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

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. The present disclosure relates to operations of user equipment and a base station in a wireless communication system. Specifically, the present disclosure relates to: a method for transmitting and receiving a demodulation reference signal in a wireless communication system; and an apparatus capable of performing same. According to an embodiment, a method performed by user equipment (UE) in a wireless communication system may comprise the steps of: transmitting, to a base station, UE capability information about the type of an enhanced demodulation reference signal (DMRS) and downlink control information (DCI) for scheduling a PUSCH for a plurality of cells; receiving, from the base station, configuration information about the type of the enhanced DMRS and the maximum length of the DMRS; receiving, from the base station, the DCI including an antenna port field; and identifying a DMRS port indicated by the antenna port field on the basis of the configuration information.

Description

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

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

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in frequency bands below 6 GHz ('Sub 6 GHz'), such as 3.5 gigahertz (3.5 GHz), but also in ultra-high frequency bands called millimeter waves (mmWave), such as 28 GHz and 39 GHz ('Above 6 GHz'). In addition, for 6G mobile communication technology, which is referred to as a system beyond 5G, implementation in the terahertz band (e.g., the 3 terahertz (3 THz) band at 95 GHz) is being considered to achieve transmission speeds 50 times faster and ultra-low latency reduced to one-tenth compared to 5G mobile communication technology.

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

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

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

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

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

[0008] As a result of the aforementioned development and advancements in wireless communication systems, it has become possible to provide various services, and thus measures are required to provide these services smoothly.

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

[0010] The technical problems to be solved in the various embodiments of the present disclosure are not limited to those mentioned above, and other unmentioned technical problems may be considered by those skilled in the art from the various embodiments of the present disclosure described below.

[0011] According to one embodiment of the present disclosure, a method performed by a user equipment in a wireless communication system may include: transmitting to a base station user capability information regarding a type of enhanced demodulation reference signal (DMRS) and downlink control information (DCI) for scheduling PUSCH for a plurality of cells; receiving from the base station configuration information regarding the type of enhanced DMRS and the maximum length of the DMRS; receiving from the base station the DCI including an antenna port field; and identifying a DMRS port indicated by the antenna port field based on the configuration information.

[0012] According to one embodiment of the present disclosure, a method performed by a base station in a wireless communication system may include: receiving terminal capability information from a terminal (user equipment) regarding a type of enhanced demodulation reference signal (DMRS) and downlink control information (DCI) for scheduling PUSCH for a plurality of cells; transmitting to the terminal configuration information regarding the type of enhanced DMRS and the maximum length of the DMRS; and transmitting to the terminal the DCI including an antenna port field for indicating a DMRS port.

[0013] According to one embodiment of the present disclosure, in a wireless communication system, a terminal (user equipment) comprises at least one transceiver, at least one processor communicatively coupled to the at least one transceiver, and at least one memory communicatively coupled to the at least one processor for storing instructions, wherein the instructions are executed individually or in any combination by the at least one processor, and the terminal transmits to a base station terminal capability information regarding the type of an enhanced demodulation reference signal (DMRS) and downlink control information (DCI) for scheduling PUSCH for a plurality of cells, receives from the base station configuration information regarding the type of the enhanced DMRS and the maximum length of the DMRS, receives from the base station the DCI including an antenna port field, and can identify the DMRS port indicated by the antenna port field based on the configuration information.

[0014] According to one embodiment of the present disclosure, in a wireless communication system, a base station comprises at least one transceiver, at least one processor communicatively coupled to the at least one transceiver, and at least one memory communicatively coupled to the at least one processor for storing instructions, wherein the instructions are executed individually or in any combination by the at least one processor, and the base station receives from user equipment terminal capability information regarding the type of an enhanced demodulation reference signal (DMRS) and downlink control information (DCI) for scheduling PUSCH for a plurality of cells, transmits to the terminal configuration information regarding the type of the enhanced DMRS and the maximum length of the DMRS, and transmits to the terminal the DCI including an antenna port field for indicating a DMRS port.

[0015] The various embodiments of the present disclosure described above are merely some of the preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of the various embodiments of the present disclosure can be derived and understood by those skilled in the art based on the detailed description to be described below.

[0016] The present disclosure can provide an apparatus and a method capable of effectively providing services in a wireless communication system.

[0017] The effects obtainable from the various embodiments of the present disclosure are not limited to those mentioned above, and other unmentioned effects can be clearly derived and understood by those skilled in the art based on the following detailed description.

[0018] FIG. 1 illustrates the basic structure of the time-frequency domain in a wireless communication system according to one embodiment of the present disclosure.

[0019] FIG. 2 illustrates a frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

[0020] FIG. 3 illustrates an example of a bandwidth portion setting in a wireless communication system according to one embodiment of the present disclosure.

[0021] FIG. 4 illustrates an example of setting a control area of ​​a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.

[0022] FIG. 5 illustrates the structure of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.

[0023] FIG. 6 illustrates an example of frequency axis resource allocation of a PDSCH in a wireless communication system according to one embodiment of the present disclosure.

[0024] FIG. 7 illustrates an example of time axis resource allocation of PDSCH in a wireless communication system according to one embodiment of the present disclosure.

[0025] FIG. 8 illustrates an example of allocating time-axis resources according to the subcarrier interval of a data channel and a control channel in a wireless communication system according to one embodiment of the present disclosure.

[0026] FIG. 9 illustrates the wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation, dual connectivity situation in a wireless communication system according to one embodiment of the present disclosure.

[0027] FIG. 10 illustrates an example in which an MC-DCI according to one embodiment of the present disclosure includes a plurality of FDRA fields.

[0028] FIG. 11 illustrates an example in which an MC-DCI according to one embodiment of the present disclosure includes at least one of a cell set indicator field, a scheduling cell indicator field, and a plurality of FDRA fields.

[0029] FIG. 12 illustrates an example of a field indicating frequency domain resource allocation information according to the subcarrier spacing of a cell according to one embodiment of the present disclosure.

[0030] FIG. 13 illustrates a flowchart of the operation of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0031] FIG. 14 illustrates a flowchart of the operation of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0032] FIG. 15 illustrates the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0033] FIG. 16 illustrates the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0034] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0035] In describing the embodiments, technical details that are well known in the art to which this disclosure belongs and are not directly related to this disclosure are omitted. This is intended to convey the essence of this disclosure more clearly without obscuring it by omitting unnecessary explanations.

[0036] For the same reason, some components in the attached drawings have been exaggerated, omitted, or schematically depicted. Additionally, the dimensions of each component do not entirely reflect their actual dimensions. Identical or corresponding components in each drawing have been assigned the same reference numbers.

[0037] The advantages and features of the present disclosure, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components. Furthermore, in describing the present disclosure, if it is determined that a detailed description of a related function or configuration might unnecessarily obscure the essence of the present disclosure, such detailed description is omitted. Additionally, the terms described below are defined considering their functions in the present disclosure, and these may vary depending on the intentions or conventions of the user or operator. Therefore, their definitions should be based on the content throughout the specification.

[0038] Hereinafter, a base station is an entity that performs resource allocation for terminals and may be at least one of a gNode B, eNode B, Node B, BS (Base Station), wireless access unit, base station controller, or a node on a network. A terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or a multimedia system capable of performing communication functions. In this disclosure, a downlink (DL) refers to a wireless transmission path of a signal transmitted by a base station to a terminal, and an uplink (UL) refers to a wireless transmission path of a signal transmitted by a terminal to a base station. Furthermore, while LTE or LTE-A systems may be described as examples below, embodiments of this disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, 5th generation mobile communication technologies (5G, new radio, NR) developed after LTE-A may be included therein, and the 5G below may be a concept that includes existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems with some modifications made at the discretion of a person with skilled technical knowledge, without significantly departing from the scope of the present disclosure.

[0039] At this point, it will be understood that each block of the process flow diagrams and combinations of the flow diagrams can be executed by computer program instructions. Since these computer program instructions can be loaded into the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, the instructions executed through the processor of the computer or other programmable data processing equipment create means to perform the functions described in the flow diagram block(s). Since these computer program instructions can also be stored in computer-available or computer-readable memory that can be directed toward the computer or other programmable data processing equipment to implement the function in a specific way, the instructions stored in computer-available or computer-readable memory can also produce a manufactured item containing instruction means to perform the function described in the flow diagram block(s). Since computer program instructions can be loaded onto a computer or other programmable data processing equipment, instructions that perform a series of operation steps on the computer or other programmable data processing equipment to create a process executed by the computer can also provide steps for executing the functions described in the flowchart block(s).

[0040] Additionally, each block may represent a module, segment, or part of code containing one or more executable instructions for executing a specific logical function(s). It should also be noted that in some alternative execution examples, the functions mentioned in the blocks may occur out of order. For example, two blocks described in succession may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order according to their corresponding functions.

[0041] In this embodiment, the term "part" refers to a software or hardware component such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and the "part" performs certain roles. However, the meaning of "part" is not limited to software or hardware. The "part" may be configured to reside in an addressable storage medium or configured to run one or more processors. Thus, as an example, the "part" includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and "parts" may be combined into a smaller number of components and "parts" or further separated into additional components and "parts." In addition, the components and 'parts' may be implemented to utilize one or more CPUs within the device or secure multimedia card. Also, in the embodiments, 'parts' may include one or more processors.

[0042] Wireless communication systems are evolving from providing early voice-oriented services to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as communication standards like 3GPP’s HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2’s HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE’s 802.16e.

[0043] As a representative example of the above-mentioned broadband wireless communication system, the LTE system employs the Orthogonal Frequency Division Multiplexing (OFDM) method for the downlink (DL) and the Single Carrier Frequency Division Multiple Access (SC-FDMA) method for the uplink (UL). The uplink refers to a wireless link through which a terminal (User Equipment (UE) or Mobile Station (MS)) transmits data or control signals to a base station (eNode B, or base station (BS)), and the downlink refers to a wireless link through which a base station transmits data or control signals to a terminal. The above-mentioned multiple access method can distinguish the data or control information of each user by allocating and operating time-frequency resources to be sent for each user so that they do not overlap, that is, so that orthogonality is established.

[0044] As a future communication system following LTE, that is, a 5G communication system, it must be able to freely reflect the diverse requirements of users and service providers, and therefore, services that satisfy various requirements simultaneously must be supported. Services being considered for the 5G communication system include enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliability Low Latency Communication (URLLC).

[0045] eMBB aims to provide data transmission speeds that are superior to those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must be able to provide a peak data rate of 20 Gbps in the downlink and 10 Gbps in the uplink from the perspective of a single base station. Furthermore, while providing these peak data rates, the 5G communication system must also provide an increased user-perceived data rate. To satisfy these requirements, it necessitates improvements in various transmission and reception technologies, including enhanced Multi-Input Multi-Output (MIMO) transmission technology. Additionally, while LTE transmits signals using a maximum bandwidth of 20 MHz in the 2 GHz band, the 5G communication system can meet the data transmission speeds required by using a frequency bandwidth wider than 20 MHz in frequency bands of 3–6 GHz or above 6 GHz.

[0046] Simultaneously, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide IoT, mMTC requires support for a large number of terminal connections within a cell, improved terminal coverage, enhanced battery life, and reduced terminal costs. Since IoT devices are attached to various sensors and equipment to provide communication functions, the system must be able to support a large number of terminals within a cell (e.g., 1,000,000 terminals / km²). Furthermore, due to the nature of the service, terminals supporting mMTC are likely to be located in dead zones not covered by cells, such as building basements; therefore, they may require wider coverage compared to other services provided by 5G communication systems. Terminals supporting mMTC must consist of low-cost devices, and since it is difficult to frequently replace terminal batteries, a very long battery life of 10 to 15 years may be required.

[0047] Finally, URLLC is a mission-critical cellular-based wireless communication service. For example, consider services used for remote control of robots or machinery, industrial automation, unmanned aerial vehicles, remote health care, and emergency alerts. Therefore, the communication provided by URLLC must offer very low latency and very high reliability. For instance, services supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds, and simultaneously 10 -5The following packet error rate requirements apply. Therefore, for services supporting URLLC, 5G systems must provide a Transmit Time Interval (TTI) smaller than other services, and at the same time, design considerations may be required to allocate a wide resource in the frequency band to ensure the reliability of the communication link.

[0048] In 5G, the three services of eMBB, URLLC, and Mmtc can be multiplexed and transmitted within a single system. In this case, different transmission and reception techniques and parameters may be used between the services to satisfy the different requirements of each service. Of course, 5G is not limited to the three services mentioned above.

[0049] [NR Time-Frequency Resources]

[0050] Hereinafter, the frame structure of a 5G system will be described in detail with reference to FIGS. 1 and 2.

[0051] Figure 1 illustrates the basic structure of the time-frequency domain, which is a wireless resource domain where data or control channels are transmitted in a 5G system.

[0052] Referring to FIG. 1, the horizontal axis of FIG. 1 represents the time domain, and the vertical axis represents the frequency domain. In the time and frequency domains, the basic unit of a resource is a resource element (RE, 101), which can be defined as one OFDM (Orthogonal Frequency Division Multiplexing) symbol (102) on the time axis and one subcarrier (103) on the frequency axis. In the frequency domain (For example, 12) consecutive REs can form a single resource block (Resource Block, RB, 104).

[0053] FIG. 2 illustrates a frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

[0054] FIG. 2 illustrates an example of a frame (200), subframe (201), and slot (202) structure. One frame (200) can be defined as 10ms. One subframe (201) can be defined as 1ms, and thus one frame (200) can be composed of a total of 10 subframes (201). One slot (202, 203) can be defined as 14 OFDM symbols (i.e., the number of symbols per slot ( )=14). One subframe (201) may be composed of one or more slots (202, 203), and the number of slots (202, 203) per one subframe (201) may vary depending on the setting value μ (204, 205) for the subcarrier spacing. In one example of FIG. 2, cases where μ=0 (204) and μ=1 (205) are set as the subcarrier spacing value are illustrated. When μ=0 (204), one subframe (201) may be composed of one slot (202), and when μ=1 (205), one subframe (201) may be composed of two slots (203). That is, the number of slots per one subframe ( ) may vary, and accordingly, the number of slots per frame ( ) may vary. Depending on each subcarrier spacing setting μ and It can be defined by Table 1 below.

[0055]

[0056] [Bandwidth Section (BWP)]

[0057] Next, the Bandwidth Part (BWP) setting in the 5G communication system will be explained in detail with reference to the drawing.

[0058] FIG. 3 illustrates an example of a bandwidth portion setting in a wireless communication system according to one embodiment of the present disclosure.

[0059] Referring to FIG. 3, the terminal bandwidth (UE bandwidth) (300) can be configured into two bandwidth portions. For example, in FIG. 3, it can be configured into bandwidth portion #1 (BWP#1) (301) and bandwidth portion #2 (BWP#2) (302). For example, the base station can configure at least one bandwidth portion for the terminal. For example, the base station can configure information such as that shown in Table 2 below for each bandwidth portion for the terminal.

[0060]

[0061] Of course, the settings regarding the bandwidth portion according to various embodiments of the present disclosure are not limited to the examples in Table 1, and various parameters related to the bandwidth portion may be set to the terminal in addition to the setting information according to the examples in Table 2. The above information may be transmitted by the base station to the terminal through upper layer signaling, for example, Radio Resource Control (RRC) signaling. At least one of the configured bandwidth portions may be activated. Whether the configured bandwidth portion is activated may be transmitted quasi-statically from the base station to the terminal via RRC signaling or dynamically via Downlink Control Information (DCI).

[0062] According to one embodiment, prior to the Radio Resource Control (RRC) connection, a terminal may receive an Initial Bandwidth Part (Initial BWP) for initial connection from a base station via a Master Information Block (MIB). For example, during the initial connection phase, the terminal may receive configuration information for a Control Resource Set (CORESET) and a Search Space via the MIB, through which a PDCCH can be transmitted to receive system information required for initial connection (Remaining System Information; which may correspond to RMSI or System Information Block 1; SIB1). At this time, the Control Resource Set and Search Space configured via the MIB may each be considered as Identity (ID) 0. The base station may notify the terminal via the MIB of configuration information, such as frequency allocation information, time allocation information, and numerology, for Control Resource Set #0. Additionally, the base station may notify the terminal via the MIB of configuration information regarding the monitoring period and occasion for Control Resource Set #0, i.e., configuration information for Search Space #0. The terminal may consider the frequency region set as control region #0 obtained from the MIB as the initial bandwidth portion for initial access. In this case, the identifier (ID) of the initial bandwidth portion may be considered as 0.

[0063] According to various embodiments of the present disclosure, the configuration of the bandwidth portion supported by a 5G communication system can be used for various purposes.

[0064] According to one embodiment, when the bandwidth supported by the terminal is smaller than the system bandwidth, data transmission and reception can be supported through the bandwidth portion setting. For example, when the bandwidth supported by the terminal is smaller than the system bandwidth, the base station may set the frequency position of the bandwidth portion (setting information 2) to the terminal. The terminal can transmit data to the base station at a specific frequency position within the system bandwidth. Additionally, the terminal can receive data from the base station at a specific frequency position within the system bandwidth.

[0065] According to one embodiment, a base station may support different numerologies by setting multiple bandwidth portions for a terminal. For example, to support data transmission and reception using both a 15 kHz subcarrier interval and a 30 kHz subcarrier interval for a specific terminal, the base station may set two bandwidth portions to subcarrier intervals of 15 kHz and 30 kHz, respectively. Different bandwidth portions may be frequency division multiplexed, and when the base station or the terminal wishes to transmit or receive data using a specific subcarrier interval, the bandwidth portion set to that subcarrier interval may be activated.

[0066] According to one embodiment, a base station may reduce the power consumption of a terminal by setting multiple bandwidth portions for the terminal. For example, if a terminal supports a relatively large bandwidth, such as 100 MHz, and always transmits and receives data using that bandwidth, relatively large power consumption may occur. In such a case, particularly in a situation where there is no traffic, performing monitoring of unnecessary downlink control channels using a large bandwidth of 100 MHz may be very inefficient in terms of power consumption. Accordingly, for the purpose of reducing the power consumption of the terminal, the base station may set a bandwidth portion of a relatively small bandwidth, such as 20 MHz, for the terminal. In a situation where there is no traffic, the terminal can perform monitoring operations in the 20 MHz bandwidth portion, and when data is generated, the terminal can transmit and / or receive data using the 100 MHz bandwidth portion according to the instructions of the base station.

[0067] According to one embodiment of the present disclosure, in a method for setting a bandwidth part, terminals prior to RRC connection (Connected) may receive setting information for an Initial Bandwidth Part through a Master Information Block (MIB) during the initial connection stage. For example, a terminal may receive a Control Resource Set (CORESET) for a downlink control channel through which Downlink Control Information (DCI) for scheduling a System Information Block (SIB) can be transmitted from the MIB of a Physical Broadcast Channel (PBCH). The bandwidth of the control set by the MIB may be considered as the Initial Bandwidth Part, and the terminal may receive a Physical Downlink Shared Channel (PDSCH) through which the SIB is transmitted via the set Initial Bandwidth Part. The Initial Bandwidth Part may be used for receiving the SIB, but is not limited thereto. For example, the initial bandwidth portion may be used for Other System Information (OSI), paging, or Random Access.

[0068] [Bandwidth Section (BWP) Change]

[0069] According to one embodiment, when one or more bandwidth parts are set for a terminal, the base station may instruct the terminal to change (or switch, transition) the bandwidth part using a Bandwidth Part Indicator field within the DCI. For example, referring to FIG. 3, if the currently active bandwidth part of the terminal is Bandwidth Part #1 (301), the base station may instruct the terminal to Bandwidth Part #2 (302) using a Bandwidth Part Indicator within the DCI. The terminal may perform a bandwidth part change to Bandwidth Part #2 (302) indicated by the Bandwidth Part Indicator within the received DCI.

[0070] As mentioned above, since DCI-based bandwidth portion changes can be directed by the DCI scheduling PDSCH or PUSCH, when a terminal receives a bandwidth portion change request, it must be able to receive or transmit the PDSCH or PUSCH scheduled by the corresponding DCI in the changed bandwidth portion without difficulty. To this end, the standard specifies the delay time (T) required when changing the bandwidth portion. BWP Requirements regarding ) were specified, for example, the delay time (T) required when changing the bandwidth portion BWP The requirements for ) can be defined as shown in Table 3 below.

[0071]

[0072] According to one embodiment, the requirement for the bandwidth portion change delay time may be defined as Type 1 or Type 2 depending on the capability of the terminal. The terminal may report to the base station the type of bandwidth portion delay time that the terminal can support.

[0073] According to one embodiment, in accordance with the requirements for the aforementioned bandwidth portion change delay time, when a terminal receives a DCI including a bandwidth portion change indicator in slot n, the terminal performs a change to the new bandwidth portion indicated by the bandwidth portion change indicator in slot n+T BWP It can be completed at a time no later than that, and transmission and reception for the data channel scheduled by the corresponding DCI can be performed in the changed new bandwidth portion. If the base station intends to schedule a data channel in the new bandwidth portion, the terminal's bandwidth portion change delay time (T BWP By considering ), time-domain resource allocation for a data channel can be determined. That is, when a base station schedules a data channel with a new bandwidth portion, in the method for determining time-domain resource allocation for a data channel, the data channel can be scheduled after the bandwidth portion change delay time. As a result, the terminal, when the DCI instructing the bandwidth portion change is the bandwidth portion change delay time (T BWP You may not expect to indicate a slot offset (K0 or K2) value smaller than )

[0074] According to one embodiment, when a terminal receives a DCI (e.g., DCI format 1_1 or 0_1) indicating a change in the bandwidth portion, the terminal may not perform any transmission or reception during a time interval corresponding to the time interval from the third symbol of the slot in which the PDCCH containing the said DCI was received to the beginning of the slot indicated by the slot offset value (K0 or K2) indicated by the time domain resource allocation indicator field within the said DCI. 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 said DCI is K, the terminal may not perform any transmission or reception from the third symbol of slot n to the symbol before slot n+K (i.e., the last symbol of slot n+K-1).

[0075] [PDCCH: DCI related]

[0076] Hereinafter, Downlink Control Information (DCI) in a 5G system mentioned in the present disclosure will be described in detail.

[0077] In a 5G system, scheduling information for uplink data (or Physical Uplink Shared Channel (PUSCH)) or downlink data (or Physical Downlink Shared Channel (PDSCH)) is transmitted from the base station to the terminal via DCI. The terminal can monitor the fallback DCI format and the non-fallback DCI format for PUSCH or PDSCH. The fallback DCI format may consist of fixed fields selected between the base station and the terminal, and the non-fallback DCI format may include configurable fields.

[0078] DCI can be transmitted through the Physical Downlink Control Channel (PDCCH) after undergoing channel coding and modulation processes. A Cyclic Redundancy Check (CRC) is attached to the DCI message payload, and the CRC can be scrambled into a Radio Network Temporary Identifier (RNTI) corresponding to the terminal's identity. Different RNTIs may be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control commands, or random access responses. In other words, the RNTI is not transmitted explicitly but is included in the CRC calculation process. Upon receiving a DCI message transmitted over the PDCCH, the terminal checks the CRC using the assigned RNTI; if the CRC check result is correct, the terminal knows that the message has been transmitted to it.

[0079] For example, a DCI scheduling a PDSCH for System Information (SI) can be scrambled to SI-RNTI. A DCI scheduling a PDSCH for Random Access Response (RAR) messages can be scrambled to RA-RNTI. A DCI scheduling a PDSCH for Paging messages can be scrambled to P-RNTI. A DCI notifying a Slot Format Indicator (SFI) can be scrambled to SFI-RNTI. A DCI notifying Transmit Power Control (TPC) can be scrambled to TPC-RNTI. A DCI scheduling a terminal-specific PDSCH or PUSCH can be scrambled to C-RNTI (Cell RNTI).

[0080] DCI format 0_0 can be used as a countermeasure DCI for scheduling PUSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 0_0 with the CRC scrambled with C-RNTI may include, for example, the information in Table 4. Of course, DCI format 0_0 with the CRC scrambled with C-RNTI is not limited to the examples in Table 4.

[0081]

[0082] DCI format 0_1 ​​can be used as a non-defense DCI for scheduling PUSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 0_1 ​​with the CRC scrambled with C-RNTI may include, for example, the information in Table 5. Of course, DCI format 0_1 ​​with the CRC scrambled with C-RNTI is not limited to the examples in Table 5.

[0083]

[0084]

[0085] DCI format 1_0 can be used as a countermeasure DCI for scheduling PDSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 1_0 with the CRC scrambled with C-RNTI may include, for example, the information in Table 6 below. Of course, DCI format 1_0 with the CRC scrambled with C-RNTI is not limited to the examples in Table 6.

[0086]

[0087] DCI format 1_1 can be used as a non-defense DCI for scheduling PDSCH, whereby the CRC can be scrambled with C-RNTI. DCI format 1_1 with the CRC scrambled with C-RNTI may include, for example, the information in Table 7 below. Of course, DCI format 1_1 with the CRC scrambled with C-RNTI is not limited to the examples in Table 7.

