Method and device for transmitting control information for MU-MIMO in wireless communication system

Abstract

Disclosed is a method and a device, the method comprising the steps of: receiving MU-MIMO-related MU DCI; receiving DCI for a terminal; and receiving a downlink data channel on the basis of the MU DCI and the DCI for the terminal, wherein the MU DCI is transmitted to a group including at least one terminal at the same time and through the same frequency resource.

Description

Method and device for transmitting control information for MU-MIMO in a wireless communication system

[0001] The present invention relates to control information for multi-user multi-input multi-output (MU-MIMO) in a wireless communication system. More specifically, the present invention relates to a method or device for efficiently utilizing resources by grouping multiple terminals.

[0002] Looking back at the evolution of wireless communication over successive generations, technologies have primarily been developed for human-facing services such as voice, multimedia, and data. With the commercialization of 5G (5th-generation) communication systems, an explosive increase in connected devices is expected to be connected to communication networks. Examples of networked objects include vehicles, robots, drones, home appliances, displays, smart sensors installed in various infrastructures, construction equipment, and factory equipment. Mobile devices are also expected to evolve into diverse form factors, such as augmented reality glasses, virtual reality headsets, and holographic devices. In the 6th-generation (6G) era, efforts are being made to develop improved 6G communication systems to connect hundreds of billions of devices and objects and provide diverse services. For this reason, 6G communication systems are often referred to as "beyond 5G" systems.

[0003] The 6G communication system, expected to be realized around 2030, will have a maximum transmission speed of terabytes per second (i.e., 1,000 gigabits per second) and a wireless latency of 100 microseconds (μsec). In other words, compared to 5G, the transmission speed in a 6G communication system will be 50 times faster, while the wireless latency will be reduced to one-tenth.

[0004] To achieve these high data rates and ultra-low latency, 6G communication systems are being considered for implementation in the terahertz band (e.g., from 95 gigahertz (GHz) to 3 terahertz (THz)). Compared to the millimeter wave (mmWave) band introduced in 5G, the terahertz band is expected to experience more severe path loss and atmospheric absorption, making it more crucial to ensure signal reach, or coverage, in this band. Key technologies to ensure coverage include radio frequency (RF) components, antennas, new waveforms that offer better coverage than OFDM (orthogonal frequency division multiplexing), beamforming, and multiple antenna transmission technologies such as massive multiple-input and multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas. In addition, new technologies such as metamaterial-based lenses and antennas, high-dimensional spatial multiplexing using orbital angular momentum (OAM), and reconfigurable intelligent surfaces (RIS) are being discussed to improve the coverage of terahertz band signals.

[0005] In addition, in order to improve frequency efficiency and system network, 6G communication systems are developing full duplex technology that utilizes the same frequency resources for uplink and downlink at the same time; network technology that integrates satellites and high-altitude platform stations (HAPS); network structure innovation technology that supports mobile base stations and enables optimization and automation of network operation; dynamic spectrum sharing technology through collision avoidance based on spectrum usage prediction; AI-based communication technology that utilizes artificial intelligence (AI) from the design stage and internalizes end-to-end AI support functions to realize system optimization; and next-generation distributed computing technology that realizes services with complexity that exceeds the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources (mobile edge computing (MEC), cloud, etc.). In addition, efforts are being made to further strengthen connectivity between devices, further optimize networks, promote softwareization of network entities, and increase the openness of wireless communications through the design of new protocols to be used in 6G communication systems, the implementation of hardware-based security environments, the development of mechanisms for the safe use of data, and the development of technologies for maintaining privacy.

[0006] Research and development of these 6G communication systems are expected to enable a new level of hyper-connected experience (the next hyper-connected experience) through the hyper-connectivity of 6G communication systems, which encompass not only connections between things but also connections between people and things. Specifically, 6G communication systems are expected to enable services such as truly immersive extended reality (Truly Immersive XR), high-fidelity mobile holograms, and digital replicas. Furthermore, services such as remote surgery, industrial automation, and emergency response, which are provided through 6G communication systems through enhanced security and reliability, will find application in diverse fields such as industry, medicine, automobiles, and home appliances.

[0007] To fully utilize the benefits of MU-MIMO (multi-user multiple input multiple output) technology, a resource allocation method or device for efficient control information transmission is required. Specifically, when scheduling MU-MIMO transmission, although many layers can be utilized, if there are insufficient resources to transmit control information (e.g., DCI, etc.), not all DCI can be transmitted to terminals or more symbols are required, this can lead to a decrease in data channel efficiency due to inefficiency in the control channel. Therefore, a resource allocation method or device to address this issue is required.

[0008] The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0009] The present disclosure, for solving the above problems, is a method performed by a terminal of a wireless communication system, comprising: receiving, from a base station, MU (multi-user) DCI (downlink control information) related to MU-MIMO (multi-user multiple input multiple output); receiving, from the base station, DCI for the terminal; and receiving, from the base station, a downlink data channel based on at least one of the MU DCI or the DCI for the terminal, wherein the MU DCI includes information to be transmitted to a group including at least one terminal through the same time and same frequency resource.

[0010] In addition, it is characterized by including a step of receiving a first message for receiving the MU DCI from the base station.

[0011] Additionally, the first message is characterized in that it includes at least one of information about a search space for MU DCI reception or information about a radio network temporary identifier (RNTI).

[0012] In addition, it is characterized by including a step of receiving a second message for changing information for receiving the MU DCI from the base station.

[0013] In addition, the MU DCI is characterized in that it includes information for receiving DCI for the terminal.

[0014] In addition, the information for receiving DCI for the terminal is characterized in that it includes at least one of information related to an allocation location of DCI for the terminal or information on an aggregation level (AL).

[0015] The present disclosure, for solving the above problems, is a method performed by a base station of a wireless communication system, comprising: transmitting, to a terminal, MU (multi-user) DCI (downlink control information) related to MU-MIMO (multi-user multiple input multiple output); transmitting, to the terminal, DCI for the terminal; and transmitting, to the terminal, a downlink data channel, wherein the MU DCI includes information to be transmitted to a group including at least one terminal through the same time and same frequency resource.

[0016] In order to solve the above problems, the present disclosure provides a terminal of a wireless communication system, comprising: a transceiver; and a control unit connected to the transceiver, configured to receive, from a base station, MU (multi-user) DCI (downlink control information) related to MU-MIMO (multi-user multiple input multiple output), receive DCI for the terminal from the base station, and receive, from the base station, a downlink data channel based on at least one of the MU DCI or the DCI for the terminal, wherein the MU DCI includes information to be transmitted to a group including at least one terminal through the same time and same frequency resource.

[0017] The present disclosure, for solving the above problems, is a base station of a wireless communication system, comprising: a transceiver; and a control unit connected to the transceiver, for transmitting MU (multi-user) DCI (downlink control information) related to MU-MIMO (multi-user multiple input multiple output) to a terminal, transmitting DCI for the terminal to the terminal, and transmitting a downlink data channel to the terminal, wherein the MU DCI includes information to be transmitted to a group including at least one terminal through the same time and same frequency resource.

[0018] One embodiment of the present disclosure can effectively utilize resources by transmitting common control information (e.g., DCI, etc.) for each terminal group in a MU-MIMO (multi-user multiple input multiple output) environment.

[0019] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

[0020] FIG. 1 is a diagram illustrating the basic structure of a time-frequency domain, which is a radio resource domain in which data or control channels are transmitted, according to one embodiment of the present disclosure.

[0021] FIG. 2 is a diagram illustrating a PDCCH, which is a downlink physical channel through which DCI is transmitted, according to one embodiment of the present disclosure.

[0022] FIG. 3 is a diagram illustrating a basic unit of time and frequency resources constituting a downlink control channel according to an embodiment of the present disclosure.

[0023] FIG. 4 is a diagram illustrating a control resource set in which a downlink control channel is transmitted according to an embodiment of the present disclosure.

[0024] FIG. 5 is a diagram illustrating a configuration for a downlink RB structure according to an embodiment of the present disclosure.

[0025] FIG. 6 is a diagram illustrating a process between a base station and a terminal when the base station has downlink data to transmit to a specific terminal according to one embodiment of the present disclosure.

[0026] FIG. 7 is a diagram illustrating a communication system performing MU-MIMO transmission according to one embodiment of the present disclosure.

[0027] FIG. 8 is a diagram illustrating a DCI transmission process for transmitting scheduling information for performing MU-MIMO transmission according to one embodiment of the present disclosure.

[0028] FIG. 9 is a diagram illustrating DCI transmission via PDCCH in relation to MU-MIMO according to one embodiment of the present disclosure.

[0029] FIG. 10 is a diagram illustrating a base station and terminal signaling process according to one embodiment of the present disclosure.

[0030] FIG. 11 is a diagram illustrating a base station and terminal signaling process according to one embodiment of the present disclosure.

[0031] FIG. 12 illustrates a method for setting up multiple groups or sets in relation to MU-MIMO, according to one embodiment of the present disclosure.

[0032] FIG. 13 illustrates an example of a form in which DCI is transmitted to each set or terminal through a PDCCH in an MU-MIMO environment according to one embodiment of the present disclosure.

[0033] FIG. 14a and FIG. 14b illustrate that setting information is transmitted differently to each terminal as different information is set in each set according to one embodiment of the present disclosure.

[0034] FIG. 15 illustrates a process for changing setting information set for terminals in a specific set according to one embodiment of the present disclosure.

[0035] FIG. 16 illustrates a process of a specific terminal changing a set in relation to MU-MIMO according to one embodiment of the present disclosure.

[0036] FIG. 17 illustrates a method for improving the efficiency of a blind decoding process of a terminal in performing a method of allocating common control channel resources to terminals belonging to a candidate group of scheduling related to MU-MIMO or terminals belonging to each set, according to one embodiment of the present disclosure.

