Multiple User Space Multiplexing Scheduling Method and Apparatus in Wireless Communication Systems

Abstract

This disclosure relates to 5G or 6G communication systems to support higher data transmission rates. This disclosure relates to the operation of terminals and base stations in wireless communication systems, and more specifically, to a transmission and reception method using spatial multiplexing in a wireless communication system and an apparatus capable of performing this.

Description

[Technical Field]

[0001] This disclosure relates to the operation of terminals and base stations in a wireless communication system. Specifically, this disclosure relates to a multiple user space multiplexing scheduling method and an apparatus for performing this method in a wireless communication system. [Background technology]

[0002] 5G mobile communication technology defines a wide frequency band to enable high transfer speeds and new services, and can be implemented not only in the sub6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band known as millimeter wave (mmWave) such as 28GHz and 39GHz ("Above 6GHz"). Furthermore, 6G mobile communication technology, referred to as a system beyond 5G, is being considered for implementation in the terahertz band (for example, the 95GHz to 3 terahertz (3THz) band) to achieve transfer 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, the goal was to support and meet performance requirements for services such as enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). This included beamforming and Massive MIMO to mitigate path loss and increase transmission distance in the ultra-high frequency band, various numerology support (such as operation of multiple subcarrier spacings) and dynamic operation of slot formats for efficient utilization of ultra-high frequency resources, initial connection technologies to support multiplexed beam transmission and broadband, definition and operation of Band-Width Parts (BWP), new channel coding methods such as Low-Density Parity Check (LDPC) codes for high-capacity data transmission and Polar Code for highly reliable transmission of control information, L2 pre-processing, and network slicing to provide dedicated networks specialized for specific services. Standardization has progressed for techniques such as slicing.

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

[0005] Furthermore, standardization in the field of wireless interface architecture / protocols is underway for technologies such as the Industrial Internet of Things (IIoT) to support new services using collaboration and integration with other industries, Integrated Access and Backhaul (IAB) to provide nodes for expanding 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 RACH for NR to simplify random access procedures.

[0006] Furthermore, standardization is underway in the system architecture / services field for 5G baseline architectures (e.g., Service-based Architecture, Service-based Interface) for connecting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, as well as for Mobile Edge Computing (MEC), where services are provided based on the terminal's location.

[0007] With the commercialization of such 5G mobile communication systems, the explosively increasing number of connected devices will be linked to the communication network. Accordingly, it is expected that enhancements to the functionality and performance of 5G mobile communication systems and the integrated operation of connected devices will be necessary. To this end, new research is planned on improving 5G performance and reducing complexity using augmented reality (eXR), artificial intelligence (AI), and machine learning (ML) to efficiently support augmented reality (AR), virtual reality (VR), and mixed reality (MR), as well as AI service support, metabus service support, and drone communications.

[0008] Furthermore, the development of such 5G mobile communication systems could serve as a foundation for the development of new technologies for 6G mobile communication, including new waveforms to guarantee terahertz band coverage, multiplex antenna transmission technologies such as 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 technologies using Orbital Angular Momentum (OAM), and Reconfigurable Intelligent Surface (RIS) technologies, as well as full duplex technologies to improve the frequency efficiency and system network of 6G mobile communication, satellites, AI-based communication technologies that utilize AI (Artificial Intelligence) from the design stage and internalize end-to-end AI support functions to achieve system optimization, and next-generation distributed computing technologies that realize services of a complexity exceeding the limits of terminal computing power by utilizing ultra-high-performance communication and computing resources.

[0009] The information above is presented solely as background information to aid in understanding the disclosed content. No judgment has been made, nor has any claim been made, regarding whether the above information is applicable as prior art in relation to the disclosed content. [Overview of the project] [Problems that the invention aims to solve]

[0010] The disclosed embodiments aim to provide an apparatus and method that can effectively provide services through spatial multiplexing in a mobile communication system.

[0011] This disclosure is made to address the above-mentioned problems and shortcomings and to provide at least the advantages described below. [Means for solving the problem]

[0012] According to one embodiment of the present disclosure, a method performed by a terminal of a communication system includes the steps of: receiving, via upper-layer signaling, configuration information from a base station indicating that information regarding MU-MIMO (multi-user multi-input and multi-output) is included in DCI (downlink control information); receiving, from the base station, the DCI which schedules downlink data, wherein the DCI includes the information regarding MU-MIMO; and receiving, from the base station, the downlink data based on the information regarding MU-MIMO, wherein a value of 0 for the information regarding MU-MIMO indicates that there are no other terminals scheduled together with the terminal, or that other terminals using a different DMRS (demodulation reference signal) sequence than the terminal have been scheduled.

[0013] According to another embodiment of the present disclosure, a method performed by a base station of a communication system includes the steps of: transmitting configuration information to a terminal via upper-layer signaling indicating that information regarding MU-MIMO (multi-user multi-input and multi-output) is included in the DCI (downlink control information); transmitting the DCI to the terminal for scheduling downlink data, wherein the DCI includes the information regarding MU-MIMO; and transmitting the downlink data to the terminal, wherein a value of 0 for the information regarding MU-MIMO indicates that there are no other terminals scheduled with the terminal, or that other terminals using a different DMRS (demodulation reference signal) sequence than the terminal have been scheduled.

[0014] According to yet another embodiment of the present disclosure, a terminal of a communication system includes a receiving unit, which receives, via upper-layer signaling, configuration information from a base station indicating that information regarding MU-MIMO (multi-user multi-input and multi-output) is included in DCI (downlink control information), and a control unit configured to receive the DCI from the base station for scheduling downlink data, wherein the DCI includes the information regarding MU-MIMO, and the control unit is configured to receive the downlink data from the base station based on the information regarding MU-MIMO, wherein a value of 0 for the information regarding MU-MIMO indicates that there are no other terminals scheduled together with the terminal, or that other terminals using a different DMRS (demodulation reference signal) sequence than the terminal have been scheduled.

[0015] According to yet another embodiment of the present disclosure, a base station of a communication system includes a transceiver unit and a control unit that transmits to a terminal via upper-layer signaling configuration information indicating that information regarding MU-MIMO (multi-user multi-input and multi-output) is included in the DCI (downlink control information), and transmits to the terminal the DCI for scheduling downlink data, wherein the DCI includes the information regarding MU-MIMO and is configured to transmit the downlink data to the terminal, wherein a value of 0 for the information regarding MU-MIMO indicates that there are no other terminals scheduled together with the terminal, or that other terminals using a different DMRS (demodulation reference signal) sequence than the terminal have been scheduled.

[0016] Before beginning the following detailed explanation, it would be helpful to provide definitions of the specific words and syntax used throughout this patent document. The terms “include” and “comprise” and their derivatives mean to include without restriction. The term “or” is comprehensive and means “and / or.” The terms "associated with" and "associated with therwith," and their derivatives, can mean "include," "be included within," "interconnect with," "contain," "be contained within," "connect to or with," "couple to or with," "be communicable with," "cooperate with," "interleave," "juxtapose," "be proximate to," "be bound to or with," "have," "have a property of," etc. The term "controller" means any device, system, or part thereof that controls at least one operation, and such device may be embodied by hardware, firmware, or software, or a combination of two or more of these. It should be noted that the functions associated with a particular controller may be centralized locally or remotely, or distributed.

[0017] Furthermore, the various functions described below may be embodied or supported by one or more computer programs, each program consisting of computer-readable program code and embodied in computer-readable media. The terms “application” and “program” refer to one or more computer programs, software components, instruction sets, procedures, functions, objects, classes, instances, associated data, or parts thereof applied to be embodied in appropriate computer-readable program code. The term “computer-readable program code” includes all types of computer code, including source code, object code, and executable code. The term “computer-readable media” includes all types of media that a computer can access, such as read-only memory (ROM), random-access memory (RAM), hard disk drives, compact discs (CDs), digital video discs (DVDs), or other types of memory. “Non-temporary” computer-readable media excludes wired, wireless, optical, or other communication links that transmit temporary electrical or other signals. Non-temporary computer-readable media include media that can permanently store data and media that store data but can be overwritten later (e.g., re-recordable optical discs or deleteable memory devices).

[0018] While definitions of certain words and phrases are provided throughout this patent document, those skilled in the art should understand that, in many cases (though not always), such definitions apply not only to prior use but also to future use of the defined words and phrases. [Effects of the Invention]

[0019] The embodiments of the disclosure provide an apparatus and method that can effectively provide services by transmitting and receiving data through spatial multiplexing in a mobile communication system. [Brief explanation of the drawing]

[0020] Other aspects, features, and advantages of the foregoing and the present disclosure will become more apparent from the following detailed description, which will be considered in conjunction with the accompanying drawings.

[0021] [Figure 1] This figure shows the basic structure in the time-frequency domain of a wireless communication system according to one embodiment of the present disclosure.

[0022] [Figure 2] This diagram shows the structure of a frame, subframe, and slot in a wireless communication system according to one embodiment of the present disclosure.

[0023] [Figure 3] This figure shows an example of bandwidth partial setting in a wireless communication system according to one embodiment of the present disclosure.

[0024] [Figure 4] This figure shows an example of setting the control area of ​​a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.

[0025] [Figure 5] This figure shows the structure of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.

[0026] [Figure 6] This figure shows an example of frequency axis resource allocation for PDSCH or PUSCH in a wireless communication system according to one embodiment of the present disclosure.

[0027] [Figure 7] This figure shows the VRB-PRB interleaving method of the PDSCH during FDRA type-1 resource allocation according to one embodiment of the present disclosure.

[0028] [Figure 8] This figure shows an example of time-axis resource allocation for a PDSCH in a wireless communication system according to one embodiment of the present disclosure.

[0029] [Figure 9] This diagram shows the process for beam setting and activation of the PDSCH.

[0030] [Figure 10] This figure shows an example of antenna port configuration and resource allocation for cooperative communication in a wireless communication system according to one embodiment of the present disclosure.

[0031] [Figure 11] This figure shows an example of the configuration of downlink control information (DCI) for cooperative communication in a wireless communication system according to one embodiment of the present disclosure.

[0032] [Figure 12] This figure shows the Enhanced PDSCH TCI state activation / deactivation MAC-CE structure.

[0033] [Figure 13] This figure shows an example of an MC-DCI according to one embodiment of the present disclosure that includes multiple FDRA fields.

[0034] [Figure 14] This figure shows 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.

[0035] [Figure 15] This figure shows an example of a field that indicates frequency domain resource allocation information based on the subcarrier interval of a cell according to one embodiment of the present disclosure.

[0036] [Figure 16] This figure shows the operation of a terminal according to one embodiment of the present disclosure.

[0037] [Figure 17] This figure shows the operation of a base station according to one embodiment of the present disclosure.

[0038] [Figure 18] This figure shows the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0039] [Figure 19] This figure shows the structure of a base station in a wireless communication system according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0040] Figures 1 to 19 discussed below, and the various embodiments used in this patent document to illustrate the principles of the present invention, are merely illustrative and should not be construed as limiting the scope of the invention. Those skilled in the art will understand that the principles of the present invention can be embodied in any appropriately configured system or apparatus.

[0041] The embodiments of this disclosure will be described in detail below with reference to the accompanying drawings.

[0042] In describing the embodiments, we will omit explanations of technical content that is already well known in the art to which this disclosure pertains and is not directly related to this disclosure. This is to ensure that the gist of this disclosure is conveyed more clearly without becoming ambiguous by omitting unnecessary explanations.

[0043] For similar reasons, some components in the attached drawings are exaggerated, omitted, or shown schematically. Furthermore, the dimensions of each component do not fully reflect their actual size. In each drawing, identical or corresponding components are given the same reference number.

[0044] The advantages and features of this disclosure, as well as the methods for achieving them, will become clearer by referring to the embodiments described below in detail with the accompanying drawings. However, this disclosure is not limited to the embodiments disclosed below and may be embodied in a variety of different forms, which are provided merely to complete the disclosure and to fully inform a person of ordinary skill in the art to which this disclosure pertains, and this disclosure is defined solely by the claims. Throughout the specification, the same reference numerals refer to the same components. In addition, in describing this disclosure, if it is determined that a specific description of a relevant function or configuration would obscure the essence of this disclosure, such detailed description will be omitted. Furthermore, the terms described below are defined in consideration of the function in this disclosure, and these may differ depending on the intent or convention of the user or operator. Therefore, their definitions should be based on the content throughout this specification.

[0045] Hereinafter, a base station is the entity responsible for allocating resources to terminals and may be at least one of gNode B, eNode B, Node B, BS (Base Station), radio connection unit, base station controller, or node on the network. Terminals may include UE (User Equipment), MS (Mobile Station), cellular phones, smartphones, computers, or multimedia systems capable of performing communication functions. In this disclosure, Downlink (DL) refers to the radio transmission path of signals transmitted from a base station to a terminal, and Uplink (UL) refers to the radio transmission path of signals transmitted from a terminal to a base station. Furthermore, while LTE or LTE-A systems may be described below as examples, embodiments of this disclosure may also be applied to other communication systems having a similar technical background or channel configuration. For example, this may include fifth-generation mobile communication technologies (5G, new radio, NR) developed after LTE-A, and 5G below may be a concept that includes existing LTE, LTE-A, and other similar services. Furthermore, this disclosure may be applied to either FDD (frequency division duplex) or TDD (timef division duplex) systems. In addition, this disclosure may be applied to other communication systems with some modifications, without departing from the scope of this disclosure, at the discretion of a person with skilled technical knowledge.

[0046] At this point, it can be understood that each block in the processing flow diagram and combinations of the flow diagram can be executed by computer program instructions. Since these computer program instructions can be installed on the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, the instructions performed by the processor of the computer or other programmable data processing device will generate means for performing the functions described in the blocks of the flow diagram. These computer program instructions can also be stored in computer-available or computer-readable memory that can be directed to the computer or other programmable data processing device to embody the functions in a particular manner, and therefore, the instructions stored in such computer-available or computer-readable memory can also produce manufactured articles that contain instruction means for performing the functions described in the blocks of the flow diagram. Computer program instructions can also be installed on a computer or other programmable data processing device, and therefore, instructions that perform a series of operational steps on a computer or other programmable data processing device to generate a process executed on the computer and cause the computer or other programmable data processing device to execute can also provide steps for performing the functions described in the blocks of the flow diagram.

[0047] Furthermore, each block may represent a module, segment, or portion of code containing one or more executable instructions for performing a specified logical function. It should be noted that in some alternative execution examples, the functions mentioned in a block may occur out of order. For example, two blocks illustrated consecutively may actually be executed substantially simultaneously, or they may sometimes be executed in reverse order depending on the function in question.

[0048] In this embodiment, the term "~part" refers to either software or a hardware component such as an FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and "~part" can perform either role. However, "~part" is not limited to software or hardware. "~part" may be configured to reside on an addressable storage medium and may be configured to regenerate one or more processors. As an example, "~part" includes a group of 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 by the components and "~part" can be combined into fewer components and "~part," or further separated into additional components and "~part." Furthermore, the components and "~part" may be embodied to regenerate one or more CPUs within a device or security multimedia card. In this embodiment, "~part" may include one or more processors.

[0049] Wireless communication systems have moved beyond their early voice-centric service models and evolved into broadband wireless communication systems that provide high-speed, high-quality packet data services, such as 3GPP's HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2's HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE's 802.16e.

[0050] As a representative example of the aforementioned broadband wireless communication system, the LTE system employs the OFDM (Orthogonal Frequency Division Multiplexing) method for the downlink (DL) and the SC-FDMA (Single Carrier Frequency Division Multiple Access) method for the uplink (UL). The uplink refers to the radio link on which a terminal (UE (User Equipment) or MS (Mobile Station)) transmits data or control signals to a base station (eNode B or base station (BS)), while the downlink refers to the radio link on which a base station transmits data or control signals to a terminal. In such multiplexing methods, the data or control information for each user can usually be distinguished by allocating and operating the time-frequency resources for carrying data or control information for each user in such a way that they do not overlap, i.e., orthogonality is maintained.

[0051] As a future communication system following LTE, namely the 5G communication system, it must be able to freely reflect the diverse requirements of users and service providers, and services that can simultaneously satisfy these diverse requirements must be supported. Services to be considered for the 5G communication system include enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable low-latency communication (URLLC).

[0052] eMBB aims to provide data transfer speeds that are even higher than those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB needs to be able to provide a maximum data transfer speed of 20 Gbps on the downlink and a maximum data transfer speed of 10 Gbps on the uplink from the perspective of a single base station. In addition, a 5G communication system must provide not only the maximum data transfer speed but also an increased user-perceived data transfer speed. Meeting these requirements necessitates improvements in various transmission and reception technologies, including more advanced Multi-Input Multi-Output (MIMO) transmission technology. Furthermore, while LTE transmits signals using a maximum transmission bandwidth of 20 MHz in the 2 GHz band, a 5G communication system can meet the data transfer speed requirements by using a wider frequency bandwidth than 20 MHz in the 3-6 GHz or above frequency band.

[0053] Simultaneously, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide the Internet of Things, mMTC requires features such as support for connecting large numbers of devices within a cell, improved device coverage, extended battery life, and reduced device costs. Since the Internet of Things involves various sensors and devices providing communication capabilities, a large number of devices (e.g., 1,000,000 devices / km) are required within a cell. 2 It must be able to support mMTC. Also, due to the nature of the service, terminals supporting mMTC are likely to be located in shaded areas where cells cannot cover, such as the basements of buildings, and therefore may require wider coverage compared to other services provided in 5G communication systems. Terminals supporting mMTC should consist of low-cost terminals, and because it is difficult to frequently replace the terminal batteries, a very long battery life of 10 to 15 years may be required.

[0054] Finally, URLLC is a cellular-based wireless communication service used for specific purposes (mission-critical). Examples include services used for remote control of robots or machinery, industrial automation, unmanned aerial vehicles, remote health care, and emergency alerts. Therefore, the communication provided by URLLC must offer extremely low latency and very high reliability. For example, services supporting URLLC must meet an air interface latency of less than 0.5 milliseconds and simultaneously handle 10 -5 The following packet error rate requirements apply. Therefore, for services supporting URLLC, 5G systems must provide a smaller transmit time interval (TTI) compared to other services, and design considerations may require allocating a wide range of resources in the frequency band to ensure the reliability of the communication link.

[0055] The three 5G services, namely eMBB, URLLC, and mMTC, may be multiplexed and transmitted within a single system. In this case, different transmission and reception methods and parameters may be used between the services to satisfy the different requirements of each service. Of course, 5G is not limited to these three services.

[0056] Hereafter, a / b may be understood as at least one of a or b.

[0057] The frame structure of the 5G system will be explained in more detail below, with reference to the diagrams.

[0058] Figure 1 shows the basic structure of the time-frequency domain, which is the radio resource area to which data or control channels are transmitted in a 5G system.

[0059] In Figure 1, the horizontal axis 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 may be defined as 1 OFDM symbol 102 on the time axis and 1 subcarrier 103 on the frequency axis. In the frequency domain...

number

[0060] Figure 2 shows the structure of frames, subframes, and slots in a 5G system.

[0061] Figure 2 shows an example of the structure of a frame 200, a subframe 201, and a slot 202. One frame 200 may be defined as 10ms. One subframe 201 may be defined as 1ms, and therefore, one frame 200 may consist of a total of 10 subframes 201. One slot 202,203 may be defined as having 14 OFDM symbols (i.e., the number of symbols per slot).

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number

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[0062] [Table 1]

[0063] Next, the Bandwidth Part (BWP) setting in a 5G communication system will be explained in detail with reference to the diagram.

[0064] Figure 3 shows an example of bandwidth partial setting in a wireless communication system according to one embodiment of the present disclosure.

[0065] Figure 3 shows an example where the terminal bandwidth (UE bandwidth) 300 is configured into two bandwidth portions, namely bandwidth portion #1 (BWP#1) 301 and bandwidth portion #2 (BWP#2) 302. The base station can configure one or more bandwidth portions for a terminal and set the information in Table 2 below for each bandwidth portion.

[0066] [Table 2]

[0067] Of course, the examples above are not exhaustive, and various parameters related to bandwidth portions may be set on the terminal in addition to the configuration information described above. This information can be transmitted from the base station to the terminal by higher-layer signaling, such as RRC (Radio Resource Control) signaling. At least one of the configured bandwidth portions may be activated. Whether or not a configured bandwidth portion is activated may be transmitted from the base station to the terminal quasi-statically by RRC signaling, or dynamically by DCI.

[0068] In some embodiments, the terminal before RRC connection may have its initial bandwidth portion (Initial BWP) for initial connection set by the base station in the Master Information Block (MIB). Furthermore, during the initial connection phase, the terminal can receive setting information for the Control Resource Set (CORESET) and Search Space via the MIB on the PBCH, which can transmit a PDCCH for receiving system information necessary for initial connection (which may correspond to Remaining System Information (RMSI) or System Information Block 1 (SIB1)). The control area and search space set by the MIB may each be considered as Identity (ID) 0. The base station can use the MIB to notify the terminal of setting information such as frequency allocation information, time allocation information, and numerology for control area #0. The base station can also use the MIB to notify the terminal of setting information for the monitoring period and monitoring occasion for control area #0, i.e., setting information for search space #0. The terminal can consider the frequency domain set in control area #0 obtained from the MIB as the initial bandwidth portion for initial connection. In this case, the identifier (ID) of the initial bandwidth portion may be considered as 0. In addition to receiving the SIB, the initial bandwidth portion may be used for other system information (OSI), paging, and random access.

[0069] If a terminal has one or more bandwidth parts configured, the base station can instruct the terminal to change (or switch, transition) a bandwidth part using the Bandwidth Part Indicator field in the DCI. For example, in Figure 3, if the terminal's currently activated bandwidth part is Bandwidth Part #1 301, the base station can instruct the terminal to use Bandwidth Part #2 302 as the Bandwidth Part Indicator in the DCI, and the terminal can change its bandwidth part to Bandwidth Part #2 302, which was indicated as the Bandwidth Part Indicator in the DCI that it received.

[0070] As mentioned above, DCI-based bandwidth portion changes can be instructed by a DCI that schedules a PDSCH or PUSCH. Therefore, when a terminal receives a bandwidth portion change request, it must be able to smoothly receive or transmit the PDSCH or PUSCH scheduled by that DCI using the changed bandwidth portion. For this purpose, the standard specifies requirements for the time by which bandwidth portions are changed (TBWP), which may be defined, for example, as shown in Table 3 below.

[0071] [Table 3]

[0072] The requirements for bandwidth partial delay time support either Type 1 or Type 2, depending on the terminal's capability. The terminal can report to the base station the bandwidth partial delay time type it can support.

[0073] According to the aforementioned requirements for bandwidth portion change delay time, when a terminal receives a DCI containing a bandwidth portion change indicator in slot n, the terminal changes to the new bandwidth portion indicated by the bandwidth portion change indicator in slot n+T BWPThe process can be completed at a time no later than the change in bandwidth, and transmission and reception can be performed on the data channel scheduled by the DCI using the new bandwidth portion. When the base station attempts to schedule a data channel using the new bandwidth portion, the terminal bandwidth portion change delay time (T BWP The time domain resource allocation for a data channel can be determined by taking into consideration the bandwidth portion change delay time. That is, when a base station schedules a data channel with a new bandwidth portion, the method for determining the time domain resource allocation for a data channel can be such that the data channel is scheduled after the bandwidth portion change delay time. As a result, the terminal can determine that the DCI instructing the bandwidth portion change is set to the bandwidth portion change delay time (T BWP You do not need to expect to specify a slot offset (K0 or K2) value smaller than ).

[0074] If a terminal receives a DCI (e.g., DCI format 1_1 or 0_1) that indicates a partial bandwidth change, the terminal does not need to transmit or receive anything in the time interval from the third symbol of the slot that received the PDCCH containing the DCI to the start of the slot indicated by the slot offset (K0 or K2) value indicated in the time domain resource allocation indicator field within the DCI. For example, if a terminal receives a DCI instructing a partial bandwidth change in slot n, and the slot offset value indicated in the DCI is K, the terminal does not need to transmit or receive anything from the third symbol of slot n to the previous symbol of slot n+K (i.e., the last symbol of slot n+K-1).

[0075] Next, we will specifically explain downlink control information (DCI) in 5G systems.

[0076] 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 PUSCH or PDSCH for both fallback and non-fallback DCI formats. The fallback DCI format may consist of fixed fields predefined between the base station and the terminal, while the non-fallback DCI format may include configurable fields.

[0077] DCI messages may be transmitted over the Physical Downlink Control Channel (PDCCH) via channel coding and modulation. A Cyclic Redundancy Check (CRC) is attached to the DCI message payload, and the CRC may be scrambled with 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 terminal-specific data transmission, power control commands, or random access responses. That is, the RNTI is not explicitly transmitted but is included in the CRC calculation process. Upon receiving a DCI message transmitted over the PDCCH, the terminal checks the CRC using its assigned RNTI, and if the CRC check is correct, the terminal knows that the message was sent to it.

[0078] For example, a DCI that schedules a PDSCH for System Information (SI) may be scrambled with SI-RNTI. A DCI that schedules a PDSCH for RAR (Random Access Response) messages may be scrambled with RA-RNTI. A DCI that schedules a PDSCH for Paging messages may be scrambled with P-RNTI. A DCI that notifies SFI (Slot Format Indicator) may be scrambled with SFI-RNTI. A DCI that notifies TPC (Transmit Power Control) may be scrambled with TPC-RNTI. A DCI that schedules a terminal-specific PDSCH or PUSCH may be scrambled with C-RNTI (Cell RNTI).

[0079] DCI format 0_0 may be used as an alternative DCI for scheduling PUSCH, in which case the CRC may be scrambled with C-RNTI. DCI format 0_0 with CRC scrambled with C-RNTI may include, for example, the information in Table 4 below.

[0080] [Table 4]

[0081] DCI format 0_1 ​​may be used as a non-substitute DCI for scheduling PUSCH, in which case the CRC may be scrambled with C-RNTI. DCI format 0_1 ​​with CRC scrambled with C-RNTI may include, for example, the information in Table 5 below.

[0082] [Table 5-1] [Table 5-2]

[0083] DCI format 1_0 may be used as an alternative DCI for scheduling PDSCH, in which case the CRC may be scrambled with C-RNTI. DCI format 1_0 with CRC scrambled with C-RNTI may include, for example, the information in Table 6 below.

[0084] [Table 6]

[0085] DCI format 1_1 may be used as a non-substitute DCI for scheduling PDSCH, in which case the CRC may be scrambled with C-RNTI. DCI format 1_1 with CRC scrambled with C-RNTI may include, for example, the information in Table 7 below.

[0086] [Table 7-1] [Table 7-2]

[0087] The downlink control channel in a 5G communication system will be explained in more detail below with reference to the diagrams.

[0088] Figure 4 shows an example of a Control Resource Set (CORESET) to which a downlink control channel is transmitted in a 5G system. Figure 4 shows an example in which the terminal bandwidth portion (UE bandwidth part) 410 is on the frequency axis and two control areas (control area #1 401, control area #2 402) are set within one slot 420 on the time axis. Control areas 401 and 402 may be set in a specific frequency resource 403 within the overall terminal bandwidth portion 410 along the frequency axis. Along the time axis, they may be set in one or more OFDM symbols, which can be defined as the control area length (Control Resource Set Duration, 404). Referring to the example shown in Figure 4, control area #1 401 is set to have a control area length of 2 symbols, and control area #2 402 is set to have a control area length of 1 symbol.