[0088]

[0089] [PDCCH: CORESET, REG, CCE, Search Space]

[0090] Hereinafter, a downlink control channel in a 5G communication system mentioned in the present disclosure will be described in detail with reference to the drawings.

[0091] Figure 4 illustrates an example of a Control Resource Set (CORESET) setting in which a downlink control channel is transmitted in a 5G wireless communication system.

[0092] Additionally, FIG. 4 illustrates an example in which two control areas (control area #1 (401), control area #2 (402)) are set within a terminal bandwidth part (UE bandwidth part) (410) on the frequency axis and a slot (420) on the time axis. For example, the control areas (401, 402) can be set to a specific frequency resource (403) within the entire terminal bandwidth part (410) on the frequency axis. On the time axis, they can be set to one or multiple OFDM symbols and can be defined as the control area length (Control Resource Set Duration, 404). For example, referring to FIG. 4, control area #1 (401) can be set to a control area length of two symbols, and control area #2 (402) can be set to a control area length of one symbol.

[0093] According to one embodiment, a control domain in a 5G communication system may be established through upper-layer signaling (e.g., System Information, Master Information Block (MIB), Radio Resource Control (RRC) signaling) to a terminal of a base station. In the present disclosure, the statement that a base station establishes a control domain to a terminal may mean that the base station provides the terminal with information such as a control domain identifier, a frequency location of the control domain, and a symbol length of the control domain. For example, the information provided by the base station to the terminal to establish a control domain may include the information in Table 8 below. Of course, the information provided by the base station to the terminal to establish a control domain is not limited to the examples in Table 8.

[0094]

[0095] According to one embodiment, in Table 8, the tci-StatesPDCCH (simply named TCI (Transmission Configuration Indication) state) configuration information may include, but is not limited to, information on one or more SS (Synchronization Signal) / PBCH (Physical Broadcast Channel) block indices or CSI-RS (Channel State Information Reference Signal) indices that are in a QCL (Quasi Co Located) relationship with the DMRS transmitted in the corresponding control area.

[0096] FIG. 5 illustrates the structure of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure. For example, the structure of the downlink control channel illustrated in FIG. 5 may correspond to an example of a basic unit of time and frequency resources constituting a downlink control channel that can be used in a 5G communication system.

[0097] In one embodiment of the present disclosure, the basic unit of time and frequency resources constituting a control channel may be referred to as a REG (Resource Element Group, 503), and the REG (503) may be defined as 1 OFDM symbol (501) on the time axis and 1 PRB (Physical Resource Block, 502) on the frequency axis, i.e., 12 subcarriers. A base station may concatenate REGs (503) to form a downlink control channel allocation unit.

[0098] According to one embodiment, as illustrated in FIG. 5, if the basic unit to which a downlink control channel is allocated in 5G is called a CCE (Control Channel Element, 504), then 1 CCE (504) may be composed of a plurality of REGs (503). For example, referring to FIG. 5, a REG (503) may be composed of 12 REs (Resource elements). If 1 CCE (504) is composed of 6 REGs (503), then 1 CCE (504) may be composed of 72 REs. When a downlink control area is established, the area may be composed of a plurality of CCEs (504), and a specific downlink control channel may be mapped to one or a plurality of CCEs (504) and transmitted according to an Aggregation Level (AL) within the control area. The CCEs (504) in the control area are distinguished by numbers, and the numbers of the CCEs (504) can be assigned according to a logical mapping method.

[0099] According to one embodiment, the basic unit of the downlink control channel shown in FIG. 5, namely the REG (503), may include both the REs to which the DCI is mapped and the DMRS (505), which is a reference signal for decoding the DCI, to which the area is mapped. In this case, as shown in FIG. 5, three DMRS (505) may be transmitted within one REG (503). The number of CCEs required to transmit the PDCCH may be 1, 2, 4, 8, or 16 depending on the Aggregation Level (AL), and in this case, different numbers of CCEs may be used to implement link adaptation of the downlink control channel. For example, when AL=L, one downlink control channel may be transmitted through L CCEs. A terminal may need to detect a signal without knowing information about the downlink control channel. In this case, a search space representing a set of CCEs may be defined for blind decoding. A 'search space' is a set of downlink control channel candidates consisting of CCEs that a terminal must attempt to decode at a given aggregation level, and since there are various aggregation levels that form a group of 1, 2, 4, 8, or 16 CCEs, a terminal may have multiple search spaces. A search space set can be defined as a set of search spaces at all configured aggregation levels.

[0100] According to one embodiment, the search space may be classified into a common search space and a terminal-specific (UE-specific) search space. A certain group of terminals or all terminals may examine the common search space of the PDCCH to receive cell-common control information, such as dynamic scheduling or paging messages regarding system information. For example, PDSCH scheduling allocation information for the transmission of an SIB containing cell operator information, etc., may be received by examining the common search space of the PDCCH. In the case of the common search space, since a certain group of terminals or all terminals must receive the PDCCH, it may be defined as a set of pre-agreed CCEs. Scheduling allocation information for a terminal-specific PDSCH or PUSCH may be received by examining the terminal-specific search space of the PDCCH. The terminal-specific search space may be defined terminal-specifically as a function of the terminal's identity and various system parameters.

[0101] According to one embodiment, in 5G, parameters for the search space for a PDCCH can be set from the base station to the terminal via upper layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station may set to the terminal the number of PDCCH candidates at each aggregation level L, the monitoring period for the search space, the occasion for monitoring in slot-symbol units for the search space, the search space type (common search space or terminal-specific search space), the combination of DCI format and RNTI to be monitored in the search space, and the control domain index to be monitored in the search space. For example, the parameters for the search space for a PDCCH set from the base station to the terminal may include the information in Table 9. Of course, the parameters for the search space for a PDCCH set from the base station to the terminal are not limited to the examples in Table 9.

[0102]

[0103]

[0104] According to various embodiments of the present disclosure, a base station may set at least one set of search spaces for a terminal according to setting information.

[0105] According to one embodiment, a base station may set search space set 1 and search space set 2 for a terminal. For example, the base station may set the terminal to monitor DCI format A, scrambled with X-RNTI in search space set 1, in a common search space. For example, the base station may set the terminal to monitor DCI format B, scrambled with Y-RNTI in search space set 2, in a terminal-specific search space.

[0106] According to the configuration information according to one embodiment of the present disclosure, one or more sets of search spaces may exist in a common search space or a terminal-specific search space. For example, search space set #1 and search space set #2 may be configured as a common search space, and search space set #3 and search space set #4 may be configured as a terminal-specific search space.

[0107] According to one embodiment, a combination of the following DCI format and RNTI can be monitored in a common search space. Of course, it is not limited to the following examples.

[0108] - 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

[0109] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0110] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0111] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0112] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0113] According to one embodiment, a combination of the following DCI format and RNTI may be monitored in a terminal-specific search space. Of course, it is not limited to the following examples.

[0114] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0115] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0116] According to one embodiment, the specified RNTIs may follow the following definitions and uses.

[0117] - C-RNTI (Cell RNTI): Used for terminal-specific PDSCH scheduling

[0118] - TC-RNTI (Temporary Cell RNTI): Used for terminal-specific PDSCH scheduling

[0119] - CS-RNTI (Configured Scheduling RNTI): Used for semi-statically configured terminal-specific PDSCH scheduling.

[0120] - RA-RNTI (Random Access RNTI): Used for PDSCH scheduling during the random access phase

[0121] - P-RNTI (Paging RNTI): Used for PDSCH scheduling where paging is transmitted.

[0122] - SI-RNTI (System Information RNTI): Used for PDSCH scheduling where system information is transmitted.

[0123] - INT-RNTI (Interruption RNTI): Used to indicate whether PDSCH is pucturing.

[0124] - TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to instruct power control commands to the PUSCH

[0125] - TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to instruct power control commands to the PUCCH

[0126] - TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to instruct power regulation commands to the SRS

[0127] According to one embodiment, DCI formats may follow the definitions in Table 10 below. Of course, DCI formats are not limited to the examples in Table 10.

[0128]

[0129] According to one embodiment, in a 5G communication system, the search space of aggregation level L in a control area p and a search space set s can be expressed as shown in the following mathematical formula 1.

[0130] [Mathematical Formula 1]

[0131]

[0132] -- L: Lamination Level

[0133] -- n CI : Carrier Index

[0134] -- N CCE,p : Total number of CCEs existing within control domain p

[0135] -- n μ s,f : Slot Index

[0136] -- M (L)p,s,max : Number of PDCCH candidates at assembly level L

[0137] -- m snCI = 0, ..., M (L) p,s,max -1: PDCCH candidate index of aggregation level L

[0138] -- i = 0, ..., L-1

[0139] --

[0140] -- n RNTI : Terminal identifier

[0141] The value may be 0 for the common search space.

[0142] In the case of a terminal-specific search space, the value may correspond to a value that changes according to the terminal's identity (C-RNTI or ID set by the base station for the terminal) and the time index.

[0143] In a 5G communication system, as multiple sets of search spaces can be configured with different parameters (e.g., the parameters in Table 8), the set of search space sets monitored by the terminal at each point in time may vary. For example, if search space set #1 is configured with an X-slot period and search space set #2 is configured with a Y-slot period and X and Y are different, the terminal may monitor both search space set #1 and search space set #2 in a specific slot, and monitor either search space set #1 or search space set #2 in a specific slot.

[0144] A terminal can perform UE capability reporting for each subcarrier interval when it has multiple PDCCH monitoring locations within a slot, and the concept of a Span can be used in this case. A Span refers to a sequence of consecutive symbols within a slot through which the terminal can monitor a PDCCH, and each PDCCH monitoring location is within one Span. A Span can be expressed as (X,Y), where x represents the minimum number of symbols that must be separated between the first symbols of two consecutive Spans, and Y represents the number of consecutive symbols through which a PDCCH can be monitored within one Span. In this case, the terminal can monitor a PDCCH within a Span in the interval of Y symbols from the first symbol of the Span.

[0145] [PDSCH: Regarding Frequency Resource Allocation]

[0146] FIG. 6 illustrates an example of frequency axis resource allocation of a physical downlink shared channel (PDSCH) in a wireless communication system according to one embodiment of the present disclosure.

[0147] Referring to FIG. 6, a method for allocating frequency axis resources configurable through an upper layer in an NR wireless communication system according to various embodiments of the present disclosure may include three frequency axis resource allocation methods: type 0 (600), type 1 (605), and a dynamic switch (610).

[0148] Referring to FIG. 6, in one embodiment, when a terminal is configured to use only resource type 0 through upper layer signaling (600), some downlink control information (DCI) that assigns PDSCH to the terminal may include a bitmap consisting of NRBG bits. The conditions associated with this will be described later. Here, 'NRBG' refers to the number of RBGs (resource block groups) determined as shown in Table 11 below according to the BWP size assigned by the BWP indicator and the upper layer parameter rbg-Size, and data may be transmitted to the RBG indicated as 1 by the bitmap.

[0149]

[0150] In one embodiment, when a terminal is configured to use only resource type 1 through upper layer signaling (605), some DCIs that assign PDSCH to the terminal are It may include frequency axis resource allocation information consisting of bits. Conditions for this will be described later. Through this, the base station can set the starting VRB (620) and the length (625) of the frequency axis resources continuously allocated therefrom.

[0151] According to one embodiment, when a terminal is configured to use both resource type 0 and resource type 1 through upper layer signaling (610), some DCIs that allocate PDSCH to the terminal may include frequency axis resource allocation information composed of bits of the larger value (Max (payload for RA type 0, payload for RA type 1)) (635) of the payload (615) for setting resource type 0 and the payload (620, 625) for setting resource type 1. Conditions related thereto will be described later. Here, one bit may be added to the first part (MSB) of the frequency axis resource allocation information within the DCI, and if the added bit has a value of '0', it indicates that resource type 0 is used, and if the added bit has a value of '1', it indicates that resource type 1 is used.

[0152] [PDSCH / PUSCH: Time Resource Allocation]

[0153] Hereinafter, a time domain resource allocation method for a data channel in a next-generation mobile communication system (5G or NR system) mentioned in the present disclosure will be described.

[0154] In various embodiments of the present disclosure, a base station may set a table for time domain resource allocation information for a Physical Downlink Shared Channel (PDSCH) and a Physical Uplink Shared Channel (PUSCH) to a terminal using upper layer signaling (e.g., RRC signaling). For example, for PDSCH, a table consisting of up to maxNrofDL-Allocations = 16 entries may be set, and for PUSCH, a table consisting of up to maxNrofUL-Allocations = 16 entries may be set.

[0155] In one embodiment, the time domain resource allocation information may include PDCCH-to-PDSCH slot timing (K0) (e.g., K0 may represent a 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), PDCCH-to-PUSCH slot timing (K2) (e.g., K2 may correspond to a time interval in slot units between the time when the PDCCH is received and the time when the PUSCH scheduled by the received PDCCH is transmitted), information regarding the position and length of the start symbol in which the PDSCH or PUSCH is scheduled within the slot, and the mapping type of the PDSCH or PUSCH. For example, the time domain resource allocation information transmitted from the base station to the terminal may include information such as that shown in Table 12 or Table 13 below, but is not limited thereto.

[0156]

[0157]

[0158] According to one embodiment, a base station may notify a terminal of one of the entries in a table for time domain resource allocation information via L1 (layer-1) signaling (e.g., DCI). For example, one of the entries in the table for time domain resource allocation information may be indicated to the terminal as a 'time domain resource allocation' field within the DCI. The terminal may obtain time domain resource allocation information for PDSCH or PUSCH based on the DCI received from the base station.

[0159] FIG. 7 illustrates an example of time axis resource allocation of PDSCH in a wireless communication system according to one embodiment of the present disclosure.

[0160] Referring to FIG. 7, in one embodiment, the base station uses an upper layer to set the subcarrier spacing (SCS) (μ) of the data channel and control channel. PDSCH , μ PDCCH The time axis position of the PDSCH resource can be indicated according to the scheduling offset (K0) value, and the OFDM symbol start position (S) (700) and length (L) (705) within one slot that are dynamically indicated through DCI.

[0161] FIG. 8 illustrates an example of allocating time-axis resources according to the subcarrier interval of a data channel and a control channel in a wireless communication system according to one embodiment of the present disclosure.

[0162] Referring to FIG. 8, when the subcarrier spacing of the data channel and the control channel is the same (800,μ PDSCH = μ PDCCH), since the slot numbers for data and control are the same, the base station and the terminal can generate a scheduling offset by aligning with a predetermined slot offset K0. On the other hand, when the subcarrier spacing of the data channel and the control channel is different (805,μ PDSCH ≠ μ PDCCH Since the slot numbers for data and control are different, the base station and the terminal can generate a scheduling offset based on the subcarrier interval of the PDCCH and in accordance with a predetermined slot offset K0.

[0163] [Regarding Terminal Capability Reporting]

[0164] In a wireless communication system according to various embodiments of the present disclosure, a terminal may perform a procedure to report the capability supported by the terminal to the base station while connected to the base station. Hereinafter, this may be referred to as a UE capability report in the present disclosure.

[0165] According to one embodiment, a base station may transmit a UE capability enquiry message requesting a capability report to a terminal in a connected state. The UE capability enquiry message may include a request for a terminal capability by the base station's RAT (radio access technology) type. The request by RAT type may include information on supported frequency band combinations, etc. Additionally, in the case of the UE capability enquiry message, multiple UE capabilities by RAT type may be requested through a single RRC message container transmitted by the base station, or the base station may transmit to the terminal multiple times a UE capability enquiry message containing a request for a terminal capability by each RAT type. That is, the UE capability inquiry may be repeated multiple times within a single message, and the terminal may construct a corresponding UE capability information message and report it multiple times. In a next-generation mobile communication system, a UE capability request can be made for NR, LTE, EN-DC (E-UTRA - NR dual connectivity), and MR-DC (Multi-RAT dual connectivity). In addition, the above terminal capability inquiry message is generally transmitted initially after the terminal is connected to the base station, but the base station may request it under any conditions when necessary.

[0166] In the above step, the terminal that receives a request for a UE capability report from the base station configures the terminal capability according to the RAT type and band information requested from the base station. The following example may refer to a method for a terminal to configure UE capability in an NR system.

[0167] 1) If the terminal receives a list of LTE and / or NR bands from the base station via a UE capability request, the terminal configures a band combination (BC) for EN-DC and NR stand alone (SA). That is, it constructs a candidate list of BCs for EN-DC and NR SA based on the bands requested from the base station via FreqBandList. Additionally, the bands may have priority in the order listed in FreqBandList.

[0168] 2) If the base station requests a UE capability report by setting the “eutra-nr-only” flag or the “eutra” flag, the terminal completely removes NR SA BCs from the above-mentioned list of configured BC candidates. This operation may occur only when the LTE base station (eNB) requests the “eutra” capability.

[0169] 3) Subsequently, the terminal may remove fallback BCs from the candidate list of BCs configured in the above step. Here, a fallback BC refers to a BC that can be obtained by removing a band corresponding to at least one SCell from any BC, and this step may be omitted because the BC before removing the band corresponding to at least one SCell already covers the fallback BC. This step may also be applied to MR-DC. That is, for example, it may also be applied to LTE bands. The BCs remaining after this step may correspond to the final "candidate BC list".

[0170] 4) The terminal selects the BCs to be reported by selecting BCs that match the requested RAT type from the final "Candidate BC List" above. In this step, the terminal constructs the supportedBandCombinationList in a predetermined order. That is, the terminal can construct the BCs and UE capabilities to be reported according to the pre-set order of rat-Type (nr -> eutra-nr -> eutra). Additionally, it can construct a featureSetCombination for the constructed supportedBandCombinationList and construct a list of "Candidate Feature Set Combinations" from the Candidate BC List from which the list of fallback BCs (containing capabilities of the same or lower level) has been removed. The above "Candidate Feature Set Combinations" include feature set combinations for both NR and EUTRA-NR BCs and can be obtained from the feature set combinations of the UE-NR-Capabilities and UE-MRDC-Capabilities containers.

[0171] 5) Also, if the requested rat Type is eutra-nr and has an influence, featureSetCombinations can be included in both the UE-MRDC-Capabilities and UE-NR-Capabilities containers. However, the NR feature set can only be included in UE-NR-Capabilities.

[0172] After terminal capability is configured, the terminal can transmit a terminal capability information message containing the terminal capability to the base station. Based on the terminal capability received from the terminal, the base station can subsequently perform appropriate scheduling and transmission / reception management for the terminal.

[0173] [CA / DC Related]

[0174] FIG. 9 illustrates the wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation (CA), and dual connectivity (DC) situation according to one embodiment of the present disclosure.

[0175] Referring to FIG. 9, the wireless protocol of the next-generation mobile communication system can be composed of NR SDAP (Service Data Adaptation Protocol S25, S70), NR PDCP (Packet Data Convergence Protocol S30, S65), NR RLC (Radio Link Control S35, S60), and NR MAC (Medium Access Control S40, S55) at the terminal and the NR base station, respectively.

[0176] The main functions of NR SDAP (S25, S70) may include some of the following functions, but are not limited thereto.

[0177] - User data transfer function (transfer of user plane data)

[0178] - Mapping function between a QoS flow and a DRB for both DL and UL for uplink and downlink

[0179] - Marking QoS flow ID for uplink and downlink (marking QoS flow ID in both DL and UL packets)

[0180] - Function to map reflective QoS flow to data bearers for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

[0181] According to one embodiment, regarding an SDAP layer device, the terminal may receive a setting via an RRC message regarding whether to use the header of the SDAP layer device or the functions of the SDAP layer device for each PDCP layer device, for each bearer, or for each logical channel. If the SDAP header is set, the terminal may instruct the NAS QoS reflective setting 1-bit indicator (NAS reflective QoS) and the AS QoS reflective setting 1-bit indicator (AS reflective QoS) of the SDAP header to update or reset the mapping information for the QoS flow of the uplink and downlink and the data bearer. The SDAP header may include QoS flow ID information indicating QoS. The QoS information may be used for data processing priority, scheduling information, etc., to support smooth service.

[0182] According to one embodiment, the main functions of the NR PDCP (S30, S65) may include some of the following functions, but the functions of the NR PDCP (1030, 1065) are not limited to the following examples.

[0183] - Header compression and decompression features (ROHC only)

[0184] - User data transfer function (Transfer of user data)

[0185] - Sequential delivery function (In-sequence delivery of upper layer PDUs)

[0186] - Out-of-sequence delivery of upper layer PDUs

[0187] - Reordering function (PDCP PDU reordering for reception)

[0188] - Duplicate detection function (Duplicate detection of lower layer SDUs)

[0189] - Retransmission of PDCP SDUs

[0190] - Encryption and decryption functions (Ciphering and deciphering)

[0191] - Timer-based SDU discard in uplink.

[0192] In the functions described above, the reordering function of the NR PDCP (S30, S65) device refers to a function of reordering PDCP PDUs received from a lower layer in order based on the PDCP SN (sequence number), and may include a function of transmitting data to an upper layer in the reordered order. Alternatively, the reordering function of the NR PDCP device may include a function of transmitting immediately without considering the order, a function of recording lost PDCP PDUs by reordering, a function of reporting the status of lost PDCP PDUs to the transmitting side, and a function of requesting retransmission of lost PDCP PDUs.

[0193] According to one embodiment, the main functions of the NR RLC (S35, S60) may include some of the following functions. Of course, the functions of the NR RLC (S35, S60) are not limited to the following examples.

[0194] - Data transfer function (Transfer of upper layer PDUs)

[0195] - Sequential delivery function (In-sequence delivery of upper layer PDUs)

[0196] - Out-of-sequence delivery of upper layer PDUs

[0197] - ARQ function (Error Correction through ARQ)

[0198] - Concatenation, segmentation, and reassembly functions of RLC SDUs

[0199] - Re-segmentation function (Re-segmentation of RLC data PDUs)

[0200] - Reordering function (Reordering of RLC data PDUs)

[0201] - Duplicate detection

[0202] - Error detection function (Protocol error detection)

[0203] - RLC SDU discard function

[0204] RLC re-establishment function

[0205] In the above, the in-sequence delivery function of the NR RLC device refers to the function of delivering RLC SDUs received from a lower layer to an upper layer in order. The in-sequence delivery function of the NR RLC device may include a function of reassembling and delivering the RLC SDUs when the original RLC SDU is received divided into multiple RLC SDUs, a function of rearranging the received RLC PDUs based on an RLC SN (sequence number) or PDCP SN (sequence number), a function of recording lost RLC PDUs by rearranging the order, a function of reporting the status of lost RLC PDUs to the transmitting side, and a function of requesting retransmission of lost RLC PDUs. The in-sequence delivery function of the NR RLC device may include a function to deliver only the RLC SDUs prior to the lost RLC SDU in order to the upper layer if there is a lost RLC SDU, or a function to deliver all RLC SDUs received before the timer started in order to the upper layer if a predetermined timer has expired even if there is a lost RLC SDU. Alternatively, the in-sequence delivery function of the NR RLC device may include a function to deliver all RLC SDUs received up to the present in order to the upper layer if a predetermined timer has expired even if there is a lost RLC SDU.In addition, the RLC PDUs described above may be processed in the order they are received (regardless of the order of sequence numbers, in the order of arrival) and delivered to the PDCP device out of order (out-of-sequence delivery). In the case of segments, segments stored in a buffer or to be received later may be received, reconstructed into a single complete RLC PDU, processed, and delivered to the PDCP device. The NR RLC layer may not include a concatenation function, and this function may be performed by the NR MAC layer or replaced by the multiplexing function of the NR MAC layer.

[0206] In the present disclosure, the out-of-sequence delivery function of an NR RLC device means a function of delivering RLC SDUs received from a lower layer directly to an upper layer regardless of order, and may include a function of reassembling and delivering them when an original RLC SDU is received divided into multiple RLC SDUs, and may include a function of storing the RLC SN or PDCP SN of the received RLC PDUs and sorting the order to record the lost RLC PDUs.

[0207] According to one embodiment, the NR MAC (S40, S55) may be connected to multiple NR RLC layer devices configured in a terminal, and the main functions of the NR MAC may include some of the following functions, but are not limited to the examples below.

[0208] - Mapping function (Mapping between logical channels and transport channels)

[0209] - Multiplexing and demultiplexing functions (Multiplexing / demultiplexing of MAC SDUs)

[0210] - Scheduling information reporting function

[0211] - HARQ function (Error correction through HARQ)

[0212] - Priority handling between logical channels of one UE

[0213] - Priority handling between UEs by means of dynamic scheduling

[0214] - MBMS service identification function

[0215] - Transport format selection function

[0216] - Padding

[0217] According to one embodiment, the NR PHY layer (S45, S50) can perform the operation of channel coding and modulating upper layer data, making it into an OFDM symbol and transmitting it to a wireless channel, or demodulating the OFDM symbol received through the wireless channel and channel decoding it to transmit it to an upper layer.