[0037] FIG. 18 is a drawing showing an example of a terminal structure according to one embodiment of the present disclosure.

[0038] FIG. 19 is a drawing showing an example of the structure of a base station according to one embodiment of the present disclosure.

[0039] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0040] In describing the embodiments, descriptions of technical contents that are well known in the technical field to which the present disclosure belongs and are not directly related to the present disclosure are omitted.

[0041] This is to convey the gist of the present disclosure more clearly without obscuring it by omitting unnecessary explanations.

[0042] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0043] The advantages and features of the present disclosure and the methods for achieving them will become apparent with reference to the embodiments described in detail below together with the accompanying drawings.

[0044] However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to complete the composition of the present disclosure and to fully inform those skilled in the art of the disclosure of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

[0045] At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can be directed to a computer or other programmable data processing equipment for implementation in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions can also be installed on a computer or other programmable data processing device, a series of operational steps can be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) can also provide steps for performing the functions described in the flowchart block(s).

[0046] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0047] Here, the term '~ unit' used in the present embodiment means software or hardware components such as FPGA (field programmable gate array) or ASIC (application-specific integrated circuit), and the '~ unit' performs certain roles. However, the '~ unit' is not limited to software or hardware. The '~ unit' may be configured to be on an addressable storage medium, and may be configured to play one or more processors. Accordingly, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ units' may be combined into a smaller number of components and '~ units', or further separated into additional components and '~ units'. Additionally, the components and '~parts' may be implemented to play one or more central processing units (CPUs) within the device or secure multimedia card.

[0048] For the convenience of the following description, some terms and names defined in the 3rd generation partnership project (3GPP) standards (standards for 5G, NR, LTE, or similar systems) may be used. In addition, terms and names newly defined in next-generation communication systems (e.g., 6G, Beyond 5G systems) to which the present disclosure may be applied, or terms and names used in existing communication systems may be used. The use of such terms is not limited to the terms and names of the present disclosure, and may be equally applied to systems conforming to other standards, and may be modified into other forms without departing from the technical spirit of the present disclosure. Embodiments of the present disclosure may be easily modified and applied to other communication systems.

[0049] Additionally, it will be understood that singular expressions such as “a” and “the above” include plural expressions unless they clearly indicate otherwise in one embodiment of the present disclosure.

[0050] Additionally, in one embodiment of the present disclosure, terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present disclosure, a first component could be referred to as a second component, and similarly, a second component could also be referred to as a first component.

[0051] Additionally, in one embodiment of the present disclosure, the term “and / or” includes a combination of a plurality of related described items or any one of a plurality of related described items.

[0052] In addition, the terms used in the embodiments of the present disclosure are only used to describe specific embodiments and are not intended to limit the present disclosure. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, it should be understood that the terms "comprise" or "have" are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0053] Additionally, the terms “associated with” and “associated therewith” and their derivatives used in one embodiment of the present disclosure may mean include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicated with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, and the like.

[0054] Additionally, in the present disclosure, expressions such as "more than" and "less than" are used to determine whether a specific condition is satisfied or fulfilled. However, this is merely a description to express an example and does not exclude descriptions of more than or less than. Conditions described as "more than" may be replaced with "more than," conditions described as "less than" may be replaced with "less than," and conditions described as "more than and less than" may be replaced with "more than and less than."

[0055] Additionally, although the present disclosure describes embodiments using terms used in certain communication standards (e.g., long term evolution (LTE) and new radio (NR) defined by the 3rd generation partnership project (3GPP)), these are merely examples for illustrative purposes. The embodiments of the present disclosure can be easily modified and applied to other communication systems.

[0056] Before delving into the detailed description of this disclosure, examples of possible interpretations of some terms used herein are provided. However, it should be noted that the interpretations provided below are not limited to these examples.

[0057] In the present disclosure, a terminal (or communication terminal) is an entity that communicates with a base station or another terminal, and may be referred to as a node, UE (user equipment), NG UE (next generation UE), MS (mobile station), device, or terminal. In addition, the terminal may include at least one of a smartphone, a tablet PC, a mobile phone, a video phone, an e-book reader, a desktop PC, a laptop PC, a netbook computer, a PDA, a PMP (portable multimedia player), an MP3 player, a medical device, a camera, or a wearable device. In addition, the terminal may include at least one of a television, a DVD (digital video disk) player, an audio player, a refrigerator, an air conditioner, a vacuum cleaner, an oven, a microwave oven, a washing machine, an air purifier, a set-top box, a home automation control panel, a security control panel, a media box, a game console, an electronic dictionary, an electronic key, a camcorder, or an electronic picture frame.In addition, the terminal may include at least one of various medical devices (e.g., various portable medical measuring devices (such as blood glucose meters, heart rate monitors, blood pressure monitors, or body temperature monitors), magnetic resonance angiography (MRA), magnetic resonance imaging (MRI), computed tomography (CT), cameras, or ultrasound machines), navigation devices, global navigation satellite systems (GNSS), event data recorders (EDR), flight data recorders (FDR), automotive infotainment devices, electronic equipment for ships (e.g., navigation devices for ships, gyrocompasses, etc.), avionics, security devices, head units for vehicles, industrial or home robots, drones, ATMs for financial institutions, POSs (points of sales) for stores, or Internet of Things devices (e.g., light bulbs, various sensors, sprinkler devices, fire alarms, thermostats, streetlights, toasters, exercise equipment, hot water tanks, heaters, boilers, etc.). Additionally, the terminal may include various types of multimedia systems capable of performing communication functions. Meanwhile, the present disclosure is not limited to the above description, and the terminal may also be referred to by terms having the same or similar meaning.

[0058] In addition, in the present disclosure, the base station is an entity that communicates with a terminal and performs resource allocation of the terminal, and may have various forms and may be referred to as a BS (base station), a NodeB (NB), an NG RAN (next generation radio access network), an AP (access point), a TRP (transmission reception point), a wireless access unit, a base station controller, or a node on a network. Alternatively, it may be referred to as a CU (central unit) or a DU (distributed unit) depending on functional separation. Meanwhile, the present disclosure is not limited thereto, and the base station may be referred to by a term having the same or similar meaning.

[0059] Additionally, in the present disclosure, an RRC (radio resource control) message may be referred to as a higher level information, a higher level message, a higher level signal, a higher level signaling, a higher layer signaling, or a higher layer signaling, and the present disclosure is not limited thereto and may also be referred to by terms having the same or similar meaning.

[0060] Additionally, in the present disclosure, data may be referred to as user data, user plane (UP) data, or application data, or may be referred to by terms having the same or similar meaning as signals transmitted and received via a data radio bearer (DRB).

[0061] Additionally, in the present disclosure, the direction of data transmitted from a terminal may be referred to as uplink (UL), and the direction of data transmitted to the terminal may be referred to as downlink (DL). Accordingly, in the case of uplink transmission, the transmitter may refer to the terminal, and the receiver may refer to a base station or a specific network entity of the communication system. Alternatively, in the case of downlink transmission, the transmitter may refer to a base station or a specific network entity of the communication system, and the receiver may refer to the terminal.

[0062] FIG. 1 is a diagram illustrating the basic structure of a time-frequency domain, which is a radio resource domain in which data or control channels are transmitted, according to one embodiment of the present disclosure.

[0063] In Fig. 1, the horizontal axis can represent the time domain, and the vertical axis can represent the frequency domain, and can represent the basic structure of the time-frequency domain in the LTE system. The minimum transmission unit in the time domain is an OFDM symbol (101), and N symb OFDM symbols (101) may be grouped to form one slot (102), and two slots may be grouped to form one subframe (103). The length of the slot (102) may be 0.5 ms, and the length of the subframe (103) may be exemplified as 1.0 ms. In addition, a radio frame (104) may correspond to a time domain unit composed of 10 subframes (103). The minimum transmission unit in the frequency domain is a subcarrier (105), and the bandwidth of the entire system transmission bandwidth is a total of N BW It can be composed of a subcarrier (105).

[0064] The basic unit of resources in the time-frequency domain is a resource element (RE) (106), which can be represented by an OFDM symbol index and a subcarrier index. A resource block (RB; Resource Block or PRB; Physical Resource Block) (107) is N in the time domain. symb N consecutive OFDM symbols (101) in the frequency domain RB can be defined as a series of consecutive subcarriers (108). Therefore, one RB (107) is N symb x N RB It can be composed of RE(106). The minimum transmission unit of data can correspond to the RB unit. For example, in LTE system, generally the N symb = 7, N RB =12, and N BW and N RB can be proportional to the bandwidth of the system transmission band.

[0065] Next, we will specifically explain downlink control information (DCI) in LTE and LTE-A systems.

[0066] In an LTE system, scheduling information for downlink or uplink data can be transmitted from a base station to a terminal via DCI. The DCI can include information such as whether the DCI is scheduling information for uplink or downlink data, whether it is compact DCI with small control information size, whether it applies spatial multiplexing using multiple antennas, and whether it is DCI for power control. Furthermore, a DCI format defined according to the above-described information can be applied and operated. For example, DCI format 1, which is scheduling control information for downlink data, can be configured to include at least the following control information.

[0067] - Resource allocation type 0 / 1 flag: It can notify whether the resource allocation method is type 0 or type 1. Type 0 can allocate resources in units of RBG (resource block group) by applying a bitmap method. In the LTE system, the basic unit of scheduling is an RB (resource block) expressed as a time and frequency domain resource, and an RBG is composed of multiple RBs and can be the basic unit of scheduling in the type 0 method. Type 1 can allocate a specific RB within an RBG.

[0068] Resource block assignment: Notifies the RBs allocated for data transmission. The resources represented can be determined based on system bandwidth and resource allocation method.