[0089] In the aforementioned 5G, the control area can be set by the base station on the terminal using higher-layer signaling (e.g., System Information, MIB (Master Information Block), RRC (Radio Resource Control) signaling). Setting a control area on the terminal means providing information such as the control area identifier (Identity), the frequency position of the control area, and the symbol length of the control area. For example, this may include the information shown in Table 8 below.

[0090] [Table 8-1] [Table 8-2]

[0091] In Table 8, the tci-StatesPDCCH (simply named TCI (Transmission Configuration Indication) state) configuration information may include information on one or more SS (Synchronization Signal) / PBCH (Physical Broadcast Channel) block indices or CSI-RS (Channel State Information Reference Signal) indices that are in a QCL (Quasi Co-located) relationship with the DMRS transmitted in the corresponding control domain.

[0092] Figure 5 shows an example of a basic unit of time and frequency resources that constitutes a downlink control channel usable in a 5G system. According to Figure 5, the basic unit of time and frequency resources that constitutes a control channel may be defined as a REG (Resource Element Group, 503), and a 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 can configure a downlink control channel allocation unit by connecting REG 503s.

[0093] As shown in Figure 5, if the basic unit to which a downlink control channel is assigned is called a CCE (Control Channel Element, 504), then one CCE 504 may consist of multiple REGs 503. Taking the REG 503 shown in Figure 5 as an example, a REG 503 may consist of 12 REs, and if one CCE 504 consists of 6 REGs 503, then one CCE 504 may consist of 72 REs. When a downlink control area is established, that area may consist of multiple CCEs 504, and a specific downlink control channel may be mapped to one or more CCEs 504 and transmitted according to the Aggregation Level (AL) within the control area. The CCEs 504 within the control area are distinguished by numbers, and in this case, the numbers of the CCEs 504 may be given by a logical mapping scheme.

[0094] The basic unit of a downlink control channel, namely REG 503, shown in Figure 5, may include both an RE to which the DCI is mapped and an area to which the DMRS505, a reference signal for decoding it, is mapped. As shown in Figure 5, three DMRS505s may be transmitted within one REG 503. The number of CCEs required to transmit a PDCCH may be 1, 2, 4, 8, or 16, depending on the Aggregation Level (AL), and different numbers of CCEs may be used to embody link adaptation of the downlink control channel. For example, when AL=L, one downlink control channel may be transmitted with L CCEs. The terminal must detect the signal without knowing information about the downlink control channel, but a search space representing the set of CCEs is defined for blind decoding. A search space is a set of downlink control channel candidates consisting of CCEs that a terminal should attempt to decode at a given integration level. Since there are various integration levels in which one bundle consists of 1, 2, 4, 8, or 16 CCEs, a terminal can have multiple search spaces. A search space set may be defined as the set of search spaces at all configured integration levels.

[0095] The search space may be classified into a common search space and an UE-specific search space. A certain group of terminals or all terminals can examine the common search space of the PDCCH to receive cell-common control information such as dynamic scheduling and paging messages for system information. For example, PDSCH scheduling assignment information for sending SIBs, including cell operator information, can be received by examining the common search space of the PDCCH. The common search space may be defined as a set of pre-agreed CCEs, where a certain group of terminals or all terminals must receive the PDCCH. Scheduling assignment information for UE-specific PDSCHs or PUSCHs may be received by examining the UE-specific search space of the PDCCH. The UE-specific search space may be defined UE-specifically as a function of the terminal's identity and various system parameters.

[0096] Parameters for the search space for PDCCH may be set from the base station to the terminal using higher-layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station can set on the terminal the number of PDCCH candidate groups at each integration level L, the monitoring period for the search space, the monitoring occasions for the search space at the symbol level within a slot, 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 area index to be monitored in the search space. For example, this may include the information in Table 9 below.

[0097] [Table 9-1] [Table 9-2]

[0098] Depending on the configuration information, the base station can set one or more search space sets on a terminal. In some embodiments, the base station can set search space set 1 and search space set 2 on a terminal, configure search space set 1 to monitor DCI format A scrambled with X-RNTI in a common search space, and configure search space set 2 to monitor DCI format B scrambled with Y-RNTI in a terminal-specific search space.

[0099] According to the configuration information, there may be one or more search space sets in the common search space or the terminal-specific search space. For example, search space set #1 and search space set #2 may be set as the common search space, and search space set #3 and search space set #4 may be set as the terminal-specific search space.

[0100] In the common search space, the following combinations of DCI format and RNTI may be monitored. Of course, this is not limited to the examples below.

[0101] -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

[0102] -DCI format 2_0 with CRC scrambled by SFI-RNTI

[0103] -DCI format 2_1 with CRC scrambled by INT-RNTI

[0104] -DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0105] -DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0106] In the terminal identification search space, the following combinations of DCI format and RNTI may be monitored. Of course, this is not limited to the examples below.

[0107] -DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0108] -DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0109] The explicitly stated RNTI may be used in accordance with the definitions and uses described below.

[0110] C-RNTI (Cell RNTI): Terminal-specific PDSCH scheduling application

[0111] TC-RNTI (Temporary Cell RNTI): For terminal-specific PDSCH scheduling applications.

[0112] CS-RNTI (Configured Scheduling RNTI): A quasi-statically configured terminal-specific PDSCH scheduling application.

[0113] RA-RNTI (Random Access RNTI): Used for PDSCH scheduling during the random access phase.

[0114] P-RNTI (Paging RNTI): Used for PDSCH scheduling where paging is sent.

[0115] SI-RNTI (System Information RNTI): Used for PDSCH scheduling where system information is transmitted.

[0116] INT-RNTI (Interruption RNTI): Used to indicate whether or not puncture is occurring in the PDSCH.

[0117] TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Application of power control command instructions to PUSCH.

[0118] TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Application of power control command instructions for PUCCH.

[0119] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Application of power control command instructions to SRS.

[0120] The aforementioned specified DCI format may follow the definitions in Table 10 below.

[0121] [Table 10]

[0122] In the case of a 5G system, the search space of the integration level L in CORESET p and search space set s may be expressed as shown in equation 1 below.

[0123]

number

[0124] - L: Integrated level

[0125] - n CI Career Index

[0126] - n CCE,p :Total number of CCEs present in CORESET p

[0127]

Number

[0128]

Number

[0129]

Number

[0130] - l = 0, ..., L - 1

[0131] -

Number

[0132] - n RNTI : Terminal identifier

[0133]

Number

[0134]

Number

[0135] In 5G, multiple search space sets can be configured with different parameters (for example, the parameters in Table 9), so the set of search space sets monitored by the terminal can differ at each point in time. For example, if search space set #1 is configured with an X-slot period and search space set #2 is configured with a Y-slot period, and X and Y are different, the terminal can monitor both search space set #1 and search space set #2 in a particular slot, and monitor either search space set #1 or search space set #2 in a particular slot.

[0136] Next, we will explain frequency domain resource assignment (FDRA) for PDSCH (Physical Downlink Shared Channel) and PUSCH (Physical Uplink Shared Channel) in NR.

[0137] Figure 6 shows an example of frequency axis resource allocation for PDSCH or PUSCH in a wireless communication system according to one embodiment of the present disclosure.

[0138] Figure 6 shows three frequency axis resource allocation methods that can be configured at the upper layer in an NR wireless communication system: FDRA type 0 600, FDRA type 1 605, and dynamic switch 610.

[0139] Referring to Figure 6, if the terminal is configured to use only FDRA type 0 by upper layer signaling (600), some downlink control information (DCI) that schedules PDSCH or PUSCH for that terminal will be N RBG It includes a bitmap composed of N bits. The conditions for this will be explained again later. In this case, RBGThis refers to the number of resource block groups (RBGs) determined by the size of the bandwidth portion allocated by the bandwidth indicator and the upper-layer parameter rbg-Size, as shown in Table 11 below. Data is sent to the RBGs that are displayed as 1 in the bitmap.

[0140] [Table 11]

[0141] The size of the frequency resource in the bandwidth portion can be defined as the number of RBs contained in the bandwidth portion. More specifically, if a terminal is instructed to allocate an FDRA type-0 resource, the length of the FDRA field in the DCI received by the terminal is the number of RBGs (N) in the bandwidth portion. RBG ) is identical to,

number

number

number

number

number

[0142] If a terminal is configured to use only FDRA type 1 via upper-layer signaling (605), the DCI that assigns PDSCH or PUSCH to that terminal will

number

number

[0143] If a terminal is not configured with the upper-layer signaling vrb-ToPRB-Interleaver, the terminal can concatenate resources allocated to the VRB to the PRB without interleaving. If a terminal is configured with the upper-layer signaling vrb-ToPRB-Interleaver, the upper-layer signaling has a value of 2 or 4, which may be the unit of multiple RBs performing interleaving. That is, RB bundles of 2 or 4 may be used for interleaving.

[0144] If the device

number

number

number

[0145] - In the i-th BWP, the first RB bundle is

number

[0146] - In the i-th BWP, the last RB bundle, if

number

number

[0147] - In the i-th BWP, the remaining RB bundle is L i It may consist of individual RBs.

[0148] In this case, the VRB may be connected to the PRB by the following method.

[0149] - The last VRB bundle may be concatenated to the last PRB bundle.

[0150] - j-th (j=0,1,...,N) bundle -2) A VRB bundle may be concatenated to the f(j)th PRB bundle, where f(j) can be expressed as shown in equation 2 below.

[0151]

number

[0152] Figure 7 shows the VRB-PRB interleaving method of the PDSCH during FDRA type-1 resource allocation according to one embodiment of the present disclosure. In Figure 7, the case where the first and last VRB bundles (710) consist of one VRB each within a BWP (700) consisting of 10 RBs. Therefore, the number of VRB bundles is N. bundle It may be 6, and by the above formula 2

number

[0153] If a terminal is configured by upper-layer signaling to use both FDRA type-0 resource allocation and FDRA type-1 resource allocation (610), some DCIs that assign PDSCH / PUSCH to the terminal include frequency axis resource allocation information consisting of the larger bit (635) of the payload (615) for setting up FDRA type-0 resource allocation and the payload (620, 625) for setting up FDRA type-1 resource allocation. The conditions for this will be explained again later. In this case, one bit may be added to the beginning (MSB) of the frequency axis resource allocation information in the DCI, and if the value of this bit is "0", it indicates that FDRA type-0 resource allocation should be used, and if the value is "1", it indicates that FDRA type-1 resource allocation should be used.

[0154] If a terminal is configured with an FDRA type-2 resource allocation method via upper-layer signaling, the terminal may be instructed by the base station regarding the FDRA type-2 resource allocation method in the following manner.

[0155] The terminal may be instructed by the base station to provide an interlaced index set containing M RB allocation information.

[0156] Interlace Index

number

[0157] [Table 12]

[0158] Interlace m and bandwidth portion i are RB

number

number

[0159]

number

[0160] Here,

number

[0161] When the subcarrier interval is 15kHz (u=0), RB allocation information for the interlace set may be notified from the base station to the terminal using the m0+l index. Furthermore, the resource allocation field may consist of a Resource Indivation Value (RIV).

number

[0162]

number

number

[0163] [Table 13]

[0164] When the subcarrier interval is 30 kHz (u=1), RB allocation information may be notified from the base station to the terminal in the form of a bitmap indicating the interlace assigned to the terminal. The size of the bitmap is M, and each bit of the bitmap corresponds to an interlace. The order of the interlace bitmap may be such that interlace indices 0 to M-1 are mapped from MSB to LSB.

[0165] Also, for 15kHz and 30kHz, the least significant bit (LSB) of the FDRA field

number

Number

Number

Number

[0166]

Number

[0167]

Number

[0168] Hereinafter, a time-domain resource allocation method for data channels in a 5G system will be described.

[0169] A base station can configure tables for time-domain resource allocation information for downlink data channels (PDSCH) and uplink data channels (PUSCH) on terminals using upper-layer signaling (e.g., RRC signaling). For PDSCH, a table consisting of a maximum of maxNrofDL-Allocations=16 entries may be configured, and for PUSCH, a table consisting of a maximum of maxNrofUL-Allocations=16 entries may be configured. In one embodiment, the time domain resource allocation information may include PDCCH-to-PDSCH slot timing (corresponding to the time interval in slot units between the time a PDCCH is received and the time a PDSCH scheduled by the received PDCCH is transmitted; denoted as K0), PDCCH-to-PUSCH slot timing (corresponding to the time interval in slot units between the time a PDCCH is received and the time a PUSCH scheduled by the received PDCCH is transmitted; denoted as K2), information regarding the position and length of the start symbol in which a PDSCH or PUSCH is scheduled within the slot, and the mapping type of the PDSCH or PUSCH. For example, information like that shown in Table 14 or Table 15 below may be transmitted from the base station to the terminal.

[0170] [Table 14]

[0171] [Table 15]

[0172] The base station can notify the terminal of one of the table entries for the time-domain resource allocation information described above via L1 signaling (e.g., DCI) (for example, indicated in the "Time-Domain Resource Allocation" field within the DCI). Based on the DCI received from the base station, the terminal can obtain the time-domain resource allocation information for the PDSCH or PUSCH.

[0173] Figure 8 shows an example of time-axis resource allocation for a PDSCH in a wireless communication system according to one embodiment of the present disclosure.

[0174] Referring to Figure 8, the base station uses the upper layer to configure the data channel and control channel with subcarrier spacing (SCS) (μ PDSCH ,μ PDCCH The time axis position of a PDSCH resource can be indicated by the scheduling offset (K0) value, and the OFDM symbol start position (800) and length (805) within a single slot, which are dynamically indicated by DCI.

[0175] Next, the beam configuration method for the PDSCH will be described. Figure 9 shows the process for beam configuration and activation of the PDSCH. The list of TCI states for the PDSCH may be indicated by a higher-layer catalog such as RRC (900). The list of TCI states may be indicated, for example, by tci-StatesToAddModList and / or tci-StatesToReleaseList in the BWP-specific PDSCH-Config IE. Next, some of the TCI states in the list may be activated by MAC-CE (940). The maximum number of TCI states to be activated may be determined by the capability reported by the terminal. 950 is an example of a MAC-CE structure for PDSCH TCI state activation / deactivation.

[0176] The meaning of each field in the MAC CE and the values ​​that can be set for each field are as follows:

[0177] - Serving Cell ID: This field indicates the identity of the Serving Cell for which the MAC CE applies. The length of the field is 5 bits. If the indicated Serving Cell is configured as part of a simultaneousTCI-UpdateList1 or simultaneousTCI-UpdateList2 as specified in TS 38.331 [5], this MAC CE applies to all the Serving Cells configured in the set simultaneousTCI-UpdateList1 or simultaneousTCI-UpdateList2, respectively;

[0178] - BWP ID (Bandwidth Part Identifier): This field indicates a DL BWP for which the MAC CE applies as the codepoint of the DCI bandwidth part indicator field as specified in TS 38.212 [9]. The length of the BWP ID field is 2 bits. This field is ignored if this MAC CE applies to a set of Serving Cells;

[0179] - T i(TCI state identifier): If there is a TCI state with TCI-StateId i as specified in TS 38.331 [5], this field indicates the activation / deactivation status of the TCI state with TCI-StateId i, otherwise MAC entity shall ignore the Ti field. The Ti field is set to 1 to indicate that the TCI state with TCI-StateId i shall be activated and mapped to the codepoint of the DCI Transmission Configuration Indication field, as specified in TS 38.214 [7]. The Ti field is set to 0 to indicate that the TCI state with TCI-StateId i shall be deactivated and is not mapped to the codepoint of the DCI Transmission Configuration Indication field. The codepoint to which the TCI State is mapped is determined by its ordinal position among all the TCI States with Ti field set to 1, i.e. the first TCI State with T ifield set to 1 shall be mapped to the codepoint value 0, second TCI State with Ti field set to 1 shall be mapped to the codepoint value 1 and so on. The maximum number of activated TCI states is 8;

[0180] - CORESET Pool ID (CORESET Pool ID identifier): This field indicates that mapping between the activated TCI states and the codepoint of the DCI Transmission Configuration Indication set by field Ti is specific to the ControlResourceSetId configured with CORESET Pool ID as specified in TS 38.331 [5]. This field set to 1 indicates that this MAC CE shall be applied for the DL transmission scheduled by CORESET with the CORESET pool ID equal to 1, otherwise, this MAC CE shall be applied for the DL transmission scheduled by CORESET pool ID equal to 0. If the coresetPoolIndex is not configured for any CORESET, MAC entity shall ignore the CORESET Pool ID field in this MAC CE when receiving the MAC CE. If the Serving Cell in the MAC CE is configured in a cell list that contains more than one Serving Cell, the CORESET Pool ID field shall be ignored when receiving the MAC CE.

[0181] Next, we will explain the PDSCH processing procedure time. When a base station schedules a terminal to transmit a PDSCH using DCI format 1_0, 1_1, or 1_2, the terminal may require PDSCH processing time to receive the PDSCH by applying the transmission method indicated by DCI (such as the modulation / demodulation and coding instruction index (MCS), demodulation reference signal-related information, time and frequency resource allocation information, etc.). NR has defined the PDSCH processing time taking this into consideration. The terminal's PDSCH processing time may follow equation 3 below.

[0182] T proc,1 = ( N1 + d 1,1 + d2)( 2048 + 144 ) κ2 -μ T c + T ext ... Formula 3

[0183] As stated in equation 3 above, T proc,1 In this, each variable may have the following meanings.

[0184] - N1: The number of symbols determined by the terminal processing capability (UE processing capability) 1 or 2 and the numerology μ, based on the terminal's capabilities. If the terminal processing capability is reported as 1 in the terminal capability report, it has the value in Table 16, and if it is reported as 2 and the ability to use terminal processing capability 2 is set by higher-layer signaling, it may have the value in Table 17. The numerology μ is the number of symbols determined by the T proc,1 Maximize μ PDCCH , μ PDSCH , μ UL It may correspond to the minimum value among them, μ PDCCH , μ PDSCH , μ UL These can be interpreted as the numerology of the PDCCH that scheduled the PDSCH, the numerology of the scheduled PDSCH, and the numerology of the uplink channel to which the HARQ-ACK is sent, respectively.

[0185]

Table 16

[0186]

Table 17

[0187] - κ: 64

[0188] - T ext : When the terminal uses the shared spectrum channel connection method, the terminal calculates T ext which can be applied to the PDSCH processing time. Otherwise, T ext is assumed to be 0.

[0189] - If l1 indicating the PDSCH DMRS position value is 12, N in Table 16 above 1,0 has a value of 14, and otherwise has a value of 13.

[0190] - For PDSCH mapping type A, if the last symbol of PDSCH is the i-th symbol in the slot where PDSCH is transmitted and i < 7, d 1,1 is 7 - i, and otherwise, d 1,1 is 0.

[0191] - d2: When PUCCH with a high priority index overlaps in time with PUCCH or PUSCH with a low priority index, d2 of PUCCH with a high priority index may be set to the value reported by the terminal. Otherwise, d2 is 0.

[0192] [[ID=四十八]] [[ID=四十九]] - When PDSCH mapping type B is used for terminal processing capability 1, d[[ID=五十]] 1,1The value may be determined by L, which is the number of symbols of the scheduled PDSCH, and d, which is the number of overlapping symbols between the PDCCH that schedules the PDSCH and the scheduled PDSCH.

[0193] - If L≧7, then d 1,1 = 0

[0194] - If L≧4 and L≦6, then d 1,1 = 7 - L.

[0195] - If L=3, then d 1,1 =min(d,1).

[0196] - If L=2, then d 1,1 = 3 + d.

[0197] - When PDSCH mapping type B is used for terminal processing capacity 2, d 1,1 The value may be determined by L, which is the number of symbols of the scheduled PDSCH, and d, which is the number of overlapping symbols between the PDCCH that schedules the PDSCH and the scheduled PDSCH.

[0198] - If L≧7, then d 1,1 = 0

[0199] - If L≧4 and L≦6, then d 1,1 = 7 - L.

[0200] - If L=2,

[0201] * If the scheduled PDCCH is located within a CORESET consisting of 3 symbols, and the CORESET and the scheduled PDSCH have the same start symbol, d 1,1 = 3.

[0202] *Otherwise, d 1,1 = d.

[0203] - For a terminal supporting capability 2 within a given serving cell, the PDSCH processing time due to terminal processing capability 2 is applicable when the terminal has enabled processingType2Enabled, which is a higher-layer signaling setting, for that cell.

[0204] If the position of the first uplink transmit symbol of the PUCCH containing HARQ-ACK information (this position may take into account K1-, which is defined as the time of HARQ-ACK transmission, the PUCCH resources used for HARQ-ACK transmission, and timing advance effects) is after the last symbol of the PDSCH, then T proc,1 The terminal must send a valid HARQ-ACK message unless it begins before the first uplink transmit symbol that occurs after a certain amount of time. That is, the terminal must send a PUCCH containing a HARQ-ACK only if there is sufficient PDSCH processing time. Otherwise, the terminal cannot provide the base station with valid HARQ-ACK information corresponding to the scheduled PDSCH. -proc,1 This can be used for both general and extended CP cases. If the PDSCH is configured with two PDSCH transmission positions in one slot, d 1,1 This is calculated based on the position of the first PDSCH transmission within that slot.

[0205] Next, we will explain the antenna port field indication included in DCI format 1_1 and DCI format 1_2. The antenna port field in DCI format 1_1 and 1_2 may be represented by 4, 5, or 6 bits and may be indicated by Tables 18 to 25 below. Table 18 shows the antenna port indication when Antenna port(s)(1000+DMRS port), dmrs-Type=1, and maxLength=1.

[0206] [Table 18]

[0207] Table 19 shows the antenna port designation when Antenna port(s)(1000+DMRS port), dmrs-Type=1, and maxLength=1.

[0208] [Table 19]

[0209] Table 20 shows the antenna port designation when Antenna port(s)(1000+DMRS port), dmrs-Type=1, and maxLength=2.

[0210] [Table 20]

[0211] Table 21 shows the antenna port designation when Antenna port(s)(1000+DMRS port), dmrs-Type=1, and maxLength=2.

[0212] [Table 21]

[0213] Table 22 shows the antenna port designation when Antenna port(s)(1000+DMRS port), dmrs-Type=2, and maxLength=1.

[0214] [Table 22]

[0215] Table 23 shows the antenna port designation when Antenna port(s)(1000+DMRS port), dmrs-Type=2, and maxLength=1.

[0216] [Table 23]

[0217] Table 24 shows the antenna port designation when Antenna port(s)(1000+DMRS port), dmrs-Type=2, and maxLength=2.

[0218] [Table 24-1] [Table 24-2]

[0219] Table 25 shows the antenna port designation when Antenna port(s)(1000+DMRS port), dmrs-Type=2, and maxLength=2.

[0220] [Table 25-1] [Table 25-2]

[0221] Tables 18 and 19 are used when dmrs-type is 1 and maxLength is 1; Tables 20 and 21 are used when dmrs-Type=1 and maxLength=2; Tables 22 and 23 indicate the DMRS port to use when dmrs-type=2 and maxLength=1; and Tables 24 and 25 indicate the DMRS port to use when dmrs-type is 2 and maxLength is 2.

[0222] If 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 directed to a DMRS port using Tables 19, 21, 23, and 25; otherwise, the terminal may be directed to a DMRS port using Tables 18, 20, 22, and 24. If a terminal is directed to a code point indicating two TCI states in the TCI state field, the terminal may be directed to entries in Tables 19, 21, 23, and 25 that indicate DMRS ports 1000, 1002, and 1003 for NC-JT scheduling purposes, which may be entries 12 in Table 19, 31 in Table 21, 24 in Table 23, and 58 in Table 25.

[0223] For DCI format 1_1, if the terminal is configured with both dmrs-DownlinkForPDSCH-MappingTypeA and dmrs-DownlinkForPDSCH-MappingTypeB, which are upper-layer signaling, the bit length of the Antenna port field in DCI format 1_1 is max{x -A ,x B It is determined to be}, where x A and x B These can be interpreted as the bit length of the Antenna port field determined by dmrs-DownlinkForPDSCH-MappingTypeA and dmrs-DownlinkForPDSCH-MappingTypeB, respectively. A and x B If the PDSCH mapping type corresponding to the smaller of the values ​​is scheduled, |x A -x B The MSB bits, which only represent the number of items, may be assigned and transmitted as 0 bits.

[0224] For DCI format 1_2, if the terminal does not configure the higher-layer signaling antennaPortsFieldPresenceDCI-1-2, the DCI format 1_2 does not need to have an Antenna port field. In this case, the length of the Antenna port field may be 0 bits, and the terminal can determine the DMRS port by assuming the 0th entry in Tables 18, 20, 22, and 24 above. If the terminal configures the higher-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 dmrs-DownlinkForPDSCH-MappingTypeA-DCI-1-2 and dmrs-DownlinkForPDSCH-MappingTypeB-DCI-1-2, which are upper layer signaling, the bit length of the Antenna port field in DCI format 1_2 will be max{x -A ,x B It is determined that}, where x A and x B These can be interpreted as the bit length of the Antenna port field determined by dmrs-DownlinkForPDSCH-MappingTypeA-DCI-1-2 and dmrs-DownlinkForPDSCH-MappingTypeB-DCI-1-2, respectively. If x A and x B If the PDSCH mapping type corresponding to the smaller of the values ​​is scheduled, |x A -x B The MSB bits, which only represent the number of items, may be assigned and transmitted as 0 bits.

[0225] In Tables 18 to 25, the numbers 1, 2, and 3 indicated by "Number of DMRS CDM group(s) without data" represent CDMR groups {0}, {0,1}, and {0,1,2}, respectively. DMRS port(s) are a sequential list of the port indices used. Antenna port is indicated by DMRS port + 1000. The DMRS CDM group is linked to the method of generating the DMRS sequence and the antenna port, as shown in Tables 26 and 27. Table 26 shows the parameters when using dmrs-type=1, and Table 27 shows the parameters when using dmrs-type=2.

[0226] [Table 26]

[0227] [Table 27]

[0228] The DMRS sequence for each parameter is determined as follows: p represents the DMRS port, k represents the subcarrier index, l represents the OFDM symbol index, μ represents the subcarrier interval, and w f (k' and w t (l') represents the FD-OCC (frequency domain orthogonal cover code) coefficient and TD-OCC (time domain orthogonal cover code) coefficient based on the k' and l' values, respectively, and Δ represents the spacing between CDM groups in terms of the number of subcarriers.

number

number

number

[0229]

number

[0230]

number

[0231] When DMRS type 1 is used, if a terminal is scheduled with a single codeword according to Tables 18 and 20 and instructed to enter entries 2, 9, 10, 11, and 30, or with a single codeword according to Table 19 and instructed to enter entries 2, 9, 10, 11, and 12, or with a single codeword according to Table 21 and instructed to enter entries 2, 9, 10, 11, 30, and 31, or if two codewords are scheduled, the terminal can be considered to be in single-user MIMO scheduling. That is, the terminal can assume that no other terminals are scheduled on any of the remaining orthogonal DMRS ports other than the DMRS port assigned to the scheduled PDSCH, and does not need to expect multi-user MIMO (MU-MIMO) scheduling. In such cases, the terminal does not need to perform multi-user MIMO receiving operations such as cancelling, nulling, or whitening, without assuming that other terminals are simultaneously scheduled (co-scheduled).

