #3, Resource #4}, and resource A is {Resource #1, Resource #2, Resource #3, Resource #4}. If B is {resource #3, resource #5}, the base station sends the symbol sequence A {symbol #1, symbol #2, symbol #3, symbol #4} to resource A {resource #1, resource #2, resource # 3, Resource #4}, respectively, and symbol sequences corresponding to {Resource #1, Resource #2, Resource #4}, which are the remaining resources except {Resource #3}, which corresponds to Resource C among Resource A. { Only symbol #1, symbol #2, and symbol #4} can be transmitted, and {symbol #3} mapped to {resource #3} corresponding to resource C may not be transmitted. As a result, the base station can map and transmit the symbol sequence {Symbol #1, Symbol #2, Symbol #4} to {Resource #1, Resource #2, Resource #4}, respectively.

The terminal can determine resource A and resource B from scheduling information about symbol sequence A from the base station, and through this, can determine resource C, which is an area where resource A and resource B overlap. The terminal can receive symbol sequence A assuming that symbol sequence A is mapped to the entire resource A and transmitted only in the remaining areas excluding resource C among resource area A. For example, symbol sequence A consists of {Symbol #1, Symbol #2, Symbol #3, Symbol 4}, and resource A is {Resource #1, Resource #2, Resource #3, Resource #4}, and resource A is {Resource #1, Resource #2, Resource #3, Resource #4}. If B is {resource #3, resource #5}, the terminal has the symbol sequence A {symbol #1, symbol #2, symbol #3, symbol #4} as resource A {resource #1, resource #2, resource # 3 and Resource #4}, respectively, but it can be assumed that {Symbol #3} mapped to {Resource #3} corresponding to resource C is not transmitted, and {Resource #3} corresponding to resource C among resources A } can be received assuming that the symbol sequences {Symbol #1, Symbol #2, Symbol #4} corresponding to the remaining resources {Resource #1, Resource #2, Resource #4} have been mapped and transmitted. As a result, the terminal assumes that the symbol sequence {Symbol #1, Symbol #2, Symbol #4} has been mapped and transmitted to {Resource #1, Resource #2, Resource #4}, respectively, and performs a series of subsequent reception operations. You can.

In the following, a method for setting up rate matching resources for the purpose of rate matching in the 5G communication system will be described. Rate matching means that the size of the signal is adjusted considering the amount of resources that can transmit the signal. For example, rate matching of a data channel may mean that the data channel is not mapped and transmitted for a specific time and frequency resource area, and the size of the data is adjusted accordingly.

FIG. 11 is a diagram illustrating a method for a base station and a terminal to transmit and receive data in consideration of a downlink data channel and rate matching resources.

Figure 11 shows a downlink data channel (PDSCH, 1101) and a rate matching resource (1102). The base station may configure one or multiple rate matching resources 1102 to the terminal through higher layer signaling (eg, RRC signaling). Rate matching resource 1102 setting information may include time axis resource allocation information 1103, frequency axis resource allocation information 1104, and period information 1105. In the following, the bitmap corresponding to the frequency axis resource allocation information 1104 is referred to as the “first bitmap,” the bitmap corresponding to the time axis resource allocation information 1103 is referred to as the “second bitmap,” and the bitmap corresponding to the period information 1105. Name the bitmap as “third bitmap”. If all or part of the time and frequency resources of the scheduled data channel 1101 overlap with the set rate matching resource 602, the base station may rate match and transmit the data channel 1101 in the rate matching resource 1102 portion. , the terminal can perform reception and decoding after assuming that the data channel 1101 is rate matched in the rate matching resource 1102 portion.

Through additional settings, the base station can dynamically notify the terminal through DCI whether to rate match the data channel in the set rate matching resource portion (corresponding to the "rate matching indicator" in the above-mentioned DCI format). . Specifically, the base station can select some of the set rate matching resources and group them into a rate matching resource group, and inform the terminal of the rate matching of the data channel for each rate matching resource group through DCI using a bitmap method. You can instruct. For example, if four rate matching resources, RMR#1, RMR#2, RMR#3, and RMR#4 are set, the base station sets RMG#1={RMR#1, RMR#2}, RMG# as a rate matching group. 2={RMR#3, RMR#4} can be set, and 2 bits in the DCI field can be used to indicate to the terminal whether rate matching is performed in RMG#1 and RMG#2, respectively, using a bitmap. For example, if rate matching is to be performed, “1” can be indicated, and if rate matching should not be done, “0” can be indicated.

In 5G, the granularity of “RB symbol level” and “RE level” is supported by configuring the above-described rate matching resources in the terminal. More specifically, the following setting method can be followed.

RB symbol level

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

- As a reserved resource within the bandwidth portion, a resource in which the time and frequency resource areas of the corresponding reserved resource are set by combining an RB level bitmap and a symbol level bitmap on the frequency axis may be included. The spare resource may span one or two slots. A time domain pattern (periodicityAndPattern) in which time and frequency domains composed of each RB level and symbol level bitmap pair are repeated may be additionally set.

- A time and frequency domain resource area set as a control resource set within the bandwidth portion and a resource area corresponding to a time domain pattern set as a search space setting in which the resource area is repeated may be included.

RE level

The terminal can receive the following settings through upper layer signaling.

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

- It may include configuration information about a resource set corresponding to one or multiple ZP (Zero Power) CSI-RSs within the bandwidth portion.

[LTE CRS rate match related]

Next, the rate match process for the above-described LTE CRS will be described in detail. For the coexistence of LTE (Long Term Evolution) and NR (New RAT) (LTE-NR Coexistence), NR provides the NR terminal with a function to set the pattern of LTE's CRS (Cell Specific Reference Signal). More specifically, the CRS pattern may be provided by RRC signaling including at least one parameter in the ServingCellConfig Information Element (IE) or ServingCellConfigCommon IE. Examples of the above parameters may include lte-CRS-ToMatchAround, lte-CRS-PatternList1-r16, lte-CRS-PatternList2-r16, crs-RateMatch-PerCORESETPoolIndex-r16, etc.

Rel-15 NR provides a function where one CRS pattern can be set per serving cell through the lte-CRS-ToMatchAround parameter. In Rel-16 NR, the above function has been expanded to enable setting of multiple CRS patterns per serving cell. More specifically, in a single-TRP (transmission and reception point) configured terminal, one CRS pattern can be configured per LTE carrier, and in a multi-TRP configured terminal, two CRS patterns can be configured per LTE carrier. can now be set. For example, in a Single-TRP configuration terminal, up to three CRS patterns can be configured per serving cell through the lte-CRS-PatternList1-r16 parameter. As another example, in a multi-TRP configured terminal, CRS may be configured for each TRP. That is, the CRS pattern for TRP1 can be set through the lte-CRS-PatternList1-r16 parameter, and the CRS pattern for TRP2 can be set through the lte-CRS-PatternList2-r16 parameter. Meanwhile, when two TRPs are set as above, whether the CRS patterns of both TRP1 and TRP2 are applied to a specific PDSCH (Physical Downlink Shared Channel), or only the CRS pattern for one TRP is applied, crs-RateMatch-PerCORESETPoolIndex It is determined through the -r16 parameter. If the crs-RateMatch-PerCORESETPoolIndex-r16 parameter is set to enabled, only the CRS pattern of one TRP is applied, and in other cases, the CRS patterns of both TRPs are applied.

Table 17 shows ServingCellConfig IE including the CRS pattern, and Table 18 shows RateMatchPatternLTE-CRS IE including at least one parameter for the CRS pattern.

[Table 17]

[Table 18]

[PDSCH: Frequency resource allocation related]

FIG. 13 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 an embodiment of the present disclosure.

Figure 13 shows three frequency axis resource allocation methods: type 0 (13-00), type 1 (13-05), and dynamic switch (13-10) that can be set through the upper layer in the NR wireless communication system. This is a drawing showing them.

Referring to FIG. 13, if the terminal is set to use only resource type 0 through higher layer signaling (13-00), some downlink control information (DCI) that allocates a PDSCH to the corresponding terminal is NRBG number. Contains a bitmap composed of bits. The conditions for this will be explained later. At this time, NRBG refers to the number of RBG (resource block group) determined as shown in [Table 19] according to the BWP size assigned by the BWP indicator and the upper layer parameter rbg-Size, and is determined by the bitmap. Data is transmitted to the RBG indicated as 1.

[Table 19]

If the terminal is set to use only resource type 1 through upper layer signaling (13-05), some DCIs that allocate PDSCH to the terminal are 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 (13-20) and the length (13-25) of the frequency axis resources continuously allocated from it.

If the terminal is set to use both resource type 0 and resource type 1 through upper layer signaling (13-10), some DCIs that allocate PDSCH to the corresponding terminal have payload (13-15) to set resource type 0. and payload (13-20, 13-25) for setting resource type 1, and includes frequency axis resource allocation information consisting of bits of the larger value (13-35). 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 indicates that resource type 0 is used, and if the value of '1' is '1', the resource It may be indicated that type 1 is used.

[PDSCH/PUSCH: Time resource allocation related]

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

The base station provides the terminal with a table of time domain resource allocation information for the downlink data channel (Physical Downlink Shared Channel, PDSCH) and uplink data channel (Physical Uplink Shared Channel, PUSCH), and higher layer signaling (e.g. For example, it can be set to RRC signaling). For PDSCH, a table consisting of up to maxNrofDL-Allocations=16 entries can be set, and for PUSCH, a table consisting of up to maxNrofUL-Allocations=16 entries can be set up. In one embodiment, the time domain resource allocation information includes the PDCCH-to-PDSCH slot timing (corresponding to the time interval in slot units between the time when the PDCCH is received and the time when the PDSCH scheduled by the received PDCCH is transmitted, denoted as K0) ), PDCCH-to-PUSCH slot timing (corresponds to the time interval in slot units between the time when PDCCH is received and the time when PUSCH scheduled by the received PDCCH is transmitted, denoted as K2), PDSCH or PUSCH within the slot Information on the location and length of the scheduled start symbol, mapping type of PDSCH or PUSCH, etc. may be included. For example, information such as [Table 20] or [Table 21] below may be transmitted from the base station to the terminal.

[Table 20]

[Table 21]

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

FIG. 14 is a diagram illustrating an example of PDSCH time axis resource allocation in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 14, the base station uses the subcarrier spacing (SCS) ( μ _PDSCH , μ _PDCCH ) and scheduling offset of the data channel and control channel set using the upper layer. The time axis position of the PDSCH resource can be indicated according to the offset (K0) value and the OFDM symbol start position (14-00) and length (14-05) within one slot that are dynamically indicated through DCI.

FIG. 15 is a diagram illustrating an example of time axis resource allocation according to subcarrier intervals of a data channel and a control channel in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 15, when the subcarrier spacing of the data channel and the control channel is the same (15-00, μ _PDSCH = μ _PDCCH ), the slot numbers for data and control are the same, so the base station and the terminal A scheduling offset can be created according to the designated slot offset K0. On the other hand, when the subcarrier spacing of the data channel and the control channel are different (15-05, μ _PDSCH ≠ μ _PDCCH ), the slot numbers for data and control are different, so the base station and the terminal use the subcarrier spacing of the PDCCH Based on , a scheduling offset can be created according to a predetermined slot offset K0.

[PDSCH: TCI state activation MAC-CE]

Next, we will look at the beam setting method for PDSCH. Figure 16 shows the process for beam setting and activation of PDSCH. The list of TCI states for PDSCH can be indicated through a higher layer list such as RRC (16-00). The list of TCI states may be indicated, for example, as tci-StatesToAddModList and/or tci-StatesToReleaseList in the PDSCH-Config IE for each BWP. Next, some of the list of TCI states can be activated through MAC-CE (16-20). The maximum number of activated TCI states can be determined depending on the capabilities reported by the terminal. Figure 17 shows an example of the MAC-CE structure (17-00) for PDSCH TCI state activation/deactivation.

The meaning of each field in the MAC CE and the values that can be set for each field are as follows.

[PUSCH: Transmission method related]

Next, the scheduling method of PUSCH transmission will be described. PUSCH transmission can be dynamically scheduled by the UL grant in DCI or operated by configured grant Type 1 or Type 2. Dynamic scheduling instructions for PUSCH transmission are possible in DCI format 0_0 or 0_1.

Configured grant Type 1 PUSCH transmission can be set semi-statically through reception of configuredGrantConfig including rrc-ConfiguredUplinkGrant of [Table 22] through higher-order signaling without receiving the UL grant in DCI. Configured grant Type 2 PUSCH transmission can be scheduled semi-persistently by the UL grant in DCI after receiving configuredGrantConfig that does not include rrc-ConfiguredUplinkGrant of [Table 22] through higher-level signaling. When PUSCH transmission operates by a configured grant, the parameters applied to PUSCH transmission are [ It is applied through configuredGrantConfig, the higher-level signaling in Table 22]. If the terminal is provided with transformPrecoder in configuredGrantConfig, which is the higher-order signaling in [Table 22], the terminal applies tp-pi2BPSK in pusch-Config in [Table 23] to PUSCH transmission operated by the configured grant.

[Table 22]

Next, the PUSCH transmission method will be 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 transmission method and a non-codebook-based transmission method, respectively, depending on whether the value of txConfig in pusch-Config of [Table 23], which is the upper signaling, is 'codebook' or 'nonCodebook'.

As described above, PUSCH transmission can be scheduled dynamically through DCI format 0_0 or 0_1, and can be set semi-statically by a configured grant. If the UE is instructed to schedule PUSCH transmission through DCI format 0_0, the UE transmits PUSCH using the pucch-spatialRelationInfoID corresponding to the UE-specific PUCCH resource corresponding to the minimum ID within the activated uplink BWP within the serving cell. Beam setup for transmission is performed, and at this time, PUSCH transmission is based on a single antenna port. The terminal does not expect scheduling for PUSCH transmission through DCI format 0_0 within a BWP in which a PUCCH resource including pucch-spatialRelationInfo is not set. If the terminal has not set txConfig in pusch-Config in [Table 23], the terminal does not expect to be scheduled in DCI format 0_1.

[Table 23]

Next, codebook-based PUSCH transmission is explained. Codebook-based PUSCH transmission can be dynamically scheduled through DCI format 0_0 or 0_1 and can operate semi-statically by configured grant. When the codebook-based PUSCH is scheduled dynamically by DCI format 0_1 or set semi-statically by a configured grant, the terminal uses SRS Resource Indicator (SRI), Transmission Precoding Matrix Indicator (TPMI), and transmission rank (of the PUSCH transmission layer). Based on the number, the precoder for PUSCH transmission is determined.

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

The precoder to be used for PUSCH transmission is selected from the uplink codebook with the number of antenna ports equal to the nrofSRS-Ports value in SRS-Config, which is upper signaling. In codebook-based PUSCH transmission, the UE determines the codebook subset based on TPMI and codebookSubset in pusch-Config, which is higher-level signaling. The codebookSubset in pusch-Config, which is the upper signaling, 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 reports 'partialAndNonCoherent' as a UE capability, the UE does not expect the value of codebookSubset, which is higher level signaling, to be set to 'fullyAndPartialAndNonCoherent'. Additionally, if the UE reports 'nonCoherent' as a UE capability, the UE does not expect the value of codebookSubset, which is higher-order signaling, to be set to 'fullyAndPartialAndNonCoherent' or 'partialAndNonCoherent'. If nrofSRS-Ports in SRS-ResourceSet, which is upper signaling, indicates two SRS antenna ports, the terminal does not expect the value of codebookSubset, which is upper signaling, to be set to 'partialAndNonCoherent'.

The terminal can receive one SRS resource set whose usage value in the upper-level signaling SRS-ResourceSet is set to 'codebook', and one SRS resource within the corresponding SRS resource set can be indicated through SRI. If multiple SRS resources are set in an SRS resource set where the usage value in the upper signaling SRS-ResourceSet is set to 'codebook', the terminal sets the value of nrofSRS-Ports in the higher signaling SRS-Resource to the same value for all SRS resources. I look forward to seeing this set up.

The terminal transmits one or more SRS resources included in the SRS resource set with the usage value set to 'codebook' to the base station according to higher-level signaling, and the base station selects one of the SRS resources transmitted by the terminal and sends the corresponding SRS Instructs the terminal to perform PUSCH transmission using the transmission beam information of the resource. At this time, in codebook-based PUSCH transmission, SRI is used as information to select the index of one SRS resource and is included in DCI. Additionally, the base station includes information indicating the TPMI and rank that the terminal will use for PUSCH transmission in the DCI. The terminal uses the SRS resource indicated by the SRI and performs PUSCH transmission by applying the rank indicated based on the transmission beam of the SRS resource and the precoder indicated by TPMI.

Next, non-codebook-based PUSCH transmission is explained. Non-codebook-based PUSCH transmission can be dynamically scheduled through DCI format 0_0 or 0_1 and can operate semi-statically by configured grant. If at least one SRS resource is set in the SRS resource set where the usage value in the higher-level signaling SRS-ResourceSet is set to 'nonCodebook', the terminal can receive non-codebook-based PUSCH transmission scheduled through DCI format 0_1.

For an SRS resource set in which the usage value in the upper signaling SRS-ResourceSet is set to 'nonCodebook', the terminal can receive one connected NZP CSI-RS resource (non-zero power CSI-RS). The terminal can perform calculations on the precoder for SRS transmission through measurement of 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 from the terminal is less than 42 symbols, the terminal updates information about the precoder for SRS transmission. don't expect it to happen

If the value of resourceType in the upper signaling SRS-ResourceSet is set to 'aperiodic', the connected NZP CSI-RS is indicated by SRS request, a 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, a connected NZP CSI-RS exists if the value of the field SRS request in DCI format 0_1 or 1_1 is not '00'. It indicates that At this time, the relevant DCI must not indicate cross carrier or cross BWP scheduling. Additionally, if the value of the SRS request indicates the existence of NZP CSI-RS, the NZP CSI-RS is located in the slot in which the PDCCH including the SRS request field was transmitted. At this time, the TCI states set in the scheduled subcarrier are not set to QCL-TypeD.

If a periodic or semi-persistent SRS resource set is set, the connected NZP CSI-RS can be indicated through the associatedCSI-RS in the SRS-ResourceSet, which is the higher level signaling. For non-codebook-based transmission, the terminal does not expect that spatialRelationInfo, the upper-level signaling for the SRS resource, and associatedCSI-RS in the upper-level signaling SRS-ResourceSet are set together.

When a terminal receives a plurality of SRS resources, it 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, SRI can be indicated through a field SRS resource indicator in DCI or set through srs-ResourceIndicator, which is higher-level signaling. Similar to the codebook-based PUSCH transmission described above, when the terminal receives an SRI through DCI, the SRS resource indicated by the SRI is an SRS resource corresponding to the SRI among the SRS resourcs transmitted before the PDCCH containing the SRI. it means. The terminal can use one or multiple 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 terminal to the base station. It is decided. At this time, SRS resources simultaneously transmitted by the terminal occupy the same RB. The terminal sets one SRS port for each SRS resource. Only one SRS resource set with the usage value in the upper-level signaling SRS-ResourceSet set to 'nonCodebook' can be set, and up to four SRS resources for non-codebook-based PUSCH transmission can be set.

The base station transmits one NZP-CSI-RS connected to the SRS resource set to the terminal, and the terminal transmits one or more SRS resources in the corresponding SRS resource set based on the results measured when receiving the corresponding NZP-CSI-RS. Calculate the precoder to use when transmitting. The terminal applies the calculated precoder when transmitting one or more SRS resources in the SRS resource set whose usage is set to 'nonCodebook' to the base station, and the base station transmits one or more SRS resources among the one or more SRS resources received. Select SRS resource. At this time, in non-codebook-based PUSCH transmission, SRI represents an index that can express a combination of one or multiple SRS resources, and the SRI is included in 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.

[Related to reporting terminal capabilities]

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

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

In the above step, the terminal that has received a UE capability report request from the base station configures the terminal capability according to the RAT type and band information requested from the base station. Below is a summary of how the terminal configures UE capabilities in the NR system.

One. If the terminal receives a list of LTE and/or NR bands through a UE capability request from the base station, the terminal configures a band combination (BC) for EN-DC and NR stand alone (SA). In other words, a BC candidate list for EN-DC and NR SA is constructed based on the bands requested from the base station through FreqBandList. Additionally, the bands are prioritized in the order listed in FreqBandList.

2. If the base station requests UE capability reporting by setting the “eutra-nr-only” flag or “eutra” flag, the UE completely removes NR SA BCs from the candidate list of configured BCs. This operation can only occur if the LTE base station (eNB) requests “eutra” capability.

3. Afterwards, the terminal removes fallback BCs from the candidate list of BCs configured in the above step. Here, fallback BC means BC that can be obtained by removing the band corresponding to at least one SCell from any BC, because the BC before removing the band corresponding to at least one SCell can already cover the fallback BC. It can be omitted. This step also applies to MR-DC, i.e. LTE bands as well. The BCs remaining after this step are the final “candidate BC list”.

4. The terminal selects BCs to report by selecting BCs that fit the requested RAT type from the final “candidate BC list” above. In this step, the terminal configures the supportedBandCombinationList in a given order. In other words, the terminal configures the BC and UE capabilities to be reported in accordance with the order of the preset rat-Type. (nr -> eutra-nr -> eutra). Additionally, a featureSetCombination is constructed for the configured supportedBandCombinationList, and a list of "candidate feature set combinations" is constructed from the candidate BC list from which the list of fallback BCs (containing capabilities of the same or lower level) is removed. The above “candidate feature set combination” includes both feature set combinations for NR and EUTRA-NR BC, and can be obtained from the feature set combination of the UE-NR-Capabilities and UE-MRDC-Capabilities containers.

5. Additionally, if the requested rat Type is eutra-nr and it affects, featureSetCombinations are included in both containers: UE-MRDC-Capabilities and UE-NR-Capabilities. However, NR's feature set includes only UE-NR-Capabilities.

After the terminal capability is configured, the terminal transmits a terminal capability information message containing the terminal capability to the base station. The base station then performs appropriate scheduling and transmission/reception management for the terminal based on the terminal capabilities received from the terminal.

[CA/DC related]

FIG. 18 is a diagram illustrating the wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation, and dual connectivity situation according to an embodiment of the present disclosure.

Referring to Figure 18, the wireless protocols of the next-generation mobile communication system are NR SDAP (Service Data Adaptation Protocol S25, S70), NR PDCP (Packet Data Convergence Protocol S30, S65), and NR RLC (Radio Link Control) at the terminal and NR base station, respectively. S35, S60) and NR MAC (Medium Access Control S40, S55).

The main functions of NR SDAP (S25, S70) may include some of the following functions:

- Transfer of user plane data

- Mapping function of QoS flow and data bearer for uplink and downlink (mapping between a QoS flow and a DRB for both DL and UL)

- Marking QoS flow ID in both DL and UL packets for uplink and downlink

- A function to map reflective QoS flow to data bearer for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

For the SDAP layer device, the terminal can receive an RRC message to configure whether to use the header of the SDAP layer device or the function of the SDAP layer device for each PDCP layer device, each bearer, or each logical channel, and the SDAP header When set, the terminal sends uplink and downlink QoS flows and mapping information to the data bearer to the NAS QoS reflection setting 1-bit indicator (NAS reflective QoS) and the AS QoS reflection setting 1-bit indicator (AS reflective QoS) in the SDAP header. You can instruct to update or reset. The SDAP header may include QoS flow ID information indicating QoS. The QoS information can be used as data processing priority, scheduling information, etc. to support smooth service.