[0069] - Modulation and Coding Scheme (MCS): It can notify the modulation method used for data transmission and the size of the transport block, which is the data to be transmitted.

[0070] - HARQ process number: The HARQ process number can be notified.

[0071] - New data indicator: Can notify whether it is a HARQ initial transmission or a retransmission.

[0072] - Redundancy version: The redundancy version of HARQ can be notified.

[0073] - Transmit Power Control command for PUCCH (Physical Uplink Control CHannel) (TPC): A transmit power control command for PUCCH, which is an uplink control channel, can be notified.

[0074] The above DCI can be transmitted through a downlink physical control channel, PDCCH (Physical Downlink Control CHannel), after going through a channel coding and modulation process.

[0075] The DCI message payload is accompanied by a CRC (Cyclic Redundancy Check), which can be scrambled with an RNTI (Radio Network Temporary Identifier) ​​corresponding to the identity of the UE. Different RNTIs can be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control command, or random access response. In other words, the RNTI can be included in the CRC calculation process rather than being transmitted explicitly. When a DCI message transmitted on the PDCCH is received, the UE verifies the CRC using the assigned RNTI. If the CRC verification result is correct, it can be determined that the message was transmitted to that UE.

[0076] FIG. 2 is a diagram illustrating a PDCCH, which is a downlink physical channel through which DCI is transmitted, according to one embodiment of the present disclosure.

[0077] According to FIG. 2, PDCCH (201) is time-multiplexed with PDSCH (Physical Downlink Shared Channel) (202), which is a data transmission channel, and can be transmitted across the entire system bandwidth, and can be exemplified by PDCCH (201) of LTE. The area of ​​PDCCH (201) is expressed by the number of OFDM symbols, and this can be indicated to the terminal by CFI (Control Format Indicator) transmitted through PCFICH (Physical Control Format Indicator CHannel).

[0078] By allocating PDCCH (201) to the OFDM symbol at the beginning of the subframe, the terminal can decode the downlink scheduling assignment as quickly as possible, thereby reducing the decoding delay for the DL-SCH (Downlink Shared CHannel), i.e., the overall downlink transmission delay.

[0079] A single PDCCH carries a single DCI message, and since multiple terminals can be scheduled simultaneously on downlink and uplink, multiple PDCCH transmissions can occur simultaneously within each cell. A cell-specific reference signal (CRS) (203) can be used as a reference signal for decoding the PDCCH (201). The CRS (203) is transmitted in every subframe across the entire bandwidth, and scrambling and resource mapping can vary depending on the cell ID (IDentity). Since the CRS (203) is a reference signal commonly used by all terminals, terminal-specific beamforming cannot be used. Therefore, the multi-antenna transmission method for the PDCCH of LTE can be limited to open-loop transmit diversity. The number of ports of the CRS can be implicitly known to the terminal through the decoding of the PBCH (Physical Broadcast CHannel).

[0080] Resource allocation of the PDCCH (201) is based on Control-Channel Elements (CCEs), and one CCE can be composed of nine Resource Element Groups (REGs), i.e., a total of 36 Resource Elements (REs). The number of CCEs required for a specific PDCCH (201) can be 1, 2, 4, or 8, and this number can vary depending on the channel coding rate of the DCI message payload. In this way, different numbers of CCEs can be used to implement link adaptation of the PDCCH (201).

[0081] The terminal must detect a signal without knowing information about the PDCCH (201). In LTE, a search space representing a set of CCEs can be defined for blind decoding. The search space consists of multiple sets at the aggregation level (AL) of each CCE, and this can be implicitly defined through a function based on the terminal identity and subframe number without being explicitly signaled. Within each subframe, the terminal performs decoding on the PDCCH (201) for all possible resource candidates that can be created from the CCEs within the configured search space, and processes information declared valid for the terminal through CRC verification.

[0082] Search spaces can be categorized into terminal-specific search spaces and common search spaces. A certain group of terminals or all terminals can search the common search space of the PDCCH (201) to receive cell-common control information, such as dynamic scheduling or paging messages for system information. For example, scheduling allocation information for the DL-SCH for transmission of the SIB (System Information Block)-1, which includes cell operator information, can be received by searching the common search space of the PDCCH (201).

[0083] In LTE, the entire PDCCH region is composed of a set of CCEs in the logical domain, and a search space consisting of these CCEs can exist. The search space is divided into a common search space and a terminal-specific search space. The search space for the LTE PDCCH can be defined as follows.

[0084]

[0085] According to the definition of search space for the PDCCH described above, a terminal-specific search space can be implicitly defined through a function based on terminal identity and subframe number without being explicitly signaled. In other words, since the terminal-specific search space can change based on the subframe number, this implies that it can change over time, thereby resolving the problem of a specific terminal being blocked from using the search space by other terminals (blocking problem).

[0086] In one embodiment, if a particular terminal is not scheduled in a subframe because all the CCEs it is searching for are already being used by other terminals scheduled in the same subframe, this problem may not occur in the next subframe because this search space changes over time. For example, even if a portion of the terminal-specific search spaces of terminal #1 and terminal #2 overlap in a particular subframe, the overlap in the next subframe can be expected to be different because the terminal-specific search space changes from subframe to subframe.

[0087] According to the definition of the search space for the PDCCH described above, the common search space can be defined as a pre-arranged set of CCEs, since a certain group of terminals or all terminals must receive the PDCCH. In other words, the common search space may not change based on terminal identity or subframe number. Although the common search space exists for the transmission of various system messages, it can also be used to transmit control information for individual terminals. This allows the common search space to be used as a solution to the phenomenon of terminals not being scheduled due to insufficient resources in the terminal-specific search space.

[0088] A search space is a set of candidate control channels, consisting of CCEs, that a UE must attempt to decode at a given aggregation level. Since there are multiple aggregation levels, each of which creates a single bundle of 1, 2, 4, or 8 CCEs, a UE can have multiple search spaces. The number of PDCCH candidates that a UE must monitor within a search space defined by the aggregation level in the LTE PDCCH can be defined as shown in the table below.

[0089] [Table 1]

[0090]

[0091] According to [Table 1], in the case of the terminal-specific search space, aggregation levels {1, 2, 4, 8} are supported, and in this case, {6, 6, 2, 2} PDCCH candidates can be had. In the case of the common search space, aggregation levels {4, 8} are supported, and in this case, {4, 2} PDCCH candidates can be had. The reason why the common search space supports only aggregation levels {4, 8} may be to improve coverage characteristics, since system messages generally have to reach the cell edge.

[0092] DCI transmitted in the common search space can only be defined for specific DCI formats, such as 0 / 1A / 3 / 3A / 1C, which correspond to system messages or power control for a group of terminals. DCI formats with spatial multiplexing may not be supported within the common search space. The downlink DCI format to be decoded in the terminal-specific search space may vary depending on the transmission mode configured for the terminal. Since the transmission mode is configured via RRC (Radio Resource Control) signaling, the exact subframe number that determines whether the configuration takes effect for the terminal may not be specified. Therefore, the terminal can operate without losing communication by always performing decoding for DCI format 1A regardless of the transmission mode.

[0093] The above may be an example of a method for transmitting and receiving downlink control channels and downlink control information in conventional LTE and LTE-A, and a search space.

[0094] Below, an example of a downlink control channel in the 5G communication system currently being discussed will be described in more detail with reference to drawings.

[0095] FIG. 3 is a diagram illustrating a basic unit of time and frequency resources constituting a downlink control channel according to an embodiment of the present disclosure.

[0096] According to FIG. 3, the REG (Resource Element Group) (303), which is the basic unit of time and frequency resources constituting the control channel, is composed of 1 OFDM symbol (301) on the time axis and 12 subcarriers (302) on the frequency axis, that is, 1 RB (Resource Block), and may correspond to an example of the basic unit of time and frequency resources in 5G. By assuming that the basic unit of the time axis is 1 OFDM symbol (301) in constituting the basic unit of the control channel, the data channel and the control channel can be time multiplexed within one subframe. By positioning the control channel before the data channel, the processing time of the user can be reduced, which can make it easy to satisfy the delay time requirement. By setting the basic unit of the frequency axis of the control channel to 1 RB (302), frequency multiplexing between the control channel and the data channel can be performed more efficiently.

[0097] By concatenating REGs (303) illustrated in FIG. 3, control channel areas of various sizes can be set. For example, if the basic unit to which a downlink control channel is allocated in 5G is called a Control Channel Element (CCE) (304), 1 CCE (304) can be composed of multiple REGs (303). Taking REG (303) illustrated in FIG. 3 as an example, if REG (303) can be composed of 12 REs and 1 CCE (304) is composed of 6 REGs (303), it can mean that 1 CCE (304) can be composed of 72 REs. When a downlink control area is set, the area can be composed of multiple CCEs (304), and a specific downlink control channel can be mapped to one or multiple CCEs (304) and transmitted according to the aggregation level (AL) within the control area. CCEs (304) within the control area are distinguished by numbers, and the numbers can be assigned according to a logical mapping method.

[0098] The basic unit of the downlink control channel illustrated in FIG. 3, that is, the REG (303), may include both REs to which DCI is mapped and REs to which a DMRS (Demodulation Reference Signal) (305), which is a reference signal for decoding the same, is mapped. As shown in FIG. 3, the DMRS (305) may be transmitted in three REs within one REG (303). For reference, since the DMRS (305) is transmitted using the same precoding as the control signal mapped within the REG (303), the terminal can decode the control information even without information on what precoding the base station applied.

[0099] FIG. 4 is a diagram illustrating a control resource set in which a downlink control channel is transmitted according to an embodiment of the present disclosure.