[0232] When DMRS type 2 is used, if a terminal is scheduled with a single codeword according to Tables 22 and 24 and directed to entries 2, 10, and 23, or with a single codeword according to Table 23 and directed to entries 2, 10, 23, and 24, or with a single codeword according to Table 25 and directed to entries 2, 10, 23, and 58, or if two codewords are scheduled, the terminal can be considered to be in single-user MIMO scheduling. That is, the terminal can assume that no other terminals are scheduled on any of the remaining orthogonal DMRS ports other than the DMRS port assigned to the scheduled PDSCH, and does not need to expect multiple-user MIMO scheduling. In such a case, the terminal does not need to assume that other terminals are co-scheduled and does not need to perform multiple-user MIMO receiving operations such as cancellation, nulling, or whitening of multiple-user interference.

[0233] The terminal does not need to expect that the maximum number of front-loaded DMRS symbols will be set to len2 by the upper-layer signaling maxLength, and that more than one additional DMRS symbol will be set by the upper-layer signaling dmrs-AdditionalPosition.

[0234] Terminals do not need to expect that the actual number of front-loaded DMRS symbols, the actual number of additional DMRS symbols, the DMRS symbol positions, and the DMRS type settings will differ for all terminals scheduled for multi-user MIMO.

[0235] For terminals with a PRG size of 2 or 4, it is not necessary to expect that frequency resource allocation will not match on the PRG unit grid for other terminals scheduled simultaneously using other orthogonal DMRS ports within the same CDM group as the DMRS port designated for that terminal.

[0236] For PDSCH scheduled in DCI format 1_1 and 1_2, a terminal may include DMRS ports assigned to other terminals that are simultaneously scheduled (co-scheduled) by the multi-user MIMO scheme, as indicated in the column "Number of DMRS CDM group(s) without data" in Tables 18 to 25 above, and it can be assumed that these ports do not need to be used for data transmission by the terminal. The values ​​1, 2, and 3 indicated in the column "Number of DMRS CDM group(s) without data" in Tables 18 to 25 can be understood as corresponding to the CDM group indices CDM groups 0, {0,1}, and {0,1,2}, respectively.

[0237] If a terminal is configured with the higher-layer signaling dmrs-FD-OCC-disableForRank1PDSCH and is assigned one DMRS port for PDSCH scheduling, the terminal does not need to expect that other orthogonal DMRS ports belonging to the same CDM group as the assigned DMRS port, which use other FD-OCCs, will be assigned to other terminals.

[0238] In LTE and NR, a terminal can perform a procedure to report its capability to a serving base station while connected to that base station. In the following description, this will be referred to as a terminal capability report (UE capability report).

[0239] A base station can transmit a UE capability enquiry message to a connected terminal requesting capability reporting. This message may include terminal capability requests for each RAT (radio access technology) type from the base station. These RAT type requests may include information on supported frequency band combinations. Furthermore, in the case of the terminal capability enquiry message, multiple RAT type UE capabilities may be requested within a single RRC message container transmitted by the base station, or the base station can transmit a terminal capability enquiry message containing each RAT type request multiple times. That is, the terminal capability enquiry may be repeated multiple times within a single message, and the terminal can construct and report corresponding UE capability information messages multiple times. Next-generation mobile communication systems can perform terminal capability enquiries for NR, LTE, EN-DC (E-UTRA-NR dual connectivity), and other MR-DC (Multi-RAT dual connectivity) technologies. While the terminal capability enquiry message is generally transmitted initially after a terminal connects to a base station, the base station can request it under any conditions when necessary.

[0240] In the aforementioned stage, a terminal that receives a UE capability report request from a base station configures its terminal capabilities according to the RAT type and band information requested by the base station. Next, the method by which a terminal configures its UE capability in an NR system is summarized.

[0241] 1. If a terminal receives a list of LTE and / or NR bands from a base station via UE capability request, the terminal configures band combinations (BCs) for EN-DC and NR stand alone (SA). That is, it configures a list of candidate BCs for EN-DC and NR SA based on the bands requested from the base station via FreqBandList. The priority of the bands is determined in the order listed in FreqBandList.

[0242] 2. If a base station requests a UE capability report by setting the "eutra-nr-only" flag or the "eutra" flag, the terminal will completely remove NR SA BCs from the candidate list of configured BCs as described above. This action may only occur if the LTE base station (eNB) requests "eutra" capability.

[0243] 3. Subsequently, the terminal removes the fallback BC from the candidate list of BCs configured in the previous step. Here, a fallback BC means a BC obtained by removing a band corresponding to at least one SCell from a particular BC, and this step is optional as the BC before removing the band corresponding to at least one SCell already covers the fallback BC. This step also applies to MR-DC, i.e., to LTE bands. The BCs remaining after this step constitute the final "candidate BC list".

[0244] 4. The terminal selects a BC that matches the requested RAT type from the final "Candidate BC List" and selects the BC to report. At this stage, the terminal configures the supportedBandCombinationList in a predetermined order. That is, the terminal configures the BCs and UE capabilities to report according to the pre-configured rat-Type order (nr->eutra-nr->eutra). It also configures a featureSetCombination for the configured supportedBandCombinationList and constructs a list of "Candidate Feature Set Combinations" in the Candidate BC List from which the list for fallback BCs (which include the same or lower level of capability) has been removed. This "Candidate Feature Set Combination" includes all feature set combinations for NR and EUTRA-NR BCs and can be obtained from the feature set combinations of the UE-NR-Capabilities and UE-MRDC-Capabilities containers.

[0245] 5. Also, if the requested rat Type is eutra-nr and has an impact, featureSetCombinations will be included in both the UE-MRDC-Capabilities and UE-NR-Capabilities containers. However, NR feature sets will only be included in UE-NR-Capabilities.

[0246] After the terminal capabilities are configured, the terminal transmits a terminal capabilities information message containing the terminal capabilities to the base station. Based on the terminal capabilities received from the terminal, the base station then performs appropriate scheduling and transmission / reception management for that terminal.

[0247] According to one embodiment of the present disclosure, a non-coherent joint transmission (NC-JT) may be used for a terminal to receive PDSCH from multiple TRPs.

[0248] Unlike existing systems, 5G wireless communication systems can support not only services requiring high transfer speeds, but also services with very short transmission delays and services requiring high connectivity density. In wireless communication networks including numerous cells, TRPs (transmission and reception points), or beams, coordinated transmission between each cell, TRP, or / and beam can meet various service requirements by increasing the signal strength received by the terminal or by efficiently controlling interference between each cell, TRP, or / and beam.

[0249] Joint Transmission (JT) is a representative transmission technique for the aforementioned cooperative communications, and it is a technique that increases the signal strength or processing rate received by a terminal by transmitting a signal to a single terminal via multiple different cells, TRPs, or / and beams. In this case, the characteristics of the channels between each cell, TRP, or / and beam and the terminal can differ significantly, and in particular, in the case of Non-Coherent Joint Transmission (NC-JT), which supports non-coherent precoding between each cell, TRP, or / and beam, individual precoding, MCS, resource allocation, TCI instructions, etc. may be required depending on the link-specific channel characteristics between each cell, TRP, or / and beam and the terminal.

[0250] The NC-JT transmission described above may be applied to at least one channel from the downlink data channel (PDSCH), downlink control channel (PDCCH), uplink data channel (PUSCH), and uplink control channel (PUCCH). When transmitting on the PDSCH, transmission information such as precoding, MCS, resource allocation, and TCI is indicated by DL DCI, and for NC-JT transmission, this transmission information needs to be indicated independently for each cell, TRP, and / or beam. This is a major factor that increases the payload required for DL ​​DCI transmission, which can adversely affect the receiving performance of the PDCCH transmitting the DCI. Therefore, for JT support on the PDSCH, it is necessary to carefully design the tradeoff between the amount of DCI information and the control information receiving performance.

[0251] Figure 10 shows an example of an antenna port configuration and resource allocation for transmitting a PDSCH using cooperative communication in a wireless communication system according to one embodiment of the present disclosure.

[0252] Referring to Figure 10, examples for PDSCH transmission are explained by joint transmission (JT) method, and examples for allocating radio resources by TRP are shown.

[0253] Referring to Figure 10, an example 1000 of a Coherent Joint Transmission (C-JT) supporting coherent precoding between each cell, TRP, or / or beam is shown.

[0254] In the case of C-JT, TRP A 1005 and TRP B 1010 can transmit single data (PDSCH) to terminal 1015, and joint precoding can be performed by multiple TRPs. This means that DMRS is transmitted on the same DMRS port for TRP A 1005 and TRP B 1010 to transmit the same PDSCH. For example, TRP A 1005 and TRP B 1010 can each transmit DRMS ​​to the terminal through DMRS port A and DMRS B, respectively. In this case, the terminal can receive one DCI information to receive one PDSCH demodulated based on the DMRS transmitted through DMRS port A and DMRS B.

[0255] Figure 10 shows an example of a Non-Coherent Joint Transmission (NC-JT) that supports non-coherent precoding between each cell, TRP, or / and beam for PDSCH transmission.

[0256] In the case of NC-JT, a PDSCH is transmitted to terminal 1035 for each cell, TRP, or / and beam, and individual precoding may be applied to each PDSCH. By having each cell, TRP, or / and beam transmit a different PDSCH or a different PDSCH layer to the terminal, the processing rate can be improved compared to the transmission of a single cell, TRP, or / and beam. Furthermore, by having each cell, TRP, or / and beam repeatedly transmit the same PDSCH to the terminal, the reliability can be improved compared to the transmission of a single cell, TRP, or / and beam. For the sake of explanation, below, cells, TRPs, or / and beams will be collectively referred to as TRPs.

[0257] In this case, various radio resource allocations may be considered, such as when the frequency and time resources used by multiple TRPs for PDSCH transmission are all the same (1040), when the frequency and time resources used by multiple TRPs do not overlap at all (1045), or when some of the frequency and time resources used by multiple TRPs overlap (1050).

[0258] To support NC-JT, various forms, structures, and relationships of DCIs may be considered in order to assign multiple PDSCHs to a single terminal simultaneously.

[0259] Figure 11 shows an example of the configuration of downlink control information (DCI) for NC-JT in a wireless communication system according to one embodiment of the present disclosure, in which each TRP transmits different PDSCHs or different PDSCH layers to the terminal.

[0260] Referring to Figure 11, case #1(1100) is an example where, in addition to the serving TRP (TRP#0) used when a single PDSCH is transmitted, (N-1) different PDSCHs are transmitted from (N-1) additional TRPs (TRP#1~TRP#(N-1)), and the control information for the PDSCHs transmitted from the (N-1) additional TRPs is transmitted independently of the control information for the PDSCHs transmitted from the serving TRP. That is, a terminal can obtain control information for PDSCHs transmitted from different TRPs (TRP#0~TRP#(N-1)) using independent DCIs (DCI#0~DCI#(N-1)). The formats between the independent DCIs may be the same or different, and the payloads between the DCIs may also be the same or different. While the aforementioned case #1 can fully guarantee the degree of freedom of control or assignment for each PDSCH, if each DCI transmits with different TRPs, differences in coverage between DCIs may occur, potentially degrading reception performance.

[0261] Case #2 (1105) illustrates a situation where, in addition to the serving TRP (TRP#0) used when a single PDSCH is transmitted, (N-1) different PDSCHs are transmitted from (N-1) additional TRPs (TRP#1 to TRP#(N-1)), and each of the (N-1) additional TRPs transmits control information (DCI) for the PDSCH, with each of these DCIs being subordinate to the control information for the PDSCH transmitted from the serving TRP.

[0262] For example, DCI#0, which is control information for a PDSCH transmitted from a serving TRP (TRP#0), includes all information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2. However, shortened DCI (hereinafter referred to as sDCI) (sDCI#0 to sDCI#(N-2)), which is control information for a PDSCH transmitted from a cooperating TRP (TRP#1 to TRP#(N-1)), may include only some of the information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2. Therefore, in the case of sDCI, which transmits control information for a PDSCH transmitted from a cooperating TRP, the payload is smaller than that of normal DCI (nDCI), which transmits PDSCH-related control information transmitted from a serving TRP, and thus it is possible to include reserved bits compared to nDCI.

[0263] In the aforementioned case #2, the degree of freedom for controlling or assigning each PDSCH may be limited by the content of the information elements included in sDCI. However, because sDCI has superior receiving performance compared to nDCI, the probability of differences in coverage between DCIs may be lower.

[0264] Case #3 (1110) illustrates a situation where, in addition to the serving TRP (TRP#0) used when a single PDSCH is transmitted, (N-1) different PDSCHs are transmitted from (N-1) additional TRPs (TRP#1 to TRP#(N-1)), and one control information is transmitted for the PDSCHs of the (N-1) additional TRPs, and this DCI is subordinate to the control information for the PDSCH transmitted from the serving TRP.

[0265] For example, DCI#0, which is control information for a PDSCH transmitted from a serving TRP (TRP#0), includes all information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2. However, in the case of control information for a PDSCH transmitted from a cooperating TRP (TRP#1 to TRP#(N-1)), it is possible to collect and transmit only some of the information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2 into a single "secondary" DCI (sDCI). For example, the sDCI may include at least one piece of information from among the cooperating TRP's frequency domain resource assignment, time domain resource assignment, and HARQ-related information such as MCS. For other information not included in sDCI, such as the BWP (bandwidth part) indicator or carrier indicator, the DCI (DCI#0, normal DCI, nDCI) of the serving TRP may be used.

[0266] In case #3 (1110), the degree of freedom for controlling or assigning each PDSCH may be limited by the content of the information elements included in the sDCI, but the receiving performance of the sDCI can be adjusted, and the complexity of DCI blind decoding at the terminal may be reduced compared to case #1 (1100) or case #2 (1105).

[0267] Case #4(1115) is an example of a situation where, in addition to the serving TRP (TRP#0) used when a single PDSCH is transmitted, (N-1) different PDSCHs are transmitted from (N-1) additional TRPs (TRP#1~TRP#(N-1)). The control information for the PDSCHs transmitted from the (N-1) additional TRPs is transmitted using the same DCI (Long DCI) as the control information for the PDSCHs transmitted from the serving TRP. In other words, the terminal can obtain the control information for the PDSCHs transmitted from the different TRPs (TRP#0~TRP#(N-1)) using a single DCI. In case #4(1115), the complexity of the terminal's DCI blind decoding does not increase, but the number of cooperating TRPs is limited by the long DCI payload limit, which may result in a lower degree of freedom in PDSCH control or allocation.

[0268] In the following description and examples, sDCI may refer to various auxiliary DCIs, such as shortened DCI, secondary DCI, or normal DCI (DCI format 1_0~1_1 above) containing PDSCH control information transmitted from a cooperating TRP, and unless otherwise specified, the description is similarly applicable to the various auxiliary DCIs described above.

[0269] In the following description and examples, the aforementioned cases #1 (1100), #2 (1105), and #3 (1110), in which one or more DCIs (PDCCHs) are used to support NC-JT, can be distinguished as multiple PDCCH-based NC-JT, and the aforementioned case #4 (1115), in which a single DCI (PDCCH) is used to support NC-JT, can be distinguished as single PDCCH-based NC-JT. In multiple PDCCH-based PDCCH transmissions, a distinction may be made between a CORESET in which the DCI of the serving TRP (TRP#0) is scheduled and a CORESET in which the DCI of cooperating TRPs (TRP#1 to TRP#(N-1)) is scheduled. Methods for distinguishing CORESETs include distinguishing them by CORESET-specific upper-layer indicators and distinguishing them by CORESET-specific beam settings. Furthermore, in single-PDCCH-based NC-JT, instead of a single DCI scheduling multiple PDSCHs, a single PDSCH with multiple layers is scheduled, and the aforementioned multiple layers may be transmitted from multiple TRPs. In this case, the connection relationship between a layer and the TRP that transmits that layer may be indicated by a TCI (Transmission Configuration Indicator) indication for the layer.

[0270] In the embodiments of this disclosure, "cooperative TRP" may be replaced with various terms such as "cooperative panel" or "cooperative beam" in actual application.

[0271] In the embodiments of this disclosure, "when NC-JT applies" can be interpreted in various ways depending on the situation, such as "when a terminal receives one or more PDSCHs simultaneously on one BWP," "when a terminal receives PDSCHs simultaneously on one BWP based on two or more TCI (Transmission Configuration Indicator) indications," or "when the PDSCHs received by the terminal are associated with one or more DMRS port groups," but for the sake of explanation, a single expression is used.

[0272] In the present invention, the wireless protocol structure for NC-JT may be used in various ways depending on the TRP deployment scenario. For example, if there is no or small backhaul delay between cooperating TRPs, a method using a MAC layer multiplexing-based structure (CA-like method) is possible. On the other hand, if the backhaul delay between cooperating TRPs is not negligible (for example, if more than 2ms is required for information exchange such as CSI, scheduling, and HARQ-ACK between cooperating TRPs), a method using a TRP-independent structure from the RLC layer to ensure delay-robust characteristics is possible (DC-like method).

[0273] A terminal supporting C-JT and / or NC-JT can receive C-JT and / or NC-JT-related parameters or setting values ​​from the higher-layer configuration and set the terminal's RRC parameters based on this. For higher-layer configuration, the terminal can utilize UE capability parameters, such as tci-StatePDSCH. Here, the UE capability parameter, such as tci-StatePDSCH, can define TCI states for the purpose of PDSCH transmission, and the number of TCI states may be set to 4, 8, 16, 32, 64, or 128 in FR1, and to 64 or 128 in FR2, with a maximum of 8 states being set from the set number, which can be indicated by 3 bits in the TCI field of the DCI via a MAC CE message. The maximum value of 128 refers to the value indicated by kmaxNumberConfiguredTCIstatesPerCC in the tci-StatePDSCH parameter included in the terminal's capability signaling. Thus, the entire configuration process, from upper layer configuration to MAC CE configuration, may be applied to beamforming instructions or beamforming modification instructions for at least one PDSCH in a single TRP.

[0274] As one embodiment of the present disclosure, a multi-DCI-based multi-TRP transmission method will be described. The multi-DCI-based multi-TRP transmission method can configure downlink control channels for NC-JT transmission based on Multi-PDCCH.

[0275] In NC-JT based on multiple PDCCHs, each TRP may have a separate CORESET or search space when transmitting the DCI for the PDSCH schedule of each TRP. The TRP-specific CORESET or search space can be configured as at least one of the following cases:

[0276] * CORESET-specific upper layer index setting: The CORESET setting information set by the upper layer may include an index value, and the set CORESET-specific index value may distinguish the TRP that sends PDCCH in that CORESET. That is, in a set of CORESETs with the same upper layer index value, it can be assumed that the same TRP sends PDCCH, or that PDCCHs that schedule PDSCHs of the same TRP are sent. The CORESET-specific index described above can be named as CORESETPoolIndex, and for CORESETs with the same CORESETPoolIndex value set, it can be assumed that PDCCH is sent from the same TRP. For CORESETs where the CORESETPoolIndex value is not set, it can be assumed that the base value of CORESETPoolIndex is set, and the base value described above may be 0.

[0277] ** In this disclosure, if each of the multiple CORESETs included in the upper-layer signaling PDCCH-Config has more than one type of CORESETPoolIndex, i.e., each CORESET has a different CORESETPoolIndex from one another, then the terminal may consider that the base station can use a multi-DCI-based multi-TRP transmission method.

[0278] **In contrast, in this disclosure, if each of the multiple CORESETs included in the upper-layer signaling PDCCH-Config has only one type of CORESETPoolIndex, that is, if all CORESETs have a CORESETPoolIndex such as 0 or 1, the terminal may assume that the base station is transmitting using single-TRP without using a multi-DCI-based multi-TRP transmission method.**

[0279] * Multiple PDCCH-Config settings: Multiple PDCCH-Configs may be configured in a single BWP, and each PDCCH-Config may include TRP-specific PDCCH settings. That is, one PDCCH-Config may contain a list of TRP-specific CORESETs and / or a list of TRP-specific search spaces, and one or more CORESETs and one or more search spaces included in one PDCCH-Config may be considered to correspond to a specific TRP.

[0280] * CORESET beam / beamgroup configuration: The TRPs corresponding to a CORESET may be distinguished by the beams or beamgroups configured for each CORESET. For example, if the same TCI state is set for multiple CORESETs, the CORESETs may be considered to transmit via the same TRP, or the PDCCHs that schedule PDSCHs for the same TRP may be considered to be transmitted for the CORESETs.

[0281] * Search Space Beam / Beam Group Configuration: Beams or beam groups may be configured for each search space, thereby distinguishing TRPs by search space. For example, if the same beam / beam group or TCI state is set in multiple search spaces, it may be considered that the same TRP transmits PDCCH in those search spaces, or that a PDCCH scheduling a PDSCH for the same TRP is transmitted in those search spaces.

[0282] As described above, by distinguishing the CORESET or search space by TRP, it is possible to classify PDSCH and HARQ-ACK information for each TRP, thereby enabling independent HARQ-ACK codebook generation and independent PUCCH resource usage for each TRP.

[0283] The settings described above may be independent for each cell or each BWP. For example, a PCell may have two different CORESETPoolIndex values ​​set, but a specific SCell may not have a CORESETPoolIndex value set. In this case, NC-JT transmission can be considered to have been configured for the PCell, but not for the SCell where the CORESETPoolIndex value was not set.

[0284] A PDSCH TCI state activation / deactivation MAC-CE applicable to a multi-DCI-based multi-TRP transmission method may be as shown in Figure 9. If a terminal has not set a CORESETPoolIndex for each of the CORESETs in the upper layer signaling PDCCH-Config, the terminal may ignore the CORESET Pool ID field 955 in the MAC-CE 950. If a terminal can support a multi-DCI-based multi-TRP transmission method, i.e., if each CORESET in the upper layer signaling PDCCH-Config has a different CORESETPoolIndex, the terminal can activate the TCI state in the DCI contained in the PDCCH transmitted by a CORESET having the same CORESETPoolIndex value as the CORESET Pool ID field 955 value in the MAC-CE 950. For example, if the CORESET Pool ID field 955 value in the MAC-CE 950 is 0, the TCI state in the DCI contained in the PDCCH sent from a CORESET whose CORESETPoolIndex is 0 may conform to the activation information of the MAC-CE.

[0285] When a terminal is configured to use the multi-DCI-based multi-TRP transmission method from the base station, that is, when each of the multiple CORESETs included in the upper-layer signaling PDCCH-Config has more than one type of CORESETPoolIndex, or when each CORESET has different CORESETPoolIndexes, the terminal will find that the following constraints exist for PDSCHs scheduled from PDCCHs within each CORESET that have two different CORESETPoolIndexes.

[0286] 1) A terminal can apply the TCI state indicated by each PDCCH to different CDM groups if the PDSCHs indicated by the PDCCHs within each CORESET, which have two different CORESETPoolIndexes, completely or partially overlap. In other words, it is not necessary for more than one TCI state to be applied to a single CDM group.

[0287] 2) The terminal can expect that the actual number of front-loaded DMRS symbols, the actual number of additional DMRS symbols, the actual positions of DMRS symbols, and the DMRS types of each PDSCH will not differ from each other, if the PDSCHs indicated by the PDCCHs within each CORESET, which have two different CORESETPoolIndexes, completely or partially overlap.

[0288] 3) The terminals can be expected to have identical bandwidth portions indicated by the PDCCH within each CORESET, each having two different CORESETPoolIndexes, and to have identical subcarrier intervals.

[0289] 4) The terminal can expect that information for scheduled PDSCHs from PDCCHs within each CORESET, which have two different CORESETPoolIndexes, is fully contained within each PDCCH.

[0290] As one embodiment of the present disclosure, a single-DCI-based multi-TRP transmission method is described. The single-DCI-based multi-TRP transmission method can configure a downlink control channel for NC-JT transmission based on a single-PDCCH.

[0291] In a single DCI-based multi-TRP transmission method, a single DCI can schedule a PDSCH transmitted by multiple TRPs. In this case, the number of TCI states may be used to indicate the number of TRPs transmitting the PDSCH. That is, if the number of TCI states indicated by the DCI scheduling the PDSCH is two, it can be considered a single PDCCH-based NC-JT transmission, and if the number of TCI states is one, it can be considered a single-TRP transmission. The TCI states indicated by the DCI may correspond to one or two TCI states activated by the MAC-CE. If the TCI states of the DCI correspond to two TCI states activated by the MAC-CE, then a correspondence relationship exists between the TCI codepoint indicated by the DCI and the TCI states activated by the MAC-CE, and there may be two TCI states activated by the MAC-CE that correspond to that TCI codepoint.

[0292] As yet another example, if at least one code point among all the code points in the TCI state field within the DCI indicates two TCI states, the terminal may assume that the base station can transmit based on a single-DCI-based multi-TRP method. In this case, at least one code point in the TCI state field indicating two TCI states may be activated by the Enhanced PDSCH TCI state activation / deactivation MAC-CE.

[0293] Figure 12 shows the structure of the Enhanced PDSCH TCI state activation / deactivation MAC-CE. The meaning of each field in the MAC-CE and the values ​​that can be set for each field are shown in Table 28.

[0294] [Table 28-1] [Table 28-2]

[0295] In Figure 12, if the value of field 1205 of C0 is 1, then the MAC-CE is the TCI state ID. 0,1 Field 1210 contains the TCI state ID 0,2 Field 1215 may be included further. This is the TCI state ID for the 0th code point of the TCI state field included in DCI. 0,1 and TCI state ID 0,2 This means that it is activated, and when the base station indicates the code point to the terminal, the terminal may be indicated two TCI states. If the value of the C0 field 1205 is 0, the MAC-CE is the TCI state ID 0,2 Field 1215 cannot be included, which is the TCI state ID for the 0th code point of the TCI state field included in DCI. 0,1 This means that one TCI state corresponding to that state is activated.

[0296] The above settings may be independent for each cell or BWP. For example, a PCell may have a maximum of two activated TCI states corresponding to one TCI codepoint, while a specific SCell may have a maximum of one activated TCI state corresponding to one TCI codepoint. In this case, NC-JT transmission can be considered configured for the PCell, but not for the aforementioned SCell.

[0297] Next, we will describe how to distinguish between single-DCI-based multi-TRP PDSCH iterative transmission methods. A terminal may be instructed by the base station to use different single-DCI-based multi-TRP PDSCH iterative transmission methods (e.g., TDM, FDM, SDM) based on the DCI field value and upper-layer signaling settings. Table 29 below shows how to distinguish between single and multiple TRP-based methods instructed to the terminal by the value of a specific DCI field and upper-layer signaling settings.

[0298] [Table 29]

[0299] In Table 29 above, each column can be explained as follows:

[0300] - Number of TCI states (2 columns): This refers to the number of TCI states indicated in the TCI state field within the DCI, which can be 1 or 2.

[0301] - Number of CDM groups (3 columns): This refers to the number of distinct CDM groups for the DMRS ports indicated in the Antenna port field within the DCI. This can be 1, 2, or 3.

[0302] - repetitionNumber setting and instruction conditions (4 columns): There may be three conditions depending on whether a repetitionNumber is set for all TDRA entries that can be specified in the Time Domain Resource Allocation field in DCI, and whether the actually specified TDRA entry has a repetitionNumber setting.

[0303] * Condition 1: At least one of all TDRA entries that can be specified in the Time Domain Resource Allocation field contains a setting for repetitionNumber, and the TDRA entry specified in the Time Domain Resource Allocation field in DCI contains a setting for repetitionNumber greater than 1.

[0304] * Condition 2: At least one of all TDRA entries that can be specified in the Time Domain Resource Allocation field includes a setting for repetitionNumber, and the TDRA entry specified in the Time Domain Resource Allocation field in DCI does not include a setting for repetitionNumber.