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

- Header compression and decompression (ROHC only)

- Transfer of user data

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- Order reordering function (PDCP PDU reordering for reception)

- Duplicate detection of lower layer SDUs

- Retransmission of PDCP SDUs

- Ciphering and deciphering

- Timer-based SDU discard in uplink.

In the above, the reordering function of the NR PDCP device refers to the function of rearranging the PDCP PDUs received from the lower layer in order based on the PDCP SN (sequence number), and delivering data to the upper layer in the reordered order. may include. Alternatively, the reordering function of the NR PDCP device may include a function of directly forwarding without considering the order, may include a function of reordering the lost PDCP PDUs, and may include a function of recording the lost PDCP PDUs. It may include a function to report the status of PDUs to the transmitting side, and may include a function to request retransmission of lost PDCP PDUs.

The main functions of NR RLC (S35, S60) may include some of the following functions.

- Data transfer function (Transfer of upper layer PDUs)

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- ARQ function (Error Correction through ARQ)

- Concatenation, segmentation and reassembly of RLC SDUs

- Re-segmentation of RLC data PDUs

- Reordering of RLC data PDUs

- Duplicate detection

- Protocol error detection

- RLC SDU delete function (RLC SDU discard)

- RLC re-establishment function

In the above, the in-sequence delivery function of the NR RLC device refers to the function of delivering RLC SDUs received from the lower layer to the upper layer in order. The in-sequence delivery function of the NR RLC device may include the function of reassembling and delivering when one RLC SDU is originally received by being divided into several RLC SDUs, and the received RLC PDUs It may include a function for reordering based on RLC SN (sequence number) or PDCP SN (sequence number), and may include a function for reordering and recording lost RLC PDUs. It may include a function to report status to the transmitting side, and may include a function to request retransmission of lost RLC PDUs. The in-sequence delivery function of the NR RLC device may include a function of delivering only the RLC SDUs up to the lost RLC SDU in order when there is a lost RLC SDU, or the lost RLC SDU may be transmitted to the upper layer in order. Even if there are RLC SDUs, if a predetermined timer has expired, a function may be included to deliver all RLC SDUs received before the timer starts to the upper layer in order. Alternatively, the in-sequence delivery function of the NR RLC device may include a function of delivering all RLC SDUs received to date to the upper layer in order if a predetermined timer expires even if there are lost RLC SDUs. In addition, the RLC PDUs described above can be processed in the order they are received (in the order of arrival, regardless of the order of the serial number or sequence number) and delivered to the PDCP device out of sequence (out-of sequence delivery). In the case of a segment, It is possible to receive segments stored in a buffer or to be received later, reconstruct them into one complete RLC PDU, process them, and transmit them 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 the multiplexing function of the NR MAC layer.

In the above, the out-of-sequence delivery function of the NR RLC device refers to the function of directly delivering RLC SDUs received from a lower layer to the upper layer regardless of the order, and originally, one RLC SDU is transmitted to multiple RLCs. If it is received divided into SDUs, it may include a function to reassemble and transmit them, and it may include a function to store the RLC SN or PDCP SN of the received RLC PDUs, sort the order, and record lost RLC PDUs. You can.

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

- Mapping function (Mapping between logical channels and transport channels)

- Multiplexing/demultiplexing of MAC SDUs

- Scheduling information reporting

- HARQ function (Error correction through HARQ)

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification

- Transport format selection function

- Padding function

The NR PHY layer (S45, S50) performs the operation of channel coding and modulating upper layer data, converting it into an OFDM symbol and transmitting it over a wireless channel, or demodulating and channel decoding the OFDM symbol received through a wireless channel and transmitting it to the upper layer. It can be done.

The detailed structure of the wireless protocol structure may vary depending on the carrier (or cell) operation method. For example, when the base station transmits data to the terminal based on a single carrier (or cell), the base station and the terminal use a protocol structure with a single structure for each layer, such as S00. On the other hand, when the base station transmits data to the terminal based on CA (carrier aggregation) using multiple carriers in a single TRP, the base station and the terminal have a single structure up to RLC like S10, but a protocol that multiplexes the PHY layer through the MAC layer. structure is used. As another example, when the base station transmits data to the terminal based on DC (dual connectivity) using multiple carriers in multiple TRPs, the base station and the terminal have a single structure up to RLC like S20, but transmit data to the PHY layer through the MAC layer. A multiplexing protocol structure is used.

Referring to the descriptions related to PDCCH and beam settings described above, repetitive PDCCH transmission is not currently supported in Rel-15 and Rel-16 NR, making it difficult to achieve the required reliability in scenarios that require high reliability, such as URLLC. The present invention provides a PDCCH repetitive transmission method through multiple transmission points (TRP) to improve PDCCH reception reliability of the terminal. Specific methods are described in detail in the examples below.

Hereinafter, embodiments of the present disclosure will be described in detail with the accompanying drawings. The content in this disclosure is applicable to FDD and TDD systems. Hereinafter, in the present disclosure, higher signaling (or higher layer signaling) is a signal transmission method in which a signal is transmitted from a base station to a terminal using a downlink data channel of the physical layer, or from a terminal to a base station using an uplink data channel of the physical layer, It may also be referred to as RRC signaling, PDCP signaling, or MAC (medium access control) control element (MAC CE).

Hereinafter, in this disclosure, when determining whether to apply cooperative communication, the terminal determines whether the PDCCH(s) allocating the PDSCH to which cooperative communication is applied has a specific format, or the PDCCH(s) allocating the PDSCH to which cooperative communication is applied is cooperative. It contains a specific indicator indicating whether communication is applied, or the PDCCH(s) allocating the PDSCH to which cooperative communication is applied is scrambled with a specific RNTI, or assumes application of cooperative communication in a specific section indicated by the upper layer, etc. It is possible to use a variety of methods. For convenience of explanation, the case where the UE receives a PDSCH to which cooperative communication is applied based on conditions similar to the above will be referred to as the NC-JT case.

Hereinafter, in the present disclosure, determining the priority between A and B means selecting the one with the higher priority and performing the corresponding operation according to a predetermined priority rule, or selecting the one with the lower priority. It can be mentioned in various ways, such as omit or drop the action.

Hereinafter, in the present disclosure, the above examples are described through a number of embodiments, but these are not independent examples, and it is possible for one or more embodiments to be applied simultaneously or in combination.

[NC-JT related]

According to an embodiment of the present disclosure, non-coherent joint transmission (NC-JT) may be used for the UE to receive a PDSCH from multiple TRPs.

Unlike existing systems, the 5G wireless communication system can support not only services that require high transmission speeds, but also services that require very short transmission delays and services that require high connection density. In a wireless communication network including multiple cells, transmission and reception points (TRPs), or beams, coordinated transmission between each cell, TRP, or/and beam increases the strength of the signal received by the terminal or increases the strength of the signal received by each cell. , TRP or/and inter-beam interference control can be efficiently performed to satisfy various service requirements.

Joint Transmission (JT) is a representative transmission technology for the above-described cooperative communication, and transmits signals to one terminal through multiple different cells, TRPs, or/and beams, thereby measuring the strength or throughput of the signal received by the terminal. It is a technology that increases. At this time, the characteristics of the channel between each cell, TRP or/and beam and the terminal may be significantly different, especially those that support non-coherent precoding between each cell, TRP or/and beam. In the case of Non-Coherent Joint Transmission (NC-JT), individual precoding, MCS, resource allocation, TCI indication, etc. are required depending on the channel characteristics of each cell, TRP or/and link between beam and terminal. You can.

The above-described NC-JT transmission includes a downlink data channel (PDSCH: physical downlink shared channel), a downlink control channel (PDCCH: physical downlink control channel), an uplink data channel (PUSCH: physical uplink shared channel), and an uplink control channel. It can be applied to at least one channel (PUCCH: physical uplink control channel). When transmitting PDSCH, transmission information such as precoding, MCS, resource allocation, and TCI is indicated in DL DCI, and for NC-JT transmission, the transmission information must be indicated independently for each cell, TRP, or/and beam. This is a major factor in increasing the payload required for DL DCI transmission, which may adversely affect the reception performance of the PDCCH transmitting DCI. Therefore, to support JT of PDSCH, it is necessary to carefully design the tradeoff between DCI information amount and control information reception performance.

FIG. 19 is a diagram illustrating an example of antenna port configuration and resource allocation for transmitting a PDSCH using cooperative communication in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 19, examples for PDSCH transmission are explained for each Joint Transmission (JT) technique, and examples for allocating radio resources for each TRP are shown.

Referring to FIG. 19, an example (N000) for Coherent Joint Transmission (C-JT) supporting coherent precoding between each cell, TRP or/and beam is shown.

In the case of C-JT, TRP A (N005) and TRP B (N010) transmit single data (PDSCH) to the terminal (N015), and joint precoding can be performed in multiple TRPs. This may mean that DMRS is transmitted through the same DMRS ports so that TRP A (N005) and TRP B (N010) transmit the same PDSCH. For example, TRP A (N005) and TRP B (N010) can transmit DRMS to the terminal through DMRS port A and DMRS B, respectively. In this case, the terminal can receive one DCI information for receiving one PDSCH demodulated based on DMRS transmitted through DMRS port A and DMRS B.

Figure 19 is an example of non-coherent joint transmission (NC-JT) supporting non-coherent precoding between each cell, TRP or / and beam for PDSCH transmission (Non-Coherent Joint Transmission) N020).

In the case of NC-JT, a PDSCH is transmitted to the terminal (N035) for each cell, TRP, or/and beam, and individual precoding may be applied to each PDSCH. Each cell, TRP or/and beam can transmit different PDSCHs or different PDSCH layers to the terminal, thereby improving throughput compared to single cell, TRP or/and beam transmission. Additionally, each cell, TRP or/and beam can repeatedly transmit the same PDSCH to the UE, thereby improving reliability compared to single cell, TRP or/and beam transmission. For convenience of explanation, cells, TRPs or/and beams are hereinafter collectively referred to as TRPs.

At this time, if the frequency and time resources used by multiple TRPs for PDSCH transmission are all the same (N040), and if the frequency and time resources used by multiple TRPs do not overlap at all (N045), Various radio resource allocations may be considered, such as when some of the used frequency and time resources overlap (N050).

To support NC-JT, DCIs of various forms, structures, and relationships can be considered to simultaneously allocate multiple PDSCHs to one UE.

Figure 20 shows the configuration of downlink control information (DCI) for NC-JT, in which each TRP transmits a different PDSCH or a different PDSCH layer to the terminal in a wireless communication system according to an embodiment of the present disclosure. This is a diagram showing an example.

Referring to Figure 20, case #1 (N100) is from (N-1) additional TRPs (TRP#1 to TRP#(N-1)) in addition to the serving TRP (TRP#0) used when transmitting a single PDSCH. In a situation where other (N-1) PDSCHs are transmitted, this is an example in which control information for PDSCHs transmitted in (N-1) additional TRPs is transmitted independently from control information for PDSCHs transmitted in the serving TRP. . That is, the terminal provides control information on PDSCHs transmitted from different TRPs (TRP#0 to TRP#(N-1)) through independent DCIs (DCI#0 to DCI#(N-1)). It can be obtained. The formats between the independent DCIs may be the same or different, and the payloads between the DCIs may also be the same or different. In the above-mentioned case #1, the degree of control or allocation freedom for each PDSCH can be completely guaranteed, but when each DCI is transmitted in different TRPs, a difference in coverage for each DCI may occur and reception performance may deteriorate.

Case #2 (N105) is a different (N-1) from (N-1) additional TRPs (TRP#1 to TRP#(N-1)) in addition to the serving TRP (TRP#0) used when transmitting a single PDSCH. ) In a situation where PDSCHs are transmitted, control information (DCI) for the PDSCHs of (N-1) additional TRPs is transmitted, and each of these DCIs is dependent on the control information for the PDSCH transmitted from the serving TRP. see.

For example, in the case of DCI#0, which is the control information for the PDSCH transmitted from the serving TRP (TRP#0), it includes all information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2, but the cooperative TRP In the case of shortened DCI (hereinafter, sDCI) (sDCI#0 to sDCI#(N-2)), which is control information for PDSCHs transmitted from TRP#1 to TRP#(N-1), DCI format 1_0, It may contain only some of the information elements of DCI format 1_1 and DCI format 1_2. Therefore, in the case of sDCI, which transmits control information for PDSCHs transmitted from cooperative TRPs, the payload is smaller than normal DCI (nDCI), which transmits control information related to PDSCHs transmitted from serving TRPs, so it is compared with nDCI. Thus, it is possible to include reserved bits.

In the aforementioned case #2, the degree of control or allocation freedom for each PDSCH may be limited depending on the content of the information element included in sDCI, but since the reception performance of sDCI is superior to nDCI, differences in coverage for each DCI may occur. The probability may be lowered.

Case #3 (N110) is a different (N-1) from (N-1) additional TRPs (TRP#1 to TRP#(N-1)) in addition to the serving TRP (TRP#0) used when transmitting a single PDSCH. ) In a situation where PDSCHs are transmitted, one control information for the PDSCHs of (N-1) additional TRPs is transmitted, and this DCI is dependent on the control information for the PDSCHs transmitted from the serving TRP.

For example, in the case of DCI#0, which is the control information for the PDSCH transmitted from the serving TRP (TRP#0), it includes all information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2, and the cooperative TRP In the case of control information for PDSCHs transmitted from (TRP#1 to TRP#(N-1)), only some of the information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2 are used as one 'secondary' DCI ( It is possible to collect and transmit via sDCI). For example, the sDCI may include at least one of HARQ-related information such as frequency domain resource assignment, time domain resource assignment, and MCS of cooperative TRPs. In addition, for information not included in sDCI, such as BWP (bandwidth part) indicator or carrier indicator, the DCI (DCI#0, normal DCI, nDCI) of the serving TRP can be followed.

In case #3 (N110), the control or allocation freedom of each PDSCH may be limited depending on the content of the information element included in sDCI, but the reception performance of sDCI can be adjusted and case #1 (N100) or case #2 Compared to (N105), the complexity of DCI blind decoding of the terminal may be reduced.

Case #4 (N115) is a different (N-1) from (N-1) additional TRPs (TRP#1 to TRP#(N-1)) in addition to the serving TRP (TRP#0) used when transmitting a single PDSCH. ) In a situation where PDSCHs are transmitted, this is an example of transmitting control information for PDSCHs transmitted from (N-1) additional TRPs on the same DCI (Long DCI) as control information for PDSCHs transmitted from serving TRPs. That is, the terminal can obtain control information about PDSCHs transmitted from different TRPs (TRP#0 to TRP#(N-1)) through a single DCI. In case #4 (N115), the complexity of DCI blind decoding of the terminal may not increase, but the number of cooperative TRPs may be limited due to long DCI payload limitations, and the degree of freedom in PDSCH control or allocation may be low.

In the following description and embodiments, sDCI may refer to various secondary DCIs such as shortened DCI, secondary DCI, or normal DCI (DCI format 1_0 to 1_1 described above) including PDSCH control information transmitted in a cooperative TRP, and has no special restrictions. Unless otherwise specified, the description is similarly applicable to the various auxiliary DCIs above.

In the following description and embodiments, the cases of case #1 (N100), case #2 (N105), and case #3 (N110), in which more than one DCI (PDCCH) is used to support NC-JT, are used as multiple PDCCH. The case #4 (N115) described above, in which a single DCI (PDCCH) is used to support NC-JT, can be classified as a single PDCCH-based NC-JT. In PDSCH transmission based on Multiple PDCCH, CORESET in which the DCI of the serving TRP (TRP#0) is scheduled and CORESET in which the DCI of the cooperative TRPs (TRP#1 to TRP#(N-1)) are scheduled can be distinguished. Methods for distinguishing CORESETs include a method of distinguishing through upper layer indicators for each CORESET and a method of distinguishing through beam settings for each CORESET. Additionally, in single PDCCH-based NC-JT, a single DCI schedules a single PDSCH with multiple layers instead of scheduling multiple PDSCHs, and the multiple layers described above can be transmitted from multiple TRPs. At this time, the connection relationship between a layer and a TRP transmitting the layer may be indicated through a Transmission Configuration Indicator (TCI) indication for the layer.

In embodiments of the present disclosure, “cooperative TRP” may be replaced with various terms such as “cooperative panel” or “cooperative beam” in actual application.

In embodiments of the present disclosure, “when NC-JT is applied” means “when the terminal receives one or more PDSCHs simultaneously from one BWP” and “when the terminal receives two or more TCIs (Transmission It is possible to interpret it in various ways depending on the situation, such as "when PDSCH is received based on the Configuration Indicator indication" or "when the PDSCH received by the terminal is associated with one or more DMRS port groups." For convenience, one expression was used.

In the present invention, the wireless protocol structure for NC-JT can be used in various ways depending on the TRP deployment scenario. For example, when there is no or small backhaul delay between cooperative TRPs, a method (CA-like method) using a structure based on MAC layer multiplexing is possible, similar to S10 of Figure x4. On the other hand, when the backhaul delay between cooperative TRPs is too large to be ignored (for example, when more than 2 ms is required to exchange information such as CSI, scheduling, and HARQ-ACK between cooperative TRPs), it is similar to S20 in Figure x4. It is possible to secure robust characteristics against delay by using an independent structure for each TRP starting from the RLC layer (DC-like method).

A terminal that supports C-JT / NC-JT can receive C-JT / NC-JT related parameters or setting values from the upper layer settings and set the RRC parameters of the terminal based on this. For upper layer configuration, the UE can utilize UE capability parameters, for example, tci-StatePDSCH. Here, the UE capability parameter, for example, tci-StatePDSCH, can define TCI states for the purpose of PDSCH transmission, and the number of TCI states is 4, 8, 16, 32, 64, and 128 in FR1 and 64 and 128 in FR2. It can be set, and among the set number, up to 8 states can be set that can be indicated by 3 bits of the TCI field of DCI through a MAC CE message. The maximum value of 128 means the value indicated by maxNumberConfiguredTCIstatesPerCC in the tci-StatePDSCH parameter included in the terminal's capability signaling. In this way, a series of configuration processes from upper layer configuration to MAC CE configuration can be applied to a beamforming instruction or beamforming change instruction for at least one PDSCH in one TRP.

[Multi-DCI based Multi-TRP]

As an embodiment of the present disclosure, a multi-DCI based multi-TRP transmission method will be described. The multi-DCI based multi-TRP transmission method can set a downlink control channel for NC-JT transmission based on Multi-PDCCH.

In NC-JT based on Multiple PDCCH, when transmitting DCI for the PDSCH schedule of each TRP, there can be a separate CORESET or search space for each TRP. CORESET or search space for each TRP can be set as at least one of the following cases.

* Upper layer index setting for each CORESET: CORESET setting information set as the upper layer may include an index value, and the TRP that transmits the PDCCH in the corresponding CORESET can be distinguished by the index value for each CORESET set. That is, in a set of CORESETs with the same upper layer index value, the same TRP can be considered to transmit the PDCCH, or the PDCCH scheduling the PDSCH of the same TRP can be considered to be transmitted. The index for each CORESET described above may be named as CORESETPoolIndex, and for CORESETs for which the same CORESETPoolIndex value is set, it can be considered that the PDCCH is transmitted from the same TRP. In the case of CORESET where the CORESETPoolIndex value is not set, the default value of CORESETPoolIndex can be considered to be set, and the above-described default value may be 0.

- In the present disclosure, if the type of CORESETPoolIndex of each of the plurality of CORESETs included in the PDCCH-Config, which is upper layer signaling, exceeds one, that is, if each CORESET has a different CORESETPoolIndex, the terminal is operated by the base station in a multi- It can be considered that the DCI-based multi-TRP transmission method can be used.

- Differently, in the present disclosure, if each of a plurality of CORESETs included in the PDCCH-Config, which is upper layer signaling, has one type of CORESETPoolIndex, that is, if all CORESETs have the same CORESETPoolIndex of 0 or 1, the terminal is connected to the base station. It can be considered to be transmitted using single-TRP rather than using this multi-DCI-based multi-TRP transmission method.

* Multiple PDCCH-Config settings: Multiple PDCCH-Configs are set within one BWP, and each PDCCH-Config may include PDCCH settings for each TRP. In other words, a list of CORESETs for each TRP and/or a list of search spaces for each TRP may be configured in one PDCCH-Config, and one or more CORESETs and one or more search spaces included in one PDCCH-Config are considered to correspond to a specific TRP. can do.

* CORESET beam/beam group configuration: TRPs corresponding to the CORESET can be distinguished through the beam or beam group set for each CORESET. For example, if the same TCI state is set in multiple CORESETs, the CORESETs may be considered to be transmitted through the same TRP, or the PDCCH scheduling the PDSCH of the same TRP may be considered to be transmitted in the CORESETs.

* Search space beam/beam group configuration: A beam or beam group is configured for each search space, and through this, the TRP for each search space can be distinguished. For example, if the same beam/beam group or TCI state is set in multiple search spaces, the same TRP may be considered to transmit the PDCCH in the search space, or the PDCCH scheduling the PDSCH of the same TRP may be considered to be transmitted in the search space. there is.

By dividing the CORESET or search space by TRP as above, it is possible to classify PDSCH and HARQ-ACK information for each TRP, and through this, it is possible to create an independent HARQ-ACK codebook for each TRP and use an independent PUCCH resource.

The above settings may be independent for each cell or BWP. For example, two different CORESETPoolIndex values may be set for a PCell, while no CORESETPoolIndex value may be set for a specific SCell. In this case, while NC-JT transmission is configured in the PCell, it can be considered that NC-JT transmission is not configured in the SCell for which the CORESETPoolIndex value is not set.

The PDSCH TCI state activation/deactivation MAC-CE applicable to the multi-DCI-based multi-TRP transmission method can follow FIG. 17 above. If the terminal has not set CORESETPoolIndex for each of all CORESETs in the upper layer signaling PDCCH-Config, the terminal may ignore the CORESET Pool ID field (17-05) in the corresponding MAC-CE (17-00). If the terminal can support the multi-DCI-based multi-TRP transmission method, that is, if each CORESET in the terminal's upper layer signaling PDCCH-Config has a different CORESETPoolIndex, the terminal The TCI state in the DCI included in the PDCCH transmitted in CORESETs with a CORESETPoolIndex value equal to the value of the CORESET Pool ID field (17-05) can be activated. For example, if the value of the CORESET Pool ID field (17-05) in the corresponding MAC-CE (17-00) is 0, the TCI state in the DCI included in the PDCCH transmitted from CORESETs with CORESETPoolIndex of 0 is that of the corresponding MAC-CE. You can follow the activation information.