[0100] An example of Fig. 4 may assume that 1 slot is 7 OFDM symbols, and may correspond to an example of CORESET in a 5G wireless communication system. Fig. 4 illustrates that two control regions (Control Region #1 (401), Control Region #2 (402)) are set within a system bandwidth (410) in the frequency axis and 1 slot (420) in the time axis. The frequency of the control regions (401, 402) may be set to a specific subband (403) within the entire system bandwidth (410). The time length of the control regions (401, 402) may be set to one or more OFDM symbols, and further, the time length of the control regions (401, 402) may be defined as a control region length (Control Resource Set Duration) (404). In an example of FIG. 4, control area #1 (401) is set to a control area length of 2 symbols, and control area #2 (402) is set to a control area length of 1 symbol.

[0101] The control region in 5G, as described above, can be established by the base station to the terminal via higher-layer signaling (e.g., system information, Master Information Block (MIB), RRC signaling). Establishing a control region for the terminal means providing information such as the control region's location, subbands, control region resource allocation, and control region length. For example, this information may include the information in [Table 2].

[0102] [Table 2]

[0103]

[0104] The configuration information in [Table 2] is an example of the present disclosure, and in addition to the configuration information in [Table 2], various pieces of information required for transmitting a downlink control channel can be set in the terminal.

[0105] Next, we will explain downlink control information (DCI) in detail.

[0106] In a 5G system, scheduling information for uplink data (PUSCH; Physical Uplink Shared CHannel) or downlink data (PDSCH; Physical Downlink Shared CHannel) can be transmitted from the base station to the terminal via DCI.

[0107] A terminal can monitor a fallback DCI format and a non-fallback DCI format for PUSCH or PDSCH. The fallback DCI format may consist of fixed fields between the base station and the terminal, and the non-fallback DCI format may include configurable fields.

[0108] According to one embodiment of the present disclosure, a DCI for scheduling a PUSCH may include information of [Table 3].

[0109] [Table 3]

[0110]

[0111] According to one embodiment of the present disclosure, DCI for non-contingent scheduling of PUSCH may include information of [Table 4].

[0112] [Table 4]

[0113]

[0114]

[0115] According to one embodiment of the present disclosure, a DCI for scheduling a PDSCH may include information of [Table 5].

[0116] [Table 5]

[0117]

[0118] According to one embodiment of the present disclosure, a DCI for non-contingent scheduling of PDSCH may include information of [Table 6].

[0119] [Table 6]

[0120]

[0121] The above DCI can be transmitted through the PDCCH (Physical Downlink Control CHannel) after going through the channel coding and modulation process. The DCI message payload includes a CRC (Cyclic Redundancy Check), and the CRC can be scrambled with an RNTI (Radio Network Temporary Identifier), which corresponds to the terminal's identity.

[0122] Different RNTIs can be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control commands, or random access responses. In other words, the RNTI may not be explicitly transmitted, but rather included in the CRC calculation process. When a UE receives a DCI message transmitted on the PDCCH, it can verify the CRC using the assigned RNTI. If the CRC verification result is correct, the UE can determine that the message was sent to that UE.

[0123] For example, a DCI scheduling a PDSCH for system information (SI) may be scrambled with SI-RNTI. A DCI scheduling a PDSCH for a Random Access Response (RAR) message may be scrambled with RA-RNTI. A DCI scheduling a PDSCH for a paging message may be scrambled with P-RNTI. A DCI notifying a Slot Format Indicator (SFI) may be scrambled with SFI-RNTI. A DCI notifying a Transmit Power Control (TPC) may be scrambled with TPC-RNTI. A DCI scheduling a UE-specific PDSCH or PUSCH may be scrambled with C-RNTI (Cell RNTI).

[0124] When a specific terminal is scheduled for a data channel, i.e., PUSCH or PDSCH, through the PDCCH, data can be transmitted and received together with DMRS within the scheduled resource region.

[0125] FIG. 5 is a diagram illustrating a configuration for a downlink RB structure according to an embodiment of the present disclosure.

[0126] Fig. 5 may represent a case where a specific terminal uses 14 OFDM symbols as one slot (or subframe) in downlink, PDCCH is transmitted in the first two OFDM symbols, and DMRS is transmitted in the third symbol, which may correspond to an example of a configuration for an RB structure in 5G. In the case of Fig. 5, within a specific RB where a PDSCH is scheduled, the PDSCH may be transmitted by mapping data to REs where DMRS is not transmitted in the third symbol and REs from the fourth to the last symbol thereafter. The subcarrier spacing expressed in Fig. 5 f is 15 kHz for LTE / LTE-A systems and one of {15, 30, 60, 120, 240, 480} kHz can be used for 5G systems.

[0127] Meanwhile, as described above, a base station can transmit a reference signal to measure downlink channel conditions in a cellular system. In the 3GPP's LTE-A (Long Term Evolution Advanced) system, a terminal can measure the channel conditions between the base station and the terminal using the CRS or CSI-RS transmitted by the base station.

[0128] The above channel condition must be measured by considering various factors, which may include the amount of interference in the downlink. The amount of interference in the downlink includes interference signals and thermal noise generated by antennas belonging to adjacent base stations, and the amount of interference in the downlink is important for the terminal to determine the channel condition of the downlink. For example, when a base station with one transmit antenna transmits a signal to a terminal with one receive antenna, the terminal can determine the energy per symbol that can be received in the downlink from the reference signal received from the base station and the amount of interference that will be simultaneously received during the period of receiving the corresponding symbol, thereby determining Es / Io. The determined Es / Io is converted into a data transmission rate or an equivalent value and transmitted to the base station in the form of a channel quality indicator (CQI), which can be used by the base station to determine at what data transmission rate to perform transmission to the terminal.

[0129] Specifically, for example, in the LTE-A system, the terminal can feed back information about the channel status of the downlink to the base station so that the base station can utilize it for downlink scheduling. That is, the terminal can measure the reference signal transmitted by the base station in the downlink and feed back the information extracted from it to the base station in a form defined in the LTE / LTE-A standard. As described above, the information fed back by the terminal in LTE / LTE-A can be referred to as channel status information, and the channel status information can include the following three types of information.

[0130] - Rank Indicator (RI): The number of spatial layers that the terminal can receive in the current channel state.

[0131] - Precoding Matrix Indicator (PMI): An indicator of the precoding matrix preferred by the terminal in the current channel condition.

[0132] - Channel Quality Indicator (CQI): The maximum data rate that the terminal can receive in the current channel condition.

[0133] CQI can also be replaced by signal-to-interference plus noise ratio (SINR), maximum error correction code rate and modulation scheme, and data efficiency per frequency, which can be utilized similarly to maximum data rate.

[0134] The above RI, PMI, and CQI can be interrelated and have different meanings. For example, the precoding matrix supported by LTE / LTE-A is defined differently for each rank. Therefore, the PMI value X when RI has a value of 1 and the PMI value X when RI has a value of 2 can be interpreted differently.

[0135] In one embodiment, when a terminal determines a CQI, it may assume that the PMI value X that it notified to the base station is applied by the base station. In other words, when the terminal reports RI_X, PMI_Y, and CQI_Z to the base station, it may be equivalent to reporting that the terminal can receive a data rate corresponding to CQI_Z when the rank is RI_X and the PMI is PMI_Y. In this way, when the terminal calculates the CQI, it can assume which transmission method the base station will perform, and obtain optimized performance when actual transmission is performed using the transmission method.

[0136] In LTE / LTE-A, channel state information (RI, PMI, CQI) fed back by a terminal can be fed back in a periodic or aperiodic form. If a base station wishes to aperiodically acquire channel state information of a specific terminal, the base station can configure aperiodic feedback (or aperiodic channel state information reporting) using an aperiodic feedback indicator (or channel state information request field, channel state information request information) included in the downlink control information (DCI) for the terminal. In addition, if the terminal receives an indicator configured to perform aperiodic feedback in the nth subframe, the terminal can perform uplink transmission by including the aperiodic feedback information (or channel state information) in the data transmission in the (n+k)th subframe. Here, k is a parameter defined in the 3GPP LTE Release 11 standard, and can be defined as 4 for FDD (Frequency Division Duplexing) and as shown in [Table 7] for TDD (Time Division Duplexing).

[0137] [Table 7] Example of k values ​​for each subframe number n in TDD UL / DL configuration

[0138]

[0139] When aperiodic feedback is set, feedback information (or channel state information) includes RI, PMI, and CQI, and depending on the feedback setting (or channel state reporting setting), RI and PMI may not be fed back.

[0140] FIG. 6 is a diagram illustrating a process between a base station and a terminal when the base station has downlink data to transmit to a specific terminal according to one embodiment of the present disclosure.

[0141] In FIG. 6, at step 610, the base station (601) may transmit downlink control information (e.g., may include PDCCH, DCI, etc.) to the terminal (602).

[0142] According to one embodiment, the base station (601) may transmit DCI including PDSCH allocation information to the terminal (602) via the PDCCH. In this case, the terminal (602) may perform a blind decoding process to receive the DCI from the PDCCH resource. Through the blind decoding, the terminal (602) may confirm that the DCI has been transmitted to itself, and may receive downlink data (e.g., PDSCH, etc.) via the DCI at step 620. For example, the terminal that has received the DCI may recognize that data is transmitted via the PDSCH after information for PDSCH reception (e.g., K0 slot), and may receive the data at the corresponding location.

[0143] FIG. 7 is a diagram illustrating a communication system performing MU-MIMO transmission according to one embodiment of the present disclosure.

[0144] In relation to one embodiment, for terminals 1 (701) to 5 (705), if they all belong to the same set or group, it can be assumed that they are allocated the same time and frequency resources.

[0145] According to one embodiment, the base station (706) can transmit simultaneously to terminals 1 (701) to 5 (705) through different layers or different spatial resources, which may be an example of MU-MIMO. MU-MIMO may be a technology that can increase spectral efficiency by utilizing spatial resources in addition to limited time and frequency resources. As the number of antennas of the base station (706) increases, more layers can be utilized.