[0305] * Condition 3: If all TDRA entries that can be specified in the Time Domain Resource Allocation field do not contain a setting for repetitionNumber.

[0306] - repetitionScheme setting related (5 columns): Indicates whether or not the repetitionScheme, which is a higher-level signaling, is set. The repetitionScheme, which is a higher-level signaling, may be set to one of the following: "tdmSchemeA", "fdmSchemeA", or "fdmSchemeB".

[0307] - Transmission method instructed to the terminal (6 columns): This refers to the single or multiple TRP method instructed by each combination (1 column) shown in Table 29 above.

[0308] * Single-TRP: This means a single TRP-based PDSCH transmission. If the terminal has the pdsch-AggegationFactor configured in the upper-layer signaling PDSCH-config, the terminal may be scheduled to perform single-TRP-based PDSCH repetition transmissions the configured number of times. Otherwise, the terminal may be scheduled to perform a single-TRP-based PDSCH transmission.

[0309] * Single-TRP TDM scheme B: This refers to a single-TRP-based inter-slot time resource partitioning-based PDSCH repetition transmission. Due to the repetitionNumber-related Condition 1 described above, the terminal repeatedly transmits PDSCH on the time resource for a number of slots greater than 1 (repetitionNumber) set in the TDRA entry indicated in the Time Domain Resource Allocation field. At this time, the same start symbol and symbol length of the PDSCH indicated in the TDRA entry are applied to each of the repetitionNumber slots, and the same TCI state is applied to each PDSCH repetition transmission. This method is similar to the slot aggregation method in that it performs inter-slot PDSCH repetition transmission on the time resource, but differs from slot aggregation in that it can dynamically decide whether or not to instruct repetition transmission based on the Time Domain Resource Allocation field in the DCI.

[0310] * Multi-TRP SDM: This refers to a multi-TRP-based spatial resource partitioning PDSCH transmission scheme. This method receives data in separate layers from each TRP and is not a repetitive transmission scheme, but it can increase the reliability of PDSCH transmission by increasing the number of layers and lowering the coding rate. The terminal can receive PDSCH by applying two TCI states, as indicated in the TCI state field within the DCI, to each of the two CDM groups indicated by the base station.

[0311] * Multi-TRP FDM scheme A: This refers to a multiple TRP-based frequency resource division PDSCH transmission scheme, which has one PDSCH transmission location (occasion). Unlike multi-TRP SDM, it is not a repetitive transmission, but it is a method that can increase the amount of frequency resources and lower the coding rate, enabling highly reliable transmission. Multi-TRP FDM scheme A can be applied to non-overlapping frequency resources by applying two TCI states indicated in the TCI state field within the DCI. If the PRB bundling size is determined to be wideband, the terminal receives the first ceil(N / 2) RBs with the first TCI state applied, and the remaining floor(N / 2) RBs with the second TCI state applied, if the number of RBs indicated in the Frequency Domain Resource Allocation field is N. Here, ceil(.) and floor(.) are operators that mean rounding up and rounding down to the first decimal place. If the PRB bundling size is determined to be 2 or 4, even-numbered PRGs receive by applying the first TCI state, and odd-numbered PRGs receive by applying the second TCI state.

[0312] * Multi-TRP FDM scheme B: This refers to a multiplex TRP-based frequency resource division PDSCH iterative transmission scheme, which has two PDSCH transmission locations (occasions), and PDSCH can be repeatedly transmitted to each location. Similar to A, Multi-TRP FDM scheme B can be applied to non-overlapping frequency resources, with each being one of the two TCI states indicated in the TCI state field within the DCI. If the PRB bundling size is determined to be wideband, the terminal receives the first ceil(N / 2) RBs with the first TCI state applied, and the remaining floor(N / 2) RBs with the second TCI state applied, if the number of RBs indicated in the Frequency Domain Resource Allocation field is N. Here, ceil(.) and floor(.) are operators that mean rounding up and rounding down to the first decimal place. If the PRB bundling size is determined to be 2 or 4, even-numbered PRGs receive by applying the first TCI state, and odd-numbered PRGs receive by applying the second TCI state.

[0313] * Multi-TRP TDM scheme A: This refers to a PDSCH iterative transmission scheme within a time resource partitioning slot based on multiple TRPs. A terminal will have two PDSCH transmission locations (occasions) within one slot. The first reception location may be determined based on the PDSCH start symbol and symbol length indicated in the Time Domain Resource Allocation field in the DCI. The start symbol of the second reception location of the PDSCH may be the position obtained by applying a symbol offset of the upper layer signaling StartingSymbolOffsetK from the last symbol of the first transmission location, from which the transmission location can be determined by the indicated symbol length. If the upper layer signaling StartingSymbolOffsetK is not set, the symbol offset can be considered as 0.

[0314] * Multi-TRP TDM scheme B: This refers to a PDSCH repetition transmission scheme between time resource partitioning slots based on multiple TRPs. A terminal will have one PDSCH transmission location (occasion) per slot, and can receive repetition transmissions based on the same PDSCH start symbol and symbol length in a number of slots specified by the repetitionNumber in the Time Domain Resource Allocation field within the DCI. If the repetitionNumber is 2, the terminal can receive the PDSCH repetition transmissions in the first and second slots by applying the first and second TCI states, respectively. If the repetitionNumber is greater than 2, the terminal can use different TCI state application methods depending on which of the higher-layer signaling, tciMapping, is set to. If tciMapping is set to cyclicMapping, the first and second TCI states are applied to the first and second PDSCH transmission locations, respectively, and this TCI state application method is applied identically to the remaining PDSCH transmission locations. If tciMapping is set to sequentialMapping, the first TCI state is applied to the first and second PDSCH transmission locations, the second TCI state is applied to the third and fourth PDSCH transmission locations, and this same TCI state application method is applied to the remaining PDSCH transmission locations.

[0315] Next, we will explain the scheduling method using MC-DCI (Multi-cell scheduling DCI).

[0316] In this disclosure, one DCI may be a Single-DCI or a single DCI format, and multiple DCIs may be a Multi-DCI or a multiple DCI format. In this disclosure, one DCI may be a single PDCCH and / or transmitted and received through a single PDCCH, and multiple DCIs may be multiple PDCCHs and / or transmitted and received through multiple PDCCHs.

[0317] Generally, a terminal receives one DCI, and this DCI may contain scheduling information for one cell. For example, in the DCI format 0_0 / 0_1 / 0_2, one PUSCH can be scheduled for one uplink cell. Also, in the DCI format 1_0 / 1_1 / 1_2, one PDSCH can be scheduled for one downlink cell. Here, the cell to be scheduled may be indicated by the CIF (carrier indication field) in the DCI format.

[0318] However, with this method, if PDSCH or PUSCH is scheduled in each of multiple cells, multiple DCIs need to be sent and received. Therefore, a large DCI overhead can occur. To reduce DCI overhead, a single DCI can schedule PDSCH or PUSCH for each of multiple cells. For convenience, this can be called MC-DCI. In this disclosure, MC-DCI may be a single DCI that schedules PDSCH and / or PUSCH for each of multiple cells. In this case, the DCI format of MC-DCI may be DCI format 1_X or 1_3 in the case of PDSCH scheduling, and DCI format 0_X or 0_3 in the case of PUSCH scheduling.

[0319] Within a specific cell, a terminal can report to the base station, based on its terminal capabilities, the number of candidate cell sets that can be scheduled by MC-DCI. In this case, a cell set means a set containing multiple cells. For example, cell set 1 may contain cells 1, 2, 3, and 4, and cell set 2 may contain cells 5, 6, 7, and 8. A cell set may contain a maximum of four cells, and the cells contained in each cell set do not need to overlap. In this case, the number of candidate cell sets that a terminal can report based on its terminal capabilities may be one or two or more.

[0320] If a terminal reports that there is one candidate cell set that can be scheduled by MC-DCI within a particular cell, 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 a cell within that single cell set.

[0321] If a terminal reports that there are two or more candidate cell sets that can be scheduled by MC-DCI within a particular cell, the terminal can expect that a cell set indicator field exists in the MC-DCI, and the terminal may be instructed by the base station to specify one cell set index in that field. The terminal can receive scheduling information for one or more cells within one of multiple cell sets via MC-DCI. The following explanation assumes that the terminal reports one candidate cell set, but the case where there are two or more candidate cell sets does not need to be excluded.

[0322] The cells that can be scheduled by MC-DCI may be configured at a higher layer. For example, assume that MC-DCI can schedule cells 0, 1, 2, and 3 (simultaneously). When a terminal receives the MC-DCI, it can receive scheduling information for cells 0, 1, 2, and 3. In other words, the terminal can obtain scheduling information for cells 0, 1, 2, and 3 from MC-DCI. For example, it may be configured at a higher layer that MC-DCI can schedule cells 0, 1, 2, and 3. Here, the scheduling information may include time-domain resource allocation (TDRA) information and / or frequency-domain resource allocation (FDRA) information for which data channels (PDSCH for downlinks and PUSCH for uplinks) are transmitted and received in each cell. Therefore, the terminal can obtain scheduling information for each cell via MC-DCI and can transmit and receive data channels to and from each cell.

[0323] A base station may not be able to schedule all cells configured on a terminal under certain circumstances. It may be impossible to schedule at least some of the multiple cells configured on a terminal. For example, a base station may have configured four cells (e.g., cell 0, cell 1, cell 2, cell 3) to be scheduled on a terminal using MC-DCI, but some of these cells may be unavailable for scheduling due to, for example, being scheduled on another terminal, poor channel conditions, or other reasons. In this case, the base station must be able to indicate to the terminal which of the pre-configured cells scheduled using MC-DCI will be scheduled. That is, the base station must be able to indicate one or more cells (actually) that will be scheduled from among the multiple cells configured to be scheduled using MC-DCI.

[0324] This may be indicated based on one of the following two methods, or based on at least one combination of the following two methods.

[0325] As a first method, the terminal can obtain information from MC-DCI indicating the cells that are co-scheduled in the current MC-DCI from among the already configured cells (e.g., cell 0, cell 1, cell 2, cell 3). That is, of the multiple cells configured to be scheduled in MC-DCI, one or more cells that are (actually) scheduled simultaneously by MC-DCI may be identified based on that MC-DCI. More specifically, the base station can set up a table on the terminal that contains the cells that are scheduled simultaneously. For example, each row in this table may have a unique index. The index of each row (and / or each row) may contain the index of the cells that are scheduled simultaneously. For example, row 0 may contain {cell 0, cell 1}, row 1 may contain {cell 2, cell 3}, and row 2 may contain {cell 0, cell 1, cell 2, cell 3}. An example of a table set up on the terminal can be seen in Table 30.

[0326] [Table 30]

[0327] The terminal can obtain a value from MC-DCI indicating the index of the row. Therefore, the terminal can determine which cells are scheduled based on this value. For example, MC-DCI may include information about the row index, and the terminal can identify the scheduled cells based on the row index and table obtained from MC-DCI. For example, if row 0 is indicated from MC-DCI, the terminal can identify that cells 0 and 1 are scheduled cells. For example, if row 1 is indicated from MC-DCI, the terminal can identify that cells 2 and 3 are scheduled cells. For example, if row 2 is indicated from MC-DCI, the terminal can identify that cells 0, 1, 2, and 3 are scheduled cells.

[0328] In this disclosure, a table is set up for the mapping relationship between a scheduled cell (or the index of a scheduled cell) and an index indicated by DCI, and the scheduled cell may be identified based on the table and the index indicated by DCI.

[0329] While this disclosure describes an embodiment in which cells to be scheduled simultaneously are identified based on the index of a table row, the disclosure is not limited thereto. For example, cells to be scheduled may be identified based on the index of a table column, in which case rows may be replaced with columns in the above embodiment.

[0330] In this disclosure, if there are two or more candidate cell sets that can be scheduled by the MC-DCI received by the terminal within a particular cell, the terminal may set up a table like the one described above for each cell set, and the terminal can determine which table to use for which cell set by the cell set indicator field in the MC-DCI.

[0331] As a second method, the terminal can determine whether or not scheduling information exists for one or more cells based on the FDRA field of MC-DCI.

[0332] If the terminal reports that there is one candidate cell set that can be scheduled by MC-DCI within a particular cell, the terminal can expect that there are as many FDRA fields in MC-DCI as there are cells within that single cell set. In this case, if the terminal does not receive the same upper-layer signaling configuration as the table mentioned in the first method above, the terminal can determine whether scheduling information exists for each cell based on one or more FDRA fields in MC-DCI.

[0333] If a terminal reports the number of candidate cell sets that can be scheduled by MC-DCI within a particular cell using two or more terminal capabilities, the terminal can expect that there are FDRA fields corresponding to the maximum number of cells contained in each of the two or more cell sets. For example, if a terminal reports two candidate cell sets, with the first cell set containing three cells and the second cell set containing four cells, the terminal can expect that there are four FDRA fields in the MC-DCI, which is the maximum number of cells contained in the first and second cell sets, respectively.

[0334] - If the terminal is unable to receive the same upper-layer signaling settings for all cell sets as the table mentioned in the first method, the terminal can determine whether scheduling information exists for each cell based on the FDRA field in MC-DCI. If the number of cells in the cell set indicated by the cell set indicator field is less than the number in the FDRA field, the terminal can consider the FDRA field corresponding to the number of cells in the indicated cell set as an ascending index of the FDRA field, and ignore the FDRA field corresponding to an index greater than the number of cells.

[0335] - If the terminal has received the same upper-layer signaling settings as the table mentioned in the first method for a particular set of cells, but has not received them for the remaining sets of cells, the terminal can expect that the MC-DCI contains a scheduling cell indicator field that can indicate the index of a particular row in the table configured by the upper-layer signaling, as in the first method described above. When the terminal determines whether there is scheduling information for one or more cells that indicate which set of cells is indicated by the cell set indicator field in the MC-DCI, it can parse the scheduling cell indicator field or use a method of parsing 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 in the MC-DCI. If the terminal is indicated by the cell set indicator field in the MC-DCI for a set of cells that has received the same upper-layer signaling as the table, the terminal may be indicated by the scheduling cell indicator field for the presence or absence of scheduling information for one or more cells. If the terminal is indicated by the cell set indicator field in MC-DCI for a cell set for which the same upper-layer signaling as the table is not set, the terminal may be indicated by the FDRA field for the presence or absence of scheduling information for one or more cells.

[0336] Figure 13 shows an example of an MC-DCI according to one embodiment of the present disclosure that includes multiple FDRA fields.

[0337] Referring to Figure 13, the MC-DCI 1300 may include multiple FDRA fields. Each FDRA field may have a corresponding cell. That is, if the cells that can be simultaneously scheduled by the MC-DCI 1300 are set to be cell 0 1320, cell 1 1321, cell 2 1322, and cell 3 1323, then the MC-DCI 1300 may include FDRA field 1310 for cell 0, FDRA field 1311 for cell 1, FDRA field 1312 for cell 2, and FDRA field 1313 for cell 3. Based on the values ​​of the FDRA fields, it may be determined whether or not each cell is scheduled. Cells that are scheduled based on the values ​​of the FDRA fields can be called actually co-scheduled cells.

[0338] Figure 14 shows 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.

[0339] Referring to Figure 14, the MC-DCI 1400 may include a cell set indicator field 1401, a scheduling cell indicator field 1402, and at least one of several FDRA fields 1405, 1406, 1407, and 1408. As described above, if a terminal receives an MC-DCI in a particular cell and reports to the base station that there are two or more candidate cell sets that can be scheduled, the terminal can expect that the cell set indicator field 1401 is present in the MC-DCI, and if it reports one to the base station, the field does not need to be present. Figure 14 shows the case where the terminal reports two candidate cell sets. Cell set 0 1410 contains three cells: cell 0 1411, cell 1 1412, and cell 2 1413. Cell set 1 1420 may contain cells 3 1421, cell 4 1422, cell 5 1423, and cell 6 1424. Therefore, the terminal can expect that 4 FDRA fields, representing the maximum number of cells included in cell set 0 1410 and cell set 1 1420 respectively, exist within MC-DCI.

[0340] Furthermore, Figure 14 assumes a situation where the terminal has not configured higher-layer signaling for cell set 0 1410, as shown in the table above. Therefore, as in the second method described above, the presence or absence of scheduling information for cells within cell set 0 1410 may be indicated by FDRA fields 1405, 1406, 1407, and 1408 in MC-DCI. In this case, since there are three cells in cell set 0 1410, the terminal may be instructed to provide scheduling information for cells 0 1411, 1 1412, and 21413 by the first, second, and third FDRA fields 1408, 1407, and 1406.

[0341] Furthermore, in Figure 14, it can be assumed that the terminal has configured higher-layer signaling, such as the table described above, for the cell set 11420. Therefore, as in the first method described above, the presence or absence of scheduling information for cells within the cell set 11420 may be indicated by the scheduling cell indicator field 1402 in MC-DCI. For example, the terminal may indicate a specific row from all the rows in the table configured by the higher-layer signaling using the scheduling cell indicator field 1402 in MC-DCI, and that row can indicate scheduling information for cells 3 1421 and 5 1423 within the cell set 1 1420, for example.

[0342] The FDRA field may be distinguished into valid and invalid values. A valid value is one in which a frequency domain assignment corresponding to the value of the FDRA field exists. Conversely, an invalid value is one in which no frequency domain assignment corresponding to the value of the FDRA field exists.

[0343] For example, let's explain valid and invalid values ​​based on FDRA type-0. FDRA type-0 is a way of indicating which RB (or RBG) is scheduled based on a bitmap. Here, each bit may contain a corresponding RB (or RBG). If a bit is "1", the corresponding RB (or RBG) is scheduled; if a bit is "0", the corresponding RB (or RBG) does not need to be scheduled. Therefore, if at least one bit is "1", it can be determined to be a valid value, and if all bits are "0", it can be determined to be an invalid value.

[0344] For example, let's explain valid and invalid values ​​based on FDRA type-1. FDRA type-1 is a method for specifying RBs scheduled based on RIV (resource indication value). Here, FDRA type-1 can schedule consecutive RBs in the frequency domain. FDRA type-1 can specify 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 to be a valid value, and if it is equal to or greater than N*(N+1) / 2, it can be determined to be an invalid value.

[0345] Some of the cells scheduled by MC-DCI may be in the licensed band, while others may be in the unlicensed band (or shared spectrum). For example, in the case of unlicensed band cells, FDRA type-2 will need to be used during uplink scheduling. Specific information on FDRA type-2 or an example of its use will be described later.

[0346] This disclosure discloses a method for determining which cells are scheduled from a single DCI when a terminal supports multi-cell scheduling in a single DCI.

[0347] A terminal can receive multiple frequency domain resource assignment (FDRA) fields in a single DCI and determine the cell corresponding to each FDRA field. The terminal can determine whether or not a cell is scheduled using the cell's FDRA type and the value of its FDRA field. The terminal can identify whether or not a cell is scheduled and / or whether a cell is scheduled and / or not, based on one or more of the FDRA type or FDRA fields. For example, the method of analyzing the FDRA field may differ depending on the subcarrier interval of the corresponding cell.

[0348] When a terminal is configured with FDRA type-2 in a single cell, whether or not to schedule the cell may be determined based on at least one or a combination of the following:

[0349] If the aforementioned cell has a 15kHz subcarrier interval, the terminal can determine that the cell was not scheduled if the value of the FDRA field is as follows:

[0350] In the first case, all bits in the FDRA field are "1".

[0351] In the second case, the first six bits of the FDRA field are all "1". That is, the 6 MSB (most significant bit) of the FDRA field is all "1".

[0352] In the third case, all Y bits at the end of the FDRA field are "1". That is, all Y LSBs (least significant bits) of the FDRA field are "1".

[0353] If the aforementioned cell has a 30kHz subcarrier interval, the terminal can determine that the cell was not scheduled if the value of the FDRA field is as follows:

[0354] In the first case, the first five bits of the FDRA field are all "0" and the last Y bits are all "1". That is, in the FDRA field, the five MSBs are all "0" and the Y LSBs are all "1".

[0355] The second case is when all bits in the FDRA field are "0".

[0356] The third case is when the first five bits of the FDRA field are all "0". That is, when all five MSB bits of the FDRA field are "0".

[0357] The fourth case is when all of the last Y bits in the FDRA field are "1". That is, when all of the Y LSB bits in the FDRA field are "1".

[0358] The following provides a detailed explanation for each situation.

[0359] Situation 1. When one cell has a 15kHz subcarrier interval.

[0360] The terminal can check information regarding the subcarrier interval 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 interval of that cell is 15kHz (μ=0) or 30kHz (μ=1). In this embodiment, the terminal may check that the subcarrier interval of the cell is 15kHz (μ=0).

[0361] Figure 15 shows an example of a field indicating frequency domain resource allocation information based on the subcarrier interval of a cell according to one embodiment of the present disclosure.

[0362] Referring to Figure 15(a), if the subcarrier interval of the cell is 15 kHz, the length of the field indicating the frequency domain allocation information of the cell in MC-DCI may be 6 + Y bits. Here, the 6 bits can indicate the start index (m0) and length (L) of M = 10 interlaces contained within one RB-set, and the Y bits indicate the scheduled RB set.

number

number

[0363] More specifically, the 6 bits are as follows: Referring to the RIV formula above or Table 13, the RIV values ​​0, 1, ..., M*(M+1) / 2-1=54 may indicate the starting interlace index and the number of consecutive interlace indices according to the RIV formula, and then RIV=M*(M+1) / 2=55, M*(M+1) / 2+1=56, ..., M*(M+1) / 2+7=62 may indicate the starting interlace index (m0) and the l value according to Table 13. The 6 bits of the RIV value can represent one of the values ​​0, 1, ..., 63, where 0, 1, ..., 62 are the values ​​used to schedule the interlace. However, RIV=63 (where the 6 bits in binary are "111111") may be an unused value. In other words, there may be no scheduled interlace corresponding to the aforementioned value (RIV=63). Therefore, the aforementioned value (RIV=63 (6 bits in binary "111111")) may be used to indicate an unscheduled cell.

[0364] More specifically, the Y bit is as follows. Referring to the description of the least significant bit (LSB) Y of the FDRA field for the 15kHz and 30kHz mentioned above, the following can be observed.

[0365] - If one RB set is included in UL BWP

number

[0366] - If 2 RB sets are included in UL BWP

number

[0367] - If 3 RB sets are included in UL BWP

number

[0368] - If 4 RB sets are included in UL BWP

number

[0369] - If 5 RB sets are included in UL BWP

number

[0370] In short, for all cases of the Y bit size except when Y=0, an unscheduled cell may be indicated if all Y bits are "1". That is, if all bits in the Y LSB of the FDRA are "1", an unscheduled cell may be indicated.

[0371] In this disclosure, the method by which a cell having a 15 kHz subcarrier interval is indicated not to be scheduled may be one or at least one combination of the following. In the description of this method, the FDRA field is the field corresponding to the cell having the 15 kHz subcarrier interval, and the FDRA type may be FDRA type-2.

[0372] - In the first method, the terminal can determine whether a 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 feed may include a 6-bit MSB and a Y-bit LSB. Therefore, the terminal can determine that a cell with a 15kHz subcarrier interval corresponding to the FDRA field is not scheduled if all of the total 6+Y bits are "1" (i.e., the bit values ​​of all bits included in the 6+Y bits are 1). For example, if all 6-bit MSBs are "1" and the remaining Y-bit LSBs are not "1" (i.e., the bit values ​​of all bits included in the 6MSBs are 1 and at least some of the bit values ​​of the bits included in the Y LSBs are 0, or the bit values ​​of all bits included in the 6MSBs are 1 and the bit values ​​of all bits included in the Y LSBs are 0), the terminal can determine that the DCI format containing the information is an error case. Alternatively, if all Y bits in the LSB are "1" and none of the remaining 6 bits in the MSB are "1" (i.e., all bits in the Y LSB have a value of 1 and at least some bits in the 6 MSB have a value of 0, or all bits in the Y LSB have a value of 1 and all bits in the 6 MSB have a value of 0), the terminal can determine that the DCI format containing the information is an error case. If the terminal determines it is an error case, it can discard (or ignore) the information indicated by the DCI format without applying it. If the terminal determines it is an error case, it can discard the information indicated by the DCI format for the cell (the cell corresponding to the FDRA field determined to be an error case) without applying it, and can apply the information for the remaining cells (the remaining cells other than the cell corresponding to the FDRA field determined to be an error case).

[0373] - In the second method, the terminal can determine whether a cell is scheduled based only on the 6-bit MSB of the FDRA field. The terminal can identify whether a cell is scheduled by the 6-bit 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 6MSB 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 15kHz subcarrier interval cell corresponding to the FDRA field is not scheduled if all bits of the total 6-bit MSB are "1". For example, in this case, the Y-bit LSB bit does not need to provide any information. That is, the presence or absence of cell scheduling can be determined based on the 6-bit MSB regardless of the value of the Y-bit LSB. For example, the Y-bit LSB may be discarded, ignored, or not included in the FDRA field (for example, Y=0).

[0374] - In the third method, the terminal can determine whether a cell is scheduled based solely on the Y-bit LSB of the FDRA field. The terminal can identify whether a cell is scheduled by the Y-LSB of the FDRA field. For example, if all bits of the Y-bit 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 15kHz subcarrier interval cell corresponding to the FDRA field is not scheduled if all bits of the total Y-bit LSB are "1". For example, in this case, the bits of the 6-bit MSB do not need to provide information. That is, the presence or absence of cell scheduling can be determined based on the Y-bit LSB regardless of the value of the 6-bit MSB. For example, the 6-bit MSB does not need to be discarded, ignored, or included in the FDRA field.

[0375] 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 to third methods may be selectively used based on the value of Y. In other words, the method used by the terminal may be determined based on the value of Y (the bit size of the Y LSB in the FDRA field).

[0376] Situation 2. When one cell has a 30kHz subcarrier interval.

[0377] The terminal can check information regarding the subcarrier interval 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 interval of that cell is 15kHz (μ=0) or 30kHz (μ=1). In this embodiment, the terminal may check that the subcarrier interval of the cell is 30kHz (μ=1).

[0378] Referring to Figure 15(b), if the subcarrier interval of the cell is 30 kHz, the length of the field indicating the frequency domain allocation information of the cell in MC-DCI may be 5 + Y bits. Here, the 5 bits can indicate in a bitmap whether or not M = 5 interlaces contained within one RB set are scheduled. That is, each of the 5 bits may be used to indicate whether or not one interlace is scheduled. Here, among the 5 bits, the interlace corresponding to the bit with a value of "1" may be determined to be scheduled. Among the 5 bits, the interlace corresponding to the bit with a value of "0" may be determined not to be scheduled. The Y bit indicates the scheduled RB set,

number

number

[0379] The aforementioned five bits can indicate interlacing to be scheduled on a bitmap basis. The terminal can determine that if each of the five bits is "1", the interlacing corresponding to "1" will be scheduled. That is, the interlacing corresponding to the bit with a value of "1" among the five bits may be determined to be scheduled. If all five bits are "0", there may be no interlacing to be scheduled. Therefore, if all five bits are "0", this can be used to determine that the cell will not be scheduled.

[0380] The Y bit in Situation 2 is the same as in Example 1 described above, so its explanation is omitted. For details, please refer to the explanation regarding the Y bit in Situation 1.

[0381] The FDRA field of a cell with a 30kHz subcarrier interval contains 5+Y bits, where the 5-bit MSB indicates the interlace scheduled within the RB set in a bitmap manner, and the Y-bit LSB indicates the scheduled RB set in a RIV manner. Therefore, the presence or absence of scheduling in a cell can be determined by the values ​​of the 5-bit MSB and the Y-bit LSB.