When the terminal is configured to use the multi-DCI-based multi-TRP transmission method from the base station, that is, when the type of CORESETPoolIndex for each of the plurality of CORESETs included in PDCCH-Config, which is upper layer signaling, exceeds one, or When each CORESET has a different CORESETPoolIndex, the UE can know that the following restrictions exist for PDSCHs scheduled from PDCCHs in each CORESET with two different CORESETPoolIndex.

One) If the PDSCH indicated from the PDCCH in each CORESET having two different CORESETPoolIndex completely or partially overlaps, the UE can apply the TCI states indicated from each PDCCH to different CDM groups. In other words, two or more TCI states may not be applied to one CDM group.

2) If the PDSCH indicated from the PDCCH in each CORESET having two different CORESETPoolIndex completely or partially overlaps, the UE determines the actual number of front loaded DMRS symbols, actual number of additional DMRS symbols, actual DMRS symbol location, and DMRS type of each PDSCH. We can expect them to be no different from each other.

3) The terminal can expect that the bandwidth indicated from the PDCCH in each CORESET with two different CORESETPoolIndexes is the same and the subcarrier spacing is also the same.

4) The terminal can expect that each PDCCH completely contains information about the scheduled PDSCH from the PDCCH in each CORESET having two different CORESETPoolIndex.

[Single-DCI-based Multi-TRP]

As an embodiment of the present disclosure, a single-DCI based multi-TRP transmission method is described. The single-DCI based multi-TRP transmission method can set up a downlink control channel for NC-JT transmission based on single-PDCCH.

In the single DCI-based multi-TRP transmission method, PDSCH transmitted by multiple TRPs can be scheduled with one DCI. At this time, the number of TCI states can be used as a method to indicate the number of TRPs transmitting the corresponding PDSCH. In other words, if the number of TCI states indicated in the DCI scheduling the PDSCH is 2, it can be regarded as a single PDCCH-based NC-JT transmission, and if the number of TCI states is 1, it can be regarded as a single-TRP transmission. The TCI states indicated in the above DCI may correspond to one or two TCI states among the TCI states activated by MAC-CE. If the TCI states of DCI correspond to two TCI states activated by MAC-CE, a correspondence relationship is established between the TCI codepoint indicated in DCI and the TCI states activated by MAC-CE, and the MAC corresponding to the TCI codepoint -This may be when there are two TCI states activated with CE.

As another example, if at least one codepoint among all codepoints in the TCI state field in the DCI indicates two TCI states, the terminal may consider that the base station can transmit based on the single-DCI based multi-TRP method. You can. At this time, at least one codepoint indicating two TCI states within the TCI state field can be activated through Enhanced PDSCH TCI state activation/deactivation MAC-CE.

Figure 21 is a diagram showing the Enhanced PDSCH TCI state activation/deactivation MAC-CE structure. The meaning of each field in the MAC CE and the values that can be set for each field are as follows.

In Figure 21, if the value of the C ₀ field (21-05) is 1, the corresponding MAC-CE adds the TCI state ID _0,2 field (21-15) in addition to the TCI state ID _0,1 field (21-10). It can be included. This means that TCI state ID _0,1 and TCI state ID _0,2 are activated for the 0th codepoint of the TCI state field included in the DCI. If the base station indicates the corresponding codepoint to the terminal, the terminal has two TCI states. You can receive instructions. If the value of the C ₀ field (21-05) is 0, the corresponding MAC-CE cannot include the TCI state ID _0,2 field (21-15), which is the 0th codepoint of the TCI state field included in the DCI. This means that one TCI state corresponding to TCI state ID _0,1 is activated.

The above settings may be independent for each cell or BWP. For example, a PCell may have a maximum of two activated TCI states corresponding to one TCI codepoint, while a specific SCell may have a maximum of one activated TCI state corresponding to one TCI codepoint. In this case, it can be considered that NC-JT transmission is configured in the PCell, while NC-JT transmission is not configured in the SCell described above.

[How to distinguish between Single-DCI based Multi-TRP PDSCH repetitive transmission techniques (TDM/FDM/SDM)]

Next, we describe how to distinguish between single-DCI-based multi-TRP PDSCH repetitive transmission techniques. The UE may receive instructions from the base station for different single-DCI-based multi-TRP PDSCH repetitive transmission techniques (e.g., TDM, FDM, SDM) depending on the value indicated in the DCI field and higher layer signaling settings. [Table 24] below shows a method of distinguishing between single or multiple TRP-based techniques indicated to the UE according to the value of a specific DCI field and upper layer signaling settings.

[Table 24]

In Table 24 above, each column can be explained as follows.

- Number of TCI states (column 2): This refers to the number of TCI states indicated by the TCI state field in the DCI, and can be 1 or 2.

- Number of CDM groups (column 3): This refers to the number of different CDM groups of DMRS ports indicated by the Antenna port field in DCI. It can be 1, 2 or 3.

- RepetitionNumber setting and indication conditions (column 4): There are three conditions depending on whether repetitionNumber is set for all TDRA entries that can be indicated by the Time Domain Resource Allocation field in DCI and whether the actually indicated TDRA entry has repetitionNumber settings. You can.

■ Condition 1: At least one of all TDRA entries that can be indicated by the Time Domain Resource Allocation field includes a setting for repetitionNumber, and the TDRA entry indicated by the Time Domain Resource Allocation field in the DCI includes a setting for repetitionNumber greater than 1. If you do

■ Condition 2: When at least one of all TDRA entries that can be indicated by the Time Domain Resource Allocation field includes a setting for repetitionNumber, and the TDRA entry indicated by the Time Domain Resource Allocation field in the DCI does not contain a setting for repetitionNumber.

■ Condition 3: If all TDRA entries that can be indicated by the Time Domain Resource Allocation field do not include a setting for repetitionNumber.

- RepetitionScheme setting related (column 5): Indicates whether repetitionScheme, which is upper layer signaling, is set. RepetitionScheme, which is upper layer signaling, can be set to one of 'tdmSchemeA', 'fdmSchemeA', and 'fdmSchemeB'.

- Transmission technique indicated to the terminal (column 6): Refers to single or multiple TRP techniques indicated according to each combination (column 1) represented in Table 24 above.

■ Single-TRP: Refers to single TRP-based PDSCH transmission. If the terminal has been configured with pdsch-AggegationFactor in the upper layer signaling PDSCH-config, the terminal can receive a single TRP-based repetitive PDSCH transmission scheduled for the number of times configured. Otherwise, the UE can schedule a single PDSCH transmission based on a single TRP.

■ Single-TRP TDM scheme B: refers to PDSCH repetitive transmission based on time resource division between slots based on a single TRP. According to Condition 1 related to repetitionNumber described above, the terminal repeatedly transmits the PDSCH on the time dimension as many slots as the repetitionNumber number greater than 1 set in the TDRA entry indicated by the Time Domain Resource Allocation field. At this time, the same start symbol and symbol length of the PDSCH indicated by the TDRA entry are applied to each slot as many repetitionNumber times, and the same TCI state is applied to each PDSCH repetition transmission. This technique is similar to the slot aggregation method in that it performs repeated PDSCH transmission between slots on time resources, but differs from slot aggregation in that it can dynamically determine whether to direct repeated transmission based on the Time Domain Resource Allocation field in DCI. there is.

■ Multi-TRP SDM: refers to a multi-TRP based spatial resource division PDSCH transmission method. This is a method of receiving layers separately from each TRP. Although it is not a repetitive transmission method, it can increase the reliability of PDSCH transmission in that it can be transmitted by lowering the coding rate by increasing the number of layers. The UE can receive the PDSCH by applying the two TCI states indicated through the TCI state field in the DCI to each of the two CDM groups indicated by the base station.

■ Multi-TRP FDM scheme A: refers to a multi-TRP based frequency resource division PDSCH transmission method. It has one PDSCH transmission location (occasion), so it is not repetitive transmission like multi-TRP SDM, but increases the amount of frequency resources and lowers the coding rate to provide high It is a technique that can be transmitted with reliability. Multi-TRP FDM scheme A can apply two TCI states indicated through the TCI state field in DCI to frequency resources that do not overlap each other. If the PRB bundling size is determined to be wideband, the UE applies the first TCI state to the first ceil (N/2) RBs when the number of RBs indicated by the Frequency Domain Resource Allocation field is N, and the remaining floor (N/ 2) RBs receive by applying the second TCI state. Here, ceil(.) and floor(.) are operators that mean rounding up and rounding down to the first decimal place. If the PRB bundling size is set to 2 or 4, even-numbered PRGs receive the first TCI state, and odd-numbered PRGs receive the second TCI state.

■ Multi-TRP FDM scheme B: refers to a multi-TRP based frequency resource division PDSCH repetitive transmission method. It has two PDSCH transmission positions (occasions), so the PDSCH can be transmitted repeatedly to each position. Multi-TRP FDM scheme B, like A, can apply two TCI states indicated through the TCI state field in DCI to frequency resources that do not overlap each other. If the PRB bundling size is determined to be wideband, the UE applies the first TCI state to the first ceil (N/2) RBs when the number of RBs indicated in the Frequency Domain Resource Allocation field is N, and the remaining floor (N/ 2) RBs receive by applying the second TCI state. Here, ceil(.) and floor(.) are operators that mean rounding up and rounding down to the first decimal place. If the PRB bundling size is set to 2 or 4, even-numbered PRGs receive the first TCI state, and odd-numbered PRGs receive the second TCI state.

■ Multi-TRP TDM scheme A: This refers to a PDSCH repetitive transmission scheme within a multi-TRP based time resource division slot. The terminal has two PDSCH transmission positions (occasions) within one slot, and the first reception position can be determined based on the start symbol and symbol length of the PDSCH indicated through the Time Domain Resource Allocation field in the DCI. The starting symbol of the second reception position of the PDSCH can be a position where a symbol offset is applied from the last symbol of the first transmission position by StartingSymbolOffsetK , which is upper layer signaling, and the transmission position can be determined by the symbol length indicated from this. If StartingSymbolOffsetK , which is upper layer signaling, is not set, the symbol offset can be considered 0.

■ Multi-TRP TDM scheme B: Refers to a PDSCH repetitive transmission scheme between multiple TRP-based time resource division slots. The terminal has one PDSCH transmission location (occasion) within one slot, and receives repeated transmissions based on the start symbol and symbol length of the same PDSCH during slots equal to the repetitionNumber number indicated through the Time Domain Resource Allocation field in the DCI. can do. If repetitionNumber is 2, the UE can receive PDSCH repetition transmissions in the first and second slots by applying the first and second TCI states, respectively. If repetitionNumber is greater than 2, the terminal can use different TCI state application methods depending on which tciMapping, which is upper layer signaling, is set. If tciMapping is set to cyclicMapping, the first and second TCI states are applied to the first and second PDSCH transmission positions, respectively, and this TCI state application method is equally applied to the remaining PDSCH transmission positions. If tciMapping is set to sequentialMapping, the first TCI state is applied to the first and second PDSCH transmission locations, the second TCI state is applied to the third and fourth PDSCH transmission locations, and this TCI state application method is used for the remaining The same applies to the PDSCH transmission location.

[DMRS-related]

Next, the antenna port field instructions included in DCI format 1_1 and DCI format 1_2 defined in [Table 7] described above will be described. The Antenna port field in DCI format 1_1 and 1_2 can be expressed as 4, 5, or 6 bits, and can be indicated through the following [Table 25-1] to [Table 25-8].

[Table 25-1] Antenna port(s) (1000 + DMRS port), dmrs-Type=1, maxLength=1

[Table 25-2] Antenna port(s) (1000 + DMRS port), dmrs-Type=1, maxLength=1

[Table 25-3] Antenna port(s) (1000 + DMRS port), dmrs-Type=1, maxLength=2

[Table 25-4] Antenna port(s) (1000 + DMRS port), dmrs-Type=1, maxLength=2

[Table 25-5]: Antenna port(s) (1000 + DMRS port), dmrs-Type=2, maxLength=1

[Table 25-6]: Antenna port(s) (1000 + DMRS port), dmrs-Type=2, maxLength=1

[Table 25-7]: Antenna port(s) (1000 + DMRS port), dmrs-Type=2, maxLength=2

[Table 25-8]: Antenna port(s) (1000 + DMRS port), dmrs-Type=2, maxLength=2

[Table 25-1] and [Table 25-2] are tables used when dmrs-type is specified as 1 and maxLength is specified as 1, and [Table 25-3] and [Table 25-4] are tables used when dmrs-Type= 1, this is the table used when maxLength=2 is specified, [Table 25-5] and [Table 25-6] are the tables used when dmrs-type=2, maxLength=1, [Table 25-7] and [Table 25] -8] indicates the DMRS port to be used when drms-tpye is 2 and maxLength is 2.

If the terminal receives a MAC-CE activating a code point indicating two TCI states for at least one code point in the TCI state field in the DCI, the terminal receives [Table 25-2], [Table 25-4] , the DMRS port can be indicated using [Table 25-6] and [Table 25-8], otherwise, the terminal will use [Table 25-1], [Table 25-3], [Table 25-5], The DMRS port can be indicated using [Table 25-7]. If the terminal is instructed to code points indicating two TCI states through the TCI state field, the terminal is [Table 25-2], [Table 25-4], [Table 25-6], [Table 25-8] ], you can receive entries indicating DMRS port numbers 1000, 1002, and 1003 for NC-JT scheduling purposes, and the corresponding entries are numbered 12 in [Table 25-2], number 31 in [Table 25-4], and [ It may be entry number 24 in [Table 25-6] and entry number 58 in [Table 25-8].

For DCI format 1_1, if the terminal has both upper layer signaling dmrs-DownlinkForPDSCH-MappingTypeA and dmrs-DownlinkForPDSCH-MappingTypeB configured, the bit length of the Antenna port field in DCI format 1_1 is max{x- _A , x _B } It can be determined as, where x _A and x _B can mean the bit length of the Antenna port field determined through dmrs-DownlinkForPDSCH-MappingTypeA and dmrs-DownlinkForPDSCH-MappingTypeB, respectively. If the PDSCH mapping type corresponding to the smaller of x _A and x _B is scheduled, |x _A -x _B | The number of MSB bits can be allocated as 0 bits and transmitted.

For DCI format 1_2, if the terminal has not configured antennaPortsFieldPresenceDCI-1-2 , which is upper layer signaling, the corresponding DCI format 1_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 enters the 0th entry in [Table 25-1], [Table 25-3], [Table 25-5], and [Table 25-7]. The DMRS port can be determined by assuming . If the terminal is configured with antennaPortsFieldPresenceDCI-1-2 , which is upper layer signaling, the bit length of the Antenna port field in DCI format 1_2 can be determined similarly to the case of DCI format 1_1 described above. If the terminal has configured both the 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 }, where x _A and x _B are the antenna port field determined through dmrs-DownlinkForPDSCH-MappingTypeA-DCI-1-2 and dmrs-DownlinkForPDSCH-MappingTypeB-DCI-1-2, respectively. It may mean bit length. If the PDSCH mapping type corresponding to the smaller of x _A and x _B is scheduled, |x _A -x _B | The number of MSB bits can be allocated as 0 bits and transmitted.

In [Table 25-1] to [Table 25-8], the numbers 1, 2, and 3 indicated by Number of DMRS CDM group(s) without data are CDMR group {0}, {0, 1}, {0, 1, 2}. DMRS port(s) is the index of the port used in order. Antenna port is indicated as DMRS port + 1000. The CDM group of DMRS is connected to the method of generating the DMRS sequence and the antenna port, as shown in [Table 26-1] and [Table 26-2]. [Table 26-1] is the parameters when using dmrs-type=1, and [Table 26-2] is the parameters when using dmrs-type=2.

[Table 26-1]: Parameters for PDSCH DM-RS dmrs-type=1.

[Table 26-2]: Parameters for PDSCH DM-RS dmrs-type=2.

The DMRS sequence according to each parameter is determined by Equation 3 below. In Equation 3, p means DMRS port, k means subcarrier index, l means OFDM symbol index, μ means subcarrier spacing, w _f (k') and w _t (l' ) refers to 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, represents the interval between CDM groups in terms of the number of subcarriers. In [Equation 3] is a scaling factor that means the ratio between EPRE (energy per RE) of PDSCH and EPRE of DMRS, It can be calculated as follows, depending on the number of CDM groups: 1, 2, or 3. The value may be 0 dB, -3 dB, or -4.77 dB.

[Equation 3]

When DMRS type 1 is used, if the terminal receives scheduling of a single codeword using [Table 25-1] and [Table 25-3] and is instructed to enter entries 2, 9, 10, 11, and 30, or [Table 25 -2] to schedule a single codeword and receive instructions for entries 2, 9, 10, 11, and 12, or to use [Table 25-4] to schedule a single codeword and receive instructions for entries 2, 9, 10, 11, 30, If entry number 31 is indicated or two codewords are scheduled, the terminal can be regarded as single-user MIMO scheduling. In other words, the terminal can assume that no other terminals are scheduled in all remaining orthogonal DMRS ports other than the DMRS port assigned to the scheduled PDSCH, and does not expect multi-user MIMO (MU-MIMO) scheduling. You can. In this case, 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.

When DMRS type 2 is used, if the terminal receives a single codeword scheduling using [Table 25-5] and [Table 25-7] and is instructed to enter entries 2, 10, and 23, or uses [Table 25-6] Use [Table 25-8] to schedule a single codeword and receive instructions for entries 2, 10, 23, and 24, or use [Table 25-8] to schedule a single codeword and receive instructions for entries 2, 10, 23, and 58, or use two codewords. When being scheduled, the terminal can be considered as single-user MIMO scheduling. That is, the UE may assume that no other UEs are scheduled in all remaining orthogonal DMRS ports other than the DMRS port assigned to the scheduled PDSCH, and may not expect multi-user MIMO scheduling. In this case, 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.

The terminal may not expect that the maximum number of front-loaded DMRS symbols is set to len2 through maxLength , which is upper layer signaling, and at the same time, more than one additional DMRS symbol is set through dmrs-AdditionalPosition , which is upper layer signaling.

The terminal may not expect that the actual number of front-loaded DMRS symbols, actual number of additional DMRS symbols, DMRS symbol positions, and DMRS type settings are different for all terminals scheduled for multi-user MIMO.

In the case of a terminal with a PRG size of 2 or 4, frequency resource allocation is consistent in the PRG unit grid for other terminals co-scheduled using other DMRS ports orthogonal within the same CDM group as the DMRS port instructed by the terminal. You can't expect something that doesn't happen.

In the case of PDSCH scheduled in DCI format 1_1 and 1_2, the UE has CDM groups indicated through the column “Number of DMRS CDM group(s) without data” in [Table 25-1] to [Table 25-8]. It can be assumed that it may include a DMRS port assigned to another terminal that can be co-scheduled through a multi-user MIMO method and may not be used for data transmission of the corresponding terminal, [Table 25-1] to [Table 25-1] to [ In Table 25-8, the values indicated through the column “Number of DMRS CDM group(s) without data” are 1, 2, and 3, which means that the indices of the CDM group corresponding to the above-mentioned meaning are CDM group 0, CDM group(s), respectively. It can be understood as corresponding to {0,1}, {0,1,2}.

If the UE is configured with the upper layer signaling, dmrs-FD-OCC-disableForRank1PDSCH, and the UE is allocated one DMRS port for PDSCH scheduling, the UE is connected to another orthogonal port within the same CDM group as the allocated one DMRS port. Among DMRS ports, a DMRS port using a different FD-OCC may not be expected to be assigned to another terminal.

Next, the antenna port field instructions included in DCI format 0_1 and DCI format 0_2 defined in [Table 5] described above will be described. Antenna port fields in DCI format 0_1 and 0_2 can be expressed as 3, 4, or 5 bits, and can be indicated through the following [Table 25-9] to [Table 25-24].

[Table 25-9] Antenna port(s), transform precoder is disabled, dmrs-Type=1, maxLength=1, rank = 1

[Table 25-10] Antenna port(s), transform precoder is disabled, dmrs-Type=1, maxLength=1, rank = 2

[Table 25-11] Antenna port(s), transform precoder is disabled, dmrs-Type=1, maxLength=1, rank = 3

[Table 25-12] Antenna port(s), transform precoder is disabled, dmrs-Type=1, maxLength=1, rank = 4

[Table 25-13] Antenna port(s), transform precoder is disabled, dmrs-Type=1, maxLength=2, rank = 1

[Table 25-14] Antenna port(s), transform precoder is disabled, dmrs-Type=1, maxLength=2, rank = 2

[Table 25-15] Antenna port(s), transform precoder is disabled, dmrs-Type=1, maxLength=2, rank = 3

[Table 25-16] Antenna port(s), transform precoder is disabled, dmrs-Type=1, maxLength=2, rank = 4

[Table 25-17] Antenna port(s), transform precoder is disabled, dmrs-Type=2, maxLength=1, rank=1

[Table 25-18] Antenna port(s), transform precoder is disabled, dmrs-Type=2, maxLength=1, rank=2

[Table 25-19] Antenna port(s), transform precoder is disabled, dmrs-Type=2, maxLength=1, rank =3

[Table 25-20] Antenna port(s), transform precoder is disabled, dmrs-Type=2, maxLength=1, rank =4

[Table 25-21] Antenna port(s), transform precoder is disabled, dmrs-Type=2, maxLength=2, rank=1

[Table 25-22] Antenna port(s), transform precoder is disabled, dmrs-Type=2, maxLength=2, rank=2

[Table 25-23] Antenna port(s), transform precoder is disabled, dmrs-Type=2, maxLength=2, rank=3

[Table 25-24] Antenna port(s), transform precoder is disabled, dmrs-Type=2, maxLength=2, rank=4

[Table 25-9] to [Table 25-12] are tables used when dmrs-type is specified as 1 and maxLength is specified as 1, and [Table 25-13] to [Table 25-16] are tables used when dmrs-Type= 1, maxLength=2 is the table used, and [Table 25-17] to [Table 25-20] are tables used when dmrs-type=2 and maxLength=1, [Table 25-21] to [Table 25]. -24] indicates the DMRS port to be used when drms-type is 2 and maxLength is 2.

For DCI format 0_1, if the terminal has both upper layer signaling dmrs-UplinkForPUSCH-MappingTypeA and dmrs-UplinkForPUSCH-MappingTypeB configured, the bit length of the Antenna port field in DCI format 0_1 is max{x- _A , x _B } It can be determined as, where x _A and x _B can mean the bit length of the Antenna port field determined through dmrs-UplinkForPUSCH-MappingTypeA and dmrs-UplinkForPUSCH-MappingTypeB, respectively. If the PUSCH mapping type corresponding to the smaller of x _A and x _B is scheduled, |x _A -x _B | The number of MSB bits can be allocated as 0 bits and transmitted.

For DCI format 0_2, if the terminal has not configured antennaPortsFieldPresenceDCI-0-2 , which is upper layer signaling, the corresponding 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 can determine the DMRS port by assuming the 0th entry in [Table 25-9] to [Table 25-24] above. If the terminal receives antennaPortsFieldPresenceDCI-0-2 , which is upper layer signaling, the bit length of the Antenna port field in DCI format 0_2 can be determined similarly to the case of DCI format 0_1 described above. If the terminal has configured 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 is max{x - _A , x _B }, where x _A and x _B are of the Antenna port field determined through dmrs-UplinkForPUSCH-MappingTypeA-DCI-0-2 and dmrs-UplinkForPUSCH-MappingTypeB-DCI-0-2, respectively. It may mean bit length. If the PDSCH mapping type corresponding to the smaller of x _A and x _B is scheduled, |x _A -x _B | The number of MSB bits can be allocated as 0 bits and transmitted.