[0146] FIG. 8 is a diagram illustrating a DCI transmission process for transmitting scheduling information for performing MU-MIMO transmission, according to an embodiment of the present disclosure. According to an embodiment, FIG. 8 may be explained assuming that the PDCCH consists of one symbol on the time axis. In FIG. 8, among the PDCCH resources, the CCE or AL may be different for each UE, and each terminal may undergo a blind decoding process for the DCI transmitted to it. In addition, since the purpose is to transmit terminal-specific data, the DCI may need to be transmitted to each terminal separately.

[0147] According to FIG. 8, when MU DCI related to the present invention is not configured for each of terminals 1 (801) to 5 (805), it can be exemplified by resource allocation related to DCI transmission for each terminal. In addition, FIG. 8 can be exemplified by setting AL 1 for terminal 1 (801) and terminal 3 (803), AL 2 for terminal 2 (802) and terminal 5 (805), and AL 4 for terminal 4 (804), and it can be exemplified by setting information transmitted to each terminal to a different frequency on the frequency axis.

[0148] According to one embodiment, the DCI transmitted to each terminal may include the information of [Table 8]. [Table 8] may correspond to the notation based on the case when TimeDomainAllocationListForMultiPDSCH is not configured. [Table 8] may be exemplified as a DCI format (e.g., DCI Format 1_1) for scheduling one or more PDSCHs.

[0149] [Table 8] DCI Format 1_1

[0150]

[0151]

[0152] In the above [Table 8], the number of bits required for frequency resource allocation may vary depending on the type, but may require 19 bits based on the bandwidth supported by the defined standard. For example, in relation to frequency resource allocation, Type 0 may require up to 18 bits, Type 1 may require up to 16 bits, and dynamic switch may require 19 bits. In addition, as exemplified in [Table 8], the DCI information exemplified in the above table may include up to 119 bits of information. In addition, since a 24-bit CRC may be additionally required, up to 143 bits of information may be transmitted. In relation to this, when referring to the contents of [Table 9], which is an example related to the maximum number of supportable bits per AL, it may mean that the DCI must be transmitted using at least AL 2. According to one embodiment, [Table 9] may represent the maximum number of supportable bits per AL.

[0153] [Table 9] Example of maximum number of bits supported by CCE Aggregation Level

[0154]

[0155] In one embodiment, when scheduling more terminals for MU-MIMO transmission, even if spectral efficiency can be increased by utilizing many layers in terms of PDSCH transmission, if resources for transmitting DCI are insufficient to transmit all DCIs to terminals or more symbols are required, this may lead to a decrease in data channel efficiency due to inefficiency of the control channel.

[0156] Accordingly, according to one embodiment of the present disclosure, a method or device for transmitting DCI by allocating common control channel resources to terminals belonging to a candidate group of MU-MIMO scheduling may be considered.

[0157] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. Although embodiments of the present disclosure will be described below using LTE, LTE-A, or 5th generation mobile communication technology (5G, new radio, NR) systems as examples, embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, communication systems to which embodiments of the present disclosure are applied may also include 6th generation mobile communication technology (6G) developed after 5G. Therefore, embodiments of the present disclosure may be applied to other communication systems with some modifications within a scope that does not significantly deviate from the scope of the present disclosure, as determined by a person having skilled technical knowledge.

[0158] According to one embodiment, common control channel resources can be allocated to terminals belonging to a candidate group for MU-MIMO scheduling.

[0159] According to one embodiment, DCI information regarding resource allocation during MU-MIMO scheduling may be set identically for all terminals. Furthermore, specific DCI information may be set identically for all terminals depending on base station characteristics. That is, since terminals belonging to the same group may share the same time or frequency resources in relation to MU-MIMO, specific DCI information or DCI information regarding resource allocation may be set identically. For example, the common DCI information may include information in [Table 10] and [Table 11], respectively.

[0160] [Table 10]

[0161]

[0162] [Table 11]

[0163]

[0164] In relation to one embodiment, [Table 10] and [Table 11] may be exemplified as DCI format 1_1, and referring to [Table 10], field information on resources may include a carrier indicator including scheduling information related to multi-carrier, a bandwidth part indicator including scheduling information related to bandwidth part, a frequency domain resource assignment indicating information related to frequency resource allocation, and a time domain resource assignment indicating information related to time resource allocation, and may include a PDSCH-to-HARQ_feedback timing indicator field indicating information related to HARQ (hybrid automatic repeat request) feedback time related to retransmission.

[0165] Additionally, according to one embodiment, [Table 10] may be exemplified as information that can be set identically to a candidate group or terminal belonging to one group because it utilizes spatial resources in relation to MU-MIMO as information related to resources.

[0166] According to an embodiment, referring to [Table 11], the field information for resources may include a minimum applicable scheduling offset indicator indicating information on an offset value related to a PDSCH reception time, a VRB-to-PRB mapping (virtual resource block to physical resource block mapping) indicating information related to whether interleaved mapping is performed, a PRB bundling size indicator indicating information on static or dynamic bundling for PRB bundling, and a Rate matching indicator field which is information related to rate matching.

[0167] Additionally, according to one embodiment, [Table 11] may be exemplified as information that can be set identically to a candidate group or terminal belonging to one group in relation to base station operation, etc.

[0168] In relation to one embodiment, in an MU-MIMO environment, MU DCI may correspond to information that can be set identically to a candidate group or terminal belonging to one group in relation to one embodiment, and may include at least one piece of information of [Table 10] and [Table 11] exemplified above. Information that can be set identically to a candidate group or terminal belonging to one group or multi-user for MU-MIMO or other communication technologies that transmit using spatial resources may be exemplified as MU DCI, and may correspond to DCI including the same information or DCI having a similar function or similar purpose, without being limited to the above expression.

[0169] In relation to one embodiment, [Table 10] and [Table 11] exemplify information (MU DCI) that can be set identically to a candidate group or terminal belonging to one group in the information exemplified by DCI format 1_1, but this is only an example, and MU DCI may include information not included in [Table 10] and [Table 11] in relation to DCI format 1_1, and may be exemplified as information that is set identically by partially including one or more pieces of information included in [Table 10] and [Table 11].

[0170] According to [Table 10] and [Table 11], the amount of information that can be set identically, for example, in MU scheduling, can be up to 36 bits by adding the number of bits in each field. Therefore, the information that can be set identically can be transmitted as MU DCI to efficiently use resources.

[0171] According to [Table 8], [Table 10], and [Table 11], the common information amount of terminals receiving MU scheduling, etc. can be calculated as 31 to 36 bits through simple arithmetic, and the different information amount for each terminal can be calculated as a minimum of 19 bits and a maximum of 88 bits. At this time, when the base station performs MU scheduling on N terminals, the amount of information that must be transmitted may require 50N to 121N bits in the existing method, excluding CRC bits. According to one embodiment of the present invention, 31 to 36 bits + 19N to 88N bits are required, and as N increases, that is, as a number of terminals receive MU scheduling, the effect related to one embodiment may increase.

[0172] Also, in relation to one embodiment, although [Table 10] and [Table 11] are exemplified in relation to DCI format 1_1, it can also be applied to other DCI formats.

[0173] Additionally, in relation to one embodiment, information (MU DCI) that can be set identically to a group of candidates or terminals belonging to one group can be dynamically changed depending on the situation of the base station.

[0174] Additionally, in relation to one embodiment, certain information may be excluded from one or more pieces of information (MU DCI) that are set to be common through a specific indicator, etc., and certain information may be added.

[0175] FIG. 9 is a diagram illustrating DCI transmission via PDCCH in relation to MU-MIMO according to one embodiment of the present disclosure.

[0176] According to one embodiment, since terminals 1 to 5 are allocated time and space resources together, MU DCI (910) related to MU-MIMO according to one embodiment can be equally allocated to the corresponding terminals.

[0177] According to FIG. 9, MU DCI (910) can be simultaneously transmitted to multiple terminals (multi-users). For example, MU DCI (910) can have information that can be common to a group of candidates or terminals belonging to the same group from terminal 1 to terminal 5.

[0178] According to one embodiment, terminals that have received MU DCI (910) may additionally receive DCI allocated to each terminal for terminal-specific data reception.

[0179] According to one embodiment, the additional DCI may be exemplified as a reduced DCI (901) related to terminal 1, a reduced DCI (902) related to terminal 2, a reduced DCI (903) related to terminal 3, a reduced DCI (904) related to terminal 4, and a reduced DCI (905) related to terminal 5, as described below in FIG. 9. Alternatively, it may be exemplified as a DCI for a specific terminal (e.g., a DCI for terminal 1). By receiving such additional DCI, control information that needs to be distinguished between terminals can be transmitted. The fields defined in the corresponding DCI may be set so as not to overlap with the field values ​​set in the MU DCI.

[0180] In relation to one embodiment, the DCI (901 to 905) additionally allocated to each terminal for terminal-specific data reception may correspond to DCI or reduced DCI for a specific terminal. The DCI is not limited to the DCI or reduced DCI expression for the specific terminal, and may refer to DCI containing the same information or DCI having a similar function or similar purpose.

[0181] Additionally, DCI or reduced DCI for a specific terminal may include terminal-specific information excluding information common to a group, etc. transmitted via MU DCI, or may include some information common to a group, etc., and may be changed according to settings according to the base station environment or terminal environment.

[0182] FIG. 10 is a diagram illustrating a base station and terminal signaling process according to one embodiment of the present disclosure.

[0183] According to FIG. 10, in step 1010, the base station (1001) may transmit a message including control information (e.g., may include PDCCH, DCI, etc.) to the terminal (1002).

[0184] According to one embodiment, the message of step 1010 may include MU DCI, DCI for a specific terminal, or reduced DCI.