[0382] In this disclosure, the method for indicating that a cell having a 30 kHz subcarrier interval is not scheduled may be one or a combination of the following. In the description of this method, the FDRA field is the field corresponding to the cell having the 30 kHz subcarrier interval, and the FDRA type may be FDRA type-2.

[0383] - In the first method, the terminal can determine whether a cell is scheduled based on all bits (5+Y bits) of the FDRA field. For example, if all bits of the FDRA field are "0", the terminal can determine that the cell with the 30kHz subcarrier interval is not a scheduled cell. Here, the FDRA field may include 5 bits MSB and Y bits LSB. Therefore, based on the total of 5+Y bits, the terminal can determine that if all are "0" (if the bit values ​​of all bits included in the 5+Y bits are 0), the cell with the 30kHz subcarrier interval corresponding to the FDRA field is not scheduled. For example, if all Y bits LSB are "0", then RIV RB-set The formula may have corresponding values. However, if all 5 bits of the MSB are "0", the RB set indicated by the Y bit LSB does not need to be used as information regarding the presence or absence of scheduling. In other words, since all 5 bits of the MSB are "0", it is determined that there is no scheduled interlacing, so the RB set corresponding to the Y bit LSB can be ignored.

[0384] - In the second method, the terminal can determine whether or not a cell is scheduled based on the initial 5-bit MSB of the FDRA field. The terminal can identify whether or not a cell is scheduled through the 5-bit MSB of the FDRA field. For example, if all bits of the 5-bit MSB of the FDRA field are "0" (if the bit value of all bits included in the 5-bit 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 30kHz subcarrier interval cell corresponding to the FDRA field is not scheduled if all of the total 5-bit MSB are "0". For example, in this case, the Y-bit LSB bit does not need to provide any information. That is, the presence or absence of cell scheduling can be determined based on the 5-bit MSB regardless of the value of the Y-bit LSB. For example, the Y-bit LSB may be discarded, ignored, or not included in the FDRA field (for example, Y=0).

[0385] - In the third method, the terminal can determine whether a cell is scheduled based solely on the Y-bit LSB of the FDRA field. The terminal can identify whether a cell is scheduled by the Y-LSB of the FDRA field. For example, if all bits of the Y-bit 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 30kHz subcarrier interval cell corresponding to the FDRA field is not scheduled if all bits of the total Y-bit LSB are "1". For example, in this case, the bits of the 5-bit MSB do not need to provide information. That is, the presence or absence of cell scheduling can be determined based on the Y-bit LSB regardless of the value of the 5-bit MSB. For example, the 5-bit MSB may be discarded, ignored, or not included in the FDRA field.

[0386] 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 or third method may be selectively used based on the value of Y. That is, the method used by the terminal may be determined based on the value of Y (the bit size of the Y LSB in the FDRA field).

[0387] In this disclosure, determining the priority between A and B can 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.

[0388] In the following disclosure, the above examples will be described using multiple embodiments, which are not independent of each other, and one or more embodiments can be applied simultaneously or in combination.

[0389] In describing this disclosure below, higher-layer signaling may refer to at least one or a combination of the following signalings.

[0390] - MIB(Master Information Block)

[0391] - SIB (System Information Block) or SIB X (X=1,2,…)

[0392] - RRC (Radio Resource Control)

[0393] - MAC(Medium Access Control)CE(Control Element)

[0394] Furthermore, L1 signaling may be a signaling method that uses at least one or a combination of the following physical layer channels or signaling methods.

[0395] - PDCCH(Physical Downlink Control Channel)

[0396] - DCI(Downlink Control Information)

[0397] - UE-specific DCI

[0398] - Group common DCI

[0399] - Common DCI

[0400] - Scheduling DCI (e.g., DCI used for scheduling downlink or uplink data)

[0401] - Non-scheduling DCI (e.g., DCI not intended to schedule downlink or uplink data)

[0402] - PUCCH(Physical Uplink Control Channel)

[0403] - UCI(Uplink Control Information)

[0404] Hereafter, the term "slot" as used in this disclosure is a general term that can mean a specific time unit corresponding to TTI, and specifically may mean a slot used in a 5G NR system, or a slot or subframe used in a 4G LTE system.

[0405] <First Embodiment: Multi-User Scheduling Support Signaling>

[0406] As one embodiment of this disclosure, a multiple user scheduling support signaling that a terminal can receive from a base station is described. This embodiment may be operated in combination with other embodiments.

[0407] A base station can use a multiple-user MIMO scheduling method (hereinafter also referred to as MU-MIMO (Multi-User MIMO) scheduling) that allows multiple terminals to be scheduled to the same time and frequency resources as each other, which is a way to increase the overall system yield under limited time and frequency resources. With such a scheduling method, a given terminal may be scheduled to the same time and frequency resources as multiple other terminals when MU-MIMO scheduling is performed by the base station. As a result, the terminal may receive signals that are also being sent to other terminals, which can increase the amount of interference. Therefore, interference control at the base station and terminals may be important when MU-MIMO scheduling is performed. For interference control on the terminal side, a terminal may be equipped with a special receiver such as R-ML (Reduced complexity Maximum Likelihood). A terminal equipped with an R-ML receiver can identify all received signals intended for other terminals that are MU-MIMO scheduled together with the terminal, thereby increasing the accuracy of the signals that the terminal should receive.

[0408]

number

[0409] Equation 4 above shows that when N terminals are scheduled for downlink MU-MIMO from a base station, the received signal y of the i-th terminal is calculated. i This is a mathematical formula that expresses the following: i, which represents the index of the terminal, can be anywhere from 1 to N. Here, h i This is the channel between the base station and the i-th terminal, w iis the precoder at the base station for the i-th terminal, x i is the demodulated symbol transmitted to the i-th terminal, n i can represent the white noise received by the i-th terminal. Also, H k = h i w k may be the distorted channel where the precoder for the k-th terminal is multiplied by the channel of the i-th terminal. When i and k are the same (i.e., H k = h i w k ), the terminal can estimate H i using the assigned DMRS sequence and DMRS port information, and thereby decode the received signal. At this time, when the terminal can use the R-ML receiver, the terminal can detect the demodulated signals for the terminal itself and other terminals that satisfy the following Equation 5

Equation

[0410]

Equation

[0411] The above Equation 5 represents the principle of the R-ML receiver. The principle of the R-ML receiver is that for the i-th terminal, the difference between the received signal of the i-th terminal and the signal transmitted by the base station to the i-th terminal (constituted by the product of the distorted channel H k and the demodulated signal x k for all k-th terminals, where the channel between the base station and the i-th terminal is multiplied by the precoder for the k-th terminal) is minimized for the demodulated signals for the terminal itself and other terminals

Equation

number

number

number

[0412] The received signal y in equation 4 above i As can be seen, the i-th terminal is

number

[0413] Therefore, if the i-th terminal is scheduled in MU-MIMO with another terminal, and if that i-th terminal can use an R-ML receiver and knows at least the DMRS sequence and demodulation scheme of the other MU-MIMO scheduled terminal, the terminal can perform signal detection with appropriate complexity even when using an R-ML receiver.

[0414] For this purpose, the terminal can receive additional information related to MU-MIMO scheduling from the base station via DCI. This field may be named, for example, the MU-MIMO assist signaling field, may be 3 bits in size, and may define eight code points as shown in Table 32 below. The contents corresponding to each code point in Table 32 below are merely examples.

[0415] [Table 31]

[0416] As described above, when a terminal detects inter-terminal interference based on an R-ML receiver during MU-MIMO scheduling and attempts to improve detection performance for the signal the terminal is trying to receive, information on the DMRS sequence and demodulation method can be useful. Each of the eight code points in Table 32 above indicates the extent to which the R-ML receiver used by the terminal needs information when the base station schedules MU-MIMO including that terminal.

[0417] - An index (code point) of 0 in the MU-MIMO assist signaling field may mean that there are no other terminals scheduled with the terminal in MU-MIMO that have the same DMRS sequence as the terminal in question, and this may include the case of SU-MIMO scheduling instead of MU-MIMO scheduling. Hereinafter, a DMRS sequence may be understood as a DMRS sequence where r(n) is the same as described above, but is not limited to this. That is, if a terminal receives an index of 0 in the MU-MIMO assist signaling field from DCI, it can be assumed that it is not MU-MIMO scheduling (i.e., SU-MIMO scheduling, single-user MIMO scheduling, or there are no other terminals scheduled together for the same time and frequency resources), or even if it is MU-MIMO scheduling, there are no other terminals using the same DMRS sequence as the terminal in question.

[0418] * If the field indicates index 0, it can be interpreted that the terminal does not need to use an R-ML receiver when receiving signals transmitted from the base station.

[0419] - The indices (code points) 1 to 5 of the MU-MMO assist signaling field may mean that terminals scheduled for MU-MIMO with the terminal in question use the same DMRS sequence on all RBs assigned to that terminal, and use QPSK, 16QAM, 64QAM, 256QAM, or 1024QAM, respectively, as the demodulation scheme for the PDSCH. In other words, the indices (code points) 1 to 5 of the MU-MMO assist signaling field can inform the terminal of information regarding the DMRS sequence and demodulation scheme of other terminals that were necessary to use the R-ML receiver. In the case of the DMRS sequence, instead of informing the other terminals of their DMRS sequences themselves, by instructing the terminal to use the same DMRS sequence as the terminal in question, the terminal can reduce the complexity of channel estimation by reusing the DMRS sequence used by the terminal when attempting to estimate channel information for other terminals on a port other than the DMRS port scheduled for that terminal. In the case of the demodulation scheme, it can be assumed that all other terminals use the same specific demodulation scheme.

[0420] * If a terminal receives indices 1-5, the terminal will know the DMRS sequence information of other terminals scheduled for MU-MIMO with it. In the case of DMRS channel information required by equation 5 above, the terminal can use the DMRS sequence to estimate the channel for DMRS ports that were not scheduled for it. In this case, the demodulation scheme of the terminal may be the same as that of the other terminals. For example, if a specific terminal receives index 1 for the MU-MIMO assist signaling field, the demodulation scheme of that terminal and the other terminals scheduled for MU-MIMO with it can be considered to be QPSK. In contrast, there is no constraint that the demodulation scheme of the terminal must be the same as or different from that of the other terminals. For example, if a specific terminal receives index 1 for the MU-MIMO assist signaling field, the demodulation scheme of the other terminals scheduled for MU-MIMO with it can be considered to be QPSK, but there is no constraint that the demodulation scheme of the terminal must be QPSK or must not be QPSK.

[0421] - Index (code point) 6 of the MU-MIMO assist signaling field may represent a case that does not include indices 0 to 5. When index 6 is indicated in this field, if there are other MU-MIMO scheduled terminals, the terminal can expect that all other MU-MIMO scheduled terminals (which may be RBs, RBGs, or PRGs) will use a single, identical demodulation scheme and the same DMRS sequence as the terminal. In this case, it is not necessary to specify which particular demodulation scheme each of the other MU-MIMO scheduled terminals uses.

[0422] - Index (code point) 7 in the MU-MIMO assist signaling field may represent a case that does not include indices 0 to 6. If a terminal is indicated with index 7 in this field, and there is a MU-MIMO scheduled terminal, there may be no constraint on whether other terminals scheduled with that terminal use the same DMRS sequence as that terminal, or whether all other terminals use the same demodulation scheme. Therefore, if a terminal attempts to control interference with all other MU-MIMO scheduled terminals using an R-ML receiver and detect its desired signal, it may be possible to apply a blind method to the DMRS sequences and demodulation schemes of the other terminals scheduled with it. That is, the terminal can attempt to detect its desired signal under various assumptions about the DMRS sequences and demodulation schemes of the other terminals scheduled with it.

[0423] A terminal can report to a base station its terminal capability, which means that it can use an R-ML receiver and that it can receive the MU-MIMO assist signaling field from the base station. This terminal capability may be defined by at least one of the following criteria:

[0424] - The terminal can report to the base station that it can support all indices (code points) of the MU-MIMO assist signaling field with a single terminal capability.

[0425] - The terminals can indicate whether or not each index in the MU-MIMO assist signaling field is supported by different terminal capabilities.

[0426] * A terminal can individually report to the base station its terminal capability, for example, terminal capability that means supporting indices 1-5, terminal capability that means supporting indices 1-5 and up to index 6, and terminal capability that means supporting indices 1-6 and up to index 7.

[0427] * If a terminal reports terminal capability that means it supports indices 1-5, or terminal capability that means it supports indices 1-5 and up to index 6, or terminal capability that means it supports indices 1-6 and up to index 7, but the terminal does not report terminal capability that supports PDSCH 256QAM or terminal capability that supports PDSCH 1024QAM, the terminal does not expect the base station to instruct it to use index 4 or 5, or if the terminal is instructed to use index 4 or 5, it may consider it a reserved code point or ignore it. Also, if the terminal is instructed to use index 6 by the base station, the terminal may expect all other terminals scheduled for MU-MIMO for each scheduled RB (or RBG, PRG) to use a single identical demodulation scheme, in which case 256QAM or 1024QAM may be excluded from the possible demodulation schemes. In such cases, the base station does not need to instruct the terminal to use index 4 or 5.

[0428] - When reporting its terminal capabilities, terminals can report the presence or absence of MU-MIMO assist signaling field support by DMRS type or PDSCH mapping type, either through individual terminal capabilities or by different component forms within the same terminal capability. For example, a terminal can report the presence or absence of MU-MIMO assist signaling field support in the manner described above for at least one of DMRS type 1, DMRS type 2, improved DMRS type 1, or improved DMRS type 2. Or / and, as an example, a terminal can report the presence or absence of MU-MIMO assist signaling field support in the manner described above for at least one of PDSCH mapping type A or B.

[0429] Alternatively, when reporting its capabilities, the terminal may report whether or not it has MU-MIMO assist signaling field support, regardless of whether it is DMRS type or PDSCH mapping type.

[0430] - When reporting its terminal capabilities, the terminal can report individual terminal capabilities to the base station for all DCI formats in which the MU-MIMO assist signaling field can exist. For example, the terminal can report separately its terminal capability for the presence or absence of the field in DCI format 1_1 and its terminal capability for the presence or absence of the field in DCI format 1_2.

[0431] - Alternatively, when reporting its terminal capabilities, the terminal may report to the base station its terminal capabilities common to all DCI formats in which the MU-MIMO assist signaling field can exist. The base station, upon receiving this, may include the field for all DCI formats that the terminal can support. Alternatively, the terminal may report to the base station, including information about the DCI formats in which the field can be supported within its terminal capabilities.

[0432] If the terminal reports the terminal capability to the base station, the base station may configure the terminal with higher-layer signaling that indicates the presence of a MU-MIMO assist signaling field within the DCI. This higher-layer signaling may be defined by at least one of the following criteria:

[0433] - The terminal may configure the above-layer signaling on a cell-by-cell basis.

[0434] - The terminal may configure the higher-layer signaling for each bandwidth portion. Therefore, there may be bandwidth portions where the higher-layer signaling exists and bandwidth portions where it does not.

[0435] * If the terminal performs a bandwidth switching (BWP switching) from a bandwidth portion where the upper layer signaling is configured to a bandwidth portion where the upper layer signaling is not configured, the terminal will take the changed bandwidth portion into account when analyzing the received DCI, and therefore can ignore that field.

[0436] * If a terminal performs a bandwidth switching (BWP switching) from a bandwidth portion where the upper layer signaling is not configured to a bandwidth portion where the upper layer signaling is configured, the terminal will take the changed bandwidth portion into consideration when analyzing the received DCI, and may analyze all bits in that field as 0 or ignore them.

[0437] - The terminals may individually configure the said upper-layer signaling using different DMRS types or PDSCH mapping types.

[0438] * If at least one of the entries in the TDRA field indicated by the DCI contains the DMRS type or PDSCH mapping type to which the higher-layer signaling is configured, the terminal can assume that the field exists in the DCI. If the entries in the TDRA field indicated by the DCI indicate the DMRS type or PDSCH mapping type to which the higher-layer signaling is configured (for example, DMRS type 1 or PDSCH mapping type A), the terminal can analyze each code point in the MU-MIMO assist signaling field in the manner described above. If the entry in the TDRA field indicated by DCI to the terminal does not indicate the DMRS type or PDSCH mapping type to which the upper-layer signaling is configured (for example, DMRS type 1 or PDSCH mapping type A), the terminal can either expect the base station to indicate the MU-MIMO assist signaling field as index 0, ignore the field without parsing it, consider the field to be a reserved value regardless of its value, or parse it by replacing it with additional bits for other fields where the code point is missing (for example, the antenna port field).

[0439] - The terminal may be configured from the base station so that the upper layer signaling can be applied in common to different DMRS types or PDSCH mapping types. That is, the terminal can expect that the MU-MIMO assist signaling field will be applied in common to different DMRS types or PDSCH mapping types configured by the upper layer signaling, based on a single upper layer signaling parameter.

[0440] - The terminal may configure the upper layer signaling separately for each DCI format. For example, the terminal may configure the upper layer signaling, which indicates the presence of a MU-MIMO assist signaling field for DCI formats 1_1, 1_2, 1_3, 4_1, or 4_2, with separate parameters for each DCI format.

[0441] - A terminal may configure the upper layer signaling in common for different DCI formats. That is, a terminal may configure a single upper layer signaling and expect the field to be present in all downlink DCI formats that the terminal can support with that upper layer signaling (e.g., DCI formats 1_0, 1_1, 1_2, 1_3, 4_0, 4_1, 4_2), or it may expect the field to be present only in a specific downlink DCI format that the terminal supports (e.g., DCI format 1_1 or 1_2).

[0442] The terminal may consider at least one of the following criteria for the DCI format in which the MU-MIMO assist signaling field can exist:

[0443] - The terminal can expect the MU-MIMO assist signaling field to be present for at least one of the DCI formats 1_1, 1_2, 1_3, 4_0, 4_1, and 4_2.

[0444] - The terminal can expect the MU-MIMO assist signaling field to exist only in DCI format 1_1.

[0445] - If the MU-MIMO assist signaling field exists in DCI format 1_2, the MU-MIMO assist signaling field may have the same field size and each code point may have the same meaning as in Table 32, as shown in Table 32 above.

[0446] - If the MU-MIMO assist signaling field exists in DCI format 1_2, the terminal may configure the MU-MIMO assist signaling field based on some or all of the eight code points represented in Table 32 above, and the length of the field may be 0, 1, 2, or 3 bits.

[0447] * If the bit length of the field is 1, the terminal can indicate two code points in the field, the first code point may have the same meaning as index 0 in Table 32 above, and the second code point may differ depending on the terminal capability reported by the terminal to the base station.

[0448] ○ If a terminal reports that it is capable of performing indices 1-5 in Table 32 above, the terminal may consider at least one of the following:

[0449] □ If the second code point is to be considered to mean, for example, one of indices 1 to 5, the terminal may be notified by the base station of one of indices 1 to 5 by the second code point through at least one combination of upper layer signaling, MAC-CE, L1 signaling, or according to the details fixedly defined in the standard.

[0450] □ Alternatively, a second code point may be defined using at least one combination of indices 1 to 5. For example, a second code point may be defined by combining indices 1 and 2, in which case the meaning of the code point may be that, for the terminal in question, the demodulation scheme of other MU-MIMO scheduled terminals is either QPSK or 16QAM, and both are identical, or that some of all other terminals can use QPSK and the remaining terminals can use 16QAM. Combining indices 1 and 2 in this way is just one example, and the method of defining a single code point by combining a specific number of indices 1 to 5 in the manner described above should not be excluded. In this case, when defining a single code point by combining multiple indices, in the case of indices 3, 4, or 5, the number of demodulation symbol cases that can be generated by the demodulation scheme may be much larger than that of indices 1 and 2, and these may be excluded during the combination process.

[0451] ○ If a terminal reports that it is capable of index 6 as well as indices 1-5 in Table 32 above, the terminal may interpret the meaning of the second code point as either index 6 in Table 32 above, or one of indices 1-5 above.

[0452] □ If the second code point is to be considered to mean one of indices 1 to 5, the terminal may be notified of one of indices 1 to 5 as the second code point by the base station through at least one combination of upper layer signaling, MAC-CE, or L1 signaling, or the terminal may follow the details fixedly defined in the standard.

[0453] □ Alternatively, a second code point may be defined using at least one combination of indices 1 to 5. For example, a second code point may be defined by combining indices 1 and 2. In this case, the meaning of the code point may be that, for the terminal in question, the demodulation scheme of other MU-MIMO scheduled terminals is either QPSK or 16QAM, and both are identical, or that some of all other terminals can use QPSK and the rest can use 16QAM. Combining indices 1 and 2 in this way is just one example, and the method of defining a single code point by combining a specific number of indices 1 to 5 in the manner described above should not be excluded. In this case, when defining a single code point by combining multiple indices, indices 3, 4, or 5 may be excluded during the combination process because the number of possible demodulation symbols that can be generated by the demodulation scheme may be much larger than that of indices 1 and 2.

[0454] ○ If a terminal reports that it is capable of index 7 as well as indices 1-6 in Table 32 above, the terminal can consider the meaning of the second code point to mean index 7 in Table 32 above.

[0455] ○ If a terminal reports to the base station that it is capable of R-ML receiver support regardless of the index in Table 32 above and that it is capable of supporting the MU-MIMO assist signaling field, the terminal may configure the first and second code points using at least one combination of the aforementioned items mentioned with respect to the code point configuration method, provided that the bit length of the field is 1 bit.

[0456] * If the bit length of the field is 2, the terminal can indicate four code points in the field, the first code point may have the same meaning as index 0 in Table 32 above, and the second to fourth code points may differ depending on the terminal capabilities reported by the terminal to the base station.

[0457] ○ If the terminal reports that it is capable of performing indices 1-5 in Table 32 above, the terminal may consider at least one of the following:

[0458] □ If the second to fourth code points are to be considered to represent three of indices 1 to 5, the terminal may be notified of three of indices 1 to 5 as the second to fourth code points by the base station through at least one combination of upper layer signaling, MAC-CE, and L1 signaling, or according to the details fixedly defined in the standard. In this case, if the terminal is unable to support PDSCH 256QAM and PDSCH 1024QAM as described above, i.e., has not reported its capability for the two demodulation schemes, the terminal may be considered to represent indices 1, 2, and 3, respectively.

[0459] □ Alternatively, the second to fourth code points may be defined using at least one combination of indices 1 to 5. For example, the second code point may be defined by combining indices 1 and 2. In this case, the meaning of the code point may be that, for the terminal in question, the demodulation scheme of other MU-MIMO scheduled terminals is either QPSK or 16QAM, and both are identical, or that some of all other terminals can use QPSK and the rest can use 16QAM. Combining indices 1 and 2 in this way is just one example of defining a code point, and the method of defining a code point by combining specific multiple indices from indices 1 to 5 in the manner described above should not be excluded. In this case, when defining a code point by combining multiple indices, indices 3, 4, or 5 may be excluded during the combination process because the number of possible demodulation symbols that can be generated by the demodulation scheme may be much larger than that of indices 1 and 2.

[0460] ○ If the terminal reports that it is capable of index 6 as well as indices 1-5 in Table 32 above, the terminal may consider the meaning of the second to fourth code points as follows:

[0461] □ If the second to fourth code points are to be considered to represent three of indices 1 to 6, the terminal may be notified of the second to fourth code points as three of indices 1 to 6 by the base station through at least one combination of upper layer signaling, MAC-CE, and L1 signaling, or according to details fixed in the standard. In this case, if the terminal is unable to support PDSCH 256QAM and PDSCH 1024QAM as described above, i.e., does not report terminal capability for the two demodulation schemes, the terminal may be considered to represent indices 1, 2, and 3, respectively. Alternatively, the second to fourth code points may be defined using at least one combination of indices 1 to 5. For example, a second code point may be defined by combining indices 1 and 2. In this case, the meaning of the code point may be that, for the terminal in question, the demodulation scheme of other MU-MIMO scheduled terminals is either QPSK or 16QAM, and both are identical, or that some of all other terminals can use QPSK and the rest can use 16QAM. Combining indices 1 and 2 in this way is just one example, and the method of defining a single code point by combining a specific number of indices from 1 to 5 in the manner described above should not be excluded. In this case, when defining a single code point by combining multiple indices, indices 3, 4, or 5 may be excluded during the combination process because the number of possible demodulation symbols that can be generated by the demodulation scheme may be much larger than that of indices 1 and 2.

[0462] □ If the second to fourth code points represent one of indices 1 to 6, or are determined by a combination of indices 1 to 5 and index 6, the terminal may define the fourth code point as index 6, and the remaining second and third code points may be constructed in a manner that is possible when the bit length of the field is 2 bits.

[0463] ○ If the terminal reports that it is capable of index 7 as well as indices 1-6 in Table 32 above, then at least one of indices 1-5, index 6, and index 7 may be indicated or defined as the second to fourth code points in the manner described above, or selected by the terminal, and as described above, a method in which multiple indices from indices 1-5 are combined to form a single code point may also be considered. Furthermore, as another method, the terminal may fix the fourth code point to index 7, and the remaining second and third code points may be indicated, defined, selected by the terminal, or configured using the method of combining multiple indices as described above.

[0464] ○ If a terminal reports to the base station that it is capable of R-ML receiver support regardless of the index in Table 32 above and that it is capable of supporting the MU-MIMO assist signaling field, the terminal may configure the first to fourth code points using at least one combination of the aforementioned items mentioned with respect to the code point configuration method, provided that the bit length of the field is 2 bits.

[0465] * If the length of the field is 3, the terminal can expect the MU-MIMO assist signaling field present in DCI format 1_2 to have the same size and meaning for each code point as the field present in DCI format 1_1, as shown in Table 32 above.

[0466] - If the MU-MIMO assist signaling field exists in DCI format 1_3, the terminal can configure the MU-MIMO assist signaling field based on some or all of the eight code points represented in Table 32 above, and the specific field configuration and the meaning of each code point can take into consideration at least one of the following. DCI format 1_3 is compatible with MC-DCI as described later.

[0467] * [Field Configuration 1 in MC-DCI] A terminal can expect that the MC-DCI contains one MU-MIMO assist signaling field of 0 to 3 bits in length. Furthermore, if one MU-MIMO assist signaling field is defined in the MC-DCI, the terminal can assume that the MU-MIMO assist signaling indicated by that field is applied identically to specific BWPs within one or more specific cells scheduled by the MC-DCI. If the MU-MIMO assist signaling field is 0 to 3 bits in length, the terminal can consider the definition for each code point of that field in a manner similar to that described above.

[0468] * [Field form 2 in MC-DCI] A terminal can expect that the MC-DCI contains one MU-MIMO assist signaling field of length 0 to 3 bits, and each code point in the MU-MIMO assist signaling field may contain MU-MIMO assist signaling information for each cell that can be scheduled by the MC-DCI. The information indicated by each code point may exist in the form of a list of MU-MIMO assist signaling instructions, and one or more lists may be set by the terminal from the base station via upper layer signaling. As an example, MU-MIMO assist signaling list 1, which is a list of MU-MIMO assist signaling instructions corresponding to a specific code point, may have the form {index 1, index 1, index 1, index 5}, and the meaning of this list is that for the first to third cells that can be scheduled by the MC-DCI, the MU-MIMO assist signaling field indicates index 1 in Table 32 above, and for the fourth cell, it indicates index 5. As described above, information about a specific cell within the MU-MIMO assist signaling list can be defined by combining at least one of indices 1 to 5.