In [Table 25-9] to [Table 25-24], the numbers 1, 2, and 3 indicated by Number of DMRS CDM group(s) without data are CDMR group {0}, {0, 1}, {0, 1, 2}. DMRS port(s) is the index of the port used in order. Antenna port is indicated as DMRS port + 1000. The CDM group of DMRS is connected to the method of generating the DMRS sequence and the antenna port, as shown in [Table 26-1a] and [Table 26-2a]. [Table 26-1a] is the parameters when using dmrs-type=1, and [Table 26-2a] is the parameters when using dmrs-type=2.

[Table 26-1a]: Parameters for PUSCH DM-RS dmrs-type=1.

[Table 26-2a]: Parameters for PUSCH DM-RS dmrs-type=2.

The DMRS sequence according to each parameter is determined by the following equation 3-1. In Equation 3-1, means the DMRS port, k means the subcarrier index, l means the OFDM symbol index, μ means the subcarrier spacing, and w _f (k') and w _t (l') are the k' values, respectively. It means FD-OCC (frequency domain orthogonal cover code) and TD-OCC (time domain orthogonal cover code) coefficient according to the l' value, represents the interval between CDM groups in terms of the number of subcarriers. In [Equation 3-1] is a scaling factor that means the ratio between EPRE (energy per RE) of PUSCH and EPRE of DMRS, It can be calculated as follows, depending on the number of CDM groups: 1, 2, or 3. The value may be 0 dB, -3 dB, or -4.77 dB.

[Equation 3-1]

If frequency hopping is not used, the UE may have to assume that dmrs-AdditionalPosition, which is upper layer signaling, is set to 'pos2', and up to two additional DMRS symbols can 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.

In the case of PUSCH scheduled in DCI format 0_1 and 0_2, the UE has CDM groups indicated through the column “Number of DMRS CDM group(s) without data” in [Table 25-9] to [Table 25-24]. It can be assumed that it may include a DMRS port assigned to another terminal that can be co-scheduled through a multi-user MIMO method and may not be used for data transmission of that terminal, [Table 25-9] to [Table 25-9] to [ In Table 25-24, the values indicated through the column “Number of DMRS CDM group(s) without data” are 1, 2, and 3, meaning that the indices of the CDM group corresponding to the above-mentioned meanings are CDM group 0, CDM group(s), respectively. It can be understood as corresponding to {0,1}, {0,1,2}.

<First Example: Improved DMRS type 1 and 2 support method supporting an increased number of orthogonal ports>

As an example of the present disclosure, a method for supporting improved DMRS types 1 and 2 that supports an increased number of orthogonal ports is described.

In the advanced standard of 5G, an improved DMRS type supports an increased number of orthogonal ports while maintaining the same RE usage and overhead compared to DMRS type 1 and DMRS type 2 supported in the initial standard of 5G for both uplink and downlink. Can support 1 and DMRS type 2. In the case of existing DMRS type 1, when the number of front loaded symbols is 1 and 2, up to 4 and 8 orthogonal DMRS ports can be supported, respectively, and in case of DMRS type 2, the number of front loaded symbols is 1 and 2. In this case, up to 6 and 12 orthogonal DMRS ports can be supported, respectively. Starting from these support items, for improved 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 for improved DMRS type 2, front When the number of loaded symbols is 1 and 2, up to 12 and 24 orthogonal DMRS ports can be supported, respectively. From now on, new DMRS types that support this increased number of orthogonal ports will be referred to as “improved 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 expanded names that can be called with improved functions from the existing DMRS types 1 and 2 cannot be ruled out. there is. The details described below focus on downlink, but can be similarly applied to uplink DMRS support.

If the UE supports enhanced DMRS types 1 and 2, the UE can report the UE capability of supporting enhanced DMRS types 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 in more detail, it may also be possible on a per FS (feature set) or per FSPC (feature set per component carrier) basis. In addition, the terminal capability report may be supported differently for each FR, and may be a terminal capability report limited to FR1. In addition, in the corresponding terminal capability report, as described above, in the case of improved 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 the improved DMRS type 2 can support up to 8 and 16 orthogonal DMRS ports, respectively. In this case, when the number of front loaded symbols is 1 and 2, the meaning of supporting up to 12 and 24 orthogonal DMRS ports, respectively, may be included. The terminal may report on enhanced DMRS types 1 and 2 through common terminal capabilities, and at this time, whether it supports only enhanced DMRS type 1, only enhanced DMRS type 2, or both enhanced DMRS types 1 and 2 is supported. You can also report whether or not enhanced DMRS types 1 and 2 are supported through individual terminal capabilities.

Additionally, if the terminal supports a dynamic switching function between the improved DMRS type and the existing DMRS type, the terminal can report the function through terminal capabilities. Here, the dynamic switching function between the existing type and the improved type means that the DMRS type set through upper layer signaling can be changed through MAC-CE, or it means that it is possible to select between the existing type and the improved type through DCI, or It can mean both. If reporting whether to support enhanced DMRS types 1 and 2 through a common terminal capability, the terminal reports whether to support the dynamic switching function for DMRS types 1 and 2 as a single terminal capability, and supports DMRS type 1 and enhanced DMRS It can be reported whether it supports only dynamic switching for type 1, only dynamic switching for DMRS type 2 and enhanced DMRS type 2, or whether both types support dynamic switching between existing and enhanced types. Differently, when reporting support for enhanced DMRS types 1 and 2 through common terminal capabilities or through individual terminal capabilities, the possibility of dynamic switching between the existing type and the improved type can be reported through individual terminal capabilities for each type. You can.

Additionally, when the terminal operates with enhanced DMRS type 1 or 2, and if the terminal supports existing DMRS type 1 or 2 and multi-user MIMO scheduling, the terminal can report the corresponding function through terminal capabilities. Here, multi-user MIMO scheduling may be a co-schedule between existing DMRS type 1 and improved DMRS type 1, or a co-schedule between existing DMRS type 2 and improved DMRS type 2. Similar to the above, the terminal capabilities regarding whether co-scheduling between the existing type and the improved type is possible are reported as common terminal capabilities, reporting that only co-scheduling is possible between the existing type 1 and the improved type 1, or the existing type 2 and the improved type. You can report that only co-schedule is possible between type 2, or you can report that co-schedule is possible between the existing type and the improved type for both types 1 and 2, and you can report it through individual terminal capabilities for each type.

For a UE that has reported the corresponding UE capabilities, the base station can configure the enhanced DMRS type 1 and 2 methods to the UE through upper layer signaling using the following methods.

- [Higher level configuration method 1] For example, the terminal can be configured to support the enhanced DMRS type within DMRS-DownlinkConfig, which is upper layer signaling.

■ [Higher layer setting method 1-1] dmrs-Type-r18, which is a higher layer signaling similar to dmrs-Type, which is a higher layer signaling that determines the existing type, can be set, and defines an improved DMRS type in addition to DMRS type 1 or 2. can be used to The terminal can set a new RRC IE called dmrs-Type-r18 in addition to dmrs-Type in DMRS-DownlinkConfig, which is the upper layer signaling, and DMRS type 1, 2, or improved DMRS type 1, 2 through this dmrs-Type-r18. One of them may be decided, or one of enhanced DMRS type 1 or 2 may be decided. For example, as shown in [Table 26-3] below, if dmrs-Type-r18 is set, one of DMRS type 2, enhanced DMRS type 1 or 2 can be determined, and the existing dmrs-Type will be ignored. 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 may be determined, and the existing dmrs-Type may be ignored, and if dmrs-Type-r18 is not set. If not, the DMRS type can be determined according to the setting method of dmrs-Type. When using this upper setting method, the terminal uses one of the existing DMRS type (e.g., DMRS type 1 or 2) and the improved type (e.g., improved DMRS type 1 or 2) for each PDSCH mapping type A or B. Only two methods can be used, and dynamic switching between the existing method and the improved method is not possible, or it may be a higher setting method that does not take dynamic switching itself into consideration. At this time, the RRC IE name dmrs-Type-r18 is only an example, and the actual name of the RRC IE may be different from this.

[Table 26-3]

■ [Higher setting method 1-2] The existing dmrs-Type uses the existing meaning of determining either DMRS type 1 or 2, but adds a new RRC IE that has the meaning of whether improved DMRS type 1 or 2 is available or not. It can be set to . As shown in [Table 26-4] below, if the terminal has not been configured for dmrs-Type, which is upper layer signaling, from the base station, and has not been configured for enhanced-Dmrs-Type-r18, the terminal uses the existing method for DMRS type 1. Support is available. Additionally, if the terminal is not set for dmrs-Type and enhanced-Dmrs-Type-r18 is set to enabled, this may mean that the terminal can support the enhanced method for DMRS type 1. 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 additional upper layer signaling. Whether dynamic switching can be set from the base station through dynamicSwitchType, which is layer signaling.

[Table 26-4]

- [Higher level configuration method 2] To support the improved DMRS type, the terminal does not use DMRS-DownlinkConfig, which is upper layer signaling, and can independently configure through the new RRC IE that the improved DMRS type is supported within PDSCH-Config. As shown in [Table 26-5] below, if the UE has not received upper layer signaling, enhanced-Dmrs-Type-r18 configuration from the base station, the UE can determine the DMRS type according to the existing DMRS-DownlinkConfig settings. If the terminal has received enhanced-Dmrs-Type-r18, which is upper layer signaling, from the base station, the terminal can use the enhanced method for the DMRS type determined according to the existing DMRS-DownlinkConfig setting. 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 additional upper layer signaling. Whether dynamic switching can be set from the base station through dynamicSwitchType, which is layer signaling.

[Table 26-5]

From now on, various support methods for determining specific RE mapping and OCC for enhanced DMRS types 1 and 2 are described.

[Enhanced DMRS type 1 support method 1]

As an example of the method for supporting the above-described improved DMRS type 1, when using the improved DMRS type 1 based on [Equation 4] and [Table 26-6] below, the time and frequency resource mapping of DMRS RE and the time and frequency resource mapping at that time FD-OCC and TD-OCC coefficients can be determined.

[Equation 4]

[Table 26-6]: Parameters for [Enhanced DMRS type 1 support method 1]

[Improved DMRS type 1 support method 1] based on [Equation 4] and [Table 26-6] uses a total of 4 CDM groups, and in the case of 1 front loaded DMRS symbol, 2 DMRS ports in each CDM group. can be included, so a total of 8 orthogonal DMRS ports can be supported. In the case of 2 front loaded DMRS symbols, each CDM group can include 4 DMRS ports, so a total of 16 orthogonal DMRS ports can be supported. Compared to the existing DMRS type 1, where the interval between REs assigned to a specific DMRS port within the same CDM group was 2 RE, since 4 CDM groups are supported, the interval can be increased to 4 RE. Since the number of CDM groups has been increased while maintaining the number of DMRS ports in the CDM group, scheduling of PDSCH to be transmitted with DMRS may be limited to 2 RB units. In [Equation 4] is a scaling factor that means the ratio between EPRE (energy per RE) of PDSCH and EPRE of DMRS, It can be calculated as follows, depending on the number of CDM groups: 1, 2, 3, or 4. The value may be 0 dB, -3 dB, -4.77 dB, or -6 dB.

[Enhanced DMRS type 1 support method 2]

As another example of the method for supporting the above-described improved DMRS type 1, when using the improved DMRS type 1 based on [Equation 5] and [Table 26-7] below, time and frequency resource mapping of DMRS RE and the The FD-OCC and TD-OCC coefficients can be determined.

[Equation 5]

[Table 26-7]: Parameters for [Enhanced DMRS type 1 support method 2]

[Improved DMRS type 1 support method 2] based on [Equation 5] and [Table 26-7] uses a total of 4 CDM groups, and in the case of 1 front loaded DMRS symbol, 2 DMRS ports in each CDM group. can be included, so a total of 8 orthogonal DMRS ports can be supported. In the case of 2 front loaded DMRS symbols, each CDM group can include 4 DMRS ports, so a total of 16 orthogonal DMRS ports can be supported. Since the number of CDM groups has been increased while maintaining the number of DMRS ports in the CDM group, scheduling of PDSCH to be transmitted with DMRS may be limited to 2 RB units. Like the existing DMRS type 1, the spacing between REs assigned to specific DMRS ports within the same CDM group can be maintained at 2 RE, but the DMRS density of a specific RB among the two RBs for each DMRS port is high and the DMRS density of the remaining one RB is high. A situation may occur where DMRS density is low. For example, in the case of DMRS ports 1000 to 1003, the DMRS density of the even-numbered RB among the allocated RBs is twice that of the odd-numbered RB, but in the case of DMRS ports 1004 to 1008, the opposite situation may be present. In [Equation 5] is a scaling factor that means the ratio between EPRE (energy per RE) of PDSCH and EPRE of DMRS, It can be calculated as follows, depending on the number of CDM groups: 1, 2, 3, or 4. The value may be 0 dB, -3 dB, -4.77 dB, or -6 dB.

[Enhanced DMRS type 1 support method 3]

As another example of the method for supporting the above-described improved DMRS type 1, when using the improved DMRS type 1 based on [Equation 3] and [Table 26-1-1] below, the time and frequency resources of DMRS RE Mapping and the FD-OCC and TD-OCC coefficients at that time can be determined. At this time, the difference from the existing DMRS type 1 is that if the number of front loaded symbols is 1, DMRS ports 1000 to 1003 can be indicated for the even-numbered RB where the PDSCH is scheduled, and DMRS for the odd-numbered RB Instructions for ports 1004 to 1007 may be possible, and if the number of front loaded symbols is 2, instructions for DMRS ports 1000 to 1007 may be possible for the even-numbered RBs on which the PDSCH is scheduled, and DMRS for the odd-numbered RBs This means that instructions for ports 1008 to 1015 are possible. Therefore, as shown in [Table 26-1-1] below, if the DMRS port indices differ by 8, the FD-OCC and TD-OCC coefficients may be the same. Alternatively, only the indication for DMRS ports 1000 to 1007 is supported using the above-mentioned [Table 26-1], and additional indication is given as to whether the DMRS RE is placed in the even or odd RB in the frequency resource where the PDSCH is scheduled. Therefore, even if it is the same DMRS port 1000, a method of discriminating according to the RB where the DMRS RE is placed can be used. Specific DMRS port indication and RB location indication methods will be described later.

[Table 26-1-1] Parameters for [Enhanced DMRS type 1 support method 3]

[Enhanced DMRS type 1 support method 3] based on [Equation 3] and [Table 26-1-1] uses a total of two CDM groups, and in the case of one front loaded DMRS symbol, two CDM groups are used in each CDM group. DMRS ports can be included and DMRS ports are allocated to even-numbered RBs and odd-numbered RBs, so a total of 8 orthogonal DMRS ports can be supported. In the case of 2 front loaded DMRS symbols, each CDM group has 4 DMRS ports. Since it can be included, a total of 16 orthogonal DMRS ports can be supported. Since DMRS is allocated to even-numbered RBs and odd-numbered RBs while maintaining the number of DMRS ports and CDM groups in the CDM group, scheduling of PDSCH to be transmitted with DMRS may be limited to units of 3 or more RBs.

[Enhanced DMRS type 2 support method 1]

As an example of the method for supporting the above-described improved DMRS type 2, when using the improved DMRS type 2 based on [Equation 6] and [Table 26-8] below, the time and frequency resource mapping of DMRS RE and the time and frequency resource mapping at that time FD-OCC and TD-OCC coefficients can be determined.

[Equation 6]

[Table 26-8]: Parameters for [Enhanced DMRS type 2 support method 1]

[Improved DMRS type 2 support method 1] based on [Equation 6] and [Table 26-8] uses a total of 3 CDM groups, and in the case of 1 front loaded DMRS symbol, 4 DMRS ports in each CDM group. can be included, so a total of 12 orthogonal DMRS ports can be supported. In the case of two 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 in the CDM group was increased while maintaining the number of CDM groups, the scheduling of the PDSCH to be transmitted with the DMRS can be maintained in units of 1 RB as before, but the location of the DMRS RE is at a specific location within the RB. Because it is concentrated, DMRS channel estimation performance can be secured when scheduling PDSCH for two or more RBs. For example, in DMRS ports 1000 to 1003 in CDM group 0, the RE position in the RB is located in the 0th to 4th subcarriers, so DMRS is concentrated only on low index subcarriers in RB, so DMRS channel estimation performance for high index subcarriers This may fall. In [Equation 6] is a scaling factor that means the ratio between EPRE (energy per RE) of PDSCH and EPRE of DMRS, It can be calculated as follows, depending on the number of CDM groups: 1, 2, or 3. The value may be 0 dB, -3 dB, or -4.77 dB.

[Enhanced DMRS type 2 support method 2]

As another example of the method for supporting the above-described improved DMRS type 2, when using the improved DMRS type 2 based on [Equation 3] and [Table 26-2-1] below, the time and frequency resources of DMRS RE Mapping and the FD-OCC and TD-OCC coefficients at that time can be determined. At this time, similar to the above-described [Improved DMRS type 1 support method 3], the difference from the existing DMRS type 2 is that DMRS ports 1000 to 1011 can be indicated for the even-numbered RB where the PDSCH is scheduled, and for the odd-numbered RB, This means that instructions for DMRS ports 1012 to 1023 are possible for the RB. Therefore, as shown in [Table 26-2-1] below, if the DMRS port index is different by 12, the FD-OCC and TD-OCC coefficients may be the same. Alternatively, using the above-mentioned [Table 26-2], only the indication for DMRS port 1000 to 1011 is supported, and additional indication is given as to whether the DMRS RE is placed in the even or odd RB in the frequency resource where the PDSCH is scheduled. Therefore, even if it is the same DMRS port 1000, a method of discriminating according to the RB where the DMRS RE is placed can be used. Specific DMRS port indication and RB location indication methods will be described later.

[Table 26-2-1] Parameters for [Enhanced DMRS type 2 support method 2]

[Improved DMRS type 2 support method 2] based on [Equation 3] and [Table 26-2-1] uses a total of 3 CDM groups, and in the case of 1 front loaded DMRS symbol, 2 CDM groups are used in each CDM group. DMRS ports can be included and DMRS ports are allocated to even-numbered RBs and odd-numbered RBs, so a total of 12 orthogonal DMRS ports can be supported. In the case of 2 front loaded DMRS symbols, each CDM group has 4 DMRS ports. Since it can be included, a total of 24 orthogonal DMRS ports can be supported. Since DMRS is allocated to even-numbered RBs and odd-numbered RBs while maintaining the number of DMRS ports and CDM groups in the CDM group, scheduling of PDSCH to be transmitted with DMRS may be limited to units of 3 or more RBs.

<Example 1-1: Additional support method for improved DMRS types 1 and 2 supporting an increased number of orthogonal ports>

As an embodiment of the present disclosure, [Improved DMRS type 1 support method 1], [Improved DMRS type 1 support method 2], [Improved DMRS type 1 support method 3], [Improved DMRS type 2 support] in the above-described first embodiment In addition to [Method 1] and [Enhanced DMRS type 2 support method 2], additional support methods for improved DMRS types 1 and 2 that support an increased number of orthogonal ports are described.

[Enhanced DMRS type 1 support method 4]

As another example of the method for supporting the above-described improved DMRS type 1, when using the improved DMRS type 1 based on [Equation 5-1] and [Table 26-1-2] below, the time and frequency of DMRS RE Resource mapping and the FD-OCC and TD-OCC coefficients at that time can be determined.

[Equation 5-1]

[Table 26-1-2] Parameters for [Enhanced DMRS type 1 support method 4]

[Enhanced DMRS type 1 support method 4] based on [Equation 5-1] and [Table 26-1-2] uses a total of two CDM groups, and in the case of one front loaded DMRS symbol, each CDM group Four DMRS ports can be included, and in the case of two front loaded DMRS symbols, each CDM group can include eight DMRS ports, so a total of 16 orthogonal DMRS ports can be supported. Since the number of DMRS ports in the CDM group was increased while maintaining the number of CDM groups of the existing DMRS type 1 (2), the scheduling of the PDSCH to be transmitted with the DMRS can be maintained in units of 1 RB as before, and the existing DMRS can be mapped to the same RE location as DMRS type 1. However, the existing DMRS type 1 assumes that the channels of two REs (for example, RE#0 and RE#2) located 2 REs apart are the same, and applies OCC to the two REs to distinguish orthogonal ports, and 1 In the case of front loaded DMRS symbols, a total of 6 REs are used within 1 RB per port, so 3 OCCs of length 2 were used. Meanwhile, based on [Improved DMRS type 1 support method 4], for one front loaded DMRS symbol, a total of 6 REs are used within 1 RB per port, and one OCC of length 6 is used for a total of 4 Orthogonal ports can be distinguished. At this time, an OCC of length 6 is applied to 6 REs, and each RE may exist at a distance of 2 REs from each other. In other words, because OCC must be applied by considering six REs with relative RE positions of 0, 2, 4, 6, 8, and 10, respectively, as the same channel, 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 channels with less frequency selective characteristics. In [Table 26-1-2], the values of A, B, to C can be determined to ensure orthogonality between all ports among OCCs with a length of 6, for example, A = 1, B = , C = may be possible, and other values are not excluded. These values of A, B, to C are defined in advance in the standard and promised by the base station and the terminal, set to the terminal through upper layer signaling, activated to the terminal through MAC-CE, or dynamically indicated to the terminal through DCI. Alternatively, the terminal may be notified through a combination of these signalings. In [Equation 5-1] above, is a scaling factor that means the ratio between EPRE (energy per RE) of PDSCH and EPRE of DMRS, It can be calculated as follows, depending on the number of CDM groups: 1 or 2. The value of may be 0 dB or -3 dB.

[Enhanced DMRS type 1 support method 5]

As another example of the method for supporting the above-described improved DMRS type 1, when using the improved DMRS type 1 based on [Equation 5-2] and [Table 26-1-3] below, the time and frequency of DMRS RE Resource mapping and the FD-OCC and TD-OCC coefficients at that time can be determined.