[0218] The detailed structure of the above wireless protocol structure may vary depending on the carrier (or cell) operation method. For example, when a base station transmits data to a terminal based on a single carrier (or cell), the base station and the terminal use a protocol structure having a single structure for each layer, as shown in S00. On the other hand, when a base station transmits data to a terminal based on Carrier Aggregation (CA) using multiple carriers in a single TRP, the base station and the terminal use a protocol structure that has a single structure up to the RLC, as shown in S10, but multiplexes the PHY layer through the MAC layer. As another example, when a base station transmits data to a terminal based on Dual Connectivity (DC) using multiple carriers in multiple TRPs, the base station and the terminal use a protocol structure that has a single structure up to the RLC, as shown in S20, but multiplexes the PHY layer through the MAC layer.

[0219] [Regarding MC-DCI]

[0220] Hereinafter, a scheduling method using MC-DCI (Multi-cell scheduling DCI) according to one embodiment of the present disclosure is described. The embodiment may be operated in combination with other embodiments.

[0221] According to one embodiment of the present disclosure, one DCI may mean Single-DCI or one DCI format, and a plurality of DCIs may mean Multi-DCI or a plurality of DCI formats.

[0222] In various embodiments of the present disclosure, one DCI may be transmitted and received through one PDCCH and / or one PDCCH, and multiple DCIs may be transmitted and received through multiple PDCCHs and / or multiple PDCCHs.

[0223] In various embodiments of the present disclosure, a terminal may receive a DCI. The DCI may include scheduling information for a cell. For example, in the case of DCI format 0_0 / 0_1 / 0_2, one PUSCH may be scheduled for one uplink cell. Also, in the case of DCI format 1_0 / 1_1 / 1_2, one PDSCH may be scheduled for one downlink cell. The cell to be scheduled may be indicated by the CIF (carrier indication field) of the DCI format.

[0224] However, according to this method, when PDSCH or PUSCH is scheduled in each of multiple cells, multiple DCIs must be transmitted and received. Consequently, a large amount of DCI overhead may occur. To reduce DCI overhead, a single DCI can schedule PDSCH or PUSCH in each of multiple cells. For convenience, this may be referred to as MC-DCI. In the present disclosure, MC-DCI may correspond to a single DCI that schedules PDSCH and / or PUSCH in each of multiple cells. In this case, the DCI format of the MC-DCI may be DCI format 1_X or 1_3 for PDSCH scheduling, and DCI format 0_X or 0_3 for PUSCH scheduling.

[0225] According to one embodiment, within a specific cell, the terminal may report to the base station, as a terminal capability, the number of candidate cell sets that can be scheduled via MC-DCI. Here, 'cell set' may mean a set containing multiple cells. For example, cell set 1 may include cell 1, cell 2, cell 3, and cell 4, and cell set 2 may include cell 5, cell 6, cell 7, and cell 8. The number of cells that can be included in a cell set may be up to four, and the cells included in each cell set may not overlap with each other. In this case, the number of candidate cell sets that the terminal may report as a terminal capability may be one or two or more.

[0226] In one embodiment, when a terminal reports that the number of candidate cell sets that can be scheduled via MC-DCI within a specific cell is one, the terminal can expect that there is no cell set indicator field in the MC-DCI, and when the terminal receives the MC-DCI from the base station, it can expect scheduling for cells within one cell set.

[0227] In one embodiment, when a terminal reports two or more candidates for a set of cells that can be scheduled via MC-DCI within a specific cell, the terminal can expect that a cell set indicator field exists within the MC-DCI, and the terminal can receive a cell set index from the base station through said field. The terminal can receive scheduling information for one or more cells within one of a plurality of cell sets via MC-DCI. The following description assumes that the number of candidates for a set of cells reported by the terminal is one, but the case where the number of candidates for a set of cells is two or more may not be excluded.

[0228] According to one embodiment, cells that can be scheduled in the MC-DCI may be configured to an upper layer. For example, assuming that the MC-DCI can schedule Cell 0, Cell 1, Cell 2, and Cell 3 (simultaneously), when a terminal receives the MC-DCI, it may receive scheduling information for Cell 0, Cell 1, Cell 2, and Cell 3. That is, the terminal may obtain scheduling information for Cell 0, Cell 1, Cell 2, and Cell 3 from the MC-DCI. For example, it may be configured from an upper layer that the MC-DCI can schedule Cell 0, Cell 1, Cell 2, and Cell 3. Here, the scheduling information may include Time Domain Resource Allocation (TDRA) information and / or Frequency Domain Resource Allocation (FDRA) information regarding the transmission and reception of data channels (PDSCH for downlink and PUSCH for uplink) in each cell. Accordingly, the terminal can obtain scheduling information for each cell through the MC-DCI and can transmit and receive data channels to each cell.

[0229] There may be cases where the base station is unable to perform scheduling for all cells configured for the terminal under specific circumstances. Alternatively, there may be cases where scheduling is impossible for at least some of the multiple cells configured for the terminal by the base station. For example, even if the base station has configured four cells (e.g., Cell 0, Cell 1, Cell 2, Cell 3) for MC-DCI scheduling for the terminal, some of these cells may not be scheduled, for example, because they have been scheduled for another terminal, or due to poor channel conditions, or for various other reasons. In this case, the base station may instruct the terminal to schedule the cells among the pre-configured cells for MC-DCI scheduling. For example, the base station may instruct the terminal to schedule one or more cells that are (actually) scheduled among the multiple cells configured for MC-DCI scheduling.

[0230] According to one embodiment, a method for a base station to instruct a terminal to schedule cells among pre-configured cells scheduled by MC-DCI may include one of the following two methods. Alternatively, a method for a base station to instruct a terminal to schedule cells among pre-configured cells scheduled by MC-DCI may be based on a combination of at least one of the following two methods.

[0231] As a first method for a base station according to various embodiments of the present disclosure to indicate to a terminal the scheduling cells among the pre-configured cells that are scheduled by MC-DCI, the terminal may obtain from the MC-DCI information indicating the co-scheduled cells among the pre-configured cells (e.g., Cell 0, Cell 1, Cell 2, Cell 3). That is, among a plurality of cells configured to be scheduled by MC-DCI, one or more cells that are (actually) co-scheduled through the MC-DCI may be identified based on the MC-DCI. More specifically, the base station may set up a table for the terminal containing the co-scheduled cells. For example, the rows of this table may have a unique index. The index of each row may include (and / or each row) the indices of the co-scheduled cells. For example, {cell 0, cell 1} can be set in row 0, {cell 2, cell 3} in row 1, and {cell 0, cell 1, cell 2, cell 3} in row 2. For an example of a table set for a terminal, refer to Table 14 below.

[0232]

[0233] The terminal can obtain a value indicating a row index from the MC-DCI. Accordingly, the terminal can determine the cells to be scheduled based on the value indicating the row index. For example, the MC-DCI may contain information regarding the row index, and the terminal can identify the cells to be scheduled based on the row index obtained from the MC-DCI and the table. For example, if row 0 is indicated from the MC-DCI, the terminal can identify that Cell 0 and Cell 1 are the cells to be scheduled. For example, if row 1 is indicated from the MC-DCI, the terminal can identify that Cell 2 and Cell 3 are the cells to be scheduled. For example, if row 2 is indicated from the MC-DCI, the terminal can identify that Cell 0, Cell 1, Cell 2, and Cell 3 are the cells to be scheduled.

[0234] In the present disclosure, a table for a mapping relationship between a scheduled cell (or an index of a scheduled cell) and an index indicated by a DCI is established, and a scheduled cell can be identified based on the table and the index indicated by the DCI.

[0235] Although the present disclosure describes an embodiment in which cells scheduled simultaneously are identified based on the index of a row of a table, the present disclosure is not limited thereto, and, for example, may be identified based on the index of a column of a table, in which case the row in the above-described embodiment may be replaced with a column.

[0236] In the present disclosure, if there are two or more candidates for a set of cells that can be scheduled through MC-DCI received by a terminal within a specific cell, the terminal may set a table as described above for each set of cells, and the terminal may determine which set of cells to use through a cell set indicator field within the MC-DCI.

[0237] A second method for a base station according to various embodiments of the present disclosure to instruct a terminal to schedule cells among pre-configured cells that are scheduled by MC-DCI, wherein the terminal can determine whether there is scheduling information for one or more cells based on the FDRA field of MC-DCI.

[0238] In one embodiment, if the terminal reports that there is one candidate set of cells that can be scheduled via MC-DCI within a specific cell, the terminal can expect that there are FDRA fields in MC-DCI equal to the number of cells included in the one set of cells. At this time, if the terminal has not received upper-layer signaling settings such as the table mentioned in the first method, the terminal can determine whether scheduling information for each cell exists based on one or more FDRA fields in MC-DCI.

[0239] In one embodiment, if a terminal reports the number of candidate cell sets that can be scheduled via MC-DCI within a specific cell as two or more through a terminal capability report, the terminal can expect that there will be FDRA fields corresponding to the maximum value among the number of cells included in each of the two or more cell sets. For example, if the terminal reports the number of candidate cell sets as two, and the first cell set contains three cells and the second cell set contains four cells, the terminal can expect that there will be four FDRA fields in the MC-DCI, which is the maximum value among the number of cells included in the first and second cell sets, respectively.

[0240] - If the terminal has not received upper-layer signaling settings, such as the table mentioned in the first method above, for all cell sets, the terminal can determine whether scheduling information for each cell exists based on the FDRA fields in MC-DCI, and if the number of cells in the cell set indicated by the cell set indicator field is less than the number of FDRA fields, the terminal can consider the FDRA fields corresponding to the number of cells in the indicated cell set as ascending indices of the FDRA fields, and ignore the FDRA fields corresponding to indices greater than the number of cells.

[0241] - If the terminal has received upper-layer signaling settings, such as the table mentioned in the first method above, for a specific set of cells but has not received them for the remaining set of cells, the terminal can expect that a scheduling cell indicator field capable of indicating the index of a specific row within the table set as upper-layer signaling, as in the first method above, is included in the MC-DCI. When determining whether there is scheduling information for one or more cells regarding which set of cells is indicated through the cell set indicator field in the MC-DCI, the terminal may use a method of interpreting the scheduling cell indicator field or interpreting the FDRA field. In this case, the scheduling cell indicator field that may be included in the MC-DCI is a separate field distinct from the CIF (carrier indication field), or the CIF may replace the scheduling cell indicator field within the MC-DCI. If the terminal is indicated by a cell set that has received upper-layer signaling such as the table above through the cell set indicator field in MC-DCI, the terminal may be indicated by the scheduling cell indicator field regarding the presence or absence of scheduling information for one or more cells. If the terminal is indicated by a cell set that has not set upper-layer signaling such as the table above through the cell set indicator field in MC-DCI, the terminal may be indicated by the FDRA field regarding the presence or absence of scheduling information for one or more cells.

[0242] FIG. 10 illustrates an example in which an MC-DCI according to one embodiment of the present disclosure includes a plurality of FDRA fields.

[0243] Referring to FIG. 10, the MC-DCI (1000) may include a plurality of FDRA fields (1010, 1011, 1012, 1013). Additionally, in one embodiment, there may be a cell corresponding to each FDRA field. That is, when the cells that can be simultaneously scheduled by the MC-DCI (1000) are set to cell 0 (1020), cell 1 (1021), cell 2 (1022), and cell 3 (1023), the MC-DCI (1000) may include an FDRA field (1010) for cell 0, an FDRA field (1011) for cell 1, an FDRA field (1012) for cell 2, and an FDRA field (1013) for cell 3. Whether each cell has been scheduled can be determined based on the value of the FDRA field. Cells scheduled based on the value of the FDRA field can be referred to as actually co-scheduled cells.

[0244] FIG. 11 illustrates an example in which an MC-DCI according to one embodiment of the present disclosure includes at least one of a cell set indicator field, a scheduling cell indicator field, and a plurality of FDRA fields.

[0245] Referring to FIG. 11, the MC-DCI (1100) may include at least one of a cell set indicator field (1101), a scheduling cell indicator field (1102), and a plurality of FDRA fields (1105, 1106, 1107, 1108). As described above, if a terminal receives the MC-DCI within a specific cell and reports to the base station that the number of candidates for a cell set that can be scheduled is two or more, the terminal can expect that the cell set indicator field (1101) exists within the MC-DCI, and if the terminal reports to the base station that there is only one candidate, the field may not exist. FIG. 11 illustrates a case where the terminal reports two candidate cell sets, but cell set 0 (1110) may include three cells: cell 0 (1111), cell 1 (1112), and cell 2 (1113), and cell set 1 (1120) may include cell 3 (1121), cell 4 (1122), cell 5 (1123), and cell 6 (1124). Accordingly, the terminal can expect four FDRA fields to exist within the MC-DCI, which is the maximum value among the number of cells included in each of cell set 0 (1110) and cell set 1 (1120).

[0246] Additionally, FIG. 11 assumes a situation in which the terminal does not receive upper layer signaling such as the table above for cell set 0 (1110). Therefore, as in the second method above, the presence or absence of scheduling information for cells within cell set 0 (1110) can be indicated by the FDRA fields (1105, 1106, 1107, 1108) in MC-DCI. At this time, since there are three cells within cell set 0 (1110), the terminal can be indicated for scheduling information for cell 0 (1111), cell 1 (1112), and cell 2 (1113) through the first, second, and third FDRA fields (1108, 1107, 1106).

[0247] Additionally, the example of FIG. 11 can be understood as an example in which the terminal is assumed to have received upper-layer signaling, such as the table above, for cell set 1 (1120). Accordingly, as in the first method described above, the presence or absence of scheduling information for cells within cell set 1 (1120) can be indicated by the scheduling cell indicator field (1102) in MC-DCI. For example, among all rows in the table set by upper-layer signaling, the terminal can be indicated by the scheduling cell indicator field (1102) in MC-DCI, and the corresponding row can indicate scheduling information for, for example, cell 3 (1121) and cell 5 (1123) within cell set 1 (1120).

[0248] According to one embodiment, the FDRA field may be divided into valid values ​​and invalid values. A valid value may be a case where a frequency domain allocation corresponding to the value of the FDRA field exists. Conversely, an invalid value may be a case where a frequency domain allocation corresponding to the value of the FDRA field does not exist.

[0249] For example, valid and invalid values ​​are described based on FDRA type-0. FDRA type-0 may refer to a method for indicating RBs (or RGBs) that are scheduled based on a bitmap. Here, each bit may have a corresponding RB (or RGB). If the bit is '1', the corresponding RB (or RGB) is scheduled, and if the bit is '0', the corresponding RB (or RGB) is not scheduled. Thus, if at least one bit is '1', it may be determined to be a valid value, and if all bits are '0', it may be determined to be an invalid value.

[0250] For example, valid and invalid values ​​are explained based on FDRA type-1. FDRA type-1 may refer to a method of indicating RBs that are scheduled based on a resource indication value (RIV). Here, FDRA type-1 can schedule consecutive RBs in the frequency domain. FDRA type-1 can indicate the index of the starting RB and the number of consecutive RBs. The RIV value can be one of 0, 1, ..., N*(N+1) / 2 - 1, where N is the number of RBs included in the frequency domain. Therefore, if the RIV value is one of 0, 1, ..., N*(N+1) / 2 - 1, it can be determined as a valid value, and a value greater than or equal to N*(N+1) / 2 can be determined as an invalid value.

[0251] In one embodiment, some of the cells scheduled by MC-DCI may be in the licensed band, and others may be in the unlicensed band (or shared spectrum). For example, in the case of unlicensed band cells, FDRA type-2 may need to be used for uplink scheduling. Specific information regarding FDRA type-2 or examples of its use will be described later.

[0252] The present disclosure may provide a method for determining a cell to be scheduled from a single DCI when a terminal supports multiple cell scheduling with a single DCI.

[0253] According to one embodiment of the present disclosure, a terminal may receive a plurality of Frequency Domain Resource Assignment (FDRA) fields in a single DCI and may determine a cell corresponding to each FDRA field. The terminal may determine whether the cell is scheduled through the FDRA type of the cell and the value of the FDRA field. The terminal may identify whether the cell is scheduled and / or the scheduled cell and / or the unscheduled cell based on one or more of the FDRA type or the FDRA field. For example, the method of interpreting the FDRA field may vary depending on the subcarrier spacing of the corresponding cell.

[0254] According to one embodiment of the present disclosure, when a terminal receives an FDRA type-2 set in a cell, whether the cell is scheduled can be determined based on at least one of the following or a combination of one or more.

[0255] In one embodiment, when a cell has a 15 kHz subcarrier interval, the terminal can determine that the cell is not scheduled if the value of the FDRA field is as follows.

[0256] - The first case is when all bits of the FDRA field are "1".

[0257] - The second case is when the first 6 bits of the FDRA field are all "1". That is, when the 6 MSB (most significant bit) of the FDRA field are all "1".

[0258] - The third case is when all the trailing Y bits in the FDRA field are "1". That is, when all the Y LSB (least significant bit) bits in the FDRA field are "1".

[0259] In one embodiment, when a cell has a 30 kHz subcarrier interval, the terminal can determine that the cell is not scheduled if the value of the FDRA field is as follows.

[0260] - The first case is when the first 5 bits of the FDRA field are all "0" and the subsequent Y bits are all "1". That is, when the 5 MSBs of the FDRA field are all "0" and the Y LSBs are all "1".

[0261] - The second case is when all bits of the FDRA field are "0".

[0262] - The third case is when the first 5 bits of the FDRA field are all "0". That is, when the 5 MSBs of the FDRA field are all "0".

[0263] - The fourth case is when all the trailing Y bits in the FDRA field are "1". That is, when all the Y LSB bits in the FDRA field are "1".

[0264] Each situation is described in more detail below.

[0265] Situation 1. When one cell has a 15kHz subcarrier spacing

[0266] The terminal can check information regarding the subcarrier spacing and FDRA type of each cell included in the set of candidate cells scheduled by MC-DCI. If one of the cells included in the set of candidate cells scheduled by MC-DCI is set to FDRA type-2, the terminal can check whether the subcarrier spacing of the cell is 15 kHz (μ=0) or 30 kHz (μ=1). The present embodiment may be a case where the terminal checks that the subcarrier spacing of the cell is 15 kHz (μ=0).

[0267] FIG. 12 is a drawing illustrating an example of a field indicating frequency domain resource allocation information according to the subcarrier spacing of a cell according to one embodiment of the present disclosure.

[0268] FDRA type-2(a) in Fig. 12 can be understood as an example of a field indicating frequency domain resource allocation information when the cell's subcarrier spacing is 15 kHz.

[0269] Referring to FDRA type-2(a) in FIG. 12, when the subcarrier spacing of the cell is 15 kHz, the length of the field indicating the frequency domain allocation information of the cell within MC-DCI may be 6+Y bits. Here, the 6 bits may indicate the start index (m0) and length (L) of M=10 interlaces included in a single RB-set, and the Y bits indicate the scheduled RB-set. .... Here, Y bits may indicate the index and length of the starting RB set among the RB sets included in the UL BWP. In the present disclosure may be the number of RB-sets set for an indicated active UL BWP. In this disclosure, for convenience, 6 bits and Y bits may be referred to as a RIV scheme (or RIV-like).

[0270] More specifically, 6 bits can be understood through the following example.

[0271] When μ=0, the X=6 Most significant bit of the resource block allocation information (or frequency domain resource allocation information) can represent the set of interlaced indices m0+l allocated to the UE. Here, the indication for the set of interlaced indices consists of a Resource Indication Value (RIV). 0 ≤ RIV <M(M+1) / 2이고 l=0,1, ...,L-1인 경우 리소스 표시 값은 시작 인터레이스 인덱스 m0과 연속적인 인터레이스 인덱스의 수에 해당한다. 리소스 표시 값은 다음과 같이 정의된다

[0272]

[0273] For this, the RIV value can correspond to the starting interlaced index m0 and l value in Table 15 below.

[0274]

[0275] Referring to the RIV formula or Table 15 above, among the RIV values ​​0, 1, ..., M*(M+1) / 2-1=54, the number of start interlaced indices and consecutive interlaced indices may be indicated according to the RIV formula, and subsequently, RIV = M*(M+1) / 2=55, M*(M+1) / 2+1=56, ..., M*(M+1) / 2+7=62 may be indicated according to Table 15, the start interlaced index (m0) and l value. The 6 bits of the RIV value can represent one of the values ​​0, 1, ..., 63, and 0, 1, ..., 62 are values ​​used for scheduling interlacing. However, RIV=63 (6 bits in binary is '111111') may not be used. In other words, there may not be a scheduled interlaced corresponding to the above value (RIV=63). Therefore, using the above value (RIV=63 (6 bits in binary is '111111')), an unscheduled cell can be indicated.

[0276] More specifically, Y bits can be understood as the following example.

[0277] In one embodiment, when μ=0 to μ=1, the resource block allocation information (or frequency domain resource allocation information) The LSB (least significant bit) indicates a consecutive set of RBs to the terminal. For example, Y bits may exist in DCI format 0_1. The resource allocation field is the resource indication value ( It consists of ). 0≤ , l=0,1,...,L RBset For -1, the resource reference value is the start RB set index ( and the number of consecutive RB sets (L RB-set It indicates ). Resource reference values ​​are defined as follows.

[0278]

[0279] Various embodiments of the present disclosure will be described with reference to the formula.

[0280] In one embodiment, when one RB-set is included in the UL BWP ( , Y=0 bits (Y=0). Therefore, if Y=0 bits, a cell that is not scheduled with the above Y bits may not be indicated.

[0281] In one embodiment, when two RB-sets are included in the UL BWP ( , Y=2 bits (Y=2). Here =0, 1, 2 can be used to indicate the starting RB set index and the number of consecutive RB sets. Y bits can have values ​​of 0, 1, ..., 3. Therefore, there may not be a scheduled RB-set corresponding to Y bits 3 (both bits are '11'. binary 2 bits are '11'). Therefore, using the above value (3 (binary 2 bits are '11')), an unscheduled cell can be indicated.

[0282] In one embodiment, when three RB-sets are included in the UL BWP ( , Y=3 bits (Y=3). Here =0,1,2,3,4,5 can be used to indicate the starting RB set index and the number of consecutive RB sets. Y bits can have values ​​of 0, 1,..., 7. Therefore, there may not be a scheduled RB-set corresponding to Y bits 7 (all 3 bits are '111'. In binary, 3 bits are '111'). Therefore, using the above value (7 (in binary, 3 bits are '111')), an unscheduled cell can be indicated.

[0283] In one embodiment, when four RB-sets are included in the UL BWP ( , Y=4 bits (Y=4). Here =0,1,...,9 is used to indicate the starting RB set index and the number of consecutive RB sets. Y bits can have values ​​of 0, 1,..., 15. Therefore, there may not be a scheduled RB-set corresponding to Y bits 15 (all 4 bits are '1111'. In binary, 4 bits are '1111'). Therefore, using the above value (15 (in binary, 4 bits are '1111')), an unscheduled cell may be indicated.

[0284] In one embodiment, when 5 RB-sets are included in the UL BWP ( , Y=4 bits (Y=4). Here =0,1,...,14 is used to indicate the starting RB set index and the number of consecutive RB sets. Y bits can have values ​​of 0, 1,...,15. Therefore, there may not be a scheduled RB-set corresponding to Y bits 15 (all 4 bits are '1111'. In binary, 4 bits are '1111'). Therefore, using the above value (15 (in binary, 4 bits are '1111')), an unscheduled cell may be indicated.

[0285] In summary, among the sizes of Y bits, excluding the case where Y=0, if all Y bits are '1', an unscheduled cell may be indicated. That is, if all bits included in the Y LSB of the FDRA are '1', an unscheduled cell may be indicated.

[0286] In one embodiment of the present disclosure, a method for indicating that a cell having a 15 kHz subcarrier spacing is not scheduled may include one of the following or a combination of at least one of the following. In a method for indicating that a cell having a 15 kHz subcarrier spacing is not scheduled, the FDRA field may mean a field corresponding to the cell having the 15 kHz subcarrier spacing. Additionally, the FDRA type may include FDRA type-2.