[0469] * [Field configuration 3 in MC-DCI] A terminal can expect that the MC-DCI contains one MU-MIMO assist signaling field of 0 to 3 bits in length, and that MU-MIMO assist signaling field may indicate MU-MIMO assist signaling information in the BWP within a specific cell scheduled by the MC-DCI. The specific cell may be the first cell, the last cell, or a cell with a specific index set by the higher layer signaling configured by the base station. In this case, there may be one or more cells with a specific index set by the higher layer signaling. When the MU-MIMO assist signaling field is of 0 to 3 bits in length, the terminal can consider the definition for each code point in the field in the same manner as described above.

[0470] * A terminal can expect that the MC-DCI contains one MU-MIMO assist signaling field with a maximum length of 12 bits, and that a specific bit portion of this MU-MIMO assist signaling field can instruct MU-MIMO assist signaling for each cell that can be scheduled by the MC-DCI. For example, the MU-MIMO assist signaling field in the MC-DCI may be defined as 12 bits, and 3 bits may be applied to each cell that can be scheduled by the MC-DCI, and the meaning of the code points that each of the 3 bits can represent can be considered in the same way as in the above-described scheme.

[0471] * [Field Configuration 4 in MC-DCI] A terminal can expect that the MC-DCI contains multiple MU-MIMO assist signaling fields, each 0 to 3 bits long, and each MU-MIMO assist signaling field can instruct MU-MIMO assist signaling for each cell that can be scheduled by the MC-DCI. When each MU-MIMO assist signaling field is 0 to 3 bits long, the terminal can consider the definition for each code point of the field in the same manner as described above.

[0472] * [Field Configuration 5 within MC-DCI] A terminal can determine the configuration of the MU-MIMO assist signaling field within MC-DCI by setting some or all of the above-mentioned [Field Configuration 1 within MC-DCI] to [Field Configuration 4 within MC-DCI] using upper-layer signaling. For example, a terminal may be configured by upper-layer signaling from a base station for one of the above-mentioned [Field Configuration 1 within MC-DCI] and [Field Configuration 4 within MC-DCI], thereby determining the configuration of the MU-MIMO assist signaling field within MC-DCI.

[0473] - If the MU-MIMO assist signaling field exists in DCI format 4_0, 4_1, or 4_2, the terminal may configure the MU-MIMO assist signaling field based on some or all of the eight code points represented in Table 32 above, and the length of the field may be 0, 1, 2, or 3 bits, and may be the same as the field configuration defined in DCI format 1_2.

[0474] - If the MU-MIMO assist signaling field exists in DCI format 4_0, 4_1, or 4_2, the terminal can construct the MU-MIMO assist signaling field based on the total of eight code points represented in Table 32 above, the length of which the field may be 3 bits, and may be the same as the field configuration defined in DCI format 1_1.

[0475] Under the conditions described above (for example, if the terminal has configured upper-layer signaling from the base station that means a MU-MIMO assist signaling field exists), the terminal can expect the MU-MIMO assist signaling field to be located at a specific location within the DCI format and can determine that location by considering at least one of the following:

[0476] - One method is for a terminal to determine the DMRS port assigned to it by analyzing the Antenna port field. By analyzing the Antenna port field (if the Antenna port field indicates the assignment of a DMRS port capable of MU-MIMO scheduling), it is possible to confirm the existence of terminals scheduled together with the terminal at the same time and frequency using the MU-MIMO method. Therefore, MU-MIMO assist signaling may be located after the Antenna port field.

[0477] * If there are terminals that can be scheduled together, i.e., if the DMRS port assignment is capable of MU-MIMO scheduling, the terminal can estimate a modified channel with the precoder of another terminal applied on a DMRS port orthogonal to the assigned DMRS port. Thus, the terminal can expect the MU-MIMO assist signaling field to be located after the Antenna port field in the DCI formats 1_1, 1_2, 1_3, 4_0, 4_1, and 4_2. The specific location of the MU-MIMO assist signaling field may be between the Antenna port field and the Transmission configuration indication field, or between the Transmission configuration Indication field and the SRS request field.

[0478] * If there are no terminals that can be scheduled together, i.e., if a terminal is assigned a DMRS port that is not capable of MU-MIMO scheduling (for example, entry 11 in Tables 18, 19, 20, and 21 above, which can indicate DMRS ports 1000 and 1002 for DMRS type 1), the terminal may ignore the MU-MIMO assist signaling field that may be present after the Antenna port field, or may expect index 0 to be indicated.

[0479] - As another method, if a DMRS sequence initialization field exists within a particular DCI format, the terminal can determine the DMRS sequence by the scrambling ID indicated in the DMRS sequence initialization field, and based on this DMRS sequence information, it can perform channel estimation for the PDSCH DMRS. Therefore, the MU-MIMO assist signaling field can be expected to exist after the DMRS sequence initialization field. The specific location of the MU-MIMO assist signaling field may be immediately after the DMRS sequence initialization field, or it may be after the PUCCH cell indicator field, which is the last field in DCI formats 1_1 and 1_2.

[0480] - The terminal can determine the location of the MU-MIMO assist signaling field in the same manner as above, even if the MU-MIMO assist signaling field is present in DCI formats 1_3, 4_0, 4_1, and 4_2.

[0481] If a terminal supports low PAPR (peak-to-average power ratio) RS for PDSCH and the base station has enabled the upper-layer signaling dmrs-Downlink-r16, the terminal may use different DMRS sequences for each CDM group using different DMRS scrambling IDs for each CDM group, and different DMRS ports within a CDM group may use the same DMRS sequence based on the same DMRS scrambling ID. Taking this into consideration, the expression "same DMRS sequence" in Table 32 above may be replaced with the expression "same DMRS scrambling ID". In this case, the terminal can be expected to have the same value set for the upper-layer signaling dmrs-Downlink-r16 as other terminals scheduled for MU-MIMO. That is, all terminals scheduled for MU-MIMO, including the terminal in question, do not need to have the upper-layer signaling dmrs-Downlink-r16 enabled or configured.

[0482] If a terminal is instructed by the base station via DCI to specify the MU-MIMO assist signaling field and is MU-MIMO scheduled with other terminals, the terminal can expect to be instructed with the same value for Number of CDM groups without data (in the Antenna port field) as all other terminals scheduled with it in MU-MIMO. That is, the terminal can receive PDSCH transmissions from the base station assuming the same energy or power ratio of PDSCH RE to DMRS RE as all other terminals scheduled with it in MU-MIMO. The above assumptions may be implicitly applied when the terminal is MU-MIMO scheduled and receives signals from the base station, or they may be explicitly written in the statements expressing the meaning of each index in Table 32 above, and the terminal may or may not receive this information.

[0483] As another example, a terminal can communicate to a base station a terminal capability that means it can tolerate different PDSCH RE and DMRS RE energy or power ratios when scheduled for MU-MIMO with other terminals. Such a terminal may be scheduled for MU-MIMO with other terminals that have reported this terminal capability to the base station, which means that identical or different PDSCH RE to DMRS RE energy or power ratios are permitted among multiple terminals scheduled for MU-MIMO. A terminal that has not reported this terminal capability may be scheduled for MU-MIMO with other terminals that have not reported this terminal capability, which means that all terminals scheduled for MU-MIMO have been instructed to have the same PDSCH RE to DMRS RE energy or power ratio. Among terminals that have reported this terminal capability and those that have not reported it, terminals with the same PDSCH RE to DMRS RE energy or power ratio can be scheduled for MU-MIMO, while those that do not can not be scheduled for MU-MIMO.

[0484] For example, if terminals 1 and 2 transmit to the base station a terminal capability that means they can tolerate different energy or power ratios between PDSCH RE and DMRS RE when scheduled for MU-MIMO with other terminals, but terminals 3 and 4 do not transmit this terminal capability to the base station, and terminals 1 through 4 are all set to DMRS type 1, and the energy or power ratios between PDSCH RE and DMRS RE for terminals 1 through 4 are 0dB, 3dB, 3dB, and 3dB respectively, then terminals 1 and 2 can both be scheduled for MU-MIMO because they have reported this terminal capability, and terminals 3 and 4 can both be scheduled for MU-MIMO because they have not reported this terminal capability. However, terminal 1, which has reported this terminal capability, and terminal 3, which has not reported this terminal capability, have different energy or power ratios between PDSCH RE and DMRS RE, so MU-MIMO scheduling is not possible. Terminals 2, which has reported this terminal capability, and terminal 4, which has not reported this terminal capability, have different PDSCH Since the energy or power ratio of RE to DMRS RE is the same, MU-MIMO scheduling may be possible.

[0485] <Second Embodiment: DMRS Sequencing and OCC Deactivation for Multiple User Scheduling Support>

[0486] As one embodiment of this disclosure, a further definable DMRS sequence and OCC deactivation-related operation when a terminal is instructed by a base station to perform multiple user scheduling support signaling is described. This embodiment may operate in combination with other embodiments.

[0487] If a terminal is configured with the upper-layer signaling dmrs-FD-OCC-disableForRank1PDSCH and is assigned one DMRS port for PDSCH scheduling, the terminal does not need to expect other terminals to be assigned other orthogonal DMRS ports within the same CDM group as the assigned DMRS port that uses other FD-OCC. This can be achieved by not applying OCC despreading to at least two adjacent DMRS REs for channel estimation in the CDM group containing the assigned DMRS port, and by not assigning other terminals to other orthogonal ports within the CDM group, thereby enabling channel estimation without OCC despreading. With respect to the relationship between such OCC despreading operation and the MU-MIMO assist signaling field-related operation described in the first embodiment above, the terminal can operate with at least one of the following conditions.

[0488] - [OCC Despreading Related Operation 1] A terminal does not need to expect that both the upper layer signaling, which means that the MU-MIMO assist signaling field exists, and the upper layer signaling dmrs-FD-OCC-disableForRank1PDSCH are set. A terminal may expect that one of the two parameters is set, or that neither parameter is set, but does not need to expect that both parameters are set. A base station may exclude the case where both parameters are set for a terminal, may set only one of the two parameters, or may not set either.

[0489] - [OCC Despreading Related Operation 2] A terminal may be configured with both the above-level signaling, which means that a MU-MIMO assist signaling field exists, and the above-level signaling, dmrs-FD-OCC-disableForRank1PDSCH, and if the two terminal operations overlap, the terminal may operate in at least one combination of the following:

[0490] * If a terminal is indicated with one DMRS port in the Antenna port field (i.e., receiving rank-1 scheduling), can the terminal expect the MU-MIMO assist signaling field to indicate index 0, or can the terminal ignore the MU-MIMO assist signaling field regardless of what index the base station indicates in that field?

[0491] *As another method, if a terminal is indicated with one DMRS port in the Antenna port field (i.e., receiving rank-1 scheduling) and index 0 in the MU-MIMO assist signaling field, the terminal can expect that no other orthogonal DMRS ports other than the indicated DMRS port will be assigned to other MU-MIMO scheduled terminals within the CDM group that includes the indicated DMRS port. If a terminal is indicated with one DMRS port in the Antenna port field (i.e., receiving rank-1 scheduling) and an index other than index 0 in the MU-MIMO assist signaling field, the terminal can assume that it will not perform the OCC disable operation even with rank-1 scheduling, and that other MU-MIMO scheduled terminals may exist within the CDM group that includes the indicated DMRS port that are assigned other orthogonal DMRS ports other than the indicated DMRS port. If a terminal is given two or more DMRS ports in the Antenna port field (i.e., receives rank-2 scheduling), the terminal can expect the MU-MIMO assist signaling field to indicate one of all indices, and does not need to perform the OCC disable operation. In other words, the terminal may or may not perform the OCC disable function depending on the number of DMRS ports given to the terminal in the Antenna port field and the index indicated in the MU-MIMO assist signaling field.

[0492] - [OCC Despreading Related Operation 3] A terminal may have both the above-layer signaling, which means that the MU-MIMO assist signaling field exists, and the above-layer signaling, dmrs-FD-OCC-disableForRank1PDSCH, configured. In such a case, if the terminal receives rank-1 scheduling, it can perform OCC disabling within the CDM group containing the single specified DMRS port, regardless of the index indicated in the MU-MIMO assist signaling field. The terminal can expect that there is one DMRS port indicated in the Antenna port field in the DCI, and that there are no terminals scheduled together in MU-MIMO within the CDM group containing that DMRS port, and can assume that there are or are no terminals scheduled together in MU-MIMO within other CDM groups. Furthermore, if a terminal has two or more DMRS ports indicated in the Antenna port field within the DCI, it can be assumed that there are or are no terminals scheduled in MU-MIMO mode for all other orthogonal DMRS ports to the indicated DMRS port within the CDM group containing that indicated DMRS port, or for all DMRS ports in other CDM groups that do not contain the indicated DMRS port. In this case, if a terminal receives rank-1 scheduling and is indicated with a value other than index 0 in the MU-MIMO assist signaling field, the terminal can assume that no other terminals are scheduled to use the remaining DMRS ports orthogonal to the terminal other than the indicated DMRS port within the CDM group containing that indicated DMRS port, thus potentially reducing complexity when using an R-ML receiver.

[0493] A terminal may be configured with scrambling ID0 and / or scrambling ID1 by upper-layer signaling, and if a DMRS sequence initialization field exists in the DCI format, one of the scrambling ID0 and scrambling ID1 may be indicated in that 1-bit field. If a terminal uses an R-ML receiver, i.e., if the terminal may be configured with a MU-MIMO assist signaling field, it must use the same DMRS sequence as other terminals to estimate the modified channels of that terminal and other terminals with precoders applied, and additional scrambling IDs may be required in addition to the two scrambling ID0 and scrambling ID1 to control such MU-MIMO scheduling interference.

[0494] Therefore, if the terminal reports its terminal capabilities to the base station by one of the various methods mentioned in the first embodiment, and the base station configures the terminal for higher layer signaling and a MU-MIMO assist signaling field exists in the DCI format, the terminal may be configured with one or two additional scrambling IDs in addition to the scrambling ID0 and scrambling ID1. In this case, when the terminal receives instructions from the base station for a DMRS sequence, it may use a method for at least one combination of the following:

[0495] - [DMRS Sequence Usage Method 1] If a MU-MIMO assist signaling field exists in the DCI, that is, if the terminal has configured higher layer signaling indicating the presence or absence of the MU-MIMO assist signaling field, the terminal can expect the DMRS sequence initialization field to be defined as a maximum of 2 bits, thereby enabling the operation of four code points. In this way, the terminal may configure the higher layer signaling to set DMRS scrambling IDs, ID2 and / or ID3 in addition to the existing ID0 and ID1, and each of the four code points of the DMRS sequence initialization field, which can be defined as a maximum of 2 bits, can represent DMRS scrambling ID0, ID1, ID2, and ID3.

[0496] - [DMRS Sequence Usage Method 2] When a MU-MIMO assist signaling field is present in the DCI, that is, when a higher-layer signaling indicating the presence or absence of a MU-MIMO assist signaling field is set, the terminal can expect the DMRS sequence initialization field to be defined as a maximum of 1 bit, as before, and the meaning of the two code points that the 1 bit of the DMRS sequence initialization field can represent may be changed by the index indicated by the MU-MIMO assist signaling field. For example, if the MU-MIMO assist signaling field indicates index 0, and the terminal is not in a MU-MIMO scheduling situation or does not need to use an R-ML receiver, when the terminal analyzes the 1-bit DMRS sequence initialization field, each code point can be considered to indicate one of the higher-layer signaling DMRS scrambling ID0 and ID1.

[0497] As another example, if the MU-MIMO assist signaling field indicates a non-zero index, and specific information is provided that the terminal is in MU-MIMO scheduling status and can use an R-ML receiver, then when the terminal parses the 1-bit DMRS sequence initialization field, it can be assumed that each code point indicates either ID2 or ID3, rather than the higher-layer signaling DMRS scrambling IDs0 and ID1. In this case, the meaning of some or all of the first and second code points in the DMRS sequence initialization field may change depending on whether only one of ID2 and ID3 is set, or whether both are set. For example, if a terminal is set to DMRS scrambling ID0 and ID1 in addition to ID2, the terminal can parse the meaning of the first code point in the DMRS sequence initialization field to either DMRS scrambling ID0 or ID2, depending on whether the MU-MIMO assist signaling field indicates index 0 or another index. However, regardless of the index indicated in the MU-MIMO assist signaling field, the meaning of the second code point in the DMRS sequence initialization field may be the same as DMRS scrambling ID2.

[0498] <Third Example: Multi-User Scheduling Support Signaling Considering Improved DMRS Type>

[0499] As one embodiment of this disclosure, the operation of the terminal and base station when the terminal can be instructed by the base station to perform multiple user scheduling support signaling, and when the terminal receives higher-layer signaling from the base station for an improved DMRS type, will be described. This embodiment may be operated in combination with other embodiments.

[0500] The advanced 5G standards can support improved DMRS type 1 and DMRS type 2 for both uplink and downlink, supporting an increased number of orthogonal ports while maintaining the same RE usage and overhead compared to the initial 5G standards. Existing DMRS type 1 can support up to 4 and 8 orthogonal DMRS ports, respectively, when there are 1 and 2 front-loaded symbols, while DMRS type 2 can support up to 6 and 12 orthogonal DMRS ports, respectively, when there are 1 and 2 front-loaded symbols.

[0501] With this support, improved DMRS type 1 can support up to 8 and 16 orthogonal DMRS ports when the number of leading symbols is 1 and 2, respectively, and improved DMRS type 2 can support up to 12 and 24 orthogonal DMRS ports when the number of leading symbols is 1 and 2, respectively. Hereafter, new DMRS types that support this increased number of orthogonal ports may be named as "improved 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," and other similar extended names that indicate improved functionality from existing DMRS types 1 and 2 do not need to be excluded. The matters described below focus on downlinks, but similar applications are possible for uplink DMRS resources as well.

[0502] If a terminal supports improved DMRS type 1 and 2, the terminal can report its capability to support improved DMRS type 1 and 2 to the base station. This terminal capability report may be transmitted to the base station on a per-band basis, or more specifically, on a feature set (FS) or feature set per component carrier (FSPC) basis. Furthermore, this terminal capability report may be supported differently for each FR, or may be limited to FR1.

[0503] Furthermore, the terminal capability report may include the following meanings: in the case of improved DMRS type 1, when the number of symbols placed at the beginning is 1 and 2, it can support a maximum of 8 and 16 orthogonal DMRS ports, respectively; and in the case of improved DMRS type 2, when the number of symbols placed at the beginning is 1 and 2, it can support a maximum of 12 and 24 orthogonal DMRS ports, respectively. Terminals can also report whether or not they support improved DMRS type 1 and 2 using a common terminal capability, in which case they can report whether or not they support only improved DMRS type 1, only improved DMRS type 2, or both improved DMRS type 1 and 2, and they can report whether or not they support improved DMRS type 1 and 2 using individual terminal capabilities.

[0504] As a way to support the improved DMRS type 1 described above, when using the improved DMRS type 1 based on the following equation 6 and Table 33, the time and frequency resource mapping of the DMRS RE and the coefficients of FD-OCC and TD-OCC at that time can be determined.

[0505]

number

[0506] [Table 32]

[0507] In the improved DMRS type 1 based on the above formula 6 and Table 33, a total of two CDM groups are used. For one leading DMRS symbol, each CDM group may contain four DMRS ports, thus supporting a maximum of eight orthogonal DMRS ports. For two leading DMRS symbols, each CDM group may contain eight DMRS ports, thus supporting a total of 16 orthogonal DMRS ports. By maintaining the number of CDM groups of two, which is the same as in the existing DMRS type 1, while increasing the number of DMRS ports within each CDM group, and thereby increasing the OCC length to four, the scheduling of PDSCH transmitted with DMRS can be performed in units of two RBs, and DMRS can be mapped to the same RE positions as in the existing DMRS type 1.

[0508] However, existing DMRS type 1 assumes that two REs located 2 REs apart (e.g., RE#0 and RE#2) have identical channels, and distinguishes orthogonal ports by applying OCC to the two REs. In the case of a DMRS symbol placed at the beginning, a total of 6 REs are used within one RB per port, so three OCCs of length 2 are used.

[0509] On the other hand, based on the improved DMRS type 1, for a DMRS symbol placed at the beginning, a total of 12 REs are used within 2 RBs per port, and the receiver can distinguish between a total of 4 orthogonal antenna ports by using an OCC of length 4 applied to 4 adjacent REs. In this case, the OCC of length 4 is applied to 4 REs, and each of the 4 REs may be located 2 REs apart from each other (i.e., with a subcarrier index difference of 2). That is, the receiver must apply the OCC to 4 REs whose relative RE positions are 0, 2, 4, and 6, respectively, as if they were on the same channel, which may result in lower channel estimation performance compared to the existing DMRS type 1. Therefore, such an improved DMRS type 1 may be used for multiplexed user MIMO applications in channels with less frequency-selective characteristics.

[0510] In Table 33 above, among the OCCs of length 4, ports 1000 to 1015 are arranged such that all ports can be orthogonal to each other. f The (k') value may be determined, and the values ​​in the table above are just examples; other values ​​are not excluded. In formula 6 above,

number

number

number

[0511] As a method to support the improved DMRS type 2 described above, when using the improved DMRS type 2 based on the following equation 7 and Table 34, the time and frequency resource mapping of the DMRS RE and the coefficients of FD-OCC and TD-OCC at that time can be determined.

[0512]

number

[0513] [Table 33]

[0514] Based on the above equation 7 and Table 34, the improved DMRS type 2 uses a total of three CDM groups. For one leading DMRS symbol, each CDM group may contain four DMRS ports, thus supporting a total of 12 orthogonal DMRS ports. For two leading DMRS symbols, each CDM group may contain eight DMRS ports, thus supporting a total of 24 orthogonal DMRS ports. Since the number of DMRS ports within a CDM group is increased while maintaining the number of CDM groups, the scheduling of PDSCH transmitted with DMRS can be maintained in the same RB units as before, and DMRS can be mapped to the same RE locations as in existing DMRS type 2.

[0515] However, existing DMRS type 2 assumes that two consecutive RE channels are identical and applies OCC to the two REs to distinguish orthogonal ports. In the case of a DMRS symbol placed at the beginning, a total of four REs are used within one RB per port, so two OCCs of length 2 are used.

[0516] On the other hand, based on the improved DMRS type 2, for a single leading DMRS symbol, a total of four REs are used within one RB per port, and the receiver can distinguish a total of four orthogonal ports 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 (i.e., a subcarrier index difference of 6), meaning the receiver must apply the OCC to four REs whose relative RE positions are 0, 1, 6, and 7, respectively, as if they were the same channel, which can result in a decrease in channel estimation performance compared to existing DMRS type 2. Therefore, such an improved DMRS type 2 may be used for multiplexed user MIMO applications in channels with less frequency-selective characteristics. In Equation 8,

number

number

number

[0517] As described above, if a terminal reports to the base station that it is capable of supporting improved DMRS type 1 or improved DMRS type 2, and the base station configures higher-layer signaling that means it supports improved DMRS type 1 or improved DMRS type 2, the terminal may have twice as many DMRS ports orthogonal to front-loaded symbols of the same length compared to DMRS type 1 or DMRS type 2. Therefore, if a terminal uses the aforementioned R-ML receiver to estimate the demodulated signal of another terminal with a modified channel obtained by multiplying the precoder of that terminal scheduled in MU-MIMO by its own channel, the terminal may have more than twice the complexity when operating based on improved DMRS type 1 compared to DMRS type 1.

[0518] Therefore, if a terminal reports to the base station its terminal capability to support an improved DMRS type 1 or 2, and the terminal intends to report to the base station its terminal capability meaning that it can receive the MU-MIMO assist signaling field in order to support the R-ML receiver mentioned above, the terminal may have to transmit to the base station a separate terminal capability report meaning that it can handle a greater complexity than DMRS type 1 or 2. In other words, in order to support both the R-ML receiver and the improved DMRS type 1 or 2 simultaneously, the terminal can define and report to the base station a separate terminal capability that has a similar meaning to the terminal capability mentioned in the first embodiment, but that it can support both the improved DMRS type 1 or 2 and the improved DMRS type 1 or 2. In this case, the terminal capability may also be defined in three levels, as described above, such as support for indices 1-5, support for indices 1-5 plus index 6, and support for indices 1-6 plus index 7. Furthermore, the maximum number of terminals or the maximum number of layers that can MU-MIMO schedule with the terminal may be included in the report to the base station, and similar information may be included in the terminal capability in the first embodiment described above.

[0519] <Fourth embodiment: PDSCH to which multi-user scheduling support signaling can be applied>

[0520] As one embodiment of this disclosure, a PDSCH capable of applying multiple user scheduling support signaling, which can be instructed by a base station, is described. This embodiment may operate in combination with other embodiments.

[0521] The terminal may be instructed by the base station via DCI to activate for SPS PDSCH reception. In this case, if a MU-MIMO assist signaling field exists in the DCI received by the terminal, that is, if the terminal has been configured with higher-layer signaling that indicates the presence of a MU-MIMO assist signaling field, the terminal may perform actions using at least one combination of the following:

[0522] - When a terminal receives a DCI that instructs SPS PDSCH activation, it can expect that if a MU-MIMO assist signaling field exists within that DCI, the MU-MIMO assist signaling field will indicate index 0. In other words, when a terminal receives a periodic SPS PDSCH, it can expect SU-MIMO scheduling without using an R-ML receiver.

[0523] - When a terminal receives a DCI instructing SPS PDSCH activation, if a MU-MIMO assist signaling field exists within that DCI, the terminal may ignore the value of the MU-MIMO assist signaling field, regardless of what index it indicates. In other words, when a periodic SPS PDSCH is received, the terminal can expect SU-MIMO scheduling without using an R-ML receiver.

[0524] - When a terminal receives a DCI instructing SPS PDSCH activation, if a MU-MIMO assist signaling field exists within the DCI, and the MU-MIMO assist signaling field indicates a value other than 0, that value may be applied only to the first SPS PDSCH reception after activation by the DCI. From the second SPS PDSCH reception onward, the terminal can ignore the information in the MU-MIMO assist signaling field, i.e., expect SU-MIMO scheduling without using an R-ML receiver. Furthermore, the application of MU-MIMO scheduling to the first SPS PDSCH is merely an example; the SPS PDSCH to which MU-MIMO scheduling is applied may be determined by other methods, as described below. For example, a terminal may determine that an SPS PDSCH at a specific period after activation, as fixed in the standard, is a MU-MIMO scheduled PDSCH (e.g., the 5th SPS PDSCH after activation), or assume that an SPS PDSCH is MU-MIMO scheduled at specific intervals (e.g., applying MU-MIMO scheduling to every 10th SPS PDSCH after activation), or assume that an SPS PDSCH at a specific location or specific interval set by the base station is MU-MIMO scheduled.

[0525] - When a terminal receives a DCI instructing SPS PDSCH activation, if a MU-MIMO assist signaling field exists within the DCI, the terminal can apply the value indicated in the MU-MIMO assist signaling field to all periods of SPS PDSCH reception if the MU-MIMO assist signaling field indicates a value other than 0. In other words, in the case of such SPS PDSCH activation, the terminal can assume that MU-MIMO scheduling will be performed at all SPS PDSCH reception locations. For example, if quasi-statically scheduled traffic is transmitted to multiple terminals at similar intervals, and the terminal's channel does not change and is favorable for MU-MIMO scheduling, i.e., the channels between two terminals and a base station have low spatial correlation, the terminal may be scheduled for MU-MIMO even in the case of SPS PDSCH.