[0185] In one embodiment, when receiving DCI via PDCCH in step 1010, MU DCI may be received first and then the reduced DCI, or depending on the situation, the reduced DCI may be received first and then the MU DCI, and depending on one embodiment, only a part of MU DCI or the reduced DCI may be included in the message.

[0186] In step 1020, the terminal can decode the MU DCI of the received message through a blind decoding process, and can also decode the reduced DCI.

[0187] According to one embodiment, the decoding or blind decoding process of the reduced DCI may be performed based on the MU DCI or the decoding-related information included in the message, which will be described later.

[0188] In step 1030, the base station (1001) may transmit downlink data (e.g., PDSCH, etc.) to the terminal (1002). According to one embodiment, the terminal may receive the PDSCH based on the message received in step 1010, and information related to PDSCH reception (e.g., K0) may be used during the reception process.

[0189] According to one embodiment, step 1030 may be omitted depending on the information in the message received in step 1010, and according to one embodiment, multiple PDSCHs may be transmitted from the base station (1001) to the terminal (1002).

[0190] FIG. 11 is a diagram illustrating a base station and terminal signaling process according to one embodiment of the present disclosure.

[0191] According to FIG. 11, in step 1110, a message (e.g., an RRC message) containing information that can be configured to receive MU DCI or reduced DCI may be transmitted from the base station (1101) to the terminal (1102).

[0192] In some embodiments, the use of MU DCI and reduced DCI may require configuration (e.g., via RRC) of the terminal. This may correspond to configuration information for receiving MU DCI or reduced DCI. Specifically, for example, the information for configuring the terminal may utilize existing RRC information elements (IEs) or fields, or may be defined via additional IEs or fields.

[0193] According to one embodiment, a DCI format may be determined in relation to the above configuration. The UE may be notified, through RRC configuration or the like, that the format can be transmitted by configuring a region (e.g., a search space) in which a downlink control channel (PDCCH) can be transmitted. Information according to the DCI format may be included in additional configuration information.

[0194] According to one embodiment, the same scheduling information may be transmitted to at least one terminal among the terminals that are candidates for receiving MU DCI. To this end, a separate or new DCI format may be defined. For example, it may be defined in a format such as DCI format x_y (where x and y may correspond to integers greater than or equal to 0) in relation to a method supported by 5G or NR.

[0195] In one embodiment, an additional form of search space may be defined for MU DCI reception by the terminal.

[0196] According to one embodiment, [Table 12] may represent a partial example for a case where the format related to MU DCI is defined as format 3_0, etc.

[0197] Additionally, the information in [Table 12] may correspond to information included in the IE related to the search space within the RRC message.

[0198] [Table 12]

[0199]

[0200] According to one embodiment, a search space related to MU DCI is characterized in that it is a search space shared between a set of specific terminals (for example, shared between multiple terminals that are set as a group through the same group or specific criteria, etc. in relation to MU-MIMO), unlike a terminal-specific search space that is defined previously and a common search space that is shared by all terminals. The search space related to the MU DCI may be exemplified as an MU-specific search space (Multi-User-specific Search Space, MUSS), and is not limited to the above examples, and may include search spaces having similar functions or purposes.

[0201] According to one embodiment, the search space may be exemplified by a UE-specific search space (USS), a common search space (CSS), and a multi user-specific search space (MUSS), and the message transmitted in step 1110 may include information about at least one of the above search spaces.

[0202] [Table 13] can show an example of the maximum number of AL and blind decoding of CCEs that can be supported in the search space as MUSS is defined.

[0203] [Table 13]

[0204]

[0205] In one embodiment, a form that utilizes an existing field (e.g., CSS (common search space) or USS (UE-specific search space)) rather than an additional form for MUSS may also be considered.

[0206] In one embodiment, when MU-MIMO or MU DCU related MUSS is set, information common to a specific group or set (e.g., MU DCI) rather than all terminals or one terminal may be transmitted.

[0207] According to one embodiment, an RNTI associated with the MU DCI may be defined to distinguish the MU DCI from other DCIs. The RNTI associated with the MU DCI may be exemplified by an MU RNTI, and the MU RNTI may include indicator information for a set associated with MU-MIMO. Accordingly, terminals belonging to the corresponding set may identify the MU DCI to be received through the MU RNTI. The terminology is not limited to the above-described terminology, and may include RNTIs having similar functions or purposes.

[0208] In step 1110, information of MU RNTI can be transmitted from the base station (1101) to the terminal (1102) through a message (e.g., an RRC message), and the message can include information such as [Table 14].

[0209] According to one embodiment, [Table 14] may exemplify configuration information (e.g., information related to MU scheduling) that is set in advance for MU-MIMO scheduling along with MU-RNTI.

[0210] According to [Table 14], information related to MU scheduling may include at least one of the following: size information of MU DCI, information on how many sets of MU-MIMO candidate groups or related terminals are formed, information on the maximum number, information on which set the terminal belongs to, and setting information on the maximum number or number of times AL and blind decoding are performed when transmitting MU DCI. In addition, the above-listed information may be configured differently depending on the set or group related to MU-MIMO.

[0211] [Table 14]

[0212]

[0213] In some embodiments, since the reduced DCI can be configured through a terminal-specific search space (USS), a definition of the relevant format may be required. Similar to MU DCI, the reduced DCI can also be defined according to the relevant format. For example, it can be defined as DCI format x_y (where x and y are integers greater than or equal to 0), similar to the method supported by existing 5G or NR.

[0214] In one embodiment, the format associated with the reduced DCI may be defined as format 3_1, etc.

[0215] According to one embodiment, [Table 15] may represent a partial example for a case where the format related to the reduced DCI is defined as format 3_1, etc. In addition, the information in [Table 15] may correspond to information included in an IE related to a search space within an RRC message.

[0216] [Table 15]

[0217]

[0218] According to FIG. 11, in step 1120, the base station (1101) may transmit a message including control information (e.g., may include PDCCH, DCI, etc.) to the terminal (1102).

[0219] According to one embodiment, the message of step 1120 may include MU DCI, DCI for a specific terminal (or, reduced DCI).

[0220] In one embodiment, when receiving DCI via PDCCH in step 1120, MU DCI may be received first and then the reduced DCI, or depending on the situation, the reduced DCI may be received first and then the MU DCI, and depending on one embodiment, only a part of MU DCI or the reduced DCI may be included in the message.

[0221] At step 1130, the terminal can decode the MU DCI of the received message through a blind decoding process, and can also decode the reduced DCI.

[0222] According to one embodiment, the decoding or blind decoding process of the reduced DCI may be performed based on the MU DCI or the decoding-related information included in the message, which will be described later.

[0223] In step 1140, the base station (1101) may transmit downlink data (e.g., PDSCH, etc.) to the terminal (1102). According to one embodiment, the terminal may receive the PDSCH based on the message received in step 1120, and information related to PDSCH reception (e.g., K0) (1103) may be used during the reception process.

[0224] According to one embodiment, step 1140 may be omitted depending on the information in the message received in step 1120, and according to one embodiment, multiple PDSCHs may be transmitted from the base station (1101) to the terminal (1102).

[0225] FIG. 12 illustrates a method for setting up multiple groups or sets in relation to MU-MIMO, according to one embodiment of the present disclosure.

[0226] FIG. 12 illustrates a case in which terminals 1 (1201) to 5 (1205) can be divided into set #1 (1210) and set #2 (1220) according to one embodiment of the present disclosure.

[0227] A base station (1206) or the like may determine whether to include specific terminals in a certain set based on arbitrary criteria (e.g., terminal location, direction, distance, channel-related information, or other information). For example, terminals within a certain range of distances may be included in a single group or set.

[0228] Additionally, arbitrary criteria may be applied in relation to other technologies for efficient use of spatial resources in relation to MU-MIMO.

[0229] According to FIG. 12, in relation to MU-MIMO, it is exemplified that two sets, set #1 (1210) and set #2 (1220), are configured according to arbitrary criteria. Set #1 (1210) may include terminal 1 (1201), terminal 3 (1203), and terminal 5 (1205) related to arbitrary criteria, and set #2 (1220) may include terminal 2 (1202) and terminal 4 (1204) related to another arbitrary criteria.

[0230] According to FIG. 12, terminal 1 (1201), terminal 3 (1203), and terminal 5 (1205) belonging to set #1 (1210) can receive information (e.g., MU DCI) to be transmitted commonly to each terminal from base station (1206) related to set #1 (1210) at the same frequency or same time resource. In addition, terminal 2 (1202) and terminal 4 (1204) belonging to set #2 (1220) can receive information (e.g., MU DCI) to be transmitted commonly to each terminal at the same frequency or same time resource.

[0231] FIG. 13 illustrates an example of a form in which DCI is transmitted to each set or terminal through a PDCCH in an MU-MIMO environment according to one embodiment of the present disclosure.

[0232] According to Fig. 13, it can be composed of set #1 and set #2, which are sets for each multi-user, according to arbitrary criteria. Set #1 can include terminal 1, terminal 3, and terminal 5 related to arbitrary criteria, and set #2 can include terminal 2 and terminal 4 related to another arbitrary criteria.

[0233] In FIG. 13, the base station can transmit information that may be common to terminals included in set #1 through set #1 MU DCI (1310). Similarly, information that may be common to terminals included in set #2 can be transmitted through set #2 MU DCI (1320).

[0234] According to one embodiment, each terminal may receive DCI (or reduced DCI) for each terminal. Specifically, for example, each terminal may receive reduced DCI (1301) associated with terminal 1, reduced DCI (1302) associated with terminal 2, reduced DCI (1303) associated with terminal 3, reduced DCI (1304) associated with terminal 4, and reduced DCI (1305) associated with terminal 5.

[0235] In one embodiment, each set may have a different AL set, and when set to each different set, different information may be set.