[0287] In one embodiment, as a first method indicating that a cell with a 15 kHz subcarrier spacing is not scheduled, the terminal can determine whether the cell is scheduled based on all bits (6+Y bits) of the FDRA field. For example, if all bits of the FDRA field are '1', the terminal can determine that the cell is not scheduled. Here, the FDRA field may include 6 bits MSB and Y bits LSB. Accordingly, the terminal can determine that the cell with a 15 kHz subcarrier spacing corresponding to the FDRA field is not scheduled if all bits are '1' based on the total 6+Y bits (if the bit values ​​of the bits included in the 6+Y bits are all 1). For example, if all 6 bits MSB are '1' and the remaining Y bits LSB are not all '1' (if the bit values ​​of the bits included in the 6 MSB are all 1 and at least some of the bit values ​​of the bits included in the Y LSB are 0, or if the bit values ​​of the bits included in the 6 MSB are all 1 and the bit values ​​of the bits included in the Y LSB are all 0), the terminal can determine that the DCI format containing the above information is an error case. Alternatively, if all of the Y bits LSB are '1' and the remaining 6 bits MSB are not all '1' (where the bit values ​​of all bits included in the Y LSB are 1 and at least some of the bit values ​​of the 6 MSB are 0, or where all of the bit values ​​included in the Y LSB are 1 and all of the bit values ​​included in the 6 MSB are 0), the terminal may determine that the DCI format containing the above information is an error case. If the terminal determines that it is an error case, it may discard (or ignore) the information indicated by the DCI format without applying it.When the terminal determines an error case, among the information indicated by the DCI format, the information regarding the cell (the cell corresponding to the FDRA field determined as an error case) is not applied and is discarded, while the information regarding the remaining cells (the remaining cells excluding the cell corresponding to the FDRA field determined as an error case) may be applied.

[0288] In one embodiment, as a second method indicating that a cell with a 15 kHz subcarrier spacing is not scheduled, the terminal can determine whether the cell is scheduled based only on the 6-bit MSB of the FDRA field. The terminal can identify whether the cell is scheduled through the 6 MSB of the FDRA field. For example, if all bits of the 6-bit MSB of the FDRA field are '1' (if the bit value of all bits included in the 6 MSB is 1), the terminal can determine that the cell (the cell corresponding to the FDRA field) is an unscheduled cell. Accordingly, the terminal can determine that the cell with a 15 kHz subcarrier spacing corresponding to the FDRA field is not scheduled if all bits are '1' based on the total 6-bit MSB. For example, in this case, the bits of the Y-bit LSB may not provide information. That is, the scheduling status of the cell can be determined based on the 6-bit MSB regardless of the value of the Y-bit LSB. For example, the Y bits LSB may be discarded, ignored, or not included in the FDRA field (e.g., Y=0).

[0289] In one embodiment, as a third method indicating that a cell with a 15 kHz subcarrier spacing is not scheduled, the terminal can determine whether the cell is scheduled based solely on the Y bits LSB of the FDRA field. The terminal can identify whether the cell is scheduled through the Y LSB of the FDRA field. For example, if all bits of the Y bits LSB of the FDRA field are '1' (if the bit value of all bits included in the Y LSB is 1), the terminal can determine that the cell (the cell corresponding to the FDRA field) is an unscheduled cell. Accordingly, the terminal can determine that the cell with a 15 kHz subcarrier spacing corresponding to the FDRA field is not scheduled if all bits are '1' based on the total Y bits LSB. For example, in this case, the bits of the 6 bits MSB may not provide information. That is, the scheduling status of the cell can be determined based on the Y bits LSB regardless of the value of the 6 bits MSB. For example, the 6 bits MSB may be discarded, ignored, or not included in the FDRA field.

[0290] According to one embodiment, the third method may be used when Y > 0. If Y = 0, the second method may be used. That is, the second and third methods may be selectively used based on the value of Y. That is, the method to be used by the terminal may be determined based on the value of Y (the bit size of the Y LSB of the FDRA field).

[0291] Situation 2: When one cell has a 30kHz subcarrier spacing

[0292] According to one embodiment, a terminal can check information regarding the subcarrier spacing and FDRA type of each cell included in the set of candidate cells scheduled by MC-DCI. If one of the cells included in the set of candidate cells scheduled by MC-DCI is set to FDRA type-2, the terminal can check whether the subcarrier spacing of the cell is 15 kHz (μ=0) or 30 kHz (μ=1). This embodiment may correspond to the case where the terminal checks that the subcarrier spacing of the cell is 30 kHz (μ=1).

[0293] Figure 12 (b) FDRA type-2 illustrates an example of a field indicating frequency domain resource allocation information when the cell's subcarrier spacing is 30 kHz.

[0294] Referring to FDRA type-2 in Fig. 12(b), when the cell's subcarrier spacing is 30 kHz, the length of the field indicating the frequency domain allocation information of the cell within MC-DCI may be 5+Y bits. Here, the 5 bits can indicate, via a bitmap, whether M=5 interlaces included in a single RB-set are scheduled. That is, each of the 5 bits can be used to indicate whether a single interlace is scheduled. Here, the interlace corresponding to the bit with a value of '1' among the 5 bits can be determined to be scheduled. The interlace corresponding to the bit with a value of '0' among the 5 bits can be determined not to be scheduled. The Y bits indicate the scheduled RB-set, and .... Here, Y bits may indicate the index and length of the starting RB set among the RB sets included in the UL BWP. In the present disclosure may be the number of RB-sets set for an indicated active UL BWP. In this disclosure, for convenience, 5 bits may be referred to as a bitmap method and Y bits as a RIV method (or RIV-like).

[0295] In one embodiment, the 5 bits may indicate a scheduled interlace based on a bitmap format. The terminal may identify the bit corresponding to '1' among the 5 bits. Based on identifying the bit corresponding to the value of '1', the terminal may determine that the interlace corresponding to '1' is scheduled. That is, the terminal may determine that the interlace corresponding to the bit with a value of '1' among the 5 bits is scheduled. In one embodiment, if all 5 bits are '0', there may be no scheduled interlace. Therefore, if all 5 bits are '0', the terminal may determine that the cell is not scheduled.

[0296] Since the Y bits in Situation 2 correspond to the Y bits of Example 1 described above, the description is omitted to avoid redundancy, and the Y bits in Situation 2 can be understood in correspondence with the description of the Y bits in Situation 1 described above.

[0297] In one embodiment, the FDRA field of a cell with a 30 kHz subcarrier spacing may include 5+Y bits. The 5 bits MSB may indicate an interlace scheduled within an RB set in a bitmap manner. The Y bits LSB may indicate RB sets scheduled in a RIV manner. Accordingly, the scheduling status of the cell can be determined based on the values ​​of the 5 bits MSB and the Y bits LSB.

[0298] In the present disclosure, a method for indicating that a cell with a 30 kHz subcarrier spacing is not scheduled may be one of the following or a combination of at least one of them. In a method for indicating that a cell with a 30 kHz subcarrier spacing is not scheduled, the FDRA field may mean a field corresponding to a cell with a 30 kHz subcarrier spacing. Additionally, the FDRA type may correspond to FDRA type-2.

[0299] According to one embodiment, in a first method for indicating that a cell having a 30 kHz subcarrier spacing is not scheduled, a terminal can determine whether the cell is scheduled based on all bits (5+Y bits) of an FDRA field. For example, if all bits of the FDRA field are '0', the terminal can determine that the cell having the 30 kHz subcarrier spacing is an unscheduled cell. Here, the FDRA field may include 5 bits MSB and Y bits LSB. Accordingly, the terminal can determine that the cell having the 30 kHz subcarrier spacing corresponding to the FDRA field is not scheduled if all bits are '0' based on a total of 5+Y bits (if the bit values ​​of all bits included in the 5+Y bits are all 0). For example, if all Y bits LSB are '0', According to the formula, a corresponding value may exist. However, since the 5 bits MSB are all '0', the RB set indicated by the Y bits LSB may not be used as information regarding scheduling. That is, since it is determined that there is no scheduled interlace because the 5 bits MSB are all '0', the RB set corresponding to the Y bits LSB may be ignored.

[0300] According to one embodiment, in a second method for indicating that a cell having a 30 kHz subcarrier spacing is not scheduled, the terminal can determine whether the cell is scheduled based only on the 5 bits MSB of the FDRA field. The terminal can identify whether the cell is scheduled through the 5 MSB of the FDRA field. For example, if all bits of the 5 bits MSB of the FDRA field are '0' (if the bit value of all bits included in the 5 MSB is 1), the terminal can determine that the cell (the cell corresponding to the FDRA field) is not scheduled. Therefore, the terminal can determine that the cell with a 30 kHz subcarrier spacing corresponding to the FDRA field is not scheduled if all bits are '0' based on the total 5 bits MSB. For example, in this case, the bits of the Y bits LSB may not provide information. That is, the scheduling status of the cell can be determined based on the 5 bits MSB regardless of the value of the Y bits LSB. For example, the Y bits LSB may be discarded, ignored, or not included in the FDRA field (e.g., Y=0).

[0301] According to one embodiment, a third method for indicating that a cell having a 30 kHz subcarrier spacing is not scheduled allows the terminal to determine whether the cell is scheduled based solely on the Y bits LSB of the FDRA field. The terminal can identify whether the cell is scheduled through the Y LSB of the FDRA field. For example, if all bits of the Y bits LSB of the FDRA field are '1' (if the bit value of all bits included in the Y LSB is 1), the terminal can determine that the cell (the cell corresponding to the FDRA field) is not scheduled. Therefore, the terminal can determine that the cell with a 30 kHz subcarrier spacing corresponding to the FDRA field is not scheduled if all bits are '1' based on the total Y bits LSB. For example, in this case, the bits of the 5 bits MSB may not provide information. That is, the terminal can determine whether the cell is scheduled based on the Y bits LSB regardless of the value of the 5 bits MSB. For example, the 5 bits MSB may be discarded, ignored, or not included in the FDRA field.

[0302] According to one embodiment, a second method or a third method may be optionally used based on the value of Y. For example, the third method may be used when Y > 0. For example, the second method may be used when Y = 0. That is, the terminal may optionally use the second method or the third method based on the value of Y (bit size of the Y LSB of the FDRA field).

[0303] Hereinafter, with reference to FIGS. 13 and 14, a method for transmitting and receiving a demodulation reference signal in a wireless communication system according to various embodiments of the present disclosure will be described in detail. The contents of the present disclosure may be applied to FDD (frequency division duplex), TDD (time division duplex) and / or XDD (cross division duplex) (and / or SBFD (subband non-overlapping full duplex), full duplex) systems. Hereinafter, in the present disclosure, upper signaling, or upper layer signaling, may refer to a signal transmission method 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. In addition, such upper layer signaling may include RRC signaling, PDCP signaling, or a MAC (medium access control) control element (MAC CE).

[0304] Hereinafter, in the present disclosure, a terminal may use various methods to determine whether cooperative communication is applied. For example, the PDCCH(s) that assign the PDSCH to which cooperative communication is applied may have a specific format, the PDCCH(s) that assign the PDSCH to which cooperative communication is applied may include a specific indicator indicating whether cooperative communication is applied, the PDCCH(s) that assign the PDSCH to which cooperative communication is applied may be scrambled with a specific RNTI, or cooperative communication may be assumed to be applied in a specific section indicated to an upper layer. Hereinafter, in the present disclosure, for convenience of explanation, the reception of a PDSCH to which cooperative communication is applied by a terminal based on conditions similar to those described above may be referred to as an NC-JT case.

[0305] In describing the present disclosure below, the term "upper layer signaling" may mean a signaling corresponding to at least one or a combination of at least one of the following signalings.

[0306] - MIB (Master Information Block)

[0307] - SIB (System Information Block) or SIB

[0308] - RRC (Radio Resource Control)

[0309] - MAC (Medium Access Control) CE (Control Element)

[0310] In addition, L1 signaling may be a signaling corresponding to at least one or a combination of at least one of the following physical layer channels or signaling methods using signaling.

[0311] - PDCCH (Physical Downlink Control Channel)

[0312] - DCI (Downlink Control Information)

[0313] - Terminal-specific (UE-specific) DCI

[0314] - Group common DCI

[0315] - Common DCI

[0316] - Scheduling DCI (e.g., DCI used for the purpose of scheduling downlink or uplink data)

[0317] - Non-scheduling DCI (e.g., DCI not intended for scheduling downlink or uplink data)

[0318] - PUCCH (Physical Uplink Control Channel)

[0319] - UCI (Uplink Control Information)

[0320] In the following disclosure, determining the priority between A and B may be referred to in various ways, such as selecting the one with the higher priority according to a predetermined priority rule and performing the corresponding action, or omitting or dropping the action for the one with the lower priority.

[0321] In the following disclosure, the examples are described through a number of embodiments, but these are not independent, and one or more embodiments may be applied simultaneously or in combination.

[0322] [DMRS Related]

[0323] Next, the antenna port field indications included in DCI format 1_1 and DCI format 1_2, as defined in Table 13 above, will be described. The antenna port fields in DCI formats 1_1 and 1_2 can be represented by 4, 5, or 6 bits and can be indicated through the following Tables 16-1 through 16-8. The indications of the antenna port fields can be identified based on the following Tables 16-1 through 16-8.

[0324]

[0325]

[0326]

[0327]

[0328]

[0329]

[0330]

[0331] [Table 16-1] and [Table 16-2] can be used when dmrs-type is 1 and maxLength is 1. [Table 16-3] and [Table 16-4] can be used when dmrs-Type=1 and maxLength=2. [Table 16-5] and [Table 16-6] can indicate the DMRS ports used when dmrs-type=2 and maxLength=1. [Table 16-7] and [Table 16-8] can indicate the DMRS ports used when dmrs-type is 2 and maxLength is 2. The indication (bit) of the antenna port field may be determined according to [Table 16-1] or [Table 16-2] when dmrs-type is 1 and maxLength is 1, according to [Table 16-3] or [Table 16-4] when dmrs-Type=1 and maxLength=2, according to [Table 16-5] or [Table 16-6] when dmrs-type=2 and maxLength=1, and according to [Table 16-7] or [Table 16-8] when dmrs-type is 2 and maxLength is 2. In the present disclosure, being indicated by using a specific table may mean that the indication (bit) is determined according to a specific table or a relationship defined by a specific table.

[0332] In one embodiment, when a terminal receives a MAC-CE that activates a code point indicating two TCI states for at least one code point in the TCI state field within the DCI, the terminal may be indicated to a DMRS port using [Table 16-2], [Table 16-4], [Table 16-6], and [Table 16-8]. When a terminal does not receive a MAC-CE that activates a code point indicating two TCI states for at least one code point in the TCI state field within the DCI, the terminal may be indicated to a DMRS port using [Table 16-1], [Table 16-3], [Table 16-5], and [Table 16-7]. When a terminal is instructed with code points indicating two TCI states through the TCI state field, the terminal may be instructed with entries indicating DMRS ports 1000, 1002, and 1003 for NC-JT scheduling purposes in [Table 16-2], [Table 16-4], [Table 16-6], and [Table 16-8]. The entries indicating ports 1000, 1002, and 1003 may correspond to entry 12 in [Table 16-2], entry 31 in [Table 16-4], entry 24 in [Table 16-6], and entry 58 in [Table 16-8].

[0333] In one embodiment, for DCI format 1_1, if the terminal is configured with both upper layer signalings dmrs-DownlinkForPDSCH-MappingTypeA and dmrs-DownlinkForPDSCH-MappingTypeB, the bit length of the Antenna port field in DCI format 1_1 is max{x A , x B It can be determined as}. Here, x A w x Bcan represent the bit length of the Antenna port field determined by dmrs-DownlinkForPDSCH-MappingTypeA and dmrs-DownlinkForPDSCH-MappingTypeB, respectively. x A w x B If the PDSCH mapping type corresponding to the smaller value is scheduled, |x A -x B | As many MSB (most significant bit) bits as there are bits, they can be allocated as 0 bits and transmitted.

[0334] In one embodiment, for DCI format 1_2, if the terminal does not receive the upper layer signaling antennaPortsFieldPresenceDCI-1-2, the antenna port field may not exist in DCI format 1_2. That is, if the terminal does not receive the upper layer signaling antennaPortsFieldPresenceDCI-1-2, the length of the antenna port field may be 0 bits, and the terminal can determine the DMRS port by assuming the 0th entry of [Table 16-1], [Table 16-3], [Table 16-5], and [Table 16-7]. If the terminal receives the upper layer signaling antennaPortsFieldPresenceDCI-1-2, the bit length of the antenna port field in DCI format 1_2 may be determined similarly to the case of DCI format 1_1 described above. If the terminal is configured with both upper-layer signalings dmrs-DownlinkForPDSCH-MappingTypeA-DCI-1-2 and dmrs-DownlinkForPDSCH-MappingTypeB-DCI-1-2, the bit length of the Antenna port field within DCI format 1_2 is max{x A , x B It can be determined as}. Here, x A w xB can represent the bit length of the antenna port field determined by dmrs-DownlinkForPDSCH-MappingTypeA-DCI-1-2 and dmrs-DownlinkForPDSCH-MappingTypeB-DCI-1-2, respectively. x A w x B If the PDSCH mapping type corresponding to the smaller value is scheduled, |x A -x B | The number of MSB bits can be allocated as 0 bits and transmitted.

[0335] In [Table 16-1] through [Table 16-8], the numbers 1, 2, and 3 indicated by "Number of DMRS CDM group(s) without data" may represent CDM (code division multiplexing) groups {0}, {0, 1}, and {0, 1, 2}, respectively. DMRS port(s) can be understood as sequentially listing the indices of the ports in use. Antenna port may be indicated as DMRS port + 1000. The DMRS CDM group may be connected to the method of generating the DMRS sequence and the antenna port as shown in [Table 17-1] and [Table 17-2]. [Table 17-1] shows the parameters when using dmrs-type=1, and [Table 17-2] shows the parameters when using dmrs-type=2.

[0336]

[0337]

[0338] According to one embodiment, the sequence of DMRS according to each parameter can be determined by the following Equation 2. In Equation 2, p may represent a DMRS port. k may represent a subcarrier index. l may represent an OFDM symbol index. μ may represent a subcarrier spacing. w f (k') and w t (l') may represent the FD-OCC (frequency domain orthogonal cover code) and TD-OCC (time domain orthogonal cover code) coefficients according to the k' and l' values, respectively. can correspond to the spacing between CDM groups expressed as the number of subcarriers. In [Equation 2] can mean a scaling factor representing the ratio between the EPRE (energy per RE) of PDSCH and the EPRE of DMRS. It can be calculated as follows. When the number of CDM groups is 1, 2, or 3, The values ​​of can be 0 dB, -3 dB, and -4.77 dB, respectively.

[0339] [Mathematical Formula 2]

[0340]

[0341] According to one embodiment, the position of the DM-RS symbol is and interval and may be expressed by the following [Table 18-1] to [Table 18-2]. In the case of PDSCH mapping type A, It can correspond to the interval between the first OFDM symbol of the slot and the last OFDM symbol of the scheduled PDSCH resource within the slot. In the case of PDSCH mapping type B, It can correspond to a scheduled PDSCH resource interval.

[0342]

[0343]

[0344] According to one embodiment, a time domain index The supported antenna port p can be expressed as described in [Table 18-3]. If the upper layer parameter maxLength is not set in DMRS-DownlinkConfig, a single-symbol DM-RS may be used. Additionally, if the upper layer parameter maxLength in DMRS-DownlinkConfig is equal to len2, the single-symbol or double-symbol DM-RS may be determined by the associated DCI.

[0345]

[0346] In one embodiment, when DMRS type 1 is used, if the terminal is scheduled a single codeword using [Table 16-1] and [Table 16-3] and is instructed to entries 2, 9, 10, 11, and 30, or is scheduled a single codeword using [Table 16-2] and is instructed to entries 2, 9, 10, 11, and 12, or is scheduled a single codeword using [Table 16-4] and is instructed to entries 2, 9, 10, 11, 30, and 31, or is scheduled two codewords, the terminal may be considered as single-user MIMO (SU-MIMO, single-user MIMO) scheduling. That is, the terminal may assume that no other terminal is scheduled on any remaining orthogonal DMRS ports other than the DMRS port assigned to the scheduled PDSCH, and may not expect multi-user MIMO (MU-MIMO) scheduling. In this case, the terminal may not assume that other terminals are co-scheduled and may not perform multi-user MIMO reception operations such as cancellation, nulling, or whitening.

[0347] In one embodiment, where DMRS type 2 is used, if a terminal is scheduled with a single codeword using [Table 16-5] and [Table 16-7] and is instructed to entries 2, 10, and 23, or is scheduled with a single codeword using [Table 16-6] and is instructed to entries 2, 10, 23, and 24, or is scheduled with a single codeword using [Table 16-8] and is instructed to entries 2, 10, 23, and 58, or is scheduled with two codewords, the terminal may be considered to have single-user MIMO scheduling. That is, the terminal may assume that no other terminal is scheduled on any orthogonal DMRS ports other than the DMRS port assigned to the scheduled PDSCH. In this case, the terminal may not expect multi-user MIMO scheduling. In such cases, the terminal may not perform multi-user MIMO reception operations, such as cancellation, nulling, or whitening, without assuming that another terminal is co-scheduled.

[0348] According to one embodiment, the terminal may not expect that the maximum number of front-loaded DMRS symbols is set to len2 through the upper layer signaling maxLength, while more than one additional DMRS symbol is set through the upper layer signaling dmrs-AdditionalPosition.

[0349] According to one embodiment, for all terminals scheduled for multi-user MIMO, the terminal may not expect the actual number of front-loaded DMRS symbols, the actual number of additional DMRS symbols, the DMRS symbol location, and the DMRS type setting to be different.

[0350] According to one embodiment, for a terminal with a PRG (precoding resource block group) size of 2 or 4, for other terminals co-scheduled using other DMRS ports orthogonal within the same CDM group as the DMRS port assigned to the terminal, it may not be expected that frequency resource allocation will not match in the PRG unit grid.

[0351] According to one embodiment, in the case of a PDSCH scheduled in DCI formats 1_1 and 1_2, the terminal may include DMRS ports assigned to other terminals that can be co-scheduled via a multi-user MIMO method with CDM groups indicated by the column "Number of DMRS CDM group(s) without data" in [Tables 16-1] to [Tables 16-8]. Additionally, it may be assumed that the terminal may not be used for data transmission purposes. The meaning that the values ​​indicated by the column "Number of DMRS CDM group(s) without data" in [Tables 16-1] to [Tables 16-8] are 1, 2, and 3 can be understood as the indices of the CDM groups corresponding to the meaning described above corresponding to CDM groups 0, {0,1}, and {0,1,2}, respectively.

[0352] According to one embodiment, when a terminal receives the upper layer signaling dmrs-FD-OCC-disableForRank1PDSCH and the terminal is assigned one DMRS port for PDSCH scheduling, the terminal may not expect that another DMRS port using FD-OCC among other orthogonal DMRS ports belonging to the same CDM group as the assigned DMRS port will be assigned to another terminal.

[0353] Next, the antenna port field indications included in DCI format 0_1 ​​and DCI format 0_2, as defined in [Table 5] above, will be described. The antenna port fields in DCI format 0_1 ​​and 0_2 can be represented by 3, 4, or 5 bits and can be indicated by the following [Tables 16-9] through [Table 16-24]. The indications of the antenna port fields can be identified according to the following [Tables 16-9] through [Table 16-24].

[0354]

[0355]

[0356]

[0357]

[0358]

[0359]

[0360]

[0361]

[0362]

[0363]

[0364]

[0365]

[0366]

[0367]

[0368]

[0369]

[0370] Tables 16-9 through 16-12 may be used when dmrs-type is 1 and maxLength is 1. Tables 16-13 through 16-16 may be used when dmrs-Type=1 and maxLength=2. Tables 16-17 through 16-20 may indicate the DMRS port used when dmrs-type=2 and maxLength=1. Tables 16-21 through 16-24 may indicate the DMRS port used when drms-type is 2 and maxLength is 2. The indication (bit) of the antenna port field may be determined according to at least one of Tables 16-9 through 16-12 when dmrs-type is 1 and maxLength is 1. The indication (bit) of the antenna port field can be determined according to at least one of [Table 16-13] to [Table 16-16] when dmrs-Type=1 and maxLength=2. The indication (bit) of the antenna port field can be determined according to at least one of [Table 16-17] to [Table 16-20] when dmrs-type=2 and maxLength=1. The indication (bit) of the antenna port field can be determined according to at least one of [Table 16-21] to [Table 16-24] when dmrs-type is 2 and maxLength is 2.

[0371] According to one embodiment, in DCI format 0_1, when the terminal is configured with both upper layer signalings dmrs-UplinkForPUSCH-MappingTypeA and dmrs-UplinkForPUSCH-MappingTypeB, the bit length of the Antenna port field in DCI format 0_1 ​​is max{x A , x B It can be determined as}. Here, x A w x Bcan represent the bit length of the Antenna port field determined by dmrs-UplinkForPUSCH-MappingTypeA and dmrs-UplinkForPUSCH-MappingTypeB, respectively. x A w x B If the PUSCH mapping type corresponding to the smaller of the two values ​​is scheduled, |x A -x B | The number of MSB bits can be allocated as 0 bits and transmitted.