[Equation 5-2]

[Table 26-1-3] Parameters for [Enhanced DMRS type 1 support method 5]

[Improved DMRS type 1 support method 5] based on [Equation 5-2] and [Table 26-1-3] uses a total of two CDM groups, and in the case of one front loaded DMRS symbol, each CDM group Four DMRS ports can be included, and in the case of two front loaded DMRS symbols, each CDM group can include eight DMRS ports, so a total of 16 orthogonal DMRS ports can be supported. Since the number of DMRS ports in the CDM group was increased while maintaining the number of CDM groups of the existing DMRS type 1 (2), the scheduling of the PDSCH to be transmitted with the DMRS can be maintained in units of 1 RB as before, and the existing DMRS can be mapped to the same RE location as DMRS type 1. However, the existing DMRS type 1 assumes that the channels of two REs (for example, RE#0 and RE#2) located 2 REs apart are the same, and applies OCC to the two REs to distinguish orthogonal ports, and 1 In the case of front loaded DMRS symbols, a total of 6 REs are used within 1 RB per port, so 3 OCCs of length 2 were used. Meanwhile, based on [Improved DMRS type 1 support method 5], for one front loaded DMRS symbol, a total of 6 REs are used within 1 RB per port, and one OCC of length 6 is used for a total of 4 Orthogonal ports can be distinguished. At this time, an OCC of length 6 is applied to 6 REs, and each RE may exist at a distance of 2 REs from each other. In other words, because OCC must be applied by considering six REs with relative RE positions of 0, 2, 4, 6, 8, and 10, respectively, as the same channel, 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 channels with less frequency selective characteristics. In [Table 26-1-3], the values of A, B, to C can be determined to ensure orthogonality between all ports among OCCs with a length of 6, for example, A = 1, B = , C = may be possible, and other values are not excluded. These values of A, B, to C are defined in advance in the standard and promised by the base station and the terminal, set to the terminal through upper layer signaling, activated to the terminal through MAC-CE, or dynamically indicated to the terminal through DCI. Alternatively, the terminal may be notified through a combination of these signalings. In [Equation 5-2] above, is a scaling factor that means the ratio between EPRE (energy per RE) of PDSCH and EPRE of DMRS, It can be calculated as follows, depending on the number of CDM groups: 1 or 2. The value of may be 0 dB or -3 dB.

[Enhanced DMRS type 1 support method 6]

As another example of the method for supporting the above-described improved DMRS type 1, when using the improved DMRS type 1 based on [Equation 5-3] and [Table 26-1-4] below, the time and frequency of DMRS RE Resource mapping and the FD-OCC and TD-OCC coefficients at that time can be determined.

[Equation 5-3]

[Table 26-1-4] Parameters for [Enhanced DMRS type 1 support method 6]

[Improved DMRS type 1 support method 6] based on [Equation 5-3] and [Table 26-1-4] uses a total of two CDM groups, and in the case of one front loaded DMRS symbol, each CDM group Since 4 DMRS ports can be included, up to 8 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 16 orthogonal DMRS ports can be supported. there is. Since the number of DMRS ports in the CDM group has been increased while maintaining the number of CDM groups of 2 in the existing DMRS type 1, and the OCC length for this has been increased to 4, scheduling of the PDSCH to be transmitted with DMRS will be used in units of 2 RBs. and the DMRS can be mapped to the same RE location as the existing DMRS type 1. However, the existing DMRS type 1 assumes that the channels of two REs (for example, RE#0 and RE#2) located 2 REs apart are the same, and applies OCC to the two REs to distinguish orthogonal ports, and 1 In the case of front loaded DMRS symbols, a total of 6 REs are used within 1 RB per port, so 3 OCCs of length 2 were used. Meanwhile, based on [Enhanced DMRS type 1 support method 6], for one front loaded DMRS symbol, a total of 12 REs are used within 2 RBs per port, and OCC with a length of 4 applied to 4 adjacent REs A total of four orthogonal antenna ports can be distinguished using . At this time, an OCC of length 4 is applied to 4 REs, and each of the 4 REs may exist at a distance of 2 REs from each other. In other words, since OCC must be applied by considering four REs with relative RE positions of 0, 2, 4, and 6 as the same channel, 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 channels with less frequency selective characteristics. [Table 26-1-4] above shows the ports 1000 to 1015 to have orthogonality between all ports among OCCs with a length of 4. Values can be determined, and the values in the table above are examples and do not exclude other values. In [Equation 5-3] above, is a scaling factor that means the ratio between EPRE (energy per RE) of PDSCH and EPRE of DMRS, It can be calculated as follows, depending on the number of CDM groups: 1 or 2. The value of may be 0 dB or -3 dB.

[Enhanced DMRS type 2 support method 3]

When using the improved DMRS type 2 based on [Equation 5-4] and [Table 26-2-2] below, the time and frequency resource mapping of DMRS RE and the FD-OCC and TD-OCC coefficients at that time can be determined. there is.

[Equation 5-4]

[Table 26-2-2]: Parameters for [Enhanced DMRS type 2 support method 3]

[Enhanced DMRS type 2 support method 3] based on [Equation 5-4] and [Table 26-2-2] uses a total of three CDM groups, and in the case of one front loaded DMRS symbol, each CDM group Since 4 DMRS ports can be included, 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. there is. Since the number of DMRS ports in the CDM group has been increased while maintaining the number of CDM groups, the scheduling of the PDSCH to be transmitted with the DMRS can be maintained in units of 1 RB as before, and can be installed in the same RE location as the existing DMRS type 2. DMRS can be mapped. However, the existing DMRS type 2 assumes that the channels of two consecutive REs are the same, and applies OCC to the two REs to distinguish orthogonal ports, and in the case of one front loaded DMRS symbol, within one RB per port. Since a total of 4 REs are used, 2 OCCs of length 2 were used. Meanwhile, based on [Improved DMRS type 2 support method 3], for one front loaded DMRS symbol, a total of 4 REs are used within 1 RB per port, and one OCC of length 4 is used for a total of 4 REs. Orthogonal ports can be distinguished. At this time, OCC of length 4 is applied to two consecutive sets of REs that are 6 RE apart from each other. That is, OCC is applied by considering four REs with relative RE positions of 0, 1, 6, and 7, respectively, as the same channel. Therefore, channel estimation performance may be lower than that of the existing DMRS type 2. Therefore, in the case of this improved DMRS type 2, it can be used for multi-user MIMO purposes in channels with less frequency selective characteristics. In [Equation 5-4] is a scaling factor that means the ratio between EPRE (energy per RE) of PDSCH and EPRE of DMRS, It can be calculated as follows, depending on the number of CDM groups: 1, 2, or 3. The value may be 0 dB, -3 dB, or -4.77 dB.

[Enhanced DMRS type 2 support method 4]

When using the improved DMRS type 2 based on [Equation 5-5] and [Table 26-2-3] or [Table 26-2-4], the time and frequency resource mapping of DMRS RE and the FD- OCC and TD-OCC coefficient can be determined.

[Equation 5-5]

[Table 26-2-3]: Parameters for [Enhanced DMRS type 2 support method 4]

[Table 26-2-4]: Parameters for [Enhanced DMRS type 2 support method 4]

[Enhanced DMRS type 2 support method 4] based on [Equation 5-5] and [Table 26-2-3] or [Table 26-2-4] uses a total of 6 CDM groups and 1 front In the case of loaded DMRS symbols, each CDM group can include 2 DMRS ports, so a total of 12 orthogonal DMRS ports can be supported. In the case of 2 front loaded DMRS symbols, each CDM group can include 4 DMRS ports, so a total of 12 orthogonal DMRS ports can be supported. It can support 24 orthogonal DMRS ports. Since the number of CDM groups has been increased while maintaining the number of DMRS ports in the CDM group, the scheduling of PDSCH to be transmitted with DMRS can be maintained in units of 1 RB as before, and some of the RE positions of existing DMRS type 2 DMRS can be mapped to the RE location. However, if the existing DMRS type 2 performed channel estimation using a total of 4 REs within 1 RB, when based on [Enhanced DMRS type 2 support method 4], the existing DMRS type 2 within 1 RB per port A total of 2 REs, which is half of , are used, and a total of 2 orthogonal ports can be distinguished using one OCC of length 2. At this time, because there are only two DMRS REs in one RB, channel estimation performance may be lower than that of the existing DMRS type 2. Therefore, in the case of this improved DMRS type 2, it can be used for multi-user MIMO purposes in channels with less frequency selective characteristics. In [Equation 5-5] is a scaling factor that means the ratio between EPRE (energy per RE) of PDSCH and EPRE of DMRS, It can be calculated as follows, depending on the number of CDM groups: 1, 2, 3, 4, 5, or 6. The value may be 0 dB, -3 dB, -4.77 dB, -6 dB, -6.99 dB, or -7.7 dB. At this time, if the number of CDM groups exceeds a certain number (for example, 4 or more), The value of may be constrained to a specific upper limit value. At this time, the specific number of CDM groups and their corresponding A specific upper limit value is set by upper layer signaling from the base station to the terminal, activated through MAC-CE signaling, indicated through L1 signaling, notified through a combination of upper layer signaling and L1 signaling, or fixedly defined in the standard. It can be.

For the above-described [Enhanced DMRS type 1 support method 1] to [Enhanced DMRS type 1 support method 6] and [Enhanced DMRS type 2 support method 1] to [Enhanced DMRS type 2 support method 4], the terminal supports each support method. The terminal capability, which means that it is possible, can be reported to the base station. The corresponding terminal capability may be valid only for FR1, or may be valid for both FR1 and FR2. The maximum number of supported terminals is 8 for enhanced DMRS type 1 when using 1 front-loaded DMRS symbol, 16 when using 2 front-loaded DMRS symbols, and 1 front for enhanced DMRS type 2. It can mean that 12 are possible when using a -loaded DMRS symbol, and 24 are possible when using 2 front-loaded DMRS symbols. After receiving the corresponding terminal capability, the base station can set the corresponding higher layer signaling, which can be one of the above-described higher layer signaling setting methods or independent upper layer signaling.

The base station and the terminal support the support methods mentioned in the first embodiment ([Enhanced DMRS type 1 support method 1], [Enhanced DMRS type 1 support method 2], [Enhanced DMRS type 1 support method 3], [Enhanced DMRS type 2 support method 1] or [enhanced DMRS type 2 support method 2]) and additional support methods for enhanced DMRS types 1 and 2 described in this embodiment ([enhanced DMRS type 1 support method 4], [enhanced DMRS type At least one method among [Support method 1], [Enhanced DMRS type 1 support method 6], [Improved DMRS type 2 support method 3], or [Improved DMRS type 2 support method 4]) is configured through upper layer signaling. It can be supported 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.

<Second Embodiment: DCI-based dynamic indication method for improved DMRS types 1 and 2>

As an example of an embodiment of the present disclosure, a DCI-based DMRS port indication method for the above-described enhanced DMRS types 1 and 2 is described. The terminal can receive an indication about the DMRS port allocated during PDSCH scheduling from the base station through DCI format 1_1 or DCI format 1_2. As described above, DMRS port indication based on existing DMRS types 1 and 2 is possible through the Antenna port field in DCI format 1_1 and DCI format 1_2 using one of [Table 25-1] to [Table 25-8]. did.

When the terminal receives a DCI-based DMRS port indication for advanced DMRS types 1 and 2 from the base station, it can be expected to support up to one codeword. That is, the terminal can expect n1 to be set for maxNrofCodeWordsScheduledByDCI, which is upper layer signaling, from the base station.

Regarding various methods of supporting the improved DMRS types 1 and 2 defined in the above-described first embodiment, the methods indicated through the Antenna port field in DCI format 1_1 and DCI format 1_2 will be described in detail.

[DMRS port instruction method 1]

If the terminal receives [Enhanced DMRS type 1 support method 1] or [Enhanced DMRS type 1 support method 2], the terminal indicates DMRS port based on [Table 27-1] and [Table 27-2] below. can be performed. [Table 27-1] and [Table 27-2] are DMRS port indication tables that can be used when maxLength = 1 and 2, respectively, and maxLength can mean the maximum number of front-loaded symbols.

[Table 27-1] When using [DMRS port indication method 1], maxLength = 1

As described above, [Table 27-1] may be expressed in 6 bits that can indicate a total of 64 entries, and when considering various alternatives in [Table 27-1] by considering at least one of the following items: It can also be expressed as 4, 5, 6, or 7 bits.

- [Consideration 1-1] Related to processing of entry 12 (Number of DMRS CDM group(s) without data = 2, DMRS port: 0, 2, 3) in [Table 27-1] above

■ Entry number 12 (Number of DMRS CDM group(s) without data = 2, DMRS port: 0, 2, 3) in [Table 27-1] may exist in entry number 12 as in [Table 27-1] above. After listing all entries except the corresponding entry, it may exist in the last entry that is not a reserved entry, and because the entry is used for multiple TRP purposes, it is excluded from the DMRS port indication table for improved DMRS type 1 support. It could be.

■ The [Consideration 1-1] is based on independent upper layer signaling for the corresponding [Consideration 1-1], or is based on upper layer signaling for enhanced DMRS types 1 and 2 support described above, or is MAC-CE based. It can be activated or deactivated, dynamically indicated through PDCCH, or defined in the standard.

■ For example, when considering how to delete entry 12 (Number of DMRS CDM group(s) without data = 2, DMRS port: 0, 2, 3) among the corresponding [Considerations 1-1], the following [ You can create an alternative to [Table 27-1], such as [Table 27-1a].

[Table 27-1a] [DMRS port instruction method 1] used and [Consideration 1-1] example of applied alternative, maxLength = 1

- [Consideration 1-2] When defining a new entry, express all or some combinations of entries that can indicate rank 2, 3, and 4

■ In [Table 27-1] above, when defining a new entry, it may be possible to express all or some combinations of entries that can indicate rank 2. As in [Table 27-1] described above, if Number of DMRS CDM group(s) without data = 3, some 6 combinations ({0, 1},{2,3},{4,5},{0,2},{0,4},{2,4}), and as another example, rank 2 can be indicated. Among all combinations, entries may be configured for some of the three combinations ({0,1}, {2,3}, {4,5}) considering only the combinations for DMRS ports within the same CDM group, another example. Among all combinations that can be indicated by rank 2, the combinations for DMRS ports within the same CDM group ({0,1},{2,3},{4,5}) and the first two DMRS ports of CDM groups 1 and 2 It may be possible to configure an entry for one combination ({0,2}) considered, and as another example, it may be possible to configure an entry for 15 combinations that can indicate rank 2. In addition, the newly added case of Number of DMRS CDM group(s) without data = 4 can be similarly considered, and entry configuration according to a different expression method for some combinations for rank 2 indication may not be excluded. .

■ In [Table 27-1] above, when defining a new entry, it may be possible to express all or some combinations of entries that can indicate rank 3. As in the above-mentioned [Table 27-1], if Number of DMRS CDM group(s) without data = 3, consecutive DMRS port indexes among all combinations that can indicate rank 3, such as entries 25 to 26. It may be possible to configure entries for two combinations ({0-2}, {3-5}) considering only combinations with , and as another example, it may be possible to configure entries for 20 combinations, which are all combinations that can indicate rank 3. there is. In addition, the newly added case of Number of DMRS CDM group(s) without data = 4 can be similarly considered, and entry configuration according to a different expression method for some combinations for rank 3 indication may not be ruled out. .

■ In [Table 27-1] above, when defining a new entry, it may be possible to express all or some combinations of entries that can indicate rank 4. As shown in [Table 27-1] above, if Number of DMRS CDM group(s) without data = 3, for example, some two combinations of all combinations that can indicate rank 4, such as entries 27 to 28 ( It may be possible to configure entries for {0-3}, {2-5}), and as another example, one combination considering only combinations with consecutive DMRS port indices among all combinations capable of rank 4 indication ({0- 3}), it may be possible to configure entries, and as another example, it may be possible to configure entries for 15 combinations, which are all possible combinations of rank 4 instructions. In addition, the newly added case of Number of DMRS CDM group(s) without data = 4 can be similarly considered, and entry configuration according to a different expression method for some combinations for rank 4 indication may not be ruled out. .

■ The [Consideration 1-2] is based on independent upper layer signaling for the corresponding [Consideration 1-2], or is based on upper layer signaling for enhanced DMRS types 1 and 2 support described above, or is MAC-CE based. It can be activated or deactivated, dynamically indicated through PDCCH, or defined in the standard.

■ For example, among the corresponding [Considerations 1-2], if Number of DMRS CDM group(s) without data = 3, among all combinations that can indicate rank 2, combinations for DMRS ports within the same CDM group ({0, 1},{2,3},{4,5}) and one combination ({0,2}) considering the first two DMRS ports of CDM groups 1 and 2, and rank 3 indication is possible. Entry configuration for two combinations ({0-2},{3-5}) considering only combinations with consecutive DMRS port indices among all combinations, and those with consecutive DMRS port indices among all combinations that allow rank 4 indication. Consider the entry configuration for one combination ({0-3}) considering only the combination, and if Number of DMRS CDM group(s) without data = 4, rank 2 is sent to the DMRS port within the same CDM group among all combinations that can be indicated. combinations ({0,1},{2,3},{4,5},{6,7}) and one combination considering the first two DMRS ports of CDM groups 1 and 2 ({0,2 }), an entry configuration for two combinations ({0-2},{3-5}) considering only combinations with consecutive DMRS port indices among all combinations that can indicate rank 3, and rank 4 If we consider the entry configuration for one combination ({0-3}, {4-7}) considering only combinations with consecutive DMRS port indices among all combinations that can be indicated, the [Table 27-1b] below An alternative to [Table 27-1] can be created.

[Table 27-1b] Example of alternatives applied to [DMRS port instruction method 1] and [Consideration 1-2], maxLength = 1

- [Consideration 1-3] For existing and new entries, priority when sorting according to rank value (number of DMRS ports indicated) and Number of DMRS CDM group(s) without data value

■ In [Table 27-1] above, when sorting the entry index according to the rank value and the Number of DMRS CDM group(s) without data value for existing and new entries, you can consider which one to sort with high priority. As shown in [Table 27-1] above, you can first sort according to the Number of DMRS CDM group(s) without data value and then sort according to the rank value. As another example, first according to the rank value. After sorting, you can also use the subsequent sorting method according to the Number of DMRS CDM group(s) without data value.

■ The [Consideration 1-3] is based on independent upper layer signaling for the corresponding [Consideration 1-3], or is based on upper layer signaling for enhanced DMRS types 1 and 2 support described above, or is MAC-CE based. It can be activated or deactivated, dynamically indicated through PDCCH, or defined in the standard.

■ As an example, a method of sorting later according to the rank value may be used, and as another example, a method of first sorting according to the rank value and then sorting according to the Number of DMRS CDM group(s) without data value may be used, You can create an alternative to [Table 27-1], such as [Table 27-1c] below.

[Table 27-1c] [DMRS port instruction method 1] used and [Considerations 1-3] an example of the applied alternative, maxLength = 1

- [Consideration 1-4] Excluding specific rank values for existing and new entries

■ In [Table 27-1] above, a method of excluding specific rank values that are not suitable for multi-user MIMO for existing and new entries can be considered. The excluded rank value may include at least one of ranks 2, 3, and 4, and the combination of excluded rank values and the minimum excluded rank value may be defined in the standard or set by higher layer signaling.

■ Alternatively, for a specific value of Number of DMRS CDM group(s) without data, a specific rank value may be excluded. For example, in the case of a large value of Number of DMRS CDM group(s) without data, such as 3 or 4, one can expect a large number of terminals that can be supported by multi-user MIMO, but in this case, use of a large value of rank may affect other users. This is because the number of CDM groups that can be scheduled may decrease.

■ The corresponding [Considerations 1-4] are based on independent upper layer signaling for the corresponding [Considerations 1-4], or based on upper layer signaling for enhanced DMRS types 1 and 2 support described above, or based on MAC-CE. It can be activated or deactivated, dynamically indicated through PDCCH, or defined in the standard.

■ For example, using a method in which values of rank 3 and 4 are excluded for all Number of DMRS CDM group(s) without data values among existing and new entries, [Table 27-1] such as [Table 27-1d] below ] can create alternatives.

[Table 27-1d] [DMRS port instruction method 1] used and [Consideration 1-4] an example of the applied alternative, maxLength = 1

- [Consideration 1-5] Excluding single-user MIMO-only entries from existing and new entries

■ In [Table 27-1] above, a method of excluding single-user MIMO-only entries for existing and new entries can be considered. Among the existing entries, the entry indexes that can be excluded as those used exclusively for single-user MIMO are 2, 9, 10, 11, and 12. The corresponding entries indicate that the DMRS port assigned to the terminal is included in all CDM groups to which the terminal can be assigned (for example, if Number of DMRS CDM group(s) without data = 2, the DMRS ports assigned to the terminal are (when included in two CDM groups), it may correspond to the case where, other than the assigned DMRS port, there is no remaining DMRS port orthogonal to the assigned DMRS port.

■ The corresponding [Considerations 1-5] are based on independent upper layer signaling for the corresponding [Considerations 1-5], or based on upper layer signaling for enhanced DMRS types 1 and 2 support described above, or based on MAC-CE. It can be activated or deactivated, dynamically indicated through PDCCH, or defined in the standard.

■ For example, by using a method of excluding all entries used exclusively for single-user MIMO from existing and new entries, an alternative to [Table 27-1], such as [Table 27-1e] below, can be created.

[Table 27-1e] An example of an alternative when using [DMRS port instruction method 1] and applying [Consideration 1-5], maxLength = 1

- [Consideration 1-6] How to consider at least one of the above-mentioned [Consideration 1-1] to [Consideration 1-5]

■ A method that considers at least one of [Considerations 1-1] to [Considerations 1-5] described above in [Table 27-1] or a combination of multiple considerations can be used.

■ The corresponding [Considerations 1-6] may be based on independent upper layer signaling for the corresponding [Considerations 1-6], or based on upper layer signaling for enhanced DMRS types 1 and 2 support described above, or based on the above [Considerations 1-6]. Based on a situation where a combination of at least one of the independent upper layer signaling for [Consideration 1-1] to [Consideration 1-5] is set simultaneously, activated or deactivated based on MAC-CE, or dynamically through PDCCH It may be indicated or defined in the standard.

■ For example, a method of deleting entry 12 (Number of DMRS CDM group(s) without data = 2, DMRS port: 0, 2, 3) for the above-mentioned [Consideration 1-1], and [Consideration 1 -2], if Number of DMRS CDM group(s) without data = 3, among all combinations that can indicate rank 2, combinations for DMRS ports within the same CDM group ({0,1},{2,3}, {4,5}), entry configuration for one combination ({0,2}) considering the first two DMRS ports of CDM groups 1 and 2, and Number of DMRS CDM group(s) without data = 4, Rank 2 Among all combinations that can be indicated, combinations for DMRS ports within the same CDM group ({0,1},{2,3},{4,5},{6,7}) and CDM group 1 and 2 A method of using the entry configuration for 1 combination ({0,2}) considering the first two DMRS ports, and all Number of DMRS CDM group(s) among existing and new entries for [Considerations 1-4] without By using a method in which values of ranks 3 and 4 are excluded for data values, an alternative to [Table 27-1], such as [Table 27-1f] below, can be created.

[Table 27-1f] [DMRS port instruction method 1] used and [Considerations 1-6] an example of the applied alternative, maxLength = 1

[Table 27-2] When using [DMRS port indication method 1], maxLength = 2

As described above, [Table 27-2] may be expressed in 7 bits that can indicate a total of 128 entries, and when considering various alternatives in [Table 27-2] by considering at least one of the following items: It can also be expressed as 5, 6, 7, or 8 bits.