[0236] Additionally, with respect to one embodiment, each terminal within the same set may be set to a different AL, or may be set to the same AL. For example, with respect to terminals 1, 3, and 5 that may belong to set #1, MU DCI (1310) may be set to AL 1, and with respect to terminals 2 and 4 that may belong to set #2, MU DCI (1320) may be set to AL 2.

[0237] Additionally, according to FIG. 13, the DCI (or reduced DCI) for each terminal may have different ALs.

[0238] According to one embodiment, terminals belonging to set #1 may blind decode reduced DCI for terminal-specific information after blind decoding MU DCI (1310) associated with set #1. Additionally, terminals belonging to set #2 may blind decode reduced DCI for terminal-specific information after blind decoding MU DCI (1320) associated with set #2.

[0239] FIG. 14a and FIG. 14b illustrate that setting information is transmitted differently to each terminal as different information is set in each set according to one embodiment of the present disclosure.

[0240] Figures 14a and 14b may correspond to a process in which each terminal receives information related to settings to receive MU DCI.

[0241] According to one embodiment, RRC configuration information (e.g., information related to MU scheduling, etc.) can be transmitted to terminals belonging to each group, and terminals belonging to the same group can receive the same information.

[0242] According to FIG. 14A, the base station (1406) can transmit first information to terminal 1 (1401) belonging to set #1 through step 1410. The first information can be included in a message (e.g., an RRC message) that the base station (1406) transmits to terminal 1 (1401). In addition, through steps 1420 and 1430, the base station (1406) can equally transmit the first information to other terminals belonging to set #1, terminal 3 (1403) and terminal 5 (1405). Alternatively, the first information can be included in a message (e.g., an RRC message) transmitted to each terminal and transmitted.

[0243] According to one embodiment, the first information may correspond to configuration information for receiving MU DCI or reduced DCI (reduced DCI specific to each terminal) for each terminal related to set #1, and the first information may correspond to information related to MU scheduling for set #1.

[0244] Thereafter, each terminal can receive MU DCI related to set #1 or reduced DCI for each terminal (reduced DCI specific to each terminal) based on the first information from the base station (1406), and can also receive data (e.g., PDSCH) through the received DCIs.

[0245] According to FIG. 14b, the base station (1406) can transmit second information to terminal 2 (1402) belonging to set #2 through step 1440. The second information can be included in a message (e.g., an RRC message) that the base station (1406) transmits to terminal 2 (1402). In addition, the base station (1406) can transmit the second information to terminal 4 (1404), which is another terminal belonging to set #2, through step 1450. Alternatively, the second information can be included in a message (e.g., an RRC message) transmitted to terminal 4 (1404) and transmitted.

[0246] Additionally, according to one embodiment, the second information may correspond to configuration information for receiving MU DCI related to set #2 or DCI for each terminal or reduced DCI (reduced DCI specific to each terminal) for each terminal, and the second information may correspond to information related to MU scheduling related to set #2.

[0247] Thereafter, each terminal can receive MU DCI related to set #2 or reduced DCI for each terminal (reduced DCI specific to each terminal) based on the second information from the base station (1406), and can also receive data (e.g., PDSCH) through the received DCIs.

[0248] FIG. 15 illustrates a process for changing setting information set for terminals in a specific set according to one embodiment of the present disclosure.

[0249] FIG. 15 illustrates an example of changing setting information set for each terminal in set #1, which may include terminal 1 (1501), terminal 3 (1503), and terminal 5 (1505), according to one embodiment.

[0250] Additionally, FIG. 15 may be exemplified as a process for changing RRC configuration information related to set #1. For example, the configuration information may be changed to change AL, such as when the long-term channel conditions of a specific set (e.g., set #1) change, or to adjust the number of candidates for blind decoding, the size related to DCI, etc.

[0251] According to FIG. 15, in step 1510, the base station (1506) may transmit information for changing configuration information to terminal 1 (1501). The information for changing the configuration information may correspond to information for changing information set for receiving MU DCI or reduced DCI related to one embodiment.

[0252] Additionally, prior to step 1510 with respect to terminal 1 (1501), terminal 1 (1501) may receive configuration information from base station (1506) to receive the first MU DCI or reduced DCI, and after step 1510, to further change the configuration for terminal 1 (1501), base station (1506) may transmit other information for changing the configuration information for terminal 1 (1501).

[0253] According to FIG. 15, in steps 1520 and 1530, the base station (1506) may transmit information for changing configuration information to terminal 3 (1503) or terminal 5 (1505), respectively. The information for changing the configuration information may correspond to information for changing information set for receiving MU DCI or reduced DCI related to set #1, according to one embodiment.

[0254] Additionally, prior to step 1520 or step 1530 related to terminal 3 (1503) or terminal 5 (1505), configuration information for receiving the first MU DCI or reduced DCI may be received by terminal 3 (1503) or terminal 5 (1505) from the base station (1506), and after step 1520 or step 1530, in order to further change the configuration for terminal 3 (1503) or terminal 5 (1505), the base station (1506) may transmit other information for changing the configuration information for terminal 3 (1503) or terminal 5 (1505).

[0255] Additionally, the information for changing the setting information transmitted in each step 1510, step 1520, or step 1530 may correspond to the same information for changing the setting in relation to set #1.

[0256] According to one embodiment, the process for making the additional change is not limited in number of times, and the change may correspond to deleting already set information or may correspond to adding new information.

[0257] In one embodiment, for a terminal with changed settings, the terminal may receive MU DCI and reduced DCI related to the set to which the terminal belongs based on the changed settings.

[0258] FIG. 16 illustrates a process of a specific terminal changing a set in relation to MU-MIMO according to one embodiment of the present disclosure.

[0259] FIG. 16 illustrates an example in which terminal 1 (1601) belonging to set #1 (1610) changes from set #1 (1610) to set #2 (1620) to which terminal 2 (1602) and terminal 4 (1604) belong in a specific situation. For example, the process of changing the set of a specific terminal may be performed when the terminal moves, when the long-term channel of a specific terminal within the set drops, when a specific condition or criterion is not met, when another condition or criterion is met, or according to any other situation.

[0260] According to one embodiment, at step 1630, the base station (1606) may change the set by transmitting information for changing the set (e.g., information for resetting MU scheduling information, etc.) to terminal 1 (1601). The information for changing the set may include an MU-RNTI related to set #2, a set indicator, and information related to [Table 14].

[0261] According to one embodiment, the information for changing the set may be included in a message (e.g., an RRC message) that the base station sends to the terminal.

[0262] In one embodiment, when one or more terminals (e.g., terminal 1 (1601) and terminal 2 (1602) etc.) are to be changed to the same group or set, the same information may be transmitted to the one or more terminals (e.g., terminal 1 (1601) and terminal 2 (1602) etc.) for resetting.

[0263] According to one embodiment, prior to step 1630 with respect to terminal 1 (1601), configuration information or MU scheduling information related to set #1 may be received from the base station (1606) to receive MU DCI or reduced DCI related to the initial set #1 (1610), and after step 1630, in order to further change the set for terminal 1 (1601), the base station (1606) may transmit information for set change to terminal 1 (1601).

[0264] According to one embodiment, terminal 1 (1601) may receive information for a set change and change to set #2 (1620), and thus receive MU DCI related to set #2 (1620) and reduced DCI related to terminal 1.

[0265] FIG. 17 illustrates a method for improving the efficiency of a blind decoding process of a terminal in performing a method of allocating common control channel resources to terminals belonging to a candidate group of scheduling related to MU-MIMO or terminals belonging to each set, according to one embodiment of the present disclosure.

[0266] In one embodiment, when fields of MU DCI related to a set of MU-MIMO are configured, the MU DCI may include additional fields for the terminal to efficiently receive or decode the reduced DCI related to the present disclosure. [Table 16] may correspond to examples of specific fields to be added in relation to one embodiment.

[0267] [Table 16]

[0268]

[0269] According to one embodiment, the base station may transmit MU DCI (1710) related to a set of MU-MIMO to the terminal, and may include information (e.g., information exemplified in [Table 16]) for efficiently decoding the reduced DCI transmitted to each terminal in the MU DCI (1710).

[0270] With respect to [Table 16], the example search space restriction field may include information related to the location of the reduced DCI of each terminal within the set related to the MU-MIMO, so that the terminal can efficiently perform blind decoding based on the search space restriction field. In one embodiment, the setting of the search space restriction field may utilize a method similar to the method of frequency domain resource allocation in the existing DCI, and if the existing unit was PRB, the field may be calculated in units of CCE. In addition, the information related to the location may be defined or calculated based on the location of the MU DCI (1710).

[0271] With respect to [Table 16], the illustrated AL restriction field notifies information related to the AL of each terminal within the set related to the MU-MIMO, so that the terminal can efficiently perform blind decoding on the reduced DCI based on the AL restriction field. For example, each terminal can perform blind decoding based on the AL restriction field when blind decoding the reduced DCI. The AL restriction field may include an AL value used in a bitmap manner. In addition, in one embodiment, with respect to the method of notifying the AL value, it may be possible to convey it in various forms, such as a method of notifying a difference value based on information of the AL used in the MU DCI of the set.

[0272] According to FIG. 17, for example, when MU DCI (1710) includes information related to search space limitation, terminal 2 can receive location information of reduced DCI (1702) related to terminal 2 through MU DCI (1710) and blind decode the reduced DCI (1702). The location information can be explicitly or implicitly conveyed to terminal 2 through MU DCI.

[0273] According to FIG. 17, for example, when MU DCI (1710) includes information related to AL limitation, terminal 4 can blindly decode the reduced DCI (1704) related to terminal 4 by receiving AL information (e.g., information related to AL value 2) of the reduced DCI (1704) through MU DCI (1710). The AL related information can be explicitly or implicitly conveyed to terminal 4 through MU DCI.