[0372] According to one embodiment, in DCI format 0_2, if the terminal does not receive the upper layer signaling antennaPortsFieldPresenceDCI-0-2, the DCI format 0_2 may not have an antenna port field. That is, in such cases, the length of the antenna port field may be 0 bits. The terminal may determine the DMRS port by assuming the 0th entry of [Table 16-9] to [Table 16-24]. If the terminal receives the upper layer signaling antennaPortsFieldPresenceDCI-0-2, the bit length of the antenna port field within DCI format 0_2 may be determined similarly to the case of the DCI format 0_1 ​​described above. If the terminal is configured with both upper layer signalings dmrs-UplinkForPUSCH-MappingTypeA-DCI-0-2 and dmrs-UplinkForPUSCH-MappingTypeB-DCI-0-2, the bit length of the Antenna port field within DCI format 0_2 is max{x A , x B It can be determined as}. Here, x A w x Bcan represent the bit length of the antenna port field determined by dmrs-UplinkForPUSCH-MappingTypeA-DCI-0-2 and dmrs-UplinkForPUSCH-MappingTypeB-DCI-0-2, respectively. x A w x B If the PDSCH mapping type corresponding to the smaller value is scheduled, |x A -x B | The number of MSB bits can be allocated as 0 bits and transmitted.

[0373] According to one embodiment, the numbers 1, 2, and 3 indicated by "Number of DMRS CDM group(s) without data" in [Tables 16-9] to [Table 16-24] may represent CDM groups {0}, {0, 1}, and {0, 1, 2}, respectively. DMRS port(s) can be understood as listing the indices of the ports in use in order. An antenna port may be indicated as DMRS port + 1000. The CDM group of the DMRS is connected to the antenna port and the method of generating the DMRS sequence as shown in [Table 17-1a] and [Table 17-2a]. [Table 17-1a] may correspond to the parameters when using dmrs-type=1. [Table 17-2a] may correspond to the parameters when using dmrs-type=2.

[0374]

[0375]

[0376] According to one embodiment, the sequence of DMRS according to each parameter can be determined by the following Equation 2-1. Equation 2-1 can be understood as an example of the case where transmission precoding is not enabled. In Equation 2-1, can refer to the DMRS port. k can refer to the subcarrier index. l can refer to the OFDM symbol index. μ can refer to the subcarrier spacing. w f (k') and w t (l') may represent the FD-OCC (frequency domain orthogonal cover code) and TD-OCC (time domain orthogonal cover code) coefficients according to the k' and l' values, respectively. represents the spacing between CDM groups in terms of the number of subcarriers. In [Equation 2-1] is a scaling factor representing the ratio between PUSCH's EPRE (energy per RE) and DMRS's EPRE, and It can be calculated as follows, depending on whether the number of CDM groups is 1, 2, or 3 The values ​​of can be 0 dB, -3 dB, and -4.77 dB, respectively.

[0377] [Mathematical Formula 2-1]

[0378]

[0379] In mathematical formula 2-1 can mean the number of transmission layers. According to Equation 2-1, the intermediate quantity It can be precoded by a precoding matrix W, multiplied by a scaling factor, and mapped to a physical resource. and can mean an antenna port. Resource element It may be included within a common resource block allocated for PUSCH transmission.

[0380] According to one embodiment, the position of the DM-RS symbol is and interval and may be given as shown in [Table 19-1] to [Table 19-3] below. Specifically, in the case where intra-slot frequency hopping is not used, for PUSCH mapping type A, is the interval between the first OFDM symbol of the slot and the last OFDM symbol of the scheduled PUSCH resource within the slot, which may follow Tables 19-1 to 19-2. When intra-slot frequency hopping is not used, for PDSCH mapping type B, is an interval of scheduled PDSCH resources, which may follow Tables 19-1 to 19-2. When intra-slot frequency hopping is used, is the duration per hop, and can follow Table 19-3.

[0381]

[0382]

[0383]

[0384] In one embodiment, the time domain index The supported antenna port p can be given according to [Table 19-4].

[0385]

[0386] In one embodiment, when frequency hopping is not used, the terminal may assume that the upper layer signaling dmrs-AdditionalPosition is set to 'pos2'. In this case, up to two additional DMRS symbols may be used for PUSCH transmission. When frequency hopping is used, the terminal may assume that the upper layer signaling dmrs-AdditionalPosition is set to 'pos1'. In this case, up to one additional DMRS symbol may be used for PUSCH transmission.

[0387] According to one embodiment, in the case of a PUSCH scheduled with DCI format 0_1 ​​and 0_2, the terminal may include a DMRS port assigned to another terminal that can be co-scheduled via a multi-user MIMO method with CDM groups indicated by the column "Number of DMRS CDM group(s) without data" in [Table 16-9] to [Table 16-24]. It may be assumed that the terminal may not be used for data transmission purposes, and the meaning that the values ​​indicated by the column "Number of DMRS CDM group(s) without data" in [Table 16-9] to [Table 16-24] are 1, 2, and 3 can be understood as the indices of the CDM groups corresponding to the meaning described above corresponding to CDM groups 0, {0,1}, and {0,1,2}, respectively.

[0388] <First Embodiment: Enhanced DMRS type 1 and 2 support method supporting an increased number of orthogonal ports>

[0389] In one embodiment of the present disclosure, a method for supporting enhanced DMRS type 1 and 2 that supports an increased number of orthogonal ports is described. The present embodiment may operate in combination with other embodiments.

[0390] According to one embodiment, a relatively advanced specification of a 5G communication system can support an enhanced DMRS type 1 and DMRS type 2 that support an increased number of orthogonal ports while maintaining the same resource element (RE) usage and overhead compared to the DMRS type 1 and DMRS type 2 supported in the initial specification of the 5G communication system for both uplink and downlink.

[0391] Generally, for the existing DMRS type 1, up to 4 and 8 orthogonal DMRS ports can be supported when the number of front-loaded symbols is 1 and 2, respectively, and for the DMRS type 2, up to 6 and 12 orthogonal DMRS ports can be supported when the number of front-loaded symbols is 1 and 2, respectively. Starting from these support specifications, for the enhanced DMRS type 1, up to 8 and 16 orthogonal DMRS ports can be supported when the number of front-loaded symbols is 1 and 2, respectively, and for the enhanced DMRS type 2, up to 12 and 24 orthogonal DMRS ports can be supported when the number of front-loaded symbols is 1 and 2, respectively. In the description of the present disclosure, a new DMRS type supporting such an increased number of orthogonal ports may be referred to as "enhanced DMRS type 1 and 2," "new DMRS type 1 and 2," "new DMRS type 1 and 2," "DMRS type 1-1 and 2-1," or "DMRS type 3 and 4." Additionally, similar extended names that may be used to indicate enhanced functionality over existing DMRS types 1 and 2 may not be excluded. Although the following description focuses on downlinks, the present disclosure may similarly apply to uplink DMRS support.

[0392] In one embodiment, if the terminal supports enhanced DMRS type 1 and 2, the terminal may report its terminal capability to the base station that it supports enhanced DMRS type 1 and 2. In this case, the terminal capability report may be transmitted to the base station on a per-band basis. Alternatively, the terminal capability report may be transmitted more specifically on a per-FS (feature set) or per-FSPC (feature set per component carrier) basis. Additionally, the terminal capability report may be supported differently by frequency range (FR). For example, the terminal capability report may be limited to FR1 only. For example, the terminal capability report may be reported per frequency range (FR) and / or reported for FR1. Furthermore, as described above, in the case of enhanced DMRS type 1, up to 8 and 16 orthogonal DMRS ports may be supported when the number of front-loaded symbols is 1 and 2, respectively. Additionally, the terminal capability report may include meaning (information) that, in the case of enhanced DMRS type 2, it can support up to 12 and 24 orthogonal DMRS ports, respectively, when the number of front-loaded symbols is 1 and 2. The terminal may report through a common terminal capability for enhanced DMRS type 1 and 2. In this case, the terminal may report to the base station whether it supports only enhanced DMRS type 1, only enhanced DMRS type 2, and / or both enhanced DMRS type 1 and 2. Additionally, the terminal may report to the base station, through individual terminal capabilities, whether it supports enhanced DMRS type 1 and 2, respectively.

[0393] According to one embodiment, if a terminal supports a dynamic switching function between an enhanced DMRS type and an existing DMRS type, the terminal may report the said dynamic switching function to the base station through a terminal capability. Here, the dynamic switching function between the existing type and the enhanced type may mean that a change is possible via MAC-CE for the DMRS type set through upper layer signaling, or that a selection between the existing type and the enhanced type is possible via DCI, or both. If the terminal reports whether it supports enhanced DMRS type 1 and 2 through a common terminal capability, the terminal may report whether it supports a dynamic switching function for DMRS type 1 and 2 as a single terminal capability, and may report whether it supports only dynamic switching for DMRS type 1 and enhanced DMRS type 1, whether it supports only dynamic switching for DMRS type 2 and enhanced DMRS type 2, and / or whether both types support dynamic switching between the existing type and the enhanced type. Alternatively, if the terminal reports whether it supports enhanced DMRS type 1 and 2 through a common terminal capability or through an individual terminal capability, it may report that dynamic switching between the existing type and the enhanced type is possible through an individual terminal capability for each type.

[0394] According to one embodiment, when a terminal operates as an enhanced DMRS type 1 or 2, if the terminal supports multi-user MIMO scheduling with an existing DMRS type 1 or 2, the terminal may report information regarding support for multi-user MIMO scheduling with said existing DMRS type 1 or 2 through terminal capabilities. Here, multi-user MIMO scheduling may be co-scheduling between an existing DMRS type 1 and an enhanced DMRS type 1, and / or co-scheduling between an existing DMRS type 2 and an enhanced DMRS type 2. Similarly to the above, the terminal may report the terminal capability regarding the possibility of co-scheduling between the existing type and the enhanced type as a common terminal capability, thereby reporting that only co-scheduling is possible between the existing type 1 and the enhanced type 1, or that only co-scheduling is possible between the existing type 2 and the enhanced type 2, and / or report that both type 1 and 2 are capable of co-scheduling between the existing type and the enhanced type, and / or report through individual terminal capabilities for each type.

[0395] In one embodiment, for a terminal that has reported terminal capability, the base station may set up enhanced DMRS type 1 and 2 methods to the terminal through upper layer signaling using the following methods.

[0396] - [Upper layer setting method 1] For example, the terminal can receive a setting from the base station that an enhanced DMRS type is supported within DMRS-DownlinkConfig, which is an upper layer signaling.

[0397] -- [Upper Layer Configuration Method 1-1] dmrs-Type-r18, an upper layer signaling similar to dmrs-Type, which determines the existing type, can be configured, and dmrs-Type-r18 can be used to define an enhanced DMRS type other than DMRS type 1 or 2. dmrs-Type, the upper layer signaling that determines the existing type, is a field for selecting the DMRS type used for DL ​​and can indicate that DMRS type 2 is used. If there is no field for selecting the DMRS type, the terminal can use DMRS type 1. Within the upper layer signaling DMRS-DownlinkConfig, an RRC IE named dmrs-Type-r18 can be newly configured for the terminal in addition to dmrs-Type. Additionally, through dmrs-Type-r18, one of DMRS type 1, 2, or enhanced DMRS type 1 or 2 may be determined. Additionally, either an enhanced DMRS type 1 or 2 may be determined. For example, if dmrs-Type-r18 is set as shown in [Table 20-1] below, one of DMRS type 2, enhanced DMRS type 1, or 2 may be determined. In this case, the existing dmrs-Type may be ignored. If dmrs-Type-r18 is not set, the DMRS type may be determined according to the setting method of dmrs-Type. Alternatively, in one embodiment, if dmrs-Type-r18 is set, one of 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, the DMRS type may be determined according to the setting method of dmrs-Type.When such a higher configuration method is used, the terminal may use only one of the existing method (e.g., DMRS type 1 or 2) and the enhanced method (e.g., enhanced DMRS type 1 or 2) of the DMRS type for each of PDSCH mapping type A or B. Such a higher configuration method may be a higher configuration method that does not allow dynamic switching between the existing method and the enhanced method, or does not consider dynamic switching itself. In this case, the RRC IE name dmrs-Type-r18 is merely an example, and the actual RRC IE name may differ from this. Of course, the RRC IE name is an example, and the RRC IE name of the present disclosure is not limited thereto.

[0398]

[0399] -- [Upper Layer Configuration Method 1-2] While retaining the existing meaning of dmrs-Type, which determines either DMRS type 1 or 2, a new RRC IE can be additionally configured to have the meaning of whether enhanced DMRS type 1 or 2 is available. For example, as shown in [Table 20-2] below, if the terminal does not receive a configuration for the upper layer signaling dmrs-Type from the base station and does not receive a configuration for enhanced-Dmrs-Type-r18, the terminal can support (use) the existing method for DMRS type 1. Additionally, if the terminal does not receive a configuration for dmrs-Type and receives enhanced-Dmrs-Type-r18 as enabled, the terminal can support (use) the enhanced method for DMRS type 1. If a terminal is configured for dmrs-Type (ENUMERATED {type2}) and has enhanced-Dmrs-Type-r18 set to enabled, the terminal can support (use) the enhanced method for DMRS type 2. In cases where the terminal supports dynamic switching between the existing type and the enhanced type, the terminal can perform dynamic switching without additional upper layer signaling based on the terminal being configured for enhanced-Dmrs-Type-r18. Alternatively, in this case, the terminal can be configured from the base station to enable dynamic switching via dynamicSwitchType, which is additional upper layer signaling. Definitions of RRC IE other than enhanced-Dmrs-Type-r18 in [Table 20-2] can be understood by referring to Table 20-1 above.

[0400]

[0401] - [Upper layer setting method 2] According to one embodiment, the terminal may not use DMRS-DownlinkConfig, which is an upper layer signaling, to support an enhanced DMRS type, but may instead receive a new RRC IE to set that an enhanced DMRS type is supported within PDSCH-Config individually. The RRC IE for supporting the enhanced DMRS type may be included within PDSCH-Config. For example, as shown in [Table 20-3] below, if the terminal does not receive enhanced-Dmrs-Type-r18, which is an upper layer signaling, from the base station, the terminal may determine the DMRS type according to the existing DMRS-DownlinkConfig setting. If the terminal receives enhanced-Dmrs-Type-r18, which is an upper layer signaling, from the base station, the terminal may use an enhanced method for the DMRS type determined according to the existing DMRS-DownlinkConfig setting. In the case where the terminal supports dynamic switching between the existing type and the enhanced type, if the terminal receives enhanced-Dmrs-Type-r18, the terminal can perform dynamic switching without additional upper layer signaling. Alternatively, in this case, the terminal can receive a setting from the base station regarding whether to perform dynamic switching through dynamicSwitchType, which is an additional upper layer signaling.

[0402]

[0403] [Enhanced DMRS Type 1 Support Method]

[0404] According to one embodiment of the present disclosure, a method for supporting enhanced DMRS type 1 can determine the time and frequency resource mapping of DMRS RE and the FD-OCC and TD-OCC coefficients therefor when using enhanced DMRS type 1 based on the following [Equation 3-1] and [Table 22-1-4]. The following details are based on the demodulation signal of the downlink data channel (PDSCH DMRS), which can be similarly applied to the demodulation signal of the uplink data channel (PUSCH DMRS), wherein the DMRS port number may be 0 to 15 rather than 1000 to 1015 as shown in the first column of [Table 17-1-1]. In the following [Equation 3-1] may mean the number of layers of PDSCH or PUSCH. Unless otherwise specifically stated, the parameters of Equation 3-1 can be understood by referring to the description of Equations 2 through 2-1 described above.

[0405] [Mathematical Formula 3-1]

[0406]

[0407]

[0408] According to one embodiment, the [enhanced DMRS type 1 support method] based on the above-described [Equation 3-1] and [Table 17-1-1] uses a total of two CDM groups, and for one front-loaded DMRS symbol, each CDM group may include four DMRS ports. Therefore, in this case, up to eight orthogonal DMRS ports can be supported. Additionally, for two front-loaded DMRS symbols, since each CDM group may include eight DMRS ports, a total of 16 orthogonal DMRS ports can be supported. Since the number of DMRS ports within a CDM group is increased while maintaining the number of CDM groups of the existing DMRS type 1 at two, and the OCC length for this is increased to four, the scheduling of PDSCH to be transmitted with the DMRS can be used in units of two RBs, and the DMRS can be mapped to the same RE position as the existing DMRS type 1.

[0409] However, the existing DMRS type 1 assumes that the channels of two REs (e.g., RE#0 and RE#2) located 2 RE apart are the same, and distinguishes orthogonal ports by applying OCC to the two REs, and in the case of one front-loaded DMRS symbol, since a total of 6 REs are used within one RB per port, three OCCs of length 2 can be used.

[0410] According to one embodiment, based on the [Enhanced DMRS type 1 Support Method], for a single front-loaded DMRS symbol, a total of 4 orthogonal antenna ports can be distinguished by using a length 4 OCC applied to 4 adjacent REs by using a total of 12 REs within 2 RBs per port. In this case, a length 4 OCC is applied to 4 REs, and each of the 4 REs may exist at a position separated by 2 REs from each other. That is, since the OCC must be applied by considering 4 REs with relative RE positions of 0, 2, 4, and 6 as the same channel, the channel estimation performance may decrease compared to the existing DMRS type 1. Therefore, the enhanced DMRS type 1 can be used for multi-user MIMO in channels with low frequency-selective characteristics. Referring to the aforementioned [Table 17-1-1], among the length 4 OCCs, ports 1000 to 1015 can have orthogonality between all ports. Values ​​may be determined. Of course, the values ​​in [Table 17-1-1] are exemplary and are of the present disclosure The value is not limited to this. In [Equation 3-1], is a scaling factor representing the ratio between PDSCH's EPRE (energy per RE) and DMRS's EPRE, and It can be calculated as follows. The value of can be 0 dB and -3 dB, respectively, depending on whether the number of CDM groups is 1 or 2.

[0411] [Enhanced DMRS Type 2 Support Method]

[0412] According to one embodiment, the time and frequency resource mapping of DMRS RE and the corresponding FD-OCC and TD-OCC coefficients can be determined by using an enhanced DMRS type 2 based on the following [Equation 3-2] and [Table 17-1-2]. The following [Equation 3-2] and [Table 17-1-2] can be understood as being based on the demodulation signal of the downlink data channel (PDSCH DMRS). This can be similarly applied to the demodulation signal of the uplink data channel (PUSCH DMRS). The DMRS port number can be determined to be 0 to 23, rather than 1000 to 1023, as shown in the first column of [Table 17-1-2]. In the following [Equation 3-2] may mean the number of layers of PDSCH or PUSCH. Unless otherwise specifically noted, the parameters of Equation 3-2 may correspond to the parameters described by referring to Equations 2 to 2-1 above.

[0413]

[0414]

[0415] According to one embodiment, in the [enhanced DMRS type 2 support method] based on [Equation 3-2] and [Table 17-1-2], a total of three CDM groups can be used. Additionally, for one front-loaded DMRS symbol, four DMRS ports can be included in each CDM group, so a total of 12 orthogonal DMRS ports can be supported, and for two front-loaded DMRS symbols, eight DMRS ports can be included in each CDM group, so a total of 24 orthogonal DMRS ports can be supported. By following this method, by increasing the number of DMRS ports within the CDM groups while maintaining the number of CDM groups, the scheduling of PDSCH to be transmitted with the DMRS can be maintained in units of one RB, just as before, and the DMRS can be mapped to the same RE position as the existing DMRS type 2.

[0416] In the case of the existing DMRS type 2, it is assumed that the channels of two consecutive REs are the same, and orthogonal ports are distinguished by applying OCC to the two REs. Since a total of four REs are used within one RB per port for one front-loaded DMRS symbol, two OCCs of length 2 can be used. On the other hand, in one embodiment of the present disclosure, according to the [enhanced DMRS type 2 support method], a total of four REs are used within one RB per port for one front-loaded DMRS symbol, and a total of four orthogonal ports can be distinguished by using one OCC of length 4. In this case, the OCC of length 4 is applied to two consecutive sets of REs separated by 6 REs; that is, since the OCC must be applied by considering four REs with relative RE positions of 0, 1, 6, and 7 as the same channel, the channel estimation performance may be lower than that of the existing DMRS type 2. Therefore, such an enhanced DMRS type 2 can be used for multi-user MIMO in channels with low frequency-selectivity characteristics. In [Equation 3-2] can mean a scaling factor representing the ratio between the EPRE (energy per RE) of PDSCH and the EPRE of DMRS. Is, It can be calculated as follows. In addition, depending on whether the number of CDM groups is 1, 2, or 3 The values ​​of can correspond to 0 dB, -3 dB, and -4.77 dB, respectively.

[0417] According to one embodiment, in the [enhanced DMRS type 1 support method] and [enhanced DMRS type 2 support method] described above, the terminal may report to the base station a terminal capability indicating that each support method is possible. The terminal capability may be valid only for FR1, or valid for both FR1 and FR2. The terminal capability may include information regarding the maximum number of ports that can be supported. For example, it may include information that, in enhanced DMRS type 1, a maximum of 8 ports can be supported when using 1 front-loaded DMRS symbol, and a maximum of 16 ports can be supported when using 2 front-loaded DMRS symbols. For example, it may include information indicating that, in enhanced DMRS type 2, a maximum of 12 ports can be supported when using 1 front-loaded DMRS symbol, and a maximum of 24 ports can be supported when using 2 front-loaded DMRS symbols. After receiving the terminal capability, the base station may set a corresponding upper layer signaling, which may be one of the upper layer signaling setting methods described above or an independent upper layer signaling.

[0418] According to one embodiment, the base station and the terminal may support at least one of the [enhanced DMRS type 1 support method] or the [enhanced DMRS type 2 support method]. For example, the base station and the terminal may support at least one of the [enhanced DMRS type 1 support method] or the [enhanced DMRS type 2 support method] by using a configuration method through upper layer signaling, an instruction method based on L1 signaling, or a combination method of upper layer signaling and L1 signaling, or a method fixedly specified in the standard.

[0419] <Second Embodiment: Enhanced DMRS type 1 and 2 additional support method supporting an increased number of orthogonal ports>

[0420] According to one embodiment of the present disclosure, enhanced DMRS types 1 and 2 supporting an increased number of orthogonal ports may be additionally supported. The present embodiment may operate in combination with other embodiments.

[0421] In one embodiment, as an additional parameter for the [Enhanced DMRS type 1 Support Method] described above, the relationship regarding which CDM group is included and which FD-OCC index and TD-OCC index can be used depending on which DMRS port is used can be additionally defined through [Table 17-2-1] below. Additionally, as an additional parameter for the [Enhanced DMRS type 2 Support Method] described above, the relationship regarding which CDM group is included and which FD-OCC index and TD-OCC index can be used depending on which DMRS port is used can be additionally defined through [Table 17-2-2] below. [Table 17-2-3] and [Table 17-2-4] below can define the FD-OCC indexes available in [Table 17-2-1] and [Table 17-2-2]. In addition, [Table 17-2-5] and [Table 17-2-6] below define the TD-OCC indices available in [Table 17-2-1] and [Table 17-2-2]. In [Table 17-2-1] and [Table 17-2-2] below, p can represent a DMRS port. Here, in the case of PDSCH, p is used to represent the DMRS port, and in the case of PUSCH, a value obtained by subtracting 1000 from p can be used to represent the DMRS port.

[0422] According to one embodiment, in the following [Table 17-2-1], DMRS ports 1000 to 1003 and 1008 to 1011 can be used for single or double front-loaded DMRS symbols, and DMRS ports 1004 to 1007 and 1012 to 1015 can be used for double front-loaded DMRS symbols.

[0423] According to one embodiment, in the following [Table 17-2-2], DMRS ports 1000 to 1005 and 1012 to 1017 can be used for single or double front-loaded DMRS symbols, and DMRS ports 1006 to 1011 and 1018 to 1023 can be used for double front-loaded DMRS symbols.

[0424] According to one embodiment, j used in the following [Tables 17-2-3] to [Tables 17-2-6] is an imaginary number, sqrt(-1)( It can mean ).

[0425] According to one embodiment, in order to support the [enhanced DMRS type 1 support method] and [enhanced DMRS type 2 support method] described above, the following [Table 17-2-1] and [Table 17-2-2] may each be used, and the indices of FD-OCC and TD-OCC to be used in each of [Table 17-2-1] and [Table 17-2-2] may be determined using at least one of the following [Table 17-2-3] to [Table 17-2-6], and said determination may be set to the terminal as upper layer signaling from the base station, dynamically instructed as L1 signaling, notified through a combination of upper layer signaling and L1 signaling, or defined in the standard.

[0426] According to one embodiment, the terminal may determine one of the FD-OCC and TD-OCCs in [Table 17-2-3] to [Table 17-2-6] below for scheduling of PDSCH and / or PUSCH from the base station. The terminal may apply the determined FD-OCC and TD-OCC to PDSCH and PUSCH scheduling in common.