- [Consideration 2-1] Related to processing of entry 12 (Number of DMRS CDM group(s) without data = 2, DMRS port: 0, 2, 3) in [Table 27-2] above

■ Entry 12 (Number of DMRS CDM group(s) without data = 2, DMRS port: 0, 2, 3) in [Table 27-2] may exist in entry 12 as in [Table 27-2] above. After listing all entries except the corresponding entry, it may exist in the last entry that is not a reserved entry, and because the entry is used for multiple TRP purposes, it is excluded from the DMRS port indication table for improved DMRS type 1 support. It could be.

■ The [Consideration 2-1] is based on independent upper layer signaling for the corresponding [Consideration 2-1], or is based on upper layer signaling for enhanced DMRS type 1 and 2 support described above, or is MAC-CE based. It can be activated or deactivated, dynamically indicated through PDCCH, or defined in the standard.

■ For example, when considering how to delete entry 12 (Number of DMRS CDM group(s) without data = 2, DMRS port: 0, 2, 3) among the corresponding [Considerations 2-1], the following [ You can create alternatives to [Table 27-2], such as [Table 27-2a].

[Table 27-2a] [DMRS port instruction method 1] used and [Consideration 2-1] example of applied alternative, maxLength = 2

- [Consideration 2-2] When defining a new entry, express all or some combinations of entries that can indicate rank 2, 3, and 4

■ In [Table 27-2] above, when defining a new entry, it may be possible to express all or some combinations of entries that can indicate rank 2. As in the above-mentioned [Table 27-2], if Number of DMRS CDM group(s) without data = 3 and Number of front-load symbols = 1, rank 2 indication is possible, for example, as entries 19 to 24. Entries may be configured for some of the six combinations ({0,1},{2,3},{4,5},{0,2},{0,4},{2,4}), As another example, among all combinations that can indicate rank 2, entries are configured for some three combinations ({0,1}, {2,3}, {4,5}) considering only combinations for DMRS ports within the same CDM group. This may be possible, and as another example, among all combinations that can indicate rank 2, combinations for DMRS ports within the same CDM group ({0,1},{2,3},{4,5}) and CDM group 1 , it may be possible to configure an entry for one combination ({0,2}) considering the first two DMRS ports of number 2, and as another example, it may be possible to configure an entry for 15 combinations, which are all combinations that can indicate rank 2. In addition, the newly added case of Number of DMRS CDM group(s) without data = 4 and Number of front-load symbols = 1 and 2 can be similarly considered, and other expressions for some combinations for rank 2 indication Organizing entries according to method may not be ruled out.

■ In [Table 27-2] above, when defining a new entry, it may be possible to express all or some combinations of entries that can indicate rank 3. As in the above-mentioned [Table 27-2], if Number of DMRS CDM group(s) without data = 3 and Number of front-load symbols = 1, for example, a rank 3 indication is given, such as entries 25 to 26. Among all possible combinations, it may be possible to configure entries for two combinations ({0-2}, {3-5}) considering only combinations with consecutive DMRS port indices, and as another example, all combinations that can be ranked 3 indicated. Entries may be configured for 20 types. In addition, the newly added case of Number of DMRS CDM group(s) without data = 4 and Number of front-load symbols = 1 and 2 can be similarly considered, and other expressions for some combinations for rank 3 indication Organizing entries according to method may not be ruled out.

■ In [Table 27-2] above, when defining a new entry, it may be possible to express all or some combinations of entries that can indicate rank 4. As in the above-mentioned [Table 27-2], if Number of DMRS CDM group(s) without data = 3 and Number of front-load symbols = 1, for example, a rank 4 indication is given, such as entries 27 to 28. It may be possible to configure entries for some two combinations ({0-3},{2-5}) among all possible combinations, and as another example, among all combinations that allow rank 4 indication, a combination with consecutive DMRS port indices It may be possible to configure an entry for one combination ({0-3}) considering only, and as another example, it may be possible to configure an entry for 15 combinations, which are all combinations for which rank 4 indication is possible. In addition, the newly added case of Number of DMRS CDM group(s) without data = 4 and Number of front-load symbols = 1 and 2 can be similarly considered, and other expressions for some combinations for rank 4 indication Organizing entries according to method may not be ruled out.

■ The [Consideration 2-2] is based on independent upper layer signaling for the corresponding [Consideration 2-2], or is based on upper layer signaling for enhanced DMRS types 1 and 2 support described above, or is MAC-CE based. It can be activated or deactivated, dynamically indicated through PDCCH, or defined in the standard.

■ For example, among the corresponding [Considerations 2-2], if Number of DMRS CDM group(s) without data = 3 and Number of front-load symbols = 1, among all combinations that can indicate rank 2, DMRS within the same CDM group Port combinations ({0,1},{2,3},{4,5}) and one combination ({0,2}) considering the first two DMRS ports of CDM groups 1 and 2. Entry configuration, entry configuration for two combinations ({0-2},{3-5}) considering only combinations with consecutive DMRS port indexes among all combinations capable of rank 3 indication, and all combinations capable of rank 4 indication. Among the combinations, consider the entry configuration for one combination ({0-3}) considering only combinations with consecutive DMRS port indices, Number of DMRS CDM group(s) without data = 4 and Number of front-load symbols = If 1, among all combinations that can indicate rank 2, combinations for DMRS ports within the same CDM group ({0,1},{2,3},{4,5},{6,7}) and CDM group An entry configuration for one combination ({0,2}) considering the first two DMRS ports 1 and 2, and two combinations considering only combinations with consecutive DMRS port indices among all combinations that can indicate rank 3 ({0 -2},{3-5}), and one combination considering only combinations with consecutive DMRS port indices among all combinations that can indicate rank 4 ({0-3},{4-7}) Entry configuration for, and if Number of DMRS CDM group(s) without data = 1 and Number of front-load symbols = 2, among all combinations that can indicate rank 2, combinations for DMRS ports within the same CDM group ({0 ,1},{8,9}), and if Number of DMRS CDM group(s) without data = 2 and Number of front-load symbols = 2, the same CDM group among all possible combinations of rank 2 Entry configuration for combinations of DMRS ports ({0,1},{2,3},{8,9},{10,11}), and Number of DMRS CDM group(s) without data = 3 and Number of front-load symbols = 2, among all combinations that can indicate rank 2, the combinations for DMRS ports within the same CDM group ({0,1},{2,3},{4,5},{8 ,9},{10,11},{12,13}), and if Number of DMRS CDM group(s) without data = 4 and Number of front-load symbols = 2, rank 2 can be indicated. Among all combinations, combinations for DMRS ports within the same CDM group ({0,1},{2,3},{4,5},{6,7},{8,9},{10,11}, {12,13},{14,15}), and if Number of DMRS CDM group(s) without data = 4 and Number of front-load symbols = 2, rank 3 is the same among all possible combinations. Entries for combinations ({0,1,8},{2,3,10},{4,5,12},{6,7,14}) for DMRS ports of consecutive indices within the CDM group Configuration, Number of DMRS CDM group(s) without data = 4 and Number of front-load symbols = 2, among all combinations that can indicate rank 4, combinations for DMRS ports of consecutive indices within the same CDM group ( Considering the entry configuration for {0,1,8,9},{2,3,10,11},{4,5,12,13},{6,7,14,15}), the following [ You can create an alternative to [Table 27-2], such as [Table 27-2b].

[Table 27-2b] [DMRS port instruction method 1] used and [Consideration 2-2] example of applied alternative, maxLength = 2

- [Consideration 2-3] For existing and new entries, priority when sorting according to rank value (number of DMRS ports indicated), Number of front-load symbols, and Number of DMRS CDM group(s) without data values.

■ In [Table 27-2] above, when sorting the entry index according to the rank value, Number of front-load symbols, and Number of DMRS CDM group(s) without data values for existing and new entries, which one has the highest priority? You may want to consider sorting. The above-mentioned [Table 27-2] sorts the Number of front-loaded symbols values in ascending order, and for entries with Number of front-load symbols = 1, within the same Number of front-load symbols value, Number of DMRS After sorting in ascending order according to the CDM group(s) without data value, and then sorting in ascending order according to the rank value (number of DMRS ports indicated) within the same Number of DMRS CDM group(s) without data value, For entries with Number of front-load symbols = 2, first, the entries with Number of DMRS CDM group(s) without data = 4 are sorted and placed in ascending order according to the rank value, and then Number of DMRS CDM group(s) without data is placed in ascending order. Data = 1,2,3 are sorted in ascending order, and when Number of DMRS CDM group(s) without data=1,2,3, according to the rank value within the same Number of DMRS CDM group(s) without data value. You can use the sorting method in ascending order.

■ As another example, first sort in ascending order according to the Number of front-load symbols value, and within the same Number of front-load symbols value, sort in ascending order according to the Number of DMRS CDM group(s) without data value, and then sort in ascending order according to the Number of front-load symbols value. Within the Number of DMRS CDM group(s) without data value, a method of sorting in ascending order according to the rank value (number of DMRS ports indicated) can be used.

■ As another example, first sort in ascending order according to the Number of front-load symbols value, and within the same Number of front-load symbols value, sort in ascending order according to the Number of DMRS CDM group(s) without data value, and then sort in ascending order according to the Number of front-load symbols value. Within the Number of DMRS CDM group(s) without data value, a method of sorting in ascending order according to the rank value (number of DMRS ports indicated) is used, and individual tables are defined for Number of front-load symbols=1 and 2. You can use it.

■ The [Consideration 2-3] is based on independent upper layer signaling for the corresponding [Consideration 2-3], or is based on upper layer signaling for enhanced DMRS types 1 and 2 support described above, or is MAC-CE based. It can be activated or deactivated, dynamically indicated through PDCCH, or defined in the standard.

■ For example, sort first in ascending order according to the Number of front-load symbols value, and within the same Number of front-load symbols value, sort in ascending order according to the Number of DMRS CDM group(s) without data value, and then sort in ascending order according to the Number of front-load symbols value. Within the DMRS CDM group(s) without data value, a method of sorting in ascending order according to the rank value (number of DMRS ports indicated) is used to generate alternatives to [Table 27-2], such as [Table 27-2c] below. can do.

[Table 27-2c] [DMRS port instruction method 1] used and [Considerations 2-3] an example of the applied alternative, maxLength = 2

- [Consideration 2-4] Excluding specific rank values for existing and new entries

■ In [Table 27-2] above, a method of excluding specific rank values that are not suitable for multi-user MIMO for existing and new entries can be considered. The excluded rank value may include at least one of ranks 2, 3, and 4, and the combination of excluded rank values and the minimum excluded rank value may be defined in the standard or set by higher layer signaling.

■ Alternatively, a specific rank value may be excluded for a specific value of Number of DMRS CDM group(s) without data or a specific value of Number of front-load symbols. For example, in the case of a large value of Number of DMRS CDM group(s) without data, such as 3 or 4, or if Number of front-load symbols = 2, a large number of terminals can be expected to be supported by multi-user MIMO. , In this case, using a large value of rank may reduce the number of CDM groups that can schedule other users.

■ The [Consideration 2-4] is based on independent upper layer signaling for the corresponding [Consideration 2-4], or is based on upper layer signaling for enhanced DMRS types 1 and 2 support described above, or is MAC-CE based. It can be activated or deactivated, dynamically indicated through PDCCH, or defined in the standard.

■ As an example, using a method in which values of ranks 3 and 4 are excluded for all Number of DMRS CDM group(s) without data values and all Number of front-load symbols values among existing and new entries, the following [Table 27- Alternatives to [Table 27-2] such as [2d] can be created.

[Table 27-2d] [DMRS port instruction method 1] used and [Considerations 2-4] an example of the applied alternative, maxLength = 2

- [Consideration 2-5] Excluding single-user MIMO-only entries from existing and new entries

■ In [Table 27-2] above, a method of excluding single-user MIMO-only entries for existing and new entries can be considered. Among the existing entries, the entry indexes that can be excluded as those used exclusively for single-user MIMO are 2, 9, 10, 11, 12, and 30. The corresponding entries indicate that the DMRS port assigned to the terminal is included in all CDM groups to which the terminal can be assigned (for example, if Number of DMRS CDM group(s) without data = 2 and Number of front-load symbols = 1) In this case, if the DMRS ports assigned to the terminal are included in two CDM groups), in addition to the assigned DMRS port, there is no remaining DMRS port orthogonal to the assigned DMRS port, or indicates ranks 3 and 4. It can correspond to an entry that does.

■ The [Consideration 2-5] is based on independent upper layer signaling for the corresponding [Consideration 2-5], or is based on upper layer signaling for enhanced DMRS types 1 and 2 support described above, or is MAC-CE based. It can be activated or deactivated, dynamically indicated through PDCCH, or defined in the standard.

■ For example, by using a method of excluding all entries used exclusively for single-user MIMO from existing and new entries, an alternative to [Table 27-2], such as [Table 27-2e] below, can be created.

[Table 27-2e] Use of [DMRS port instruction method 1] [Consideration 2-5] Example of applied alternative, maxLength = 2

- [Consideration 2-6] A method of considering a combination of at least one of the above-mentioned [Consideration 2-1] to [Consideration 2-5]

■ A method that considers at least one of [Considerations 2-1] to [Considerations 2-5] described above in [Table 27-2] or a combination of multiple considerations can be used.

■ The [Consideration 2-6] is based on independent upper layer signaling for the corresponding [Consideration 2-6], or is based on upper layer signaling for enhanced DMRS types 1 and 2 support described above, or is based on the [Consideration 2-6] described above. Based on a situation where a combination of at least one of the independent upper layer signaling for [Consideration 2-1] to [Consideration 2-5] is set simultaneously, activated or deactivated based on MAC-CE, or dynamically through PDCCH It may be indicated or defined in the standard.

■ For example, a method of deleting entry 12 (Number of DMRS CDM group(s) without data = 2, DMRS port: 0, 2, 3) for the above-mentioned [Consideration 2-1], and [Consideration 2 -5], a method of excluding single-user MIMO-only entries among existing and new entries can be used.

[DMRS port instruction method 2]

In addition to the above-described [DMRS port indication method 1], the terminal can add new rows to [Table 27-1] and [Table 27-2]. ] can create alternatives. If CDM group without data > 1, the newly added column may contain an indication as to which CDM group the RE location corresponding to is not used for data transmission.

As described above, if the values indicated by the column corresponding to Number of DMRS CDM group(s) without data are 1, 2, 3, and 4, respectively, the CDM groups not used for data transmission are {0}, respectively. , {0, 1}, {0, 1, 2}, {0, 1, 2, 3}. This means that the terminal can obtain information that data will not be transmitted to a certain RE location only by indicating the Number of DMRS CDM group(s) without data value, but the CDM group(s) not used for data transmission according to the indicated value. To help support multi-user MIMO, where the location is fixed and requires more flexible scheduling, if a specific Number of DMRS CDM group(s) without data is indicated, it implies that the location of the fixed CDM group(s) is not used for data transmission. Rather than doing so, it may be advantageous to explicitly indicate which CDM group locations are not used for data transmission. If the maximum number of CDM groups for the DMRS type configured by the terminal is N, if Number of DMRS CDM group(s) without data is not 1 or N but a natural number between them (i.e., 2, 3, . .., if N-1), the terminal can create an alternative to [Table 27-1] and [Table 27-2] above, including an additional column indicating the location of the CDM group that is not used for data transmission. . Number of DMRS CDM group(s) without data being 1 means that all CDM groups except one CDM group including the indicated DMRS port can be used for data transmission, and Number of DMRS CDM group(s) without data is 1. Since data is N, it means that all N CDM groups cannot be used for data transmission, so there may be no additional need for location indication of CDM groups that are not used for data transmission.

For example, if the terminal is configured with [Enhanced DMRS type 1 support method 1] and [Enhanced DMRS type 1 support method 2], the terminal may consider the maximum number of CDM groups to be 4, and at this time, [Table 27 above] -1] and [Table 27-2], for entries with Number of DMRS CDM group(s) without data = 2 or 3, entries that consider the location indication information of the CDM group not used for data transmission are additionally considered. You can. In [Table 27-1], for entry 7, Number of DMRS CDM group(s) without data = 2, and the number of the indicated DMRS port(s) is {0,1}, so the existing Number of DMRS CDM group (s) If interpreted to mean without data, CDM groups {0} and {1} are not used for data transmission, but indexes of CDM groups not used for data transmission other than CDM group {0} to which the indicated DMRS ports belong. One of {1}, {2}, and {3} can be defined and indicated as a new column in [Table 27-1]. If the value of Number of DMRS CDM group(s) without data is 2 or 3, except for the CDM group through which the indicated DMRS port is transmitted, the index of the CDM group not used for data transmission is defined as a new column. When using the indicated method, an alternative to [Table 27-1] above can be created as shown in [Table 28-1a] below.

[Table 28-1a] When using [DMRS port indication method 2], maxLength = 1

When maxLength = 1, the [DMRS port indication method 2] can be applied together with at least one of the above [Considerations 1-1] to [Considerations 1-6] and used for DMRS port indication, and accordingly [ Alternatives to [Table 27-1] can be additionally created.

Similar to the creation of [Table 28-1a] above, the [DMRS port indication method 2] is applied together with at least one of the above [Considerations 2-1] to [Considerations 2-6] when maxLength = 2. It can be used to indicate DMRS port, and accordingly, alternatives in [Table 27-2] can be additionally created.

In addition, the [DMRS port indication method 2] does not add a new column as in [Table 28-1a], but uses the existing [Table 27-1] to specify Number of DMRS CDM group without data and DMRS port(s) Indicates, and an additional field in addition to the Antenna port field in the DCI can be used to indicate the index of a CDM group that is not used for data transmission, except for the CDM group in which the DMRS port indicated through the Antenna port field is transmitted.

[DMRS port instruction method 3]

For the above-described [Enhanced DMRS type 1 support method 3], if maxLength = 1, the terminal may be able to indicate DMRS ports 1000 to 1007 using [Table 27-1]. At this time, the terminal has a DMRS RE located in the even-numbered RB where the PDSCH is scheduled when indicated for at least one of DMRS ports 1000 to 1003, and a PDSCH is scheduled when indicated for at least one of DMRS ports 1004 to 1007. The DMRS port indication can be interpreted so that the DMRS RE is located in the odd-numbered RB. As another method, the terminal can indicate the even-numbered RB or odd-numbered RB using an additional column in [Table 25-1] or [Table 25-2]. For example, an alternative to [Table 25-1] above can be created as shown in [Table 29-1a] below.

[Table 29-1a] When using [DMRS port indication method 3], maxLength = 1

In another method, the terminal uses [Table 25-1] or [Table 25-2] above and adds 1 bit to the Antenna port field in the DCI, depending on whether the value of the 1 bit is 0 or 1, respectively. You can be instructed whether to place the DMRS RE in the even-numbered RB or odd-numbered RB where the PDSCH is scheduled.

When maxLength = 1, the [DMRS port indication method 3] can be applied together with at least one of the above [Considerations 1-1] to [Considerations 1-6] and used for DMRS port indication, and accordingly Alternatives to [Table 27-1], [Table 25-1], and [Table 25-2] can be additionally created.

For the above-described [Enhanced DMRS type 1 support method 3], if maxLength = 2, the terminal may be able to indicate DMRS ports 1000 to 1015 using [Table 27-2]. At this time, the terminal has a DMRS RE located in the even-numbered RB where the PDSCH is scheduled when indicated for at least one of DMRS ports 1000 to 1007, and a PDSCH is scheduled when indicated for at least one of DMRS ports 1008 to 1015. The DMRS port indication can be interpreted so that the DMRS RE is located in the odd-numbered RB. As another method, the terminal can indicate the even-numbered RB or odd-numbered RB using an additional column in [Table 25-3] above. In another method, the UE uses [Table 25-3] above and adds 1 bit to the Antenna port field in the DCI to select the even-numbered RBs where the PDSCH is scheduled, respectively, depending on whether the value of the 1 bit is 0 or 1. Alternatively, you can be instructed to place the DMRS RE in the odd-numbered RB.

The terminal is similar to the method of applying [DMRS port indication method 3] to the above-described [enhanced DMRS type 1 support method 3] when maxLength = 1 or 2 for the above-described [enhanced DMRS type 2 support method 2]. By applying this, the DMRS RE corresponding to the indicated DMRS port can be instructed on which position among the RBs where the PDSCH is scheduled.

When maxLength = 2, the [DMRS port indication method 3] can be applied together with at least one of the above [Considerations 2-1] to [Considerations 2-6] and used for DMRS port indication, and accordingly Alternatives to [Table 27-2], [Table 25-3], and [Table 25-4] can be additionally created.

<Example 2-1: Additional DCI-based dynamic indication method for improved DMRS type 1>

As an example of the present disclosure, an additional dynamic indication method based on DCI for improved DMRS type 1 is described.

When the terminal is notified of the upper layer signaling method and the improved DMRS type 1 support method in the first embodiment from the base station, if maxLength, which is the upper layer signaling, is 1, based on the above-described [Table 27-1], In addition to [Considerations 1-1] to [Considerations 1-6], [Considerations 1-7] can be applied to newly or additionally define the variation of [Table 27-1].

[Consideration 1-7] When supporting multi-user MIMO, the terminal receives information about the maximum rank value from the base station, and uses individual DMRS indication tables according to the information (maximum rank value when supporting multi-user MIMO). You can.

■ When supporting multi-user MIMO, the terminal receives the maximum rank value through independent upper layer signaling, sets it through upper layer signaling for supporting the enhanced DMRS types 1 and 2 described above, or sets the maximum rank value through the above-described [Considerations 1-1] to It is set through a combination of at least one of the independent upper layer signaling for [Considerations 1-7], activated or deactivated based on MAC-CE, dynamically indicated through PDCCH, or a value fixedly defined in the standard. can be used.

■ In this way, when supporting multi-user MIMO that can be notified to the terminal, the maximum rank value can be a natural number from 1 to N, and N can be a value from 1 to 8. The terminal may be notified of N by the base station as described above, or the terminal may use the largest of the maximum rank values as the N value when supporting multi-user MIMO, which may be a value fixedly defined in the standard. The terminal is configured through independent upper layer signaling for the N value, or configured through higher layer signaling for supporting the enhanced DMRS types 1 and 2 described above, or configured through [Considerations 1-1] to [Considerations 1-] described above. 7], can be set through a combination of at least one of the independent upper layer signaling, can be activated or deactivated based on MAC-CE, can be dynamically indicated through PDCCH, or can use a value fixedly defined in the standard.

■ The base station and the terminal can define a plurality of DMRS indication tables as many as the N value described above. For example, if the (commonly understood) N value given to the base station and the terminal is 4, the maximum rank value when supporting multi-user MIMO from 1 to N (=4) is considered and the above [Table 27-1] is A total of four modified DMRS indication tables can be defined and used. If these four DMRS indication tables are called [Table 27-1-1] to [Table 27-1-4], then [Table 27-1-1] to [Table 27-1-4] are each multi-user MIMO When supported, it may be a DMRS indication table meaning that the maximum rank value is 1 to 4. That is, [Table 27-1-1] to [Table 27-1-4] are DMRS indication tables that include only entries that can express up to 1 to 4 of the rank values that can be expressed in [Table 27-1], respectively. You can. For example, [Table 27-1-1] is a DMRS indication table that means the maximum rank value is 1 when supporting multi-user MIMO, so among the entries in [Table 27-1], 0, 1, 3, 4, 5, and 6 , 13, 14, 15, 16, 17, 18, 29, 30, 31, 32, 33, 34, 35, and 36 can be defined as a table containing only the entries. As another example, [Table 27-1-2] is a DMRS indication table meaning that the maximum rank value is 2 when supporting multi-user MIMO, so among the entries in [Table 27-1], [Table 27-1-1] [Table 27] Among the entries in -1], the 2nd, 7th, 8, 11, 19, 20, 21, 22, 23, 24, 37, 38, 39, 40, 41, 42, 43, 44, 45, and 46th entries It can be defined as a table containing it. In the same way as defining [Table 27-1-1] and [Table 27-1-2] above, [Table 27-1-3] and [Table 27-1-4] are [Table 27-1] Among the entries, each can be defined as a DMRS indication table including entries with a maximum rank value of 3 and 4.