[0274] The search space restriction field or AL restriction field is merely an example of information for efficient blind decoding in relation to MU DCI and is not limited to the above term and may refer to information having a similar function or purpose.

[0275] Additionally, according to one embodiment, information related to additional fields for efficiently receiving or decoding the reduced DCI may be transmitted to the terminals through existing fields in the MU DCI, or may be transmitted to the terminals through new fields in the MU DCI.

[0276] FIG. 18 is a drawing showing an example of a terminal structure according to one embodiment of the present disclosure.

[0277] Referring to FIG. 18, a terminal (1800) according to an embodiment of the present disclosure may be configured to include a control unit (1810), a transceiver unit (1820), and a memory (1830). In the present disclosure, the control unit (1810) of the terminal (1800) may be defined as a circuit or an application-specific integrated circuit or at least one processor.

[0278] The control unit (1810) can control the overall operation of the terminal (1800) according to an embodiment proposed in the present disclosure. For example, the control unit (1810) can control the signal flow between each block to perform operations according to the drawing (or, flowchart, flow chart) described above.

[0279] The transceiver (1820) can transmit and receive signals. The transceiver (1820) can transmit signals to a node or base station according to an embodiment of the present disclosure, and receive signals from the node or base station, for example.

[0280] The memory (1830) can store at least one of information transmitted and received through the transceiver (1820) and information generated through the control unit (1810). In addition, the memory (1830) can be defined as a storage unit.

[0281] FIG. 19 is a drawing showing an example of the structure of a base station according to one embodiment of the present disclosure.

[0282] Referring to FIG. 19, a base station (1900) according to an embodiment of the present disclosure may be configured to include a control unit (1910), a transceiver unit (1920), and a memory (1930). In the present disclosure, the control unit (1910) of the base station (1900) may be defined as a circuit or an application-specific integrated circuit or at least one processor.

[0283] The control unit (1910) can control the overall operation according to an embodiment proposed in the present disclosure. For example, the control unit (1910) can control the signal flow between each block to perform the operation according to the drawing (or, flowchart, flow chart) described above.

[0284] The transceiver (1920) can transmit and receive signals. The transceiver (1920) can transmit signals to a terminal or node according to an embodiment of the present disclosure, and receive signals from the terminal or node, for example.

[0285] The memory (1930) can store at least one of information transmitted and received through the transceiver (1920) and information generated through the control unit (1910). In addition, the memory (1930) can be defined as a storage unit.

[0286] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0287] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of the present disclosure.

[0288] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0289] Additionally, the program may be stored on an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device implementing an embodiment of the present disclosure via an external port.

[0290] Additionally, a separate storage device on a communications network may be connected to a device performing an embodiment of the present disclosure.

[0291] In the specific embodiments of the present disclosure described above, components included in the present disclosure are expressed in the singular or plural form, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in the plural form may be composed of singular elements, or components expressed in the singular form may be composed of plural elements.

[0292] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples presented to easily explain the technical content of the present disclosure and aid in understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it will be apparent to those skilled in the art to which the present disclosure pertains that other modified examples based on the technical concepts of the present disclosure are possible.

[0293] Additionally, each of the above embodiments can be combined and operated as needed.

[0294] Meanwhile, the order of description in the drawings explaining the method of the present disclosure does not necessarily correspond to the order of execution, and the order of precedence may be changed or executed in parallel.

[0295] Alternatively, the drawings illustrating the method of the present disclosure may omit some components and include only some components without detracting from the essence of the present disclosure.

[0296] In addition, the method of the present disclosure may be implemented by combining some or all of the contents included in each embodiment within a scope that does not harm the essence of the present disclosure.

[0297] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples presented to easily explain the technical content of the present disclosure and help understand the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it will be apparent to those skilled in the art to which the present disclosure pertains that other modified examples based on the technical concept of the present disclosure are possible. In addition, each of the above embodiments can be combined and operated as needed. For example, all of the embodiments of the present disclosure can be operated by combining parts with each other.

Claims

1. In a method performed by a terminal of a wireless communication system, A step of receiving MU (multi-user) DCI (downlink control information) related to MU-MIMO (multi-user multiple input multiple output) from a base station; A step of receiving DCI for the terminal from the base station; and A step of receiving a downlink data channel from the base station based on the MU DCI and the DCI for the terminal, A method characterized in that the above MU DCI is transmitted to a group including at least one terminal through the same time and same frequency resources.

2. In paragraph 1, A method characterized in that the MU DCI includes information related to scheduling of the downlink data channel common to at least one terminal in the group.

3. In paragraph 2, A method characterized in that the information includes at least one of time resource allocation information, frequency resource allocation information, HARQ (hybrid automatic repeat request) feedback-related information, one or more indicator information related to the scheduling, or offset information related to the scheduling.

4. In paragraph 1, A method comprising the step of receiving a first message for receiving the MU DCI from the base station.

5. In paragraph 4, A method characterized in that the first message includes at least one of information about a search space for MU DCI reception or information about a radio network temporary identifier (RNTI).

6. In paragraph 4, A method comprising the step of receiving a second message from the base station for changing information for receiving the MU DCI.

7. In paragraph 1, A method characterized in that the above MU DCI includes information for receiving DCI for the terminal.

8. In paragraph 7, A method characterized in that the information for receiving DCI for the terminal includes at least one of information related to an allocation location of DCI for the terminal or information about an aggregation level (AL).

9. In a method performed by a base station of a wireless communication system, A step of transmitting MU (multi-user) DCI (downlink control information) related to MU-MIMO (multi-user multiple input multiple output) to a terminal; a step of transmitting DCI for the terminal to the terminal; and A step of transmitting a downlink data channel to the terminal is included, A method characterized in that the above MU DCI is transmitted to a group including at least one terminal through the same time and same frequency resources.

10. In paragraph 9, A method characterized in that the MU DCI includes information related to scheduling of the downlink data channel common to at least one terminal in the group.

11. In paragraph 10, A method characterized in that the information includes at least one of time resource allocation information, frequency resource allocation information, HARQ (hybrid automatic repeat request) feedback-related information, one or more indicator information related to the scheduling, or offset information related to the scheduling.

12. In paragraph 9, A method comprising the step of transmitting a first message for receiving the MU DCI of the terminal to the terminal.

13. In paragraph 12, A method characterized in that the first message includes at least one of information about a search space for MU DCI reception of the terminal or information about a radio network temporary identifier (RNTI).

14. In paragraph 12, A method comprising the step of transmitting a second message to the terminal for changing information for receiving the MU DCI of the terminal.

15. In paragraph 9, A method characterized in that the MU DCI includes information for the terminal to receive DCI for the terminal.

16. In paragraph 15, A method characterized in that the information for the terminal to receive DCI for the terminal includes at least one of information related to an allocation location of the DCI for the terminal or information about an aggregation level (AL).

17. In the terminal of a wireless communication system, Transmitter and receiver; and A control unit connected to the above transceiver, receiving MU (multi-user) DCI (downlink control information) related to MU-MIMO (multi-user multiple input multiple output) from a base station, receiving DCI for the terminal from the base station, and receiving a downlink data channel from the base station based on the MU DCI and the DCI for the terminal, A terminal characterized in that the above MU DCI is transmitted to a group including at least one terminal through the same time and same frequency resources.

18. In paragraph 17, A terminal characterized in that the MU DCI includes information related to scheduling of the downlink data channel common to at least one terminal in the group.

19. In paragraph 18, A terminal characterized in that the above information includes at least one of time resource allocation information, frequency resource allocation information, HARQ (hybrid automatic repeat request) feedback-related information, one or more indicator information related to the scheduling, or offset information related to the scheduling.

20. In the 17th paragraph, the control unit, A terminal that receives a first message for receiving the above MU DCI from the base station.

21. In paragraph 20, A terminal characterized in that the first message includes at least one of information about a search space for MU DCI reception or information about a radio network temporary identifier (RNTI).

22. In paragraph 20, the control unit, A terminal that receives a second message from the base station for changing information for receiving the above MU DCI.

23. In paragraph 17, A terminal, characterized in that the above MU DCI includes information for receiving DCI for the terminal.

24. In paragraph 23, A terminal characterized in that the information for receiving DCI for the terminal includes at least one of information related to an allocation location of DCI for the terminal or information about an aggregation level (AL).

25. In a base station of a wireless communication system, Transmitter and receiver; and A control unit connected to the above transceiver unit, transmitting MU (multi-user) DCI (downlink control information) related to MU-MIMO (multi-user multiple input multiple output) to a terminal, transmitting DCI for the terminal to the terminal, and transmitting a downlink data channel to the terminal, A base station, characterized in that the above MU DCI is transmitted to a group including at least one terminal through the same time and same frequency resources.

26. In paragraph 25, A base station, characterized in that the MU DCI includes information related to scheduling of the downlink data channel common to at least one terminal in the group.

27. In paragraph 26, A base station, characterized in that the information includes at least one of time resource allocation information, frequency resource allocation information, HARQ (hybrid automatic repeat request) feedback-related information, one or more indicator information related to the scheduling, or offset information related to the scheduling.

28. In paragraph 25, the control unit, A base station that transmits a first message for receiving the MU DCI of the terminal to the terminal.

29. In paragraph 28, A base station, characterized in that the first message includes at least one of information about a search space for MU DCI reception of the terminal or information about a radio network temporary identifier (RNTI).

30. In paragraph 28, the control unit, A base station that transmits a second message to the terminal for changing information for receiving the MU DCI of the terminal.

31. In paragraph 25, A base station, characterized in that the above MU DCI includes information for the terminal to receive DCI for the terminal.

32. In paragraph 31, A base station, characterized in that the information for the terminal to receive DCI for the terminal includes at least one of information related to an allocation location of the DCI for the terminal or information about an aggregation level (AL).

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