[0427] According to one embodiment, the terminal may determine one of the FD-OCC and TD-OCC from [Table 17-2-3] to [Table 17-2-6] below for the scheduling of PDSCH and / or PUSCH from the base station and apply it to PDSCH scheduling. Additionally, the terminal may determine another FD-OCC and TD-OCC from [Table 17-2-3] to [Table 17-2-6] below and apply it to PUSCH scheduling. For example, the terminal may use the FD-OCC index and value of [Table 17-2-3] for the enhanced DMRS type 1 and 2 described above when scheduling PDSCH from the base station. Additionally, the terminal may use the FD-OCC index and value of [Table 17-2-4] for the enhanced DMRS type 1 and 2 described above when scheduling PUSCH from the base station. However, this is merely an example and the present disclosure is not limited thereto. For example, the same FD-OCC may be used for PDSCH and PUSCH, and different TD-OCCs may be used for PDSCH and PUSCH, respectively, and the present disclosure does not exclude any other combinations.

[0428] Tables 17-2-1 and 17-2-2 below are based on PDSCH DMRS and can be similarly applied to PUSCH DMRS. In this case, the DMRS port number may be determined as 1000 to 1015, as shown in the first column of Table 17-2-1, but is not limited thereto. For example, the DMRS port number may be determined as 0 to 15, rather than 1000 to 1005. For example, the DMRS port number may be determined as 0 to 23, rather than 1000 to 1023, as shown in the first column of Table 17-2-2.

[0429] The following [Table 17-2-6] is based on PUSCH DMRS and can be similarly applied to PDSCH DMRS. In this case, for enhanced DMRS type 1, the DMRS port number may be determined as 0–7, 8–15, as shown in the first row of [Table 17-2-6], but is not limited thereto. For example, the DMRS port number may be determined as 100–1007, 1008–1015, instead of 0–7, 8–15. For example, for enhanced DMRS type 2, the DMRS port number may be determined as 0–11, 12–23, as shown in the first row of [Table 17-2-6], but is not limited thereto. For example, the DMRS port number may be determined as 1000–1011, 1012–1023, instead of 0–11, 12–23.

[0430]

[0431]

[0432]

[0433]

[0434]

[0435]

[0436] Tables 21-1-1-1 to 21-1-1-8 below may include information that a terminal can use to be indicated to a PUSCH DMRS port when rank is 1 to 8, in the case where the terminal has been set to an enhanced DMRS type 1 through upper layer signaling from a base station for PUSCH DMRS (dmrs-Type=1, dmrs-TypeEnh setting), and maxLength, which is an upper layer signaling, is 1. In one embodiment, when the terminal is indicated to a PUSCH DMRS port through DCI format 0_1, 0_2, or 0_3 from a base station, according to the upper layer signaling setting described above (for example, when the terminal has been set to an enhanced DMRS type 1 from a base station and maxLength is set to 1), the terminal may consider the bit length of the antenna port field within DCI format 0_1, 0_2, or 0_3 to be 4 bits.

[0437]

[0438]

[0439]

[0440]

[0441]

[0442]

[0443]

[0444]

[0445] Tables [21-1-2-1] through [21-1-2-8] below may contain information that a terminal can use to be directed to a PUSCH DMRS port when rank is 1 to 8, in the case where the terminal has been directed to an enhanced DMRS type 1 through upper layer signaling from a base station for PUSCH DMRS (dmrs-Type=1, dmrs-TypeEnh setting), and the upper layer signaling maxLength is 2. If the terminal is directed to a PUSCH DMRS port through DCI format 0_1, 0_2, or 0_3 from a base station, according to the upper layer signaling setting described above (for example, when enhanced DMRS type 1 is set and maxLength is set to 2), the terminal may consider the bit length of the antenna port field within DCI format 0_1, 0_2, or 0_3 to be 5 bits.

[0446]

[0447]

[0448]

[0449]

[0450]

[0451]

[0452]

[0453]

[0454] Tables 21-2-1-1 to 21-2-1-8 below may include information that a terminal can use to be indicated to a PUSCH DMRS port when the terminal has been set to an enhanced DMRS type 2 via upper layer signaling from a base station for PUSCH DMRS (dmrs-Type=2, dmrs-TypeEnh setting), and when the upper layer signaling maxLength is 1 and the rank is 1 to 8. In one embodiment, when a terminal is indicated to a PUSCH DMRS port via DCI format 0_1, 0_2, or 0_3 from a base station, based on the upper layer signaling setting described above (e.g., when the terminal is set to an enhanced DMRS type 2 and maxLength is set to 1), the terminal may consider the bit length of the antenna port field within DCI format 0_1, 0_2, or 0_3 to be 5 bits.

[0455]

[0456]

[0457]

[0458]

[0459]

[0460]

[0461]

[0462]

[0463] Tables 21-2-2-1 to 21-2-2-8 below may include information that a terminal can use to be directed to a PUSCH DMRS port when rank is 1 to 8, in the case where the terminal has been directed to an enhanced DMRS type 2 via upper layer signaling from a base station for PUSCH DMRS (dmrs-Type=2, dmrs-TypeEnh setting), and the upper layer signaling maxLength is 2. In one embodiment, when the terminal is directed to a PUSCH DMRS port via DCI format 0_1, 0_2, or 0_3 from a base station, according to the upper layer signaling setting described above (for example, when enhanced DMRS type 2 is set and maxLength is set to 2), the terminal may consider the bit length of the antenna port field within DCI format 0_1, 0_2, or 0_3 to be 6 bits.

[0464]

[0465]

[0466]

[0467]

[0468]

[0469]

[0470]

[0471]

[0472] [Table 22-1-1] below may include information that the terminal can use to be directed to a PDSCH DMRS port when the terminal has been directed to an enhanced DMRS type 1 via upper layer signaling from a base station (dmrs-Type=1, dmrs-TypeEnh setting) and the upper layer signaling maxLength is 1. In one embodiment, when the terminal is directed to a PDSCH DMRS port via DCI format 1_1, 1_2, or 1_3 from a base station, according to the upper layer signaling setting described above (for example, when enhanced DMRS type 1 is set and maxLength is set to 1), the terminal may consider the bit length of the antenna port field within DCI format 1_1, 1_2, or 1_3 to be 5 bits.

[0473]

[0474] The following [Table 22-1-2] may include information that the terminal can use to be directed to a PDSCH DMRS port when the terminal has been set to Enhanced DMRS type 1 via upper layer signaling from the base station (dmrs-Type=1, dmrs-TypeEnh setting) and the upper layer signaling maxLength is 2. In one embodiment, when the terminal is directed to a PDSCH DMRS port via DCI format 1_1, 1_2, or 1_3 from the base station, according to the upper layer signaling setting described above (for example, when Enhanced DMRS type 1 is set and maxLength is set to 2), the terminal may consider the bit length of the antenna port field within DCI format 1_1, 1_2, or 1_3 to be 7 bits.

[0475]

[0476]

[0477] The following [Table 22-2-1] may include information that the terminal can use to be directed to a PDSCH DMRS port when the terminal has been directed to an enhanced DMRS type 2 via upper layer signaling from a base station (dmrs-Type=2, dmrs-TypeEnh setting) and the upper layer signaling maxLength is 1. In one embodiment, when the terminal is directed to a PDSCH DMRS port via DCI format 1_1, 1_2, or 1_3 from a base station, according to the upper layer signaling setting described above (for example, when enhanced DMRS type 2 is set and maxLength is set to 1), the terminal may consider the bit length of the antenna port field within DCI format 1_1, 1_2, or 1_3 to be 6 bits.

[0478]

[0479] The following [Table 22-2-2] may include information that the terminal can use to be directed to a PDSCH DMRS port when the terminal has been directed to an enhanced DMRS type 2 via upper layer signaling from a base station (dmrs-Type=2, dmrs-TypeEnh setting) and the upper layer signaling maxLength is 2. In one embodiment, when the terminal is directed to a PDSCH DMRS port via DCI format 1_1, 1_2, or 1_3 from a base station, according to the upper layer signaling setting described above (for example, when enhanced DMRS type 2 is set and maxLength is set to 2), the terminal may consider the bit length of the antenna port field within DCI format 1_1, 1_2, or 1_3 to be 8 bits.

[0480]

[0481]

[0482]

[0483] <Third Embodiment: MC-DCI Based Enhanced DMRS Support Method>

[0484] According to one embodiment of the present disclosure, a terminal and a base station may support an enhanced DMRS based on MC-DCI (e.g., DCI format 0_3 or / and 1_3). The present embodiment may operate in combination with other embodiments.

[0485] According to one embodiment, the terminal can receive PUSCH scheduling information for one or more cells from a base station via DCI format 0_3 as described above. Similarly, the terminal can receive PDSCH scheduling information for one or more cells from a base station via DCI format 1_3 as described above.

[0486] According to one embodiment, the terminal can receive information from the base station regarding a combination of one or more cells that can be scheduled through the scheduled cell set indicator field and the scheduled cells indicator field in DCI format 0_3 or / and 1_3.

[0487] According to one embodiment, the Scheduled cell set indicator field is It can be composed of bits. At this time can mean a logarithmic function with base 2. can represent the number of cell sets set via the upper layer signaling MC-DCI-SetofCellsToAddModList, and the maximum value can be 4.

[0488] According to one embodiment, if the scheduled cell set indicator field exists within DCI format 0_3 or / and 1_3, the terminal can interpret the scheduled cell set indicator field based on [Table 23] below. For example, if the terminal is indicated by 0 through the scheduled cell set indicator field, the terminal can identify the set of cells with the lowest index within MC-DCI-SetofCellsToAddModList set by upper layer signaling as being scheduled. For example, if the terminal is indicated by 1, 2, or 3 through the scheduled cell set indicator field, the terminal can identify the set of cells with the 2nd, 3rd, or 4th lowest index within MC-DCI-SetofCellsToAddModList set by upper layer signaling as being scheduled, respectively.

[0489] According to one embodiment, if the scheduled cell set indicator field does not exist within DCI format 0_3 or / and 1_3, the terminal can identify the scheduled cell set as a cell set configured within the upper layer signaling MC-DCI-SetofCellsToAddModList. Here, the meaning of the scheduled cell set indicator field not existing within DCI format 0_3 or / and 1_3 is that It could mean that the value of is 0. That is, The case where the value of is 0 Since this means that one is set, if the scheduled cell set indicator field does not exist in DCI format 0_3 or / and 1_3, it may mean that one cell set is set in MC-DCI-SetofCellsToAddModList.

[0490]

[0491] In the present disclosure, the Scheduled cells indicator field may mean a field indicating a combination of cells that the terminal can be scheduled to receive through DCI format 0_3 or / and 1_3.

[0492] According to one embodiment, in DCI format 1_3, if the terminal does not receive the upper layer signaling scheduledCellComboListDCI-1-3, the terminal can identify that the Scheduled cells indicator field is 0 bits. That is, in such a case, the terminal can consider that the Scheduled cells indicator field does not exist. If the terminal receives the upper layer signaling scheduledCellComboListDCI-1-3, the terminal [is] the Scheduled cells indicator field It can be considered as a bit. In this case, " " can mean a ceiling function, and " " can mean a logarithmic function with base 2, and " " can refer to the number of entries set within scheduledCellComboListDCI-1-3, which is the upper layer signaling.

[0493] According to one embodiment, when one entry is set within scheduledCellComboListDCI-1-3, the terminal can identify one or more cells that are instructed to schedule information through DCI format 1_3, even if the Scheduled cells indicator field does not exist.

[0494] According to one embodiment, the terminal can interpret the Scheduled cells indicator field in DCI format 1_3 based on the following [Table 24]. For example, if the terminal is indicated by 0 through the Scheduled cells indicator field in DCI format 1_3, the terminal can identify that it has received scheduling for one or more cells included in the first entry set in scheduledCellComboListDCI-1-3, which is an upper layer signaling. Similarly, if the terminal is indicated by 1 to 15 through the Scheduled cells indicator field in DCI format 1_3, the terminal can identify that it has received scheduling for one or more cells included in the 2nd to 16th entries set in scheduledCellComboListDCI-1-3, which is an upper layer signaling.

[0495]

[0496] According to one embodiment, in DCI format 0_3, if the terminal has not received the upper layer signaling scheduledCellComboListDCI-0-3, the terminal can identify that the Scheduled cells indicator field is 0 bits. That is, in such a case, the terminal can consider that the Scheduled cells indicator field does not exist. If the terminal has received the upper layer signaling scheduledCellComboListDCI-0-3, the terminal [is] the Scheduled cells indicator field It can be considered as a bit. In this case, can mean a ceiling function, and can mean a logarithmic function with base 2, and may refer to the number of entries set within scheduledCellComboListDCI-0-3, which is an upper layer signaling. If only one entry is set within scheduledCellComboListDCI-0-3, the terminal can identify one or more cells that have been instructed to schedule information through the DCI format 0_3, even though the Scheduled cells indicator field does not exist, as one or more cells that include the one entry set within scheduledCellComboListDCI-0-3, which is an upper layer signaling.

[0497] According to one embodiment, the terminal can interpret the Scheduled cells indicator field in DCI format 0_3 based on the following [Table 25]. For example, if the terminal is indicated by 0 through the Scheduled cells indicator field in DCI format 0_3, the terminal can identify that it is receiving scheduling for one or more cells included in the first entry set in scheduledCellComboListDCI-0-3, which is an upper layer signaling. For example, if the terminal is indicated by 1 to 15 through the Scheduled cells indicator field in DCI format 0_3, the terminal can identify that it is receiving scheduling for one or more cells included in the 2nd to 16th entries set in scheduledCellComboListDCI-0-3, which is an upper layer signaling.

[0498]

[0499] According to one embodiment, the terminal has a frequency domain resource assignment field within DCI format 1_3 total You can expect it to consist of several blocks.

[0500] According to one embodiment, when a terminal is configured to include more than one entry for the upper layer signaling scheduledCellComboListDCI-1-3, The value of can be determined by the number of scheduled cells indicated through the Scheduled cells indicator field in DCI format 1_3.

[0501] According to one embodiment, when a terminal is configured to include only one entry for the upper layer signaling scheduledCellComboListDCI-1-3, The value of can be determined by the number of cells set within scheduledCellComboListDCI-1-3.

[0502] According to one embodiment, when the terminal is not set for the upper layer signaling scheduledCellComboListDCI-1-3, The value of can be determined by the number of cells set within scheduledCellListDCI-1-3, which is the upper layer signaling.

[0503] According to one embodiment, the terminal can identify that each block in the frequency domain resource assignment field within DCI format 1_3 corresponds to a respective scheduled cell. The blocks may be arranged in ascending order of cell index such that the first block corresponds to the lowest cell index. Each block may be defined similarly to the frequency resource assignment field in DCI format 1_1 described above.

[0504] According to one embodiment, the terminal has a frequency domain resource assignment field within DCI format 0_3 total You can expect it to consist of several blocks.

[0505] According to one embodiment, when a terminal is configured to include more than one entry for the upper layer signaling scheduledCellComboListDCI-0-3, The value of can be determined by the number of scheduled cells indicated through the Scheduled cells indicator field in DCI format 0_3.

[0506] According to one embodiment, when a terminal is configured to include only one entry for the upper layer signaling scheduledCellComboListDCI-0-3, The value of can be determined by the number of cells set within scheduledCellComboListDCI-0-3.

[0507] According to one embodiment, if the terminal is not set for the upper layer signaling scheduledCellComboListDCI-0-3, The value of can be determined by the number of cells set within scheduledCellListDCI-0-3, which is the upper layer signaling.

[0508] According to one embodiment, the terminal may consider that each block in the frequency domain resource assignment field within DCI format 0_3 corresponds to each scheduled cell, and the blocks may be arranged in ascending order of cell index such that the first block corresponds to the lowest cell index. Each block may be defined similarly to the frequency resource assignment field within DCI format 0_1 ​​described above.

[0509] According to one embodiment, the terminal may receive antennaPortsDCI-1-3 or antennaPortsDCI1-3, which are upper layer signaling related to the antenna port field within DCI format 1_3, from the base station.

[0510] According to one embodiment, if a terminal is set to type1a for the upper layer signaling antennaPortsDCI-1-3 or antennaPortsDCI1-3, the terminal has an Antenna port field within DCI format 1_3 It can be identified as a bit. At this time, The value of can be determined by the number of cells set within scheduledCellListDCI-1-3, which is the upper layer signaling. It can be arranged in ascending order of cell index so that 1 corresponds to the lowest cell index. The value of may be 4, 5, or 6 bits, and the above-described [Table 16-1] to [Table 16-8] may be possible.

[0511] According to one embodiment, when a terminal is set to type 1a for antennaPortsDCI-1-3 or antennaPortsDCI1-3, which are upper layer signalings, the terminal can identify that all scheduled cells use the same DMRS table when interpreting the antenna port within DCI format 1_3. That is, when the terminal determines the antenna port field within DCI format 1_3 based on the type 1a setting, the terminal can expect that some of the upper layer signaling settings related to DMRS will be identical so that all scheduled cells interpret the same DMRS table when interpreting the antenna port field based on the scheduling information of each cell. For example, when a terminal is scheduled for a first cell, a second cell, and a third cell via DCI format 1_3, and the terminal is instructed to PDSCH mapping type A for the first cell and the second cell, and the terminal is instructed to PDSCH mapping type B for the third cell, the terminal can expect that the DMRS settings connected to the PDSCH mapping type A of the first cell and the second cell (e.g., dmrs-Type and maxLength) and the DMRS settings connected to the PDSCH mapping type B of the third cell (e.g., dmrs-Type and maxLength) are all set identically. For example, the terminal can receive dmrs-Type set to 1 and maxLength set to 1 as DMRS settings connected to the PDSCH mapping type A of the first cell and the second cell. In addition, the terminal can receive dmrs-Type set to 1 and maxLength set to 1 as DMRS settings connected to the PDSCH mapping type B of the third cell.As a result, the terminal can use [Table 16-1] when interpreting the antenna port field based on type 1a within DCI format 1_3 for the first cell, the second cell, and the third cell.

[0512] According to one embodiment, if a terminal is set to type 2 for the upper layer signaling antennaPortsDCI-1-3 or antennaPortsDCI1-3, the terminal has a total of Antenna port fields within DCI format 1_3. It can be expected to be composed of blocks. Each block may correspond to antenna port information of each scheduled cell, and the blocks may be arranged in ascending order of cell index such that the first block corresponds to the lowest cell index. The bit length of each block may be 4, 5, or 6 bits, and the above-described [Table 16-1] to [Table 16-8] may be possible.

[0513] According to one embodiment, the terminal may receive antennaPortsDCI-0-3 or antennaPortsDCI0-3, which are upper layer signalings related to the antenna port field within DCI format 0_3, from the base station.

[0514] According to one embodiment, if a terminal is set to type1a for the upper layer signaling antennaPortsDCI-0-3 or antennaPortsDCI0-3, the terminal has an Antenna port field within DCI format 0_3 It can be considered as a bit. In this case, The value of can be determined by the number of cells set within scheduledCellListDCI-0-3, which is the upper layer signaling. It can be arranged in ascending order of cell index so that 1 corresponds to the lowest cell index. The value of may be 2, 3, 4, or 5 bits, and the above-described [Table 16-9] to [Table 16-24] may be possible.

[0515] According to one embodiment, when a terminal receives a type1a setting for antennaPortsDCI-0-3 or antennaPortsDCI0-3, which is an upper layer signaling, the terminal may assume that all scheduled cells use the same DMRS table when interpreting the antenna port within DCI format 0_3. That is, when the terminal has an antenna port field within DCI format 0_3 based on the type1a setting, it can expect that some of the upper layer signaling settings related to DMRS will be identical so that all scheduled cells interpret the same DMRS table when interpreting the antenna port field based on the scheduling information of each cell. For example, if a terminal is scheduled for a first cell, a second cell, and a third cell via DCI format 0_3, and is instructed to PUSCH mapping type A for the first and second cells and PUSCH mapping type B for the third cell, the terminal can expect that the DMRS settings connected to PUSCH mapping type A of the first and second cells (e.g., dmrs-Type, maxLength, dmrs-UplinkTransformPrecoding, or / and tp-pi2BPSK) and the DMRS settings connected to PUSCH mapping type B of the third cell (e.g., dmrs-Type and maxLength) are all set identically. For example, the terminal can be set to 1 for dmrs-Type and to 1 for maxLength as DMRS settings connected to PUSCH mapping type A of the first and second cells. In addition, dmrs-Type can be set to 1 and maxLength can be set to 1 through the DMRS setting connected to PUSCH mapping type B of the third cell.Accordingly, when the terminal interprets the antenna port field based on type1a within DCI format 0_3 for the first cell, the second cell, and the third cell, it may interpret it based on one of [Table 16-9], [Table 16-10], [Table 16-11], or [Table 16-12], and one of these may be determined according to the rank value of PUSCH determined through the TPMI field within DCI format 0_3. According to one embodiment, the terminal may expect that antennaPortsDCI-0-3 or antennaPortsDCI0-3, which is an upper layer signaling capable of determining the type of the antenna port field within DCI format 0_3, and tpmi-DCI0-3-r18 or tpmi-DCI-0-3-r18, which is an upper layer signaling capable of determining the type of the TPMI field, are set to the same value. For example, a terminal can expect that antennaPortsDCI-0-3 or antennaPortsDCI0-3 and tpmi-DCI0-3-r18 or tpmi-DCI-0-3-r18 are both type 1a or set to type 2. For example, if the terminal is set to type 1a for antennaPortsDCI-0-3 or antennaPortsDCI0-3, the terminal can expect that the rank values ​​of the TPMI indicated by each block in the TPMI field within DCI format 0_3 are all the same, even if tpmi-DCI0-3-r18 or tpmi-DCI-0-3-r18 are set to type 2.

[0516] According to one embodiment, if a terminal is set to type2 for the upper layer signaling antennaPortsDCI-0-3 or antennaPortsDCI0-3, the terminal has a total of Antenna port fields within DCI format 0_3. It can be expected to be composed of blocks. Each block may correspond to antenna port information of each scheduled cell, and the blocks may be arranged in ascending order of cell index so as to correspond to the lowest cell index starting from the first block. The bit length of each block may be 2, 3, 4, or 5 bits, and the above-described [Table 16-9] to [Table 16-24] may be possible.

[0517] According to one embodiment, the terminal may report to the base station a terminal capability that includes information that it can simultaneously support the above-described enhanced DMRS type 1 or / and enhanced DMRS type 2 and DCI format 0_3 or / and 1_3. That is, when the terminal receives DCI format 0_3 or 1_3 from the base station, it may be instructed to receive enhanced DMRS type 1 or enhanced DMRS type 2 through the antenna port field within the DCI format 0_3 or 1_3.

[0518] According to one embodiment, the terminal can define terminal capabilities in various forms as shown in the following examples.

[0519] - For example, terminal capabilities can simultaneously support DCI format 1_3 and enhanced DMRS type 1.

[0520] - For example, terminal capabilities can simultaneously support DCI format 1_3 and enhanced DMRS type 2.

[0521] - For example, terminal capabilities can simultaneously support DCI format 0_3 and enhanced DMRS type 1.

[0522] - For example, terminal capabilities can simultaneously support DCI format 0_3 and enhanced DMRS type 2.

[0523] - For example, the terminal capability can simultaneously support DCI format 1_3 and enhanced DMRS type 1 or / and enhanced DMRS type 2. That is, through the terminal capability, the terminal can report that it is capable of simultaneous support between DCI format 1_3 and enhanced DMRS type 1, or simultaneous support between DCI format 1_3 and enhanced DMRS type 2. Alternatively, the terminal can select and report one of the following through the terminal capability: simultaneous support between DCI format 1_3 and enhanced DMRS type 1, simultaneous support between DCI format 1_3 and enhanced DMRS type 2, or simultaneous support between DCI format 1_3 and enhanced DMRS type 1 and DMRS type 2.

[0524] - For example, the terminal capability can simultaneously support DCI format 0_3 and enhanced DMRS type 1 or / and enhanced DMRS type 2. That is, through the terminal capability, the terminal can report that it is capable of simultaneous support between DCI format 0_3 and enhanced DMRS type 1, and simultaneous support between DCI format 0_3 and enhanced DMRS type 2. Alternatively, the terminal can select and report one of the following through the terminal capability: simultaneous support between DCI format 0_3 and enhanced DMRS type 1, simultaneous support between DCI format 0_3 and enhanced DMRS type 2, or simultaneous support between DCI format 0_3 and enhanced DMRS type 1 and DMRS type 2.

[0525] - For example, the terminal capability can simultaneously support DCI format 0_3 or / and DCI format 1_3 and enhanced DMRS type 1 or / and enhanced DMRS type 2. That is, through the terminal capability, the terminal can report that it is capable of simultaneous support between DCI format 1_3 and enhanced DMRS type 1, DCI format 1_3 and enhanced DMRS type 2, DCI format 0_3 and enhanced DMRS type 1, and DCI format 0_3 and enhanced DMRS type 2. Alternatively, the terminal may select and report one of the following through the terminal capability: simultaneous support for DCI format 1_3 and enhanced DMRS type 1, simultaneous support for DCI format 1_3 and enhanced DMRS type 2, or simultaneous support for DCI format 1_3 and enhanced DMRS type 1 and DMRS type 2; and may select and report one of the following: simultaneous support for DCI format 0_3 and enhanced DMRS type 1, simultaneous support for DCI format 0_3 and enhanced DMRS type 2, or simultaneous support for DCI format 0_3 and enhanced DMRS type 1 and DMRS type 2.