■ In this way, the base station and the terminal can newly define and use N DMRS indication tables, and if the terminal obtains the maximum rank value when supporting multi-user MIMO as described above, it can use the corresponding DMRS indication table to receive information from the base station. When receiving scheduling information, DMRS-related information decisions can be processed.

When the terminal is notified of the upper layer signaling method and the improved DMRS type 1 support method in the first embodiment from the base station, if maxLength, which is the upper layer signaling, is 1, based on the above-described [Table 27-1], Considering at least one of [Considerations 1-1] to [Considerations 1-7], the alternative (or modification) of [Table 27-1] above is [Table 27-1a] to [Table 27-1f]. ] and [Table 27-1-1] to [Table 27-1-4] (of course, [Table 27-1a] to [Table 27-1f] and [Table 27-1-1] to [Table 27-1-4] is a partial example and may not be limited thereto), if receiving a dynamic indication for enhanced DMRS type 1 from a base station, [Consideration 1-1] to [Consideration 1] above -7], a dynamic indication for the enhanced DMRS type 1 of the base station can be received and processed using the alternative in [Table 27-1], which can be defined by considering at least one of the following.

When the terminal is notified of the upper layer signaling method and the improved DMRS type 1 support method in the first embodiment from the base station, if maxLength, which is the upper layer signaling, is 2, based on the above-described [Table 27-2], In addition to [Considerations 2-1] to [Considerations 2-6], [Considerations 2-7] can be applied to newly or additionally define the variation of [Table 27-2].

[Consideration 2-7] When supporting multi-user MIMO, the terminal receives information about the maximum rank value from the base station, and uses individual DMRS indication tables according to the information (maximum rank value when supporting multi-user MIMO). You can.

■ When supporting multi-user MIMO, the terminal receives the maximum rank value through independent upper layer signaling, sets it through upper layer signaling for supporting the enhanced DMRS types 1 and 2 described above, or sets the maximum rank value through the above-described [Considerations 2-1] to It is set through a combination of at least one of the independent upper layer signaling for [Consideration 2-7], activated or deactivated based on MAC-CE, dynamically indicated through PDCCH, or a value fixedly defined in the standard. can be used.

■ In this way, when supporting multi-user MIMO that can be notified to the terminal, the maximum rank value can be a natural number from 1 to N, and N can be a natural number from 1 to 8. The terminal may be notified of N by the base station as described above, or the terminal may use the largest of the maximum rank values as the N value when supporting multi-user MIMO, which may be a value fixedly defined in the standard. The terminal is configured for the N value through independent upper layer signaling, or configured through upper layer signaling for supporting the enhanced DMRS types 1 and 2 described above, or configured through [Consideration 2-1] to [Consideration 2-] described above. 7], can be set through a combination of at least one of the independent upper layer signaling, can be activated or deactivated based on MAC-CE, can be dynamically indicated through PDCCH, or can use a value fixedly defined in the standard.

■ The base station and the terminal can define a plurality of DMRS indication tables as many as the N value described above. For example, if the (commonly understood) N value given to the base station and the terminal is 4, the maximum rank value when supporting multi-user MIMO from 1 to N (=4) is considered and the above [Table 27-2] A total of four modified DMRS indication tables can be defined and used. If these four DMRS indication tables are referred to as [Table 27-2-1] to [Table 27-2-4], then [Table 27-2-1] to [Table 27-2-4] are each multi-user MIMO When supported, it may be a DMRS indication table meaning that the maximum rank value is 1 to 4. That is, [Table 27-2-1] to [Table 27-2-4] are DMRS indication tables that include only entries that can express up to 1 to 4 of the rank values that can be expressed in [Table 27-2], respectively. You can. For example, [Table 27-2-1] is a DMRS indication table that means the maximum rank value is 1 when supporting multi-user MIMO, so among the entries in [Table 27-2], 0, 1, 3 ~ 6, 13 ~ 18 , can be defined as a table containing only the 29th to 36th, 51st to 67th, 85th to 98th, and 103rd to 114th entries. In the same way as defining [Table 27-2-1] above, [Table 27-2-2], [Table 27-2-3], and [Table 27-2-4] are [Table 27-2] Among the entries, each can be defined as a DMRS indication table including entries with maximum rank values of 2, 3, and 4.

■ In this way, the base station and the terminal can newly define and use N DMRS indication tables, and if the terminal obtains the maximum rank value when supporting multi-user MIMO as described above, it can use the corresponding DMRS indication table to receive information from the base station. When receiving scheduling information, DMRS-related information decisions can be processed.

When the terminal is notified of the upper layer signaling method and the improved DMRS type 1 support method in the first embodiment from the base station, if maxLength, which is the upper layer signaling, is 2, based on the above-described [Table 27-2], Considering at least one of [Considerations 2-1] to [Considerations 2-7], an alternative (or modification) of [Table 27-2] is listed in [Table 27-2a] to [Table 27-2e]. ] and [Table 27-2-1] to [Table 27-2-4] (of course, [Table 27-2a] to [Table 27-2e] and [Table 27-2-1] to [Table 27-2-4] is a partial example and may not be limited thereto), if receiving a dynamic indication for enhanced DMRS type 1 from a base station, [Consideration 2-1] to [Consideration 2] above -7], a dynamic indication for the enhanced DMRS type 1 of the base station can be received and processed using the alternative in [Table 27-2], which can be defined by considering at least one of the following.

[DMRS port instruction method 4]

If the terminal receives [Enhanced DMRS type 1 support method 4] or [Enhanced DMRS type 1 support method 6], the terminal instructs the DMRS port based on [Table 30-1] and [Table 30-2] below. can be performed. [Table 30-1] and [Table 30-2] are DMRS port indication tables that can be used when maxLength = 1 and 2, respectively, and maxLength can mean the maximum number of front-loaded symbols.

[Table 30-1] When using [DMRS port indication method 4], maxLength = 1

The above [Table 30-1] is applicable to [Enhanced DMRS type 1 support method 4] to [Enhanced DMRS type 1 support method 6] using two CDM groups, and [Table 26-1-2] to [Table 26-1-2] to [Table 26-1-2]. Based on [26-1-4], when using one front-loaded DMRS symbol, the numbers of DMRS ports included in the first CDM group are 0, 1, 8, and 9, and the DMRS ports included in the second CDM group are The number may be 2, 3, 10, or 11. In the case where entries 0 to 3 of [Table 30-1] use only one DMRS port out of a total of four DMRS ports in the first CDM group, entries 4 to 9 use two DMRS ports out of a total of four DMRS ports. When using, entries 10 to 14 may mean using 3 DMRS ports out of a total of 4 DMRS ports, and entry 15 may mean using 4 DMRS ports. Likewise, entries 15 to 22 use only 1 DMRS port out of a total of 8 DMRS ports in the two CDM groups, and entries 23 to 50 include a total of 28 cases, and a total of 8 cases in the two CDM groups. When using two DMRS ports among DMRS ports, entries 51 to 106 include a total of 56 cases, and when using three DMRS ports out of a total of eight DMRS ports in two CDM groups, entry 107 Numbers through 176 include a total of 70 cases, and may mean cases of using 4 DMRS ports out of a total of 8 DMRS ports in two CDM groups. This shows the number of cases for combinations of all DMRS ports that can indicate ranks 1 to 4 in the case where maxLength, which is upper layer signaling, is set to 1. [Table 30-1] shows a total of 177 entries as described above. It may be expressed in 8 bits that can indicate, and when considering various alternatives in [Table 30-1] by considering at least one of the above-mentioned [Considerations 1-1] to [Considerations 1-7] It may also be expressed as a number of bits less or more than the 8 bits that can be used to express [Table 30-1]. The numbers 0, 1, 8, and 9 of the DMRS ports included in the above-mentioned first CDM group and the numbers 2, 3, 10, and 11 of the DMRS ports included in the second CDM group are only examples, and other DMRS Configuring a DMRS indication table using port numbers may also not be ruled out (for example, DMRS ports 0 to 3 in the first CDM group, DMRS ports 4 to 7 in the second CDM group, or DMRS ports in the first CDM group). 0, 1, 4, 5, DMRS ports 2, 3, 6, 7 in the second CDM group).

[Table 30-2] When using [DMRS port indication method 4], maxLength = 2

The above [Table 30-2] is applicable to [Enhanced DMRS type 1 support method 4] to [Enhanced DMRS type 1 support method 6] using two CDM groups, and [Table 26-1-2] to [Table 26-1-2] to [Table 26-1-2]. Based on [26-1-4], when two front-loaded DMRS symbols are used, the numbers of DMRS ports included in the first CDM group are 0, 1, 4, 5, 8, 9, 12, and 13. The numbers of DMRS ports included in the th CDM group may be 2, 3, 6, 7, 10, 11, 14, and 15. Entries 0 to 176 of [Table 30-2] may be the same as the entries of [Table 30-1] since one front-loaded DMRS symbol is used. Entries 177 to 338 of [Table 30-2] use two front-loaded DMRS symbols and the value of Number of DMRS CDM group(s) without data is 1, so a total of 8 DMRS in the first CDM group This shows the case of using 1 to 4 DMRS ports among the ports, and entries 339 to 2854 use 2 front-loaded DMRS symbols and the value of Number of DMRS CDM group(s) without data is 2. , This may mean using 1 to 4 DMRS ports out of a total of 16 DMRS ports in the first and second CDM groups. This shows the number of cases for combinations of all DMRS ports that can indicate ranks 1 to 4 in the case where maxLength, which is upper layer signaling, is set to 2. [Table 30-2] shows a total of 2854 entries as described above. It may be expressed as 12 bits that can indicate, and when considering various alternatives in [Table 30-2] by considering at least one of the above-mentioned [Considerations 2-1] to [Considerations 2-7] It may also be expressed as a number of bits less or more than the 12 bits that can be used to express [Table 30-2]. The numbers of DMRS ports included in the first CDM group described above are 0, 1, 4, 5, 8, 9, 12, 13, and the numbers of DMRS ports included in the second CDM group are 2, 3, 6, 7, 10, 11, 14, and 15 are just one example, and configuring a DMRS indication table using other DMRS port numbers may not be ruled out (for example, DMRS ports 0 to 7 in the first CDM group, and DMRS ports 0 to 7 in the second CDM group). DMRS ports 8 to 15 in the group, or DMRS ports 0, 1, 2, 3, 8, 9, 10, 11 in the first CDM group, or DMRS ports 4, 5, 6, 7, 12, and 13 in the second CDM group. , 14, 15).

As described above, [DMRS port indication method 1] is applicable when [Enhanced DMRS type 1 support method 1] or [Enhanced DMRS type 1 support method 2] has been set, but in addition to this, [Enhanced DMRS type 1 support method 1] It may also be applicable to other support methods for improved DMRS type 1, such as [Method 3] to [Improved DMRS type 1 support method 6]. Similarly, [DMRS port indication method 2] to [DMRS port indication method 4] may be applicable to both [Enhanced DMRS type 1 support method 1] to [Enhanced DMRS type 1 support method 6]. At this time, the DMRS indication table can be configured by applying a combination of at least one of the considerations for each DMRS port indication method. The base station and the terminal use at least one newly configured DMRS indication table for improved DMRS type 1 or 2 to estimate the channel by using information such as the location, OCC value, and transmission power of the DMRS port and RE transmitted together during PDSCH scheduling. Can be used for

<Example 2-2: DCI-based dynamic indication method for improved DMRS type 2>

As an example of the present disclosure, a DCI-based DMRS port indication method for the above-described enhanced DMRS type 2 is described. The terminal can receive an indication about the DMRS port allocated during PDSCH scheduling from the base station through DCI format 1_1 or DCI format 1_2. As described above, DMRS port indication based on existing DMRS types 1 and 2 is possible through the Antenna port field in DCI format 1_1 and DCI format 1_2 using one of [Table 25-1] to [Table 25-8]. did.

When the terminal receives a DCI-based DMRS port indication for enhanced DMRS type 2 from the base station, it can expect to support up to one codeword. That is, the terminal can expect n1 to be set for maxNrofCodeWordsScheduledByDCI, which is upper layer signaling, from the base station.

Regarding various methods of supporting the improved DMRS type 2 defined in the above-described first embodiment, the methods indicated through the Antenna port field in DCI format 1_1 and DCI format 1_2 will be described in detail.

[DMRS port instruction method 5]

If the terminal receives [Enhanced DMRS type 2 support method 1] or [Enhanced DMRS type 2 support method 3], the terminal instructs the DMRS port based on [Table 31-1] and [Table 31-2] below. can be performed. [Table 31-1] and [Table 31-2] are DMRS port indication tables that can be used when maxLength = 1 and 2, respectively, and maxLength can mean the maximum number of front-loaded symbols.

[Table 31-1] When using [DMRS port indication method 5], maxLength = 1

The above [Table 31-1] is applicable to [Enhanced DMRS type 2 support method 1] to [Enhanced DMRS type 2 support method 3] using three CDM groups, and based on [Table 26-8], one When using the front-loaded DMRS symbol, the numbers of DMRS ports included in the first CDM group are 0, 1, 2, and 3, and the numbers of DMRS ports included in the second CDM group are 4, 5, 6, and 7. , the numbers of DMRS ports included in the third CDM group may be 8, 9, 10, or 11. Since entries 0 to 14 of [Table 31-1] have the value of Number of DMRS CDM group(s) without data being 1, 1 to 4 DMRS ports out of a total of 4 DMRS ports in the first CDM group This shows the case of using, and entries 15 to 176 are cases where the value of Number of DMRS CDM group(s) without data is 2, so 1 to 4 of a total of 8 DMRS ports in the first and second CDM groups. This shows the case of using DMRS ports, and entries 177 to 969 are cases where the value of Number of DMRS CDM group(s) without data is 3, so 1 of a total of 12 DMRS ports in the first to third CDM group(s). This shows a case where one to four DMRS ports are used. This shows the number of cases for combinations of all DMRS ports that can indicate ranks 1 to 4 in the case where maxLength, which is upper layer signaling, is set to 1. [Table 31-1] shows a total of 969 entries as described above. It may be expressed as 10 bits that can indicate, and when considering various alternatives in [Table 31-1] by considering at least one of the above-mentioned [Considerations 1-1] to [Considerations 1-7] It may also be expressed as a number of bits less or more than the 10 bits that can be used to express [Table 31-1]. DMRS port numbers 0, 1, 2, 3 included in the above-mentioned first CDM group, DMRS port numbers 4, 5, 6, 7 included in the second CDM group, and DMRS included in the third CDM group. The port numbers 8, 9, 10, and 11 are just one example, and configuring a DMRS indication table using other DMRS port numbers may not be ruled out (for example, DMRS ports 0 and 1 in the first CDM group). , 6, 7, DMRS ports 2, 3, 8, 9 in the second CDM group, DMRS ports 4, 5, 10, 11 in the third CDM group).

[Table 31-2] When using [DMRS port indication method 5], maxLength = 2

The above [Table 31-2] is applicable to [Enhanced DMRS type 2 support method 1] to [Enhanced DMRS type 2 support method 3] using three CDM groups, and based on [Table 26-8], one When using the front-loaded DMRS symbol, the numbers of DMRS ports included in the first CDM group are 0, 1, 2, and 3, and the numbers of DMRS ports included in the second CDM group are 4, 5, 6, and 7. , the numbers of DMRS ports included in the third CDM group can be 8, 9, 10, 11, and when two front-loaded DMRS symbols are used, the numbers of DMRS ports included in the first CDM group are 0, 1. , 2, 3, 12, 13, 14, 15, and the DMRS port numbers included in the second CDM group are 4, 5, 6, 7, 16, 17, 18, 19, and the numbers included in the third CDM group are The DMRS port numbers may be 8, 9, 10, 11, 20, 21, 22, 23. Since entries 0 to 969 of [Table 31-2] use one front-loaded DMRS symbol, they may be the same as the entries of [Table 31-1]. Entries 970 to 1131 of [Table 30-2] use two front-loaded DMRS symbols and the value of Number of DMRS CDM group(s) without data is 1, so a total of 8 DMRS in the first CDM group This shows the case of using 1 to 4 DMRS ports among the ports, and entries 1132 to 3651 use 2 front-loaded DMRS symbols and the value of Number of DMRS CDM group(s) without data is 2. , This may mean using 1 to 4 DMRS ports out of a total of 16 DMRS ports in the first and second CDM groups, and entries 3652 to 16601 use two front-loaded DMRS symbols and Number of Since the value of DMRS CDM group(s) without data is 3, this may mean using 1 to 4 DMRS ports out of a total of 24 DMRS ports in the first to third CDM group. This shows the number of cases for combinations of all DMRS ports that can indicate ranks 1 to 4 in the case where maxLength, which is upper layer signaling, is set to 2. [Table 31-2] shows a total of 16601 entries as described above. It may be expressed as 14 bits that can indicate, and when considering various alternatives in [Table 31-2] by considering at least one of the above-mentioned [Considerations 2-1] to [Considerations 2-7] It may also be expressed as a number of bits less or more than the 14 bits that can be used to express [Table 31-2]. The numbers of DMRS ports included in the first CDM group described above are 0, 1, 2, 3, 12, 13, 14, 15, and the numbers of DMRS ports included in the second CDM group are 4, 5, 6, 7, 16, 17, 18, 19 and the DMRS port numbers 8, 9, 10, 11, 20, 21, 22 and 23 included in the third CDM group are just examples, and the DMRS indication table using other DMRS port numbers Configuring may also not be ruled out (for example, DMRS ports 0, 1, 6, 7, 12, 13, 18, 19 in the first CDM group, DMRS ports 2, 3, 8, 9 in the second CDM group) , 14, 15, 20, 21, DMRS ports 4, 5, 10, 11, 16, 17, 22, 23 in the third CDM group)

[DMRS port instruction method 6]

If the terminal is configured with [Enhanced DMRS type 2 support method 4], the terminal can perform DMRS port instructions based on [Table 32-1] and [Table 32-2] below. [Table 32-1] and [Table 32-2] are DMRS port indication tables that can be used when maxLength = 1 and 2, respectively, and maxLength can mean the maximum number of front-loaded symbols.

[Table 32-1] When using [DMRS port indication method 6], maxLength = 1

[Table 32-1] above is applicable to [Enhanced DMRS type 2 support method 4] using 6 CDM groups, and based on [Table 26-2-4], using 1 front-loaded DMRS symbol. In this case, the numbers of DMRS ports included in the first CDM group are 0 and 1, the numbers of DMRS ports included in the second CDM group are 2 and 3, and the numbers of DMRS ports included in the third CDM group are 4 and 5. The numbers of DMRS ports included in the fourth CDM group are 12 and 13, the numbers of DMRS ports included in the fifth CDM group are 14 and 15, and the numbers of DMRS ports included in the sixth CDM group are 16. It could be 17. Since entries 0 to 2 of [Table 32-1] have the value of Number of DMRS CDM group(s) without data being 1, one to two DMRS ports out of a total of two DMRS ports in the first CDM group This shows the case of using, and entries 3 to 17 are cases where the value of Number of DMRS CDM group(s) without data is 2, so 1 to 4 of a total of 4 DMRS ports in the first and second CDM group This shows the case of using DMRS ports, and subsequent entries may also indicate that the value of Number of DMRS CDM group(s) without data is 3 to 6. This shows the number of cases for combinations of all DMRS ports that can indicate ranks 1 to 4 in the case where maxLength, which is upper layer signaling, is set to 1. [Table 32-1] shows a total of 1403 entries as described above. It may be expressed as 11 bits that can indicate, and when considering various alternatives in [Table 32-1] by considering at least one of the above-mentioned [Considerations 1-1] to [Considerations 1-7] It may also be expressed as a number of bits less or more than the 11 bits that can be used to express [Table 32-1]. 0, 1, which are the numbers of DMRS ports included in the above-mentioned first CDM group, 2, 3, which are the numbers of DMRS ports included in the second CDM group, 4, 5, which are the numbers of DMRS ports included in the third CDM group, The DMRS port numbers 12 and 13 included in the fourth CDM group, the DMRS port numbers 14 and 15 included in the fifth CDM group, and the DMRS port numbers 16 and 17 included in the fourth CDM group are one This is only an example, and configuring a DMRS indication table using other DMRS port numbers may not be ruled out (e.g., DMRS ports 0 and 1 in the first CDM group, and DMRS ports 2, 3, and 3 in the second CDM group). DMRS ports 4 and 5 in the CDM group, DMRS ports 6 and 7 in the fourth CDM group, DMRS ports 8 and 9 in the fifth CDM group, and DMRS ports 10 and 11 in the sixth CDM group.

[Table 32-2] When using [DMRS port indication method 6], maxLength = 2

[Table 32-2] above is applicable to [Enhanced DMRS type 2 support method 4] using 6 CDM groups, and based on [Table 26-2-4], using 1 front-loaded DMRS symbol. In this case, the numbers of DMRS ports included in the first CDM group are 0 and 1, the numbers of DMRS ports included in the second CDM group are 2 and 3, and the numbers of DMRS ports included in the third CDM group are 4 and 5. The numbers of DMRS ports included in the fourth CDM group are 12 and 13, the numbers of DMRS ports included in the fifth CDM group are 14 and 15, and the numbers of DMRS ports included in the sixth CDM group are 16. It can be 17, and when two front-loaded DMRS symbols are used, the numbers of DMRS ports included in the first CDM group are 0, 1, 6, and 7, and the numbers of DMRS ports included in the second CDM group are 2. , 3, 8, 9, and the numbers of DMRS ports included in the third CDM group are 4, 5, 10, 11, and the numbers of DMRS ports included in the fourth CDM group are 12, 13, 18, 19, The numbers of DMRS ports included in the fifth CDM group may be 14, 15, 20, and 21, and the numbers of DMRS ports included in the sixth CDM group may be 16, 17, 22, and 23. [Table 32-2] shows the number of cases for combinations of all DMRS ports that can indicate ranks 1 to 4 when maxLength, which is upper layer signaling, is set to 2. As described above, it may be expressed in 14 bits that can indicate a total of 11088 entries, and considering at least one of the above-mentioned [Considerations 2-1] to [Considerations 2-7] [Table 32-2] When considering various alternatives, it may be expressed with a number of bits less or more than the 14 bits that can be used to express [Table 32-2]. 0, 1, 6, 7, which are the numbers of DMRS ports included in the above-mentioned first CDM group; 2, 3, 8, 9, which are the numbers of DMRS ports included in the second CDM group; and DMRSs included in the third CDM group. Port numbers 4, 5, 10, 11, DMRS port numbers included in the fourth CDM group 12, 13, 18, 19, DMRS port numbers included in the fifth CDM group 14, 15, 20, 21, the numbers 16, 17, 22, and 23 of the DMRS ports included in the fourth CDM group are only examples, and configuring a DMRS indication table using other DMRS port numbers may not be ruled out (for example, DMRS ports 0 to 3 in the first CDM group, DMRS ports 4 to 7 in the second CDM group, DMRS ports 8 to 11 in the third CDM group, DMRS ports 12 to 15 in the fourth CDM group, DMRS in the fifth CDM group Ports 16 to 19, DMRS ports 20 to 23 in the sixth CDM group).