[0526] If a base station intends to suspend MU-MIMO scheduling from a certain point in time, it can instruct the terminal to perform an additional DCI and update the information regarding the SPS PDSCH. In this case, if the base station determines that further MU-MIMO scheduling is not possible for a terminal that has already scheduled MU-MIMO, the base station can instruct the terminal to set the MU-MIMO assist signaling field in the additional DCI to index 0.

[0527] If the upper-layer signaling corresponding to a single code point indicated by a TDRA field in the DCI contains multiple TDRA entries, the terminal can receive different PDSCHs at different time resource locations indicated by each TDRA entry, which can be named multi-PDSCH scheduling. In this case, if the DCI received by the terminal contains a MU-MIMO assist signaling field, i.e., if the terminal has configured upper-layer signaling that indicates the presence of a MU-MIMO assist signaling field, the terminal can perform actions using at least one combination of the following:

[0528] - When a terminal receives a DCI instructing multi-PDSCH scheduling, if a MU-MIMO assist signaling field exists within that DCI, the terminal can expect the MU-MIMO assist signaling field to indicate index 0. In other words, when a terminal receives multi-PDSCH scheduling, it can expect SU-MIMO scheduling without using an R-ML receiver for each of the different PDSCHs.

[0529] - When a terminal receives a DCI instructing multi-PDSCH scheduling, if a MU-MIMO assist signaling field exists within that DCI, the terminal can ignore the value indicated by the MU-MIMO assist signaling field, regardless of what index it indicates. In other words, when a terminal receives multi-PDSCH scheduling, it can expect SU-MIMO scheduling without using an R-ML receiver for each of the different PDSCHs.

[0530] - When a terminal receives a DCI instructing multi-PDSCH scheduling, if a MU-MIMO assist signaling field exists within the DCI, and the MU-MIMO assist signaling field indicates a value other than index 0, the terminal may apply this value only to the first PDSCH indicated in the DCI among several distinct PDSCHs. For the second to last PDSCH receptions, the terminal can ignore the information in the MU-MIMO assist signaling field, i.e., expect SU-MIMO scheduling without using an R-ML receiver. Furthermore, applying MU-MIMO scheduling to the first PDSCH is merely one example; other methods are also possible for determining which PDSCH to which MU-MIMO scheduling is applied, as described below. The terminal can assume MU-MIMO scheduling for PDSCHs at specific locations fixed in the standard within multi-PDSCH scheduling (for example, the last PDSCH in multi-PDSCH), or it can assume that MU-MIMO scheduling is performed for PDSCHs at specific locations notified by a base station through a combination of upper-layer signaling, MAC-CE, and L1 signaling.

[0531] - When a terminal receives a DCI instructing multi-PDSCH scheduling, if a MU-MIMO assist signaling field exists within that DCI, the terminal can apply the value indicated by the MU-MIMO assist signaling field to all time resource locations of the multi-PDSCH reception, provided that the MU-MIMO assist signaling field indicates a value other than index 0. In other words, in the case of such multi-PDSCH scheduling, the terminal can assume that MU-MIMO scheduling will be performed at all different PDSCH reception locations.

[0532] If terminals are configured with different CORESETPoolIndex values ​​in CORESET, i.e., operating as a multi-DCI-based multi-TRP, and if a MU-MIMO assist signaling field exists in the DCI that a terminal receives, i.e., if a terminal is configured with upper-layer signaling that means a MU-MIMO assist signaling field exists, the terminal can perform actions using at least one of the following combinations:

[0533] - The terminal can expect that the MU-MIMO assist signaling field is not present within the DCI.

[0534] - The terminal can expect that if the MU-MIMO assist signaling field is present in the DCI, that field will indicate only index 0. That is, the terminal may receive single-TRP-based SU-MIMO scheduled or the aforementioned NCJT scheduled PDSCH, but may not receive MU-MIMO scheduled PDSCH.

[0535] - If the MU-MIMO assist signaling field is present in the DCI, the terminal can ignore the value indicated by that field, regardless of what index it indicates. In other words, the terminal may receive single-TRP based SU-MIMO scheduled or the aforementioned NCJT scheduled PDSCH, but may not receive MU-MIMO scheduled PDSCH.

[0536] - If the MU-MIMO assist signaling field is present in the DCI, and the field indicates an index of 0, the terminal can expect to receive one of the single-TRP scheduled or NCJT scheduled PDSCHs described above. If the terminal is indicated with a non-zero index for the MU-MIMO assist signaling field, the terminal can expect MU-MIMO scheduling in which the PDSCH is sent from a single-TRP. In other words, if the index of MU-MIMO assist signaling is not zero, the terminal can expect that two PDSCHs that can be indicated by different DCIs sent from CORESETs with different CORESETPoolIndex settings will not overlap in terms of time and frequency resources, which means the terminal can expect that the PDSCHs will be scheduled from a single TRP rather than NCJT. This is because the terminal does not expect NCJT scheduling when it can expect MU-MIMO scheduling.

[0537] Single-DCI-based multi-TRP operation (i.e., when two TCI states are activated at least one code point in the TCI state field within the DCI) may also be performed similarly to the multi-DCI-based multi-TRP operation described above when combined with the MU-MIMO assist signaling field. That is, the terminal may expect that the MU-MIMO assist signaling field does not exist within the DCI, or that the MU-MIMO assist signaling field exists but only points to index 0, or that the MU-MIMO assist signaling field is ignored regardless of what it points to. Furthermore, the terminal does not need to expect that the MU-MIMO assist signaling field points to an index other than 0 when two TCI states are indicated in the TCI state field. In other words, when multi-TRP scheduling occurs (when two TCI states are indicated), the terminal does not need to expect MU-MIMO scheduling to occur, but can expect SU-MIMO scheduling to occur, i.e., it can expect index 0 to be indicated. Furthermore, if a terminal is indicated with a single TCI state in the TCI state field, the terminal can expect a predetermined index to be indicated in the MU-MIMO assist signaling field, which means there are no scheduling constraints.

[0538] A terminal can receive C-JT (coherent joint transmission) PDSCH scheduling from a base station, and for that purpose, can receive upper-layer signaling settings and L1 signaling. C-JT PDSCH is a method in which a base station uses multiple TRPs and operates them as if they were a single TRP to transmit PDSCH to a terminal, in which case the multiple TRPs may be fully or partially synchronized in time and frequency. When a base station schedules C-JT PDSCH to a terminal, the terminal can secure a higher rank compared to receiving PDSCH from an existing single TRP, and can obtain further power gain by receiving signals from multiple TRPs. For the base station, by using multiple TRPs, it can obtain further power gain while increasing the probability of generating independent channels between multiple terminals compared to when using a single TRP, thus maximizing the multi-user MIMO support gain.

[0539] A terminal can report terminal capability to the base station, indicating that C-JT PDSCH scheduling is possible. This terminal capability may include at least one combination of the following:

[0540] - Number of TCI states required during C-JT PDSCH scheduling: At least one combination of 1 or 2 states can be reported.

[0541] - When only one TCI state is required for C-JT PDSCH scheduling, the QCL type of the first TCI state is QCL-TypeA, and the terminal can access four channel parameters derived from the reference RS of that TCI state: average delay, delay spread, Doppler shift, and Doppler spread.

[0542] - When two TCI states are required for C-JT PDSCH scheduling, the terminal can report the channel parameter information and QCL type included in the first TCI state and the second TCI state, and the channel parameter information and QCL type included in the first TCI state and the second TCI state can be at least one combination of the following:

[0543] * [TCI state 2 indication method 1] Both the first and second TCI states have a QCL type of QCL-TypeA, and the terminal can refer to four channel parameters derived from the reference RS of the two TCI states: average delay, delay spread, Doppler shift, and Doppler spread.

[0544] * [TCI state 2 indication method 2] The QCL type of the first TCI state is QCL-TypeA, and the terminal can refer to the four channel parameters average delay, delay spread, Doppler shift, and Doppler spread derived from the reference RS of the first TCI state. The QCL type of the second TCI state can mean a state in which some channel parameters of QCL-TypeA are excluded, and the terminal can refer to the two channel parameters average delay and delay spread derived from the reference RS of the second TCI state.

[0545] After receiving the terminal capability report, the base station may configure upper layer signaling on the terminal using at least one combination of the following upper layer signaling configuration methods.

[0546] - The terminal may be configured via upper-layer signaling for the TCI instruction method for C-JT PDSCH scheduling from the base station. This upper-layer signaling may be configured on a bandwidth portion basis or on a cell basis.

[0547] - If a terminal reports to the base station, through a terminal capability report, that it can receive one TCI state during C-JT PDSCH scheduling, the base station can configure higher-layer signaling for the terminal to indicate that it will use one TCI state during C-JT PDSCH scheduling.

[0548] - If a terminal reports to the base station, in a terminal capability report, that it has 2 TCI states that can be received during C-JT PDSCH scheduling, and also reports at least one of the above [TCI state 2 indication method 1] and [TCI state 2 indication method 2], the base station can set up upper-layer signaling that means to the terminal that there are 2 TCI states to use during C-JT PDSCH scheduling, while also meaning one of the above [TCI state 2 indication method 1] or [TCI state 2 indication method 2].

[0549] - If a terminal reports to the base station in a terminal capability report that it can support at least one of the [TCI state 2 indication method 1] and [TCI state 2 indication method 2] when there are 2 TCI states, the base station can set up upper-layer signaling that means either 1 or 2 TCI states to be used when scheduling C-JT PDSCH, while also indicating to the terminal that there are 1 or 2 TCI states to be used when scheduling C-JT PDSCH, and that it can support at least one of the [TCI state 2 indication method 1] or [TCI state 2 indication method 2].

[0550] If the terminal is configured with the above-mentioned C-JT PDSCH scheduling-related upper-layer signaling (for example, upper-layer signaling that C-JT PDSCH scheduling is possible, the number of TCI states used during C-JT PDSCH scheduling, and one of the related configuration information such as the QCL type of the TCI state if two TCI states are used), and if the DCI received by the terminal contains a MU-MIMO assist signaling field, that is, if the terminal is configured with upper-layer signaling that the MU-MIMO assist signaling field exists, the terminal can perform actions using at least one of the following combinations.

[0551] - If a terminal is instructed to perform the above-mentioned C-JT PDSCH scheduling by a single TCI state, the terminal may expect that the MU-MIMO assist signaling field does not exist in the DCI, or that the MU-MIMO assist signaling field exists but only indicates index 0, or that the field is ignored regardless of what index it indicates. In other words, even if C-JT PDSCH scheduling is instructed by a single TCI state, the terminal should treat it the same as the multi-TRP scheduling and should not expect to receive MU-MIMO scheduling.

[0552] - As another method, if a terminal is instructed to perform the aforementioned C-JT PDSCH scheduling by a single TCI state, the terminal can expect the MU-MIMO assist signaling field to indicate a predetermined index, which means there are no scheduling constraints. Therefore, in the case of C-JT PDSCH scheduling, despite being multi-TRP scheduling, it can be treated the same as a single-TRP method by the terminal, and thus it may be permissible for the terminal to be MU-MIMO scheduled.

[0553] - If the terminal is instructed to perform the C-JT PDSCH scheduling described above by two TCI states, the terminal may expect that the MU-MIMO assist signaling field does not exist in the DCI, or that the MU-MIMO assist signaling field exists but only indicates index 0, or that the MU-MIMO assist signaling field may be ignored regardless of what index it indicates.

[0554] As another method, even if a terminal receives a C-JT PDSCH scheduled based on two TCI states, the terminal can report its individual terminal capabilities to the base station and communicate to the base station that MU-MIMO scheduling is possible in that situation. For such a terminal, the base station can transmit MU-MIMO-related information to the terminal in the MU-MIMO assist signaling field. When a C-JT PDSCH scheduled based on the two TCI states described above is received, if MU-MIMO scheduling is possible, it may be supported by at least one of the above-described methods [Two TCI State Instruction Method 1] and [Two TCI State Instruction Method 2], and the terminal can report its individual terminal capabilities for each method or report its common terminal capabilities and communicate to the base station that MU-MIMO scheduling is possible.

[0555] <Example 5: Conditions for the Use of Multi-User Scheduling Support Signaling>

[0556] As one embodiment of this disclosure, the conditions under which a terminal can receive multiple user scheduling support signaling from a base station will be described. This embodiment may be operated in combination with other embodiments.

[0557] A terminal can receive upper-layer signaling configurations from a base station for a specific multiplex TRP-based PDSCH transmission scheme. Such upper-layer signaling should be prepared for the terminal not only for receiving schemes for single-TRP-based PDSCH transmission schemes but also for receiving schemes for multiplex TRP-based PDSCH transmission schemes, which requires the implementation of additional receiving algorithms by the terminal, resulting in additional complexity.

[0558] Furthermore, the terminal can receive the MU-MIMO assist signaling field in DCI format 1_1 by configuring higher-layer signaling from the base station to determine the presence or absence of the MU-MIMO assist signaling field, thereby enabling it to receive additional information regarding multiple-user MIMO scheduling. When this higher-layer signaling is configured, the terminal can identify interference issues between users during multiple-user MIMO scheduling based on the R-ML receiver and operate a corresponding reception algorithm, which in turn introduces further terminal complexity.

[0559] Therefore, if a terminal is simultaneously configured by the base station with upper-layer signaling corresponding to the multiple TRP-based PDSCH transmission scheme and upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field, the terminal's receiver structure becomes complex, and the number of algorithms that need to be implemented increases, which can result in a significant increase in complexity. Both the multiple TRP-based PDSCH transmission scheme and the multiple user MIMO scheduling scheme can improve the terminal's downlink data reception performance, but implementing them simultaneously inevitably places a very heavy burden on the corresponding terminal. Therefore, the constraints between the multiple TRP-based PDSCH transmission scheme and the upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field will be described below. The upper layer signaling corresponding to the multiple TRP-based PDSCH transmission scheme that can be considered below may be one of the following: coresetPoolIndex, TCI selection field-related upper layer signaling, repetitionSchemeConfig-r16 or repetitionSchemeConfig-v1630, SSB-MTC-AdditionalPCI, sfnSchemePDCCH and / or sfnSchemePDSCH, searchSpaceLinkingId, or cjtSchemePDSCH.

[0560] Next, we will discuss the configuration of one or more CORESETs with different coresetPoolIndex values ​​from the upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1.

[0561] If a terminal is configured by a base station with one or more CORESETs having different coresetPoolIndex values, the terminal does not need to be configured by the base station with higher-layer signaling that determines the presence or absence of a MU-MIMO assist signaling field for DCI format 1_1.

[0562] If a base station configures one or more CORESETs on a terminal with different coresetPoolIndex values, the base station does not need to configure higher-layer signaling on the terminal to determine the presence or absence of a MU-MIMO assist signaling field for DCI format 1_1.

[0563] If a terminal is configured by a base station to perform upper-layer signaling that determines the presence or absence of a MU-MIMO assist signaling field for DCI format 1_1, the terminal does not need to expect (or will not be configured) one or more CORESETs with different coresetPoolIndex values ​​from the base station.

[0564] If a base station configures upper-layer signaling on a terminal to determine the presence or absence of a MU-MIMO assist signaling field for DCI format 1_1, the base station does not need to configure one or more CORESETs on the terminal with different coresetPoolIndex values.

[0565] The above statement that a terminal is not configured by a base station with one or more CORESETs having different coresetPoolIndex values ​​means that either none of the one or more CORESETs configured on the terminal have a coresetPoolIndex, either all of the one or more CORESETs configured on the terminal have a coresetPoolIndex of 0, or all of the one or more CORESETs configured on the terminal have a coresetPoolIndex of 1. Alternatively, the statement that a base station does not configure a terminal with one or more CORESETs having different coresetPoolIndex values ​​means that none of the one or more CORESETs configured by the base station have a coresetPoolIndex, either all of the one or more CORESETs configured by the base station have a coresetPoolIndex of 0, or all of the one or more CORESETs configured by the base station have a coresetPoolIndex of 1.

[0566] The above statement that a terminal is configured by a base station with one or more CORESETs having different coresetPoolIndex values ​​means that some of the one or more CORESETs configured on the terminal will not have a coresetPoolIndex set, or will be set to 0, while the remaining some will have a coresetPoolIndex set to 1. For example, if a terminal is configured by a base station with two CORESETs, the first CORESET will not have a coresetPoolIndex set, or will be set to 0, while the second CORESET will have a coresetPoolIndex set to 1. The statement that a base station is configured by a terminal with one or more CORESETs having different coresetPoolIndex values ​​means that some of the one or more CORESETs configured by the base station will not have a coresetPoolIndex set, or will be set to 0, while the remaining some will have a coresetPoolIndex set to 1.

[0567] The following describes the upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1, and the TCI state field within DCI format 1_1 or 1_2.

[0568] If a terminal is configured with upper-layer signaling from the base station to determine the presence or absence of a MU-MIMO assist signaling field for DCI format 1_1, the terminal can expect that all code points in the TCI state field within DCI format 1_1 or 1_2 received from the base station indicate one TCI state. In other words, the terminal does not need to expect that one code point in the TCI state field within DCI format 1_1 or 1_2 received from the base station also indicates two TCI states.

[0569] If a base station has configured upper-layer signaling on a terminal to determine the presence or absence of a MU-MIMO assist signaling field for DCI format 1_1, the base station may instruct or activate all code points in the TCI state field within DCI format 1_1 or 1_2 transmitted to the terminal to indicate one TCI state. In other words, the base station does not need to instruct or activate any single code point in the TCI state field within DCI format 1_1 or 1_2 transmitted to the terminal to indicate two TCI states.

[0570] The following describes the upper-layer signaling that determines the presence or absence of a TCI selection field that can exist in DCI formats 1_1 and 1_2, and the upper-layer signaling that determines the presence or absence of a MU-MIMO assist signaling field for DCI format 1_1. The TCI selection field may contain information that instructs the terminal which of the two TCI states to use to receive the PDSCH when the terminal is given two TCI states. For example, the TCI selection field may instruct the terminal to receive the PDSCH using either the first or second TCI state, or it may instruct it to receive the PDSCH using both the first and second TCI states.

[0571] If a terminal is configured with upper-layer signaling from the base station to determine the presence or absence of TCI selection fields that can exist within DCI formats 1_1 and 1_2, the terminal does not need to be configured with upper-layer signaling from the base station to determine the presence or absence of MU-MIMO assist signaling fields for DCI format 1_1.

[0572] If the base station configures the terminal with upper-layer signaling that determines the presence or absence of TCI selection fields that can exist within DCI formats 1_1 and 1_2, the base station does not need to configure the terminal with upper-layer signaling that determines the presence or absence of MU-MIMO assist signaling fields for DCI format 1_1.

[0573] If a terminal is configured by the base station to determine the presence or absence of a MU-MIMO assist signaling field for DCI format 1_1, the terminal does not need to be configured by the base station to determine the presence or absence of a TCI selection field that can exist within DCI formats 1_1 and 1_2.

[0574] If the base station configures the terminal with upper-layer signaling to determine the presence or absence of a MU-MIMO assist signaling field for DCI format 1_1, the base station does not need to configure the terminal with upper-layer signaling to determine the presence or absence of a TCI selection field that can exist within DCI formats 1_1 and 1_2.

[0575] The following describes the upper layer signaling repetitionSchemeConfig-r16 or repetitionSchemeConfig-v1630 and the upper layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1. repetitionSchemeConfig is information that instructs the repetitive transmission method of single-DCI based multi-TRP PDSCH. The aforementioned upper layer signaling, repetitionSchemeConfig-r16 or repetitionSchemeConfig-v1630, is a condition for a terminal to perform multiple TRP-based PDSCH repetitive transmission from a base station, and when the upper layer signaling is set, the terminal can receive multiple TRP-based PDSCH repetitive transmission assuming one of the above "tdmSchemeA", "fdmSchemeA", or "fdmSchemeB".

[0576] If the terminal is configured by the base station with the upper layer signaling repetitionSchemeConfig-r16 or repetitionSchemeConfig-v1630, the terminal does not need to be configured by the base station with the upper layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1.

[0577] If the base station configures the terminal with the higher layer signaling repetitionSchemeConfig-r16 or repetitionSchemeConfig-v1630, the base station does not need to configure the terminal with the higher layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1.

[0578] If the terminal has been configured by the base station with upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1, the terminal does not need to be configured by the base station with the upper-layer signaling repetitionSchemeConfig-r16 or repetitionSchemeConfig-v1630.

[0579] If the base station has configured the terminal with upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1, the base station does not need to configure the terminal with the upper-layer signaling, repetitionSchemeConfig-r16 or repetitionSchemeConfig-v1630.

[0580] The following describes upper-layer signaling that determines the presence or absence of a MU-MIMO assist signaling field for upper-layer signaling SSB-MTC-AdditionalPCI and DCI format 1_1. SSB-MTC-AdditionalPCI may be used when a terminal receives SSB, PDCCH, or PDSCH from a TRP having a different PCID (physical cell ID) than the serving cell's PCID (physical cell ID).

[0581] If a terminal is configured with SSB-MTC-AdditionalPCI, which is a higher layer signaling, from the base station, the terminal does not need to be configured with higher layer signaling from the base station to determine the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1.

[0582] If the base station configures the terminal with SSB-MTC-AdditionalPCI, which is a higher layer signaling, the base station does not need to configure the terminal with higher layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1.

[0583] If the terminal is configured by the base station with upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1, the terminal does not need to be configured by the base station with the upper-layer signaling SSB-MTC-AdditionalPCI.

[0584] If the base station has configured the terminal with upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1, the base station does not need to configure the terminal with the upper-layer signaling SSB-MTC-AdditionalPCI.

[0585] The following describes the upper layer signaling sfnSchemePDCCH and / or sfnSchemePDSCH and the upper layer signaling that determines the presence or absence of a MU-MIMO assist signaling field for DCI format 1_1. sfnSchemePDCCH or sfnSchemePDSCH is information that sets the SFN (single frequency network) method applied to PDCCH or PDSCH. The sfnSchemePDCCH and sfnSchemePDSCH may be upper layer signaling related to the reception of PDCCH and PDSCH transmitted from multiple TRPs using the SFN (single frequency network) method.

[0586] If a terminal is configured by the base station with the upper layer signaling sfnSchemePDCCH and / or sfnSchemePDSCH, the terminal does not need to be configured by the base station with the upper layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1.

[0587] If the base station configures the terminal with the higher layer signaling sfnSchemePDCCH and / or sfnSchemePDSCH, the base station does not need to configure the terminal with the higher layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1.

[0588] If the terminal is configured by the base station with upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1, the terminal does not need to be configured by the base station with the upper-layer signaling sfnSchemePDCCH and / or sfnSchemePDSCH.

[0589] If the base station has configured the terminal with upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1, the base station does not need to configure the terminal with the upper-layer signaling, sfnSchemePDCCH and / or sfnSchemePDSCH.

[0590] The following describes the upper layer signaling searchSpaceLinkingId and the upper layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1. searchSpaceLinkingId is an upper layer signaling that is set for PDCCH repetition transmissions and is set within the upper layer signaling searchSpace. If two searchSpaces have the same searchSpaceLinkingId, the terminal can consider the PDCCHs transmitted based on the two searchSpace settings to be repetition transmissions of each other.

[0591] If a terminal is configured with the upper-layer signaling searchSpaceLinkingId from the base station, the terminal does not need to be configured with the upper-layer signaling from the base station that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1.

[0592] If the base station sets the higher-layer signaling, searchSpaceLinkingId, on the terminal, the base station does not need to set the higher-layer signaling on the terminal that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1.

[0593] If the terminal is configured by the base station with upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1, the terminal does not need to be configured by the base station with the upper-layer signaling, searchSpaceLinkingId.

[0594] If the base station has configured the terminal with upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1, the base station does not need to configure the terminal with the upper-layer signaling, searchSpaceLinkingId.

[0595] The following describes the upper-layer signaling cjtSchemePDSCH, which is related to the feasibility of CJT transmission, and the upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1.

[0596] If a terminal is configured with cjtSchemePDSCH, a higher-layer signaling related to the ability to transmit CJT from the base station, the terminal does not need to be configured with higher-layer signaling from the base station that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1.

[0597] If the base station has configured cjtSchemePDSCH, a higher-layer signaling related to the ability to transmit CJT, on the terminal, the base station does not need to configure a higher-layer signaling on the terminal that determines the presence or absence of a MU-MIMO assist signaling field for DCI format 1_1.

[0598] If a terminal is configured by the base station with upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1, the terminal does not need to be configured by the base station with upper-layer signaling that is related to the ability to transmit CJT, namely cjtSchemePDSCH.

[0599] If the base station has configured the terminal with upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1, the base station does not need to configure the terminal with upper-layer signaling that is related to whether or not CJT transmission is possible, such as cjtSchemePDSCH.

[0600] The following describes the upper layer signaling dl-OrJointTCI-StateList and the upper layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1. If the type of Unified TCI state that can be indicated by the upper layer signaling is separate, dl-OrJointTCI-StateList indicates a DL TCI state, and if the type of Unified TCI state is joint, dl-OrJointTCI-StateList can indicate a joint TCI state for DL ​​and UL operation.

[0601] If a terminal is configured by a base station with a higher-layer signaling dl-OrJointTCI-StateList and is instructed to provide a single joint TCI state in the TCI state field within DCI format 1_1 or 1_2, the terminal can apply that instructed single joint TCI state to receive downlink signals and transmit uplink signals, starting from the first slot that appears after a beam application time, which may be defined as a specific number of OFDM symbols, following a HARQ-ACK transmission indicating whether or not the DCI can be received.

[0602] If a terminal is configured by a base station with a higher-layer signaling dl-OrJointTCI-StateList and is instructed to display one DL TCI state and one UL TCI state in the TCI state field within DCI format 1_1 or 1_2, the terminal can apply the instructed DL TCI state to receive downlink signals, starting from the first slot that appears after a beam application time which may be defined as a specific number of OFDM symbols, following a HARQ-ACK transmission indicating whether the DCI can be received or not, and can apply the instructed UL TCI state to transmit uplink signals.

[0603] If a terminal is configured by a base station with a higher-layer signaling dl-OrJointTCI-StateList and is instructed to provide two joint TCI states in the TCI state field within DCI format 1_1 or 1_2, the terminal can apply those two instructed joint TCI states to receive downlink signals and transmit uplink signals, starting from the first slot that appears after a beam application time that may be defined as a specific number of OFDM symbols, following a HARQ-ACK transmission indicating whether the DCI can be received or not.

[0604] If a terminal is configured by a base station with a higher-layer signaling dl-OrJointTCI-StateList and is instructed to use two DL TCI states and / or two UL TCI states in the TCI state field within DCI format 1_1 or 1_2, the terminal can use the two instructed DL TCI states to receive downlink signals, starting from the first slot that appears after a beam application time which may be defined as a specific number of OFDM symbols, following a HARQ-ACK transmission indicating whether the DCI can be received or not, and the two UL TCI states to transmit uplink signals.

[0605] The above single joint TCI state, DL TCI state, and UL TCI state, or two joint TCI states, DL TCI state, and UL TCI state, may be applied to downlink reception and uplink transmission from a single or multiple TRP, respectively.

[0606] If a terminal is configured by the base station with the upper-layer signaling dl-OrJointTCI-StateList, and the base station is configured with upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1, the terminal does not need to expect the base station to indicate two joint TCI states in the TCI state field within DCI format 1_1 or 1_2, or to indicate two DL TCI states and / or two UL TCI states. (That is, it can expect to indicate one joint TCI state, or one DL TCI state and / or one UL TCI state.)