[0526] According to one embodiment, a terminal may receive dmrs-DownlinkForPDSCH-MappingTypeA or / and dmrs-DownlinkForPDSCH-MappingTypeB within the upper layer signaling PDSCH-config. dmrs-DownlinkForPDSCH-MappingTypeA or / and dmrs-DownlinkForPDSCH-MappingTypeB may be used in DCI format 1_1 and 1_3. Accordingly, if the terminal receives dmrs-TypeEnh-r18 enabled within the upper layer signaling dmrs-DownlinkForPDSCH-MappingTypeA or / and dmrs-DownlinkForPDSCH-MappingTypeB, the terminal may interpret the antenna port field as enhanced DMRS type 1 or enhanced DMRS type 2 when receiving DCI format 1_1. In addition, when the terminal receives DCI format 1_3, it may ignore the dmrs-TypeEnh-r18 value and interpret the antenna port field within DCI format 1_3 as DMRS type 1 or DMRS type 2.

[0527] According to one embodiment, the terminal may receive dmrs-DownlinkForPDSCH-MappingTypeA or / and dmrs-DownlinkForPDSCH-MappingTypeB within the upper layer signaling PDSCH-config. dmrs-DownlinkForPDSCH-MappingTypeA or / and dmrs-DownlinkForPDSCH-MappingTypeB may be used in DCI formats 1_1 and 1_3.

[0528] Therefore, if the terminal receives dmrs-TypeEnh-r18 set to enabled within the upper layer signaling dmrs-DownlinkForPDSCH-MappingTypeA or / and dmrs-DownlinkForPDSCH-MappingTypeB, the terminal can interpret the antenna port field as follows.

[0529] - For example, if the terminal does not report the above terminal capability (one of the above terminal capabilities, which means whether there is simultaneous support between the enhanced DMRS type and DCI format 0_3 / 1_3) to the base station, and the terminal receives DCI format 1_1 and 1_3, the terminal can interpret the antenna port field in DCI format 1_1 as enhanced DMRS type 1 or enhanced DMRS type 2, and the antenna port field in DCI format 1_3 as DMRS type 1 or DMRS type 2.

[0530] - For example, if a terminal reports the above terminal capability (one of the above terminal capabilities, which means whether there is simultaneous support between the enhanced DMRS type and DCI format 0_3 / 1_3) to a base station, and the terminal receives DCI format 1_1 and 1_3, the terminal can interpret the antenna port field within DCI format 1_1 and DCI format 1_3 as enhanced DMRS type 1 or enhanced DMRS type 2.

[0531] - For example, in a case where the terminal does not report to the base station a terminal capability (one of the above terminal capabilities, meaning whether there is simultaneous support between the enhanced DMRS type and DCI format 0_3 / 1_3) in a band or band combination or feature set that includes at least one serving cell that the terminal can be scheduled to DCI format 1_3, if the terminal receives antennaPortsDCI1-3-r18 or antennaPortsDCI-1-3-r18 as type 1A in MC-DCI-SetOfCells, which is an upper layer signaling in the serving cell receiving DCI format 1_3, and the terminal receives DCI format 1_1 and 1_3, the terminal may interpret the antenna port field in DCI format 1_1 as enhanced DMRS type 1 or enhanced DMRS type 2. The terminal may interpret the antenna port field in DCI format 1_3 as DMRS type 1 or DMRS type 2.

[0532] - For example, if a terminal receives antennaPortsDCI1-3-r18 or antennaPortsDCI-1-3-r18 as type 2 in MC-DCI-SetOfCells, which is an upper layer signaling, in a serving cell receiving DCI format 1_3, and the terminal has not reported the terminal capability (one of the terminal capabilities, meaning whether there is simultaneous support between the enhanced DMRS type and DCI format 0_3 / 1_3) for some of the one or more cells scheduled for DCI format 1_3, and has reported the terminal capability for the remaining parts, if the terminal receives DCI format 1_1 and 1_3, the terminal may interpret the antenna port field in DCI format 1_1 as enhanced DMRS type 1 or enhanced DMRS type 2. The terminal may interpret the antenna port field in DCI format 1_3 as DMRS type 1 or DMRS type 2 for the antenna port field corresponding to the cell where the terminal capability was not reported. The terminal can interpret the antenna port field corresponding to the cell where the terminal capability is reported as enhanced DMRS type 1 or enhanced DMRS type 2.

[0533] - If a terminal receives antennaPortsDCI1-3-r18 or antennaPortsDCI-1-3-r18 as type 1A in MC-DCI-SetOfCells, which is an upper layer signaling in a serving cell receiving DCI format 1_3, and the terminal does not report the terminal capability (one of the terminal capabilities meaning whether there is simultaneous support between the enhanced DMRS type and DCI format 0_3 / 1_3) for some of the one or more cells scheduled for DCI format 1_3, and reports the terminal capability for the remaining parts, and if the terminal receives DCI format 1_1 and 1_3, the terminal may interpret the antenna port field in DCI format 1_1 as enhanced DMRS type 1 or enhanced DMRS type 2. The terminal may interpret the antenna port field in DCI format 1_3 as DMRS type 1 or DMRS type 2 for the antenna port field corresponding to the cell where the terminal capability was not reported. The terminal can interpret the antenna port field corresponding to the cell where the terminal capability is reported as enhanced DMRS type 1 or enhanced DMRS type 2.

[0534] According to one embodiment, through DCI format 1_3, if the terminal receives the upper layer signaling antennaPortsDCI1-3-r18 or antennaPortsDCI-1-3-r18 as type 1A as described above, it can be expected that there is one antenna port field within DCI format 1_3, and it can be expected that the same DMRS table is used when interpreting and applying the corresponding antenna port field to all scheduled cells. Consequently, even if the terminal can receive scheduling based on enhanced DMRS through DCI format 1_3, if all scheduled cells must interpret the antenna port field based on the same DMRS table according to the constraints of type 1a described above, all scheduled cells will inevitably be scheduled as the same type, either the DMRS type or the enhanced DMRS type, and this may become a limitation when attempting to perform flexible scheduling through a single DCI, which was the purpose of introducing DCI format 1_3. In particular, while the antenna port in DCI format 1_3 has the advantage of reducing the overhead of antenna port indication when set to type 1a, as mentioned above, it may result in constraints in scheduling where the enhanced DMRS type must be used for all scheduled cells or the DMRS type must be used for all scheduled cells. This problem may also appear in the antenna port field in DCI format 0_3.

[0535] Various embodiments of the present disclosure may provide a method in which the antenna port field can operate as type 1a, while the terminal and the base station each receive a DMRS type or an enhanced DMRS type for one or more cells scheduled via DCI format 0_3 or / and 1_3. To this end, the terminal and the base station according to various embodiments of the present disclosure may support at least one of the following methods or a combination of two or more.

[0536] [Method 1]

[0537] According to one embodiment, if the terminal is set to type 1a, antennaPortsDCI0-3-r18 or antennaPortsDCI-0-3-r18 in DCI format 0_3, or antennaPortsDCI1-3-r18 or antennaPortsDCI-1-3-r18 in DCI format 1_3, the terminal can expect to be instructed with a DMRS type (dmrs-TypeEnh not set) or an enhanced DMRS type (dmrs-TypeEnh set) for all cells scheduled through DCI format 0_3 or / and 1_3. Thus, although the terminal can be instructed with an enhanced DMRS type through DCI format 0_3 or / and 1_3, the terminal can be instructed with a DMRS type for all scheduled cells or an enhanced DMRS type for all scheduled cells. In other words, the terminal may not expect to be instructed to use an enhanced DMRS type for a specific cell among the scheduled cells and a DMRS type for the remaining cells. In such cases, the scheduling freedom of the terminal and the base station may be restricted. Additionally, as described above, since DCI format 1_3 shares DMRS settings with DCI format 1_1 and DCI format 0_3 shares DMRS settings with DCI format 0_1, if a DMRS type is applied to all cells scheduled via DCI format 0_3 and / or 1_3, a situation may arise where the terminal must be restricted to the DMRS type for the DMRS settings of DCI format 0_1 ​​and / or 1_1 as well, even though it may be able to support an enhanced DMRS type.

[0538] [Method 2]

[0539] According to one embodiment, a terminal can expect to be instructed with a DMRS type for all cells scheduled through DCI format 0_3 and / or 1_3 (dmrs-TypeEnh not set) or an enhanced DMRS type (dmrs-TypeEnh set), provided that the terminal is set to type 1a for antennaPortsDCI0-3-r18 or antennaPortsDCI-0-3-r18 in DCI format 0_3 or / or antennaPortsDCI-1-3-r18 in DCI format 1_3. Thus, although the terminal can be instructed with an enhanced DMRS type through DCI format 0_3 or / or 1_3, it can be instructed with a DMRS type for all cells scheduled through DCI format 0_3 or / or 1_3. In other words, the terminal may not expect to be instructed to receive an enhanced DMRS type for a specific cell among the scheduled cells and a DMRS type for the remaining cells. In such cases, the scheduling freedom of the terminal and the base station may be restricted.

[0540] Additionally, as described above, if the antenna port of DCI format 0_3 or / and 1_3 is defined based on type 1a, the terminal can expect that at least dmrs-Type and maxLength among the upper layer signaling related to DMRS scheduling information for each cell being scheduled will both have the same value.

[0541] In the case of [Method 2], unlike the above-described [Method 1], the terminal can remove the constraint on the degree of freedom of upper-layer signaling settings caused by sharing DMRS settings by defining and receiving individual DMRS setting parameters for DCI format 0_1 ​​and 1_3 and DCI format 0_1 ​​and 1_1 from the base station. That is, even though the terminal can expect to be instructed to a DMRS type or an enhanced DMRS type for all scheduled cells for DCI format 0_3 or / and 1_3, by setting individual upper-layer signaling for DCI format 0_1 ​​and 1_1, it can support the case where an enhanced DMRS type is used for DCI format 0_1 ​​and 1_1 and a DMRS type is used for DCI format 0_3 or / and 1_3.

[0542] [Method 3]

[0543] According to one embodiment, if the terminal receives antennaPortsDCI0-3-r18 or antennaPortsDCI-0-3-r18 in DCI format 0_3, or antennaPortsDCI1-3-r18 or antennaPortsDCI-1-3-r18 in DCI format 1_3 as type1a, the terminal may be instructed to a DMRS type or an enhanced DMRS type for each scheduling cell. That is, even if the antenna port field in DCI format 0_3 or / and 1_3 is defined based on type1a, the terminal may not be restricted on whether to receive an enhanced DMRS type or a DMRS type for each cell. However, regardless of whether the terminal is set to a DMRS type or an enhanced DMRS type, when interpreting the antenna port in DCI format 0_3 or / and 1_3, the terminal may interpret the antenna port based on the DMRS type (dmrs-TypeEnh is not set). That is, when the terminal resolves the antenna port in DCI format 0_3 or / and 1_3, it may apply the constraint of using the same DMRS table, but may not impose a constraint on whether dmrs-TypeEnh is set for each cell. As a result, the terminal may freely set the DMRS type of DCI format 0_1 ​​and 1_1.For example, assuming a case where a terminal is scheduled for a first cell and a second cell through DCI format 1_3, if the PDSCH mapping type indicated to the terminal through the first cell-related scheduling information is PDSCH mapping type A, and the DMRS settings connected thereto are dmrs-Type 1, maxLength 1, and dmrs-TypeEnh set, and the PDSCH mapping type indicated through the second cell-related scheduling information is PDSCH mapping type A, and the DMRS settings connected thereto are dmrs-Type 1 and maxLength 1, and dmrs-TypeEnh is not set, the terminal can interpret the Antenna port by assuming the case where dmrs-TypeEnh is not set when interpreting the Antenna port field defined as type1a in DCI format 1_3 to obtain DMRS port-related information to be indicated to both the first cell and the second cell. That is, the terminal can interpret the antenna port using a DMRS type other than an enhanced DMRS type. In addition, when the terminal receives PDSCH scheduling through DCI format 1_1 in the first cell, the terminal can interpret the antenna port as an enhanced DMRS type by assuming that the antenna port field in DCI format 1_1 is set to dmrs-TypeEnh.

[0544] According to one embodiment, additionally, when the antenna port of DCI format 0_3 or / and 1_3 is defined based on type 1a as described above, the terminal can expect that at least dmrs-Type and maxLength among the upper layer signaling related to DMRS scheduling information for each cell being scheduled have the same value.

[0545] [Method 4]

[0546] It can be observed that there is some overlap in the DMRS tables for DMRS type (dmrs-TypeEnh not set) and enhanced DMRS type (dmrs-TypeEnh set), which can be specifically verified through the following examples.

[0547] - For example, the above-described [Table 16-1] and [Table 22-1-1] both apply to cases where dmrs-Type is set to 1 and maxLength is set to 1 for PDSCH DMRS, and the only difference may be whether dmrs-TypeEnh is set ([Table 16-1] is used when dmrs-TypeEnh is not set, and [Table 22-1-1] is used when dmrs-TypeEnh is set). If the terminal is scheduled for 1 TB, it can be confirmed that entries 0 to 11 of [Table 22-1-1] have the same information as entries 0 to 11 of [Table 16-1].

[0548] - For example, the above-described [Table 16-3] and [Table 22-1-2] both represent cases where dmrs-Type is set to 1 and maxLength is set to 2 for PDSCH DMRS, and the only difference may be whether dmrs-TypeEnh is set ([Table 16-3] is used when dmrs-TypeEnh is not set, and [Table 22-1-2] is used when dmrs-TypeEnh is set). If the terminal is scheduled for 1 TB, it can be confirmed that entries 0 to 11 of [Table 22-1-2] have the same information as entries 0 to 11 of [Table 16-3], and entries 27 to 45 of [Table 22-1-2] have the same information as entries 12 to 30 of [Table 16-3].

[0549] According to one embodiment, the DMRS port supported by the enhanced DMRS type may include the DMRS port supported by the DMRS type. This can be confirmed through [Table 26] below.

[0550]

[0551] Referring to [Table 26] above, for DMRS type 1 (dmrs-TypeEnh not set, dmrs-Type = 1), when maxLength is set to 1, the range of DMRS ports can be 1000, 1001, 1002, and 1003. For enhanced DMRS type 1 (dmrs-TypeEnh set, dmrs-Type=1), when maxLength is set to 1, the range of DMRS ports can be 1000, 1001, 1002, and 1003, in addition to 1008, 1009, 1010, and 1011. That is, the range of DMRS ports for enhanced DMRS type 1 (dmrs-TypeEnh set, dmrs-Type=1) may include the range of DMRS ports for DMRS type 1 (dmrs-TypeEnh not set, dmrs-Type = 1). It can be understood that DMRS type 2 and enhanced DMRS type 2 may similarly have 1000, 1001, 1002, 1003, 1004, and 1005 as a common DMRS port range, corresponding to the case of DMRS type 1.

[0552] Accordingly, in one embodiment, when the terminal is configured with an enhanced DMRS type, it may be instructed to a range of DMRS ports that can be used only in the enhanced DMRS type in addition to the range of DMRS ports that can be used in the DMRS type. In other words, when the terminal is configured with an enhanced DMRS type, it may be possible to operate even if it is instructed only to a range of DMRS ports that can be used in the DMRS type, although this may be a restrictive DMRS port instruction. Accordingly, when the terminal is configured with antennaPortsDCI0-3-r18 or antennaPortsDCI-0-3-r18 in DCI format 0_3, or antennaPortsDCI1-3-r18 or antennaPortsDCI-1-3-r18 in DCI format 1_3 as type1a, the terminal may be instructed to a DMRS type or an enhanced DMRS type for each scheduling cell. In this case, the terminal can interpret the Antenna port field defined as type1a based on the DMRS table corresponding to the DMRS type (dmrs-TypeEnh not set) for cells among the scheduled cells that have the enhanced DMRS type set, without any constraint on whether the enhanced DMRS type or the DMRS type is set for each cell. In this case, the terminal can consider the FD-OCC length to be 4. That is, the terminal interprets information regarding the DMRS port index based on the DMRS table corresponding to the DMRS type (dmrs-TypeEnh not set), but the FD-OCC corresponding to the DMRS port can be considered as the FD-OCC of length 4 used in the enhanced DMRS type (dmrs-TypeEnh set), rather than the FD-OCC of length 2 used in the DMRS type (dmrs-TypeEnh not set).

[0553] The FD-OCC of length 2 used in the above-described DMRS type (dmrs-TypeEnh not set) can be understood in accordance with [Table 17-1] and [Table 17-2] above for PDSCH DMRS, and likewise in accordance with [Table 17-1a] and [Table 17-2a] above for PUSCH DMRS.

[0554] The FD-OCC of length 4 used in the above-described enhanced DMRS type (dmrs-TypeEnh set) can be understood according to [Table 17-1-1], [Table 17-1-2], and [Table 17-2-3] for PDSCH DMRS, and according to [Table 17-2-4] for PUSCH DMRS.

[0555] For example, in the case of entry 0 of [Table 16-1] above, it may include the meaning to receive PDSCH by applying DMRS port 1000 when DMRS type 1 (dmrs-Type=1, dmrs-TypeEnh not set). When entry 0 is interpreted as DMRS type (dmrs-TypeEnh not set), the FD-OCC may have a length of 2 and correspond to [+1, +1]. That is, the terminal may refer to the FD-OCC of length 2 in [Table 17-1-1] above, or may use only the first two values ​​among the FD-OCC of length 4 in [Table 17-1-1] above. For example, the terminal may use the part corresponding to k'=0, k'=1 in [Table 17-1-1] and not use the part corresponding to k'=2, k'=3. If the terminal interprets the entry as an enhanced DMRS type (dmrs-TypeEnh is set), the FD-OCC has a length of 4 and can correspond to [+1, +1, +1, +1]. That is, the terminal can refer to the FD-OCC of length 4 in [Table 17-1-1] above. For example, the terminal can use the part corresponding to k'=0, k'=1, k'=2, k'=3 in [Table 17-1-1].

[0556] For example, in the case of Entry 1 of [Table 16-1], it may include the meaning to receive PDSCH by applying DMRS port 1001 when DMRS type 1 (dmrs-Type=1, dmrs-TypeEnh not set). When Entry 1 is interpreted as DMRS type (dmrs-TypeEnh not set), the FD-OCC has a length of 2 and can correspond to [+1, -1]. That is, the terminal can refer to the FD-OCC of length 2 in [Table 17-1-1] above, or use only the first two values ​​among the FD-OCC of length 4 in [Table 17-1-1] above. For example, the terminal may use the part corresponding to k'=0, k'=1 in [Table 17-1-1] and not use the part corresponding to k'=2, k'=3. When entry 1 is interpreted as an enhanced DMRS type (dmrs-TypeEnh set), the FD-OCC has a length of 4 and can correspond to [+1, -1, +1, -1]. For example, the terminal can use the parts corresponding to k'=0, k'=1, k'=2, k'=3 in [Table 17-1-1].

[0557] According to one embodiment, as described above, the DMRS ports that are common to the enhanced DMRS type (dmrs-TypeEnh set) and the DMRS type (dmrs-TypeEnh not set) may have different FD-OCC lengths of 2 or 4, but the FD-OCC length of 4 may be in the form of repeating the FD-OCC length of 2 twice.

[0558] According to one embodiment, the terminal can obtain a greater spatial multiplexing effect while maintaining the constraint of using the same DMRS table when interpreting antenna ports in DCI format 0_3 or / and 1_3. For example, since the terminal applies the FD-OCC length differently depending on the enhanced DMRS type (dmrs-TypeEnh set) or DMRS type (dmrs-TypeEnh not set), depending on the scheduling situation for each cell, when instructed via the enhanced DMRS type, a longer FD-OCC length can be used during MU-MIMO scheduling with other terminals to utilize more orthogonal ports, thereby obtaining a greater spatial multiplexing effect.

[0559] Additionally, according to one embodiment of the present disclosure, without constraints on setting the DMRS type (dmrs-TypeEnh not set) or the enhanced DMRS type (dmrs-TypeEnh set) for each cell, some indication for the enhanced DMRS type (dmrs-TypeEnh set) may be possible using a DMRS table based on the DMRS type (dmrs-TypeEnh not set). In this case, one or two bits may be saved as the bit length of the Antenna port field in DCI format 0_3 or / and 1_3 is also defined based on the DMRS type (dmrs-TypeEnh not set).

[0560] In addition, according to one embodiment of the present disclosure, there may be no restrictions on whether dmrs-TypeEnh is set for each cell. As a result, the DMRS type of DCI format 0_1 ​​and 1_1 can be freely set. For example, in the case where a terminal is scheduled for a first cell and a second cell through DCI format 1_3, if the PDSCH mapping type indicated to the terminal through the first cell-related scheduling information is PDSCH mapping type A and the DMRS settings connected thereto have dmrs-Type 1, maxLength 1, and dmrs-TypeEnh set, and the PDSCH mapping type indicated through the second cell-related scheduling information is PDSCH mapping type A and the DMRS settings connected thereto have dmrs-Type 1 and maxLength 1, and dmrs-TypeEnh is not set, the terminal may interpret the Antenna port field defined as type1a in DCI format 1_3 in order to obtain DMRS port-related information to be indicated to both the first cell and the second cell by assuming the case where dmrs-TypeEnh is not set. For example, the terminal can interpret the Antenna port field as a DMRS type other than an enhanced DMRS type. Additionally, when the terminal receives PDSCH scheduling through DCI format 1_1 in the first cell, the terminal can interpret the Antenna port field in DCI format 1_1 as an enhanced DMRS type by assuming that dmrs-TypeEnh is set.

[0561] According to one embodiment, if the antenna port of DCI format 0_3 or / and 1_3 is defined based on type 1a as described above, the terminal can expect that at least dmrs-Type and maxLength among the upper layer signaling related to DMRS scheduling information for each cell being scheduled have the same value.

[0562] [Method 5]

[0563] According to one embodiment, if the terminal receives antennaPortsDCI0-3-r18 or antennaPortsDCI-0-3-r18 in DCI format 0_3, or antennaPortsDCI1-3-r18 or antennaPortsDCI-1-3-r18 in DCI format 1_3 as type 1a, the terminal may be instructed to a DMRS type or an enhanced DMRS type for each scheduling cell. That is, even if the antenna port field in DCI format 0_3 or / and 1_3 is defined based on type 1a, the terminal may not be restricted on whether to receive an enhanced DMRS type or a DMRS type for each cell. For example, the terminal may receive scheduling for a first cell, a second cell, and a third cell through DCI format 0_3 or / and 1_3. Additionally, one antenna port field defined based on type 1a may be included in DCI format 0_3 or / and 1_3. Additionally, the bit length of the antenna port may be determined according to the bit length of the enhanced DMRS type (dmrs-TypeEnh set) if at least one of the scheduled first to third cells is set and indicated for the enhanced DMRS type (dmrs-TypeEnh set). On the other hand, if all scheduled cells are of the DMRS type (dmrs-TypeEnh not set), the bit length of the antenna port may be determined according to the bit length of the DMRS type (dmrs-TypeEnh not set).

[0564] According to one embodiment, in the case of PDSCH DMRS, when the terminal receives the upper layer signaling dmrs-Type set to 1 and maxLength set to 1, 4 bits may be required for the Antenna port field in the case of DMRS type (dmrs-TypeEnh not set), and 5 bits may be required for the Antenna port field in the case of enhanced DMRS type (dmrs-TypeEnh set). Accordingly, as in the example described above, when at least one enhanced DMRS type (dmrs-TypeEnh set) among the first to third cells is set and indicated, the terminal may assume that the Antenna port field in DCI format 1_3 has a length of 5 bits. When the terminal interprets the 5-bit Antenna port field, if it interprets scheduling information for the first cell through DCI format 1_3, it may interpret the instruction for the DMRS port using all 5 bits. When a terminal interprets scheduling information for the second cell and the third cell, the terminal can interpret instructions for the DMRS port using the 4 bits of the LSB (Least Significant Bit). At this time, since the DMRS port information instructions for the first cell and the DMRS port information instructions for the second and third cells are all indicated through a single common Antenna port field, the terminal can expect the 4 bits of the LSB to be indicated with the same value. Accordingly, there may be a restriction on instructions for the enhanced DMRS type (dmrs-TypeEnh is set).