As described above, [DMRS port indication method 5] is applicable to cases where [Improved DMRS type 2 support method 1] to [Improved DMRS type 2 support method 3] are set, but in addition, [Improved DMRS type 2 support method 3] is applicable. It may also be applicable to other support methods for improved DMRS type 2, such as [Method 4]. Similarly, [DMRS port indication method 6] may be applicable to both [Enhanced DMRS type 2 support method 1] to [Enhanced DMRS type 2 support method 4]. At this time, the DMRS indication table can be configured by applying a combination of at least one of the considerations for each DMRS port indication method. The base station and the terminal use at least one newly configured DMRS indication table for improved DMRS type 2 to use information such as location, OCC value, and transmission power for the DMRS port and RE transmitted together during PDSCH scheduling when estimating the channel. You can.

<Third embodiment: DCI-based dynamic indication method for improved DMRS types 1 and 2 during uplink data transmission>

According to an embodiment of the present disclosure, a DCI-based dynamic indication method for improved DMRS types 1 and 2 when transmitting uplink data (PUSCH) is described. The terminal can receive an indication about the DMRS port allocated during PUSCH scheduling from the base station through DCI format 0_1 or DCI format 0_2. As described above, DMRS port indication based on existing DMRS types 1 and 2 is possible through the antenna port fields in DCI format 0_1 and DCI format 0_2 using one of [Table 25-9] to [Table 25-24]. did.

When the terminal receives a DCI-based DMRS port indication for advanced DMRS types 1 and 2 from the base station, it can be expected to support up to one codeword. That is, the terminal can expect n1 to be set for higher layer signaling (eg, maxNrofCodeWordsForPUSCHScheduledByDCI) from the base station.

Regarding the various methods of supporting the improved DMRS types 1 and 2 defined in the above-described first embodiment, the methods indicated through the Antenna port field in DCI format 0_1 and DCI format 0_2 will be described in detail.

The terminal uses one of the above-described [Higher Setting Method 1], [Higher Setting Method 1-1], [Higher Setting Method 1-2], or [Higher Setting Method 2] for the enhanced DMRS type 1 or 2 to be applied to PDSCH reception. It can be similarly applied to enhanced DMRS type 1 or 2 to be applied to PUSCH transmission scheduled in DCI format 0_1 and 0_2 using at least one combination. For example, if the UE similarly applies the above-described [Higher Setting Method 1] to PUSCH transmission, the UE can be configured to support the enhanced DMRS type within DMRS-UplinkConfig, which is higher layer signaling.

For PUSCH transmission scheduled in DCI format 0_1 and 0_2, the terminal uses the above-described [Enhanced DMRS type 1 support method 1] to [Enhanced DMRS type 1 support method 6] and [Enhanced DMRS type 2 support method 1] to [Enhanced DMRS support method]. [type 2 support method 4] can be used similarly to the method applied to PDSCH DMRS to receive and understand instructions for one or multiple DMRS ports based on improved DMRS type 1 or 2 applied when transmitting PUSCH from the base station. there is. Similarly, the terminal uses the above-described [DMRS port indication method 1] to [DMRS port indication method 6] and the corresponding above-mentioned [Consideration 1-1] to [Consideration 1-7] or [Consideration 2- 1] to [Considerations 2-7], applying a combination of at least one or more of them, and using a method similar to that applied to PDSCH DMRS, one based on improved DMRS type 1 or 2 applied when transmitting PUSCH from the base station. Alternatively, instructions for multiple DMRS ports can be received and understood. The difference between [DMRS port indication method 1] to [DMRS port indication method 6] that can be used in the PDSCH DMRS port indication and when applying it to the PUSCH DMRS port indication is that in the case of the PDSCH DMRS port indication, there is one DMRS indication table. If all these rank values (for example, 1 to 4) are included, the same upper layer setting value (for example, maxLength is set to 1) as in [Table 25-9] to [Table 25-12] in the case of PUSCH DMRS port indication ), it may be that different DMRS indication tables are used according to different rank values. As an example, if the base station and the terminal wish to use the above-described [Table 27-1a] as a DMRS indication table to be applied to PUSCH transmission, each rank value as shown in [Table 33-1] to [Table 33-4] as follows. It can be defined separately. At this time, in the case of codebook-based PUSCH transmission within DCI format 0_1 or 0_2 (when txConfig, which is upper layer signaling, is set to codebook and the usage of SRS resource set is set to codebook), Precoding information and number of layers fields, In the case of noncodebook-based PUSCH transmission (when txConfig, which is upper layer signaling, is set to noncodebook and usage of SRS resource set is set to noncodebook), the base station based on the DMRS indication table corresponding to the rank value known through the SRI field You can understand the DMRS port indication information from . For example, if the rank value known through the Precoding information and number of layers field or the SRI field is 2, the base station establishes a DMRS port based on a DMRS indication table with a rank value of 2 (for example, [Table 33-2]). The indication can be notified to the terminal, and the terminal can also receive a DMRS port indication from the base station based on a DMRS indication table with a rank value of 2 and understand the indicated DMRS port numbers. In addition, as described above, rank information can be known through the Precoding information and number of layers field or the SRI field, so the Antenna port field does not need to separately indicate rank information, so the bit length of the Antenna port field is set to a specific upper layer signaling setting. (For example, in the case of enhanced DMRS type 1 and maxLength set to 1, as in the case of [Table 33-1] to [Table 33-4]), the number of bits that can represent the largest number of entries among the entries corresponding to each rank value is It may be necessary. For example, [Table 33-1] and [Table 33-2] have 20 entries, [Table 33-3] has 6 entries, and [Table 33-4] has 5 entries, so the most Five bits may be needed to represent 20, the number of entries.

[Table 33-1] Example of alternatives applied to [DMRS port instruction method 1] and [Consideration 1-1], maxLength = 1, rank=1

[Table 33-2] An example of the alternatives used in [DMRS port instruction method 1] and [Considerations 1-1], maxLength = 1, rank=2

[Table 33-3] Example of alternatives applied to [DMRS port instruction method 1] and [Consideration 1-1], maxLength = 1, rank=3

[Table 33-4] Example of alternatives applied to [DMRS port instruction method 1] and [Considerations 1-1], maxLength = 1, rank=4

All methods in this embodiment can be equally applied to configuration grant type 1 based on upper layer signaling or configuration grant type 2 activated by DCI format 0_0, 0_1, or 0_2. At this time, in order to apply all methods in this embodiment to configuration grant type 1 or 2, the terminal is based on upper layer signaling independent from the base station, or based on upper layer signaling for supporting the enhanced DMRS types 1 and 2 described above. Alternatively, it can be activated or deactivated based on MAC-CE, dynamically indicated through PDCCH, or defined in the standard.

Figure 24 is a diagram showing the operation of a terminal to support improved DMRS types 1 and 2 according to an embodiment of the present disclosure.

The terminal can report its capabilities to the base station (24-00). At this time, the terminal capability that can be reported may be the terminal capability of supporting enhanced DMRS types 1 and 2 as described above, and may be the terminal capability of whether or not each method mentioned in the above embodiments is supported, PDSCH and PUSCH may have individual terminal capabilities or may have integrated terminal capabilities. Afterwards, the terminal can receive information about improved DMRS type 1 or 2 from the base station (24-01). At this time, information about improved DMRS type 1 or 2 is sent from the base station to the terminal for each of the methods mentioned in the above embodiments (based on independent upper layer signaling or for supporting the improved DMRS types 1 and 2 described above). may be based on upper layer signaling, may be activated or deactivated based on MAC-CE, or may be dynamically indicated through PDCCH). Afterwards, the terminal can receive PDSCH or PUSCH scheduling information to which improved DMRS type 1 or 2 is applied from the base station (24-02). At this time, the corresponding scheduling information may be indicated through DCI format 0_1 or 0_2 in the case of PUSCH, and may be indicated through DCI format 1_1 or 1_2 in the case of PDSCH, and the information indicated through the Antenna port field in each DCI format is 1, which can be defined through a combination of at least one of the [DMRS port indication method 1] to [DMRS port indication method 6] according to the method obtained in the step of receiving information about the improved DMRS type 1 or 2 described above. It can be based on one or more DMRS indication tables. Based on the corresponding scheduling information, the terminal can receive a PDSCH to which improved DMRS type 1 or 2 is applied or transmit a PUSCH (24-03).

Figure 25 is a diagram showing the operation of a base station to support improved DMRS types 1 and 2 according to an embodiment of the present disclosure.

The base station can receive terminal capabilities from the terminal (25-00). Afterwards, the base station can transmit information about improved DMRS type 1 or 2 to the terminal (25-01). At this time, information about improved DMRS type 1 or 2 is sent from the base station to the terminal for each of the methods mentioned in the above embodiments (based on independent upper layer signaling or for supporting the improved DMRS types 1 and 2 described above). may be based on upper layer signaling, may be activated or deactivated based on MAC-CE, or may be dynamically indicated through PDCCH). Afterwards, the base station can transmit PDSCH or PUSCH scheduling information to which improved DMRS type 1 or 2 is applied to the terminal (25-02). At this time, the corresponding scheduling information may be indicated through DCI format 0_1 or 0_2 in the case of PUSCH, and may be indicated through DCI format 1_1 or 1_2 in the case of PDSCH, and the information indicated through the Antenna port field in each DCI format is 1, which can be defined through a combination of at least one of the [DMRS port indication method 1] to [DMRS port indication method 6] according to the method obtained in the step of receiving information about the improved DMRS type 1 or 2 described above. It can be based on one or more DMRS indication tables. Based on the scheduling information, the base station can transmit a PDSCH to which improved DMRS type 1 or 2 is applied or receive a PUSCH (25-03).

<Fourth Embodiment: Sequence initialization method when simultaneously supporting enhanced DMRS types 1 and 2 and low PAPR DMRS>

As an example of the present disclosure, a method of initializing a promised DMRS sequence of a base station and a terminal when simultaneously supporting enhanced DMRS types 1 and 2 and low PAPR DMRS is described.

The terminal can use [Equation 7] below to initialize the pseudo random sequence generator used to generate the PDSCH DMRS sequence.

[Equation 7]

Each parameter in Equation 7 may have the following meaning.

■ means the OFDM symbol number in the slot, may mean a slot number within the frame.

■ , : It may be a value corresponding to scramblingID0 and scramblingID1, which are upper layer signaling, respectively set in DMRS-DownlinkConfig, which is upper layer signaling. This value can be used when the PDSCH is scheduled in DCI format 1_1 or 1_2, and the CRC of the PDCCH is scrambled by C-RNTI, MCS-C-RNTI, or CS-RNTI.

■ : This may be a value corresponding to scramblingID0, which is upper layer signaling, set in DMRS-DownlinkConfig, which is upper layer signaling. This value can be used when the PDSCH is scheduled in DCI format 1_0, and the CRC of the PDCCH is scrambled with C-RNTI, MCS-C-RNTI, or CS-RNTI.

■ , : Within the common MBS (multicast broadcast signal) frequency resource for multicast, it may be a value corresponding to scramblingID0 and scramblingID1, which are upper layer signaling, respectively, set in DMRS-DownlinkConfig, which is upper layer signaling. This value can be used when the PDSCH is scheduled in DCI format 4_2 and the CRC of the PDCCH is scrambled with G-RNTI or G-CS-RNTI.

■ : Within common MBS (multicast broadcast signal) frequency resources for multicast, it may be a value corresponding to scramblingID0, which is upper layer signaling, set in DMRS-DownlinkConfig, which is upper layer signaling. This value can be used when the PDSCH is scheduled as a PDCCH and the CRC of the PDCCH is scrambled as a G-RNTI, G-CS-RNTI, or MCCH-RNTI.

■ If none of the above applies, Is It can be used as a (cell ID) value.

■ and can be interpreted as follows.

- If dmrs-Downlink is set in DMRS-DownlinkConfig, which is upper layer signaling,

,

( may mean CDM group number)

- If not,

■ A value of 0 or 1 may be indicated to the UE through the DMRS sequence initialization field that may exist in the DCI that schedules the PDSCH. At this time, the possible DCI formats may be 1_1, 1_2, and 4_2, otherwise, am.

The terminal can use [Equation 8] below to initialize the pseudo random sequence generator used to generate the PUSCH DMRS sequence.

[Equation 8]

Each parameter in Equation 8 may have the following meaning.

■ means the OFDM symbol number in the slot, may mean a slot number within the frame.

■ , : May be values corresponding to scramblingID0 and scramblingID1, which are upper layer signaling, respectively, set in DMRS-UplinkConfig, which is upper layer signaling. This value can be used when PUSCH is scheduled in DCI format 0_1 or 0_2 or transmitted based on a configuration grant.

■ : This may be a value corresponding to scramblingID0, which is upper layer signaling, set in DMRS-UplinkConfig, which is upper layer signaling. This value can be used when the PUSCH is scheduled in DCI format 0_0, and the CRC of the PDCCH is scrambled with C-RNTI, MCS-C-RNTI, or CS-RNTI.

■ , : For each msgA PUSCH setting, it may be a value corresponding to msgA-ScramblingID0 and msgA-ScramblingID1 set in msgA-DMRS-Config, which is upper layer signaling. This value can be used when PUSCH is triggered through a Type 2 random access process.

■ If none of the above applies, Is It can be used as a (cell ID) value.

■ and can be interpreted as follows.

- If dmrs-Uplink is set in DMRS-UplinkConfig, which is upper layer signaling,

,

( may mean CDM group number)

- If not,

■ may be indicated, set or determined as follows:

- A value of 0 or 1 may be indicated to the UE through the DMRS sequence initialization field that may exist in the DCI that schedules the PUSCH. At this time, possible DCI formats may include 0_1 and 0_2.

- When PUSCH is transmitted through configuration grant Type 1, it can be configured through dmrs-SeqInitialization, which is upper layer signaling.

- When PUSCH is transmitted through a Type 2 random access process, it can be determined through mapping between the preamble, PUSCH transmission location, and connected DMRS resources.

- When a configuration grant-based PUSCH is transmitted in the RRC inactive state, it can be determined through mapping between the SSB, the PUSCH transmission location, and the connected DMRS resource.

- If none of the above applies am.

If the terminal supports the above-described enhanced DMRS type 1 or 2 (for example, the above-described [Enhanced DMRS type 1 support method 1] to [Enhanced DMRS type 1 support method 6] or [Enhanced DMRS type 2 support method 1] to [Method based on a combination of at least one of [Enhanced DMRS type 2 support method 4]), that is, when information to support enhanced DMRS type 1 or 2 is notified from the base station based on upper layer signaling or L1 signaling, enhanced DMRS Whether type 1 or 2 and low PAPR DMRS sequences can be used simultaneously can be reported to the base station as a terminal capability. The UE capabilities may be reported as independent UE capabilities for each PDSCH and PUSCH, or as one UE capability integrated to support PDSCH and PUSCH.

The terminal is configured through independent upper layer signaling for a low PAPR DMRS sequence that can be used simultaneously with enhanced DMRS type 1 or 2, or configured through higher layer signaling for supporting enhanced DMRS types 1 and 2 described above, or as described above. It is set through a combination of at least one of independent upper layer signaling for [Consideration 1-1] to [Consideration 1-7] or [Consideration 2-1] to [Consideration 2-7], or It can be activated or deactivated based on MAC-CE, or can be dynamically instructed through PDCCH. As another method, if the terminal supports enhanced DMRS type 1 or 2, (for example, [Enhanced DMRS type 1 support method 1] to [Enhanced DMRS type 1 support method 6] or [Enhanced DMRS type 2 support described above) [Method 1] to [Method based on a combination of at least one of [Enhanced DMRS type 2 support method 4]), that is, information to support enhanced DMRS type 1 or 2 is notified from the base station based on upper layer signaling or L1 signaling In this case, the terminal may need to assume that the low PAPR DMRS sequence can be used. Alternatively, if the terminal supports enhanced DMRS type 1 or 2, (for example, the above-described [Enhanced DMRS type 1 support method 1] to [Enhanced DMRS type 1 support method 6] or [Enhanced DMRS type 2 support [Method 1] to [Method based on a combination of at least one of [Enhanced DMRS type 2 support method 4]), that is, information to support enhanced DMRS type 1 or 2 is notified from the base station based on upper layer signaling or L1 signaling In this case, the terminal may have to assume that the low PAPR DMRS sequence cannot be used.

If the terminal supports enhanced DMRS type 1 or 2, (for example, the above-described [Enhanced DMRS type 1 support method 1] to [Enhanced DMRS type 1 support method 6] or [Enhanced DMRS type 2 support method 1] to [ Method based on a combination of at least one of [Enhanced DMRS type 2 support method 4]), that is, when information to support enhanced DMRS type 1 or 2 is notified from the base station based on upper layer signaling or L1 signaling, and can be interpreted as follows.

, ( may mean CDM group number)

Another way: and can be interpreted as follows.

, ( may mean CDM group number)

FIG. 22 is a diagram illustrating the structure of a terminal in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 22, the terminal may include a transceiver (referring to a terminal receiver 2200 and a terminal transmitter 2210), a memory (not shown), and a terminal processing unit 2205 (or a terminal control unit or processor). Depending on the communication method of the terminal described above, the terminal's transceiver units (2200, 2210), memory, and terminal processing unit (2205) can 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 aforementioned components. In addition, the transceiver, memory, and processor may be implemented in the form of a single chip.

The transceiver unit can transmit and receive signals to and from the base station. Here, the signal may include control information and data. To this end, the transceiver may be composed of an RF transmitter that up-converts and amplifies the frequency of the transmitted signal, and an RF receiver that amplifies the received signal with low noise and down-converts the frequency. However, this is only an example of the transceiver, and the components of the transceiver are not limited to the RF transmitter and RF receiver.

Additionally, the transceiver may receive a signal through a wireless channel and output it to the processor, and transmit the signal output from the processor through a wireless channel.

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

Additionally, the processor can control a series of processes so that the terminal can operate according to the above-described embodiment. For example, the processor can receive a DCI composed of two layers and control the components of the terminal to receive multiple PDSCHs at the same time. There may be a plurality of processors, and the processor may perform a component control operation of the terminal by executing a program stored in the memory.

FIG. 23 is a diagram illustrating the structure of a base station in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 23, the base station may include a base station receiver 2300, a transceiver unit referring to the base station transmitter 2310, a memory (not shown), and a base station processing unit 2305 (or a base station control unit or processor). According to the above-described communication method of the base station, the base station's transceiver units 2300 and 2310, memory, and base station processing unit 2305 can operate. However, the components of the base station are not limited to the above examples. For example, a base station may include more or fewer components than those described above. In addition, the transceiver, memory, and processor may be implemented in the form of a single chip.

The transmitting and receiving unit can transmit and receive signals to and from the terminal. Here, the signal may include control information and data. To this end, the transceiver may be composed of an RF transmitter that up-converts and amplifies the frequency of the transmitted signal, and an RF receiver that amplifies the received signal with low noise and down-converts the frequency. However, this is only an example of the transceiver, and the components of the transceiver are not limited to the RF transmitter and RF receiver.

Additionally, the transceiver may receive a signal through a wireless channel, output the signal to the processor, and transmit the signal output from the processor through the wireless channel.

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

The processor can control a series of processes so that the base station can operate according to the above-described embodiment 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 a plurality of processors, and the processor may perform a component control operation of the base station by executing a program stored in a memory.

Methods according to 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.

When implemented as software, a computer-readable storage medium that stores one or more programs (software modules) may be provided. One or more programs stored in a computer-readable storage medium are configured to be executable by one or more processors in an electronic device (configured for execution). 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.

These programs (software modules, software) include random access memory, non-volatile memory including flash memory, read only memory (ROM), and electrically erasable programmable ROM. (EEPROM: Electrically Erasable Programmable Read Only Memory), magnetic disc storage device, Compact Disc-ROM (CD-ROM: Compact Disc-ROM), Digital Versatile Discs (DVDs), or other types of It can be stored in an optical storage device or magnetic cassette. Alternatively, it may be stored in a memory consisting of a combination of some or all of these. Additionally, multiple configuration memories may be included.

In addition, the program can be accessed through a communication network such as the Internet, Intranet, LAN (Local Area Network), WLAN (Wide LAN), or SAN (Storage Area Network), or a combination of these. It may be stored in an attachable storage device that can be accessed. This storage device can be connected to a device performing an embodiment of the present disclosure through an external port. Additionally, a separate storage device on a communication network may be connected to the device performing an embodiment of the present disclosure.

In the specific embodiments of the present disclosure described above, components included in the invention are expressed in singular or plural numbers depending on the specific embodiment presented. However, 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, and even components expressed in plural may be composed of singular or singular. Even expressed components may be composed of plural elements.

Meanwhile, the embodiments of the present disclosure disclosed in the specification and drawings are merely provided as specific examples to easily explain the technical content of the present disclosure and aid understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is obvious to those skilled in the art that other modifications based on the technical idea of the present disclosure can be implemented. Additionally, each of the above embodiments can be operated in combination with each other as needed. For example, a base station and a terminal may be operated by combining parts of one embodiment of the present disclosure and another embodiment. For example, parts of the first and second embodiments of the present disclosure may be combined to operate the base station and the terminal. In addition, although the above embodiments were presented based on the FDD LTE system, other modifications based on the technical idea of the above embodiments may be implemented in other systems such as a TDD LTE system, 5G or NR system.

Meanwhile, in the drawings explaining the method of the present invention, the order of explanation does not necessarily correspond to the order of execution, and the order of precedence may be changed or executed in parallel.

Alternatively, the drawings explaining the method of the present invention may omit some components and include only some components within the scope that does not impair the essence of the present invention.

In addition, the method of the present invention may be implemented by combining some or all of the content included in each embodiment within the range that does not impair the essence of the invention.

Various embodiments of the present disclosure have been described above. The above description of the present disclosure is for illustrative purposes, and the embodiments of the present disclosure are not limited to the disclosed embodiments. A person skilled in the art to which this disclosure pertains will understand that the present disclosure can be easily modified into another specific form without changing its technical idea or essential features. The scope of the present disclosure is indicated by the claims described below rather than the detailed description above, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present disclosure. do.

Claims (1)

In a control signal processing method in a wireless communication system,
Receiving a first control signal transmitted from a base station;
processing the received first control signal; and
A control signal processing method comprising transmitting a second control signal generated based on the processing to the base station.