[0607] If a base station configures the terminal with the upper-layer signaling dl-OrJointTCI-StateList, which determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1, the base station does not need to specify two joint TCI states in the TCI state field within DCI format 1_1 or 1_2, or two DL TCI states and / or two UL TCI states. (That is, it can specify one joint TCI state, or one DL TCI state and / or one UL TCI state.)

[0608] If a terminal is configured with the upper-layer signaling dl-OrJointTCI-StateList by the base station, but not with the upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1, the terminal may expect the base station to indicate two joint TCI states in the TCI state field within DCI format 1_1 or 1_2, or two DL TCI states and / or two UL TCI states. If the base station configures the terminal with the upper-layer signaling dl-OrJointTCI-StateList and also with the upper-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field for DCI format 1_1, the base station may indicate two joint TCI states in the TCI state field within DCI format 1_1 or 1_2, or two DL TCI states and / or two UL TCI states.

[0609] If a terminal is not configured with specific upper-layer signaling from the base station, the terminal can assume that both it and any terminals scheduled with it have the same DMRS power boosting value. If a terminal is not configured with specific upper-layer signaling from the base station, the terminal can assume that both it and any terminals scheduled with it have the same Number of CDM group(s) without data value indicated in the Antenna port field in the DCI. If a terminal is configured with specific upper-layer signaling from the base station, the terminal does not need to assume that both it and any terminals scheduled with it have the same DMRS power boosting value. If a terminal is configured with specific upper-layer signaling from the base station, the terminal does not need to assume that both it and any terminals scheduled with it have the same Number of CDM group(s) without data value indicated in the Antenna port field in the DCI. In the above, specific upper-layer signaling may be referred to as dmrsPowerBoosting as an example, but is not limited to this.

[0610] The terminal can determine whether other terminals scheduled with it in a multi-user MIMO scheme are performing DMRS power boosting, based on whether or not the base station has configured dmrsPowerBoosting, which is a higher-layer signaling method.

[0611] If a terminal is configured with dmrsPowerBoosting by the base station (for example, set to true), the terminal can assume that it and any terminals scheduled with it have the same DMRS power boosting value. That is, the terminal can assume that it and any terminals scheduled with it have the same value for Number of CDM group(s) without data, as indicated in the Antenna port field in the DCI.

[0612] If a terminal is not configured with dmrsPowerBoosting by the base station, or is configured to false, the terminal does not need to assume that both the terminal scheduled with it and the terminal itself have the same DMRS power boosting value. The terminal does not need to assume that the terminal scheduled with it and the terminal itself have the same Number of CDM group(s) without data value indicated in the Antenna port field in the DCI. In other words, the terminal can assume that the terminal scheduled with it and the terminal itself have the same or different Number of CDM group(s) without data values ​​indicated in the Antenna port field in the DCI.

[0613] As yet another example, higher-layer signaling such as dmrsPowerBoosting described above does not need to be defined. In such a case, if a terminal is configured with higher-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field, it can assume that both the terminal scheduled with it and the terminal itself have the same DMRS power boosting value. That is, the terminal can assume that the value of Number of CDM group(s) without data indicated in the Antenna port field in the DCI is the same for both the terminal scheduled with it and the terminal itself. As yet another example, if higher-layer signaling such as dmrsPowerBoosting described above is not defined, the terminal does not need to assume that both the terminal scheduled with it and the terminal itself have the same DMRS power boosting value if higher-layer signaling that determines the presence or absence of the MU-MIMO assist signaling field is configured. That is, the terminal does not need to assume that the value of Number of CDM group(s) without data indicated in the Antenna port field in the DCI is the same for both the terminal scheduled with it and the terminal itself. In other words, a terminal may assume that the terminal scheduled with it and the terminal each have the same or different values ​​for the Number of CDM group(s) without data indicated in the Antenna port field within the DCI.

[0614] If a terminal is not configured with specific upper-layer signaling from the base station, the terminal can assume that it is instructed with time domain resource allocation information that allocates the same time resources to terminals scheduled with it for receiving downlink data (i.e., the terminal can assume that the starting symbol position and symbol length of the resources allocated for downlink data are identical to those of the terminals scheduled with it). If a terminal is configured with specific upper-layer signaling from the base station, the terminal does not need to assume that it is instructed with time domain resource allocation information that allocates the same time resources to terminals scheduled with it (i.e., the terminal does not need to assume that the starting symbol position and / or symbol length of the resources allocated for downlink data are identical to those of the terminals scheduled with it). In the above, specific upper-layer signaling may be referred to as timeDomainResourceAllocationPDSCH or pdsch-timeDomainAllocation as an example, but is not limited thereto.

[0615] If a terminal has not configured specific upper-layer signaling from the base station, the terminal can assume that it is instructed to receive frequency domain resource allocation information that allocates the same frequency resources to terminals scheduled with it for receiving downlink data (i.e., the terminal can assume that the locations of the RBs allocated for downlink data to the terminal and the terminals scheduled with it are identical). If a terminal has configured specific upper-layer signaling from the base station, the terminal does not need to assume that it is instructed to receive frequency domain resource allocation information that allocates the same frequency resources to terminals scheduled with it for receiving downlink data (i.e., the terminal does not need to assume that the locations of the RBs allocated for downlink data to the terminal and the terminals scheduled with it are identical). In this case, the terminal can assume that the PDSCH DMRS of the terminals scheduled with it belong to the same CDM group. Alternatively, the terminal can assume that the PDSCH DMRS of the terminals scheduled with it belong to different CDM groups. In the above, specific upper-layer signaling may be referred to as frequencyDomainResourceAllocation as an example, but is not limited to this.

[0616] If a terminal has not configured specific upper-layer signaling from the base station, the terminal can assume that it and any terminals scheduled with it have the same PRG (precoding resource block group: the precoded RB group, where the DMRS within the PRG are assumed to be precoded with the same precoder) size. If a terminal has not configured specific upper-layer signaling from the base station, the terminal can assume that it and any terminals scheduled with it have the same PRG size. In this case, the terminal can assume that the PDSCH DMRS of the terminals scheduled with it belong to the same CDM group. Alternatively, the terminal can assume that the PDSCH DMRS of the terminals scheduled with it belong to different CDM groups. In the above, specific upper-layer signaling may be referred to as precodingRBGroup as an example, but is not limited to this.

[0617] If a terminal is configured by the base station with a PRG size of 2 or 4 and no specific upper-layer signaling is configured by the base station, the terminal can assume that it will receive frequency resource allocation information to direct the same RB within the same PRG as other terminals scheduled with it. That is, the RBs constituting the same PRG may be the same for the terminal and other terminals scheduled with it. If a terminal is configured by the base station with a PRG size of 2 or 4 and specific upper-layer signaling is configured by the base station, the terminal does not need to assume that it will receive frequency resource allocation information to direct the same RB within the same PRG as other terminals scheduled with it. That is, the RBs constituting the same PRG may be different for the terminal and other terminals scheduled with it. In this case, the terminal can assume that the PDSCH DMRS of other terminals scheduled with it belong to the same CDM group. Alternatively, the terminal can assume that the PDSCH DMRS of other terminals scheduled with it belong to different CDM groups. The specific upper-layer signaling mentioned above can be referred to as precodingAndFreqResourceAllocation as an example, but it is not limited to this.

[0618] A terminal may be configured with specific upper-layer signaling to indicate the highest modulation order among terminals scheduled with it and the MCS table configured for that terminal. In this case, the specific upper-layer signaling may indicate at least one of 64-QAM, 256-QAM, 1024-QAM, or 4096-QAM. If a terminal is not configured with such specific upper-layer signaling, the terminal does not need to assume information about the highest modulation order among terminals scheduled with it and the MCS table configured for that terminal. If a terminal is not configured with such specific upper-layer signaling, the terminal may consider the highest modulation order among terminals scheduled with it and the MCS table configured for that terminal as the specific modulation order, in which case the specific modulation order may be at least one of 64-QAM, 256-QAM, 1024-QAM, or 4096-QAM. The aforementioned specific modulation order may be predetermined. The specific upper-layer signaling described above may be referred to as maxMCS or mcs-Table, but is not limited to these.

[0619] A terminal may be configured by specific upper-layer signaling to provide information regarding whether the MU-MIMO assist signaling field also applies to the improved DMRS type 1 or 2. If a terminal is not configured with improved DMRS type 1 or 2 from the base station and the specific upper-layer signaling is not configured, the terminal can assume that both the terminal scheduled with it and the terminal itself will operate as DMRS type 1 or 2. If a terminal is not configured with improved DMRS type 1 or 2 and the specific upper-layer signaling is configured, the terminal can assume that both the terminal scheduled with it and the terminal itself will operate as DMRS type 1 or 2, or improved DMRS type 1 or 2. That is, the terminal can assume that some of the terminals scheduled with it will operate as DMRS type 1 or 2, and the other some will operate as improved DMRS type 1 or 2.

[0620] If a terminal is configured with enhanced DMRS type 1 or 2 from the base station, the terminal does not need to be configured with the upper-layer signaling corresponding to the MU-MIMO assist signaling field and the specific upper-layer signaling from the base station, or it does not need to be configured with the upper-layer signaling corresponding to the MU-MIMO assist signaling field and the specific upper-layer signaling. In other words, for a terminal configured with enhanced DMRS type 1 or 2, both the MU-MIMO assist signaling field-related settings and the specific upper-layer signaling may be configured, or neither may be configured. Therefore, if a terminal is configured with both the MU-MIMO assist signaling field-related settings and the specific upper-layer signaling, it can be assumed that the terminal and any terminals scheduled with it will operate as DMRS type 1 or 2, or enhanced DMRS type 1 or 2. The specific upper-layer signaling above may be referred to as enhDmrsType as an example, but is not limited to this.

[0621] A terminal can receive a PDSCH considering the above-mentioned factors, depending on whether or not it has been configured by the base station with at least one of the above-mentioned upper-layer signaling (e.g., dmrsPowerBoosting, timeDomainResourceAllocationPDSCH, frequencyDomainResourceAllocation, precodingRBGroup, precodingAndFreqResourceAllocation, maxMCS, enhDmrsType). For example, if a terminal is not configured with dmrsPowerBoosting and timeDomainResourceAllocationPDSCH, the terminal can receive downlink data using at least one of the above-mentioned MU-MIMO methods, assuming that both the terminal and any terminals scheduled with it have been instructed with the same Number of CDM group without data value and the same time resource allocation for receiving downlink data.

[0622] The terminal may configure the above-mentioned upper-layer signaling (e.g., dmrsPowerBoosting, timeDomainResourceAllocationPDSCH, frequencyDomainResourceAllocation, precodingRBGroup, precodingAndFreqResourceAllocation, maxMCS, enhDmrsType) and the upper-layer signaling for the MU-MIMO assist signaling field to be different for each bandwidth portion from the base station. As an example, the above-layer signaling and the upper-layer signaling for the MU-MIMO assist signaling field may be configured within PDSCH-Config for each bandwidth portion. As yet another example, both the above-layer signaling and the upper-layer signaling for the MU-MIMO assist signaling field may be included within an upper-layer signaling such as MU-MIMO-AdvReceiver-Config (parameter names are illustrative and not limited thereto), and MU-MIMO-AdvReceiver-Config may be configured within PDSCH-Config. As yet another example, the upper layer signaling and the upper layer signaling for the MU-MIMO assist signaling field may be configured on a per-cell basis. For example, the upper layer signaling and the upper layer signaling for the MU-MIMO assist signaling field may be configured in ServingCellConfig, respectively, or, similarly to the above, both may be included in an upper layer signaling such as MU-MIMO-AdvReceiver-Config (the parameter names are illustrative and not limited thereto), and MU-MIMO-AdvReceiver-Config may be configured in ServingCellConfig.

[0623] The terminal may be configured by the base station for the above-mentioned upper-layer signaling (e.g., dmrsPowerBoosting, timeDomainResourceAllocationPDSCH, frequencyDomainResourceAllocation, precodingRBGroup, precodingAndFreqResourceAllocation, maxMCS, enhDmrsType) only if the base station has configured it for the upper-layer signaling for the MU-MIMO assist signaling field.

[0624] Figure 16 shows the operation of a terminal according to one embodiment of the present disclosure.

[0625] In step 1600, the terminal can transmit terminal capabilities to the base station. At this time, the reportable terminal capabilities may be at least one combination of the following as defined in the first to fourth embodiments: R-ML receiver-based interference control method during MU-MIMO scheduling, PDSCH256QAM, PDSCH1024QAM, DMRS type, PDSCH mapping type, DCI formats 1_2, 1_3, 4_0, 4_1, 4_2, DMRS sequence, OCC deactivation, maximum number of terminals or maximum number of layers that can be simultaneously scheduled during MU-MIMO scheduling, SPS PDSCH, multi-PDSCH, multi-DCI-based multi-TRP, single-DCI-based multi-TRP, and terminal capabilities associated with C-JT PDSCH scheduling. Step 1600 described above may be omitted.

[0626] In step 1605, the terminal can receive upper-layer signaling from the base station based on the reported terminal capability. At this time, the upper-layer signaling received by the terminal from the base station may be at least one combination of the following defined in the first to fourth embodiments: R-ML receiver-based interference control method during MU-MIMO scheduling, PDSCH256QAM, PDSCH1024QAM, DMRS type, PDSCH mapping type, DCI formats 1_2, 1_3, 4_0, 4_1, 4_2, DMRS sequence, OCC deactivation, maximum number of simultaneously schedulable terminals or maximum number of layers during MU-MIMO scheduling, SPS PDSCH, multi-PDSCH, multi-DCI-based multi-TRP, single-DCI-based multi-TRP, and upper-layer signaling associated with C-JT PDSCH scheduling.

[0627] In step 1610, the terminal can receive a DCI from the base station, which may include a MU-MIMO assist signaling field, and the DCI may correspond to at least one combination of DCI formats 1_0, 1_1, 1_2, 1_3, 4_0, 4_1, and 4_2. While receiving the PDSCH scheduling by the DCI, the terminal can obtain additional information necessary when using an R-ML receiver if the PDSCH scheduling is a MU-MIMO scheduling, as indicated in the MU-MIMO assist signaling field. At this time, the way the terminal parses the MU-MIMO assist signaling field may vary depending on how it is combined with other terminal operations considered in the first to fourth embodiments.

[0628] In step 1615, the terminal can receive a MU-MIMO scheduled PDSCH from the base station, and the terminal can detect its own signal by minimizing interference from other terminals scheduled together using an R-ML receiver, based on additional information obtained from the MU-MIMO assist signaling field included in the DCI.

[0629] The flowchart described above illustrates exemplary methods that can be embodied by the principles of this disclosure, and various modifications are possible to the methods shown in the flowchart disclosed herein. For example, although shown as a series of steps, the various steps in each figure may overlap, occur in parallel, occur in different orders, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.

[0630] Figure 17 shows the operation of a base station according to one embodiment of the present disclosure.

[0631] In step 1700, the base station can receive terminal capabilities from the terminal. At this time, the reportable terminal capabilities may be at least one combination of the following as defined in the first to fourth embodiments: R-ML receiver-based interference control method during MU-MIMO scheduling, PDSCH256QAM, PDSCH1024QAM, DMRS type, PDSCH mapping type, DCI formats 1_2, 1_3, 4_0, 4_1, 4_2, DMRS sequence, OCC deactivation, maximum number of terminals or maximum number of layers that can be simultaneously scheduled during MU-MIMO scheduling, SPS PDSCH, multi-PDSCH, multi-DCI-based multi-TRP, single-DCI-based multi-TRP, and terminal capabilities associated with C-JT PDSCH scheduling. Step 1700 may be omitted.

[0632] In step 1705, the base station can transmit upper layer signaling to the terminal based on the terminal capabilities reported by the terminal. At this time, the base station can define and set upper layer signaling for at least one combination of the following for MU-MIMO scheduling R-ML receiver-based interference control method, PDSCH256QAM, PDSCH1024QAM, DMRS type, PDSCH mapping type, DCI formats 1_2, 1_3, 4_0, 4_1, 4_2, DMRS sequence, OCC deactivation, maximum number of terminals or maximum number of layers that can be simultaneously scheduled during MU-MIMO scheduling, SPS PDSCH, multi-PDSCH, multi-DCI based multi-TRP, single-DCI based multi-TRP, and upper layer signaling associated with C-JT PDSCH scheduling.

[0633] In step 1710, the base station can transmit a DCI to the terminal, which may include a MU-MIMO assist signaling field, and the DCI may correspond to at least one combination of DCI formats 1_0, 1_1, 1_2, 1_3, 4_0, 4_1, and 4_2. While transmitting the PDSCH scheduling by the DCI, the base station can transmit additional information necessary for the terminal to use an R-ML receiver if the PDSCH scheduling is a MU-MIMO scheduling by including the MU-MIMO assist signaling field. At this time, the way the terminal parses the MU-MIMO assist signaling field may vary depending on how it is combined with other terminal operations considered in the first to fourth embodiments.

[0634] In step 1715, the base station can transmit a MU-MIMO scheduled PDSCH to the terminal, and the terminal can detect its signal by minimizing interference from other terminals scheduled together using an R-ML receiver, based on additional information obtained from the MU-MIMO assist signaling field included in the DCI.

[0635] The flowchart described above illustrates exemplary methods that can be embodied by the principles of this disclosure, and various modifications are possible to the methods shown in the flowchart disclosed herein. For example, although shown as a series of steps, the various steps in each figure may overlap, occur in parallel, occur in different orders, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.

[0636] Figure 18 shows the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0637] Referring to Figure 18, the terminal may include a transceiver unit (transceiver) collectively consisting of a terminal receiver unit 1800 and a terminal transmitter unit 1810, memory (not shown), and a terminal processing unit (or terminal control unit or processor) 1805. The transceiver units 1800, 1810, memory, and terminal processing unit 1805 of the terminal can operate according to the terminal communication method described above. However, the components of the terminal are not limited to the example described above. For example, the terminal may include more or fewer components than those described above. The transceiver unit, memory, and processor may also be implemented in the form of a single chip.

[0638] The transmitting / receiving unit can transmit and receive signals with the base station. Here, the signals may include control information and data. For this purpose, the transmitting / receiving unit may consist of an RF transmitter that converts and amplifies the frequency of the transmitted signal, and an RF receiver that low-noise amplified the received signal and converts its frequency down. However, this is only one embodiment of the transmitting / receiving unit, and the components of the transmitting / receiving unit are not limited to an RF transmitter and an RF receiver.

[0639] Furthermore, the transmitting and receiving unit can receive signals via a wireless channel and output them to the processor, and transmit signals output from the processor via the wireless channel.

[0640] Memory can store programs and data necessary for the operation of the terminal. It can also store control information or data contained in signals transmitted and received by the terminal. Memory may consist of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. There may also be multiple memory units.

[0641] Furthermore, the processor can control a series of processes to enable the terminal to operate according to the embodiments described above. For example, the processor can control the terminal's components to receive a DCI consisting of two layers and to receive multiple PDSCHs simultaneously. There may be multiple processors, and the processors can perform terminal component control operations by executing programs stored in memory.

[0642] Figure 19 shows the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0643] Referring to Figure 19, the base station may include a transceiver unit collectively referred to as a base station receiver 1900 and a base station transmitter 1910, a memory (not shown), and a base station processing unit (or base station control unit or processor) 1905. The base station's transceiver units 1900, 1910, memory, and base station processing unit 1905 can operate according to the base station communication method described above. However, the components of the base station are not limited to the example described above. For example, the base station may include more or fewer components than those described above. The transceiver unit, memory, and processor may be implemented in the form of a single chip.

[0644] The transmitting / receiving unit can send and receive signals to and from the terminal. Here, the signal may include control information and data. For this purpose, the transmitting / receiving unit may consist of an RF transmitter that converts and amplifies the frequency of the transmitted signal, and an RF receiver that low-noise amplified the received signal and converts its frequency down. However, this is only one embodiment of the transmitting / receiving unit, and the components of the transmitting / receiving unit are not limited to an RF transmitter and an RF receiver.

[0645] Furthermore, the transmitting and receiving unit can receive signals via a wireless channel and output them to the processor, and transmit signals output from the processor via the wireless channel.

[0646] The memory can store programs and data necessary for the operation of the base station. It can also store control information or data contained in signals transmitted and received by the base station. The memory may consist of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. There may also be multiple memory units.

[0647] The processor can control a series of processes to enable the base station to operate according to the embodiments of the present disclosure described above. For example, the processor can configure a two-layer DCI containing allocation information for multiple PDSCHs and control each component of the base station to transmit it. There may be multiple processors, and the processors can perform base station component control operations by executing programs stored in memory.

[0648] The methods described in the claims or specifications of this disclosure may be embodied in the form of hardware, software, or a combination of hardware and software.

[0649] When embodied in software, a computer-readable storage medium may be provided for storing one or more programs (software modules). The one or more programs stored on the computer-readable storage medium are configured for execution by one or more processors in an electronic device. The one or more programs include instructions that cause the electronic device to perform the method according to the embodiments described in the claims or specification of this disclosure.

[0650] 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 device, compact disc ROM (CD-ROM), digital versatile discs (DVDs), or other forms of optical storage devices, magnetic cassettes, or in memory composed of some or all of these. Furthermore, each constituent memory may include multiple instances.

[0651] Furthermore, the program may be stored in an attachable storage device that can be accessed via a communication network such as the Internet, intranet, LAN (Local Area Network), WLAN (Wide LAN), or SAN (Storage Area Network), or a combination thereof. Such a storage device can be connected to an apparatus performing an embodiment of the disclosure via an external port. Alternatively, a separate storage device on the communication network can be connected to an apparatus performing an embodiment of the disclosure.

[0652] In the specific embodiments of the present disclosure described above, the components included in the invention are expressed singly or plurally in the specific embodiments presented. However, the singly or plural representation is selected for the convenience of explanation and to suit the presented circumstances, and the present disclosure is not limited to singly or plural components. Components expressed plural may consist of a singular component, or components expressed singly may consist of a plural component.

[0653] On the other hand, the embodiments of this disclosure shown in this specification and drawings are merely examples to facilitate the explanation of the technical content of this disclosure and to aid in its understanding, and are not intended to limit the scope of this disclosure. In other words, it will be obvious to a person with ordinary skill in the art to which this disclosure belongs that other modifications based on the technical idea of ​​this disclosure are possible. Furthermore, each of the above embodiments may be combined with each other as needed. For example, a base station and a terminal may be operated by a combination of one embodiment of this disclosure and a part of another embodiment. For example, a base station and a terminal may be operated by a combination of the first embodiment of this disclosure and a part of the second embodiment. Furthermore, although the above embodiments are presented based on an FDD LTE system, other modifications based on the technical idea of ​​the above embodiments may be possible for other systems such as TDD LTE systems, 5G or NR systems.

[0654] On the other hand, in the diagram illustrating the method of the present invention, the order of explanation does not necessarily correspond to the order of execution, and the order of execution may be changed or the methods may be performed in parallel.

[0655] Alternatively, the diagrams illustrating the method of the present invention may omit some components and include only some components, as long as they do not impair the essence of the present invention.

[0656] Furthermore, the methods of the present invention may be implemented by combining some or all of the contents included in each embodiment, to the extent that the essence of the invention is not impaired.

[0657] Various embodiments of the present disclosure have been described above. The above description of the present disclosure is illustrative, and the embodiments of the present disclosure are not limited to those embodiments. A person with ordinary skill in the art to which the present disclosure belongs will understand that the present disclosure can be readily modified into other specific forms without altering the technical idea or essential features of the present disclosure. The scope of the present disclosure is indicated by the attached claims rather than by the above detailed description, and any changes or modifications derived from the meaning and scope of the claims and the concept of equivalents thereto should be interpreted as being included in the scope of the present disclosure.

[0658] Although this disclosure has been described using various embodiments, those skilled in the art can propose various changes and modifications. This disclosure is intended to encompass changes and modifications that fall within the scope of the appended claims.

Claims

1. A method performed by a terminal of a communication system, The process involves receiving configuration information via upper-layer signaling from the base station, indicating that information regarding MU-MIMO (multi-user multi-input and multi-output) is included in DCI (downlink control information), and A step of receiving the DCI for scheduling downlink data from the base station, wherein the DCI includes the information for the MU-MIMO, The step includes receiving the downlink data from the base station based on the information for the MU-MIMO, A method characterized in that a value of 0 for the information for the MU-MIMO indicates that there are no other terminals scheduled together with the terminal, or that other terminals using a different DMRS (demodulation reference signal) sequence than the terminal have been scheduled.

2. The method according to claim 1, characterized in that the upper layer signaling is set for BWP (bandwidth part).

3. The method according to claim 1, characterized in that the DCI corresponds to DCI format 1_1.

4. The method according to claim 1, characterized in that the antenna port information included in the DCI is not related to the two codeword schedulings.

5. A method used by a base station of a communication system, The process involves sending configuration information via upper-layer signaling to the terminal indicating that information regarding MU-MIMO (multi-user multi-input and multi-output) is included in DCI (downlink control information), and A step of transmitting the DCI for scheduling downlink data to the terminal, wherein the DCI includes the information for the MU-MIMO, The step includes transmitting the downlink data to the terminal, A method characterized in that a value of 0 for the information for the MU-MIMO indicates that there are no other terminals scheduled together with the terminal, or that other terminals using a different DMRS (demodulation reference signal) sequence than the terminal have been scheduled.

6. The method according to claim 5, characterized in that the upper layer signaling is set for BWP (bandwidth part).

7. The method according to claim 5, characterized in that the DCI corresponds to DCI format 1_1.

8. The method according to claim 5, characterized in that the antenna port information included in the DCI is not related to the two codeword schedulings.

9. A terminal in a communication system, Transmitter / receiver unit, The base station receives configuration information via upper-layer signaling indicating that information regarding MU-MIMO (multi-user multi-input and multi-output) is included in DCI (downlink control information). The base station receives the DCI for scheduling downlink data, and the DCI includes the information for the MU-MIMO. The set includes a control unit configured to receive the downlink data from the base station based on the information for the MU-MIMO, A terminal characterized in that a value of 0 for the information for the MU-MIMO indicates that there are no other terminals scheduled together with the terminal, or that other terminals using a different DMRS (demodulation reference signal) sequence than the terminal have been scheduled.

10. The terminal according to claim 9, characterized in that the upper layer signaling is configured for BWP (bandwidth part).

11. The terminal according to claim 9, characterized in that the DCI corresponds to DCI format 1_1.

12. The terminal according to claim 9, characterized in that the antenna port information included in the DCI is not related to the two codeword schedulings.

13. A base station in a communication system, Transmitter / receiver unit, The terminal receives configuration information via upper-layer signaling indicating that information regarding MU-MIMO (multi-user multi-input and multi-output) is included in DCI (downlink control information). The DCI for scheduling downlink data is transmitted to the terminal, and the DCI includes the information for the MU-MIMO. The set includes a control unit configured to transmit the downlink data to the terminal, A base station characterized in that the value of 0 for the information for the MU-MIMO indicates that there are no other terminals scheduled together with the terminal, or that other terminals using a different DMRS (demodulation reference signal) sequence than the terminal have been scheduled.

14. The base station according to claim 13, characterized in that the upper layer signaling is configured for BWP (bandwidth part).

15. The aforementioned DCI corresponds to DCI format 1_1, The base station according to claim 13, characterized in that the antenna port information included in the DCI is not related to the two codeword schedulings.

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