[0565] According to one embodiment, in the case of PDSCH DMRS, where the terminal receives the upper layer signaling dmrs-Type set to 1 and maxLength set to 2, 5 bits may be required for the Antenna port field in the case of DMRS type (dmrs-TypeEnh not set), and 7 bits may be required for the Antenna port field in the case of enhanced DMRS type (dmrs-TypeEnh set). Accordingly, as in the example described above, if at least one enhanced DMRS type (dmrs-TypeEnh set) among the first to third cells is set and indicated, the terminal may assume that the Antenna port field in DCI format 1_3 has a length of 7 bits. When the terminal interprets the 7-bit Antenna port field, the terminal may interpret the instruction for the DMRS port by using all 7 bits when interpreting scheduling information for the first cell through DCI format 1_3. When the terminal interprets scheduling information for the second cell and the third cell, the terminal can interpret instructions for the DMRS port using 5 bits of the LSB (Least Significant Bit). At this time, since the DMRS port information instruction for the first cell and the DMRS port information instruction for the second and third cells are all indicated through a single common Antenna port field, the terminal can expect the 5 bits of the LSB to be indicated with the same value. Accordingly, there may be a restriction on instructions for the enhanced DMRS type (dmrs-TypeEnh is set).

[0566] According to one embodiment, in the case of PDSCH DMRS, if the terminal receives the upper layer signaling dmrs-Type set to 2 and maxLength set to 1, 5 bits may be required for the Antenna port field in the case of DMRS type (dmrs-TypeEnh not set), and 6 bits may be required for the Antenna port field in the case of enhanced DMRS type (dmrs-TypeEnh set). Accordingly, as in the example described above, if at least one enhanced DMRS type (dmrs-TypeEnh set) among the first to third cells is set and indicated, the terminal may assume that the Antenna port field in DCI format 1_3 has a length of 6 bits. When the terminal interprets the 6-bit Antenna port field, the terminal may interpret the instruction for the DMRS port by using all 6 bits when interpreting scheduling information for the first cell through DCI format 1_3. When the terminal interprets scheduling information for the second cell and the third cell, the terminal can interpret instructions for the DMRS port using 5 bits of the LSB (Least Significant Bit). At this time, since the DMRS port information instruction for the first cell and the DMRS port information instruction for the second and third cells are all indicated through a single common Antenna port field, the terminal can expect the 5 bits of the LSB to be indicated with the same value. Accordingly, there may be a restriction on instructions for the enhanced DMRS type (dmrs-TypeEnh is set).

[0567] According to one embodiment, in the case of PDSCH DMRS, when the terminal receives the upper layer signaling dmrs-Type set to 1 and maxLength set to 2, 6 bits may be required for the Antenna port field in the case of DMRS type (dmrs-TypeEnh not set), and 8 bits may be required for the Antenna port field in the case of enhanced DMRS type (dmrs-TypeEnh set). Accordingly, as in the example described above, if at least one enhanced DMRS type (dmrs-TypeEnh set) among the first to third cells is set and indicated, the terminal may assume that the Antenna port field in DCI format 1_3 has a length of 8 bits. When the terminal interprets the 5-bit Antenna port field, the terminal may interpret the instruction for the DMRS port by using all 8 bits when interpreting scheduling information for the first cell through DCI format 1_3. When the terminal interprets scheduling information for the second cell and the third cell, the terminal can interpret instructions for the DMRS port using the 6 bits of the LSB (Least Significant Bit). At this time, since the DMRS port information instruction for the first cell and the DMRS port information instruction for the second and third cells are all indicated through a single common Antenna port field, the terminal can expect the 6 bits of the LSB to be indicated with the same value. Accordingly, there may be a restriction on instructions for the enhanced DMRS type (dmrs-TypeEnh is set).

[0568] According to one embodiment, additionally, when the antenna port of DCI format 0_3 or / and 1_3 is defined based on type 1a as described above, the terminal can expect that at least dmrs-Type and maxLength among the upper layer signaling related to DMRS scheduling information for each cell being scheduled have the same value.

[0569] According to one embodiment of the present disclosure, the scheduling freedom of a base station can be improved depending on the upper layer signaling setting status for each cell. Through the above-described [Method 5], since the terminal does not impose restrictions on whether dmrs-TypeEnh is set for each cell, it can be instructed via DMRS type (dmrs-TypeEnh not set) or enhanced DMRS type (dmrs-TypeEnh set) for each cell for one or more cells scheduled via DCI format 0_3 or / and 1_3, so the scheduling freedom of the base station can be additionally secured compared to the above [Methods 1] to [4] depending on the upper layer signaling setting status for each cell. However, as described above, some LSB bits of the Antenna port field defined based on type1a apply the same value to all cells indicated based on the DMRS type (dmrs-TypeEnh not set) or the enhanced DMRS type (dmrs-TypeEnh set); that is, for the enhanced DMRS type (dmrs-TypeEnh set), DMRS port indication is possible only for some of the entries in the entire DMRS table. Therefore, scheduling constraints may occur for cells that receive DMRS port scheduling information based on the enhanced DMRS type (dmrs-TypeEnh set).

[0570] According to one embodiment of the present disclosure, the DMRS type of DCI format 0_1 ​​and 1_1 can be set relatively freely. That is, since the terminal may not impose restrictions on whether to set dmrs-TypeEnh for each cell, the DMRS type of DCI format 0_1 ​​and 1_1 can be set freely. For example, in the case where a terminal is scheduled for a first cell and a second cell via DCI format 1_3, the terminal may interpret the Antenna port field defined as type1a in DCI format 1_3 by assuming that dmrs-TypeEnh is not set when interpreting the Antenna port field, which is defined as type1a in DCI format 1_3 to obtain DMRS port-related information to be directed to both the first cell and the second cell, if the PDSCH mapping type indicated by the terminal via the first cell-related scheduling information is PDSCH mapping type A and the DMRS settings connected thereto are dmrs-Type 1 and maxLength 1 and dmrs-TypeEnh is not set, and if the PDSCH mapping type indicated by the terminal via the second cell-related scheduling information is PDSCH mapping type A and the DMRS settings connected thereto are dmrs-Type 1 and maxLength 1 and dmrs-TypeEnh is not set. That is, the terminal may interpret the Antenna port field as a DMRS type other than an enhanced DMRS type. In addition, when the terminal receives PDSCH scheduling through DCI format 1_1 in the first cell, the terminal can interpret the Antenna port field in DCI format 1_1 as an enhanced DMRS type by assuming that dmrs-TypeEnh is set in the Antenna port field.

[0571] [Method 6]

[0572] According to one embodiment, if the terminal is configured to have antennaPortsDCI0-3-r18 or antennaPortsDCI-0-3-r18 in DCI format 0_3, or antennaPortsDCI1-3-r18 or antennaPortsDCI-1-3-r18 in DCI format 1_3 as type 1a, the terminal may be instructed to have a DMRS type or an enhanced DMRS type for each scheduling cell. That is, even if the antenna port field in DCI format 0_3 or / and 1_3 is defined based on type 1a, there may be no restriction on whether to have an enhanced DMRS type or a DMRS type configured for each cell. Additionally, if at least one of the scheduled cells has different settings for the upper layer signaling dmrs-TypeEnh (e.g., one cell is DMRS type-based (dmrs-TypeEnh not set), and the other cell is enhanced DMRS type-based (dmrs-TypeEnh set)), the terminal may expect two type1a-based antenna port fields to exist within DCI format 0_3 or / and 1_3. In this case, one of the two type1a-based antenna port fields may be applied to the cells scheduled based on the DMRS type (dmrs-TypeEnh not set), and the other may be applied to the cells scheduled based on the enhanced DMRS type (dmrs-TypeEnh set). In addition, the terminal can expect that if the DMRS port scheduling information of all scheduled cells is indicated as DMRS type (dmrs-TypeEnh not set) or enhanced DMRS type (dmrs-TypeEnh set), there is one antenna port field defined based on type1a in DCI format 0_3 or / and 1_3.The terminal can receive DMRS port-related scheduling information for all scheduled cells through the corresponding antenna port field. As a result, the terminal can secure scheduling freedom for each scheduled cell instead of using an additional bit equivalent to one antenna port field. Additionally, in a situation where DCI format 1_1 and 1_3 share DMRS-related configuration parameters and 0_1 and 0_3 share the same DMRS-related configuration parameters, the terminal can selectively use an enhanced DMRS type (dmrs-TypeEnh set) and a DMRS type (dmrs-TypeEnh not set) when scheduling based on DCI format 0_1 ​​and 1_1.

[0573] According to one embodiment, a terminal may be notified from a base station of at least one combination of at least one of the above-described [Method 1] to [Method 6] through at least one of upper layer signaling, MAC-CE signaling, or L1 signaling. Alternatively, the terminal may expect to be fixedly defined in at least one of the above-described [Method 1] to [Method 6] specifications.

[0574] According to one embodiment, additionally, when a terminal is notified by a base station of a combination of one or more specific methods through at least one of upper layer signaling, MAC-CE signaling, or L1 signaling, the terminal may be unable to support one or more other specific combinations of methods. For example, if the terminal has not received the DMRS settings described above, the terminal may expect that [Method 1] described above regarding DMRS transmission and reception is fixedly defined in the standard. For example, the terminal may be notified by a base station of [Method 6] described above through at least one of upper layer signaling, MAC-CE signaling, or L1 signaling. In this case, the terminal may identify that it has been notified by the base station that [Method 1] described above is not supported.

[0575] According to one embodiment, a terminal may report to a base station terminal capability including information regarding whether the terminal can support at least one of [Method 1] to [Method 6] described above. In this case, if the terminal reports to the base station terminal capability that a combination of one or more specific methods is supported, it may be considered that the terminal has reported that it cannot support one or more other specific combinations of methods. For example, the terminal may report to the base station whether it can support [Method 1] described above. For example, the terminal may report to the base station that the terminal can support [Method 6] described above, and a terminal capability report regarding the terminal being able to support [Method 6] may mean that the terminal cannot support [Method 1].

[0576] FIG. 13 illustrates a flowchart of the operation of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0577] According to one embodiment, in step 1300, the terminal may transmit terminal capabilities to the base station. The terminal capability signaling that may be reported at this time may relate to at least one of the following: terminal capabilities related to the DMRS type described above, terminal capabilities related to the enhanced DMRS type described above, terminal capabilities related to the search space, terminal capabilities related to supported DCI formats (e.g., DCI formats 0_1, 0_2, 0_3, 1_1, 1_2, 1_3, 4_2), terminal capabilities indicating that simultaneous support between one or more of the supported DCI formats and the enhanced DMRS type is possible, or terminal capabilities indicating whether the above [Method 1] through [Method 6] are supported. Unlike as illustrated in FIG. 13, step 1300 may be omitted.

[0578] According to one embodiment, at step 1305, the terminal may receive upper layer signaling from the base station according to the reported terminal capability. At this time, the terminal may receive from the base station upper layer signaling related to the search space, upper layer signaling related to the DCI format that can be monitored within each search space, upper layer signaling related to the DMRS type and enhanced DMRS type, or upper layer signaling for at least one of the upper layer signaling for [Method 1] to [Method 6] described above.

[0579] According to one embodiment, at step 1310, the terminal may receive DCI format 0_3 or / and 1_3 from the base station and may receive scheduling information for PUSCH transmission or PDSCH reception for one or more cells.

[0580] According to one embodiment, in step 1315, the terminal can interpret the antenna port field in DCI format 0_3 or / and 1_3. At this time, the terminal can determine whether the antenna port field in DCI format 0_3 or / and 1_3 is defined based on type 1a or type 2, and if it is defined as type 1a, the terminal can interpret the antenna port field through a combination of at least one of [Method 1] to [Method 6].

[0581] According to one embodiment, in step 1320, the terminal may interpret fields existing within DCI format 0_3 or / and 1_3, including the antenna port field, to receive PDSCH or transmit PUSCH in each scheduled cell. Upon receiving PDSCH, the terminal may attempt to demodulate and decode the PDSCH data after estimating the demodulation channel based on the PDSCH DMRS according to the interpretation of the antenna port field within DCI format 1_3. Additionally, the terminal may construct and transmit PUSCH DMRS to the base station according to the interpretation of the antenna port field within DCI format 0_3.

[0582] The above-described flowchart illustrates an exemplary method that can be implemented in accordance with the principles of the present disclosure, and various modifications may be made to the method illustrated in the flowchart in this specification. For example, although illustrated as a series of steps in the drawings, the steps or operations illustrated in each drawing may be superimposed, performed in parallel, performed in a different order, or performed repeatedly. Additionally, at least one of the steps included in the flowchart illustrated in the drawings may be omitted or changed to another step.

[0583] FIG. 14 illustrates a flowchart of the operation of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0584] According to one embodiment, at step 1400, the base station may receive terminal capabilities from the terminal. At this time, the terminal capability signaling that may be reported from the terminal to the base station may include information regarding at least one of the following: terminal capabilities related to the DMRS type described above, terminal capabilities related to the enhanced DMRS type described above, terminal capabilities related to the search space, terminal capabilities related to supported DCI formats (e.g., DCI formats 0_1, 0_2, 0_3, 1_1, 1_2, 1_3, 4_2), terminal capabilities indicating that simultaneous support between one or more of the supported DCI formats and the enhanced DMRS type is possible, and terminal capabilities indicating whether the above [Method 1] to [Method 6] are supported. Unlike as illustrated in FIG. 14, step 1400 may be omitted.

[0585] According to one embodiment, in step 1405, the base station may transmit upper layer signaling to the terminal based on the terminal capability received from the terminal in step 1400. At this time, the base station may set to the terminal upper layer signaling related to the search space, upper layer signaling related to the DCI format that can be monitored within each search space, upper layer signaling related to the DMRS type and enhanced DMRS type, or upper layer signaling for at least one combination of the upper layer signaling for [Method 1] to [Method 6].

[0586] According to one embodiment, in step 1410, the base station may transmit DCI format 0_3 or / and 1_3 to the terminal. Additionally, the base station may transmit scheduling information for PUSCH transmission or PDSCH reception to one or more cells to the terminal.

[0587] According to one embodiment, at step 1415, the base station may assume that the terminal interprets the antenna port field in DCI format 0_3 or / and 1_3. At this time, the base station may assume, through the upper layer signaling transmitted to the terminal and at least one of [Method 1] to [Method 6], whether the terminal interprets the antenna port field in DCI format 0_3 or / and 1_3 based on type 1a or type 2.

[0588] According to one embodiment, in step 1420, the base station may transmit PDSCH to the terminal in each scheduled cell or receive PUSCH from the terminal based on the DCI format 0_3 or / and 1_3 transmitted to the terminal in step 1415. When transmitting PDSCH, the base station may construct and transmit PDSCH DMRS to the terminal according to the contents indicated by the Antenna port field in DCI format 1_3. Additionally, the base station may attempt to demodulate and decode PUSCH data and / or UCI after estimating the demodulation channel based on the PUSCH DMRS based on the contents indicated by the Antenna port field in DCI format 0_3.

[0589] The above-described flowchart illustrates an exemplary method that can be implemented in accordance with the principles of the present disclosure, and various modifications may be made to the method illustrated in the flowchart in this specification. For example, although illustrated as a series of steps in the drawings, the steps or operations illustrated in each drawing may be superimposed, performed in parallel, performed in a different order, or performed repeatedly. Additionally, at least one of the steps included in the flowchart illustrated in the drawings may be omitted or changed to another step.

[0590] FIG. 15 illustrates the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0591] Referring to FIG. 15, the terminal may include a transceiver (referring to a terminal receiver (1500) and a terminal transmitter (1510)), a memory (not shown), and a terminal processing unit (1505, or a terminal control unit or processor). Depending on the communication method of the terminal described above, the transceiver (1500, 1510), memory, and terminal processing unit (1505) of the terminal may operate. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more components or fewer components than the components described above. Furthermore, the transceiver, memory, and processor may be implemented in the form of a single chip.

[0592] The transceiver can transmit and receive signals with a base station. Here, the signal may include control information and data. To this end, the transceiver may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts the frequency. However, this is merely one embodiment of the transceiver, and the components of the transceiver are not limited to an RF transmitter and an RF receiver.

[0593] In addition, the transceiver receives a signal through a wireless channel and outputs it to a processor, and can transmit the signal output from the processor through a wireless channel.

[0594] Memory can store programs and data necessary for the operation of the terminal. Additionally, memory can store control information or data included in signals transmitted and received by the terminal. Memory may be composed of storage media or combinations of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD. Additionally, there may be multiple memories.

[0595] Additionally, the processor can control a series of processes to enable the terminal to operate according to the aforementioned embodiment. For example, the processor can receive a DCI composed of two layers and control the components of the terminal to receive multiple PDSCHs simultaneously. There may be multiple processors, and the processors can perform the operation of controlling the components of the terminal by executing a program stored in memory.

[0596] FIG. 16 illustrates the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0597] Referring to FIG. 16, a base station may include a transceiver unit (referring to a base station receiver unit (1600) and a base station transmitter unit (1610)), a memory (not shown), and a base station processing unit (1605, or a base station control unit or processor). Depending on the communication method of the base station described above, the transceiver unit (1600, 1610), the memory, and the base station processing unit (1605) of the base station may operate. However, the components of the base station are not limited to the examples described above. For example, the base station may include more components or fewer components than the components described above. In addition, the transceiver unit, the memory, and the processor may be implemented in the form of a single chip.

[0598] The transceiver can transmit and receive signals with a terminal. Here, the signal may include control information and data. To this end, the transceiver may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts the frequency. However, this is merely one embodiment of the transceiver, and the components of the transceiver are not limited to an RF transmitter and an RF receiver.

[0599] In addition, the transceiver receives a signal through a wireless channel and outputs it to a processor, and can transmit the signal output from the processor through a wireless channel.

[0600] Memory can store programs and data necessary for the operation of the base station. Additionally, memory can store control information or data included in signals transmitted and received by the base station. Memory can be composed of storage media or combinations of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD. Additionally, there may be multiple memories.

[0601] A processor can control a series of processes to enable a base station to operate according to the embodiments of the present disclosure described above. For example, the processor can control each component of the base station to configure two layers of DCIs containing allocation information for a plurality of PDSCHs and to transmit them. There may be multiple processors, and the processors can perform control operations on the components of the base station by executing a program stored in memory.

[0602] Methods according to the claims or embodiments described in the specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0603] When implemented in software, a computer-readable storage medium may be provided for storing one or more programs (software modules). One or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. One or more programs include instructions that cause the electronic device to execute methods according to the claims or embodiments described in the specification of this disclosure.

[0604] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, ROM (Read Only Memory), Electrically Erasable Programmable Read Only Memory (EEPROM), magnetic disc storage devices, Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs), or other forms of optical storage devices, magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these. Additionally, each constituent memory may include multiple units.

[0605] Additionally, the program may be stored on an attachable storage device accessible via a communication network such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination thereof. Such a storage device may be connected to 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 a device performing an embodiment of the present disclosure.

[0606] In the specific embodiments of the present disclosure described above, the components included in the embodiments are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural form, it may be composed of a singular form, and even if a component is expressed in the singular form, it may be composed of a plural form.

[0607] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples provided to facilitate the explanation of the technical content of the present disclosure and to aid in understanding the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is obvious to those skilled in the art that other variations based on the technical concept of the present disclosure are possible. Furthermore, each of the above embodiments may be combined and operated as needed. For example, a base station and a terminal may be operated by combining parts of one embodiment of the present disclosure with parts of another embodiment. For example, a base station and a terminal may be operated by combining parts of the first embodiment and the second embodiment of the present disclosure. In addition, although the above embodiments are presented based on an FDD LTE system, other variations based on the technical concept of the above embodiments may be implemented in other systems such as TDD LTE systems, 5G, or NR systems.

[0608] Meanwhile, the order of description in the drawings illustrating the method of the present disclosure does not necessarily correspond to the order of execution, and the order of execution may be changed or executed in parallel.

[0609] Alternatively, drawings describing the method of the present disclosure may omit some components and include only some components to the extent that the essence of the present disclosure is not impaired.

[0610] Additionally, the method of the present disclosure may be implemented by combining some or all of the contents included in each embodiment to the extent that it does not impair the essence of the present disclosure.

[0611] Various embodiments of the present disclosure have been described above. The foregoing description of the present disclosure is for illustrative purposes only and is not limited to the embodiments disclosed. Those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present disclosure. The scope of the present disclosure is defined by the claims set forth below rather than by the foregoing detailed description, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included within the scope of the present disclosure.

Claims

In a method performed by a terminal (user equipment) in a wireless communication system, the method is: A step of transmitting terminal capability information to a base station regarding the type of enhanced demodulation reference signal (DMRS) and downlink control information (DCI) for scheduling PUSCH for multiple cells; A step of receiving configuration information regarding the enhanced DMRS type and the maximum length of the DMRS from the base station; A step of receiving the DCI including an antenna port field from the base station; and A method comprising the step of identifying a DMRS port indicated by the antenna port field based on the above setting information. In Article 1, A method in which the bit length of the antenna port field is determined as one of 4 bits, 5 bits, or 6 bits based on the enhanced DMRS type and the maximum length of the DMRS set by the setting information. In Article 2, The above-mentioned enhanced DMRS type is set as either the first type or the second type, and The maximum length of the above DMRS is set to either 1 or 2, and A method in which the antenna port field indicates the DMRS port based on one of a plurality of antenna port mapping tables corresponding to a combination of the set enhanced DMRS type and the maximum length of the DMRS. In Paragraph 3, The above-mentioned first type supports up to 8 or 16 orthogonal DMRS ports depending on the number of front-loaded symbols of the DMRS, and A method in which the second type supports up to 12 and 24 orthogonal DMRS ports, respectively, depending on the number of shear-placement symbols. In Paragraph 4, The first type above indicates up to 8 or 16 orthogonal DMRS ports based on 2 CDM groups, 2 TD-OCCs, and 4 FD-OCCs (frequency-domain orthogonal cover codes), and The above second type is a method for indicating up to 12 or 24 orthogonal DMRS ports based on three CDM groups, two TD-OCCs, and four FD-OCCs (time-domain orthogonal cover codes). In Article 1, A method in which the above terminal capability information indicates that the terminal can simultaneously support the enhanced DMRS type and the DCI. In claim 1, the method is: A method further comprising the step of transmitting an uplink DMRS of the enhanced DMRS type to the base station via a PUSCH scheduled by the DCI based on the identified DMRS port. In a method performed by a base station in a wireless communication system, the method is: A step of receiving terminal capability information from a terminal (user equipment) regarding the type of an enhanced DMRS (demodulation reference signal) and DCI (downlink control information) for scheduling PUSCH for multiple cells; A step of transmitting setting information regarding the enhanced DMRS type and the maximum length of the DMRS to the terminal; and A method comprising the step of transmitting the DCI, which includes an antenna port field for indicating a DMRS port, to the terminal. In a wireless communication system, regarding the terminal (user equipment): At least one transceiver; At least one processor communicatively coupled to the above at least one transceiver; and It includes at least one memory that is communicationally coupled to the above at least one processor and stores instructions, and The above instructions are executed individually or in any combination by the above at least one processor, so that the terminal: Transmit terminal capability information to the base station regarding the type of enhanced DMRS (demodulation reference signal) and DCI (downlink control information) for scheduling PUSCH for multiple cells, and Receive configuration information regarding the enhanced DMRS type and the maximum length of the DMRS from the above base station, and Receive the DCI including an antenna port field from the base station, and A terminal that identifies the DMRS port indicated by the antenna port field based on the above setting information. In Article 9, A terminal in which the bit length of the antenna port field is determined as one of 4 bits, 5 bits, or 6 bits based on the enhanced DMRS type set by the setting information and the maximum length of the DMRS. In Article 10, The above-mentioned enhanced DMRS type is set as either the first type or the second type, and The maximum length of the above DMRS is set to either 1 or 2, and A terminal in which the antenna port field indicates the DMRS port based on one of a plurality of antenna port mapping tables corresponding to a combination of the set enhanced DMRS type and the maximum length of the DMRS. In Article 11, The above-mentioned first type supports up to 8 or 16 orthogonal DMRS ports depending on the number of front-loaded symbols of the DMRS, and The second type above is a terminal that supports up to 12 and 24 orthogonal DMRS ports, respectively, depending on the number of shear-placement symbols. In Article 12, The first type above indicates up to 8 or 16 orthogonal DMRS ports based on 2 CDM groups, 2 TD-OCCs, and 4 FD-OCCs (frequency-domain orthogonal cover codes), and The second type above indicates up to 12 or 24 orthogonal DMRS ports based on three CDM groups, two TD-OCCs, and four FD-OCCs (time-domain orthogonal cover codes), a terminal. In Article 9, A terminal whose terminal capability information indicates that the terminal can simultaneously support the enhanced DMRS type and the DCI. In a wireless communication system, regarding a base station: At least one transceiver; At least one processor communicatively coupled to the above at least one transceiver; and It includes at least one memory that is communicationally coupled to the above at least one processor and stores instructions, and The above instructions are executed individually or in any combination by the above at least one processor, so that the base station: Receive terminal capability information from a terminal (user equipment) regarding the type of enhanced DMRS (demodulation reference signal) and DCI (downlink control information) for scheduling PUSCH for multiple cells, and Transmitting configuration information regarding the enhanced DMRS type and the maximum length of the DMRS to the above terminal, and A base station that transmits the DCI, which includes an antenna port field for indicating a DMRS port, to the terminal.

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